[PATCH v8 00/18] media: cadence,ti: CSI2RX Multistream Support

[PATCH v8 00/18] media: cadence,ti: CSI2RX Multistream Support

[Rishikesh Donadkar]

This series adds multi-stream support and PM support for Cadence CSI2RX
and TI CSI2RX SHIM drivers.

PM patches are picked from:
https://lore.kernel.org/all/20250902-ti_csi_pm-v2-0-59a3be199940@ideasonboard.com/

PATCH 01 :    Remove word size alignment restriction on frame width
PATCH 02-09:  Support multiple DMA contexts/video nodes in TI CSI2RX
PATCH 10-11:  Use get_frame_desc to propagate virtual channel
              information across Cadence and TI CSI-RX subdevs
PATCH 12-13:  Use new multi-stream APIs across the drivers to support
              multiplexed cameras from sources like UB960 (FPDLink)
PATCH 14:     Optimize stream on by submitting all queued buffers to DMA
PATCH 15:     Change the drain architecture to support multi-stream and
              implement completion barriers for last drain.
PATCH 16-18:  Runtime PM and System PM support for CSI-RX.

Testing for this series has been done on top of media tree with 4x IMX219
camera modules connected to TI's AM62A using V3 Link fusion mini board.

Overlay and defconfig changes for the same can be found below:
https://github.com/RISHI27-dot/linux/commits/u/multistream_v8

v4l2-compliance results:
https://gist.github.com/Rishikesh-D/c43ff1653ef59f2eb81ea76bd56780a4

---
Changes in v8:

# New patches in v8:
[PATCH v8 07/18] media: cadence: csi2rx: Move to .enable/disable_streams API
[PATCH v8 08/18] media: ti: j721e-csi2rx: Move to .enable/disable_streams API
- Remove the s_stream API and use the enable/disable_streams API right
  after adding the subdev for core device

Changes:
[PATCH v8 01/18] media: ti: j721e-csi2rx: Remove word size alignment on frame width
- Remove define for PSIL_WORD_SIZE_BYTES.
[PATCH v8 06/18] media: ti: j721e-csi2rx: add a subdev for the core device
- Use v4l2_subdev_state_get_format() instead of using the get_fmt from the 
  subdev pad ops in the ti_csi2rx_link_validate() function.
[PATCH v8 11/18] media: ti: j721e-csi2rx: add support for processing virtual channels
- Move routing support form this patch to PATCH 13/18.
[PATCH v8 12/18] media: cadence: csi2rx: add multistream support
- Move support for enable/disable_streams() API that was added in this patch to
  PATCH 07/18 earlier in this series.
- Remove the mutex from the driver
[PATCH v8 13/18] media: ti: j721e-csi2rx: add multistream support
- Move support for enable/disable_streams() API that was added in this patch to
  PATCH 08/18 earlier in this series.
- Remove csi->mutex protection inside enable/disable_streams() function calls to
  solve circular locking dependency warning.
- Mention that DT filtering is also supported in the commit message.

Link to (v7):
https://lore.kernel.org/all/20250911102832.1583440-1-r-donadkar@ti.com/#t

---
Changes in v7:

[PATCH v6 03/16] media: ti: j721e-csi2rx: separate out device and context
- Resolve bisect test fail because of undefined 'csi' variable
- Resolve bisect test fail because of 'vdev' not being in scope when used
[PATCH v6 07/16] media: ti: j721e-csi2rx: get number of contexts from device tree
- Resolve compiler warning regarding missing error code 'ret'
[PATCH v6 12/16] media: ti: j721e-csi2rx: Submit all available buffers
- Remove unused variable

Link to (v6):
https://lore.kernel.org/all/20250908134729.3940366-1-r-donadkar@ti.com/

---
Changes in v6:

# New patches in v6:

[PATCH v6 14/16] media: cadence: csi2rx: Support runtime PM
[PATCH v6 15/16] media: ti: j721e-csi2rx: Support runtime suspend
[PATCH v6 16/16] media: ti: j721e-csi2rx: Support system suspend
using pm_notifier

# Changes in patches from v5:
[PATCH v5 01/16] media: ti: j721e-csi2rx: Remove word size alignment
on frame width
- Remove restrictions on minimum frame width in ti_csi2rx_fill_fmt()
- Add Reviewed-by from Abhilash
[PATCH v5 02/16] dt-bindings: media: ti,j721e-csi2rx-shim: Support 32 dma chans
- No change
[PATCH v5 03/16] media: ti: j721e-csi2rx: separate out device and context
- No change
[PATCH v5 04/16] media: ti: j721e-csi2rx: prepare SHIM code for multiple contexts
- No change
[PATCH v5 05/16] media: ti: j721e-csi2rx: allocate DMA channel based on context index
- No change
[PATCH v5 06/16] media: ti: j721e-csi2rx: add a subdev for the core device
- No change
[PATCH v5 07/16] media: ti: j721e-csi2rx: get number of contexts from device tree
- Solve compilation warnings
[PATCH v5 08/16] media: cadence: csi2rx: add get_frame_desc wrapper
- No change
[PATCH v5 09/16] media: ti: j721e-csi2rx: add support for processing virtual channels
- Remove unnecessary call to v4l2_unlock_state()
[PATCH v5 10/16] media: cadence: csi2rx: add multistream support
- No change
[PATCH v5 11/16] media: ti: j721e-csi2rx: add multistream support
- No change
[PATCH v5 12/16] media: ti: j721e-csi2rx: Submit all available buffers
- No change
[PATCH v5 13/16] media: ti: j721e-csi2rx: Change the drain architecture for multistream
- Squash implementation of completion barriers for last drain cycle
- Make struct completion per ctx

Link to (v5):
https://lore.kernel.org/all/20250825142522.1826188-1-r-donadkar@ti.com/

---
Changes in v5:

# New patches in v5:

[PATCH v5 01/14] media: ti: j721e-csi2rx: Remove word size alignment
[PATCH v5 14/14] media: ti: j721e-csi2rx: Wait for the last drain

# Changes in patches from v4:

[PATCH v4 01/12] dt-bindings: media: ti,j721e-csi2rx-shim: Support 32 dma chans
- No change
[PATCH v4 02/12] media: ti: j721e-csi2rx: separate out device and context
- No change
[PATCH v4 03/12] media: ti: j721e-csi2rx: prepare SHIM code for multiple contexts
- No change
[PATCH v4 04/12] media: ti: j721e-csi2rx: allocate DMA channel based on context index
- No change
[PATCH v4 05/12] media: ti: j721e-csi2rx: add a subdev for the core device
- No change
[PATCH v4 06/12] media: ti: j721e-csi2rx: get number of contexts from device tree
- No change
[PATCH v4 07/12] media: cadence: csi2rx: add get_frame_desc wrapper
- No change
[PATCH v4 08/12] media: ti: j721e-csi2rx: add support for processing virtual channels
- No change
[PATCH v4 09/12] media: cadence: csi2rx: add multistream support
- No change
[PATCH v4 10/12] media: ti: j721e-csi2rx: add multistream support
- Serialize stream stop
- Remove the break statement to avoid early return in the loop, as
  reported by Sjoerd
[PATCH v4 11/12] media: ti: j721e-csi2rx: Submit all available buffers
- Delete the list node on DMA error to avoid kernel panic
[PATCH v4 12/12] media: ti: j721e-csi2rx: Change the drain architecture for multistream
- Mention about next frame after drain being bogus

Link to (v4):
  https://lore.kernel.org/all/20250514112527.1983068-1-r-donadkar@ti.com/

Changes in v4:

[PATCH 01/13] dt-bindings: media: ti,j721e-csi2rx-shim: Support 32 dma chans
  - No change
[PATCH 02/13] media: ti: j721e-csi2rx: separate out device and context
  - Add ctx identifier in the dev_err() message
  - No change
[PATCH 03/13] media: ti: j721e-csi2rx: prepare SHIM code for multiple contexts
  - Reduced the name string lenght from 32 chars to 5 chars
[PATCH 04/13] media: ti: j721e-csi2rx: allocate DMA channel based on context index
  - No change
[PATCH 05/13] media: ti: j721e-csi2rx: add a subdev for the core device
  - Add .enum_mbus_code callback
  - Replace statically allocated struct with a global static const struct
    v4l2_mbus_framefmt and used that in the _init_state() function
[PATCH 06/13] media: ti: j721e-csi2rx: get number of contexts from device tree
  - Fix the drain buffer being leaked
  - If the shows more number of ctx than the TI_CSI2RX_MAX_CTX, return an error
    instead of warning
[PATCH 07/13] media: cadence: csi2rx: add get_frame_desc wrapper
  - No change
[PATCH 08/13] media: ti: j721e-csi2rx: add support for processing virtual channels
  - Call ti_csi2rx_get_vc() only once on first stream start and cache the VC data in
    the driver, use the corresponding VC in all subsequent stream starts.
[PATCH 09/13] media: cadence: csi2rx: Use new enable stream APIs
[PATCH 10/13] media: cadence: csi2rx: Enable multi-stream support
  - Squash the above two patches into
    [PATCH v4 09/12] media: cadence: csi2rx: add multistream support
  - Use already obtained csi2rx->source_pad in enable_streams() and
    disable_streams() call
  - Update commit message with the reason for using a custom helper for s_stream
    instead of v4l2_subdev_s_stream_helper()
  - Use v4l2_get_link_freq() variant that takes pad of the source as its first
    argument instead of the one that takes v4l2_ctrl_handler
  - Call v4l2_get_link_freq() with bpp = 0 to prevent fallback to V4L2_CID_PIXEL_RATE
    in multi-stream case
  - Use lock guards to simplify error handling
  - Call csi2rx_update_vc_select() at first stream start before enabling the controller
[PATCH 11/13] media: ti: j721e-csi2rx: add multistream support
  - No change
[PATCH 12/13] media: ti: j721e-csi2rx: Submit all available buffers
  - No change
[PATCH 13/13] media: ti: j721e-csi2rx: Change the drain architecture for multistream
  - Fix checkpatch warning
  - Change commit message to give a better description of the patch

Link to (v3):
  https://lore.kernel.org/all/20250417065554.437541-1-r-donadkar@ti.com/

Changes in v3:

- Drop [PATCH v2 01/13] media: cadence: csi2rx: Support runtime PM from
  v2, support for runtime PM will be added in a separate series:
  https://lore.kernel.org/all/20250224-ti_csi_pm-v1-0-8f8c29ef646d@ideasonboard.com/
- Change the drain architecture to prevent FIFO overflow in multistream
  usecases.
- With the new drain architecture, we don't need the the driver to wait
  for userspace to start streaming on all "actively routed" video nodes
  before starting streaming on the source. So, revert back to the capture
  architecture where streams can be started and stopped independent
  to each other.

Link to (v2):
  https://lore.kernel.org/r/20240627-multistream-v2-0-6ae96c54c1c3@ti.com

Changes in v2:

- Change the multi-camera capture architecture to be similar to that of
  Tomi's RPi5 FE series, where the driver will wait for userspace to
  start streaming on all "actively routed" video nodes before starting
  streaming on the source. This simplifies things a lot from the HW
  perspective, which might run into deadlocks due to a shared FIFO
  between multiple DMA channels.

- Drop a few fixes that were posted separately and are already merged
- Fix dtschema warnings reported by Rob on [02/13]
- Fix warnings for uninitialized `used_vc` variable in cdns-csi2rx.c
- Return -EBUSY if someone updates routes for j721e-csi2rx subdev while
  streaming
- Only allow single-streams to be routed to the source pads (linked to
  video nodes) of the j721e-csi2rx device
- Squash the patches marked "SQUASH" in the v1 RFC series


Changhuang Liang (1):
  media: cadence: csi2rx: Support runtime PM

Jai Luthra (9):
  dt-bindings: media: ti,j721e-csi2rx-shim: Support 32 dma chans
  media: ti: j721e-csi2rx: separate out device and context
  media: ti: j721e-csi2rx: add a subdev for the core device
  media: ti: j721e-csi2rx: add support for processing virtual channels
  media: cadence: csi2rx: add multistream support
  media: ti: j721e-csi2rx: add multistream support
  media: ti: j721e-csi2rx: Submit all available buffers
  media: ti: j721e-csi2rx: Support runtime suspend
  media: ti: j721e-csi2rx: Support system suspend using pm_notifier

Pratyush Yadav (4):
  media: ti: j721e-csi2rx: prepare SHIM code for multiple contexts
  media: ti: j721e-csi2rx: allocate DMA channel based on context index
  media: ti: j721e-csi2rx: get number of contexts from device tree
  media: cadence: csi2rx: add get_frame_desc wrapper

Rishikesh Donadkar (4):
  media: ti: j721e-csi2rx: Remove word size alignment on frame width
  media: cadence: csi2rx: Move to .enable/disable_streams API
  media: ti: j721e-csi2rx: Move to .enable/disable_streams API
  media: ti: j721e-csi2rx: Change the drain architecture for multistream

 .../bindings/media/ti,j721e-csi2rx-shim.yaml  |   39 +-
 drivers/media/platform/cadence/Kconfig        |    1 +
 drivers/media/platform/cadence/cdns-csi2rx.c  |  496 +++++--
 drivers/media/platform/ti/Kconfig             |    1 +
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 1186 +++++++++++++----
 5 files changed, 1304 insertions(+), 419 deletions(-)

-- 
2.34.1

[PATCH v8 01/18] media: ti: j721e-csi2rx: Remove word size alignment on frame width

[Rishikesh Donadkar]

j721e-csi2rx driver has a limitation of frame width being a multiple
word size. However, there is no such limitation imposed by the
hardware [1].

Remove this limitation from the driver.

Link: https://www.ti.com/lit/pdf/spruj16
Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 24 ++++---------------
 1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index b75aa363d1bf2..710d05a053539 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -43,7 +43,6 @@
 #define SHIM_PSI_CFG0_DST_TAG		GENMASK(31, 16)
 
 #define TI_CSI2RX_MAX_PIX_PER_CLK	4
-#define PSIL_WORD_SIZE_BYTES		16
 /*
  * There are no hard limits on the width or height. The DMA engine can handle
  * all sizes. The max width and height are arbitrary numbers for this driver.
@@ -250,19 +249,12 @@ static void ti_csi2rx_fill_fmt(const struct ti_csi2rx_fmt *csi_fmt,
 			       struct v4l2_format *v4l2_fmt)
 {
 	struct v4l2_pix_format *pix = &v4l2_fmt->fmt.pix;
-	unsigned int pixels_in_word;
-
-	pixels_in_word = PSIL_WORD_SIZE_BYTES * 8 / csi_fmt->bpp;
 
 	/* Clamp width and height to sensible maximums (16K x 16K) */
 	pix->width = clamp_t(unsigned int, pix->width,
-			     pixels_in_word,
-			     MAX_WIDTH_BYTES * 8 / csi_fmt->bpp);
+			     1, MAX_WIDTH_BYTES * 8 / csi_fmt->bpp);
 	pix->height = clamp_t(unsigned int, pix->height, 1, MAX_HEIGHT_LINES);
 
-	/* Width should be a multiple of transfer word-size */
-	pix->width = rounddown(pix->width, pixels_in_word);
-
 	v4l2_fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 	pix->pixelformat = csi_fmt->fourcc;
 	pix->bytesperline = pix->width * (csi_fmt->bpp / 8);
@@ -360,23 +352,15 @@ static int ti_csi2rx_enum_framesizes(struct file *file, void *fh,
 				     struct v4l2_frmsizeenum *fsize)
 {
 	const struct ti_csi2rx_fmt *fmt;
-	unsigned int pixels_in_word;
 
 	fmt = find_format_by_fourcc(fsize->pixel_format);
 	if (!fmt || fsize->index != 0)
 		return -EINVAL;
 
-	/*
-	 * Number of pixels in one PSI-L word. The transfer happens in multiples
-	 * of PSI-L word sizes.
-	 */
-	pixels_in_word = PSIL_WORD_SIZE_BYTES * 8 / fmt->bpp;
-
 	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
-	fsize->stepwise.min_width = pixels_in_word;
-	fsize->stepwise.max_width = rounddown(MAX_WIDTH_BYTES * 8 / fmt->bpp,
-					      pixels_in_word);
-	fsize->stepwise.step_width = pixels_in_word;
+	fsize->stepwise.min_width = 1;
+	fsize->stepwise.max_width = MAX_WIDTH_BYTES * 8 / fmt->bpp;
+	fsize->stepwise.step_width = 1;
 	fsize->stepwise.min_height = 1;
 	fsize->stepwise.max_height = MAX_HEIGHT_LINES;
 	fsize->stepwise.step_height = 1;
-- 
2.34.1

[PATCH v8 02/18] dt-bindings: media: ti,j721e-csi2rx-shim: Support 32 dma chans

[Rishikesh Donadkar]

From: Jai Luthra <j-luthra@ti.com>

The CSI2RX SHIM IP can support 32x DMA channels. These can be used to
split incoming "streams" of data on the CSI-RX port, distinguished by
MIPI Virtual Channel (or Data Type), into different locations in memory.

Actual number of DMA channels allocated to CSI-RX is dependent on the
usecase, and can be modified using the K3 Resource Partitioning tool [1].
So set the minimum channels as 1 and maximum as 32.

Link: https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/10_00_07_04/exports/docs/linux/How_to_Guides/Host/K3_Resource_Partitioning_Tool.html [1]
Link: https://www.ti.com/lit/pdf/spruiv7
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../bindings/media/ti,j721e-csi2rx-shim.yaml  | 39 +++++++++++++++++--
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/media/ti,j721e-csi2rx-shim.yaml b/Documentation/devicetree/bindings/media/ti,j721e-csi2rx-shim.yaml
index b9f033f2f3ce4..bf62998b0445a 100644
--- a/Documentation/devicetree/bindings/media/ti,j721e-csi2rx-shim.yaml
+++ b/Documentation/devicetree/bindings/media/ti,j721e-csi2rx-shim.yaml
@@ -20,11 +20,44 @@ properties:
     const: ti,j721e-csi2rx-shim
 
   dmas:
-    maxItems: 1
+    minItems: 1
+    maxItems: 32
 
   dma-names:
+    minItems: 1
     items:
       - const: rx0
+      - const: rx1
+      - const: rx2
+      - const: rx3
+      - const: rx4
+      - const: rx5
+      - const: rx6
+      - const: rx7
+      - const: rx8
+      - const: rx9
+      - const: rx10
+      - const: rx11
+      - const: rx12
+      - const: rx13
+      - const: rx14
+      - const: rx15
+      - const: rx16
+      - const: rx17
+      - const: rx18
+      - const: rx19
+      - const: rx20
+      - const: rx21
+      - const: rx22
+      - const: rx23
+      - const: rx24
+      - const: rx25
+      - const: rx26
+      - const: rx27
+      - const: rx28
+      - const: rx29
+      - const: rx30
+      - const: rx31
 
   reg:
     maxItems: 1
@@ -62,8 +95,8 @@ examples:
 
     ti_csi2rx0: ticsi2rx@4500000 {
         compatible = "ti,j721e-csi2rx-shim";
-        dmas = <&main_udmap 0x4940>;
-        dma-names = "rx0";
+        dmas = <&main_udmap 0x4940>, <&main_udmap 0x4941>;
+        dma-names = "rx0", "rx1";
         reg = <0x4500000 0x1000>;
         power-domains = <&k3_pds 26 TI_SCI_PD_EXCLUSIVE>;
         #address-cells = <1>;
-- 
2.34.1

[PATCH v8 03/18] media: ti: j721e-csi2rx: separate out device and context

[Rishikesh Donadkar]

From: Jai Luthra <j-luthra@ti.com>

The TI CSI2RX wrapper has two parts: the main device and the DMA
contexts. The driver was originally written with single camera capture
in mind, so only one DMA context was needed. For the sake of simplicity,
the context specific stuff was not modeled different to the main device.

To enable multiplexed stream capture, the contexts need to be separated
out from the main device. Create a struct ti_csi2rx_ctx that holds the
DMA context specific things. Separate out functions handling the device
and context related functionality.

Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 423 ++++++++++--------
 1 file changed, 234 insertions(+), 189 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 710d05a053539..23717a3b6c4cf 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -43,6 +43,8 @@
 #define SHIM_PSI_CFG0_DST_TAG		GENMASK(31, 16)
 
 #define TI_CSI2RX_MAX_PIX_PER_CLK	4
+#define TI_CSI2RX_NUM_CTX		1
+
 /*
  * There are no hard limits on the width or height. The DMA engine can handle
  * all sizes. The max width and height are arbitrary numbers for this driver.
@@ -69,7 +71,7 @@ struct ti_csi2rx_buffer {
 	/* Common v4l2 buffer. Must be first. */
 	struct vb2_v4l2_buffer		vb;
 	struct list_head		list;
-	struct ti_csi2rx_dev		*csi;
+	struct ti_csi2rx_ctx		*ctx;
 };
 
 enum ti_csi2rx_dma_state {
@@ -89,30 +91,38 @@ struct ti_csi2rx_dma {
 	 * Queue of buffers submitted to DMA engine.
 	 */
 	struct list_head		submitted;
-	/* Buffer to drain stale data from PSI-L endpoint */
-	struct {
-		void			*vaddr;
-		dma_addr_t		paddr;
-		size_t			len;
-	} drain;
+};
+
+struct ti_csi2rx_dev;
+
+struct ti_csi2rx_ctx {
+	struct ti_csi2rx_dev		*csi;
+	struct video_device		vdev;
+	struct vb2_queue		vidq;
+	struct mutex			mutex; /* To serialize ioctls. */
+	struct v4l2_format		v_fmt;
+	struct ti_csi2rx_dma		dma;
+	u32				sequence;
+	u32				idx;
 };
 
 struct ti_csi2rx_dev {
 	struct device			*dev;
 	void __iomem			*shim;
 	struct v4l2_device		v4l2_dev;
-	struct video_device		vdev;
 	struct media_device		mdev;
 	struct media_pipeline		pipe;
 	struct media_pad		pad;
 	struct v4l2_async_notifier	notifier;
 	struct v4l2_subdev		*source;
-	struct vb2_queue		vidq;
-	struct mutex			mutex; /* To serialize ioctls. */
-	struct v4l2_format		v_fmt;
-	struct ti_csi2rx_dma		dma;
-	u32				sequence;
+	struct ti_csi2rx_ctx		ctx[TI_CSI2RX_NUM_CTX];
 	u8				pix_per_clk;
+	/* Buffer to drain stale data from PSI-L endpoint */
+	struct {
+		void			*vaddr;
+		dma_addr_t		paddr;
+		size_t			len;
+	} drain;
 };
 
 static const struct ti_csi2rx_fmt ti_csi2rx_formats[] = {
@@ -218,7 +228,7 @@ static const struct ti_csi2rx_fmt ti_csi2rx_formats[] = {
 };
 
 /* Forward declaration needed by ti_csi2rx_dma_callback. */
-static int ti_csi2rx_start_dma(struct ti_csi2rx_dev *csi,
+static int ti_csi2rx_start_dma(struct ti_csi2rx_ctx *ctx,
 			       struct ti_csi2rx_buffer *buf);
 
 static const struct ti_csi2rx_fmt *find_format_by_fourcc(u32 pixelformat)
@@ -301,7 +311,7 @@ static int ti_csi2rx_enum_fmt_vid_cap(struct file *file, void *priv,
 static int ti_csi2rx_g_fmt_vid_cap(struct file *file, void *priv,
 				   struct v4l2_format *f)
 {
-	struct ti_csi2rx_dev *csi = video_drvdata(file);
+	struct ti_csi2rx_ctx *csi = video_drvdata(file);
 
 	*f = csi->v_fmt;
 
@@ -332,7 +342,7 @@ static int ti_csi2rx_try_fmt_vid_cap(struct file *file, void *priv,
 static int ti_csi2rx_s_fmt_vid_cap(struct file *file, void *priv,
 				   struct v4l2_format *f)
 {
-	struct ti_csi2rx_dev *csi = video_drvdata(file);
+	struct ti_csi2rx_ctx *csi = video_drvdata(file);
 	struct vb2_queue *q = &csi->vidq;
 	int ret;
 
@@ -410,26 +420,35 @@ static int csi_async_notifier_bound(struct v4l2_async_notifier *notifier,
 static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
 {
 	struct ti_csi2rx_dev *csi = dev_get_drvdata(notifier->v4l2_dev->dev);
-	struct video_device *vdev = &csi->vdev;
-	int ret;
+	int ret, i;
 
-	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
-	if (ret)
-		return ret;
-
-	ret = media_create_pad_link(&csi->source->entity, CSI2RX_BRIDGE_SOURCE_PAD,
-				    &vdev->entity, csi->pad.index,
-				    MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
+	for (i = 0; i < TI_CSI2RX_NUM_CTX; i++) {
+		struct ti_csi2rx_ctx *ctx = &csi->ctx[i];
+		struct video_device *vdev = &ctx->vdev;
 
-	if (ret) {
-		video_unregister_device(vdev);
-		return ret;
+		ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
+		if (ret)
+			goto unregister_dev;
 	}
 
+	ret = media_create_pad_link(&csi->source->entity,
+				    CSI2RX_BRIDGE_SOURCE_PAD,
+				    &csi->ctx[0].vdev.entity, csi->pad.index,
+				    MEDIA_LNK_FL_IMMUTABLE |
+				    MEDIA_LNK_FL_ENABLED);
+	if (ret)
+		goto unregister_dev;
+
 	ret = v4l2_device_register_subdev_nodes(&csi->v4l2_dev);
 	if (ret)
-		video_unregister_device(vdev);
+		goto unregister_dev;
 
+	return 0;
+
+unregister_dev:
+	i--;
+	for (; i >= 0; i--)
+		video_unregister_device(&csi->ctx[i].vdev);
 	return ret;
 }
 
@@ -474,13 +493,14 @@ static int ti_csi2rx_notifier_register(struct ti_csi2rx_dev *csi)
 }
 
 /* Request maximum possible pixels per clock from the bridge */
-static void ti_csi2rx_request_max_ppc(struct ti_csi2rx_dev *csi)
+static void ti_csi2rx_request_max_ppc(struct ti_csi2rx_ctx *ctx)
 {
+	struct ti_csi2rx_dev *csi = ctx->csi;
 	u8 ppc = TI_CSI2RX_MAX_PIX_PER_CLK;
 	struct media_pad *pad;
 	int ret;
 
-	pad = media_entity_remote_source_pad_unique(&csi->vdev.entity);
+	pad = media_entity_remote_source_pad_unique(&ctx->vdev.entity);
 	if (IS_ERR(pad))
 		return;
 
@@ -493,19 +513,20 @@ static void ti_csi2rx_request_max_ppc(struct ti_csi2rx_dev *csi)
 	}
 }
 
-static void ti_csi2rx_setup_shim(struct ti_csi2rx_dev *csi)
+static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
 {
+	struct ti_csi2rx_dev *csi = ctx->csi;
 	const struct ti_csi2rx_fmt *fmt;
 	unsigned int reg;
 
-	fmt = find_format_by_fourcc(csi->v_fmt.fmt.pix.pixelformat);
+	fmt = find_format_by_fourcc(ctx->v_fmt.fmt.pix.pixelformat);
 
 	/* De-assert the pixel interface reset. */
 	reg = SHIM_CNTL_PIX_RST;
 	writel(reg, csi->shim + SHIM_CNTL);
 
 	/* Negotiate pixel count from the source */
-	ti_csi2rx_request_max_ppc(csi);
+	ti_csi2rx_request_max_ppc(ctx);
 
 	reg = SHIM_DMACNTX_EN;
 	reg |= FIELD_PREP(SHIM_DMACNTX_FMT, fmt->csi_dt);
@@ -572,8 +593,9 @@ static void ti_csi2rx_drain_callback(void *param)
  * To prevent that stale data corrupting the subsequent transactions, it is
  * required to issue DMA requests to drain it out.
  */
-static int ti_csi2rx_drain_dma(struct ti_csi2rx_dev *csi)
+static int ti_csi2rx_drain_dma(struct ti_csi2rx_ctx *ctx)
 {
+	struct ti_csi2rx_dev *csi = ctx->csi;
 	struct dma_async_tx_descriptor *desc;
 	struct completion drain_complete;
 	dma_cookie_t cookie;
@@ -581,8 +603,8 @@ static int ti_csi2rx_drain_dma(struct ti_csi2rx_dev *csi)
 
 	init_completion(&drain_complete);
 
-	desc = dmaengine_prep_slave_single(csi->dma.chan, csi->dma.drain.paddr,
-					   csi->dma.drain.len, DMA_DEV_TO_MEM,
+	desc = dmaengine_prep_slave_single(ctx->dma.chan, csi->drain.paddr,
+					   csi->drain.len, DMA_DEV_TO_MEM,
 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
 		ret = -EIO;
@@ -597,11 +619,11 @@ static int ti_csi2rx_drain_dma(struct ti_csi2rx_dev *csi)
 	if (ret)
 		goto out;
 
-	dma_async_issue_pending(csi->dma.chan);
+	dma_async_issue_pending(ctx->dma.chan);
 
 	if (!wait_for_completion_timeout(&drain_complete,
 					 msecs_to_jiffies(DRAIN_TIMEOUT_MS))) {
-		dmaengine_terminate_sync(csi->dma.chan);
+		dmaengine_terminate_sync(ctx->dma.chan);
 		dev_dbg(csi->dev, "DMA transfer timed out for drain buffer\n");
 		ret = -ETIMEDOUT;
 		goto out;
@@ -613,8 +635,9 @@ static int ti_csi2rx_drain_dma(struct ti_csi2rx_dev *csi)
 static void ti_csi2rx_dma_callback(void *param)
 {
 	struct ti_csi2rx_buffer *buf = param;
-	struct ti_csi2rx_dev *csi = buf->csi;
-	struct ti_csi2rx_dma *dma = &csi->dma;
+	struct ti_csi2rx_ctx *ctx = buf->ctx;
+	struct ti_csi2rx_dev *csi = ctx->csi;
+	struct ti_csi2rx_dma *dma = &ctx->dma;
 	unsigned long flags;
 
 	/*
@@ -622,7 +645,7 @@ static void ti_csi2rx_dma_callback(void *param)
 	 * hardware monitor registers.
 	 */
 	buf->vb.vb2_buf.timestamp = ktime_get_ns();
-	buf->vb.sequence = csi->sequence++;
+	buf->vb.sequence = ctx->sequence++;
 
 	spin_lock_irqsave(&dma->lock, flags);
 
@@ -634,7 +657,7 @@ static void ti_csi2rx_dma_callback(void *param)
 	while (!list_empty(&dma->queue)) {
 		buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
 
-		if (ti_csi2rx_start_dma(csi, buf)) {
+		if (ti_csi2rx_start_dma(ctx, buf)) {
 			dev_err(csi->dev, "Failed to queue the next buffer for DMA\n");
 			list_del(&buf->list);
 			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
@@ -649,17 +672,17 @@ static void ti_csi2rx_dma_callback(void *param)
 	spin_unlock_irqrestore(&dma->lock, flags);
 }
 
-static int ti_csi2rx_start_dma(struct ti_csi2rx_dev *csi,
+static int ti_csi2rx_start_dma(struct ti_csi2rx_ctx *ctx,
 			       struct ti_csi2rx_buffer *buf)
 {
 	unsigned long addr;
 	struct dma_async_tx_descriptor *desc;
-	size_t len = csi->v_fmt.fmt.pix.sizeimage;
+	size_t len = ctx->v_fmt.fmt.pix.sizeimage;
 	dma_cookie_t cookie;
 	int ret = 0;
 
 	addr = vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
-	desc = dmaengine_prep_slave_single(csi->dma.chan, addr, len,
+	desc = dmaengine_prep_slave_single(ctx->dma.chan, addr, len,
 					   DMA_DEV_TO_MEM,
 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc)
@@ -673,20 +696,20 @@ static int ti_csi2rx_start_dma(struct ti_csi2rx_dev *csi,
 	if (ret)
 		return ret;
 
-	dma_async_issue_pending(csi->dma.chan);
+	dma_async_issue_pending(ctx->dma.chan);
 
 	return 0;
 }
 
-static void ti_csi2rx_stop_dma(struct ti_csi2rx_dev *csi)
+static void ti_csi2rx_stop_dma(struct ti_csi2rx_ctx *ctx)
 {
-	struct ti_csi2rx_dma *dma = &csi->dma;
+	struct ti_csi2rx_dma *dma = &ctx->dma;
 	enum ti_csi2rx_dma_state state;
 	unsigned long flags;
 	int ret;
 
 	spin_lock_irqsave(&dma->lock, flags);
-	state = csi->dma.state;
+	state = ctx->dma.state;
 	dma->state = TI_CSI2RX_DMA_STOPPED;
 	spin_unlock_irqrestore(&dma->lock, flags);
 
@@ -697,30 +720,30 @@ static void ti_csi2rx_stop_dma(struct ti_csi2rx_dev *csi)
 		 * is stopped, as the module-level pixel reset cannot be
 		 * enforced before terminating DMA.
 		 */
-		ret = ti_csi2rx_drain_dma(csi);
+		ret = ti_csi2rx_drain_dma(ctx);
 		if (ret && ret != -ETIMEDOUT)
-			dev_warn(csi->dev,
+			dev_warn(ctx->csi->dev,
 				 "Failed to drain DMA. Next frame might be bogus\n");
 	}
 
-	ret = dmaengine_terminate_sync(csi->dma.chan);
+	ret = dmaengine_terminate_sync(ctx->dma.chan);
 	if (ret)
-		dev_err(csi->dev, "Failed to stop DMA: %d\n", ret);
+		dev_err(ctx->csi->dev, "Failed to stop DMA: %d\n", ret);
 }
 
-static void ti_csi2rx_cleanup_buffers(struct ti_csi2rx_dev *csi,
+static void ti_csi2rx_cleanup_buffers(struct ti_csi2rx_ctx *ctx,
 				      enum vb2_buffer_state state)
 {
-	struct ti_csi2rx_dma *dma = &csi->dma;
+	struct ti_csi2rx_dma *dma = &ctx->dma;
 	struct ti_csi2rx_buffer *buf, *tmp;
 	unsigned long flags;
 
 	spin_lock_irqsave(&dma->lock, flags);
-	list_for_each_entry_safe(buf, tmp, &csi->dma.queue, list) {
+	list_for_each_entry_safe(buf, tmp, &ctx->dma.queue, list) {
 		list_del(&buf->list);
 		vb2_buffer_done(&buf->vb.vb2_buf, state);
 	}
-	list_for_each_entry_safe(buf, tmp, &csi->dma.submitted, list) {
+	list_for_each_entry_safe(buf, tmp, &ctx->dma.submitted, list) {
 		list_del(&buf->list);
 		vb2_buffer_done(&buf->vb.vb2_buf, state);
 	}
@@ -731,8 +754,8 @@ static int ti_csi2rx_queue_setup(struct vb2_queue *q, unsigned int *nbuffers,
 				 unsigned int *nplanes, unsigned int sizes[],
 				 struct device *alloc_devs[])
 {
-	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(q);
-	unsigned int size = csi->v_fmt.fmt.pix.sizeimage;
+	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(q);
+	unsigned int size = ctx->v_fmt.fmt.pix.sizeimage;
 
 	if (*nplanes) {
 		if (sizes[0] < size)
@@ -748,11 +771,11 @@ static int ti_csi2rx_queue_setup(struct vb2_queue *q, unsigned int *nbuffers,
 
 static int ti_csi2rx_buffer_prepare(struct vb2_buffer *vb)
 {
-	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(vb->vb2_queue);
-	unsigned long size = csi->v_fmt.fmt.pix.sizeimage;
+	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned long size = ctx->v_fmt.fmt.pix.sizeimage;
 
 	if (vb2_plane_size(vb, 0) < size) {
-		dev_err(csi->dev, "Data will not fit into plane\n");
+		dev_err(ctx->csi->dev, "Data will not fit into plane\n");
 		return -EINVAL;
 	}
 
@@ -762,15 +785,15 @@ static int ti_csi2rx_buffer_prepare(struct vb2_buffer *vb)
 
 static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
 {
-	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(vb->vb2_queue);
+	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
 	struct ti_csi2rx_buffer *buf;
-	struct ti_csi2rx_dma *dma = &csi->dma;
+	struct ti_csi2rx_dma *dma = &ctx->dma;
 	bool restart_dma = false;
 	unsigned long flags = 0;
 	int ret;
 
 	buf = container_of(vb, struct ti_csi2rx_buffer, vb.vb2_buf);
-	buf->csi = csi;
+	buf->ctx = ctx;
 
 	spin_lock_irqsave(&dma->lock, flags);
 	/*
@@ -799,18 +822,18 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
 		 * the application and will only confuse it. Issue a DMA
 		 * transaction to drain that up.
 		 */
-		ret = ti_csi2rx_drain_dma(csi);
+		ret = ti_csi2rx_drain_dma(ctx);
 		if (ret && ret != -ETIMEDOUT)
-			dev_warn(csi->dev,
+			dev_warn(ctx->csi->dev,
 				 "Failed to drain DMA. Next frame might be bogus\n");
 
 		spin_lock_irqsave(&dma->lock, flags);
-		ret = ti_csi2rx_start_dma(csi, buf);
+		ret = ti_csi2rx_start_dma(ctx, buf);
 		if (ret) {
 			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 			dma->state = TI_CSI2RX_DMA_IDLE;
 			spin_unlock_irqrestore(&dma->lock, flags);
-			dev_err(csi->dev, "Failed to start DMA: %d\n", ret);
+			dev_err(ctx->csi->dev, "Failed to start DMA: %d\n", ret);
 		} else {
 			list_add_tail(&buf->list, &dma->submitted);
 			spin_unlock_irqrestore(&dma->lock, flags);
@@ -820,8 +843,9 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
 
 static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 {
-	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(vq);
-	struct ti_csi2rx_dma *dma = &csi->dma;
+	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
+	struct ti_csi2rx_dev *csi = ctx->csi;
+	struct ti_csi2rx_dma *dma = &ctx->dma;
 	struct ti_csi2rx_buffer *buf;
 	unsigned long flags;
 	int ret = 0;
@@ -833,18 +857,18 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	if (ret)
 		return ret;
 
-	ret = video_device_pipeline_start(&csi->vdev, &csi->pipe);
+	ret = video_device_pipeline_start(&ctx->vdev, &csi->pipe);
 	if (ret)
 		goto err;
 
-	ti_csi2rx_setup_shim(csi);
+	ti_csi2rx_setup_shim(ctx);
 
-	csi->sequence = 0;
+	ctx->sequence = 0;
 
 	spin_lock_irqsave(&dma->lock, flags);
 	buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
 
-	ret = ti_csi2rx_start_dma(csi, buf);
+	ret = ti_csi2rx_start_dma(ctx, buf);
 	if (ret) {
 		dev_err(csi->dev, "Failed to start DMA: %d\n", ret);
 		spin_unlock_irqrestore(&dma->lock, flags);
@@ -862,22 +886,23 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return 0;
 
 err_dma:
-	ti_csi2rx_stop_dma(csi);
+	ti_csi2rx_stop_dma(ctx);
 err_pipeline:
-	video_device_pipeline_stop(&csi->vdev);
+	video_device_pipeline_stop(&ctx->vdev);
 	writel(0, csi->shim + SHIM_CNTL);
 	writel(0, csi->shim + SHIM_DMACNTX);
 err:
-	ti_csi2rx_cleanup_buffers(csi, VB2_BUF_STATE_QUEUED);
+	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
 	return ret;
 }
 
 static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 {
-	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(vq);
+	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
+	struct ti_csi2rx_dev *csi = ctx->csi;
 	int ret;
 
-	video_device_pipeline_stop(&csi->vdev);
+	video_device_pipeline_stop(&ctx->vdev);
 
 	writel(0, csi->shim + SHIM_CNTL);
 	writel(0, csi->shim + SHIM_DMACNTX);
@@ -886,8 +911,8 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 	if (ret)
 		dev_err(csi->dev, "Failed to stop subdev stream\n");
 
-	ti_csi2rx_stop_dma(csi);
-	ti_csi2rx_cleanup_buffers(csi, VB2_BUF_STATE_ERROR);
+	ti_csi2rx_stop_dma(ctx);
+	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
 }
 
 static const struct vb2_ops csi_vb2_qops = {
@@ -898,20 +923,43 @@ static const struct vb2_ops csi_vb2_qops = {
 	.stop_streaming = ti_csi2rx_stop_streaming,
 };
 
-static int ti_csi2rx_init_vb2q(struct ti_csi2rx_dev *csi)
+static void ti_csi2rx_cleanup_v4l2(struct ti_csi2rx_dev *csi)
 {
-	struct vb2_queue *q = &csi->vidq;
+	media_device_unregister(&csi->mdev);
+	v4l2_device_unregister(&csi->v4l2_dev);
+	media_device_cleanup(&csi->mdev);
+}
+
+static void ti_csi2rx_cleanup_notifier(struct ti_csi2rx_dev *csi)
+{
+	v4l2_async_nf_unregister(&csi->notifier);
+	v4l2_async_nf_cleanup(&csi->notifier);
+}
+
+static void ti_csi2rx_cleanup_ctx(struct ti_csi2rx_ctx *ctx)
+{
+	dma_release_channel(ctx->dma.chan);
+	vb2_queue_release(&ctx->vidq);
+
+	video_unregister_device(&ctx->vdev);
+
+	mutex_destroy(&ctx->mutex);
+}
+
+static int ti_csi2rx_init_vb2q(struct ti_csi2rx_ctx *ctx)
+{
+	struct vb2_queue *q = &ctx->vidq;
 	int ret;
 
 	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 	q->io_modes = VB2_MMAP | VB2_DMABUF;
-	q->drv_priv = csi;
+	q->drv_priv = ctx;
 	q->buf_struct_size = sizeof(struct ti_csi2rx_buffer);
 	q->ops = &csi_vb2_qops;
 	q->mem_ops = &vb2_dma_contig_memops;
 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
-	q->dev = dmaengine_get_dma_device(csi->dma.chan);
-	q->lock = &csi->mutex;
+	q->dev = dmaengine_get_dma_device(ctx->dma.chan);
+	q->lock = &ctx->mutex;
 	q->min_queued_buffers = 1;
 	q->allow_cache_hints = 1;
 
@@ -919,7 +967,7 @@ static int ti_csi2rx_init_vb2q(struct ti_csi2rx_dev *csi)
 	if (ret)
 		return ret;
 
-	csi->vdev.queue = q;
+	ctx->vdev.queue = q;
 
 	return 0;
 }
@@ -928,8 +976,9 @@ static int ti_csi2rx_link_validate(struct media_link *link)
 {
 	struct media_entity *entity = link->sink->entity;
 	struct video_device *vdev = media_entity_to_video_device(entity);
-	struct ti_csi2rx_dev *csi = container_of(vdev, struct ti_csi2rx_dev, vdev);
-	struct v4l2_pix_format *csi_fmt = &csi->v_fmt.fmt.pix;
+	struct ti_csi2rx_ctx *ctx = container_of(vdev, struct ti_csi2rx_ctx, vdev);
+	struct ti_csi2rx_dev *csi = ctx->csi;
+	struct v4l2_pix_format *csi_fmt = &ctx->v_fmt.fmt.pix;
 	struct v4l2_subdev_format source_fmt = {
 		.which	= V4L2_SUBDEV_FORMAT_ACTIVE,
 		.pad	= link->source->index,
@@ -982,47 +1031,63 @@ static const struct media_entity_operations ti_csi2rx_video_entity_ops = {
 	.link_validate = ti_csi2rx_link_validate,
 };
 
-static int ti_csi2rx_init_dma(struct ti_csi2rx_dev *csi)
+static int ti_csi2rx_init_dma(struct ti_csi2rx_ctx *ctx)
 {
 	struct dma_slave_config cfg = {
 		.src_addr_width = DMA_SLAVE_BUSWIDTH_16_BYTES,
 	};
 	int ret;
 
-	INIT_LIST_HEAD(&csi->dma.queue);
-	INIT_LIST_HEAD(&csi->dma.submitted);
-	spin_lock_init(&csi->dma.lock);
-
-	csi->dma.state = TI_CSI2RX_DMA_STOPPED;
+	ctx->dma.chan = dma_request_chan(ctx->csi->dev, "rx0");
+	if (IS_ERR(ctx->dma.chan))
+		return PTR_ERR(ctx->dma.chan);
 
-	csi->dma.chan = dma_request_chan(csi->dev, "rx0");
-	if (IS_ERR(csi->dma.chan))
-		return PTR_ERR(csi->dma.chan);
-
-	ret = dmaengine_slave_config(csi->dma.chan, &cfg);
+	ret = dmaengine_slave_config(ctx->dma.chan, &cfg);
 	if (ret) {
-		dma_release_channel(csi->dma.chan);
+		dma_release_channel(ctx->dma.chan);
 		return ret;
 	}
 
-	csi->dma.drain.len = DRAIN_BUFFER_SIZE;
-	csi->dma.drain.vaddr = dma_alloc_coherent(csi->dev, csi->dma.drain.len,
-						  &csi->dma.drain.paddr,
-						  GFP_KERNEL);
-	if (!csi->dma.drain.vaddr)
-		return -ENOMEM;
-
 	return 0;
 }
 
 static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 {
 	struct media_device *mdev = &csi->mdev;
-	struct video_device *vdev = &csi->vdev;
+	int ret;
+
+	mdev->dev = csi->dev;
+	mdev->hw_revision = 1;
+	strscpy(mdev->model, "TI-CSI2RX", sizeof(mdev->model));
+
+	media_device_init(mdev);
+
+	csi->v4l2_dev.mdev = mdev;
+
+	ret = v4l2_device_register(csi->dev, &csi->v4l2_dev);
+	if (ret)
+		return ret;
+
+	ret = media_device_register(mdev);
+	if (ret) {
+		v4l2_device_unregister(&csi->v4l2_dev);
+		media_device_cleanup(mdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
+{
+	struct ti_csi2rx_dev *csi = ctx->csi;
+	struct video_device *vdev = &ctx->vdev;
 	const struct ti_csi2rx_fmt *fmt;
-	struct v4l2_pix_format *pix_fmt = &csi->v_fmt.fmt.pix;
+	struct v4l2_pix_format *pix_fmt = &ctx->v_fmt.fmt.pix;
 	int ret;
 
+	mutex_init(&ctx->mutex);
+
 	fmt = find_format_by_fourcc(V4L2_PIX_FMT_UYVY);
 	if (!fmt)
 		return -EINVAL;
@@ -1031,19 +1096,20 @@ static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 	pix_fmt->height = 480;
 	pix_fmt->field = V4L2_FIELD_NONE;
 	pix_fmt->colorspace = V4L2_COLORSPACE_SRGB;
-	pix_fmt->ycbcr_enc = V4L2_YCBCR_ENC_601;
-	pix_fmt->quantization = V4L2_QUANTIZATION_LIM_RANGE;
-	pix_fmt->xfer_func = V4L2_XFER_FUNC_SRGB;
-
-	ti_csi2rx_fill_fmt(fmt, &csi->v_fmt);
+	pix_fmt->ycbcr_enc = V4L2_YCBCR_ENC_601,
+	pix_fmt->quantization = V4L2_QUANTIZATION_LIM_RANGE,
+	pix_fmt->xfer_func = V4L2_XFER_FUNC_SRGB,
 
-	mdev->dev = csi->dev;
-	mdev->hw_revision = 1;
-	strscpy(mdev->model, "TI-CSI2RX", sizeof(mdev->model));
+	ti_csi2rx_fill_fmt(fmt, &ctx->v_fmt);
 
-	media_device_init(mdev);
+	csi->pad.flags = MEDIA_PAD_FL_SINK;
+	vdev->entity.ops = &ti_csi2rx_video_entity_ops;
+	ret = media_entity_pads_init(&ctx->vdev.entity, 1, &csi->pad);
+	if (ret)
+		return ret;
 
-	strscpy(vdev->name, TI_CSI2RX_MODULE_NAME, sizeof(vdev->name));
+	snprintf(vdev->name, sizeof(vdev->name), "%s context %u",
+		 dev_name(csi->dev), ctx->idx);
 	vdev->v4l2_dev = &csi->v4l2_dev;
 	vdev->vfl_dir = VFL_DIR_RX;
 	vdev->fops = &csi_fops;
@@ -1051,61 +1117,33 @@ static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 	vdev->release = video_device_release_empty;
 	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
 			    V4L2_CAP_IO_MC;
-	vdev->lock = &csi->mutex;
-	video_set_drvdata(vdev, csi);
-
-	csi->pad.flags = MEDIA_PAD_FL_SINK;
-	vdev->entity.ops = &ti_csi2rx_video_entity_ops;
-	ret = media_entity_pads_init(&csi->vdev.entity, 1, &csi->pad);
-	if (ret)
-		return ret;
+	vdev->lock = &ctx->mutex;
+	video_set_drvdata(vdev, ctx);
 
-	csi->v4l2_dev.mdev = mdev;
+	INIT_LIST_HEAD(&ctx->dma.queue);
+	INIT_LIST_HEAD(&ctx->dma.submitted);
+	spin_lock_init(&ctx->dma.lock);
+	ctx->dma.state = TI_CSI2RX_DMA_STOPPED;
 
-	ret = v4l2_device_register(csi->dev, &csi->v4l2_dev);
+	ret = ti_csi2rx_init_dma(ctx);
 	if (ret)
 		return ret;
 
-	ret = media_device_register(mdev);
-	if (ret) {
-		v4l2_device_unregister(&csi->v4l2_dev);
-		media_device_cleanup(mdev);
-		return ret;
-	}
+	ret = ti_csi2rx_init_vb2q(ctx);
+	if (ret)
+		goto cleanup_dma;
 
 	return 0;
-}
-
-static void ti_csi2rx_cleanup_dma(struct ti_csi2rx_dev *csi)
-{
-	dma_free_coherent(csi->dev, csi->dma.drain.len,
-			  csi->dma.drain.vaddr, csi->dma.drain.paddr);
-	csi->dma.drain.vaddr = NULL;
-	dma_release_channel(csi->dma.chan);
-}
-
-static void ti_csi2rx_cleanup_v4l2(struct ti_csi2rx_dev *csi)
-{
-	media_device_unregister(&csi->mdev);
-	v4l2_device_unregister(&csi->v4l2_dev);
-	media_device_cleanup(&csi->mdev);
-}
 
-static void ti_csi2rx_cleanup_subdev(struct ti_csi2rx_dev *csi)
-{
-	v4l2_async_nf_unregister(&csi->notifier);
-	v4l2_async_nf_cleanup(&csi->notifier);
-}
-
-static void ti_csi2rx_cleanup_vb2q(struct ti_csi2rx_dev *csi)
-{
-	vb2_queue_release(&csi->vidq);
+cleanup_dma:
+	dma_release_channel(ctx->dma.chan);
+	return ret;
 }
 
 static int ti_csi2rx_probe(struct platform_device *pdev)
 {
 	struct ti_csi2rx_dev *csi;
-	int ret;
+	int ret, i;
 
 	csi = devm_kzalloc(&pdev->dev, sizeof(*csi), GFP_KERNEL);
 	if (!csi)
@@ -1114,62 +1152,69 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 	csi->dev = &pdev->dev;
 	platform_set_drvdata(pdev, csi);
 
-	mutex_init(&csi->mutex);
 	csi->shim = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(csi->shim)) {
 		ret = PTR_ERR(csi->shim);
-		goto err_mutex;
+		return ret;
 	}
 
-	ret = ti_csi2rx_init_dma(csi);
-	if (ret)
-		goto err_mutex;
+	csi->drain.len = DRAIN_BUFFER_SIZE;
+	csi->drain.vaddr = dma_alloc_coherent(csi->dev, csi->drain.len,
+					      &csi->drain.paddr,
+					      GFP_KERNEL);
+	if (!csi->drain.vaddr)
+		return -ENOMEM;
 
 	ret = ti_csi2rx_v4l2_init(csi);
-	if (ret)
-		goto err_dma;
-
-	ret = ti_csi2rx_init_vb2q(csi);
 	if (ret)
 		goto err_v4l2;
 
+	for (i = 0; i < TI_CSI2RX_NUM_CTX; i++) {
+		csi->ctx[i].idx = i;
+		csi->ctx[i].csi = csi;
+		ret = ti_csi2rx_init_ctx(&csi->ctx[i]);
+		if (ret)
+			goto err_ctx;
+	}
+
 	ret = ti_csi2rx_notifier_register(csi);
 	if (ret)
-		goto err_vb2q;
+		goto err_ctx;
 
 	ret = devm_of_platform_populate(csi->dev);
 	if (ret) {
 		dev_err(csi->dev, "Failed to create children: %d\n", ret);
-		goto err_subdev;
+		goto err_notifier;
 	}
 
 	return 0;
 
-err_subdev:
-	ti_csi2rx_cleanup_subdev(csi);
-err_vb2q:
-	ti_csi2rx_cleanup_vb2q(csi);
-err_v4l2:
+err_notifier:
+	ti_csi2rx_cleanup_notifier(csi);
+err_ctx:
+	i--;
+	for (; i >= 0; i--)
+		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
 	ti_csi2rx_cleanup_v4l2(csi);
-err_dma:
-	ti_csi2rx_cleanup_dma(csi);
-err_mutex:
-	mutex_destroy(&csi->mutex);
+err_v4l2:
+	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
+			  csi->drain.paddr);
 	return ret;
 }
 
 static void ti_csi2rx_remove(struct platform_device *pdev)
 {
 	struct ti_csi2rx_dev *csi = platform_get_drvdata(pdev);
+	unsigned int i;
 
-	video_unregister_device(&csi->vdev);
+	for (i = 0; i < TI_CSI2RX_NUM_CTX; i++)
+		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
 
-	ti_csi2rx_cleanup_vb2q(csi);
-	ti_csi2rx_cleanup_subdev(csi);
+	ti_csi2rx_cleanup_notifier(csi);
 	ti_csi2rx_cleanup_v4l2(csi);
-	ti_csi2rx_cleanup_dma(csi);
 
-	mutex_destroy(&csi->mutex);
+	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
+			  csi->drain.paddr);
 }
 
 static const struct of_device_id ti_csi2rx_of_match[] = {
-- 
2.34.1

[PATCH v8 04/18] media: ti: j721e-csi2rx: prepare SHIM code for multiple contexts

[Rishikesh Donadkar]

From: Pratyush Yadav <p.yadav@ti.com>

Currently the SHIM code to configure the context only touches the first
context. Add support for writing to the context's registers based on the
context index.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c  | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 23717a3b6c4cf..fdbe72df5c5f8 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -27,7 +27,7 @@
 #define SHIM_CNTL			0x10
 #define SHIM_CNTL_PIX_RST		BIT(0)
 
-#define SHIM_DMACNTX			0x20
+#define SHIM_DMACNTX(i)			(0x20 + ((i) * 0x20))
 #define SHIM_DMACNTX_EN			BIT(31)
 #define SHIM_DMACNTX_YUV422		GENMASK(27, 26)
 #define SHIM_DMACNTX_DUAL_PCK_CFG	BIT(24)
@@ -38,7 +38,7 @@
 #define SHIM_DMACNTX_SIZE_16		1
 #define SHIM_DMACNTX_SIZE_32		2
 
-#define SHIM_PSI_CFG0			0x24
+#define SHIM_PSI_CFG0(i)		(0x24 + ((i) * 0x20))
 #define SHIM_PSI_CFG0_SRC_TAG		GENMASK(15, 0)
 #define SHIM_PSI_CFG0_DST_TAG		GENMASK(31, 16)
 
@@ -568,11 +568,13 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
 		break;
 	}
 
-	writel(reg, csi->shim + SHIM_DMACNTX);
+	reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
+
+	writel(reg, csi->shim + SHIM_DMACNTX(ctx->idx));
 
 	reg = FIELD_PREP(SHIM_PSI_CFG0_SRC_TAG, 0) |
 	      FIELD_PREP(SHIM_PSI_CFG0_DST_TAG, 0);
-	writel(reg, csi->shim + SHIM_PSI_CFG0);
+	writel(reg, csi->shim + SHIM_PSI_CFG0(ctx->idx));
 }
 
 static void ti_csi2rx_drain_callback(void *param)
@@ -890,7 +892,7 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 err_pipeline:
 	video_device_pipeline_stop(&ctx->vdev);
 	writel(0, csi->shim + SHIM_CNTL);
-	writel(0, csi->shim + SHIM_DMACNTX);
+	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
 err:
 	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
 	return ret;
@@ -905,7 +907,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 	video_device_pipeline_stop(&ctx->vdev);
 
 	writel(0, csi->shim + SHIM_CNTL);
-	writel(0, csi->shim + SHIM_DMACNTX);
+	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
 
 	ret = v4l2_subdev_call(csi->source, video, s_stream, 0);
 	if (ret)
-- 
2.34.1

[PATCH v8 05/18] media: ti: j721e-csi2rx: allocate DMA channel based on context index

[Rishikesh Donadkar]

From: Pratyush Yadav <p.yadav@ti.com>

With multiple contexts, there needs to be a different DMA channel for
each context. Earlier, the DMA channel name was hard coded to "rx0" for
the sake of simplicity. Generate the DMA channel name based on its index
and get the channel corresponding to the context.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index fdbe72df5c5f8..f66d68edcd57a 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -1038,9 +1038,11 @@ static int ti_csi2rx_init_dma(struct ti_csi2rx_ctx *ctx)
 	struct dma_slave_config cfg = {
 		.src_addr_width = DMA_SLAVE_BUSWIDTH_16_BYTES,
 	};
+	char name[5];
 	int ret;
 
-	ctx->dma.chan = dma_request_chan(ctx->csi->dev, "rx0");
+	snprintf(name, sizeof(name), "rx%u", ctx->idx);
+	ctx->dma.chan = dma_request_chan(ctx->csi->dev, name);
 	if (IS_ERR(ctx->dma.chan))
 		return PTR_ERR(ctx->dma.chan);
 
-- 
2.34.1

[PATCH v8 06/18] media: ti: j721e-csi2rx: add a subdev for the core device

[Rishikesh Donadkar]

From: Jai Luthra <j-luthra@ti.com>

With single stream capture, it was simpler to use the video device as
the media entity representing the main TI CSI2RX device. Now with multi
stream capture coming into the picture, the model has shifted to each
video device having a link to the main device's subdev. The routing
would then be set on this subdev.

Add this subdev, link each context to this subdev's entity and link the
subdev's entity to the source. Also add an array of media pads. It will
have one sink pad and source pads equal to the number of contexts.

Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 281 +++++++++++++++---
 1 file changed, 237 insertions(+), 44 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index f66d68edcd57a..327b8e5fb7d5e 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -54,6 +54,11 @@
 #define MAX_WIDTH_BYTES			SZ_16K
 #define MAX_HEIGHT_LINES		SZ_16K
 
+#define TI_CSI2RX_PAD_SINK		0
+#define TI_CSI2RX_PAD_FIRST_SOURCE	1
+#define TI_CSI2RX_NUM_SOURCE_PADS	1
+#define TI_CSI2RX_NUM_PADS		(1 + TI_CSI2RX_NUM_SOURCE_PADS)
+
 #define DRAIN_TIMEOUT_MS		50
 #define DRAIN_BUFFER_SIZE		SZ_32K
 
@@ -102,6 +107,7 @@ struct ti_csi2rx_ctx {
 	struct mutex			mutex; /* To serialize ioctls. */
 	struct v4l2_format		v_fmt;
 	struct ti_csi2rx_dma		dma;
+	struct media_pad		pad;
 	u32				sequence;
 	u32				idx;
 };
@@ -109,12 +115,15 @@ struct ti_csi2rx_ctx {
 struct ti_csi2rx_dev {
 	struct device			*dev;
 	void __iomem			*shim;
+	struct mutex			mutex; /* To serialize ioctls. */
+	unsigned int			enable_count;
 	struct v4l2_device		v4l2_dev;
 	struct media_device		mdev;
 	struct media_pipeline		pipe;
-	struct media_pad		pad;
+	struct media_pad		pads[TI_CSI2RX_NUM_PADS];
 	struct v4l2_async_notifier	notifier;
 	struct v4l2_subdev		*source;
+	struct v4l2_subdev		subdev;
 	struct ti_csi2rx_ctx		ctx[TI_CSI2RX_NUM_CTX];
 	u8				pix_per_clk;
 	/* Buffer to drain stale data from PSI-L endpoint */
@@ -125,6 +134,22 @@ struct ti_csi2rx_dev {
 	} drain;
 };
 
+static inline struct ti_csi2rx_dev *to_csi2rx_dev(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct ti_csi2rx_dev, subdev);
+}
+
+static const struct v4l2_mbus_framefmt ti_csi2rx_default_fmt = {
+	.width = 640,
+	.height = 480,
+	.code = MEDIA_BUS_FMT_UYVY8_1X16,
+	.field = V4L2_FIELD_NONE,
+	.colorspace = V4L2_COLORSPACE_SRGB,
+	.ycbcr_enc = V4L2_YCBCR_ENC_601,
+	.quantization = V4L2_QUANTIZATION_LIM_RANGE,
+	.xfer_func = V4L2_XFER_FUNC_SRGB,
+};
+
 static const struct ti_csi2rx_fmt ti_csi2rx_formats[] = {
 	{
 		.fourcc			= V4L2_PIX_FMT_YUYV,
@@ -422,6 +447,18 @@ static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
 	struct ti_csi2rx_dev *csi = dev_get_drvdata(notifier->v4l2_dev->dev);
 	int ret, i;
 
+	/* Create link from source to subdev */
+	ret = media_create_pad_link(&csi->source->entity,
+				    CSI2RX_BRIDGE_SOURCE_PAD,
+				    &csi->subdev.entity,
+				    TI_CSI2RX_PAD_SINK,
+				    MEDIA_LNK_FL_IMMUTABLE |
+				    MEDIA_LNK_FL_ENABLED);
+
+	if (ret)
+		return ret;
+
+	/* Create and link video nodes for all DMA contexts */
 	for (i = 0; i < TI_CSI2RX_NUM_CTX; i++) {
 		struct ti_csi2rx_ctx *ctx = &csi->ctx[i];
 		struct video_device *vdev = &ctx->vdev;
@@ -429,15 +466,17 @@ static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
 		ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
 		if (ret)
 			goto unregister_dev;
-	}
 
-	ret = media_create_pad_link(&csi->source->entity,
-				    CSI2RX_BRIDGE_SOURCE_PAD,
-				    &csi->ctx[0].vdev.entity, csi->pad.index,
-				    MEDIA_LNK_FL_IMMUTABLE |
-				    MEDIA_LNK_FL_ENABLED);
-	if (ret)
-		goto unregister_dev;
+		ret = media_create_pad_link(&csi->subdev.entity,
+					    TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
+					    &vdev->entity, 0,
+					    MEDIA_LNK_FL_IMMUTABLE |
+					    MEDIA_LNK_FL_ENABLED);
+		if (ret) {
+			video_unregister_device(vdev);
+			goto unregister_dev;
+		}
+	}
 
 	ret = v4l2_device_register_subdev_nodes(&csi->v4l2_dev);
 	if (ret)
@@ -447,8 +486,10 @@ static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
 
 unregister_dev:
 	i--;
-	for (; i >= 0; i--)
+	for (; i >= 0; i--) {
+		media_entity_remove_links(&csi->ctx[i].vdev.entity);
 		video_unregister_device(&csi->ctx[i].vdev);
+	}
 	return ret;
 }
 
@@ -493,14 +534,13 @@ static int ti_csi2rx_notifier_register(struct ti_csi2rx_dev *csi)
 }
 
 /* Request maximum possible pixels per clock from the bridge */
-static void ti_csi2rx_request_max_ppc(struct ti_csi2rx_ctx *ctx)
+static void ti_csi2rx_request_max_ppc(struct ti_csi2rx_dev *csi)
 {
-	struct ti_csi2rx_dev *csi = ctx->csi;
 	u8 ppc = TI_CSI2RX_MAX_PIX_PER_CLK;
 	struct media_pad *pad;
 	int ret;
 
-	pad = media_entity_remote_source_pad_unique(&ctx->vdev.entity);
+	pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
 	if (IS_ERR(pad))
 		return;
 
@@ -526,7 +566,7 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
 	writel(reg, csi->shim + SHIM_CNTL);
 
 	/* Negotiate pixel count from the source */
-	ti_csi2rx_request_max_ppc(ctx);
+	ti_csi2rx_request_max_ppc(csi);
 
 	reg = SHIM_DMACNTX_EN;
 	reg |= FIELD_PREP(SHIM_DMACNTX_FMT, fmt->csi_dt);
@@ -881,7 +921,7 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	dma->state = TI_CSI2RX_DMA_ACTIVE;
 	spin_unlock_irqrestore(&dma->lock, flags);
 
-	ret = v4l2_subdev_call(csi->source, video, s_stream, 1);
+	ret = v4l2_subdev_call(&csi->subdev, video, s_stream, 1);
 	if (ret)
 		goto err_dma;
 
@@ -909,7 +949,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 	writel(0, csi->shim + SHIM_CNTL);
 	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
 
-	ret = v4l2_subdev_call(csi->source, video, s_stream, 0);
+	ret = v4l2_subdev_call(&csi->subdev, video, s_stream, 0);
 	if (ret)
 		dev_err(csi->dev, "Failed to stop subdev stream\n");
 
@@ -925,8 +965,114 @@ static const struct vb2_ops csi_vb2_qops = {
 	.stop_streaming = ti_csi2rx_stop_streaming,
 };
 
+static int ti_csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
+				    struct v4l2_subdev_state *state,
+				    struct v4l2_subdev_mbus_code_enum *code_enum)
+{
+	if (code_enum->index >= ARRAY_SIZE(ti_csi2rx_formats))
+		return -EINVAL;
+
+	code_enum->code = ti_csi2rx_formats[code_enum->index].code;
+
+	return 0;
+}
+
+static int ti_csi2rx_sd_set_fmt(struct v4l2_subdev *sd,
+				struct v4l2_subdev_state *state,
+				struct v4l2_subdev_format *format)
+{
+	struct v4l2_mbus_framefmt *fmt;
+
+	/* No transcoding, don't allow setting source fmt */
+	if (format->pad > TI_CSI2RX_PAD_SINK)
+		return v4l2_subdev_get_fmt(sd, state, format);
+
+	if (!find_format_by_code(format->format.code))
+		format->format.code = ti_csi2rx_formats[0].code;
+
+	format->format.field = V4L2_FIELD_NONE;
+
+	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
+	*fmt = format->format;
+
+	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE,
+					   format->stream);
+	*fmt = format->format;
+
+	return 0;
+}
+
+static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_state *state)
+{
+	struct v4l2_mbus_framefmt *fmt;
+
+	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_SINK);
+	*fmt = ti_csi2rx_default_fmt;
+
+	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE);
+	*fmt = ti_csi2rx_default_fmt;
+
+	return 0;
+}
+
+static int ti_csi2rx_sd_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
+	int ret = 0;
+
+	mutex_lock(&csi->mutex);
+
+	if (enable) {
+		if (csi->enable_count > 0) {
+			csi->enable_count++;
+			goto out;
+		}
+
+		ret = v4l2_subdev_call(csi->source, video, s_stream, 1);
+		if (ret)
+			goto out;
+
+		csi->enable_count++;
+	} else {
+		if (csi->enable_count == 0) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		if (--csi->enable_count > 0)
+			goto out;
+
+		ret = v4l2_subdev_call(csi->source, video, s_stream, 0);
+	}
+
+out:
+	mutex_unlock(&csi->mutex);
+	return ret;
+}
+
+static const struct v4l2_subdev_pad_ops ti_csi2rx_subdev_pad_ops = {
+	.enum_mbus_code	= ti_csi2rx_enum_mbus_code,
+	.get_fmt = v4l2_subdev_get_fmt,
+	.set_fmt = ti_csi2rx_sd_set_fmt,
+};
+
+static const struct v4l2_subdev_video_ops ti_csi2rx_subdev_video_ops = {
+	.s_stream = ti_csi2rx_sd_s_stream,
+};
+
+static const struct v4l2_subdev_ops ti_csi2rx_subdev_ops = {
+	.video = &ti_csi2rx_subdev_video_ops,
+	.pad = &ti_csi2rx_subdev_pad_ops,
+};
+
+static const struct v4l2_subdev_internal_ops ti_csi2rx_internal_ops = {
+	.init_state = ti_csi2rx_sd_init_state,
+};
+
 static void ti_csi2rx_cleanup_v4l2(struct ti_csi2rx_dev *csi)
 {
+	v4l2_subdev_cleanup(&csi->subdev);
 	media_device_unregister(&csi->mdev);
 	v4l2_device_unregister(&csi->v4l2_dev);
 	media_device_cleanup(&csi->mdev);
@@ -981,48 +1127,52 @@ static int ti_csi2rx_link_validate(struct media_link *link)
 	struct ti_csi2rx_ctx *ctx = container_of(vdev, struct ti_csi2rx_ctx, vdev);
 	struct ti_csi2rx_dev *csi = ctx->csi;
 	struct v4l2_pix_format *csi_fmt = &ctx->v_fmt.fmt.pix;
-	struct v4l2_subdev_format source_fmt = {
-		.which	= V4L2_SUBDEV_FORMAT_ACTIVE,
-		.pad	= link->source->index,
-	};
+	struct v4l2_mbus_framefmt *format;
+	struct v4l2_subdev_state *state;
 	const struct ti_csi2rx_fmt *ti_fmt;
-	int ret;
 
-	ret = v4l2_subdev_call_state_active(csi->source, pad,
-					    get_fmt, &source_fmt);
-	if (ret)
-		return ret;
+	state = v4l2_subdev_lock_and_get_active_state(&csi->subdev);
+	format = v4l2_subdev_state_get_format(state, link->source->index, 0);
+	v4l2_subdev_unlock_state(state);
 
-	if (source_fmt.format.width != csi_fmt->width) {
+	if (!format) {
+		dev_dbg(csi->dev,
+			"Skipping validation as no format present on \"%s\":%u:0\n",
+			link->source->entity->name, link->source->index);
+		return 0;
+	}
+
+	if (format->width != csi_fmt->width) {
 		dev_dbg(csi->dev, "Width does not match (source %u, sink %u)\n",
-			source_fmt.format.width, csi_fmt->width);
+			format->width, csi_fmt->width);
 		return -EPIPE;
 	}
 
-	if (source_fmt.format.height != csi_fmt->height) {
+	if (format->height != csi_fmt->height) {
 		dev_dbg(csi->dev, "Height does not match (source %u, sink %u)\n",
-			source_fmt.format.height, csi_fmt->height);
+			format->height, csi_fmt->height);
 		return -EPIPE;
 	}
 
-	if (source_fmt.format.field != csi_fmt->field &&
+	if (format->field != csi_fmt->field &&
 	    csi_fmt->field != V4L2_FIELD_NONE) {
 		dev_dbg(csi->dev, "Field does not match (source %u, sink %u)\n",
-			source_fmt.format.field, csi_fmt->field);
+			format->field, csi_fmt->field);
 		return -EPIPE;
 	}
 
-	ti_fmt = find_format_by_code(source_fmt.format.code);
+	ti_fmt = find_format_by_code(format->code);
 	if (!ti_fmt) {
 		dev_dbg(csi->dev, "Media bus format 0x%x not supported\n",
-			source_fmt.format.code);
+			format->code);
 		return -EPIPE;
 	}
 
 	if (ti_fmt->fourcc != csi_fmt->pixelformat) {
 		dev_dbg(csi->dev,
-			"Cannot transform source fmt 0x%x to sink fmt 0x%x\n",
-			ti_fmt->fourcc, csi_fmt->pixelformat);
+			"Cannot transform \"%s\":%u format %p4cc to %p4cc\n",
+			link->source->entity->name, link->source->index,
+			&ti_fmt->fourcc, &csi_fmt->pixelformat);
 		return -EPIPE;
 	}
 
@@ -1033,6 +1183,10 @@ static const struct media_entity_operations ti_csi2rx_video_entity_ops = {
 	.link_validate = ti_csi2rx_link_validate,
 };
 
+static const struct media_entity_operations ti_csi2rx_subdev_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
 static int ti_csi2rx_init_dma(struct ti_csi2rx_ctx *ctx)
 {
 	struct dma_slave_config cfg = {
@@ -1058,6 +1212,7 @@ static int ti_csi2rx_init_dma(struct ti_csi2rx_ctx *ctx)
 static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 {
 	struct media_device *mdev = &csi->mdev;
+	struct v4l2_subdev *sd = &csi->subdev;
 	int ret;
 
 	mdev->dev = csi->dev;
@@ -1070,16 +1225,51 @@ static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 
 	ret = v4l2_device_register(csi->dev, &csi->v4l2_dev);
 	if (ret)
-		return ret;
+		goto cleanup_media;
 
 	ret = media_device_register(mdev);
-	if (ret) {
-		v4l2_device_unregister(&csi->v4l2_dev);
-		media_device_cleanup(mdev);
-		return ret;
-	}
+	if (ret)
+		goto unregister_v4l2;
+
+	v4l2_subdev_init(sd, &ti_csi2rx_subdev_ops);
+	sd->internal_ops = &ti_csi2rx_internal_ops;
+	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	sd->flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
+	strscpy(sd->name, dev_name(csi->dev), sizeof(sd->name));
+	sd->dev = csi->dev;
+	sd->entity.ops = &ti_csi2rx_subdev_entity_ops;
+
+	csi->pads[TI_CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
+
+	for (unsigned int i = TI_CSI2RX_PAD_FIRST_SOURCE;
+	     i < TI_CSI2RX_NUM_PADS; i++)
+		csi->pads[i].flags = MEDIA_PAD_FL_SOURCE;
+
+	ret = media_entity_pads_init(&sd->entity, ARRAY_SIZE(csi->pads),
+				     csi->pads);
+	if (ret)
+		goto unregister_media;
+
+	ret = v4l2_subdev_init_finalize(sd);
+	if (ret)
+		goto unregister_media;
+
+	ret = v4l2_device_register_subdev(&csi->v4l2_dev, sd);
+	if (ret)
+		goto cleanup_subdev;
 
 	return 0;
+
+cleanup_subdev:
+	v4l2_subdev_cleanup(sd);
+unregister_media:
+	media_device_unregister(mdev);
+unregister_v4l2:
+	v4l2_device_unregister(&csi->v4l2_dev);
+cleanup_media:
+	media_device_cleanup(mdev);
+
+	return ret;
 }
 
 static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
@@ -1106,9 +1296,9 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
 
 	ti_csi2rx_fill_fmt(fmt, &ctx->v_fmt);
 
-	csi->pad.flags = MEDIA_PAD_FL_SINK;
+	ctx->pad.flags = MEDIA_PAD_FL_SINK;
 	vdev->entity.ops = &ti_csi2rx_video_entity_ops;
-	ret = media_entity_pads_init(&ctx->vdev.entity, 1, &csi->pad);
+	ret = media_entity_pads_init(&ctx->vdev.entity, 1, &ctx->pad);
 	if (ret)
 		return ret;
 
@@ -1169,6 +1359,8 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 	if (!csi->drain.vaddr)
 		return -ENOMEM;
 
+	mutex_init(&csi->mutex);
+
 	ret = ti_csi2rx_v4l2_init(csi);
 	if (ret)
 		goto err_v4l2;
@@ -1201,6 +1393,7 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
 	ti_csi2rx_cleanup_v4l2(csi);
 err_v4l2:
+	mutex_destroy(&csi->mutex);
 	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
 			  csi->drain.paddr);
 	return ret;
@@ -1216,7 +1409,7 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
 
 	ti_csi2rx_cleanup_notifier(csi);
 	ti_csi2rx_cleanup_v4l2(csi);
-
+	mutex_destroy(&csi->mutex);
 	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
 			  csi->drain.paddr);
 }
-- 
2.34.1

[PATCH v8 07/18] media: cadence: csi2rx: Move to .enable/disable_streams API

[Rishikesh Donadkar]

The enable_streams() API in v4l2 supports passing a bitmask to enable
each pad/stream combination individually on any media subdev. Use this
API instead of  s_stream() API.

Implement the enable_stream and disable_stream hooks in place of the
stream-unaware s_stream hook.

Remove the lock that was used to serialize stream starts/stops which
is not required anymore since the v4l2-core serializes the
enable/disable_streams() calls for the subdev.

Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 108 +++++++++----------
 1 file changed, 54 insertions(+), 54 deletions(-)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 8c19f125da3e5..34da81893308b 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -125,12 +125,6 @@ struct csi2rx_priv {
 	unsigned int			count;
 	int				error_irq;
 
-	/*
-	 * Used to prevent race conditions between multiple,
-	 * concurrent calls to start and stop.
-	 */
-	struct mutex			lock;
-
 	void __iomem			*base;
 	struct clk			*sys_clk;
 	struct clk			*p_clk;
@@ -268,20 +262,21 @@ static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
 		&csi2rx->source_subdev->entity.pads[csi2rx->source_pad];
 	union phy_configure_opts opts = { };
 	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
-	struct v4l2_subdev_format sd_fmt = {
-		.which	= V4L2_SUBDEV_FORMAT_ACTIVE,
-		.pad	= CSI2RX_PAD_SINK,
-	};
+	struct v4l2_subdev_state *state;
+	struct v4l2_mbus_framefmt *framefmt;
 	const struct csi2rx_fmt *fmt;
 	s64 link_freq;
 	int ret;
 
-	ret = v4l2_subdev_call_state_active(&csi2rx->subdev, pad, get_fmt,
-					    &sd_fmt);
-	if (ret < 0)
-		return ret;
+	state = v4l2_subdev_get_locked_active_state(&csi2rx->subdev);
 
-	fmt = csi2rx_get_fmt_by_code(sd_fmt.format.code);
+	framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
+	if (!framefmt) {
+		dev_err(csi2rx->dev, "Did not find active sink format\n");
+		return -EINVAL;
+	}
+
+	fmt = csi2rx_get_fmt_by_code(framefmt->code);
 
 	link_freq = v4l2_get_link_freq(src_pad,
 				       fmt->bpp, 2 * csi2rx->num_lanes);
@@ -401,16 +396,10 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 
 	reset_control_deassert(csi2rx->sys_rst);
 
-	ret = v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, true);
-	if (ret)
-		goto err_disable_sysclk;
-
 	clk_disable_unprepare(csi2rx->p_clk);
 
 	return 0;
 
-err_disable_sysclk:
-	clk_disable_unprepare(csi2rx->sys_clk);
 err_disable_pixclk:
 	for (; i > 0; i--) {
 		reset_control_assert(csi2rx->pixel_rst[i - 1]);
@@ -459,9 +448,6 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
 	reset_control_assert(csi2rx->p_rst);
 	clk_disable_unprepare(csi2rx->p_clk);
 
-	if (v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false))
-		dev_warn(csi2rx->dev, "Couldn't disable our subdev\n");
-
 	if (csi2rx->dphy) {
 		writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
 
@@ -485,38 +471,56 @@ static int csi2rx_log_status(struct v4l2_subdev *sd)
 	return 0;
 }
 
-static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
+static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
+				 struct v4l2_subdev_state *state, u32 pad,
+				 u64 streams_mask)
 {
 	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
-	int ret = 0;
-
-	mutex_lock(&csi2rx->lock);
-
-	if (enable) {
-		/*
-		 * If we're not the first users, there's no need to
-		 * enable the whole controller.
-		 */
-		if (!csi2rx->count) {
-			ret = csi2rx_start(csi2rx);
-			if (ret)
-				goto out;
-		}
+	int ret;
 
-		csi2rx->count++;
-	} else {
-		csi2rx->count--;
+	/*
+	 * If we're not the first users, there's no need to
+	 * enable the whole controller.
+	 */
+	if (!csi2rx->count) {
+		ret = csi2rx_start(csi2rx);
+		if (ret)
+			return ret;
+	}
 
-		/*
-		 * Let the last user turn off the lights.
-		 */
+	/* Start streaming on the source */
+	ret = v4l2_subdev_enable_streams(csi2rx->source_subdev, csi2rx->source_pad,
+					 BIT(0));
+	if (ret) {
+		dev_err(csi2rx->dev,
+			"Failed to start streams %d on subdev\n", 0);
 		if (!csi2rx->count)
 			csi2rx_stop(csi2rx);
+		return ret;
 	}
 
-out:
-	mutex_unlock(&csi2rx->lock);
-	return ret;
+	csi2rx->count++;
+	return 0;
+}
+
+static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
+				  struct v4l2_subdev_state *state, u32 pad,
+				  u64 streams_mask)
+{
+	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+
+	if (v4l2_subdev_disable_streams(csi2rx->source_subdev,
+					csi2rx->source_pad, BIT(0))) {
+		dev_err(csi2rx->dev, "Couldn't disable our subdev\n");
+	}
+
+	csi2rx->count--;
+
+	/* Let the last user turn off the lights. */
+	if (!csi2rx->count)
+		csi2rx_stop(csi2rx);
+
+	return 0;
 }
 
 static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
@@ -611,10 +615,8 @@ static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
 	.enum_mbus_code	= csi2rx_enum_mbus_code,
 	.get_fmt	= v4l2_subdev_get_fmt,
 	.set_fmt	= csi2rx_set_fmt,
-};
-
-static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
-	.s_stream	= csi2rx_s_stream,
+	.enable_streams         = csi2rx_enable_streams,
+	.disable_streams        = csi2rx_disable_streams,
 };
 
 static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
@@ -623,7 +625,6 @@ static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
 
 static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
 	.core		= &csi2rx_core_ops,
-	.video		= &csi2rx_video_ops,
 	.pad		= &csi2rx_pad_ops,
 };
 
@@ -829,7 +830,6 @@ static int csi2rx_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	platform_set_drvdata(pdev, csi2rx);
 	csi2rx->dev = &pdev->dev;
-	mutex_init(&csi2rx->lock);
 
 	ret = csi2rx_get_resources(csi2rx, pdev);
 	if (ret)
-- 
2.34.1

[PATCH v8 08/18] media: ti: j721e-csi2rx: Move to .enable/disable_streams API

[Rishikesh Donadkar]

Support the new enable_stream()/disable_stream() APIs in the subdev
instead of s_stream() hook.

Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 71 +++++++++++--------
 1 file changed, 41 insertions(+), 30 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 327b8e5fb7d5e..372a4035d78a0 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -921,7 +921,9 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	dma->state = TI_CSI2RX_DMA_ACTIVE;
 	spin_unlock_irqrestore(&dma->lock, flags);
 
-	ret = v4l2_subdev_call(&csi->subdev, video, s_stream, 1);
+	ret = v4l2_subdev_enable_streams(&csi->subdev,
+					 TI_CSI2RX_PAD_FIRST_SOURCE,
+					 BIT(0));
 	if (ret)
 		goto err_dma;
 
@@ -949,7 +951,9 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 	writel(0, csi->shim + SHIM_CNTL);
 	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
 
-	ret = v4l2_subdev_call(&csi->subdev, video, s_stream, 0);
+	ret = v4l2_subdev_disable_streams(&csi->subdev,
+					  TI_CSI2RX_PAD_FIRST_SOURCE,
+					  BIT(0));
 	if (ret)
 		dev_err(csi->dev, "Failed to stop subdev stream\n");
 
@@ -1016,53 +1020,60 @@ static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
 	return 0;
 }
 
-static int ti_csi2rx_sd_s_stream(struct v4l2_subdev *sd, int enable)
+static int ti_csi2rx_sd_enable_streams(struct v4l2_subdev *sd,
+				       struct v4l2_subdev_state *state,
+				       u32 pad, u64 streams_mask)
 {
 	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
+	struct media_pad *remote_pad;
 	int ret = 0;
 
-	mutex_lock(&csi->mutex);
+	remote_pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
+	if (!remote_pad)
+		return -ENODEV;
 
-	if (enable) {
-		if (csi->enable_count > 0) {
-			csi->enable_count++;
-			goto out;
-		}
+	ret = v4l2_subdev_enable_streams(csi->source, remote_pad->index,
+					 BIT(0));
+	if (ret)
+		return ret;
 
-		ret = v4l2_subdev_call(csi->source, video, s_stream, 1);
-		if (ret)
-			goto out;
+	csi->enable_count++;
 
-		csi->enable_count++;
-	} else {
-		if (csi->enable_count == 0) {
-			ret = -EINVAL;
-			goto out;
-		}
+	return 0;
+}
+
+static int ti_csi2rx_sd_disable_streams(struct v4l2_subdev *sd,
+					struct v4l2_subdev_state *state,
+					u32 pad, u64 streams_mask)
+{
+	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
+	struct media_pad *remote_pad;
+	int ret = 0;
 
-		if (--csi->enable_count > 0)
-			goto out;
+	remote_pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
+	if (!remote_pad)
+		return -ENODEV;
 
-		ret = v4l2_subdev_call(csi->source, video, s_stream, 0);
-	}
+	if (csi->enable_count == 0)
+		return -EINVAL;
 
-out:
-	mutex_unlock(&csi->mutex);
-	return ret;
+	ret = v4l2_subdev_disable_streams(csi->source, remote_pad->index,
+					  BIT(0));
+	if (!ret)
+		--csi->enable_count;
+
+	return 0;
 }
 
 static const struct v4l2_subdev_pad_ops ti_csi2rx_subdev_pad_ops = {
 	.enum_mbus_code	= ti_csi2rx_enum_mbus_code,
 	.get_fmt = v4l2_subdev_get_fmt,
 	.set_fmt = ti_csi2rx_sd_set_fmt,
-};
-
-static const struct v4l2_subdev_video_ops ti_csi2rx_subdev_video_ops = {
-	.s_stream = ti_csi2rx_sd_s_stream,
+	.enable_streams = ti_csi2rx_sd_enable_streams,
+	.disable_streams = ti_csi2rx_sd_disable_streams,
 };
 
 static const struct v4l2_subdev_ops ti_csi2rx_subdev_ops = {
-	.video = &ti_csi2rx_subdev_video_ops,
 	.pad = &ti_csi2rx_subdev_pad_ops,
 };
 
-- 
2.34.1

[PATCH v8 09/18] media: ti: j721e-csi2rx: get number of contexts from device tree

[Rishikesh Donadkar]

From: Pratyush Yadav <p.yadav@ti.com>

Different platforms that use this driver might have different number of
DMA channels allocated for CSI. So only as many DMA contexts can be used
as the number of DMA channels available. Get the number of channels
provided via device tree and only configure that many contexts, and
hence only that many pads.

Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Co-developed-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 43 ++++++++++++++-----
 1 file changed, 32 insertions(+), 11 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 372a4035d78a0..5c4524bf42e6e 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -43,7 +43,7 @@
 #define SHIM_PSI_CFG0_DST_TAG		GENMASK(31, 16)
 
 #define TI_CSI2RX_MAX_PIX_PER_CLK	4
-#define TI_CSI2RX_NUM_CTX		1
+#define TI_CSI2RX_MAX_CTX		32
 
 /*
  * There are no hard limits on the width or height. The DMA engine can handle
@@ -56,8 +56,8 @@
 
 #define TI_CSI2RX_PAD_SINK		0
 #define TI_CSI2RX_PAD_FIRST_SOURCE	1
-#define TI_CSI2RX_NUM_SOURCE_PADS	1
-#define TI_CSI2RX_NUM_PADS		(1 + TI_CSI2RX_NUM_SOURCE_PADS)
+#define TI_CSI2RX_MAX_SOURCE_PADS	TI_CSI2RX_MAX_CTX
+#define TI_CSI2RX_MAX_PADS		(1 + TI_CSI2RX_MAX_SOURCE_PADS)
 
 #define DRAIN_TIMEOUT_MS		50
 #define DRAIN_BUFFER_SIZE		SZ_32K
@@ -117,14 +117,15 @@ struct ti_csi2rx_dev {
 	void __iomem			*shim;
 	struct mutex			mutex; /* To serialize ioctls. */
 	unsigned int			enable_count;
+	unsigned int			num_ctx;
 	struct v4l2_device		v4l2_dev;
 	struct media_device		mdev;
 	struct media_pipeline		pipe;
-	struct media_pad		pads[TI_CSI2RX_NUM_PADS];
+	struct media_pad		pads[TI_CSI2RX_MAX_PADS];
 	struct v4l2_async_notifier	notifier;
 	struct v4l2_subdev		*source;
 	struct v4l2_subdev		subdev;
-	struct ti_csi2rx_ctx		ctx[TI_CSI2RX_NUM_CTX];
+	struct ti_csi2rx_ctx		ctx[TI_CSI2RX_MAX_CTX];
 	u8				pix_per_clk;
 	/* Buffer to drain stale data from PSI-L endpoint */
 	struct {
@@ -459,7 +460,7 @@ static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
 		return ret;
 
 	/* Create and link video nodes for all DMA contexts */
-	for (i = 0; i < TI_CSI2RX_NUM_CTX; i++) {
+	for (i = 0; i < csi->num_ctx; i++) {
 		struct ti_csi2rx_ctx *ctx = &csi->ctx[i];
 		struct video_device *vdev = &ctx->vdev;
 
@@ -1253,10 +1254,11 @@ static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 	csi->pads[TI_CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
 
 	for (unsigned int i = TI_CSI2RX_PAD_FIRST_SOURCE;
-	     i < TI_CSI2RX_NUM_PADS; i++)
+	     i < TI_CSI2RX_PAD_FIRST_SOURCE + csi->num_ctx; i++)
 		csi->pads[i].flags = MEDIA_PAD_FL_SOURCE;
 
-	ret = media_entity_pads_init(&sd->entity, ARRAY_SIZE(csi->pads),
+	ret = media_entity_pads_init(&sd->entity,
+				     TI_CSI2RX_PAD_FIRST_SOURCE + csi->num_ctx,
 				     csi->pads);
 	if (ret)
 		goto unregister_media;
@@ -1347,8 +1349,9 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
 
 static int ti_csi2rx_probe(struct platform_device *pdev)
 {
+	struct device_node *np = pdev->dev.of_node;
 	struct ti_csi2rx_dev *csi;
-	int ret, i;
+	int ret = 0, i, count;
 
 	csi = devm_kzalloc(&pdev->dev, sizeof(*csi), GFP_KERNEL);
 	if (!csi)
@@ -1370,13 +1373,30 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 	if (!csi->drain.vaddr)
 		return -ENOMEM;
 
+	/* Only use as many contexts as the number of DMA channels allocated. */
+	count = of_property_count_strings(np, "dma-names");
+	if (count < 0) {
+		dev_err(csi->dev, "Failed to get DMA channel count: %d\n", count);
+		ret = count;
+		goto err_dma_chan;
+	}
+
+	csi->num_ctx = count;
+	if (csi->num_ctx > TI_CSI2RX_MAX_CTX) {
+		dev_err(csi->dev,
+			"%u DMA channels passed. Maximum is %u.\n",
+			csi->num_ctx, TI_CSI2RX_MAX_CTX);
+		ret = -EINVAL;
+		goto err_dma_chan;
+	}
+
 	mutex_init(&csi->mutex);
 
 	ret = ti_csi2rx_v4l2_init(csi);
 	if (ret)
 		goto err_v4l2;
 
-	for (i = 0; i < TI_CSI2RX_NUM_CTX; i++) {
+	for (i = 0; i < csi->num_ctx; i++) {
 		csi->ctx[i].idx = i;
 		csi->ctx[i].csi = csi;
 		ret = ti_csi2rx_init_ctx(&csi->ctx[i]);
@@ -1405,6 +1425,7 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 	ti_csi2rx_cleanup_v4l2(csi);
 err_v4l2:
 	mutex_destroy(&csi->mutex);
+err_dma_chan:
 	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
 			  csi->drain.paddr);
 	return ret;
@@ -1415,7 +1436,7 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
 	struct ti_csi2rx_dev *csi = platform_get_drvdata(pdev);
 	unsigned int i;
 
-	for (i = 0; i < TI_CSI2RX_NUM_CTX; i++)
+	for (i = 0; i < csi->num_ctx; i++)
 		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
 
 	ti_csi2rx_cleanup_notifier(csi);
-- 
2.34.1

[PATCH v8 10/18] media: cadence: csi2rx: add get_frame_desc wrapper

[Rishikesh Donadkar]

From: Pratyush Yadav <p.yadav@ti.com>

J721E wrapper CSI2RX driver needs to get the frame descriptor from the
source to find out info about virtual channel. This driver itself does
not touch the routing or virtual channels in any way. So simply pass the
descriptor through from the source.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 24 ++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 34da81893308b..3688077fa8347 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -229,6 +229,21 @@ static const struct csi2rx_fmt *csi2rx_get_fmt_by_code(u32 code)
 	return NULL;
 }
 
+static int csi2rx_get_frame_desc_from_source(struct csi2rx_priv *csi2rx,
+					     struct v4l2_mbus_frame_desc *fd)
+{
+	struct media_pad *remote_pad;
+
+	remote_pad = media_entity_remote_source_pad_unique(&csi2rx->subdev.entity);
+	if (!remote_pad) {
+		dev_err(csi2rx->dev, "No remote pad found for sink\n");
+		return -ENODEV;
+	}
+
+	return v4l2_subdev_call(csi2rx->source_subdev, pad, get_frame_desc,
+				remote_pad->index, fd);
+}
+
 static inline
 struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)
 {
@@ -611,12 +626,21 @@ int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
 }
 EXPORT_SYMBOL_FOR_MODULES(cdns_csi2rx_negotiate_ppc, "j721e-csi2rx");
 
+static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
+				 struct v4l2_mbus_frame_desc *fd)
+{
+	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+
+	return csi2rx_get_frame_desc_from_source(csi2rx, fd);
+}
+
 static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
 	.enum_mbus_code	= csi2rx_enum_mbus_code,
 	.get_fmt	= v4l2_subdev_get_fmt,
 	.set_fmt	= csi2rx_set_fmt,
 	.enable_streams         = csi2rx_enable_streams,
 	.disable_streams        = csi2rx_disable_streams,
+	.get_frame_desc	= csi2rx_get_frame_desc,
 };
 
 static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
-- 
2.34.1

[PATCH v8 11/18] media: ti: j721e-csi2rx: add support for processing virtual channels

[Rishikesh Donadkar]

From: Jai Luthra <j-luthra@ti.com>

Use get_frame_desc() to get the frame desc from the connected source,
and use the provided virtual channel instead of hardcoded one.

get_frame_desc() returns the same information when called on each stream
start, so instead get the VCs for all the routed stream at first
stream start and cache this information in the driver.

get_frame_desc() works per stream, but as we don't support multiple
streams yet, we will just always use stream 0. If the source doesn't
support get_frame_desc(), fall back to the previous method of always
capturing virtual channel 0.

Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 5c4524bf42e6e..126a62fa2c4c4 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -32,6 +32,7 @@
 #define SHIM_DMACNTX_YUV422		GENMASK(27, 26)
 #define SHIM_DMACNTX_DUAL_PCK_CFG	BIT(24)
 #define SHIM_DMACNTX_SIZE		GENMASK(21, 20)
+#define SHIM_DMACNTX_VC			GENMASK(9, 6)
 #define SHIM_DMACNTX_FMT		GENMASK(5, 0)
 #define SHIM_DMACNTX_YUV422_MODE_11	3
 #define SHIM_DMACNTX_SIZE_8		0
@@ -110,6 +111,8 @@ struct ti_csi2rx_ctx {
 	struct media_pad		pad;
 	u32				sequence;
 	u32				idx;
+	u32				vc;
+	u32				stream;
 };
 
 struct ti_csi2rx_dev {
@@ -610,6 +613,7 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
 	}
 
 	reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
+	reg |= FIELD_PREP(SHIM_DMACNTX_VC, ctx->vc);
 
 	writel(reg, csi->shim + SHIM_DMACNTX(ctx->idx));
 
@@ -884,6 +888,32 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
 	}
 }
 
+static int ti_csi2rx_get_vc(struct ti_csi2rx_ctx *ctx)
+{
+	struct ti_csi2rx_dev *csi = ctx->csi;
+	struct v4l2_mbus_frame_desc fd;
+	struct media_pad *pad;
+	int ret, i;
+
+	pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
+	if (!pad)
+		return -ENODEV;
+
+	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, pad->index, &fd);
+	if (ret)
+		return ret;
+
+	if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
+		return -EINVAL;
+
+	for (i = 0; i < fd.num_entries; i++) {
+		if (ctx->stream == fd.entry[i].stream)
+			return fd.entry[i].bus.csi2.vc;
+	}
+
+	return -ENODEV;
+}
+
 static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 {
 	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
@@ -904,6 +934,14 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	if (ret)
 		goto err;
 
+	ret = ti_csi2rx_get_vc(ctx);
+	if (ret == -ENOIOCTLCMD)
+		ctx->vc = 0;
+	else if (ret < 0)
+		goto err;
+	else
+		ctx->vc = ret;
+
 	ti_csi2rx_setup_shim(ctx);
 
 	ctx->sequence = 0;
-- 
2.34.1

[PATCH v8 12/18] media: cadence: csi2rx: add multistream support

[Rishikesh Donadkar]

From: Jai Luthra <j-luthra@ti.com>

Cadence CSI-2 bridge IP supports capturing multiple virtual "streams"
of data over the same physical interface using MIPI Virtual Channels.

While the hardware IP supports usecases where streams coming in the sink
pad can be broadcasted to multiple source pads, the driver will need
significant re-architecture to make that possible. The two users of this
IP in mainline linux are TI Shim and StarFive JH7110 CAMSS, and both
have only integrated the first source pad i.e stream0 of this IP. So for
now keep it simple and only allow 1-to-1 mapping of streams from sink to
source, without any broadcasting.

Implement a fallback s_stream hook that internally calls enable_stream
on each source pad, for consumer drivers that don't use multi-stream
APIs to still work. The helper function v4l2_subdev_s_stream_helper()
form the v4l2 framework is not used here as it is meant only for the
subedvs that have a single source pad and this hardware IP supports
having multiple source pads.

Signed-off-by: Jai Luthra <j-luthra@ti.com>
Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 283 ++++++++++++++++---
 1 file changed, 236 insertions(+), 47 deletions(-)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 3688077fa8347..833bc134f17cb 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -135,6 +135,7 @@ struct csi2rx_priv {
 	struct phy			*dphy;
 
 	u8				num_pixels[CSI2RX_STREAMS_MAX];
+	u32				vc_select[CSI2RX_STREAMS_MAX];
 	u8				lanes[CSI2RX_LANES_MAX];
 	u8				num_lanes;
 	u8				max_lanes;
@@ -273,30 +274,43 @@ static void csi2rx_reset(struct csi2rx_priv *csi2rx)
 
 static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
 {
-	struct media_pad *src_pad =
-		&csi2rx->source_subdev->entity.pads[csi2rx->source_pad];
 	union phy_configure_opts opts = { };
 	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
-	struct v4l2_subdev_state *state;
 	struct v4l2_mbus_framefmt *framefmt;
+	struct v4l2_subdev_state *state;
 	const struct csi2rx_fmt *fmt;
+	int source_pad = csi2rx->source_pad;
+	struct media_pad *pad = &csi2rx->source_subdev->entity.pads[source_pad];
 	s64 link_freq;
 	int ret;
+	u32 bpp;
 
 	state = v4l2_subdev_get_locked_active_state(&csi2rx->subdev);
 
-	framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
-	if (!framefmt) {
-		dev_err(csi2rx->dev, "Did not find active sink format\n");
-		return -EINVAL;
-	}
+	/*
+	 * For multi-stream transmitters there is no single pixel rate.
+	 *
+	 * In multistream usecase pass bpp as 0 so that v4l2_get_link_freq()
+	 * returns an error if it falls back to V4L2_CID_PIXEL_RATE.
+	 */
+	if (state->routing.num_routes > 1) {
+		bpp = 0;
+	} else {
+		framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
+		if (!framefmt) {
+			dev_err(csi2rx->dev, "Did not find active sink format\n");
+			return -EINVAL;
+		}
 
-	fmt = csi2rx_get_fmt_by_code(framefmt->code);
+		fmt = csi2rx_get_fmt_by_code(framefmt->code);
+		bpp = fmt->bpp;
+	}
 
-	link_freq = v4l2_get_link_freq(src_pad,
-				       fmt->bpp, 2 * csi2rx->num_lanes);
-	if (link_freq < 0)
+	link_freq = v4l2_get_link_freq(pad, bpp, 2 * csi2rx->num_lanes);
+	if (link_freq < 0) {
+		dev_err(csi2rx->dev, "Unable to calculate link frequency\n");
 		return link_freq;
+	}
 
 	ret = phy_mipi_dphy_get_default_config_for_hsclk(link_freq,
 							 csi2rx->num_lanes, cfg);
@@ -394,11 +408,7 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 					  csi2rx->num_pixels[i]),
 		       csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
 
-		/*
-		 * Enable one virtual channel. When multiple virtual channels
-		 * are supported this will have to be changed.
-		 */
-		writel(CSI2RX_STREAM_DATA_CFG_VC_SELECT(0),
+		writel(csi2rx->vc_select[i],
 		       csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));
 
 		writel(CSI2RX_STREAM_CTRL_START,
@@ -486,18 +496,59 @@ static int csi2rx_log_status(struct v4l2_subdev *sd)
 	return 0;
 }
 
+static void csi2rx_update_vc_select(struct csi2rx_priv *csi2rx,
+				    struct v4l2_subdev_state *state)
+{
+	struct v4l2_mbus_frame_desc fd = {0};
+	struct v4l2_subdev_route *route;
+	unsigned int i;
+	int ret;
+
+	/* Capture VC=0 by default */
+	for (i = 0; i < CSI2RX_STREAMS_MAX; i++)
+		csi2rx->vc_select[i] = CSI2RX_STREAM_DATA_CFG_VC_SELECT(0);
+
+	ret = csi2rx_get_frame_desc_from_source(csi2rx, &fd);
+	if (ret || fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
+		dev_dbg(csi2rx->dev,
+			"Failed to get source frame desc, allowing only VC=0\n");
+		return;
+	}
+
+	/* If source provides per-stream VC info, use it to filter by VC */
+	memset(csi2rx->vc_select, 0, sizeof(csi2rx->vc_select));
+
+	for_each_active_route(&state->routing, route) {
+		u32 cdns_stream = route->source_pad - CSI2RX_PAD_SOURCE_STREAM0;
+
+		for (i = 0; i < fd.num_entries; i++) {
+			if (fd.entry[i].stream != route->sink_stream)
+				continue;
+
+			csi2rx->vc_select[cdns_stream] |=
+				CSI2RX_STREAM_DATA_CFG_VC_SELECT(fd.entry[i].bus.csi2.vc);
+		}
+	}
+}
+
 static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
 				 struct v4l2_subdev_state *state, u32 pad,
 				 u64 streams_mask)
 {
 	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+	u64 sink_streams;
 	int ret;
 
+	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
+						       CSI2RX_PAD_SINK,
+						       &streams_mask);
+
 	/*
 	 * If we're not the first users, there's no need to
 	 * enable the whole controller.
 	 */
 	if (!csi2rx->count) {
+		csi2rx_update_vc_select(csi2rx, state);
 		ret = csi2rx_start(csi2rx);
 		if (ret)
 			return ret;
@@ -505,10 +556,11 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
 
 	/* Start streaming on the source */
 	ret = v4l2_subdev_enable_streams(csi2rx->source_subdev, csi2rx->source_pad,
-					 BIT(0));
+					 sink_streams);
 	if (ret) {
 		dev_err(csi2rx->dev,
-			"Failed to start streams %d on subdev\n", 0);
+			"Failed to start streams %#llx on subdev\n",
+			sink_streams);
 		if (!csi2rx->count)
 			csi2rx_stop(csi2rx);
 		return ret;
@@ -523,9 +575,14 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
 				  u64 streams_mask)
 {
 	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+	u64 sink_streams;
+
+	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
+						       CSI2RX_PAD_SINK,
+						       &streams_mask);
 
 	if (v4l2_subdev_disable_streams(csi2rx->source_subdev,
-					csi2rx->source_pad, BIT(0))) {
+						 csi2rx->source_pad, sink_streams)) {
 		dev_err(csi2rx->dev, "Couldn't disable our subdev\n");
 	}
 
@@ -538,6 +595,36 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
 	return 0;
 }
 
+static int csi2rx_s_stream_fallback(struct v4l2_subdev *sd, int enable)
+{
+	struct v4l2_subdev_state *state;
+	struct v4l2_subdev_route *route;
+	u64 mask[CSI2RX_PAD_MAX] = {0};
+	int i, ret;
+
+	/* Find the stream mask on all source pads */
+	state = v4l2_subdev_lock_and_get_active_state(sd);
+	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
+		for_each_active_route(&state->routing, route) {
+			if (route->source_pad == i)
+				mask[i] |= BIT_ULL(route->source_stream);
+		}
+	}
+	v4l2_subdev_unlock_state(state);
+
+	/* Start streaming on each pad */
+	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
+		if (enable)
+			ret = v4l2_subdev_enable_streams(sd, i, mask[i]);
+		else
+			ret = v4l2_subdev_disable_streams(sd, i, mask[i]);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
 static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
 				 struct v4l2_subdev_state *state,
 				 struct v4l2_subdev_mbus_code_enum *code_enum)
@@ -550,12 +637,56 @@ static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
 	return 0;
 }
 
+static int _csi2rx_set_routing(struct v4l2_subdev *subdev,
+			       struct v4l2_subdev_state *state,
+			       struct v4l2_subdev_krouting *routing)
+{
+	static const struct v4l2_mbus_framefmt format = {
+		.width = 640,
+		.height = 480,
+		.code = MEDIA_BUS_FMT_UYVY8_1X16,
+		.field = V4L2_FIELD_NONE,
+		.colorspace = V4L2_COLORSPACE_SRGB,
+		.ycbcr_enc = V4L2_YCBCR_ENC_601,
+		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
+		.xfer_func = V4L2_XFER_FUNC_SRGB,
+	};
+	int ret;
+
+	if (routing->num_routes > V4L2_FRAME_DESC_ENTRY_MAX)
+		return -EINVAL;
+
+	ret = v4l2_subdev_routing_validate(subdev, routing,
+					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
+	if (ret)
+		return ret;
+
+	return v4l2_subdev_set_routing_with_fmt(subdev, state, routing, &format);
+}
+
+static int csi2rx_set_routing(struct v4l2_subdev *subdev,
+			      struct v4l2_subdev_state *state,
+			      enum v4l2_subdev_format_whence which,
+			      struct v4l2_subdev_krouting *routing)
+{
+	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+	int ret;
+
+	if (which == V4L2_SUBDEV_FORMAT_ACTIVE && csi2rx->count)
+		return -EBUSY;
+
+	ret = _csi2rx_set_routing(subdev, state, routing);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
 			  struct v4l2_subdev_state *state,
 			  struct v4l2_subdev_format *format)
 {
 	struct v4l2_mbus_framefmt *fmt;
-	unsigned int i;
 
 	/* No transcoding, source and sink formats must match. */
 	if (format->pad != CSI2RX_PAD_SINK)
@@ -567,14 +698,16 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
 	format->format.field = V4L2_FIELD_NONE;
 
 	/* Set sink format */
-	fmt = v4l2_subdev_state_get_format(state, format->pad);
+	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
 	*fmt = format->format;
 
-	/* Propagate to source formats */
-	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
-		fmt = v4l2_subdev_state_get_format(state, i);
-		*fmt = format->format;
-	}
+	/* Propagate to source format */
+	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
+							   format->stream);
+	if (!fmt)
+		return -EINVAL;
+
+	*fmt = format->format;
 
 	return 0;
 }
@@ -582,21 +715,22 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
 static int csi2rx_init_state(struct v4l2_subdev *subdev,
 			     struct v4l2_subdev_state *state)
 {
-	struct v4l2_subdev_format format = {
-		.pad = CSI2RX_PAD_SINK,
-		.format = {
-			.width = 640,
-			.height = 480,
-			.code = MEDIA_BUS_FMT_UYVY8_1X16,
-			.field = V4L2_FIELD_NONE,
-			.colorspace = V4L2_COLORSPACE_SRGB,
-			.ycbcr_enc = V4L2_YCBCR_ENC_601,
-			.quantization = V4L2_QUANTIZATION_LIM_RANGE,
-			.xfer_func = V4L2_XFER_FUNC_SRGB,
+	struct v4l2_subdev_route routes[] = {
+		{
+			.sink_pad = CSI2RX_PAD_SINK,
+			.sink_stream = 0,
+			.source_pad = CSI2RX_PAD_SOURCE_STREAM0,
+			.source_stream = 0,
+			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
 		},
 	};
 
-	return csi2rx_set_fmt(subdev, state, &format);
+	struct v4l2_subdev_krouting routing = {
+		.num_routes = ARRAY_SIZE(routes),
+		.routes = routes,
+	};
+
+	return _csi2rx_set_routing(subdev, state, &routing);
 }
 
 int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
@@ -630,17 +764,70 @@ static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
 				 struct v4l2_mbus_frame_desc *fd)
 {
 	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+	struct v4l2_mbus_frame_desc source_fd = {0};
+	struct v4l2_subdev_route *route;
+	struct v4l2_subdev_state *state;
+	int ret;
+
+	ret = csi2rx_get_frame_desc_from_source(csi2rx, &source_fd);
+	if (ret)
+		return ret;
+
+	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
+
+	state = v4l2_subdev_lock_and_get_active_state(subdev);
+
+	for_each_active_route(&state->routing, route) {
+		struct v4l2_mbus_frame_desc_entry *source_entry = NULL;
+		unsigned int i;
+
+		if (route->source_pad != pad)
+			continue;
+
+		for (i = 0; i < source_fd.num_entries; i++) {
+			if (source_fd.entry[i].stream == route->sink_stream) {
+				source_entry = &source_fd.entry[i];
+				break;
+			}
+		}
+
+		if (!source_entry) {
+			dev_err(csi2rx->dev,
+				"Failed to find stream from source frame desc\n");
+			ret = -EPIPE;
+			goto err_missing_stream;
+		}
+
+		fd->entry[fd->num_entries].stream = route->source_stream;
+		fd->entry[fd->num_entries].flags = source_entry->flags;
+		fd->entry[fd->num_entries].length = source_entry->length;
+		fd->entry[fd->num_entries].pixelcode = source_entry->pixelcode;
+		fd->entry[fd->num_entries].bus.csi2.vc =
+			source_entry->bus.csi2.vc;
+		fd->entry[fd->num_entries].bus.csi2.dt =
+			source_entry->bus.csi2.dt;
+
+		fd->num_entries++;
+	}
+
+err_missing_stream:
+	v4l2_subdev_unlock_state(state);
 
-	return csi2rx_get_frame_desc_from_source(csi2rx, fd);
+	return ret;
 }
 
 static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
-	.enum_mbus_code	= csi2rx_enum_mbus_code,
-	.get_fmt	= v4l2_subdev_get_fmt,
-	.set_fmt	= csi2rx_set_fmt,
-	.enable_streams         = csi2rx_enable_streams,
-	.disable_streams        = csi2rx_disable_streams,
-	.get_frame_desc	= csi2rx_get_frame_desc,
+	.enum_mbus_code		= csi2rx_enum_mbus_code,
+	.get_fmt		= v4l2_subdev_get_fmt,
+	.set_fmt		= csi2rx_set_fmt,
+	.get_frame_desc		= csi2rx_get_frame_desc,
+	.set_routing		= csi2rx_set_routing,
+	.enable_streams		= csi2rx_enable_streams,
+	.disable_streams	= csi2rx_disable_streams,
+};
+
+static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
+	.s_stream	= csi2rx_s_stream_fallback,
 };
 
 static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
@@ -649,6 +836,7 @@ static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
 
 static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
 	.core		= &csi2rx_core_ops,
+	.video		= &csi2rx_video_ops,
 	.pad		= &csi2rx_pad_ops,
 };
 
@@ -876,7 +1064,8 @@ static int csi2rx_probe(struct platform_device *pdev)
 	csi2rx->pads[CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
 	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
 		csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
-	csi2rx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	csi2rx->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE |
+		V4L2_SUBDEV_FL_STREAMS;
 	csi2rx->subdev.entity.ops = &csi2rx_media_ops;
 
 	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,
-- 
2.34.1

[PATCH v8 13/18] media: ti: j721e-csi2rx: add multistream support

[Rishikesh Donadkar]

From: Jai Luthra <j-luthra@ti.com>

Each CSI2 stream can be multiplexed into 4 independent streams, each
identified by its virtual channel number and data type. The incoming
data from these streams can be filtered on the basis of either the
virtual channel or the data type.

To capture this multiplexed stream, the application needs to tell
the driver how it wants to route the data. It needs to specify
which context should process which stream. This is done via the
new routing APIs.

Add ioctls to accept routing information from the application and save
that in the driver. This can be used when starting streaming on a
context to determine which route and consequently which virtual channel
it should process.

De-assert the pixel interface reset on first start_streaming() and assert
it on the last stop_streaming().

Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 224 ++++++++++++++----
 1 file changed, 179 insertions(+), 45 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 126a62fa2c4c4..c8e0e761f2802 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -103,6 +103,7 @@ struct ti_csi2rx_dev;
 
 struct ti_csi2rx_ctx {
 	struct ti_csi2rx_dev		*csi;
+	struct v4l2_subdev_route        *route;
 	struct video_device		vdev;
 	struct vb2_queue		vidq;
 	struct mutex			mutex; /* To serialize ioctls. */
@@ -136,6 +137,7 @@ struct ti_csi2rx_dev {
 		dma_addr_t		paddr;
 		size_t			len;
 	} drain;
+	bool                            vc_cached;
 };
 
 static inline struct ti_csi2rx_dev *to_csi2rx_dev(struct v4l2_subdev *sd)
@@ -143,17 +145,6 @@ static inline struct ti_csi2rx_dev *to_csi2rx_dev(struct v4l2_subdev *sd)
 	return container_of(sd, struct ti_csi2rx_dev, subdev);
 }
 
-static const struct v4l2_mbus_framefmt ti_csi2rx_default_fmt = {
-	.width = 640,
-	.height = 480,
-	.code = MEDIA_BUS_FMT_UYVY8_1X16,
-	.field = V4L2_FIELD_NONE,
-	.colorspace = V4L2_COLORSPACE_SRGB,
-	.ycbcr_enc = V4L2_YCBCR_ENC_601,
-	.quantization = V4L2_QUANTIZATION_LIM_RANGE,
-	.xfer_func = V4L2_XFER_FUNC_SRGB,
-};
-
 static const struct ti_csi2rx_fmt ti_csi2rx_formats[] = {
 	{
 		.fourcc			= V4L2_PIX_FMT_YUYV,
@@ -566,8 +557,10 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
 	fmt = find_format_by_fourcc(ctx->v_fmt.fmt.pix.pixelformat);
 
 	/* De-assert the pixel interface reset. */
-	reg = SHIM_CNTL_PIX_RST;
-	writel(reg, csi->shim + SHIM_CNTL);
+	if (!csi->enable_count) {
+		reg = SHIM_CNTL_PIX_RST;
+		writel(reg, csi->shim + SHIM_CNTL);
+	}
 
 	/* Negotiate pixel count from the source */
 	ti_csi2rx_request_max_ppc(csi);
@@ -888,30 +881,80 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
 	}
 }
 
+static int ti_csi2rx_get_route(struct ti_csi2rx_ctx *ctx)
+{
+	struct ti_csi2rx_dev *csi = ctx->csi;
+	struct media_pad *pad;
+	struct v4l2_subdev_state *state;
+	struct v4l2_subdev_route *r;
+
+	/* Get the source pad connected to this ctx */
+	pad = media_entity_remote_source_pad_unique(ctx->pad.entity);
+	if (!pad) {
+		dev_err(csi->dev, "No pad connected to ctx %d\n", ctx->idx);
+		return -ENODEV;
+	}
+
+	state = v4l2_subdev_lock_and_get_active_state(&csi->subdev);
+
+	for_each_active_route(&state->routing, r) {
+		if (!(r->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE))
+			continue;
+		if (r->source_pad != pad->index)
+			continue;
+
+		ctx->route = r;
+	}
+
+	v4l2_subdev_unlock_state(state);
+
+	if (!ctx->route)
+		return -ENODEV;
+
+	return 0;
+}
+
 static int ti_csi2rx_get_vc(struct ti_csi2rx_ctx *ctx)
 {
 	struct ti_csi2rx_dev *csi = ctx->csi;
+	struct ti_csi2rx_ctx *curr_ctx;
 	struct v4l2_mbus_frame_desc fd;
-	struct media_pad *pad;
-	int ret, i;
+	struct media_pad *source_pad;
+	struct v4l2_subdev_route *curr_route;
+	int ret;
+	unsigned int i, j;
 
-	pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
-	if (!pad)
+	/* Get the frame desc form source */
+	source_pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
+	if (!source_pad)
 		return -ENODEV;
 
-	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, pad->index, &fd);
+	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, source_pad->index, &fd);
 	if (ret)
 		return ret;
 
 	if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
 		return -EINVAL;
 
-	for (i = 0; i < fd.num_entries; i++) {
-		if (ctx->stream == fd.entry[i].stream)
-			return fd.entry[i].bus.csi2.vc;
+	for (i = 0; i < csi->num_ctx; i++) {
+		curr_ctx = &csi->ctx[i];
+
+		/* Capture VC 0 by default */
+		curr_ctx->vc = 0;
+
+		ret = ti_csi2rx_get_route(curr_ctx);
+		if (ret)
+			continue;
+
+		curr_route = curr_ctx->route;
+		curr_ctx->stream = curr_route->sink_stream;
+
+		for (j = 0; j < fd.num_entries; j++)
+			if (curr_ctx->stream == fd.entry[j].stream)
+				curr_ctx->vc = fd.entry[j].bus.csi2.vc;
 	}
 
-	return -ENODEV;
+	return 0;
 }
 
 static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
@@ -934,13 +977,24 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	if (ret)
 		goto err;
 
-	ret = ti_csi2rx_get_vc(ctx);
-	if (ret == -ENOIOCTLCMD)
-		ctx->vc = 0;
-	else if (ret < 0)
+	/* If no stream is routed to this ctx, exit early */
+	ret = ti_csi2rx_get_route(ctx);
+	if (ret)
 		goto err;
-	else
-		ctx->vc = ret;
+
+	/* Get the VC for all enabled ctx on first stream start */
+	mutex_lock(&csi->mutex);
+	if (!csi->vc_cached) {
+		ret = ti_csi2rx_get_vc(ctx);
+		if (ret == -ENOIOCTLCMD) {
+			ctx->vc = 0;
+		} else if (ret < 0) {
+			mutex_unlock(&csi->mutex);
+			goto err;
+		}
+		csi->vc_cached = true;
+	}
+	mutex_unlock(&csi->mutex);
 
 	ti_csi2rx_setup_shim(ctx);
 
@@ -960,8 +1014,9 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	dma->state = TI_CSI2RX_DMA_ACTIVE;
 	spin_unlock_irqrestore(&dma->lock, flags);
 
+	/* Start stream 0, we don't allow multiple streams on the source pad */
 	ret = v4l2_subdev_enable_streams(&csi->subdev,
-					 TI_CSI2RX_PAD_FIRST_SOURCE,
+					 TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
 					 BIT(0));
 	if (ret)
 		goto err_dma;
@@ -985,17 +1040,26 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 	struct ti_csi2rx_dev *csi = ctx->csi;
 	int ret;
 
-	video_device_pipeline_stop(&ctx->vdev);
+	mutex_lock(&csi->mutex);
 
-	writel(0, csi->shim + SHIM_CNTL);
 	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
 
+	/* assert pixel reset to prevent stale data */
+	if (csi->enable_count == 1) {
+		writel(0, csi->shim + SHIM_CNTL);
+		csi->vc_cached = false;
+	}
+
+	video_device_pipeline_stop(&ctx->vdev);
+
 	ret = v4l2_subdev_disable_streams(&csi->subdev,
-					  TI_CSI2RX_PAD_FIRST_SOURCE,
+					  TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
 					  BIT(0));
 	if (ret)
 		dev_err(csi->dev, "Failed to stop subdev stream\n");
 
+	mutex_unlock(&csi->mutex);
+
 	ti_csi2rx_stop_dma(ctx);
 	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
 }
@@ -1038,25 +1102,84 @@ static int ti_csi2rx_sd_set_fmt(struct v4l2_subdev *sd,
 	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
 	*fmt = format->format;
 
-	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE,
-					   format->stream);
+	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
+							   format->stream);
+	if (!fmt)
+		return -EINVAL;
+
 	*fmt = format->format;
 
 	return 0;
 }
 
-static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
-				   struct v4l2_subdev_state *state)
+static int _ti_csi2rx_sd_set_routing(struct v4l2_subdev *sd,
+				     struct v4l2_subdev_state *state,
+				     struct v4l2_subdev_krouting *routing)
 {
-	struct v4l2_mbus_framefmt *fmt;
+	int ret;
 
-	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_SINK);
-	*fmt = ti_csi2rx_default_fmt;
+	const struct v4l2_mbus_framefmt format = {
+		.width = 640,
+		.height = 480,
+		.code = MEDIA_BUS_FMT_UYVY8_1X16,
+		.field = V4L2_FIELD_NONE,
+		.colorspace = V4L2_COLORSPACE_SRGB,
+		.ycbcr_enc = V4L2_YCBCR_ENC_601,
+		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
+		.xfer_func = V4L2_XFER_FUNC_SRGB,
+	};
 
-	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE);
-	*fmt = ti_csi2rx_default_fmt;
+	ret = v4l2_subdev_routing_validate(sd, routing,
+					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1 |
+					   V4L2_SUBDEV_ROUTING_NO_SOURCE_MULTIPLEXING);
 
-	return 0;
+	if (ret)
+		return ret;
+
+	/* Only stream ID 0 allowed on source pads */
+	for (unsigned int i = 0; i < routing->num_routes; ++i) {
+		const struct v4l2_subdev_route *route = &routing->routes[i];
+
+		if (route->source_stream != 0)
+			return -EINVAL;
+	}
+
+	ret = v4l2_subdev_set_routing_with_fmt(sd, state, routing, &format);
+
+	return ret;
+}
+
+static int ti_csi2rx_sd_set_routing(struct v4l2_subdev *sd,
+				    struct v4l2_subdev_state *state,
+				    enum v4l2_subdev_format_whence which,
+				    struct v4l2_subdev_krouting *routing)
+{
+	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
+
+	if (csi->enable_count > 0)
+		return -EBUSY;
+
+	return _ti_csi2rx_sd_set_routing(sd, state, routing);
+}
+
+static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_state *state)
+{
+	struct v4l2_subdev_route routes[] = { {
+		.sink_pad = 0,
+		.sink_stream = 0,
+		.source_pad = TI_CSI2RX_PAD_FIRST_SOURCE,
+		.source_stream = 0,
+		.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
+	} };
+
+	struct v4l2_subdev_krouting routing = {
+		.num_routes = 1,
+		.routes = routes,
+	};
+
+	/* Initialize routing to single route to the fist source pad */
+	return _ti_csi2rx_sd_set_routing(sd, state, &routing);
 }
 
 static int ti_csi2rx_sd_enable_streams(struct v4l2_subdev *sd,
@@ -1065,14 +1188,18 @@ static int ti_csi2rx_sd_enable_streams(struct v4l2_subdev *sd,
 {
 	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
 	struct media_pad *remote_pad;
+	u64 sink_streams;
 	int ret = 0;
 
 	remote_pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
 	if (!remote_pad)
 		return -ENODEV;
+	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
+						       TI_CSI2RX_PAD_SINK,
+						       &streams_mask);
 
 	ret = v4l2_subdev_enable_streams(csi->source, remote_pad->index,
-					 BIT(0));
+					 sink_streams);
 	if (ret)
 		return ret;
 
@@ -1087,17 +1214,21 @@ static int ti_csi2rx_sd_disable_streams(struct v4l2_subdev *sd,
 {
 	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
 	struct media_pad *remote_pad;
+	u64 sink_streams;
 	int ret = 0;
 
 	remote_pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
 	if (!remote_pad)
 		return -ENODEV;
+	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
+						       TI_CSI2RX_PAD_SINK,
+						       &streams_mask);
 
 	if (csi->enable_count == 0)
 		return -EINVAL;
 
 	ret = v4l2_subdev_disable_streams(csi->source, remote_pad->index,
-					  BIT(0));
+					  sink_streams);
 	if (!ret)
 		--csi->enable_count;
 
@@ -1106,6 +1237,7 @@ static int ti_csi2rx_sd_disable_streams(struct v4l2_subdev *sd,
 
 static const struct v4l2_subdev_pad_ops ti_csi2rx_subdev_pad_ops = {
 	.enum_mbus_code	= ti_csi2rx_enum_mbus_code,
+	.set_routing = ti_csi2rx_sd_set_routing,
 	.get_fmt = v4l2_subdev_get_fmt,
 	.set_fmt = ti_csi2rx_sd_set_fmt,
 	.enable_streams = ti_csi2rx_sd_enable_streams,
@@ -1284,7 +1416,7 @@ static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
 	v4l2_subdev_init(sd, &ti_csi2rx_subdev_ops);
 	sd->internal_ops = &ti_csi2rx_internal_ops;
 	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
-	sd->flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
+	sd->flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_STREAMS;
 	strscpy(sd->name, dev_name(csi->dev), sizeof(sd->name));
 	sd->dev = csi->dev;
 	sd->entity.ops = &ti_csi2rx_subdev_entity_ops;
@@ -1347,6 +1479,8 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
 
 	ti_csi2rx_fill_fmt(fmt, &ctx->v_fmt);
 
+	ctx->route = NULL;
+
 	ctx->pad.flags = MEDIA_PAD_FL_SINK;
 	vdev->entity.ops = &ti_csi2rx_video_entity_ops;
 	ret = media_entity_pads_init(&ctx->vdev.entity, 1, &ctx->pad);
-- 
2.34.1

[PATCH v8 14/18] media: ti: j721e-csi2rx: Submit all available buffers

[Rishikesh Donadkar]

From: Jai Luthra <j-luthra@ti.com>

We already make sure to submit all available buffers to DMA in each DMA
completion callback.

Move that logic in a separate function, and use it during stream start
as well, as most application queue all their buffers before stream on.

Signed-off-by: Jai Luthra <j-luthra@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 45 ++++++++++---------
 1 file changed, 25 insertions(+), 20 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index c8e0e761f2802..e439e9814c74d 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -672,11 +672,32 @@ static int ti_csi2rx_drain_dma(struct ti_csi2rx_ctx *ctx)
 	return ret;
 }
 
+static int ti_csi2rx_dma_submit_pending(struct ti_csi2rx_ctx *ctx)
+{
+	struct ti_csi2rx_dma *dma = &ctx->dma;
+	struct ti_csi2rx_buffer *buf;
+	int ret = 0;
+
+	/* If there are more buffers to process then start their transfer. */
+	while (!list_empty(&dma->queue)) {
+		buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
+		ret = ti_csi2rx_start_dma(ctx, buf);
+		if (ret) {
+			dev_err(ctx->csi->dev,
+				"Failed to queue the next buffer for DMA\n");
+			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+			list_del(&buf->list);
+		} else {
+			list_move_tail(&buf->list, &dma->submitted);
+		}
+	}
+	return ret;
+}
+
 static void ti_csi2rx_dma_callback(void *param)
 {
 	struct ti_csi2rx_buffer *buf = param;
 	struct ti_csi2rx_ctx *ctx = buf->ctx;
-	struct ti_csi2rx_dev *csi = ctx->csi;
 	struct ti_csi2rx_dma *dma = &ctx->dma;
 	unsigned long flags;
 
@@ -693,18 +714,7 @@ static void ti_csi2rx_dma_callback(void *param)
 	vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
 	list_del(&buf->list);
 
-	/* If there are more buffers to process then start their transfer. */
-	while (!list_empty(&dma->queue)) {
-		buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
-
-		if (ti_csi2rx_start_dma(ctx, buf)) {
-			dev_err(csi->dev, "Failed to queue the next buffer for DMA\n");
-			list_del(&buf->list);
-			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
-		} else {
-			list_move_tail(&buf->list, &dma->submitted);
-		}
-	}
+	ti_csi2rx_dma_submit_pending(ctx);
 
 	if (list_empty(&dma->submitted))
 		dma->state = TI_CSI2RX_DMA_IDLE;
@@ -962,7 +972,6 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
 	struct ti_csi2rx_dev *csi = ctx->csi;
 	struct ti_csi2rx_dma *dma = &ctx->dma;
-	struct ti_csi2rx_buffer *buf;
 	unsigned long flags;
 	int ret = 0;
 
@@ -1001,16 +1010,13 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	ctx->sequence = 0;
 
 	spin_lock_irqsave(&dma->lock, flags);
-	buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
 
-	ret = ti_csi2rx_start_dma(ctx, buf);
+	ret = ti_csi2rx_dma_submit_pending(ctx);
 	if (ret) {
-		dev_err(csi->dev, "Failed to start DMA: %d\n", ret);
 		spin_unlock_irqrestore(&dma->lock, flags);
-		goto err_pipeline;
+		goto err_dma;
 	}
 
-	list_move_tail(&buf->list, &dma->submitted);
 	dma->state = TI_CSI2RX_DMA_ACTIVE;
 	spin_unlock_irqrestore(&dma->lock, flags);
 
@@ -1025,7 +1031,6 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 
 err_dma:
 	ti_csi2rx_stop_dma(ctx);
-err_pipeline:
 	video_device_pipeline_stop(&ctx->vdev);
 	writel(0, csi->shim + SHIM_CNTL);
 	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
-- 
2.34.1

[PATCH v8 15/18] media: ti: j721e-csi2rx: Change the drain architecture for multistream

[Rishikesh Donadkar]

On buffer starvation the DMA is marked IDLE, and the stale data in the
internal FIFOs gets drained only on the next VIDIOC_QBUF call from the
userspace. This approach works fine for a single stream case.

But in multistream scenarios, buffer starvation for one stream i.e. one
virtual channel, can block the shared HW FIFO of the CSI2RX IP. This can
stall the pipeline for all other virtual channels, even if buffers are
available for them.

This patch introduces a new architecture, that continuously drains data
from the shared HW FIFO into a small (32KiB) buffer if no buffers are made
available to the driver from the userspace. This ensures independence
between different streams, where a slower downstream element for one
camera does not block streaming for other cameras.

Additionally, after a drain is done for a VC, the next frame will be a
partial frame, as a portion of its data will have already been drained
before a valid buffer is queued by user space to the driver.

Use wait for completion barrier to make sure the shared hardware FIFO
is cleared of the data at the end of stream after the source has stopped
sending data.

Reviewed-by: Jai Luthra <jai.luthra@ideasonboard.com>
Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 112 ++++++++----------
 1 file changed, 50 insertions(+), 62 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index e439e9814c74d..528041ee78cf3 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -82,7 +82,6 @@ struct ti_csi2rx_buffer {
 
 enum ti_csi2rx_dma_state {
 	TI_CSI2RX_DMA_STOPPED,	/* Streaming not started yet. */
-	TI_CSI2RX_DMA_IDLE,	/* Streaming but no pending DMA operation. */
 	TI_CSI2RX_DMA_ACTIVE,	/* Streaming and pending DMA operation. */
 };
 
@@ -110,6 +109,7 @@ struct ti_csi2rx_ctx {
 	struct v4l2_format		v_fmt;
 	struct ti_csi2rx_dma		dma;
 	struct media_pad		pad;
+	struct completion		drain_complete;
 	u32				sequence;
 	u32				idx;
 	u32				vc;
@@ -251,6 +251,10 @@ static const struct ti_csi2rx_fmt ti_csi2rx_formats[] = {
 static int ti_csi2rx_start_dma(struct ti_csi2rx_ctx *ctx,
 			       struct ti_csi2rx_buffer *buf);
 
+/* Forward declarations needed by ti_csi2rx_drain_callback. */
+static int ti_csi2rx_drain_dma(struct ti_csi2rx_ctx *ctx);
+static int ti_csi2rx_dma_submit_pending(struct ti_csi2rx_ctx *ctx);
+
 static const struct ti_csi2rx_fmt *find_format_by_fourcc(u32 pixelformat)
 {
 	unsigned int i;
@@ -617,9 +621,32 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
 
 static void ti_csi2rx_drain_callback(void *param)
 {
-	struct completion *drain_complete = param;
+	struct ti_csi2rx_ctx *ctx = param;
+	struct ti_csi2rx_dma *dma = &ctx->dma;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dma->lock, flags);
+
+	if (dma->state == TI_CSI2RX_DMA_STOPPED) {
+		complete(&ctx->drain_complete);
+		spin_unlock_irqrestore(&dma->lock, flags);
+		return;
+	}
 
-	complete(drain_complete);
+	/*
+	 * If dma->queue is empty, it indicates that no buffer has been
+	 * provided by user space. In this case, initiate a transactions
+	 * to drain the DMA. Since one drain of size DRAIN_BUFFER_SIZE
+	 * will be done here, the subsequent frame will be a
+	 * partial frame, with a size of frame_size - DRAIN_BUFFER_SIZE
+	 */
+	if (list_empty(&dma->queue)) {
+		if (ti_csi2rx_drain_dma(ctx))
+			dev_warn(ctx->csi->dev, "DMA drain failed\n");
+	} else {
+		ti_csi2rx_dma_submit_pending(ctx);
+	}
+	spin_unlock_irqrestore(&dma->lock, flags);
 }
 
 /*
@@ -637,12 +664,9 @@ static int ti_csi2rx_drain_dma(struct ti_csi2rx_ctx *ctx)
 {
 	struct ti_csi2rx_dev *csi = ctx->csi;
 	struct dma_async_tx_descriptor *desc;
-	struct completion drain_complete;
 	dma_cookie_t cookie;
 	int ret;
 
-	init_completion(&drain_complete);
-
 	desc = dmaengine_prep_slave_single(ctx->dma.chan, csi->drain.paddr,
 					   csi->drain.len, DMA_DEV_TO_MEM,
 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
@@ -652,7 +676,7 @@ static int ti_csi2rx_drain_dma(struct ti_csi2rx_ctx *ctx)
 	}
 
 	desc->callback = ti_csi2rx_drain_callback;
-	desc->callback_param = &drain_complete;
+	desc->callback_param = ctx;
 
 	cookie = dmaengine_submit(desc);
 	ret = dma_submit_error(cookie);
@@ -661,13 +685,6 @@ static int ti_csi2rx_drain_dma(struct ti_csi2rx_ctx *ctx)
 
 	dma_async_issue_pending(ctx->dma.chan);
 
-	if (!wait_for_completion_timeout(&drain_complete,
-					 msecs_to_jiffies(DRAIN_TIMEOUT_MS))) {
-		dmaengine_terminate_sync(ctx->dma.chan);
-		dev_dbg(csi->dev, "DMA transfer timed out for drain buffer\n");
-		ret = -ETIMEDOUT;
-		goto out;
-	}
 out:
 	return ret;
 }
@@ -716,9 +733,11 @@ static void ti_csi2rx_dma_callback(void *param)
 
 	ti_csi2rx_dma_submit_pending(ctx);
 
-	if (list_empty(&dma->submitted))
-		dma->state = TI_CSI2RX_DMA_IDLE;
-
+	if (list_empty(&dma->submitted)) {
+		if (ti_csi2rx_drain_dma(ctx))
+			dev_warn(ctx->csi->dev,
+				 "DMA drain failed on one of the transactions\n");
+	}
 	spin_unlock_irqrestore(&dma->lock, flags);
 }
 
@@ -754,6 +773,7 @@ static int ti_csi2rx_start_dma(struct ti_csi2rx_ctx *ctx,
 static void ti_csi2rx_stop_dma(struct ti_csi2rx_ctx *ctx)
 {
 	struct ti_csi2rx_dma *dma = &ctx->dma;
+	struct ti_csi2rx_dev *csi = ctx->csi;
 	enum ti_csi2rx_dma_state state;
 	unsigned long flags;
 	int ret;
@@ -763,6 +783,8 @@ static void ti_csi2rx_stop_dma(struct ti_csi2rx_ctx *ctx)
 	dma->state = TI_CSI2RX_DMA_STOPPED;
 	spin_unlock_irqrestore(&dma->lock, flags);
 
+	init_completion(&ctx->drain_complete);
+
 	if (state != TI_CSI2RX_DMA_STOPPED) {
 		/*
 		 * Normal DMA termination does not clean up pending data on
@@ -771,11 +793,20 @@ static void ti_csi2rx_stop_dma(struct ti_csi2rx_ctx *ctx)
 		 * enforced before terminating DMA.
 		 */
 		ret = ti_csi2rx_drain_dma(ctx);
-		if (ret && ret != -ETIMEDOUT)
+		if (ret)
 			dev_warn(ctx->csi->dev,
 				 "Failed to drain DMA. Next frame might be bogus\n");
 	}
 
+	/* We wait for the drain to complete so that the stream stops
+	 * cleanly, making sure the shared hardware FIFO is cleared of
+	 * data from the current stream. No more data will be coming from
+	 * the source after this.
+	 */
+	if (!wait_for_completion_timeout(&ctx->drain_complete,
+					 msecs_to_jiffies(DRAIN_TIMEOUT_MS)))
+		dev_dbg(csi->dev, "DMA transfer timed out for drain buffer\n");
+
 	ret = dmaengine_terminate_sync(ctx->dma.chan);
 	if (ret)
 		dev_err(ctx->csi->dev, "Failed to stop DMA: %d\n", ret);
@@ -838,57 +869,14 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
 	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
 	struct ti_csi2rx_buffer *buf;
 	struct ti_csi2rx_dma *dma = &ctx->dma;
-	bool restart_dma = false;
 	unsigned long flags = 0;
-	int ret;
 
 	buf = container_of(vb, struct ti_csi2rx_buffer, vb.vb2_buf);
 	buf->ctx = ctx;
 
 	spin_lock_irqsave(&dma->lock, flags);
-	/*
-	 * Usually the DMA callback takes care of queueing the pending buffers.
-	 * But if DMA has stalled due to lack of buffers, restart it now.
-	 */
-	if (dma->state == TI_CSI2RX_DMA_IDLE) {
-		/*
-		 * Do not restart DMA with the lock held because
-		 * ti_csi2rx_drain_dma() might block for completion.
-		 * There won't be a race on queueing DMA anyway since the
-		 * callback is not being fired.
-		 */
-		restart_dma = true;
-		dma->state = TI_CSI2RX_DMA_ACTIVE;
-	} else {
-		list_add_tail(&buf->list, &dma->queue);
-	}
+	list_add_tail(&buf->list, &dma->queue);
 	spin_unlock_irqrestore(&dma->lock, flags);
-
-	if (restart_dma) {
-		/*
-		 * Once frames start dropping, some data gets stuck in the DMA
-		 * pipeline somewhere. So the first DMA transfer after frame
-		 * drops gives a partial frame. This is obviously not useful to
-		 * the application and will only confuse it. Issue a DMA
-		 * transaction to drain that up.
-		 */
-		ret = ti_csi2rx_drain_dma(ctx);
-		if (ret && ret != -ETIMEDOUT)
-			dev_warn(ctx->csi->dev,
-				 "Failed to drain DMA. Next frame might be bogus\n");
-
-		spin_lock_irqsave(&dma->lock, flags);
-		ret = ti_csi2rx_start_dma(ctx, buf);
-		if (ret) {
-			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
-			dma->state = TI_CSI2RX_DMA_IDLE;
-			spin_unlock_irqrestore(&dma->lock, flags);
-			dev_err(ctx->csi->dev, "Failed to start DMA: %d\n", ret);
-		} else {
-			list_add_tail(&buf->list, &dma->submitted);
-			spin_unlock_irqrestore(&dma->lock, flags);
-		}
-	}
 }
 
 static int ti_csi2rx_get_route(struct ti_csi2rx_ctx *ctx)
-- 
2.34.1

[PATCH v8 16/18] media: cadence: csi2rx: Support runtime PM

[Rishikesh Donadkar]

From: Changhuang Liang <changhuang.liang@starfivetech.com>

Use runtime power management hooks to save power when CSI-RX is not in
use.

Signed-off-by: Changhuang Liang <changhuang.liang@starfivetech.com>
Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 drivers/media/platform/cadence/Kconfig       |   1 +
 drivers/media/platform/cadence/cdns-csi2rx.c | 129 ++++++++++++-------
 2 files changed, 83 insertions(+), 47 deletions(-)

diff --git a/drivers/media/platform/cadence/Kconfig b/drivers/media/platform/cadence/Kconfig
index 1aa608c00dbce..ea85ef82760e6 100644
--- a/drivers/media/platform/cadence/Kconfig
+++ b/drivers/media/platform/cadence/Kconfig
@@ -5,6 +5,7 @@ comment "Cadence media platform drivers"
 config VIDEO_CADENCE_CSI2RX
 	tristate "Cadence MIPI-CSI2 RX Controller"
 	depends on VIDEO_DEV
+	depends on PM
 	select MEDIA_CONTROLLER
 	select VIDEO_V4L2_SUBDEV_API
 	select V4L2_FWNODE
diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 833bc134f17cb..6447c225ba354 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -337,11 +337,6 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 	u32 reg;
 	int ret;
 
-	ret = clk_prepare_enable(csi2rx->p_clk);
-	if (ret)
-		return ret;
-
-	reset_control_deassert(csi2rx->p_rst);
 	csi2rx_reset(csi2rx);
 
 	if (csi2rx->error_irq >= 0)
@@ -382,7 +377,7 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 		if (ret) {
 			dev_err(csi2rx->dev,
 				"Failed to configure external DPHY: %d\n", ret);
-			goto err_disable_pclk;
+			return ret;
 		}
 	}
 
@@ -397,12 +392,6 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 	 * hence the reference counting.
 	 */
 	for (i = 0; i < csi2rx->max_streams; i++) {
-		ret = clk_prepare_enable(csi2rx->pixel_clk[i]);
-		if (ret)
-			goto err_disable_pixclk;
-
-		reset_control_deassert(csi2rx->pixel_rst[i]);
-
 		writel(CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF |
 			       FIELD_PREP(CSI2RX_STREAM_CFG_NUM_PIXELS_MASK,
 					  csi2rx->num_pixels[i]),
@@ -415,30 +404,8 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 		       csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
 	}
 
-	ret = clk_prepare_enable(csi2rx->sys_clk);
-	if (ret)
-		goto err_disable_pixclk;
-
-	reset_control_deassert(csi2rx->sys_rst);
-
-	clk_disable_unprepare(csi2rx->p_clk);
 
 	return 0;
-
-err_disable_pixclk:
-	for (; i > 0; i--) {
-		reset_control_assert(csi2rx->pixel_rst[i - 1]);
-		clk_disable_unprepare(csi2rx->pixel_clk[i - 1]);
-	}
-
-	if (csi2rx->dphy) {
-		writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
-		phy_power_off(csi2rx->dphy);
-	}
-err_disable_pclk:
-	clk_disable_unprepare(csi2rx->p_clk);
-
-	return ret;
 }
 
 static void csi2rx_stop(struct csi2rx_priv *csi2rx)
@@ -447,10 +414,6 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
 	u32 val;
 	int ret;
 
-	clk_prepare_enable(csi2rx->p_clk);
-	reset_control_assert(csi2rx->sys_rst);
-	clk_disable_unprepare(csi2rx->sys_clk);
-
 	writel(0, csi2rx->base + CSI2RX_ERROR_IRQS_MASK_REG);
 
 	for (i = 0; i < csi2rx->max_streams; i++) {
@@ -465,14 +428,8 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
 		if (ret)
 			dev_warn(csi2rx->dev,
 				 "Failed to stop streaming on pad%u\n", i);
-
-		reset_control_assert(csi2rx->pixel_rst[i]);
-		clk_disable_unprepare(csi2rx->pixel_clk[i]);
 	}
 
-	reset_control_assert(csi2rx->p_rst);
-	clk_disable_unprepare(csi2rx->p_clk);
-
 	if (csi2rx->dphy) {
 		writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
 
@@ -548,10 +505,17 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
 	 * enable the whole controller.
 	 */
 	if (!csi2rx->count) {
+		ret = pm_runtime_resume_and_get(csi2rx->dev);
+		if (ret < 0)
+			return ret;
+
 		csi2rx_update_vc_select(csi2rx, state);
+
 		ret = csi2rx_start(csi2rx);
-		if (ret)
+		if (ret) {
+			pm_runtime_put(csi2rx->dev);
 			return ret;
+		}
 	}
 
 	/* Start streaming on the source */
@@ -561,8 +525,10 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
 		dev_err(csi2rx->dev,
 			"Failed to start streams %#llx on subdev\n",
 			sink_streams);
-		if (!csi2rx->count)
+		if (!csi2rx->count) {
 			csi2rx_stop(csi2rx);
+			pm_runtime_put(csi2rx->dev);
+		}
 		return ret;
 	}
 
@@ -589,8 +555,10 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
 	csi2rx->count--;
 
 	/* Let the last user turn off the lights. */
-	if (!csi2rx->count)
+	if (!csi2rx->count) {
 		csi2rx_stop(csi2rx);
+		pm_runtime_put(csi2rx->dev);
+	}
 
 	return 0;
 }
@@ -1092,6 +1060,7 @@ static int csi2rx_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_cleanup;
 
+	pm_runtime_enable(csi2rx->dev);
 	ret = v4l2_async_register_subdev(&csi2rx->subdev);
 	if (ret < 0)
 		goto err_free_state;
@@ -1106,6 +1075,7 @@ static int csi2rx_probe(struct platform_device *pdev)
 
 err_free_state:
 	v4l2_subdev_cleanup(&csi2rx->subdev);
+	pm_runtime_disable(csi2rx->dev);
 err_cleanup:
 	v4l2_async_nf_unregister(&csi2rx->notifier);
 	v4l2_async_nf_cleanup(&csi2rx->notifier);
@@ -1124,9 +1094,73 @@ static void csi2rx_remove(struct platform_device *pdev)
 	v4l2_async_unregister_subdev(&csi2rx->subdev);
 	v4l2_subdev_cleanup(&csi2rx->subdev);
 	media_entity_cleanup(&csi2rx->subdev.entity);
+	pm_runtime_disable(csi2rx->dev);
 	kfree(csi2rx);
 }
 
+static int csi2rx_runtime_suspend(struct device *dev)
+{
+	struct csi2rx_priv *csi2rx = dev_get_drvdata(dev);
+	unsigned int i;
+
+	reset_control_assert(csi2rx->sys_rst);
+	clk_disable_unprepare(csi2rx->sys_clk);
+
+	for (i = 0; i < csi2rx->max_streams; i++) {
+		reset_control_assert(csi2rx->pixel_rst[i]);
+		clk_disable_unprepare(csi2rx->pixel_clk[i]);
+	}
+
+	reset_control_assert(csi2rx->p_rst);
+	clk_disable_unprepare(csi2rx->p_clk);
+
+	return 0;
+}
+
+static int csi2rx_runtime_resume(struct device *dev)
+{
+	struct csi2rx_priv *csi2rx = dev_get_drvdata(dev);
+	unsigned int i;
+	int ret;
+
+	ret = clk_prepare_enable(csi2rx->p_clk);
+	if (ret)
+		return ret;
+
+	reset_control_deassert(csi2rx->p_rst);
+
+	for (i = 0; i < csi2rx->max_streams; i++) {
+		ret = clk_prepare_enable(csi2rx->pixel_clk[i]);
+		if (ret)
+			goto err_disable_pixclk;
+
+		reset_control_deassert(csi2rx->pixel_rst[i]);
+	}
+
+	ret = clk_prepare_enable(csi2rx->sys_clk);
+	if (ret)
+		goto err_disable_pixclk;
+
+	reset_control_deassert(csi2rx->sys_rst);
+
+	return 0;
+
+err_disable_pixclk:
+	for (; i > 0; i--) {
+		reset_control_assert(csi2rx->pixel_rst[i - 1]);
+		clk_disable_unprepare(csi2rx->pixel_clk[i - 1]);
+	}
+
+	reset_control_assert(csi2rx->p_rst);
+	clk_disable_unprepare(csi2rx->p_clk);
+
+	return ret;
+}
+
+static const struct dev_pm_ops csi2rx_pm_ops = {
+	RUNTIME_PM_OPS(csi2rx_runtime_suspend, csi2rx_runtime_resume, NULL)
+};
+
 static const struct of_device_id csi2rx_of_table[] = {
 	{ .compatible = "starfive,jh7110-csi2rx" },
 	{ .compatible = "cdns,csi2rx" },
@@ -1141,6 +1175,7 @@ static struct platform_driver csi2rx_driver = {
 	.driver	= {
 		.name		= "cdns-csi2rx",
 		.of_match_table	= csi2rx_of_table,
+		.pm		= &csi2rx_pm_ops,
 	},
 };
 module_platform_driver(csi2rx_driver);
-- 
2.34.1

[PATCH v8 17/18] media: ti: j721e-csi2rx: Support runtime suspend

[Rishikesh Donadkar]

From: Jai Luthra <jai.luthra@ideasonboard.com>

Add support for runtime power-management to enable powering off the
shared power domain between Cadence CSI2RX and TI CSI2RX wrapper when
the device(s) are not in use.

When powering off the IP, the PSI-L endpoint loses the paired DMA
channels. Thus we have to release the DMA channels at runtime suspend
and request them again at resume.

Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 drivers/media/platform/ti/Kconfig             |  1 +
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 55 ++++++++++++++++++-
 2 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
index 3bc4aa35887e6..a808063e24779 100644
--- a/drivers/media/platform/ti/Kconfig
+++ b/drivers/media/platform/ti/Kconfig
@@ -70,6 +70,7 @@ config VIDEO_TI_J721E_CSI2RX
 	depends on VIDEO_CADENCE_CSI2RX
 	depends on PHY_CADENCE_DPHY_RX || COMPILE_TEST
 	depends on ARCH_K3 || COMPILE_TEST
+	depends on PM
 	select VIDEOBUF2_DMA_CONTIG
 	select V4L2_FWNODE
 	help
diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 528041ee78cf3..21e032c64b901 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/property.h>
 
 #include <media/cadence/cdns-csi2rx.h>
@@ -963,12 +964,16 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	unsigned long flags;
 	int ret = 0;
 
+	ret = pm_runtime_resume_and_get(csi->dev);
+	if (ret)
+		return ret;
+
 	spin_lock_irqsave(&dma->lock, flags);
 	if (list_empty(&dma->queue))
 		ret = -EIO;
 	spin_unlock_irqrestore(&dma->lock, flags);
 	if (ret)
-		return ret;
+		goto err;
 
 	ret = video_device_pipeline_start(&ctx->vdev, &csi->pipe);
 	if (ret)
@@ -1024,6 +1029,8 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
 err:
 	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
+	pm_runtime_put(csi->dev);
+
 	return ret;
 }
 
@@ -1055,6 +1062,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 
 	ti_csi2rx_stop_dma(ctx);
 	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
+	pm_runtime_put(csi->dev);
 }
 
 static const struct vb2_ops csi_vb2_qops = {
@@ -1261,7 +1269,9 @@ static void ti_csi2rx_cleanup_notifier(struct ti_csi2rx_dev *csi)
 
 static void ti_csi2rx_cleanup_ctx(struct ti_csi2rx_ctx *ctx)
 {
-	dma_release_channel(ctx->dma.chan);
+	if (!pm_runtime_status_suspended(ctx->csi->dev))
+		dma_release_channel(ctx->dma.chan);
+
 	vb2_queue_release(&ctx->vidq);
 
 	video_unregister_device(&ctx->vdev);
@@ -1512,6 +1522,39 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
 	return ret;
 }
 
+static int ti_csi2rx_runtime_suspend(struct device *dev)
+{
+	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
+	int i;
+
+	if (csi->enable_count != 0)
+		return -EBUSY;
+
+	for (i = 0; i < csi->num_ctx; i++)
+		dma_release_channel(csi->ctx[i].dma.chan);
+
+	return 0;
+}
+
+static int ti_csi2rx_runtime_resume(struct device *dev)
+{
+	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
+	int ret, i;
+
+	for (i = 0; i < csi->num_ctx; i++) {
+		ret = ti_csi2rx_init_dma(&csi->ctx[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops ti_csi2rx_pm_ops = {
+	RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
+		       NULL)
+};
+
 static int ti_csi2rx_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -1579,6 +1622,10 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 		goto err_notifier;
 	}
 
+	pm_runtime_set_active(csi->dev);
+	pm_runtime_enable(csi->dev);
+	pm_request_idle(csi->dev);
+
 	return 0;
 
 err_notifier:
@@ -1609,6 +1656,9 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
 	mutex_destroy(&csi->mutex);
 	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
 			  csi->drain.paddr);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+
 }
 
 static const struct of_device_id ti_csi2rx_of_match[] = {
@@ -1623,6 +1673,7 @@ static struct platform_driver ti_csi2rx_pdrv = {
 	.driver = {
 		.name = TI_CSI2RX_MODULE_NAME,
 		.of_match_table = ti_csi2rx_of_match,
+		.pm		= &ti_csi2rx_pm_ops,
 	},
 };
 
-- 
2.34.1

[PATCH v8 18/18] media: ti: j721e-csi2rx: Support system suspend using pm_notifier

[Rishikesh Donadkar]

From: Jai Luthra <jai.luthra@ideasonboard.com>

As this device is the "orchestrator" for the rest of the media
pipeline, we need to stop all on-going streams before system suspend and
enable them back when the system wakes up from sleep.

Using .suspend/.resume callbacks does not work, as the order of those
callbacks amongst various devices in the camera pipeline like the sensor,
FPD serdes, CSI bridge etc. is impossible to enforce, even with
device links. For example, the Cadence CSI bridge is a child device of
this device, thus we cannot create a device link with the CSI bridge as
a provider and this device as consumer. This can lead to situations
where all the dependencies for the bridge have not yet resumed when we
request the subdev to start streaming again through the .resume callback
defined in this device.

Instead here we register a notifier callback with the PM framework
which is triggered when the system is fully functional. At this point we
can cleanly stop or start the streams, because we know all other devices
and their dependencies are functional. A downside of this approach is
that the userspace is also alive (not frozen yet, or just thawed), so
the suspend notifier might complete before the userspace has completed
all ioctls, like QBUF/DQBUF/STREAMON/STREAMOFF.

Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
---
 .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 128 ++++++++++++++++++
 1 file changed, 128 insertions(+)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 21e032c64b901..dd47758d51a90 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -131,6 +131,7 @@ struct ti_csi2rx_dev {
 	struct v4l2_subdev		*source;
 	struct v4l2_subdev		subdev;
 	struct ti_csi2rx_ctx		ctx[TI_CSI2RX_MAX_CTX];
+	struct notifier_block		pm_notifier;
 	u8				pix_per_clk;
 	/* Buffer to drain stale data from PSI-L endpoint */
 	struct {
@@ -1550,6 +1551,124 @@ static int ti_csi2rx_runtime_resume(struct device *dev)
 	return 0;
 }
 
+static int ti_csi2rx_suspend(struct device *dev)
+{
+	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
+	enum ti_csi2rx_dma_state state;
+	struct ti_csi2rx_ctx *ctx;
+	struct ti_csi2rx_dma *dma;
+	unsigned long flags = 0;
+	int i, ret = 0;
+
+	/* If device was not in use we can simply suspend */
+	if (pm_runtime_status_suspended(dev))
+		return 0;
+
+	/*
+	 * If device is running, assert the pixel reset to cleanly stop any
+	 * on-going streams before we suspend.
+	 */
+	writel(0, csi->shim + SHIM_CNTL);
+
+	for (i = 0; i < csi->num_ctx; i++) {
+		ctx = &csi->ctx[i];
+		dma = &ctx->dma;
+
+		spin_lock_irqsave(&dma->lock, flags);
+		state = dma->state;
+		spin_unlock_irqrestore(&dma->lock, flags);
+
+		if (state != TI_CSI2RX_DMA_STOPPED) {
+			/* Disable source */
+			ret = v4l2_subdev_disable_streams(&csi->subdev,
+							  TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
+							  BIT(0));
+			if (ret)
+				dev_err(csi->dev, "Failed to stop subdev stream\n");
+		}
+
+		/* Stop any on-going streams */
+		writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
+
+		/* Drain DMA */
+		ti_csi2rx_drain_dma(ctx);
+
+		/* Terminate DMA */
+		ret = dmaengine_terminate_sync(ctx->dma.chan);
+		if (ret)
+			dev_err(csi->dev, "Failed to stop DMA\n");
+	}
+
+	return ret;
+}
+
+static int ti_csi2rx_resume(struct device *dev)
+{
+	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
+	struct ti_csi2rx_ctx *ctx;
+	struct ti_csi2rx_dma *dma;
+	struct ti_csi2rx_buffer *buf;
+	unsigned long flags = 0;
+	unsigned int reg;
+	int i, ret = 0;
+
+	/* If device was not in use, we can simply wakeup */
+	if (pm_runtime_status_suspended(dev))
+		return 0;
+
+	/* If device was in use before, restore all the running streams */
+	reg = SHIM_CNTL_PIX_RST;
+	writel(reg, csi->shim + SHIM_CNTL);
+
+	for (i = 0; i < csi->num_ctx; i++) {
+		ctx = &csi->ctx[i];
+		dma = &ctx->dma;
+		spin_lock_irqsave(&dma->lock, flags);
+		if (dma->state != TI_CSI2RX_DMA_STOPPED) {
+			/* Re-submit all previously submitted buffers to DMA */
+			list_for_each_entry(buf, &ctx->dma.submitted, list) {
+				ti_csi2rx_start_dma(ctx, buf);
+			}
+			spin_unlock_irqrestore(&dma->lock, flags);
+
+			/* Restore stream config */
+			ti_csi2rx_setup_shim(ctx);
+
+			ret = v4l2_subdev_enable_streams(&csi->subdev,
+							 TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
+							 BIT(0));
+			if (ret)
+				dev_err(ctx->csi->dev, "Failed to start subdev\n");
+		} else {
+			spin_unlock_irqrestore(&dma->lock, flags);
+		}
+	}
+
+	return ret;
+}
+
+static int ti_csi2rx_pm_notifier(struct notifier_block *nb,
+				 unsigned long action, void *data)
+{
+	struct ti_csi2rx_dev *csi =
+		container_of(nb, struct ti_csi2rx_dev, pm_notifier);
+
+	switch (action) {
+	case PM_HIBERNATION_PREPARE:
+	case PM_SUSPEND_PREPARE:
+	case PM_RESTORE_PREPARE:
+		ti_csi2rx_suspend(csi->dev);
+		break;
+	case PM_POST_SUSPEND:
+	case PM_POST_HIBERNATION:
+	case PM_POST_RESTORE:
+		ti_csi2rx_resume(csi->dev);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
 static const struct dev_pm_ops ti_csi2rx_pm_ops = {
 	RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
 		       NULL)
@@ -1622,6 +1741,13 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 		goto err_notifier;
 	}
 
+	csi->pm_notifier.notifier_call = ti_csi2rx_pm_notifier;
+	ret = register_pm_notifier(&csi->pm_notifier);
+	if (ret) {
+		dev_err(csi->dev, "Failed to create PM notifier: %d\n", ret);
+		goto err_notifier;
+	}
+
 	pm_runtime_set_active(csi->dev);
 	pm_runtime_enable(csi->dev);
 	pm_request_idle(csi->dev);
@@ -1652,6 +1778,8 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
 		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
 
 	ti_csi2rx_cleanup_notifier(csi);
+	unregister_pm_notifier(&csi->pm_notifier);
+
 	ti_csi2rx_cleanup_v4l2(csi);
 	mutex_destroy(&csi->mutex);
 	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
-- 
2.34.1

Re: [PATCH v8 01/18] media: ti: j721e-csi2rx: Remove word size alignment on frame width

[Tomi Valkeinen]

Hi,

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> j721e-csi2rx driver has a limitation of frame width being a multiple
> word size. However, there is no such limitation imposed by the
> hardware [1].
> 
> Remove this limitation from the driver.
> 
> Link: https://www.ti.com/lit/pdf/spruj16
> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 24 ++++---------------
>  1 file changed, 4 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> index b75aa363d1bf2..710d05a053539 100644
> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> @@ -43,7 +43,6 @@
>  #define SHIM_PSI_CFG0_DST_TAG		GENMASK(31, 16)
>  
>  #define TI_CSI2RX_MAX_PIX_PER_CLK	4
> -#define PSIL_WORD_SIZE_BYTES		16
>  /*
>   * There are no hard limits on the width or height. The DMA engine can handle
>   * all sizes. The max width and height are arbitrary numbers for this driver.
> @@ -250,19 +249,12 @@ static void ti_csi2rx_fill_fmt(const struct ti_csi2rx_fmt *csi_fmt,
>  			       struct v4l2_format *v4l2_fmt)
>  {
>  	struct v4l2_pix_format *pix = &v4l2_fmt->fmt.pix;
> -	unsigned int pixels_in_word;
> -
> -	pixels_in_word = PSIL_WORD_SIZE_BYTES * 8 / csi_fmt->bpp;
>  
>  	/* Clamp width and height to sensible maximums (16K x 16K) */
>  	pix->width = clamp_t(unsigned int, pix->width,
> -			     pixels_in_word,
> -			     MAX_WIDTH_BYTES * 8 / csi_fmt->bpp);
> +			     1, MAX_WIDTH_BYTES * 8 / csi_fmt->bpp);
>  	pix->height = clamp_t(unsigned int, pix->height, 1, MAX_HEIGHT_LINES);
>  
> -	/* Width should be a multiple of transfer word-size */
> -	pix->width = rounddown(pix->width, pixels_in_word);
> -
>  	v4l2_fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
>  	pix->pixelformat = csi_fmt->fourcc;
>  	pix->bytesperline = pix->width * (csi_fmt->bpp / 8);
> @@ -360,23 +352,15 @@ static int ti_csi2rx_enum_framesizes(struct file *file, void *fh,
>  				     struct v4l2_frmsizeenum *fsize)
>  {
>  	const struct ti_csi2rx_fmt *fmt;
> -	unsigned int pixels_in_word;
>  
>  	fmt = find_format_by_fourcc(fsize->pixel_format);
>  	if (!fmt || fsize->index != 0)
>  		return -EINVAL;
>  
> -	/*
> -	 * Number of pixels in one PSI-L word. The transfer happens in multiples
> -	 * of PSI-L word sizes.
> -	 */
> -	pixels_in_word = PSIL_WORD_SIZE_BYTES * 8 / fmt->bpp;
> -
>  	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
> -	fsize->stepwise.min_width = pixels_in_word;
> -	fsize->stepwise.max_width = rounddown(MAX_WIDTH_BYTES * 8 / fmt->bpp,
> -					      pixels_in_word);
> -	fsize->stepwise.step_width = pixels_in_word;
> +	fsize->stepwise.min_width = 1;
> +	fsize->stepwise.max_width = MAX_WIDTH_BYTES * 8 / fmt->bpp;
> +	fsize->stepwise.step_width = 1;
>  	fsize->stepwise.min_height = 1;
>  	fsize->stepwise.max_height = MAX_HEIGHT_LINES;
>  	fsize->stepwise.step_height = 1;

Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

 Tomi

Re: [PATCH v8 11/18] media: ti: j721e-csi2rx: add support for processing virtual channels

[Tomi Valkeinen]

Hi,

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> From: Jai Luthra <j-luthra@ti.com>
> 
> Use get_frame_desc() to get the frame desc from the connected source,
> and use the provided virtual channel instead of hardcoded one.

So this baffled me a bit: the code seems to get the VC from the frame
desc, but not the DT. But it looks like the DT values are hardcoded in
the driver's formats table, and those are used for DT filtering.

We need to do something like that for legacy cases where the source does
not support get_frame_desc, but if there is a frame desc, we should use
the DT and VC from the frame desc.

> get_frame_desc() returns the same information when called on each stream
> start, so instead get the VCs for all the routed stream at first
> stream start and cache this information in the driver.

I get the point but... There isn't anything like this in the patch?

> get_frame_desc() works per stream, but as we don't support multiple

"get_frame_desc() works per stream", what does it mean? It returns all
the streams for a pad.

> streams yet, we will just always use stream 0. If the source doesn't
> support get_frame_desc(), fall back to the previous method of always
> capturing virtual channel 0.

Right, if there's no frame desc (and we need to support legacy drivers),
the driver should default to VC=0, DT from the formats table. But as
mentioned above, VC and DT should normally come from the frame desc. It
would be good to have a separate "legacy" function/branch/something, so
that we clearly distinguish the legacy and frame-desc cases.

 Tomi

> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
> Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 38 +++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> index 5c4524bf42e6e..126a62fa2c4c4 100644
> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> @@ -32,6 +32,7 @@
>  #define SHIM_DMACNTX_YUV422		GENMASK(27, 26)
>  #define SHIM_DMACNTX_DUAL_PCK_CFG	BIT(24)
>  #define SHIM_DMACNTX_SIZE		GENMASK(21, 20)
> +#define SHIM_DMACNTX_VC			GENMASK(9, 6)
>  #define SHIM_DMACNTX_FMT		GENMASK(5, 0)
>  #define SHIM_DMACNTX_YUV422_MODE_11	3
>  #define SHIM_DMACNTX_SIZE_8		0
> @@ -110,6 +111,8 @@ struct ti_csi2rx_ctx {
>  	struct media_pad		pad;
>  	u32				sequence;
>  	u32				idx;
> +	u32				vc;
> +	u32				stream;
>  };
>  
>  struct ti_csi2rx_dev {
> @@ -610,6 +613,7 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
>  	}
>  
>  	reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
> +	reg |= FIELD_PREP(SHIM_DMACNTX_VC, ctx->vc);
>  
>  	writel(reg, csi->shim + SHIM_DMACNTX(ctx->idx));
>  
> @@ -884,6 +888,32 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
>  	}
>  }
>  
> +static int ti_csi2rx_get_vc(struct ti_csi2rx_ctx *ctx)
> +{
> +	struct ti_csi2rx_dev *csi = ctx->csi;
> +	struct v4l2_mbus_frame_desc fd;
> +	struct media_pad *pad;
> +	int ret, i;
> +
> +	pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
> +	if (!pad)
> +		return -ENODEV;
> +
> +	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, pad->index, &fd);
> +	if (ret)
> +		return ret;
> +
> +	if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
> +		return -EINVAL;
> +
> +	for (i = 0; i < fd.num_entries; i++) {
> +		if (ctx->stream == fd.entry[i].stream)
> +			return fd.entry[i].bus.csi2.vc;
> +	}
> +
> +	return -ENODEV;
> +}
> +
>  static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>  {
>  	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
> @@ -904,6 +934,14 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	if (ret)
>  		goto err;
>  
> +	ret = ti_csi2rx_get_vc(ctx);
> +	if (ret == -ENOIOCTLCMD)
> +		ctx->vc = 0;
> +	else if (ret < 0)
> +		goto err;
> +	else
> +		ctx->vc = ret;
> +
>  	ti_csi2rx_setup_shim(ctx);
>  
>  	ctx->sequence = 0;

Re: [PATCH v8 06/18] media: ti: j721e-csi2rx: add a subdev for the core device

[Sakari Ailus]

Hi Rishikesh,

On Wed, Nov 12, 2025 at 05:24:47PM +0530, Rishikesh Donadkar wrote:
> +static int ti_csi2rx_sd_s_stream(struct v4l2_subdev *sd, int enable)

Could you instead implement enable_streams and disable_streams pad ops,
please, and use v4l2_subdev_enable_streams() from there?

> +{
> +	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
> +	int ret = 0;
> +
> +	mutex_lock(&csi->mutex);
> +
> +	if (enable) {
> +		if (csi->enable_count > 0) {
> +			csi->enable_count++;
> +			goto out;
> +		}
> +
> +		ret = v4l2_subdev_call(csi->source, video, s_stream, 1);
> +		if (ret)
> +			goto out;
> +
> +		csi->enable_count++;
> +	} else {
> +		if (csi->enable_count == 0) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		if (--csi->enable_count > 0)
> +			goto out;
> +
> +		ret = v4l2_subdev_call(csi->source, video, s_stream, 0);
> +	}
> +
> +out:
> +	mutex_unlock(&csi->mutex);
> +	return ret;
> +}

-- 
Regards,

Sakari Ailus

Re: [PATCH v8 08/18] media: ti: j721e-csi2rx: Move to .enable/disable_streams API

[Sakari Ailus]

On Wed, Nov 12, 2025 at 05:24:49PM +0530, Rishikesh Donadkar wrote:
> Support the new enable_stream()/disable_stream() APIs in the subdev
> instead of s_stream() hook.
> 
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>

This addresses my comment on the 6th patch.

Shouldn't this be merged to that?

-- 
Sakari Ailus

Re: [PATCH v8 10/18] media: cadence: csi2rx: add get_frame_desc wrapper

[Tomi Valkeinen]

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> From: Pratyush Yadav <p.yadav@ti.com>
> 
> J721E wrapper CSI2RX driver needs to get the frame descriptor from the
> source to find out info about virtual channel. This driver itself does
> not touch the routing or virtual channels in any way. So simply pass the
> descriptor through from the source.

Unfortunately I think that doesn't work.

E.g. we have a fpdllink deser and the cdns csi2rx.

Deser's routing table (pad/stream):

0/0 -> 4/15
0/1 -> 4/33

So we have two streams coming into the deser's pad 0, with stream IDs 0
and 1. They are routed by the user to output pad 4, with stream IDs 15
and 33.

cdns csi2rx routing table:

0/15 -> 1/0
0/33 -> 1/1

So cdns csi2rx routes the streams through, as stream IDs 0 and 1 on the
output side.

With this patch, if the j2 csi2rx asks frame desc from cdns csi2rx, it
gets a frame desc with two streams, stream IDs 15 and 33.

I made this series for the issue above, but it hasn't been merged:

https://lore.kernel.org/all/20250324-frame-desc-passthrough-v4-0-dbe2412297cc%40ideasonboard.com/

 Tomi

> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  drivers/media/platform/cadence/cdns-csi2rx.c | 24 ++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 34da81893308b..3688077fa8347 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -229,6 +229,21 @@ static const struct csi2rx_fmt *csi2rx_get_fmt_by_code(u32 code)
>  	return NULL;
>  }
>  
> +static int csi2rx_get_frame_desc_from_source(struct csi2rx_priv *csi2rx,
> +					     struct v4l2_mbus_frame_desc *fd)
> +{
> +	struct media_pad *remote_pad;
> +
> +	remote_pad = media_entity_remote_source_pad_unique(&csi2rx->subdev.entity);
> +	if (!remote_pad) {
> +		dev_err(csi2rx->dev, "No remote pad found for sink\n");
> +		return -ENODEV;
> +	}
> +
> +	return v4l2_subdev_call(csi2rx->source_subdev, pad, get_frame_desc,
> +				remote_pad->index, fd);
> +}
> +
>  static inline
>  struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)
>  {
> @@ -611,12 +626,21 @@ int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
>  }
>  EXPORT_SYMBOL_FOR_MODULES(cdns_csi2rx_negotiate_ppc, "j721e-csi2rx");
>  
> +static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
> +				 struct v4l2_mbus_frame_desc *fd)
> +{
> +	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +
> +	return csi2rx_get_frame_desc_from_source(csi2rx, fd);
> +}
> +
>  static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
>  	.enum_mbus_code	= csi2rx_enum_mbus_code,
>  	.get_fmt	= v4l2_subdev_get_fmt,
>  	.set_fmt	= csi2rx_set_fmt,
>  	.enable_streams         = csi2rx_enable_streams,
>  	.disable_streams        = csi2rx_disable_streams,
> +	.get_frame_desc	= csi2rx_get_frame_desc,
>  };
>  
>  static const struct v4l2_subdev_core_ops csi2rx_core_ops = {

Re: [PATCH v8 12/18] media: cadence: csi2rx: add multistream support

[Sakari Ailus]

Hi Rishikesh,

I'm not commenting on the use of {en,dis}able_streams in the series; it may
be this area will need some work in general, including in V4L2 core.

On Wed, Nov 12, 2025 at 05:24:53PM +0530, Rishikesh Donadkar wrote:
> From: Jai Luthra <j-luthra@ti.com>
> 
> Cadence CSI-2 bridge IP supports capturing multiple virtual "streams"
> of data over the same physical interface using MIPI Virtual Channels.
> 
> While the hardware IP supports usecases where streams coming in the sink
> pad can be broadcasted to multiple source pads, the driver will need
> significant re-architecture to make that possible. The two users of this
> IP in mainline linux are TI Shim and StarFive JH7110 CAMSS, and both
> have only integrated the first source pad i.e stream0 of this IP. So for
> now keep it simple and only allow 1-to-1 mapping of streams from sink to
> source, without any broadcasting.
> 
> Implement a fallback s_stream hook that internally calls enable_stream
> on each source pad, for consumer drivers that don't use multi-stream
> APIs to still work. The helper function v4l2_subdev_s_stream_helper()
> form the v4l2 framework is not used here as it is meant only for the
> subedvs that have a single source pad and this hardware IP supports
> having multiple source pads.
> 
> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
> Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  drivers/media/platform/cadence/cdns-csi2rx.c | 283 ++++++++++++++++---
>  1 file changed, 236 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 3688077fa8347..833bc134f17cb 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -135,6 +135,7 @@ struct csi2rx_priv {
>  	struct phy			*dphy;
>  
>  	u8				num_pixels[CSI2RX_STREAMS_MAX];
> +	u32				vc_select[CSI2RX_STREAMS_MAX];
>  	u8				lanes[CSI2RX_LANES_MAX];
>  	u8				num_lanes;
>  	u8				max_lanes;
> @@ -273,30 +274,43 @@ static void csi2rx_reset(struct csi2rx_priv *csi2rx)
>  
>  static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
>  {
> -	struct media_pad *src_pad =
> -		&csi2rx->source_subdev->entity.pads[csi2rx->source_pad];
>  	union phy_configure_opts opts = { };
>  	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
> -	struct v4l2_subdev_state *state;
>  	struct v4l2_mbus_framefmt *framefmt;
> +	struct v4l2_subdev_state *state;
>  	const struct csi2rx_fmt *fmt;
> +	int source_pad = csi2rx->source_pad;
> +	struct media_pad *pad = &csi2rx->source_subdev->entity.pads[source_pad];
>  	s64 link_freq;
>  	int ret;
> +	u32 bpp;
>  
>  	state = v4l2_subdev_get_locked_active_state(&csi2rx->subdev);
>  
> -	framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
> -	if (!framefmt) {
> -		dev_err(csi2rx->dev, "Did not find active sink format\n");
> -		return -EINVAL;
> -	}
> +	/*
> +	 * For multi-stream transmitters there is no single pixel rate.
> +	 *
> +	 * In multistream usecase pass bpp as 0 so that v4l2_get_link_freq()
> +	 * returns an error if it falls back to V4L2_CID_PIXEL_RATE.
> +	 */
> +	if (state->routing.num_routes > 1) {
> +		bpp = 0;
> +	} else {
> +		framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
> +		if (!framefmt) {
> +			dev_err(csi2rx->dev, "Did not find active sink format\n");
> +			return -EINVAL;
> +		}
>  
> -	fmt = csi2rx_get_fmt_by_code(framefmt->code);
> +		fmt = csi2rx_get_fmt_by_code(framefmt->code);
> +		bpp = fmt->bpp;
> +	}
>  
> -	link_freq = v4l2_get_link_freq(src_pad,
> -				       fmt->bpp, 2 * csi2rx->num_lanes);
> -	if (link_freq < 0)
> +	link_freq = v4l2_get_link_freq(pad, bpp, 2 * csi2rx->num_lanes);
> +	if (link_freq < 0) {
> +		dev_err(csi2rx->dev, "Unable to calculate link frequency\n");
>  		return link_freq;
> +	}
>  
>  	ret = phy_mipi_dphy_get_default_config_for_hsclk(link_freq,
>  							 csi2rx->num_lanes, cfg);
> @@ -394,11 +408,7 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  					  csi2rx->num_pixels[i]),
>  		       csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
>  
> -		/*
> -		 * Enable one virtual channel. When multiple virtual channels
> -		 * are supported this will have to be changed.
> -		 */
> -		writel(CSI2RX_STREAM_DATA_CFG_VC_SELECT(0),
> +		writel(csi2rx->vc_select[i],
>  		       csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));
>  
>  		writel(CSI2RX_STREAM_CTRL_START,
> @@ -486,18 +496,59 @@ static int csi2rx_log_status(struct v4l2_subdev *sd)
>  	return 0;
>  }
>  
> +static void csi2rx_update_vc_select(struct csi2rx_priv *csi2rx,
> +				    struct v4l2_subdev_state *state)
> +{
> +	struct v4l2_mbus_frame_desc fd = {0};
> +	struct v4l2_subdev_route *route;
> +	unsigned int i;
> +	int ret;
> +
> +	/* Capture VC=0 by default */
> +	for (i = 0; i < CSI2RX_STREAMS_MAX; i++)
> +		csi2rx->vc_select[i] = CSI2RX_STREAM_DATA_CFG_VC_SELECT(0);
> +
> +	ret = csi2rx_get_frame_desc_from_source(csi2rx, &fd);
> +	if (ret || fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
> +		dev_dbg(csi2rx->dev,
> +			"Failed to get source frame desc, allowing only VC=0\n");
> +		return;
> +	}
> +
> +	/* If source provides per-stream VC info, use it to filter by VC */
> +	memset(csi2rx->vc_select, 0, sizeof(csi2rx->vc_select));
> +
> +	for_each_active_route(&state->routing, route) {
> +		u32 cdns_stream = route->source_pad - CSI2RX_PAD_SOURCE_STREAM0;
> +
> +		for (i = 0; i < fd.num_entries; i++) {
> +			if (fd.entry[i].stream != route->sink_stream)
> +				continue;
> +
> +			csi2rx->vc_select[cdns_stream] |=
> +				CSI2RX_STREAM_DATA_CFG_VC_SELECT(fd.entry[i].bus.csi2.vc);
> +		}
> +	}
> +}
> +
>  static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>  				 struct v4l2_subdev_state *state, u32 pad,
>  				 u64 streams_mask)
>  {
>  	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +	u64 sink_streams;
>  	int ret;
>  
> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
> +						       CSI2RX_PAD_SINK,
> +						       &streams_mask);
> +
>  	/*
>  	 * If we're not the first users, there's no need to
>  	 * enable the whole controller.
>  	 */
>  	if (!csi2rx->count) {
> +		csi2rx_update_vc_select(csi2rx, state);
>  		ret = csi2rx_start(csi2rx);
>  		if (ret)
>  			return ret;
> @@ -505,10 +556,11 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>  
>  	/* Start streaming on the source */
>  	ret = v4l2_subdev_enable_streams(csi2rx->source_subdev, csi2rx->source_pad,
> -					 BIT(0));
> +					 sink_streams);
>  	if (ret) {
>  		dev_err(csi2rx->dev,
> -			"Failed to start streams %d on subdev\n", 0);
> +			"Failed to start streams %#llx on subdev\n",
> +			sink_streams);
>  		if (!csi2rx->count)
>  			csi2rx_stop(csi2rx);
>  		return ret;
> @@ -523,9 +575,14 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>  				  u64 streams_mask)
>  {
>  	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +	u64 sink_streams;
> +
> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
> +						       CSI2RX_PAD_SINK,
> +						       &streams_mask);
>  
>  	if (v4l2_subdev_disable_streams(csi2rx->source_subdev,
> -					csi2rx->source_pad, BIT(0))) {
> +						 csi2rx->source_pad, sink_streams)) {
>  		dev_err(csi2rx->dev, "Couldn't disable our subdev\n");
>  	}
>  
> @@ -538,6 +595,36 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>  	return 0;
>  }
>  
> +static int csi2rx_s_stream_fallback(struct v4l2_subdev *sd, int enable)

What do you need this for? I presume you'd have a sub-device driver
downstream calling this, but wouldn't you always use {en,dis}able_streams
from that driver?

> +{
> +	struct v4l2_subdev_state *state;
> +	struct v4l2_subdev_route *route;
> +	u64 mask[CSI2RX_PAD_MAX] = {0};
> +	int i, ret;
> +
> +	/* Find the stream mask on all source pads */
> +	state = v4l2_subdev_lock_and_get_active_state(sd);
> +	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
> +		for_each_active_route(&state->routing, route) {
> +			if (route->source_pad == i)
> +				mask[i] |= BIT_ULL(route->source_stream);
> +		}
> +	}
> +	v4l2_subdev_unlock_state(state);
> +
> +	/* Start streaming on each pad */
> +	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
> +		if (enable)
> +			ret = v4l2_subdev_enable_streams(sd, i, mask[i]);
> +		else
> +			ret = v4l2_subdev_disable_streams(sd, i, mask[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return ret;
> +}
> +
>  static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>  				 struct v4l2_subdev_state *state,
>  				 struct v4l2_subdev_mbus_code_enum *code_enum)
> @@ -550,12 +637,56 @@ static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>  	return 0;
>  }
>  
> +static int _csi2rx_set_routing(struct v4l2_subdev *subdev,
> +			       struct v4l2_subdev_state *state,
> +			       struct v4l2_subdev_krouting *routing)
> +{
> +	static const struct v4l2_mbus_framefmt format = {
> +		.width = 640,
> +		.height = 480,
> +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> +		.field = V4L2_FIELD_NONE,
> +		.colorspace = V4L2_COLORSPACE_SRGB,
> +		.ycbcr_enc = V4L2_YCBCR_ENC_601,
> +		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
> +		.xfer_func = V4L2_XFER_FUNC_SRGB,
> +	};
> +	int ret;
> +
> +	if (routing->num_routes > V4L2_FRAME_DESC_ENTRY_MAX)
> +		return -EINVAL;
> +
> +	ret = v4l2_subdev_routing_validate(subdev, routing,
> +					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
> +	if (ret)
> +		return ret;
> +
> +	return v4l2_subdev_set_routing_with_fmt(subdev, state, routing, &format);
> +}
> +
> +static int csi2rx_set_routing(struct v4l2_subdev *subdev,
> +			      struct v4l2_subdev_state *state,
> +			      enum v4l2_subdev_format_whence which,
> +			      struct v4l2_subdev_krouting *routing)
> +{
> +	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +	int ret;
> +
> +	if (which == V4L2_SUBDEV_FORMAT_ACTIVE && csi2rx->count)
> +		return -EBUSY;
> +
> +	ret = _csi2rx_set_routing(subdev, state, routing);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
>  static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>  			  struct v4l2_subdev_state *state,
>  			  struct v4l2_subdev_format *format)
>  {
>  	struct v4l2_mbus_framefmt *fmt;
> -	unsigned int i;
>  
>  	/* No transcoding, source and sink formats must match. */
>  	if (format->pad != CSI2RX_PAD_SINK)
> @@ -567,14 +698,16 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>  	format->format.field = V4L2_FIELD_NONE;
>  
>  	/* Set sink format */
> -	fmt = v4l2_subdev_state_get_format(state, format->pad);
> +	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
>  	*fmt = format->format;
>  
> -	/* Propagate to source formats */
> -	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
> -		fmt = v4l2_subdev_state_get_format(state, i);
> -		*fmt = format->format;
> -	}
> +	/* Propagate to source format */
> +	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
> +							   format->stream);
> +	if (!fmt)
> +		return -EINVAL;
> +
> +	*fmt = format->format;
>  
>  	return 0;
>  }
> @@ -582,21 +715,22 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>  static int csi2rx_init_state(struct v4l2_subdev *subdev,
>  			     struct v4l2_subdev_state *state)
>  {
> -	struct v4l2_subdev_format format = {
> -		.pad = CSI2RX_PAD_SINK,
> -		.format = {
> -			.width = 640,
> -			.height = 480,
> -			.code = MEDIA_BUS_FMT_UYVY8_1X16,
> -			.field = V4L2_FIELD_NONE,
> -			.colorspace = V4L2_COLORSPACE_SRGB,
> -			.ycbcr_enc = V4L2_YCBCR_ENC_601,
> -			.quantization = V4L2_QUANTIZATION_LIM_RANGE,
> -			.xfer_func = V4L2_XFER_FUNC_SRGB,
> +	struct v4l2_subdev_route routes[] = {
> +		{
> +			.sink_pad = CSI2RX_PAD_SINK,
> +			.sink_stream = 0,
> +			.source_pad = CSI2RX_PAD_SOURCE_STREAM0,
> +			.source_stream = 0,
> +			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
>  		},
>  	};
>  
> -	return csi2rx_set_fmt(subdev, state, &format);
> +	struct v4l2_subdev_krouting routing = {
> +		.num_routes = ARRAY_SIZE(routes),
> +		.routes = routes,
> +	};
> +
> +	return _csi2rx_set_routing(subdev, state, &routing);
>  }
>  
>  int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
> @@ -630,17 +764,70 @@ static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
>  				 struct v4l2_mbus_frame_desc *fd)
>  {
>  	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +	struct v4l2_mbus_frame_desc source_fd = {0};
> +	struct v4l2_subdev_route *route;
> +	struct v4l2_subdev_state *state;
> +	int ret;
> +
> +	ret = csi2rx_get_frame_desc_from_source(csi2rx, &source_fd);
> +	if (ret)
> +		return ret;
> +
> +	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
> +
> +	state = v4l2_subdev_lock_and_get_active_state(subdev);
> +
> +	for_each_active_route(&state->routing, route) {
> +		struct v4l2_mbus_frame_desc_entry *source_entry = NULL;
> +		unsigned int i;
> +
> +		if (route->source_pad != pad)
> +			continue;
> +
> +		for (i = 0; i < source_fd.num_entries; i++) {
> +			if (source_fd.entry[i].stream == route->sink_stream) {
> +				source_entry = &source_fd.entry[i];
> +				break;
> +			}
> +		}
> +
> +		if (!source_entry) {
> +			dev_err(csi2rx->dev,
> +				"Failed to find stream from source frame desc\n");
> +			ret = -EPIPE;
> +			goto err_missing_stream;
> +		}
> +
> +		fd->entry[fd->num_entries].stream = route->source_stream;
> +		fd->entry[fd->num_entries].flags = source_entry->flags;
> +		fd->entry[fd->num_entries].length = source_entry->length;
> +		fd->entry[fd->num_entries].pixelcode = source_entry->pixelcode;
> +		fd->entry[fd->num_entries].bus.csi2.vc =
> +			source_entry->bus.csi2.vc;
> +		fd->entry[fd->num_entries].bus.csi2.dt =
> +			source_entry->bus.csi2.dt;
> +
> +		fd->num_entries++;
> +	}
> +
> +err_missing_stream:
> +	v4l2_subdev_unlock_state(state);
>  
> -	return csi2rx_get_frame_desc_from_source(csi2rx, fd);
> +	return ret;
>  }
>  
>  static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
> -	.enum_mbus_code	= csi2rx_enum_mbus_code,
> -	.get_fmt	= v4l2_subdev_get_fmt,
> -	.set_fmt	= csi2rx_set_fmt,
> -	.enable_streams         = csi2rx_enable_streams,
> -	.disable_streams        = csi2rx_disable_streams,
> -	.get_frame_desc	= csi2rx_get_frame_desc,
> +	.enum_mbus_code		= csi2rx_enum_mbus_code,
> +	.get_fmt		= v4l2_subdev_get_fmt,
> +	.set_fmt		= csi2rx_set_fmt,
> +	.get_frame_desc		= csi2rx_get_frame_desc,
> +	.set_routing		= csi2rx_set_routing,
> +	.enable_streams		= csi2rx_enable_streams,
> +	.disable_streams	= csi2rx_disable_streams,
> +};
> +
> +static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
> +	.s_stream	= csi2rx_s_stream_fallback,
>  };
>  
>  static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
> @@ -649,6 +836,7 @@ static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>  
>  static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
>  	.core		= &csi2rx_core_ops,
> +	.video		= &csi2rx_video_ops,
>  	.pad		= &csi2rx_pad_ops,
>  };
>  
> @@ -876,7 +1064,8 @@ static int csi2rx_probe(struct platform_device *pdev)
>  	csi2rx->pads[CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>  	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
>  		csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
> -	csi2rx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	csi2rx->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE |
> +		V4L2_SUBDEV_FL_STREAMS;
>  	csi2rx->subdev.entity.ops = &csi2rx_media_ops;
>  
>  	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v8 07/18] media: cadence: csi2rx: Move to .enable/disable_streams API

[Tomi Valkeinen]

Hi,

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> The enable_streams() API in v4l2 supports passing a bitmask to enable
> each pad/stream combination individually on any media subdev. Use this
> API instead of  s_stream() API.
> 
> Implement the enable_stream and disable_stream hooks in place of the
> stream-unaware s_stream hook.
> 
> Remove the lock that was used to serialize stream starts/stops which
> is not required anymore since the v4l2-core serializes the
> enable/disable_streams() calls for the subdev.
> 
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  drivers/media/platform/cadence/cdns-csi2rx.c | 108 +++++++++----------
>  1 file changed, 54 insertions(+), 54 deletions(-)
> 
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 8c19f125da3e5..34da81893308b 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -125,12 +125,6 @@ struct csi2rx_priv {
>  	unsigned int			count;
>  	int				error_irq;
>  
> -	/*
> -	 * Used to prevent race conditions between multiple,
> -	 * concurrent calls to start and stop.
> -	 */
> -	struct mutex			lock;
> -
>  	void __iomem			*base;
>  	struct clk			*sys_clk;
>  	struct clk			*p_clk;
> @@ -268,20 +262,21 @@ static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
>  		&csi2rx->source_subdev->entity.pads[csi2rx->source_pad];
>  	union phy_configure_opts opts = { };
>  	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
> -	struct v4l2_subdev_format sd_fmt = {
> -		.which	= V4L2_SUBDEV_FORMAT_ACTIVE,
> -		.pad	= CSI2RX_PAD_SINK,
> -	};
> +	struct v4l2_subdev_state *state;
> +	struct v4l2_mbus_framefmt *framefmt;
>  	const struct csi2rx_fmt *fmt;
>  	s64 link_freq;
>  	int ret;
>  
> -	ret = v4l2_subdev_call_state_active(&csi2rx->subdev, pad, get_fmt,
> -					    &sd_fmt);
> -	if (ret < 0)
> -		return ret;
> +	state = v4l2_subdev_get_locked_active_state(&csi2rx->subdev);
>  
> -	fmt = csi2rx_get_fmt_by_code(sd_fmt.format.code);
> +	framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
> +	if (!framefmt) {
> +		dev_err(csi2rx->dev, "Did not find active sink format\n");
> +		return -EINVAL;
> +	}
> +
> +	fmt = csi2rx_get_fmt_by_code(framefmt->code);
>  
>  	link_freq = v4l2_get_link_freq(src_pad,
>  				       fmt->bpp, 2 * csi2rx->num_lanes);
> @@ -401,16 +396,10 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  
>  	reset_control_deassert(csi2rx->sys_rst);
>  
> -	ret = v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, true);
> -	if (ret)
> -		goto err_disable_sysclk;
> -
>  	clk_disable_unprepare(csi2rx->p_clk);
>  
>  	return 0;
>  
> -err_disable_sysclk:
> -	clk_disable_unprepare(csi2rx->sys_clk);
>  err_disable_pixclk:
>  	for (; i > 0; i--) {
>  		reset_control_assert(csi2rx->pixel_rst[i - 1]);
> @@ -459,9 +448,6 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
>  	reset_control_assert(csi2rx->p_rst);
>  	clk_disable_unprepare(csi2rx->p_clk);
>  
> -	if (v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false))
> -		dev_warn(csi2rx->dev, "Couldn't disable our subdev\n");
> -
>  	if (csi2rx->dphy) {
>  		writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
>  
> @@ -485,38 +471,56 @@ static int csi2rx_log_status(struct v4l2_subdev *sd)
>  	return 0;
>  }
>  
> -static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
> +static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
> +				 struct v4l2_subdev_state *state, u32 pad,
> +				 u64 streams_mask)
>  {
>  	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> -	int ret = 0;
> -
> -	mutex_lock(&csi2rx->lock);
> -
> -	if (enable) {
> -		/*
> -		 * If we're not the first users, there's no need to
> -		 * enable the whole controller.
> -		 */
> -		if (!csi2rx->count) {
> -			ret = csi2rx_start(csi2rx);
> -			if (ret)
> -				goto out;
> -		}
> +	int ret;
>  
> -		csi2rx->count++;
> -	} else {
> -		csi2rx->count--;
> +	/*
> +	 * If we're not the first users, there's no need to
> +	 * enable the whole controller.
> +	 */
> +	if (!csi2rx->count) {
> +		ret = csi2rx_start(csi2rx);
> +		if (ret)
> +			return ret;
> +	}
>  
> -		/*
> -		 * Let the last user turn off the lights.
> -		 */
> +	/* Start streaming on the source */
> +	ret = v4l2_subdev_enable_streams(csi2rx->source_subdev, csi2rx->source_pad,
> +					 BIT(0));

The stream mask is u64, so better use BIT_U64. It doesn't matter here,
but before you know it, you have switched BIT(0) to BIT(foo->bar), and
someone sets bar to 34 and it's broken...

Yes, I see this being changed later, to variable set with BIT_ULL()
(that could be changed to BIT_U64). Nevertheless, better use the correct
macro.

But a bigger issue is if this and patches 6 and 8 are correct or could
be improved.

I think in this one you remove s_stream from cdns-csi2. But the j7
csi2rx is still calling s_stream, so it would fail with this patch. In
patch 8 you switch j7 csi2rx from s_stream to enable_streams. But in
patch 6 you added mutex, locking and s_stream to j7 csi2rx, and in patch
8 you remove that.

Maybe the end result is fine, but it all does feel messy. I think the
patches we should have are:

- Use v4l2_subdev_enable_streams() in j7-csi2rx instead of calling
s_stream. v4l2_subdev_enable_streams() will work with either .s_stream
and .enable_stream in cdns-csi2rx

- Patch 7 (with BIT_64()) to convert cdns-csi2rx

- Patches 6 and 8 combined. You're essentially adding a new subdev, just
do it right from the start with .enable_streams, state, etc., instead of
mutex and s_stream which are removed two patches later.

 Tomi

> +	if (ret) {
> +		dev_err(csi2rx->dev,
> +			"Failed to start streams %d on subdev\n", 0);
>  		if (!csi2rx->count)
>  			csi2rx_stop(csi2rx);
> +		return ret;
>  	}
>  
> -out:
> -	mutex_unlock(&csi2rx->lock);
> -	return ret;
> +	csi2rx->count++;
> +	return 0;
> +}
> +
> +static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
> +				  struct v4l2_subdev_state *state, u32 pad,
> +				  u64 streams_mask)
> +{
> +	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +
> +	if (v4l2_subdev_disable_streams(csi2rx->source_subdev,
> +					csi2rx->source_pad, BIT(0))) {
> +		dev_err(csi2rx->dev, "Couldn't disable our subdev\n");
> +	}
> +
> +	csi2rx->count--;
> +
> +	/* Let the last user turn off the lights. */
> +	if (!csi2rx->count)
> +		csi2rx_stop(csi2rx);
> +
> +	return 0;
>  }
>  
>  static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
> @@ -611,10 +615,8 @@ static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
>  	.enum_mbus_code	= csi2rx_enum_mbus_code,
>  	.get_fmt	= v4l2_subdev_get_fmt,
>  	.set_fmt	= csi2rx_set_fmt,
> -};
> -
> -static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
> -	.s_stream	= csi2rx_s_stream,
> +	.enable_streams         = csi2rx_enable_streams,
> +	.disable_streams        = csi2rx_disable_streams,
>  };
>  
>  static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
> @@ -623,7 +625,6 @@ static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>  
>  static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
>  	.core		= &csi2rx_core_ops,
> -	.video		= &csi2rx_video_ops,
>  	.pad		= &csi2rx_pad_ops,
>  };
>  
> @@ -829,7 +830,6 @@ static int csi2rx_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  	platform_set_drvdata(pdev, csi2rx);
>  	csi2rx->dev = &pdev->dev;
> -	mutex_init(&csi2rx->lock);
>  
>  	ret = csi2rx_get_resources(csi2rx, pdev);
>  	if (ret)

Re: [PATCH v8 12/18] media: cadence: csi2rx: add multistream support

[Tomi Valkeinen]

Hi,

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> From: Jai Luthra <j-luthra@ti.com>
> 
> Cadence CSI-2 bridge IP supports capturing multiple virtual "streams"
> of data over the same physical interface using MIPI Virtual Channels.
> 
> While the hardware IP supports usecases where streams coming in the sink
> pad can be broadcasted to multiple source pads, the driver will need
> significant re-architecture to make that possible. The two users of this
> IP in mainline linux are TI Shim and StarFive JH7110 CAMSS, and both
> have only integrated the first source pad i.e stream0 of this IP. So for
> now keep it simple and only allow 1-to-1 mapping of streams from sink to
> source, without any broadcasting.
> 
> Implement a fallback s_stream hook that internally calls enable_stream
> on each source pad, for consumer drivers that don't use multi-stream

Hmm... So earlier in this series the .s_stream was removed from
cdns-csi2rx. Did that break the "consumer drivers that don't use
multi-stream"? What are those consumers? I assume it means j7-csi2rx and
the above-mentioned starfive camss?

Change the starfive camss to use v4l2_subdev_enable_streams() before the
patch that converts cdns-csi2rx from .s_stream to .enable_stream?

 Tomi

> APIs to still work. The helper function v4l2_subdev_s_stream_helper()
> form the v4l2 framework is not used here as it is meant only for the
> subedvs that have a single source pad and this hardware IP supports
> having multiple source pads.
> 
> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
> Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  drivers/media/platform/cadence/cdns-csi2rx.c | 283 ++++++++++++++++---
>  1 file changed, 236 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 3688077fa8347..833bc134f17cb 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -135,6 +135,7 @@ struct csi2rx_priv {
>  	struct phy			*dphy;
>  
>  	u8				num_pixels[CSI2RX_STREAMS_MAX];
> +	u32				vc_select[CSI2RX_STREAMS_MAX];
>  	u8				lanes[CSI2RX_LANES_MAX];
>  	u8				num_lanes;
>  	u8				max_lanes;
> @@ -273,30 +274,43 @@ static void csi2rx_reset(struct csi2rx_priv *csi2rx)
>  
>  static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
>  {
> -	struct media_pad *src_pad =
> -		&csi2rx->source_subdev->entity.pads[csi2rx->source_pad];
>  	union phy_configure_opts opts = { };
>  	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
> -	struct v4l2_subdev_state *state;
>  	struct v4l2_mbus_framefmt *framefmt;
> +	struct v4l2_subdev_state *state;
>  	const struct csi2rx_fmt *fmt;
> +	int source_pad = csi2rx->source_pad;
> +	struct media_pad *pad = &csi2rx->source_subdev->entity.pads[source_pad];
>  	s64 link_freq;
>  	int ret;
> +	u32 bpp;
>  
>  	state = v4l2_subdev_get_locked_active_state(&csi2rx->subdev);
>  
> -	framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
> -	if (!framefmt) {
> -		dev_err(csi2rx->dev, "Did not find active sink format\n");
> -		return -EINVAL;
> -	}
> +	/*
> +	 * For multi-stream transmitters there is no single pixel rate.
> +	 *
> +	 * In multistream usecase pass bpp as 0 so that v4l2_get_link_freq()
> +	 * returns an error if it falls back to V4L2_CID_PIXEL_RATE.
> +	 */
> +	if (state->routing.num_routes > 1) {
> +		bpp = 0;
> +	} else {
> +		framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
> +		if (!framefmt) {
> +			dev_err(csi2rx->dev, "Did not find active sink format\n");
> +			return -EINVAL;
> +		}
>  
> -	fmt = csi2rx_get_fmt_by_code(framefmt->code);
> +		fmt = csi2rx_get_fmt_by_code(framefmt->code);
> +		bpp = fmt->bpp;
> +	}
>  
> -	link_freq = v4l2_get_link_freq(src_pad,
> -				       fmt->bpp, 2 * csi2rx->num_lanes);
> -	if (link_freq < 0)
> +	link_freq = v4l2_get_link_freq(pad, bpp, 2 * csi2rx->num_lanes);
> +	if (link_freq < 0) {
> +		dev_err(csi2rx->dev, "Unable to calculate link frequency\n");
>  		return link_freq;
> +	}
>  
>  	ret = phy_mipi_dphy_get_default_config_for_hsclk(link_freq,
>  							 csi2rx->num_lanes, cfg);
> @@ -394,11 +408,7 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  					  csi2rx->num_pixels[i]),
>  		       csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
>  
> -		/*
> -		 * Enable one virtual channel. When multiple virtual channels
> -		 * are supported this will have to be changed.
> -		 */
> -		writel(CSI2RX_STREAM_DATA_CFG_VC_SELECT(0),
> +		writel(csi2rx->vc_select[i],
>  		       csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));
>  
>  		writel(CSI2RX_STREAM_CTRL_START,
> @@ -486,18 +496,59 @@ static int csi2rx_log_status(struct v4l2_subdev *sd)
>  	return 0;
>  }
>  
> +static void csi2rx_update_vc_select(struct csi2rx_priv *csi2rx,
> +				    struct v4l2_subdev_state *state)
> +{
> +	struct v4l2_mbus_frame_desc fd = {0};
> +	struct v4l2_subdev_route *route;
> +	unsigned int i;
> +	int ret;
> +
> +	/* Capture VC=0 by default */
> +	for (i = 0; i < CSI2RX_STREAMS_MAX; i++)
> +		csi2rx->vc_select[i] = CSI2RX_STREAM_DATA_CFG_VC_SELECT(0);
> +
> +	ret = csi2rx_get_frame_desc_from_source(csi2rx, &fd);
> +	if (ret || fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
> +		dev_dbg(csi2rx->dev,
> +			"Failed to get source frame desc, allowing only VC=0\n");
> +		return;
> +	}
> +
> +	/* If source provides per-stream VC info, use it to filter by VC */
> +	memset(csi2rx->vc_select, 0, sizeof(csi2rx->vc_select));
> +
> +	for_each_active_route(&state->routing, route) {
> +		u32 cdns_stream = route->source_pad - CSI2RX_PAD_SOURCE_STREAM0;
> +
> +		for (i = 0; i < fd.num_entries; i++) {
> +			if (fd.entry[i].stream != route->sink_stream)
> +				continue;
> +
> +			csi2rx->vc_select[cdns_stream] |=
> +				CSI2RX_STREAM_DATA_CFG_VC_SELECT(fd.entry[i].bus.csi2.vc);
> +		}
> +	}
> +}
> +
>  static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>  				 struct v4l2_subdev_state *state, u32 pad,
>  				 u64 streams_mask)
>  {
>  	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +	u64 sink_streams;
>  	int ret;
>  
> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
> +						       CSI2RX_PAD_SINK,
> +						       &streams_mask);
> +
>  	/*
>  	 * If we're not the first users, there's no need to
>  	 * enable the whole controller.
>  	 */
>  	if (!csi2rx->count) {
> +		csi2rx_update_vc_select(csi2rx, state);
>  		ret = csi2rx_start(csi2rx);
>  		if (ret)
>  			return ret;
> @@ -505,10 +556,11 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>  
>  	/* Start streaming on the source */
>  	ret = v4l2_subdev_enable_streams(csi2rx->source_subdev, csi2rx->source_pad,
> -					 BIT(0));
> +					 sink_streams);
>  	if (ret) {
>  		dev_err(csi2rx->dev,
> -			"Failed to start streams %d on subdev\n", 0);
> +			"Failed to start streams %#llx on subdev\n",
> +			sink_streams);
>  		if (!csi2rx->count)
>  			csi2rx_stop(csi2rx);
>  		return ret;
> @@ -523,9 +575,14 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>  				  u64 streams_mask)
>  {
>  	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +	u64 sink_streams;
> +
> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
> +						       CSI2RX_PAD_SINK,
> +						       &streams_mask);
>  
>  	if (v4l2_subdev_disable_streams(csi2rx->source_subdev,
> -					csi2rx->source_pad, BIT(0))) {
> +						 csi2rx->source_pad, sink_streams)) {
>  		dev_err(csi2rx->dev, "Couldn't disable our subdev\n");
>  	}
>  
> @@ -538,6 +595,36 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>  	return 0;
>  }
>  
> +static int csi2rx_s_stream_fallback(struct v4l2_subdev *sd, int enable)
> +{
> +	struct v4l2_subdev_state *state;
> +	struct v4l2_subdev_route *route;
> +	u64 mask[CSI2RX_PAD_MAX] = {0};
> +	int i, ret;
> +
> +	/* Find the stream mask on all source pads */
> +	state = v4l2_subdev_lock_and_get_active_state(sd);
> +	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
> +		for_each_active_route(&state->routing, route) {
> +			if (route->source_pad == i)
> +				mask[i] |= BIT_ULL(route->source_stream);
> +		}
> +	}
> +	v4l2_subdev_unlock_state(state);
> +
> +	/* Start streaming on each pad */
> +	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
> +		if (enable)
> +			ret = v4l2_subdev_enable_streams(sd, i, mask[i]);
> +		else
> +			ret = v4l2_subdev_disable_streams(sd, i, mask[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return ret;
> +}
> +
>  static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>  				 struct v4l2_subdev_state *state,
>  				 struct v4l2_subdev_mbus_code_enum *code_enum)
> @@ -550,12 +637,56 @@ static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>  	return 0;
>  }
>  
> +static int _csi2rx_set_routing(struct v4l2_subdev *subdev,
> +			       struct v4l2_subdev_state *state,
> +			       struct v4l2_subdev_krouting *routing)
> +{
> +	static const struct v4l2_mbus_framefmt format = {
> +		.width = 640,
> +		.height = 480,
> +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> +		.field = V4L2_FIELD_NONE,
> +		.colorspace = V4L2_COLORSPACE_SRGB,
> +		.ycbcr_enc = V4L2_YCBCR_ENC_601,
> +		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
> +		.xfer_func = V4L2_XFER_FUNC_SRGB,
> +	};
> +	int ret;
> +
> +	if (routing->num_routes > V4L2_FRAME_DESC_ENTRY_MAX)
> +		return -EINVAL;
> +
> +	ret = v4l2_subdev_routing_validate(subdev, routing,
> +					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
> +	if (ret)
> +		return ret;
> +
> +	return v4l2_subdev_set_routing_with_fmt(subdev, state, routing, &format);
> +}
> +
> +static int csi2rx_set_routing(struct v4l2_subdev *subdev,
> +			      struct v4l2_subdev_state *state,
> +			      enum v4l2_subdev_format_whence which,
> +			      struct v4l2_subdev_krouting *routing)
> +{
> +	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +	int ret;
> +
> +	if (which == V4L2_SUBDEV_FORMAT_ACTIVE && csi2rx->count)
> +		return -EBUSY;
> +
> +	ret = _csi2rx_set_routing(subdev, state, routing);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
>  static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>  			  struct v4l2_subdev_state *state,
>  			  struct v4l2_subdev_format *format)
>  {
>  	struct v4l2_mbus_framefmt *fmt;
> -	unsigned int i;
>  
>  	/* No transcoding, source and sink formats must match. */
>  	if (format->pad != CSI2RX_PAD_SINK)
> @@ -567,14 +698,16 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>  	format->format.field = V4L2_FIELD_NONE;
>  
>  	/* Set sink format */
> -	fmt = v4l2_subdev_state_get_format(state, format->pad);
> +	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
>  	*fmt = format->format;
>  
> -	/* Propagate to source formats */
> -	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
> -		fmt = v4l2_subdev_state_get_format(state, i);
> -		*fmt = format->format;
> -	}
> +	/* Propagate to source format */
> +	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
> +							   format->stream);
> +	if (!fmt)
> +		return -EINVAL;
> +
> +	*fmt = format->format;
>  
>  	return 0;
>  }
> @@ -582,21 +715,22 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>  static int csi2rx_init_state(struct v4l2_subdev *subdev,
>  			     struct v4l2_subdev_state *state)
>  {
> -	struct v4l2_subdev_format format = {
> -		.pad = CSI2RX_PAD_SINK,
> -		.format = {
> -			.width = 640,
> -			.height = 480,
> -			.code = MEDIA_BUS_FMT_UYVY8_1X16,
> -			.field = V4L2_FIELD_NONE,
> -			.colorspace = V4L2_COLORSPACE_SRGB,
> -			.ycbcr_enc = V4L2_YCBCR_ENC_601,
> -			.quantization = V4L2_QUANTIZATION_LIM_RANGE,
> -			.xfer_func = V4L2_XFER_FUNC_SRGB,
> +	struct v4l2_subdev_route routes[] = {
> +		{
> +			.sink_pad = CSI2RX_PAD_SINK,
> +			.sink_stream = 0,
> +			.source_pad = CSI2RX_PAD_SOURCE_STREAM0,
> +			.source_stream = 0,
> +			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
>  		},
>  	};
>  
> -	return csi2rx_set_fmt(subdev, state, &format);
> +	struct v4l2_subdev_krouting routing = {
> +		.num_routes = ARRAY_SIZE(routes),
> +		.routes = routes,
> +	};
> +
> +	return _csi2rx_set_routing(subdev, state, &routing);
>  }
>  
>  int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
> @@ -630,17 +764,70 @@ static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
>  				 struct v4l2_mbus_frame_desc *fd)
>  {
>  	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +	struct v4l2_mbus_frame_desc source_fd = {0};
> +	struct v4l2_subdev_route *route;
> +	struct v4l2_subdev_state *state;
> +	int ret;
> +
> +	ret = csi2rx_get_frame_desc_from_source(csi2rx, &source_fd);
> +	if (ret)
> +		return ret;
> +
> +	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
> +
> +	state = v4l2_subdev_lock_and_get_active_state(subdev);
> +
> +	for_each_active_route(&state->routing, route) {
> +		struct v4l2_mbus_frame_desc_entry *source_entry = NULL;
> +		unsigned int i;
> +
> +		if (route->source_pad != pad)
> +			continue;
> +
> +		for (i = 0; i < source_fd.num_entries; i++) {
> +			if (source_fd.entry[i].stream == route->sink_stream) {
> +				source_entry = &source_fd.entry[i];
> +				break;
> +			}
> +		}
> +
> +		if (!source_entry) {
> +			dev_err(csi2rx->dev,
> +				"Failed to find stream from source frame desc\n");
> +			ret = -EPIPE;
> +			goto err_missing_stream;
> +		}
> +
> +		fd->entry[fd->num_entries].stream = route->source_stream;
> +		fd->entry[fd->num_entries].flags = source_entry->flags;
> +		fd->entry[fd->num_entries].length = source_entry->length;
> +		fd->entry[fd->num_entries].pixelcode = source_entry->pixelcode;
> +		fd->entry[fd->num_entries].bus.csi2.vc =
> +			source_entry->bus.csi2.vc;
> +		fd->entry[fd->num_entries].bus.csi2.dt =
> +			source_entry->bus.csi2.dt;
> +
> +		fd->num_entries++;
> +	}
> +
> +err_missing_stream:
> +	v4l2_subdev_unlock_state(state);
>  
> -	return csi2rx_get_frame_desc_from_source(csi2rx, fd);
> +	return ret;
>  }
>  
>  static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
> -	.enum_mbus_code	= csi2rx_enum_mbus_code,
> -	.get_fmt	= v4l2_subdev_get_fmt,
> -	.set_fmt	= csi2rx_set_fmt,
> -	.enable_streams         = csi2rx_enable_streams,
> -	.disable_streams        = csi2rx_disable_streams,
> -	.get_frame_desc	= csi2rx_get_frame_desc,
> +	.enum_mbus_code		= csi2rx_enum_mbus_code,
> +	.get_fmt		= v4l2_subdev_get_fmt,
> +	.set_fmt		= csi2rx_set_fmt,
> +	.get_frame_desc		= csi2rx_get_frame_desc,
> +	.set_routing		= csi2rx_set_routing,
> +	.enable_streams		= csi2rx_enable_streams,
> +	.disable_streams	= csi2rx_disable_streams,
> +};
> +
> +static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
> +	.s_stream	= csi2rx_s_stream_fallback,
>  };
>  
>  static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
> @@ -649,6 +836,7 @@ static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>  
>  static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
>  	.core		= &csi2rx_core_ops,
> +	.video		= &csi2rx_video_ops,
>  	.pad		= &csi2rx_pad_ops,
>  };
>  
> @@ -876,7 +1064,8 @@ static int csi2rx_probe(struct platform_device *pdev)
>  	csi2rx->pads[CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>  	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
>  		csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
> -	csi2rx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	csi2rx->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE |
> +		V4L2_SUBDEV_FL_STREAMS;
>  	csi2rx->subdev.entity.ops = &csi2rx_media_ops;
>  
>  	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,

Re: [PATCH v8 17/18] media: ti: j721e-csi2rx: Support runtime suspend

[Sakari Ailus]

Hi Rishikesh,

On Wed, Nov 12, 2025 at 05:24:58PM +0530, Rishikesh Donadkar wrote:
> From: Jai Luthra <jai.luthra@ideasonboard.com>
> 
> Add support for runtime power-management to enable powering off the
> shared power domain between Cadence CSI2RX and TI CSI2RX wrapper when
> the device(s) are not in use.
> 
> When powering off the IP, the PSI-L endpoint loses the paired DMA
> channels. Thus we have to release the DMA channels at runtime suspend
> and request them again at resume.
> 
> Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  drivers/media/platform/ti/Kconfig             |  1 +
>  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 55 ++++++++++++++++++-
>  2 files changed, 54 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
> index 3bc4aa35887e6..a808063e24779 100644
> --- a/drivers/media/platform/ti/Kconfig
> +++ b/drivers/media/platform/ti/Kconfig
> @@ -70,6 +70,7 @@ config VIDEO_TI_J721E_CSI2RX
>  	depends on VIDEO_CADENCE_CSI2RX
>  	depends on PHY_CADENCE_DPHY_RX || COMPILE_TEST
>  	depends on ARCH_K3 || COMPILE_TEST
> +	depends on PM
>  	select VIDEOBUF2_DMA_CONTIG
>  	select V4L2_FWNODE
>  	help
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> index 528041ee78cf3..21e032c64b901 100644
> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> @@ -13,6 +13,7 @@
>  #include <linux/module.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/property.h>
>  
>  #include <media/cadence/cdns-csi2rx.h>
> @@ -963,12 +964,16 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	unsigned long flags;
>  	int ret = 0;
>  
> +	ret = pm_runtime_resume_and_get(csi->dev);
> +	if (ret)
> +		return ret;
> +
>  	spin_lock_irqsave(&dma->lock, flags);
>  	if (list_empty(&dma->queue))
>  		ret = -EIO;
>  	spin_unlock_irqrestore(&dma->lock, flags);
>  	if (ret)
> -		return ret;
> +		goto err;
>  
>  	ret = video_device_pipeline_start(&ctx->vdev, &csi->pipe);
>  	if (ret)
> @@ -1024,6 +1029,8 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
>  err:
>  	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
> +	pm_runtime_put(csi->dev);
> +
>  	return ret;
>  }
>  
> @@ -1055,6 +1062,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
>  
>  	ti_csi2rx_stop_dma(ctx);
>  	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
> +	pm_runtime_put(csi->dev);
>  }
>  
>  static const struct vb2_ops csi_vb2_qops = {
> @@ -1261,7 +1269,9 @@ static void ti_csi2rx_cleanup_notifier(struct ti_csi2rx_dev *csi)
>  
>  static void ti_csi2rx_cleanup_ctx(struct ti_csi2rx_ctx *ctx)
>  {
> -	dma_release_channel(ctx->dma.chan);
> +	if (!pm_runtime_status_suspended(ctx->csi->dev))

What's the motivation for this change? Do the DMA channel need to be
released only if the device's RPM status isn't suspended?

Is there a guarantee Runtime PM is disabled when the function is called?
Otherwise there's no guarantee state change couldn't occur.

> +		dma_release_channel(ctx->dma.chan);
> +
>  	vb2_queue_release(&ctx->vidq);
>  
>  	video_unregister_device(&ctx->vdev);
> @@ -1512,6 +1522,39 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
>  	return ret;
>  }
>  
> +static int ti_csi2rx_runtime_suspend(struct device *dev)
> +{
> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> +	int i;
> +
> +	if (csi->enable_count != 0)
> +		return -EBUSY;
> +
> +	for (i = 0; i < csi->num_ctx; i++)
> +		dma_release_channel(csi->ctx[i].dma.chan);
> +
> +	return 0;
> +}
> +
> +static int ti_csi2rx_runtime_resume(struct device *dev)
> +{
> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> +	int ret, i;
> +
> +	for (i = 0; i < csi->num_ctx; i++) {

You could declare i (as unsigned int) here.

The same for ret actually.

> +		ret = ti_csi2rx_init_dma(&csi->ctx[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops ti_csi2rx_pm_ops = {
> +	RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
> +		       NULL)
> +};
> +
>  static int ti_csi2rx_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np = pdev->dev.of_node;
> @@ -1579,6 +1622,10 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
>  		goto err_notifier;
>  	}
>  
> +	pm_runtime_set_active(csi->dev);
> +	pm_runtime_enable(csi->dev);

Note that the sub-device driver's UAPI may be already available to users
when the async sub-device is registered. Therefore you'll need enable
runtime PM before that.

> +	pm_request_idle(csi->dev);
> +
>  	return 0;
>  
>  err_notifier:
> @@ -1609,6 +1656,9 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
>  	mutex_destroy(&csi->mutex);
>  	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
>  			  csi->drain.paddr);

Is there a guarantee the device is in a particular runtime PM state here,
e.g. suspended?

> +	pm_runtime_disable(&pdev->dev);
> +	pm_runtime_set_suspended(&pdev->dev);
> +
>  }
>  
>  static const struct of_device_id ti_csi2rx_of_match[] = {
> @@ -1623,6 +1673,7 @@ static struct platform_driver ti_csi2rx_pdrv = {
>  	.driver = {
>  		.name = TI_CSI2RX_MODULE_NAME,
>  		.of_match_table = ti_csi2rx_of_match,
> +		.pm		= &ti_csi2rx_pm_ops,
>  	},
>  };
>  

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v8 06/18] media: ti: j721e-csi2rx: add a subdev for the core device

[Rishikesh Donadkar]

On 20/11/25 18:09, Sakari Ailus wrote:
> Hi Rishikesh,


Hi Sakari,

Thank you for the review.

>
> On Wed, Nov 12, 2025 at 05:24:47PM +0530, Rishikesh Donadkar wrote:
>> +static int ti_csi2rx_sd_s_stream(struct v4l2_subdev *sd, int enable)
> Could you instead implement enable_streams and disable_streams pad ops,
> please, and use v4l2_subdev_enable_streams() from there?


This is done in 08/18, I will merge changes form 08/18 in to this patch.

Rishikesh

>
>> +{
>> +	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
>> +	int ret = 0;
>> +
>> +	mutex_lock(&csi->mutex);
>> +
>> +	if (enable) {
>> +		if (csi->enable_count > 0) {
>> +			csi->enable_count++;
>> +			goto out;
>> +		}
>> +
>> +		ret = v4l2_subdev_call(csi->source, video, s_stream, 1);
>> +		if (ret)
>> +			goto out;
>> +
>> +		csi->enable_count++;
>> +	} else {
>> +		if (csi->enable_count == 0) {
>> +			ret = -EINVAL;
>> +			goto out;
>> +		}
>> +
>> +		if (--csi->enable_count > 0)
>> +			goto out;
>> +
>> +		ret = v4l2_subdev_call(csi->source, video, s_stream, 0);
>> +	}
>> +
>> +out:
>> +	mutex_unlock(&csi->mutex);
>> +	return ret;
>> +}

Re: [PATCH v8 07/18] media: cadence: csi2rx: Move to .enable/disable_streams API

[Rishikesh Donadkar]

On 20/11/25 18:30, Tomi Valkeinen wrote:
> Hi,


Hi Tomi

>
> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
>> The enable_streams() API in v4l2 supports passing a bitmask to enable
>> each pad/stream combination individually on any media subdev. Use this
>> API instead of  s_stream() API.
>>
>> Implement the enable_stream and disable_stream hooks in place of the
>> stream-unaware s_stream hook.
>>
>> Remove the lock that was used to serialize stream starts/stops which
>> is not required anymore since the v4l2-core serializes the
>> enable/disable_streams() calls for the subdev.
>>
>> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> ---
>>   drivers/media/platform/cadence/cdns-csi2rx.c | 108 +++++++++----------
>>   1 file changed, 54 insertions(+), 54 deletions(-)
>>
>> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
>> index 8c19f125da3e5..34da81893308b 100644
>> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
>> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
>> @@ -125,12 +125,6 @@ struct csi2rx_priv {
>>   	unsigned int			count;
>>   	int				error_irq;
>>   
>> -	/*
>> -	 * Used to prevent race conditions between multiple,
>> -	 * concurrent calls to start and stop.
>> -	 */
>> -	struct mutex			lock;
>> -
>>   	void __iomem			*base;
>>   	struct clk			*sys_clk;
>>   	struct clk			*p_clk;
>> @@ -268,20 +262,21 @@ static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
>>   		&csi2rx->source_subdev->entity.pads[csi2rx->source_pad];
>>   	union phy_configure_opts opts = { };
>>   	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
>> -	struct v4l2_subdev_format sd_fmt = {
>> -		.which	= V4L2_SUBDEV_FORMAT_ACTIVE,
>> -		.pad	= CSI2RX_PAD_SINK,
>> -	};
>> +	struct v4l2_subdev_state *state;
>> +	struct v4l2_mbus_framefmt *framefmt;
>>   	const struct csi2rx_fmt *fmt;
>>   	s64 link_freq;
>>   	int ret;
>>   
>> -	ret = v4l2_subdev_call_state_active(&csi2rx->subdev, pad, get_fmt,
>> -					    &sd_fmt);
>> -	if (ret < 0)
>> -		return ret;
>> +	state = v4l2_subdev_get_locked_active_state(&csi2rx->subdev);
>>   
>> -	fmt = csi2rx_get_fmt_by_code(sd_fmt.format.code);
>> +	framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
>> +	if (!framefmt) {
>> +		dev_err(csi2rx->dev, "Did not find active sink format\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	fmt = csi2rx_get_fmt_by_code(framefmt->code);
>>   
>>   	link_freq = v4l2_get_link_freq(src_pad,
>>   				       fmt->bpp, 2 * csi2rx->num_lanes);
>> @@ -401,16 +396,10 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>>   
>>   	reset_control_deassert(csi2rx->sys_rst);
>>   
>> -	ret = v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, true);
>> -	if (ret)
>> -		goto err_disable_sysclk;
>> -
>>   	clk_disable_unprepare(csi2rx->p_clk);
>>   
>>   	return 0;
>>   
>> -err_disable_sysclk:
>> -	clk_disable_unprepare(csi2rx->sys_clk);
>>   err_disable_pixclk:
>>   	for (; i > 0; i--) {
>>   		reset_control_assert(csi2rx->pixel_rst[i - 1]);
>> @@ -459,9 +448,6 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
>>   	reset_control_assert(csi2rx->p_rst);
>>   	clk_disable_unprepare(csi2rx->p_clk);
>>   
>> -	if (v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false))
>> -		dev_warn(csi2rx->dev, "Couldn't disable our subdev\n");
>> -
>>   	if (csi2rx->dphy) {
>>   		writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
>>   
>> @@ -485,38 +471,56 @@ static int csi2rx_log_status(struct v4l2_subdev *sd)
>>   	return 0;
>>   }
>>   
>> -static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
>> +static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>> +				 struct v4l2_subdev_state *state, u32 pad,
>> +				 u64 streams_mask)
>>   {
>>   	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> -	int ret = 0;
>> -
>> -	mutex_lock(&csi2rx->lock);
>> -
>> -	if (enable) {
>> -		/*
>> -		 * If we're not the first users, there's no need to
>> -		 * enable the whole controller.
>> -		 */
>> -		if (!csi2rx->count) {
>> -			ret = csi2rx_start(csi2rx);
>> -			if (ret)
>> -				goto out;
>> -		}
>> +	int ret;
>>   
>> -		csi2rx->count++;
>> -	} else {
>> -		csi2rx->count--;
>> +	/*
>> +	 * If we're not the first users, there's no need to
>> +	 * enable the whole controller.
>> +	 */
>> +	if (!csi2rx->count) {
>> +		ret = csi2rx_start(csi2rx);
>> +		if (ret)
>> +			return ret;
>> +	}
>>   
>> -		/*
>> -		 * Let the last user turn off the lights.
>> -		 */
>> +	/* Start streaming on the source */
>> +	ret = v4l2_subdev_enable_streams(csi2rx->source_subdev, csi2rx->source_pad,
>> +					 BIT(0));
> The stream mask is u64, so better use BIT_U64. It doesn't matter here,
> but before you know it, you have switched BIT(0) to BIT(foo->bar), and
> someone sets bar to 34 and it's broken...
>
> Yes, I see this being changed later, to variable set with BIT_ULL()
> (that could be changed to BIT_U64). Nevertheless, better use the correct
> macro.


Sure, I will change it in the next revision.

>
> But a bigger issue is if this and patches 6 and 8 are correct or could
> be improved.
>
> I think in this one you remove s_stream from cdns-csi2. But the j7
> csi2rx is still calling s_stream, so it would fail with this patch. In
> patch 8 you switch j7 csi2rx from s_stream to enable_streams. But in
> patch 6 you added mutex, locking and s_stream to j7 csi2rx, and in patch
> 8 you remove that.
>
> Maybe the end result is fine, but it all does feel messy. I think the
> patches we should have are:
>
> - Use v4l2_subdev_enable_streams() in j7-csi2rx instead of calling
> s_stream. v4l2_subdev_enable_streams() will work with either .s_stream
> and .enable_stream in cdns-csi2rx
>
> - Patch 7 (with BIT_64()) to convert cdns-csi2rx
>
> - Patches 6 and 8 combined. You're essentially adding a new subdev, just
> do it right from the start with .enable_streams, state, etc., instead of
> mutex and s_stream which are removed two patches later.


Right, I will merge changes from 08/18 into 06/18.


Thanks,

Rishikesh

>
>   Tomi
>
>> +	if (ret) {
>> +		dev_err(csi2rx->dev,
>> +			"Failed to start streams %d on subdev\n", 0);
>>   		if (!csi2rx->count)
>>   			csi2rx_stop(csi2rx);
>> +		return ret;
>>   	}
>>   
>> -out:
>> -	mutex_unlock(&csi2rx->lock);
>> -	return ret;
>> +	csi2rx->count++;
>> +	return 0;
>> +}
>> +
>> +static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>> +				  struct v4l2_subdev_state *state, u32 pad,
>> +				  u64 streams_mask)
>> +{
>> +	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +
>> +	if (v4l2_subdev_disable_streams(csi2rx->source_subdev,
>> +					csi2rx->source_pad, BIT(0))) {
>> +		dev_err(csi2rx->dev, "Couldn't disable our subdev\n");
>> +	}
>> +
>> +	csi2rx->count--;
>> +
>> +	/* Let the last user turn off the lights. */
>> +	if (!csi2rx->count)
>> +		csi2rx_stop(csi2rx);
>> +
>> +	return 0;
>>   }
>>   
>>   static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>> @@ -611,10 +615,8 @@ static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
>>   	.enum_mbus_code	= csi2rx_enum_mbus_code,
>>   	.get_fmt	= v4l2_subdev_get_fmt,
>>   	.set_fmt	= csi2rx_set_fmt,
>> -};
>> -
>> -static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
>> -	.s_stream	= csi2rx_s_stream,
>> +	.enable_streams         = csi2rx_enable_streams,
>> +	.disable_streams        = csi2rx_disable_streams,
>>   };
>>   
>>   static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>> @@ -623,7 +625,6 @@ static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>>   
>>   static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
>>   	.core		= &csi2rx_core_ops,
>> -	.video		= &csi2rx_video_ops,
>>   	.pad		= &csi2rx_pad_ops,
>>   };
>>   
>> @@ -829,7 +830,6 @@ static int csi2rx_probe(struct platform_device *pdev)
>>   		return -ENOMEM;
>>   	platform_set_drvdata(pdev, csi2rx);
>>   	csi2rx->dev = &pdev->dev;
>> -	mutex_init(&csi2rx->lock);
>>   
>>   	ret = csi2rx_get_resources(csi2rx, pdev);
>>   	if (ret)

Re: [PATCH v8 08/18] media: ti: j721e-csi2rx: Move to .enable/disable_streams API

[Rishikesh Donadkar]

On 20/11/25 18:10, Sakari Ailus wrote:
> On Wed, Nov 12, 2025 at 05:24:49PM +0530, Rishikesh Donadkar wrote:
>> Support the new enable_stream()/disable_stream() APIs in the subdev
>> instead of s_stream() hook.
>>
>> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> This addresses my comment on the 6th patch.
>
> Shouldn't this be merged to that?

Sure, I will do that.


Rishikesh

>

Re: [PATCH v8 11/18] media: ti: j721e-csi2rx: add support for processing virtual channels

[Rishikesh Donadkar]

On 20/11/25 18:02, Tomi Valkeinen wrote:
> Hi,


Hi Tomi,

>
> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
>> From: Jai Luthra <j-luthra@ti.com>
>>
>> Use get_frame_desc() to get the frame desc from the connected source,
>> and use the provided virtual channel instead of hardcoded one.
> So this baffled me a bit: the code seems to get the VC from the frame
> desc, but not the DT. But it looks like the DT values are hardcoded in
> the driver's formats table, and those are used for DT filtering.


Previous to this, we were using default VC 0(hard coded), In this patch 
we change it to use the one returned by the get_frame_desc(). I will 
edit the commit message to mention this properly.

Yes, to filter on the basis of DT we use the DT form the the driver's 
format table.

>
> We need to do something like that for legacy cases where the source does
> not support get_frame_desc, but if there is a frame desc, we should use
> the DT and VC from the frame desc.


Sure, I will change this in the next revision.

>
>> get_frame_desc() returns the same information when called on each stream
>> start, so instead get the VCs for all the routed stream at first
>> stream start and cache this information in the driver.
> I get the point but... There isn't anything like this in the patch?


Thanks for pointing out, I moved the code to do this in the patch 13/18 
between v7->v8. I will remove this form the commit message.

>
>> get_frame_desc() works per stream, but as we don't support multiple
> "get_frame_desc() works per stream", what does it mean? It returns all
> the streams for a pad.


This means that get_frame_desc() works for single stream use case as 
well, I will change the commit message.

>
>> streams yet, we will just always use stream 0. If the source doesn't
>> support get_frame_desc(), fall back to the previous method of always
>> capturing virtual channel 0.
> Right, if there's no frame desc (and we need to support legacy drivers),
> the driver should default to VC=0, DT from the formats table. But as
> mentioned above, VC and DT should normally come from the frame desc. It


I will change this in the next revision.


Rishikesh

> would be good to have a separate "legacy" function/branch/something, so
> that we clearly distinguish the legacy and frame-desc cases.
>
>   Tomi
>
>> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
>> Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
>> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
>> Signed-off-by: Jai Luthra <j-luthra@ti.com>
>> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> ---
>>   .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 38 +++++++++++++++++++
>>   1 file changed, 38 insertions(+)
>>
>> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> index 5c4524bf42e6e..126a62fa2c4c4 100644
>> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> @@ -32,6 +32,7 @@
>>   #define SHIM_DMACNTX_YUV422		GENMASK(27, 26)
>>   #define SHIM_DMACNTX_DUAL_PCK_CFG	BIT(24)
>>   #define SHIM_DMACNTX_SIZE		GENMASK(21, 20)
>> +#define SHIM_DMACNTX_VC			GENMASK(9, 6)
>>   #define SHIM_DMACNTX_FMT		GENMASK(5, 0)
>>   #define SHIM_DMACNTX_YUV422_MODE_11	3
>>   #define SHIM_DMACNTX_SIZE_8		0
>> @@ -110,6 +111,8 @@ struct ti_csi2rx_ctx {
>>   	struct media_pad		pad;
>>   	u32				sequence;
>>   	u32				idx;
>> +	u32				vc;
>> +	u32				stream;
>>   };
>>   
>>   struct ti_csi2rx_dev {
>> @@ -610,6 +613,7 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
>>   	}
>>   
>>   	reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
>> +	reg |= FIELD_PREP(SHIM_DMACNTX_VC, ctx->vc);
>>   
>>   	writel(reg, csi->shim + SHIM_DMACNTX(ctx->idx));
>>   
>> @@ -884,6 +888,32 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
>>   	}
>>   }
>>   
>> +static int ti_csi2rx_get_vc(struct ti_csi2rx_ctx *ctx)
>> +{
>> +	struct ti_csi2rx_dev *csi = ctx->csi;
>> +	struct v4l2_mbus_frame_desc fd;
>> +	struct media_pad *pad;
>> +	int ret, i;
>> +
>> +	pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
>> +	if (!pad)
>> +		return -ENODEV;
>> +
>> +	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, pad->index, &fd);
>> +	if (ret)
>> +		return ret;
>> +
>> +	if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
>> +		return -EINVAL;
>> +
>> +	for (i = 0; i < fd.num_entries; i++) {
>> +		if (ctx->stream == fd.entry[i].stream)
>> +			return fd.entry[i].bus.csi2.vc;
>> +	}
>> +
>> +	return -ENODEV;
>> +}
>> +
>>   static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>>   {
>>   	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
>> @@ -904,6 +934,14 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>>   	if (ret)
>>   		goto err;
>>   
>> +	ret = ti_csi2rx_get_vc(ctx);
>> +	if (ret == -ENOIOCTLCMD)
>> +		ctx->vc = 0;
>> +	else if (ret < 0)
>> +		goto err;
>> +	else
>> +		ctx->vc = ret;
>> +
>>   	ti_csi2rx_setup_shim(ctx);
>>   
>>   	ctx->sequence = 0;

Re: [PATCH v8 13/18] media: ti: j721e-csi2rx: add multistream support

[Tomi Valkeinen]

Hi,

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> From: Jai Luthra <j-luthra@ti.com>
> 
> Each CSI2 stream can be multiplexed into 4 independent streams, each

Well, that's not true, at least generally speaking (there can be more
than 4). Is that specific to TI hardware?

> identified by its virtual channel number and data type. The incoming
> data from these streams can be filtered on the basis of either the
> virtual channel or the data type.
> 
> To capture this multiplexed stream, the application needs to tell
> the driver how it wants to route the data. It needs to specify
> which context should process which stream. This is done via the
> new routing APIs.
> 
> Add ioctls to accept routing information from the application and save
> that in the driver. This can be used when starting streaming on a
> context to determine which route and consequently which virtual channel
> it should process.
> 
> De-assert the pixel interface reset on first start_streaming() and assert
> it on the last stop_streaming().
> 
> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
> Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 224 ++++++++++++++----
>  1 file changed, 179 insertions(+), 45 deletions(-)
> 
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> index 126a62fa2c4c4..c8e0e761f2802 100644
> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> @@ -103,6 +103,7 @@ struct ti_csi2rx_dev;
>  
>  struct ti_csi2rx_ctx {
>  	struct ti_csi2rx_dev		*csi;
> +	struct v4l2_subdev_route        *route;
>  	struct video_device		vdev;
>  	struct vb2_queue		vidq;
>  	struct mutex			mutex; /* To serialize ioctls. */
> @@ -136,6 +137,7 @@ struct ti_csi2rx_dev {
>  		dma_addr_t		paddr;
>  		size_t			len;
>  	} drain;
> +	bool                            vc_cached;
>  };
>  
>  static inline struct ti_csi2rx_dev *to_csi2rx_dev(struct v4l2_subdev *sd)
> @@ -143,17 +145,6 @@ static inline struct ti_csi2rx_dev *to_csi2rx_dev(struct v4l2_subdev *sd)
>  	return container_of(sd, struct ti_csi2rx_dev, subdev);
>  }
>  
> -static const struct v4l2_mbus_framefmt ti_csi2rx_default_fmt = {
> -	.width = 640,
> -	.height = 480,
> -	.code = MEDIA_BUS_FMT_UYVY8_1X16,
> -	.field = V4L2_FIELD_NONE,
> -	.colorspace = V4L2_COLORSPACE_SRGB,
> -	.ycbcr_enc = V4L2_YCBCR_ENC_601,
> -	.quantization = V4L2_QUANTIZATION_LIM_RANGE,
> -	.xfer_func = V4L2_XFER_FUNC_SRGB,
> -};
> -
>  static const struct ti_csi2rx_fmt ti_csi2rx_formats[] = {
>  	{
>  		.fourcc			= V4L2_PIX_FMT_YUYV,
> @@ -566,8 +557,10 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
>  	fmt = find_format_by_fourcc(ctx->v_fmt.fmt.pix.pixelformat);
>  
>  	/* De-assert the pixel interface reset. */
> -	reg = SHIM_CNTL_PIX_RST;
> -	writel(reg, csi->shim + SHIM_CNTL);
> +	if (!csi->enable_count) {
> +		reg = SHIM_CNTL_PIX_RST;
> +		writel(reg, csi->shim + SHIM_CNTL);
> +	}
>  
>  	/* Negotiate pixel count from the source */
>  	ti_csi2rx_request_max_ppc(csi);
> @@ -888,30 +881,80 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
>  	}
>  }
>  
> +static int ti_csi2rx_get_route(struct ti_csi2rx_ctx *ctx)
> +{
> +	struct ti_csi2rx_dev *csi = ctx->csi;
> +	struct media_pad *pad;
> +	struct v4l2_subdev_state *state;
> +	struct v4l2_subdev_route *r;
> +
> +	/* Get the source pad connected to this ctx */
> +	pad = media_entity_remote_source_pad_unique(ctx->pad.entity);
> +	if (!pad) {
> +		dev_err(csi->dev, "No pad connected to ctx %d\n", ctx->idx);
> +		return -ENODEV;
> +	}
> +
> +	state = v4l2_subdev_lock_and_get_active_state(&csi->subdev);

This looks a bit concerning. You lock the state, find the correct route
and store a pointer to the route into the ctx, then unlock the state...
Alarm bells should be ringing here.

> +
> +	for_each_active_route(&state->routing, r) {
> +		if (!(r->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE))

for_each_active_route() already checks this ("_active_").

> +			continue;
> +		if (r->source_pad != pad->index)
> +			continue;
> +
> +		ctx->route = r;

Shouldn't you break here?

> +	}
> +
> +	v4l2_subdev_unlock_state(state);
> +
> +	if (!ctx->route)
> +		return -ENODEV;
> +
> +	return 0;
> +}
> +
>  static int ti_csi2rx_get_vc(struct ti_csi2rx_ctx *ctx)
>  {
>  	struct ti_csi2rx_dev *csi = ctx->csi;
> +	struct ti_csi2rx_ctx *curr_ctx;
>  	struct v4l2_mbus_frame_desc fd;
> -	struct media_pad *pad;
> -	int ret, i;
> +	struct media_pad *source_pad;
> +	struct v4l2_subdev_route *curr_route;
> +	int ret;
> +	unsigned int i, j;
>  
> -	pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
> -	if (!pad)
> +	/* Get the frame desc form source */
> +	source_pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
> +	if (!source_pad)
>  		return -ENODEV;
>  
> -	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, pad->index, &fd);
> +	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, source_pad->index, &fd);
>  	if (ret)
>  		return ret;
>  
>  	if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
>  		return -EINVAL;
>  
> -	for (i = 0; i < fd.num_entries; i++) {
> -		if (ctx->stream == fd.entry[i].stream)
> -			return fd.entry[i].bus.csi2.vc;
> +	for (i = 0; i < csi->num_ctx; i++) {
> +		curr_ctx = &csi->ctx[i];
> +
> +		/* Capture VC 0 by default */
> +		curr_ctx->vc = 0;
> +
> +		ret = ti_csi2rx_get_route(curr_ctx);
> +		if (ret)
> +			continue;
> +
> +		curr_route = curr_ctx->route;
> +		curr_ctx->stream = curr_route->sink_stream;
> +
> +		for (j = 0; j < fd.num_entries; j++)
> +			if (curr_ctx->stream == fd.entry[j].stream)
> +				curr_ctx->vc = fd.entry[j].bus.csi2.vc;
>  	}
>  
> -	return -ENODEV;
> +	return 0;
>  }
>  
>  static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> @@ -934,13 +977,24 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	if (ret)
>  		goto err;
>  
> -	ret = ti_csi2rx_get_vc(ctx);
> -	if (ret == -ENOIOCTLCMD)
> -		ctx->vc = 0;
> -	else if (ret < 0)
> +	/* If no stream is routed to this ctx, exit early */
> +	ret = ti_csi2rx_get_route(ctx);
> +	if (ret)
>  		goto err;
> -	else
> -		ctx->vc = ret;
> +
> +	/* Get the VC for all enabled ctx on first stream start */

Is the comment right? How does this work? ti_csi2rx_get_vc() is passed a
single context, but... it gets VCs for all contexts? And shouldn't these
also be dealing with DT at the same time with VC?

> +	mutex_lock(&csi->mutex);
> +	if (!csi->vc_cached) {
> +		ret = ti_csi2rx_get_vc(ctx);
> +		if (ret == -ENOIOCTLCMD) {
> +			ctx->vc = 0;
> +		} else if (ret < 0) {
> +			mutex_unlock(&csi->mutex);
> +			goto err;
> +		}
> +		csi->vc_cached = true;
> +	}
> +	mutex_unlock(&csi->mutex);
>  
>  	ti_csi2rx_setup_shim(ctx);
>  
> @@ -960,8 +1014,9 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	dma->state = TI_CSI2RX_DMA_ACTIVE;
>  	spin_unlock_irqrestore(&dma->lock, flags);
>  
> +	/* Start stream 0, we don't allow multiple streams on the source pad */
>  	ret = v4l2_subdev_enable_streams(&csi->subdev,
> -					 TI_CSI2RX_PAD_FIRST_SOURCE,
> +					 TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
>  					 BIT(0));
>  	if (ret)
>  		goto err_dma;
> @@ -985,17 +1040,26 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
>  	struct ti_csi2rx_dev *csi = ctx->csi;
>  	int ret;
>  
> -	video_device_pipeline_stop(&ctx->vdev);
> +	mutex_lock(&csi->mutex);
>  
> -	writel(0, csi->shim + SHIM_CNTL);
>  	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
>  
> +	/* assert pixel reset to prevent stale data */
> +	if (csi->enable_count == 1) {
> +		writel(0, csi->shim + SHIM_CNTL);
> +		csi->vc_cached = false;
> +	}
> +
> +	video_device_pipeline_stop(&ctx->vdev);
> +
>  	ret = v4l2_subdev_disable_streams(&csi->subdev,
> -					  TI_CSI2RX_PAD_FIRST_SOURCE,
> +					  TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
>  					  BIT(0));
>  	if (ret)
>  		dev_err(csi->dev, "Failed to stop subdev stream\n");
>  
> +	mutex_unlock(&csi->mutex);
> +
>  	ti_csi2rx_stop_dma(ctx);
>  	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
>  }
> @@ -1038,25 +1102,84 @@ static int ti_csi2rx_sd_set_fmt(struct v4l2_subdev *sd,
>  	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
>  	*fmt = format->format;
>  
> -	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE,
> -					   format->stream);
> +	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
> +							   format->stream);
> +	if (!fmt)
> +		return -EINVAL;
> +
>  	*fmt = format->format;
>  
>  	return 0;
>  }
>  
> -static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
> -				   struct v4l2_subdev_state *state)
> +static int _ti_csi2rx_sd_set_routing(struct v4l2_subdev *sd,
> +				     struct v4l2_subdev_state *state,
> +				     struct v4l2_subdev_krouting *routing)
>  {
> -	struct v4l2_mbus_framefmt *fmt;
> +	int ret;
>  
> -	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_SINK);
> -	*fmt = ti_csi2rx_default_fmt;
> +	const struct v4l2_mbus_framefmt format = {

"static const"

> +		.width = 640,
> +		.height = 480,
> +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> +		.field = V4L2_FIELD_NONE,
> +		.colorspace = V4L2_COLORSPACE_SRGB,
> +		.ycbcr_enc = V4L2_YCBCR_ENC_601,
> +		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
> +		.xfer_func = V4L2_XFER_FUNC_SRGB,
> +	};
>  
> -	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE);
> -	*fmt = ti_csi2rx_default_fmt;
> +	ret = v4l2_subdev_routing_validate(sd, routing,
> +					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1 |
> +					   V4L2_SUBDEV_ROUTING_NO_SOURCE_MULTIPLEXING);
>  
> -	return 0;
> +	if (ret)
> +		return ret;
> +
> +	/* Only stream ID 0 allowed on source pads */
> +	for (unsigned int i = 0; i < routing->num_routes; ++i) {
> +		const struct v4l2_subdev_route *route = &routing->routes[i];
> +
> +		if (route->source_stream != 0)
> +			return -EINVAL;
> +	}
> +
> +	ret = v4l2_subdev_set_routing_with_fmt(sd, state, routing, &format);
> +
> +	return ret;
> +}
> +
> +static int ti_csi2rx_sd_set_routing(struct v4l2_subdev *sd,
> +				    struct v4l2_subdev_state *state,
> +				    enum v4l2_subdev_format_whence which,
> +				    struct v4l2_subdev_krouting *routing)
> +{
> +	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
> +
> +	if (csi->enable_count > 0)
> +		return -EBUSY;
> +
> +	return _ti_csi2rx_sd_set_routing(sd, state, routing);
> +}
> +
> +static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
> +				   struct v4l2_subdev_state *state)
> +{
> +	struct v4l2_subdev_route routes[] = { {
> +		.sink_pad = 0,
> +		.sink_stream = 0,
> +		.source_pad = TI_CSI2RX_PAD_FIRST_SOURCE,
> +		.source_stream = 0,
> +		.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
> +	} };
> +
> +	struct v4l2_subdev_krouting routing = {
> +		.num_routes = 1,
> +		.routes = routes,
> +	};
> +
> +	/* Initialize routing to single route to the fist source pad */
> +	return _ti_csi2rx_sd_set_routing(sd, state, &routing);
>  }
>  
>  static int ti_csi2rx_sd_enable_streams(struct v4l2_subdev *sd,
> @@ -1065,14 +1188,18 @@ static int ti_csi2rx_sd_enable_streams(struct v4l2_subdev *sd,
>  {
>  	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
>  	struct media_pad *remote_pad;
> +	u64 sink_streams;
>  	int ret = 0;
>  
>  	remote_pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
>  	if (!remote_pad)
>  		return -ENODEV;
> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
> +						       TI_CSI2RX_PAD_SINK,
> +						       &streams_mask);
>  
>  	ret = v4l2_subdev_enable_streams(csi->source, remote_pad->index,
> -					 BIT(0));
> +					 sink_streams);
>  	if (ret)
>  		return ret;
>  
> @@ -1087,17 +1214,21 @@ static int ti_csi2rx_sd_disable_streams(struct v4l2_subdev *sd,
>  {
>  	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
>  	struct media_pad *remote_pad;
> +	u64 sink_streams;
>  	int ret = 0;
>  
>  	remote_pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
>  	if (!remote_pad)
>  		return -ENODEV;
> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
> +						       TI_CSI2RX_PAD_SINK,
> +						       &streams_mask);
>  
>  	if (csi->enable_count == 0)
>  		return -EINVAL;
>  
>  	ret = v4l2_subdev_disable_streams(csi->source, remote_pad->index,
> -					  BIT(0));
> +					  sink_streams);
>  	if (!ret)
>  		--csi->enable_count;
>  
> @@ -1106,6 +1237,7 @@ static int ti_csi2rx_sd_disable_streams(struct v4l2_subdev *sd,
>  
>  static const struct v4l2_subdev_pad_ops ti_csi2rx_subdev_pad_ops = {
>  	.enum_mbus_code	= ti_csi2rx_enum_mbus_code,
> +	.set_routing = ti_csi2rx_sd_set_routing,
>  	.get_fmt = v4l2_subdev_get_fmt,
>  	.set_fmt = ti_csi2rx_sd_set_fmt,
>  	.enable_streams = ti_csi2rx_sd_enable_streams,
> @@ -1284,7 +1416,7 @@ static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
>  	v4l2_subdev_init(sd, &ti_csi2rx_subdev_ops);
>  	sd->internal_ops = &ti_csi2rx_internal_ops;
>  	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> -	sd->flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	sd->flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_STREAMS;
>  	strscpy(sd->name, dev_name(csi->dev), sizeof(sd->name));
>  	sd->dev = csi->dev;
>  	sd->entity.ops = &ti_csi2rx_subdev_entity_ops;
> @@ -1347,6 +1479,8 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
>  
>  	ti_csi2rx_fill_fmt(fmt, &ctx->v_fmt);
>  
> +	ctx->route = NULL;
> +
>  	ctx->pad.flags = MEDIA_PAD_FL_SINK;
>  	vdev->entity.ops = &ti_csi2rx_video_entity_ops;
>  	ret = media_entity_pads_init(&ctx->vdev.entity, 1, &ctx->pad);

Re: [PATCH v8 16/18] media: cadence: csi2rx: Support runtime PM

[Tomi Valkeinen]

Hi,

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> From: Changhuang Liang <changhuang.liang@starfivetech.com>
> 
> Use runtime power management hooks to save power when CSI-RX is not in
> use.
> 
> Signed-off-by: Changhuang Liang <changhuang.liang@starfivetech.com>
> Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  drivers/media/platform/cadence/Kconfig       |   1 +
>  drivers/media/platform/cadence/cdns-csi2rx.c | 129 ++++++++++++-------
>  2 files changed, 83 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/media/platform/cadence/Kconfig b/drivers/media/platform/cadence/Kconfig
> index 1aa608c00dbce..ea85ef82760e6 100644
> --- a/drivers/media/platform/cadence/Kconfig
> +++ b/drivers/media/platform/cadence/Kconfig
> @@ -5,6 +5,7 @@ comment "Cadence media platform drivers"
>  config VIDEO_CADENCE_CSI2RX
>  	tristate "Cadence MIPI-CSI2 RX Controller"
>  	depends on VIDEO_DEV
> +	depends on PM
>  	select MEDIA_CONTROLLER
>  	select VIDEO_V4L2_SUBDEV_API
>  	select V4L2_FWNODE
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 833bc134f17cb..6447c225ba354 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -337,11 +337,6 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  	u32 reg;
>  	int ret;
>  
> -	ret = clk_prepare_enable(csi2rx->p_clk);
> -	if (ret)
> -		return ret;
> -
> -	reset_control_deassert(csi2rx->p_rst);
>  	csi2rx_reset(csi2rx);
>  
>  	if (csi2rx->error_irq >= 0)
> @@ -382,7 +377,7 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  		if (ret) {
>  			dev_err(csi2rx->dev,
>  				"Failed to configure external DPHY: %d\n", ret);
> -			goto err_disable_pclk;
> +			return ret;
>  		}
>  	}
>  
> @@ -397,12 +392,6 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  	 * hence the reference counting.
>  	 */
>  	for (i = 0; i < csi2rx->max_streams; i++) {
> -		ret = clk_prepare_enable(csi2rx->pixel_clk[i]);
> -		if (ret)
> -			goto err_disable_pixclk;
> -
> -		reset_control_deassert(csi2rx->pixel_rst[i]);
> -
>  		writel(CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF |
>  			       FIELD_PREP(CSI2RX_STREAM_CFG_NUM_PIXELS_MASK,
>  					  csi2rx->num_pixels[i]),
> @@ -415,30 +404,8 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  		       csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
>  	}
>  
> -	ret = clk_prepare_enable(csi2rx->sys_clk);
> -	if (ret)
> -		goto err_disable_pixclk;
> -
> -	reset_control_deassert(csi2rx->sys_rst);
> -
> -	clk_disable_unprepare(csi2rx->p_clk);
>  
>  	return 0;
> -
> -err_disable_pixclk:
> -	for (; i > 0; i--) {
> -		reset_control_assert(csi2rx->pixel_rst[i - 1]);
> -		clk_disable_unprepare(csi2rx->pixel_clk[i - 1]);
> -	}
> -
> -	if (csi2rx->dphy) {
> -		writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
> -		phy_power_off(csi2rx->dphy);
> -	}
> -err_disable_pclk:
> -	clk_disable_unprepare(csi2rx->p_clk);
> -
> -	return ret;
>  }
>  
>  static void csi2rx_stop(struct csi2rx_priv *csi2rx)
> @@ -447,10 +414,6 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
>  	u32 val;
>  	int ret;
>  
> -	clk_prepare_enable(csi2rx->p_clk);
> -	reset_control_assert(csi2rx->sys_rst);
> -	clk_disable_unprepare(csi2rx->sys_clk);
> -
>  	writel(0, csi2rx->base + CSI2RX_ERROR_IRQS_MASK_REG);
>  
>  	for (i = 0; i < csi2rx->max_streams; i++) {
> @@ -465,14 +428,8 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
>  		if (ret)
>  			dev_warn(csi2rx->dev,
>  				 "Failed to stop streaming on pad%u\n", i);
> -
> -		reset_control_assert(csi2rx->pixel_rst[i]);
> -		clk_disable_unprepare(csi2rx->pixel_clk[i]);
>  	}
>  
> -	reset_control_assert(csi2rx->p_rst);
> -	clk_disable_unprepare(csi2rx->p_clk);
> -
>  	if (csi2rx->dphy) {
>  		writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
>  
> @@ -548,10 +505,17 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>  	 * enable the whole controller.
>  	 */
>  	if (!csi2rx->count) {
> +		ret = pm_runtime_resume_and_get(csi2rx->dev);
> +		if (ret < 0)
> +			return ret;
> +
>  		csi2rx_update_vc_select(csi2rx, state);
> +
>  		ret = csi2rx_start(csi2rx);
> -		if (ret)
> +		if (ret) {
> +			pm_runtime_put(csi2rx->dev);
>  			return ret;
> +		}
>  	}
>  
>  	/* Start streaming on the source */
> @@ -561,8 +525,10 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>  		dev_err(csi2rx->dev,
>  			"Failed to start streams %#llx on subdev\n",
>  			sink_streams);
> -		if (!csi2rx->count)
> +		if (!csi2rx->count) {
>  			csi2rx_stop(csi2rx);
> +			pm_runtime_put(csi2rx->dev);

Probably time to add 'goto' based error handling to this func... Maybe
in this patch, maybe as a separate patch before this.

 Tomi

> +		}
>  		return ret;
>  	}
>  
> @@ -589,8 +555,10 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>  	csi2rx->count--;
>  
>  	/* Let the last user turn off the lights. */
> -	if (!csi2rx->count)
> +	if (!csi2rx->count) {
>  		csi2rx_stop(csi2rx);
> +		pm_runtime_put(csi2rx->dev);
> +	}
>  
>  	return 0;
>  }
> @@ -1092,6 +1060,7 @@ static int csi2rx_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto err_cleanup;
>  
> +	pm_runtime_enable(csi2rx->dev);
>  	ret = v4l2_async_register_subdev(&csi2rx->subdev);
>  	if (ret < 0)
>  		goto err_free_state;
> @@ -1106,6 +1075,7 @@ static int csi2rx_probe(struct platform_device *pdev)
>  
>  err_free_state:
>  	v4l2_subdev_cleanup(&csi2rx->subdev);
> +	pm_runtime_disable(csi2rx->dev);
>  err_cleanup:
>  	v4l2_async_nf_unregister(&csi2rx->notifier);
>  	v4l2_async_nf_cleanup(&csi2rx->notifier);
> @@ -1124,9 +1094,73 @@ static void csi2rx_remove(struct platform_device *pdev)
>  	v4l2_async_unregister_subdev(&csi2rx->subdev);
>  	v4l2_subdev_cleanup(&csi2rx->subdev);
>  	media_entity_cleanup(&csi2rx->subdev.entity);
> +	pm_runtime_disable(csi2rx->dev);
>  	kfree(csi2rx);
>  }
>  
> +static int csi2rx_runtime_suspend(struct device *dev)
> +{
> +	struct csi2rx_priv *csi2rx = dev_get_drvdata(dev);
> +	unsigned int i;
> +
> +	reset_control_assert(csi2rx->sys_rst);
> +	clk_disable_unprepare(csi2rx->sys_clk);
> +
> +	for (i = 0; i < csi2rx->max_streams; i++) {
> +		reset_control_assert(csi2rx->pixel_rst[i]);
> +		clk_disable_unprepare(csi2rx->pixel_clk[i]);
> +	}
> +
> +	reset_control_assert(csi2rx->p_rst);
> +	clk_disable_unprepare(csi2rx->p_clk);
> +
> +	return 0;
> +}
> +
> +static int csi2rx_runtime_resume(struct device *dev)
> +{
> +	struct csi2rx_priv *csi2rx = dev_get_drvdata(dev);
> +	unsigned int i;
> +	int ret;
> +
> +	ret = clk_prepare_enable(csi2rx->p_clk);
> +	if (ret)
> +		return ret;
> +
> +	reset_control_deassert(csi2rx->p_rst);
> +
> +	for (i = 0; i < csi2rx->max_streams; i++) {
> +		ret = clk_prepare_enable(csi2rx->pixel_clk[i]);
> +		if (ret)
> +			goto err_disable_pixclk;
> +
> +		reset_control_deassert(csi2rx->pixel_rst[i]);
> +	}
> +
> +	ret = clk_prepare_enable(csi2rx->sys_clk);
> +	if (ret)
> +		goto err_disable_pixclk;
> +
> +	reset_control_deassert(csi2rx->sys_rst);
> +
> +	return 0;
> +
> +err_disable_pixclk:
> +	for (; i > 0; i--) {
> +		reset_control_assert(csi2rx->pixel_rst[i - 1]);
> +		clk_disable_unprepare(csi2rx->pixel_clk[i - 1]);
> +	}
> +
> +	reset_control_assert(csi2rx->p_rst);
> +	clk_disable_unprepare(csi2rx->p_clk);
> +
> +	return ret;
> +}
> +
> +static const struct dev_pm_ops csi2rx_pm_ops = {
> +	RUNTIME_PM_OPS(csi2rx_runtime_suspend, csi2rx_runtime_resume, NULL)
> +};
> +
>  static const struct of_device_id csi2rx_of_table[] = {
>  	{ .compatible = "starfive,jh7110-csi2rx" },
>  	{ .compatible = "cdns,csi2rx" },
> @@ -1141,6 +1175,7 @@ static struct platform_driver csi2rx_driver = {
>  	.driver	= {
>  		.name		= "cdns-csi2rx",
>  		.of_match_table	= csi2rx_of_table,
> +		.pm		= &csi2rx_pm_ops,
>  	},
>  };
>  module_platform_driver(csi2rx_driver);

Re: [PATCH v8 17/18] media: ti: j721e-csi2rx: Support runtime suspend

[Tomi Valkeinen]

Hi,

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> From: Jai Luthra <jai.luthra@ideasonboard.com>
> 
> Add support for runtime power-management to enable powering off the
> shared power domain between Cadence CSI2RX and TI CSI2RX wrapper when
> the device(s) are not in use.
> 
> When powering off the IP, the PSI-L endpoint loses the paired DMA
> channels. Thus we have to release the DMA channels at runtime suspend
> and request them again at resume.

I'm not an expert on the dmaengine, but to me this sounds like a bug in
the dma driver. It just sounds very wrong...

> Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  drivers/media/platform/ti/Kconfig             |  1 +
>  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 55 ++++++++++++++++++-
>  2 files changed, 54 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
> index 3bc4aa35887e6..a808063e24779 100644
> --- a/drivers/media/platform/ti/Kconfig
> +++ b/drivers/media/platform/ti/Kconfig
> @@ -70,6 +70,7 @@ config VIDEO_TI_J721E_CSI2RX
>  	depends on VIDEO_CADENCE_CSI2RX
>  	depends on PHY_CADENCE_DPHY_RX || COMPILE_TEST
>  	depends on ARCH_K3 || COMPILE_TEST
> +	depends on PM
>  	select VIDEOBUF2_DMA_CONTIG
>  	select V4L2_FWNODE
>  	help
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> index 528041ee78cf3..21e032c64b901 100644
> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> @@ -13,6 +13,7 @@
>  #include <linux/module.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/property.h>
>  
>  #include <media/cadence/cdns-csi2rx.h>
> @@ -963,12 +964,16 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	unsigned long flags;
>  	int ret = 0;
>  
> +	ret = pm_runtime_resume_and_get(csi->dev);
> +	if (ret)
> +		return ret;
> +
>  	spin_lock_irqsave(&dma->lock, flags);
>  	if (list_empty(&dma->queue))
>  		ret = -EIO;
>  	spin_unlock_irqrestore(&dma->lock, flags);
>  	if (ret)
> -		return ret;
> +		goto err;
>  
>  	ret = video_device_pipeline_start(&ctx->vdev, &csi->pipe);
>  	if (ret)
> @@ -1024,6 +1029,8 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
>  err:
>  	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
> +	pm_runtime_put(csi->dev);
> +
>  	return ret;
>  }
>  
> @@ -1055,6 +1062,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
>  
>  	ti_csi2rx_stop_dma(ctx);
>  	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
> +	pm_runtime_put(csi->dev);
>  }
>  
>  static const struct vb2_ops csi_vb2_qops = {
> @@ -1261,7 +1269,9 @@ static void ti_csi2rx_cleanup_notifier(struct ti_csi2rx_dev *csi)
>  
>  static void ti_csi2rx_cleanup_ctx(struct ti_csi2rx_ctx *ctx)
>  {
> -	dma_release_channel(ctx->dma.chan);
> +	if (!pm_runtime_status_suspended(ctx->csi->dev))
> +		dma_release_channel(ctx->dma.chan);
> +
>  	vb2_queue_release(&ctx->vidq);
>  
>  	video_unregister_device(&ctx->vdev);
> @@ -1512,6 +1522,39 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
>  	return ret;
>  }
>  
> +static int ti_csi2rx_runtime_suspend(struct device *dev)
> +{
> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> +	int i;
> +
> +	if (csi->enable_count != 0)
> +		return -EBUSY;
> +
> +	for (i = 0; i < csi->num_ctx; i++)
> +		dma_release_channel(csi->ctx[i].dma.chan);
> +
> +	return 0;
> +}
> +
> +static int ti_csi2rx_runtime_resume(struct device *dev)
> +{
> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> +	int ret, i;
> +
> +	for (i = 0; i < csi->num_ctx; i++) {
> +		ret = ti_csi2rx_init_dma(&csi->ctx[i]);

If runtime_resume always requests the dma channels, is the call to
ti_csi2rx_init_dma() in ti_csi2rx_init_ctx() needed? If not, you could
inline the code from ti_csi2rx_init_dma() to here and also drop the
dma_release_channel() call from ti_csi2rx_cleanup_ctx(), making the flow
more understandable.

> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops ti_csi2rx_pm_ops = {
> +	RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
> +		       NULL)
> +};
> +
>  static int ti_csi2rx_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np = pdev->dev.of_node;
> @@ -1579,6 +1622,10 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
>  		goto err_notifier;
>  	}
>  
> +	pm_runtime_set_active(csi->dev);
> +	pm_runtime_enable(csi->dev);
> +	pm_request_idle(csi->dev);

I always forget what exactly the runtime_pm funcs do. What's the idea
here? If you do something else than the plain standard
pm_runtime_enable(), I think it's good to mention what/why in a comment.

>  	return 0;
>  
>  err_notifier:
> @@ -1609,6 +1656,9 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
>  	mutex_destroy(&csi->mutex);
>  	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
>  			  csi->drain.paddr);
> +	pm_runtime_disable(&pdev->dev);
> +	pm_runtime_set_suspended(&pdev->dev);
> +
>  }
>  
>  static const struct of_device_id ti_csi2rx_of_match[] = {
> @@ -1623,6 +1673,7 @@ static struct platform_driver ti_csi2rx_pdrv = {
>  	.driver = {
>  		.name = TI_CSI2RX_MODULE_NAME,
>  		.of_match_table = ti_csi2rx_of_match,
> +		.pm		= &ti_csi2rx_pm_ops,
>  	},
>  };
>  

Re: [PATCH v8 18/18] media: ti: j721e-csi2rx: Support system suspend using pm_notifier

[Tomi Valkeinen]

Hi,

On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> From: Jai Luthra <jai.luthra@ideasonboard.com>
> 
> As this device is the "orchestrator" for the rest of the media
> pipeline, we need to stop all on-going streams before system suspend and
> enable them back when the system wakes up from sleep.
> 
> Using .suspend/.resume callbacks does not work, as the order of those
> callbacks amongst various devices in the camera pipeline like the sensor,
> FPD serdes, CSI bridge etc. is impossible to enforce, even with
> device links. For example, the Cadence CSI bridge is a child device of
> this device, thus we cannot create a device link with the CSI bridge as
> a provider and this device as consumer. This can lead to situations
> where all the dependencies for the bridge have not yet resumed when we
> request the subdev to start streaming again through the .resume callback
> defined in this device.
> 
> Instead here we register a notifier callback with the PM framework
> which is triggered when the system is fully functional. At this point we
> can cleanly stop or start the streams, because we know all other devices
> and their dependencies are functional. A downside of this approach is
> that the userspace is also alive (not frozen yet, or just thawed), so
> the suspend notifier might complete before the userspace has completed
> all ioctls, like QBUF/DQBUF/STREAMON/STREAMOFF.
> 
> Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> ---
>  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 128 ++++++++++++++++++
>  1 file changed, 128 insertions(+)
> 
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> index 21e032c64b901..dd47758d51a90 100644
> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> @@ -131,6 +131,7 @@ struct ti_csi2rx_dev {
>  	struct v4l2_subdev		*source;
>  	struct v4l2_subdev		subdev;
>  	struct ti_csi2rx_ctx		ctx[TI_CSI2RX_MAX_CTX];
> +	struct notifier_block		pm_notifier;
>  	u8				pix_per_clk;
>  	/* Buffer to drain stale data from PSI-L endpoint */
>  	struct {
> @@ -1550,6 +1551,124 @@ static int ti_csi2rx_runtime_resume(struct device *dev)
>  	return 0;
>  }
>  
> +static int ti_csi2rx_suspend(struct device *dev)
> +{
> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> +	enum ti_csi2rx_dma_state state;
> +	struct ti_csi2rx_ctx *ctx;
> +	struct ti_csi2rx_dma *dma;
> +	unsigned long flags = 0;
> +	int i, ret = 0;
> +
> +	/* If device was not in use we can simply suspend */
> +	if (pm_runtime_status_suspended(dev))
> +		return 0;
> +
> +	/*
> +	 * If device is running, assert the pixel reset to cleanly stop any
> +	 * on-going streams before we suspend.
> +	 */
> +	writel(0, csi->shim + SHIM_CNTL);
> +
> +	for (i = 0; i < csi->num_ctx; i++) {
> +		ctx = &csi->ctx[i];
> +		dma = &ctx->dma;
> +
> +		spin_lock_irqsave(&dma->lock, flags);
> +		state = dma->state;
> +		spin_unlock_irqrestore(&dma->lock, flags);
> +
> +		if (state != TI_CSI2RX_DMA_STOPPED) {
> +			/* Disable source */
> +			ret = v4l2_subdev_disable_streams(&csi->subdev,
> +							  TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
> +							  BIT(0));
> +			if (ret)
> +				dev_err(csi->dev, "Failed to stop subdev stream\n");
> +		}
> +
> +		/* Stop any on-going streams */
> +		writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
> +
> +		/* Drain DMA */
> +		ti_csi2rx_drain_dma(ctx);
> +
> +		/* Terminate DMA */
> +		ret = dmaengine_terminate_sync(ctx->dma.chan);
> +		if (ret)
> +			dev_err(csi->dev, "Failed to stop DMA\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int ti_csi2rx_resume(struct device *dev)
> +{
> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> +	struct ti_csi2rx_ctx *ctx;
> +	struct ti_csi2rx_dma *dma;
> +	struct ti_csi2rx_buffer *buf;
> +	unsigned long flags = 0;
> +	unsigned int reg;
> +	int i, ret = 0;
> +
> +	/* If device was not in use, we can simply wakeup */
> +	if (pm_runtime_status_suspended(dev))
> +		return 0;

Don't we have a streaming-count that would be more intuitive to use as a
"are we streaming"?

And the previous patch said that we lose the DMA channel pairings when
suspending. Doesn't that happen here?

 Tomi

> +
> +	/* If device was in use before, restore all the running streams */
> +	reg = SHIM_CNTL_PIX_RST;
> +	writel(reg, csi->shim + SHIM_CNTL);
> +
> +	for (i = 0; i < csi->num_ctx; i++) {
> +		ctx = &csi->ctx[i];
> +		dma = &ctx->dma;
> +		spin_lock_irqsave(&dma->lock, flags);
> +		if (dma->state != TI_CSI2RX_DMA_STOPPED) {
> +			/* Re-submit all previously submitted buffers to DMA */
> +			list_for_each_entry(buf, &ctx->dma.submitted, list) {
> +				ti_csi2rx_start_dma(ctx, buf);
> +			}
> +			spin_unlock_irqrestore(&dma->lock, flags);
> +
> +			/* Restore stream config */
> +			ti_csi2rx_setup_shim(ctx);
> +
> +			ret = v4l2_subdev_enable_streams(&csi->subdev,
> +							 TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
> +							 BIT(0));
> +			if (ret)
> +				dev_err(ctx->csi->dev, "Failed to start subdev\n");
> +		} else {
> +			spin_unlock_irqrestore(&dma->lock, flags);
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static int ti_csi2rx_pm_notifier(struct notifier_block *nb,
> +				 unsigned long action, void *data)
> +{
> +	struct ti_csi2rx_dev *csi =
> +		container_of(nb, struct ti_csi2rx_dev, pm_notifier);
> +
> +	switch (action) {
> +	case PM_HIBERNATION_PREPARE:
> +	case PM_SUSPEND_PREPARE:
> +	case PM_RESTORE_PREPARE:
> +		ti_csi2rx_suspend(csi->dev);
> +		break;
> +	case PM_POST_SUSPEND:
> +	case PM_POST_HIBERNATION:
> +	case PM_POST_RESTORE:
> +		ti_csi2rx_resume(csi->dev);
> +		break;
> +	}
> +
> +	return NOTIFY_DONE;
> +}
> +
>  static const struct dev_pm_ops ti_csi2rx_pm_ops = {
>  	RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
>  		       NULL)
> @@ -1622,6 +1741,13 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
>  		goto err_notifier;
>  	}
>  
> +	csi->pm_notifier.notifier_call = ti_csi2rx_pm_notifier;
> +	ret = register_pm_notifier(&csi->pm_notifier);
> +	if (ret) {
> +		dev_err(csi->dev, "Failed to create PM notifier: %d\n", ret);
> +		goto err_notifier;
> +	}
> +
>  	pm_runtime_set_active(csi->dev);
>  	pm_runtime_enable(csi->dev);
>  	pm_request_idle(csi->dev);
> @@ -1652,6 +1778,8 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
>  		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
>  
>  	ti_csi2rx_cleanup_notifier(csi);
> +	unregister_pm_notifier(&csi->pm_notifier);
> +
>  	ti_csi2rx_cleanup_v4l2(csi);
>  	mutex_destroy(&csi->mutex);
>  	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,

Re: [PATCH v8 10/18] media: cadence: csi2rx: add get_frame_desc wrapper

[Rishikesh Donadkar]

On 20/11/25 18:10, Tomi Valkeinen wrote:
>
> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
>> From: Pratyush Yadav <p.yadav@ti.com>
>>
>> J721E wrapper CSI2RX driver needs to get the frame descriptor from the
>> source to find out info about virtual channel. This driver itself does
>> not touch the routing or virtual channels in any way. So simply pass the
>> descriptor through from the source.


Hi Tomi,

> Unfortunately I think that doesn't work.
>
> E.g. we have a fpdllink deser and the cdns csi2rx.
>
> Deser's routing table (pad/stream):
>
> 0/0 -> 4/15
> 0/1 -> 4/33
>
> So we have two streams coming into the deser's pad 0, with stream IDs 0
> and 1. They are routed by the user to output pad 4, with stream IDs 15
> and 33.
>
> cdns csi2rx routing table:
>
> 0/15 -> 1/0
> 0/33 -> 1/1
>
> So cdns csi2rx routes the streams through, as stream IDs 0 and 1 on the
> output side.
>
> With this patch, if the j2 csi2rx asks frame desc from cdns csi2rx, it
> gets a frame desc with two streams, stream IDs 15 and 33.


Thank you for pointing out, I will change the body of get_frame_desc() 
in this subdev driver set the stream field of the fd to the sink_stream 
of the corresponding route.


Rishikesh

>
> I made this series for the issue above, but it hasn't been merged:
>
> https://lore.kernel.org/all/20250324-frame-desc-passthrough-v4-0-dbe2412297cc%40ideasonboard.com/
>
>   Tomi
>
>> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
>> Signed-off-by: Jai Luthra <j-luthra@ti.com>
>> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
>> Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
>> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> ---
>>   drivers/media/platform/cadence/cdns-csi2rx.c | 24 ++++++++++++++++++++
>>   1 file changed, 24 insertions(+)
>>
>> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
>> index 34da81893308b..3688077fa8347 100644
>> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
>> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
>> @@ -229,6 +229,21 @@ static const struct csi2rx_fmt *csi2rx_get_fmt_by_code(u32 code)
>>   	return NULL;
>>   }
>>   
>> +static int csi2rx_get_frame_desc_from_source(struct csi2rx_priv *csi2rx,
>> +					     struct v4l2_mbus_frame_desc *fd)
>> +{
>> +	struct media_pad *remote_pad;
>> +
>> +	remote_pad = media_entity_remote_source_pad_unique(&csi2rx->subdev.entity);
>> +	if (!remote_pad) {
>> +		dev_err(csi2rx->dev, "No remote pad found for sink\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	return v4l2_subdev_call(csi2rx->source_subdev, pad, get_frame_desc,
>> +				remote_pad->index, fd);
>> +}
>> +
>>   static inline
>>   struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)
>>   {
>> @@ -611,12 +626,21 @@ int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
>>   }
>>   EXPORT_SYMBOL_FOR_MODULES(cdns_csi2rx_negotiate_ppc, "j721e-csi2rx");
>>   
>> +static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
>> +				 struct v4l2_mbus_frame_desc *fd)
>> +{
>> +	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +
>> +	return csi2rx_get_frame_desc_from_source(csi2rx, fd);
>> +}
>> +
>>   static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
>>   	.enum_mbus_code	= csi2rx_enum_mbus_code,
>>   	.get_fmt	= v4l2_subdev_get_fmt,
>>   	.set_fmt	= csi2rx_set_fmt,
>>   	.enable_streams         = csi2rx_enable_streams,
>>   	.disable_streams        = csi2rx_disable_streams,
>> +	.get_frame_desc	= csi2rx_get_frame_desc,
>>   };
>>   
>>   static const struct v4l2_subdev_core_ops csi2rx_core_ops = {

Re: [PATCH v8 17/18] media: ti: j721e-csi2rx: Support runtime suspend

[Jai Luthra]

Hi Tomi,

Quoting Tomi Valkeinen (2025-12-01 18:52:36)
> Hi,
> 
> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> > From: Jai Luthra <jai.luthra@ideasonboard.com>
> > 
> > Add support for runtime power-management to enable powering off the
> > shared power domain between Cadence CSI2RX and TI CSI2RX wrapper when
> > the device(s) are not in use.
> > 
> > When powering off the IP, the PSI-L endpoint loses the paired DMA
> > channels. Thus we have to release the DMA channels at runtime suspend
> > and request them again at resume.
> 
> I'm not an expert on the dmaengine, but to me this sounds like a bug in
> the dma driver. It just sounds very wrong...
> 

Cc: Vignesh

IIRC this was done because on AM62 the CSI2RX is on a separate power domain
and it uses DMA channels from the system-wide DMA engine.

And as those two drivers have different set of users, we have situations
where CSI2RX goes to runtime suspend state and turns off the power and
clocks, while the DMA engine remains on as it has other users. This leads
to the paired PSIL channels to become invalid, and needs a re-pairing.

I am not an expert on DMA engine APIs to know how feasible it would be to
do the book-keeping of the power state of various devices in the DMA driver
and manage the re-pairing entirely there.

On AM62A and later devices, there is a dedicated instance of the BCDMA
engine for camera pipeline on the same power domain as CSI2RX, so this is
not a problem. Rishikesh/Vignesh please correct me if I'm wrong, as it has
been a while since I looked at this in depth.


> > Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
> > Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > ---
> >  drivers/media/platform/ti/Kconfig             |  1 +
> >  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 55 ++++++++++++++++++-
> >  2 files changed, 54 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
> > index 3bc4aa35887e6..a808063e24779 100644
> > --- a/drivers/media/platform/ti/Kconfig
> > +++ b/drivers/media/platform/ti/Kconfig
> > @@ -70,6 +70,7 @@ config VIDEO_TI_J721E_CSI2RX
> >       depends on VIDEO_CADENCE_CSI2RX
> >       depends on PHY_CADENCE_DPHY_RX || COMPILE_TEST
> >       depends on ARCH_K3 || COMPILE_TEST
> > +     depends on PM
> >       select VIDEOBUF2_DMA_CONTIG
> >       select V4L2_FWNODE
> >       help
> > diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > index 528041ee78cf3..21e032c64b901 100644
> > --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > @@ -13,6 +13,7 @@
> >  #include <linux/module.h>
> >  #include <linux/of_platform.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> >  #include <linux/property.h>
> >  
> >  #include <media/cadence/cdns-csi2rx.h>
> > @@ -963,12 +964,16 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> >       unsigned long flags;
> >       int ret = 0;
> >  
> > +     ret = pm_runtime_resume_and_get(csi->dev);
> > +     if (ret)
> > +             return ret;
> > +
> >       spin_lock_irqsave(&dma->lock, flags);
> >       if (list_empty(&dma->queue))
> >               ret = -EIO;
> >       spin_unlock_irqrestore(&dma->lock, flags);
> >       if (ret)
> > -             return ret;
> > +             goto err;
> >  
> >       ret = video_device_pipeline_start(&ctx->vdev, &csi->pipe);
> >       if (ret)
> > @@ -1024,6 +1029,8 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> >       writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
> >  err:
> >       ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
> > +     pm_runtime_put(csi->dev);
> > +
> >       return ret;
> >  }
> >  
> > @@ -1055,6 +1062,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
> >  
> >       ti_csi2rx_stop_dma(ctx);
> >       ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
> > +     pm_runtime_put(csi->dev);
> >  }
> >  
> >  static const struct vb2_ops csi_vb2_qops = {
> > @@ -1261,7 +1269,9 @@ static void ti_csi2rx_cleanup_notifier(struct ti_csi2rx_dev *csi)
> >  
> >  static void ti_csi2rx_cleanup_ctx(struct ti_csi2rx_ctx *ctx)
> >  {
> > -     dma_release_channel(ctx->dma.chan);
> > +     if (!pm_runtime_status_suspended(ctx->csi->dev))
> > +             dma_release_channel(ctx->dma.chan);
> > +
> >       vb2_queue_release(&ctx->vidq);
> >  
> >       video_unregister_device(&ctx->vdev);
> > @@ -1512,6 +1522,39 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
> >       return ret;
> >  }
> >  
> > +static int ti_csi2rx_runtime_suspend(struct device *dev)
> > +{
> > +     struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> > +     int i;
> > +
> > +     if (csi->enable_count != 0)
> > +             return -EBUSY;
> > +
> > +     for (i = 0; i < csi->num_ctx; i++)
> > +             dma_release_channel(csi->ctx[i].dma.chan);
> > +
> > +     return 0;
> > +}
> > +
> > +static int ti_csi2rx_runtime_resume(struct device *dev)
> > +{
> > +     struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> > +     int ret, i;
> > +
> > +     for (i = 0; i < csi->num_ctx; i++) {
> > +             ret = ti_csi2rx_init_dma(&csi->ctx[i]);
> 
> If runtime_resume always requests the dma channels, is the call to
> ti_csi2rx_init_dma() in ti_csi2rx_init_ctx() needed? If not, you could
> inline the code from ti_csi2rx_init_dma() to here and also drop the
> dma_release_channel() call from ti_csi2rx_cleanup_ctx(), making the flow
> more understandable.
> 

Makes sense.

> > +             if (ret)
> > +                     return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct dev_pm_ops ti_csi2rx_pm_ops = {
> > +     RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
> > +                    NULL)
> > +};
> > +
> >  static int ti_csi2rx_probe(struct platform_device *pdev)
> >  {
> >       struct device_node *np = pdev->dev.of_node;
> > @@ -1579,6 +1622,10 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
> >               goto err_notifier;
> >       }
> >  
> > +     pm_runtime_set_active(csi->dev);
> > +     pm_runtime_enable(csi->dev);
> > +     pm_request_idle(csi->dev);
> 
> I always forget what exactly the runtime_pm funcs do. What's the idea
> here? If you do something else than the plain standard
> pm_runtime_enable(), I think it's good to mention what/why in a comment.
> 

https://docs.kernel.org/power/runtime_pm.html#runtime-pm-initialization-device-probing-and-removal

The pm_request_idle() is done to queue up a job to suspend the hardware
until userspace starts streaming, to save power.

The runtime_set_active() is used because the power domain for CSI is by
default turned on when system boots up. But Rishikesh, please double check
that before v9 on AM62.

> >       return 0;
> >  
> >  err_notifier:
> > @@ -1609,6 +1656,9 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
> >       mutex_destroy(&csi->mutex);
> >       dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
> >                         csi->drain.paddr);
> > +     pm_runtime_disable(&pdev->dev);
> > +     pm_runtime_set_suspended(&pdev->dev);
> > +
> >  }
> >  
> >  static const struct of_device_id ti_csi2rx_of_match[] = {
> > @@ -1623,6 +1673,7 @@ static struct platform_driver ti_csi2rx_pdrv = {
> >       .driver = {
> >               .name = TI_CSI2RX_MODULE_NAME,
> >               .of_match_table = ti_csi2rx_of_match,
> > +             .pm             = &ti_csi2rx_pm_ops,
> >       },
> >  };
> >  
>

Re: [PATCH v8 17/18] media: ti: j721e-csi2rx: Support runtime suspend

[Jai Luthra]

Hi Sakari,

Thanks for the review.

Quoting Sakari Ailus (2025-11-20 18:46:14)
> Hi Rishikesh,
> 
> On Wed, Nov 12, 2025 at 05:24:58PM +0530, Rishikesh Donadkar wrote:
> > From: Jai Luthra <jai.luthra@ideasonboard.com>
> > 
> > Add support for runtime power-management to enable powering off the
> > shared power domain between Cadence CSI2RX and TI CSI2RX wrapper when
> > the device(s) are not in use.
> > 
> > When powering off the IP, the PSI-L endpoint loses the paired DMA
> > channels. Thus we have to release the DMA channels at runtime suspend
> > and request them again at resume.
> > 
> > Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
> > Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > ---
> >  drivers/media/platform/ti/Kconfig             |  1 +
> >  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 55 ++++++++++++++++++-
> >  2 files changed, 54 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
> > index 3bc4aa35887e6..a808063e24779 100644
> > --- a/drivers/media/platform/ti/Kconfig
> > +++ b/drivers/media/platform/ti/Kconfig
> > @@ -70,6 +70,7 @@ config VIDEO_TI_J721E_CSI2RX
> >       depends on VIDEO_CADENCE_CSI2RX
> >       depends on PHY_CADENCE_DPHY_RX || COMPILE_TEST
> >       depends on ARCH_K3 || COMPILE_TEST
> > +     depends on PM
> >       select VIDEOBUF2_DMA_CONTIG
> >       select V4L2_FWNODE
> >       help
> > diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > index 528041ee78cf3..21e032c64b901 100644
> > --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > @@ -13,6 +13,7 @@
> >  #include <linux/module.h>
> >  #include <linux/of_platform.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> >  #include <linux/property.h>
> >  
> >  #include <media/cadence/cdns-csi2rx.h>
> > @@ -963,12 +964,16 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> >       unsigned long flags;
> >       int ret = 0;
> >  
> > +     ret = pm_runtime_resume_and_get(csi->dev);
> > +     if (ret)
> > +             return ret;
> > +
> >       spin_lock_irqsave(&dma->lock, flags);
> >       if (list_empty(&dma->queue))
> >               ret = -EIO;
> >       spin_unlock_irqrestore(&dma->lock, flags);
> >       if (ret)
> > -             return ret;
> > +             goto err;
> >  
> >       ret = video_device_pipeline_start(&ctx->vdev, &csi->pipe);
> >       if (ret)
> > @@ -1024,6 +1029,8 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> >       writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
> >  err:
> >       ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
> > +     pm_runtime_put(csi->dev);
> > +
> >       return ret;
> >  }
> >  
> > @@ -1055,6 +1062,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
> >  
> >       ti_csi2rx_stop_dma(ctx);
> >       ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
> > +     pm_runtime_put(csi->dev);
> >  }
> >  
> >  static const struct vb2_ops csi_vb2_qops = {
> > @@ -1261,7 +1269,9 @@ static void ti_csi2rx_cleanup_notifier(struct ti_csi2rx_dev *csi)
> >  
> >  static void ti_csi2rx_cleanup_ctx(struct ti_csi2rx_ctx *ctx)
> >  {
> > -     dma_release_channel(ctx->dma.chan);
> > +     if (!pm_runtime_status_suspended(ctx->csi->dev))
> 
> What's the motivation for this change? Do the DMA channel need to be
> released only if the device's RPM status isn't suspended?
> 
> Is there a guarantee Runtime PM is disabled when the function is called?
> Otherwise there's no guarantee state change couldn't occur.
> 

The channels are released during PM runtime suspend, and re-paired in
resume. I like Tomi's suggestion of removing the channel logic from
init/cleanup_ctx altogether, which will also get rid of this change.

> > +             dma_release_channel(ctx->dma.chan);
> > +
> >       vb2_queue_release(&ctx->vidq);
> >  
> >       video_unregister_device(&ctx->vdev);
> > @@ -1512,6 +1522,39 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
> >       return ret;
> >  }
> >  
> > +static int ti_csi2rx_runtime_suspend(struct device *dev)
> > +{
> > +     struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> > +     int i;
> > +
> > +     if (csi->enable_count != 0)
> > +             return -EBUSY;
> > +
> > +     for (i = 0; i < csi->num_ctx; i++)
> > +             dma_release_channel(csi->ctx[i].dma.chan);
> > +
> > +     return 0;
> > +}
> > +
> > +static int ti_csi2rx_runtime_resume(struct device *dev)
> > +{
> > +     struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> > +     int ret, i;
> > +
> > +     for (i = 0; i < csi->num_ctx; i++) {
> 
> You could declare i (as unsigned int) here.
> 
> The same for ret actually.
> 

Will do.

> > +             ret = ti_csi2rx_init_dma(&csi->ctx[i]);
> > +             if (ret)
> > +                     return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct dev_pm_ops ti_csi2rx_pm_ops = {
> > +     RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
> > +                    NULL)
> > +};
> > +
> >  static int ti_csi2rx_probe(struct platform_device *pdev)
> >  {
> >       struct device_node *np = pdev->dev.of_node;
> > @@ -1579,6 +1622,10 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
> >               goto err_notifier;
> >       }
> >  
> > +     pm_runtime_set_active(csi->dev);
> > +     pm_runtime_enable(csi->dev);
> 
> Note that the sub-device driver's UAPI may be already available to users
> when the async sub-device is registered. Therefore you'll need enable
> runtime PM before that.
> 

The only place where the driver actually writes registers to the hardware
is in .start_streaming(), which I presume can only be called after the
whole media pipeline is probed?

> > +     pm_request_idle(csi->dev);
> > +
> >       return 0;
> >  
> >  err_notifier:
> > @@ -1609,6 +1656,9 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
> >       mutex_destroy(&csi->mutex);
> >       dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
> >                         csi->drain.paddr);
> 
> Is there a guarantee the device is in a particular runtime PM state here,
> e.g. suspended?
> 

I don't think so, userspace could attempt to remove the device while
streaming. Good point, I haven't checked what all goes wrong in that case.

> > +     pm_runtime_disable(&pdev->dev);
> > +     pm_runtime_set_suspended(&pdev->dev);
> > +
> >  }
> >  
> >  static const struct of_device_id ti_csi2rx_of_match[] = {
> > @@ -1623,6 +1673,7 @@ static struct platform_driver ti_csi2rx_pdrv = {
> >       .driver = {
> >               .name = TI_CSI2RX_MODULE_NAME,
> >               .of_match_table = ti_csi2rx_of_match,
> > +             .pm             = &ti_csi2rx_pm_ops,
> >       },
> >  };
> >  
> 
> -- 
> Kind regards,
> 
> Sakari Ailus

Thanks,
Jai

Re: [PATCH v8 18/18] media: ti: j721e-csi2rx: Support system suspend using pm_notifier

[Jai Luthra]

Quoting Tomi Valkeinen (2025-12-01 19:16:38)
> Hi,
> 
> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> > From: Jai Luthra <jai.luthra@ideasonboard.com>
> > 
> > As this device is the "orchestrator" for the rest of the media
> > pipeline, we need to stop all on-going streams before system suspend and
> > enable them back when the system wakes up from sleep.
> > 
> > Using .suspend/.resume callbacks does not work, as the order of those
> > callbacks amongst various devices in the camera pipeline like the sensor,
> > FPD serdes, CSI bridge etc. is impossible to enforce, even with
> > device links. For example, the Cadence CSI bridge is a child device of
> > this device, thus we cannot create a device link with the CSI bridge as
> > a provider and this device as consumer. This can lead to situations
> > where all the dependencies for the bridge have not yet resumed when we
> > request the subdev to start streaming again through the .resume callback
> > defined in this device.
> > 
> > Instead here we register a notifier callback with the PM framework
> > which is triggered when the system is fully functional. At this point we
> > can cleanly stop or start the streams, because we know all other devices
> > and their dependencies are functional. A downside of this approach is
> > that the userspace is also alive (not frozen yet, or just thawed), so
> > the suspend notifier might complete before the userspace has completed
> > all ioctls, like QBUF/DQBUF/STREAMON/STREAMOFF.
> > 
> > Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
> > Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> > ---
> >  .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 128 ++++++++++++++++++
> >  1 file changed, 128 insertions(+)
> > 
> > diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > index 21e032c64b901..dd47758d51a90 100644
> > --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > @@ -131,6 +131,7 @@ struct ti_csi2rx_dev {
> >       struct v4l2_subdev              *source;
> >       struct v4l2_subdev              subdev;
> >       struct ti_csi2rx_ctx            ctx[TI_CSI2RX_MAX_CTX];
> > +     struct notifier_block           pm_notifier;
> >       u8                              pix_per_clk;
> >       /* Buffer to drain stale data from PSI-L endpoint */
> >       struct {
> > @@ -1550,6 +1551,124 @@ static int ti_csi2rx_runtime_resume(struct device *dev)
> >       return 0;
> >  }
> >  
> > +static int ti_csi2rx_suspend(struct device *dev)
> > +{
> > +     struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> > +     enum ti_csi2rx_dma_state state;
> > +     struct ti_csi2rx_ctx *ctx;
> > +     struct ti_csi2rx_dma *dma;
> > +     unsigned long flags = 0;
> > +     int i, ret = 0;
> > +
> > +     /* If device was not in use we can simply suspend */
> > +     if (pm_runtime_status_suspended(dev))
> > +             return 0;
> > +
> > +     /*
> > +      * If device is running, assert the pixel reset to cleanly stop any
> > +      * on-going streams before we suspend.
> > +      */
> > +     writel(0, csi->shim + SHIM_CNTL);
> > +
> > +     for (i = 0; i < csi->num_ctx; i++) {
> > +             ctx = &csi->ctx[i];
> > +             dma = &ctx->dma;
> > +
> > +             spin_lock_irqsave(&dma->lock, flags);
> > +             state = dma->state;
> > +             spin_unlock_irqrestore(&dma->lock, flags);
> > +
> > +             if (state != TI_CSI2RX_DMA_STOPPED) {
> > +                     /* Disable source */
> > +                     ret = v4l2_subdev_disable_streams(&csi->subdev,
> > +                                                       TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
> > +                                                       BIT(0));
> > +                     if (ret)
> > +                             dev_err(csi->dev, "Failed to stop subdev stream\n");
> > +             }
> > +
> > +             /* Stop any on-going streams */
> > +             writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
> > +
> > +             /* Drain DMA */
> > +             ti_csi2rx_drain_dma(ctx);
> > +
> > +             /* Terminate DMA */
> > +             ret = dmaengine_terminate_sync(ctx->dma.chan);
> > +             if (ret)
> > +                     dev_err(csi->dev, "Failed to stop DMA\n");
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> > +static int ti_csi2rx_resume(struct device *dev)
> > +{
> > +     struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
> > +     struct ti_csi2rx_ctx *ctx;
> > +     struct ti_csi2rx_dma *dma;
> > +     struct ti_csi2rx_buffer *buf;
> > +     unsigned long flags = 0;
> > +     unsigned int reg;
> > +     int i, ret = 0;
> > +
> > +     /* If device was not in use, we can simply wakeup */
> > +     if (pm_runtime_status_suspended(dev))
> > +             return 0;
> 
> Don't we have a streaming-count that would be more intuitive to use as a
> "are we streaming"?

Indeed.

> 
> And the previous patch said that we lose the DMA channel pairings when
> suspending. Doesn't that happen here?

In the case of system suspend the UDMA driver has (late) hooks that do the
book-keeping of channel configuration and restores it (early) on system
resume.

Thanks,
    Jai
> 
>  Tomi
> 
> > +
> > +     /* If device was in use before, restore all the running streams */
> > +     reg = SHIM_CNTL_PIX_RST;
> > +     writel(reg, csi->shim + SHIM_CNTL);
> > +
> > +     for (i = 0; i < csi->num_ctx; i++) {
> > +             ctx = &csi->ctx[i];
> > +             dma = &ctx->dma;
> > +             spin_lock_irqsave(&dma->lock, flags);
> > +             if (dma->state != TI_CSI2RX_DMA_STOPPED) {
> > +                     /* Re-submit all previously submitted buffers to DMA */
> > +                     list_for_each_entry(buf, &ctx->dma.submitted, list) {
> > +                             ti_csi2rx_start_dma(ctx, buf);
> > +                     }
> > +                     spin_unlock_irqrestore(&dma->lock, flags);
> > +
> > +                     /* Restore stream config */
> > +                     ti_csi2rx_setup_shim(ctx);
> > +
> > +                     ret = v4l2_subdev_enable_streams(&csi->subdev,
> > +                                                      TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
> > +                                                      BIT(0));
> > +                     if (ret)
> > +                             dev_err(ctx->csi->dev, "Failed to start subdev\n");
> > +             } else {
> > +                     spin_unlock_irqrestore(&dma->lock, flags);
> > +             }
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> > +static int ti_csi2rx_pm_notifier(struct notifier_block *nb,
> > +                              unsigned long action, void *data)
> > +{
> > +     struct ti_csi2rx_dev *csi =
> > +             container_of(nb, struct ti_csi2rx_dev, pm_notifier);
> > +
> > +     switch (action) {
> > +     case PM_HIBERNATION_PREPARE:
> > +     case PM_SUSPEND_PREPARE:
> > +     case PM_RESTORE_PREPARE:
> > +             ti_csi2rx_suspend(csi->dev);
> > +             break;
> > +     case PM_POST_SUSPEND:
> > +     case PM_POST_HIBERNATION:
> > +     case PM_POST_RESTORE:
> > +             ti_csi2rx_resume(csi->dev);
> > +             break;
> > +     }
> > +
> > +     return NOTIFY_DONE;
> > +}
> > +
> >  static const struct dev_pm_ops ti_csi2rx_pm_ops = {
> >       RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
> >                      NULL)
> > @@ -1622,6 +1741,13 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
> >               goto err_notifier;
> >       }
> >  
> > +     csi->pm_notifier.notifier_call = ti_csi2rx_pm_notifier;
> > +     ret = register_pm_notifier(&csi->pm_notifier);
> > +     if (ret) {
> > +             dev_err(csi->dev, "Failed to create PM notifier: %d\n", ret);
> > +             goto err_notifier;
> > +     }
> > +
> >       pm_runtime_set_active(csi->dev);
> >       pm_runtime_enable(csi->dev);
> >       pm_request_idle(csi->dev);
> > @@ -1652,6 +1778,8 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
> >               ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
> >  
> >       ti_csi2rx_cleanup_notifier(csi);
> > +     unregister_pm_notifier(&csi->pm_notifier);
> > +
> >       ti_csi2rx_cleanup_v4l2(csi);
> >       mutex_destroy(&csi->mutex);
> >       dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
>

Re: [PATCH v8 17/18] media: ti: j721e-csi2rx: Support runtime suspend

[Sakari Ailus]

Hi Jai,

On Mon, Dec 08, 2025 at 01:17:21PM +0530, Jai Luthra wrote:
> > > @@ -1579,6 +1622,10 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
> > >               goto err_notifier;
> > >       }
> > >  
> > > +     pm_runtime_set_active(csi->dev);
> > > +     pm_runtime_enable(csi->dev);
> > 
> > Note that the sub-device driver's UAPI may be already available to users
> > when the async sub-device is registered. Therefore you'll need enable
> > runtime PM before that.
> > 
> 
> The only place where the driver actually writes registers to the hardware
> is in .start_streaming(), which I presume can only be called after the
> whole media pipeline is probed?

Correct, but without enabling runtime PM before registering the async
sub-device there's no guarantee of that order.

> 
> > > +     pm_request_idle(csi->dev);
> > > +
> > >       return 0;
> > >  
> > >  err_notifier:
> > > @@ -1609,6 +1656,9 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
> > >       mutex_destroy(&csi->mutex);
> > >       dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
> > >                         csi->drain.paddr);
> > 
> > Is there a guarantee the device is in a particular runtime PM state here,
> > e.g. suspended?
> > 
> 
> I don't think so, userspace could attempt to remove the device while
> streaming. Good point, I haven't checked what all goes wrong in that case.

We don't really support that yet. :-)

I'd still check the runtime Pm state and if it's active, I'd power the
device off.

> 
> > > +     pm_runtime_disable(&pdev->dev);
> > > +     pm_runtime_set_suspended(&pdev->dev);
> > > +
> > >  }
> > >  
> > >  static const struct of_device_id ti_csi2rx_of_match[] = {
> > > @@ -1623,6 +1673,7 @@ static struct platform_driver ti_csi2rx_pdrv = {
> > >       .driver = {
> > >               .name = TI_CSI2RX_MODULE_NAME,
> > >               .of_match_table = ti_csi2rx_of_match,
> > > +             .pm             = &ti_csi2rx_pm_ops,
> > >       },
> > >  };
> > >  
> > 

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v8 12/18] media: cadence: csi2rx: add multistream support

[Rishikesh Donadkar]

On 20/11/25 18:23, Sakari Ailus wrote:
> Hi Rishikesh,


Hi Sakari,

Thank you for the review !

>
> I'm not commenting on the use of {en,dis}able_streams in the series; it may
> be this area will need some work in general, including in V4L2 core.
>
> On Wed, Nov 12, 2025 at 05:24:53PM +0530, Rishikesh Donadkar wrote:
>> From: Jai Luthra <j-luthra@ti.com>
>>
>> Cadence CSI-2 bridge IP supports capturing multiple virtual "streams"
>> of data over the same physical interface using MIPI Virtual Channels.
>>
>> While the hardware IP supports usecases where streams coming in the sink
>> pad can be broadcasted to multiple source pads, the driver will need
>> significant re-architecture to make that possible. The two users of this
>> IP in mainline linux are TI Shim and StarFive JH7110 CAMSS, and both
>> have only integrated the first source pad i.e stream0 of this IP. So for
>> now keep it simple and only allow 1-to-1 mapping of streams from sink to
>> source, without any broadcasting.
>>
>> Implement a fallback s_stream hook that internally calls enable_stream
>> on each source pad, for consumer drivers that don't use multi-stream
>> APIs to still work. The helper function v4l2_subdev_s_stream_helper()
>> form the v4l2 framework is not used here as it is meant only for the
>> subedvs that have a single source pad and this hardware IP supports
>> having multiple source pads.
>>
>> Signed-off-by: Jai Luthra <j-luthra@ti.com>
>> Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
>> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
>> Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> ---
>>   drivers/media/platform/cadence/cdns-csi2rx.c | 283 ++++++++++++++++---
>>   1 file changed, 236 insertions(+), 47 deletions(-)
>>
>> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
>> index 3688077fa8347..833bc134f17cb 100644
>> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
>> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
>> @@ -135,6 +135,7 @@ struct csi2rx_priv {
>>   	struct phy			*dphy;
>>   
>>   	u8				num_pixels[CSI2RX_STREAMS_MAX];
>> +	u32				vc_select[CSI2RX_STREAMS_MAX];
>>   	u8				lanes[CSI2RX_LANES_MAX];
>>   	u8				num_lanes;
>>   	u8				max_lanes;
>> @@ -273,30 +274,43 @@ static void csi2rx_reset(struct csi2rx_priv *csi2rx)
>>   
>>   static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
>>   {
>> -	struct media_pad *src_pad =
>> -		&csi2rx->source_subdev->entity.pads[csi2rx->source_pad];
>>   	union phy_configure_opts opts = { };
>>   	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
>> -	struct v4l2_subdev_state *state;
>>   	struct v4l2_mbus_framefmt *framefmt;
>> +	struct v4l2_subdev_state *state;
>>   	const struct csi2rx_fmt *fmt;
>> +	int source_pad = csi2rx->source_pad;
>> +	struct media_pad *pad = &csi2rx->source_subdev->entity.pads[source_pad];
>>   	s64 link_freq;
>>   	int ret;
>> +	u32 bpp;
>>   
>>   	state = v4l2_subdev_get_locked_active_state(&csi2rx->subdev);
>>   
>> -	framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
>> -	if (!framefmt) {
>> -		dev_err(csi2rx->dev, "Did not find active sink format\n");
>> -		return -EINVAL;
>> -	}
>> +	/*
>> +	 * For multi-stream transmitters there is no single pixel rate.
>> +	 *
>> +	 * In multistream usecase pass bpp as 0 so that v4l2_get_link_freq()
>> +	 * returns an error if it falls back to V4L2_CID_PIXEL_RATE.
>> +	 */
>> +	if (state->routing.num_routes > 1) {
>> +		bpp = 0;
>> +	} else {
>> +		framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
>> +		if (!framefmt) {
>> +			dev_err(csi2rx->dev, "Did not find active sink format\n");
>> +			return -EINVAL;
>> +		}
>>   
>> -	fmt = csi2rx_get_fmt_by_code(framefmt->code);
>> +		fmt = csi2rx_get_fmt_by_code(framefmt->code);
>> +		bpp = fmt->bpp;
>> +	}
>>   
>> -	link_freq = v4l2_get_link_freq(src_pad,
>> -				       fmt->bpp, 2 * csi2rx->num_lanes);
>> -	if (link_freq < 0)
>> +	link_freq = v4l2_get_link_freq(pad, bpp, 2 * csi2rx->num_lanes);
>> +	if (link_freq < 0) {
>> +		dev_err(csi2rx->dev, "Unable to calculate link frequency\n");
>>   		return link_freq;
>> +	}
>>   
>>   	ret = phy_mipi_dphy_get_default_config_for_hsclk(link_freq,
>>   							 csi2rx->num_lanes, cfg);
>> @@ -394,11 +408,7 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>>   					  csi2rx->num_pixels[i]),
>>   		       csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
>>   
>> -		/*
>> -		 * Enable one virtual channel. When multiple virtual channels
>> -		 * are supported this will have to be changed.
>> -		 */
>> -		writel(CSI2RX_STREAM_DATA_CFG_VC_SELECT(0),
>> +		writel(csi2rx->vc_select[i],
>>   		       csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));
>>   
>>   		writel(CSI2RX_STREAM_CTRL_START,
>> @@ -486,18 +496,59 @@ static int csi2rx_log_status(struct v4l2_subdev *sd)
>>   	return 0;
>>   }
>>   
>> +static void csi2rx_update_vc_select(struct csi2rx_priv *csi2rx,
>> +				    struct v4l2_subdev_state *state)
>> +{
>> +	struct v4l2_mbus_frame_desc fd = {0};
>> +	struct v4l2_subdev_route *route;
>> +	unsigned int i;
>> +	int ret;
>> +
>> +	/* Capture VC=0 by default */
>> +	for (i = 0; i < CSI2RX_STREAMS_MAX; i++)
>> +		csi2rx->vc_select[i] = CSI2RX_STREAM_DATA_CFG_VC_SELECT(0);
>> +
>> +	ret = csi2rx_get_frame_desc_from_source(csi2rx, &fd);
>> +	if (ret || fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
>> +		dev_dbg(csi2rx->dev,
>> +			"Failed to get source frame desc, allowing only VC=0\n");
>> +		return;
>> +	}
>> +
>> +	/* If source provides per-stream VC info, use it to filter by VC */
>> +	memset(csi2rx->vc_select, 0, sizeof(csi2rx->vc_select));
>> +
>> +	for_each_active_route(&state->routing, route) {
>> +		u32 cdns_stream = route->source_pad - CSI2RX_PAD_SOURCE_STREAM0;
>> +
>> +		for (i = 0; i < fd.num_entries; i++) {
>> +			if (fd.entry[i].stream != route->sink_stream)
>> +				continue;
>> +
>> +			csi2rx->vc_select[cdns_stream] |=
>> +				CSI2RX_STREAM_DATA_CFG_VC_SELECT(fd.entry[i].bus.csi2.vc);
>> +		}
>> +	}
>> +}
>> +
>>   static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>>   				 struct v4l2_subdev_state *state, u32 pad,
>>   				 u64 streams_mask)
>>   {
>>   	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +	u64 sink_streams;
>>   	int ret;
>>   
>> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
>> +						       CSI2RX_PAD_SINK,
>> +						       &streams_mask);
>> +
>>   	/*
>>   	 * If we're not the first users, there's no need to
>>   	 * enable the whole controller.
>>   	 */
>>   	if (!csi2rx->count) {
>> +		csi2rx_update_vc_select(csi2rx, state);
>>   		ret = csi2rx_start(csi2rx);
>>   		if (ret)
>>   			return ret;
>> @@ -505,10 +556,11 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>>   
>>   	/* Start streaming on the source */
>>   	ret = v4l2_subdev_enable_streams(csi2rx->source_subdev, csi2rx->source_pad,
>> -					 BIT(0));
>> +					 sink_streams);
>>   	if (ret) {
>>   		dev_err(csi2rx->dev,
>> -			"Failed to start streams %d on subdev\n", 0);
>> +			"Failed to start streams %#llx on subdev\n",
>> +			sink_streams);
>>   		if (!csi2rx->count)
>>   			csi2rx_stop(csi2rx);
>>   		return ret;
>> @@ -523,9 +575,14 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>>   				  u64 streams_mask)
>>   {
>>   	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +	u64 sink_streams;
>> +
>> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
>> +						       CSI2RX_PAD_SINK,
>> +						       &streams_mask);
>>   
>>   	if (v4l2_subdev_disable_streams(csi2rx->source_subdev,
>> -					csi2rx->source_pad, BIT(0))) {
>> +						 csi2rx->source_pad, sink_streams)) {
>>   		dev_err(csi2rx->dev, "Couldn't disable our subdev\n");
>>   	}
>>   
>> @@ -538,6 +595,36 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>>   	return 0;
>>   }
>>   
>> +static int csi2rx_s_stream_fallback(struct v4l2_subdev *sd, int enable)
> What do you need this for? I presume you'd have a sub-device driver
> downstream calling this, but wouldn't you always use {en,dis}able_streams
> from that driver?


Yes, Downstream consumer driver that call this are TI Shim and StarFive 
JH7110 CAMSS. TI Shim uses {en,dis}able_streams, the StarFive JH7110 
CAMSS calls the s_stream. I will change the StarFive JH7110 CAMSS to use 
{en,dis}able_streams.


Rishikesh

>
>> +{
>> +	struct v4l2_subdev_state *state;
>> +	struct v4l2_subdev_route *route;
>> +	u64 mask[CSI2RX_PAD_MAX] = {0};
>> +	int i, ret;
>> +
>> +	/* Find the stream mask on all source pads */
>> +	state = v4l2_subdev_lock_and_get_active_state(sd);
>> +	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
>> +		for_each_active_route(&state->routing, route) {
>> +			if (route->source_pad == i)
>> +				mask[i] |= BIT_ULL(route->source_stream);
>> +		}
>> +	}
>> +	v4l2_subdev_unlock_state(state);
>> +
>> +	/* Start streaming on each pad */
>> +	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
>> +		if (enable)
>> +			ret = v4l2_subdev_enable_streams(sd, i, mask[i]);
>> +		else
>> +			ret = v4l2_subdev_disable_streams(sd, i, mask[i]);
>> +		if (ret)
>> +			return ret;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>   static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>>   				 struct v4l2_subdev_state *state,
>>   				 struct v4l2_subdev_mbus_code_enum *code_enum)
>> @@ -550,12 +637,56 @@ static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>>   	return 0;
>>   }
>>   
>> +static int _csi2rx_set_routing(struct v4l2_subdev *subdev,
>> +			       struct v4l2_subdev_state *state,
>> +			       struct v4l2_subdev_krouting *routing)
>> +{
>> +	static const struct v4l2_mbus_framefmt format = {
>> +		.width = 640,
>> +		.height = 480,
>> +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
>> +		.field = V4L2_FIELD_NONE,
>> +		.colorspace = V4L2_COLORSPACE_SRGB,
>> +		.ycbcr_enc = V4L2_YCBCR_ENC_601,
>> +		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
>> +		.xfer_func = V4L2_XFER_FUNC_SRGB,
>> +	};
>> +	int ret;
>> +
>> +	if (routing->num_routes > V4L2_FRAME_DESC_ENTRY_MAX)
>> +		return -EINVAL;
>> +
>> +	ret = v4l2_subdev_routing_validate(subdev, routing,
>> +					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return v4l2_subdev_set_routing_with_fmt(subdev, state, routing, &format);
>> +}
>> +
>> +static int csi2rx_set_routing(struct v4l2_subdev *subdev,
>> +			      struct v4l2_subdev_state *state,
>> +			      enum v4l2_subdev_format_whence which,
>> +			      struct v4l2_subdev_krouting *routing)
>> +{
>> +	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +	int ret;
>> +
>> +	if (which == V4L2_SUBDEV_FORMAT_ACTIVE && csi2rx->count)
>> +		return -EBUSY;
>> +
>> +	ret = _csi2rx_set_routing(subdev, state, routing);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> +
>>   static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>>   			  struct v4l2_subdev_state *state,
>>   			  struct v4l2_subdev_format *format)
>>   {
>>   	struct v4l2_mbus_framefmt *fmt;
>> -	unsigned int i;
>>   
>>   	/* No transcoding, source and sink formats must match. */
>>   	if (format->pad != CSI2RX_PAD_SINK)
>> @@ -567,14 +698,16 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>>   	format->format.field = V4L2_FIELD_NONE;
>>   
>>   	/* Set sink format */
>> -	fmt = v4l2_subdev_state_get_format(state, format->pad);
>> +	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
>>   	*fmt = format->format;
>>   
>> -	/* Propagate to source formats */
>> -	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
>> -		fmt = v4l2_subdev_state_get_format(state, i);
>> -		*fmt = format->format;
>> -	}
>> +	/* Propagate to source format */
>> +	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
>> +							   format->stream);
>> +	if (!fmt)
>> +		return -EINVAL;
>> +
>> +	*fmt = format->format;
>>   
>>   	return 0;
>>   }
>> @@ -582,21 +715,22 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>>   static int csi2rx_init_state(struct v4l2_subdev *subdev,
>>   			     struct v4l2_subdev_state *state)
>>   {
>> -	struct v4l2_subdev_format format = {
>> -		.pad = CSI2RX_PAD_SINK,
>> -		.format = {
>> -			.width = 640,
>> -			.height = 480,
>> -			.code = MEDIA_BUS_FMT_UYVY8_1X16,
>> -			.field = V4L2_FIELD_NONE,
>> -			.colorspace = V4L2_COLORSPACE_SRGB,
>> -			.ycbcr_enc = V4L2_YCBCR_ENC_601,
>> -			.quantization = V4L2_QUANTIZATION_LIM_RANGE,
>> -			.xfer_func = V4L2_XFER_FUNC_SRGB,
>> +	struct v4l2_subdev_route routes[] = {
>> +		{
>> +			.sink_pad = CSI2RX_PAD_SINK,
>> +			.sink_stream = 0,
>> +			.source_pad = CSI2RX_PAD_SOURCE_STREAM0,
>> +			.source_stream = 0,
>> +			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
>>   		},
>>   	};
>>   
>> -	return csi2rx_set_fmt(subdev, state, &format);
>> +	struct v4l2_subdev_krouting routing = {
>> +		.num_routes = ARRAY_SIZE(routes),
>> +		.routes = routes,
>> +	};
>> +
>> +	return _csi2rx_set_routing(subdev, state, &routing);
>>   }
>>   
>>   int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
>> @@ -630,17 +764,70 @@ static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
>>   				 struct v4l2_mbus_frame_desc *fd)
>>   {
>>   	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +	struct v4l2_mbus_frame_desc source_fd = {0};
>> +	struct v4l2_subdev_route *route;
>> +	struct v4l2_subdev_state *state;
>> +	int ret;
>> +
>> +	ret = csi2rx_get_frame_desc_from_source(csi2rx, &source_fd);
>> +	if (ret)
>> +		return ret;
>> +
>> +	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
>> +
>> +	state = v4l2_subdev_lock_and_get_active_state(subdev);
>> +
>> +	for_each_active_route(&state->routing, route) {
>> +		struct v4l2_mbus_frame_desc_entry *source_entry = NULL;
>> +		unsigned int i;
>> +
>> +		if (route->source_pad != pad)
>> +			continue;
>> +
>> +		for (i = 0; i < source_fd.num_entries; i++) {
>> +			if (source_fd.entry[i].stream == route->sink_stream) {
>> +				source_entry = &source_fd.entry[i];
>> +				break;
>> +			}
>> +		}
>> +
>> +		if (!source_entry) {
>> +			dev_err(csi2rx->dev,
>> +				"Failed to find stream from source frame desc\n");
>> +			ret = -EPIPE;
>> +			goto err_missing_stream;
>> +		}
>> +
>> +		fd->entry[fd->num_entries].stream = route->source_stream;
>> +		fd->entry[fd->num_entries].flags = source_entry->flags;
>> +		fd->entry[fd->num_entries].length = source_entry->length;
>> +		fd->entry[fd->num_entries].pixelcode = source_entry->pixelcode;
>> +		fd->entry[fd->num_entries].bus.csi2.vc =
>> +			source_entry->bus.csi2.vc;
>> +		fd->entry[fd->num_entries].bus.csi2.dt =
>> +			source_entry->bus.csi2.dt;
>> +
>> +		fd->num_entries++;
>> +	}
>> +
>> +err_missing_stream:
>> +	v4l2_subdev_unlock_state(state);
>>   
>> -	return csi2rx_get_frame_desc_from_source(csi2rx, fd);
>> +	return ret;
>>   }
>>   
>>   static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
>> -	.enum_mbus_code	= csi2rx_enum_mbus_code,
>> -	.get_fmt	= v4l2_subdev_get_fmt,
>> -	.set_fmt	= csi2rx_set_fmt,
>> -	.enable_streams         = csi2rx_enable_streams,
>> -	.disable_streams        = csi2rx_disable_streams,
>> -	.get_frame_desc	= csi2rx_get_frame_desc,
>> +	.enum_mbus_code		= csi2rx_enum_mbus_code,
>> +	.get_fmt		= v4l2_subdev_get_fmt,
>> +	.set_fmt		= csi2rx_set_fmt,
>> +	.get_frame_desc		= csi2rx_get_frame_desc,
>> +	.set_routing		= csi2rx_set_routing,
>> +	.enable_streams		= csi2rx_enable_streams,
>> +	.disable_streams	= csi2rx_disable_streams,
>> +};
>> +
>> +static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
>> +	.s_stream	= csi2rx_s_stream_fallback,
>>   };
>>   
>>   static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>> @@ -649,6 +836,7 @@ static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>>   
>>   static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
>>   	.core		= &csi2rx_core_ops,
>> +	.video		= &csi2rx_video_ops,
>>   	.pad		= &csi2rx_pad_ops,
>>   };
>>   
>> @@ -876,7 +1064,8 @@ static int csi2rx_probe(struct platform_device *pdev)
>>   	csi2rx->pads[CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>   	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
>>   		csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
>> -	csi2rx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>> +	csi2rx->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE |
>> +		V4L2_SUBDEV_FL_STREAMS;
>>   	csi2rx->subdev.entity.ops = &csi2rx_media_ops;
>>   
>>   	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,

Re: [PATCH v8 12/18] media: cadence: csi2rx: add multistream support

[Rishikesh Donadkar]

On 20/11/25 18:44, Tomi Valkeinen wrote:
> Hi,


Hi Tomi,

Thank you for the review !

>
> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
>> From: Jai Luthra <j-luthra@ti.com>
>>
>> Cadence CSI-2 bridge IP supports capturing multiple virtual "streams"
>> of data over the same physical interface using MIPI Virtual Channels.
>>
>> While the hardware IP supports usecases where streams coming in the sink
>> pad can be broadcasted to multiple source pads, the driver will need
>> significant re-architecture to make that possible. The two users of this
>> IP in mainline linux are TI Shim and StarFive JH7110 CAMSS, and both
>> have only integrated the first source pad i.e stream0 of this IP. So for
>> now keep it simple and only allow 1-to-1 mapping of streams from sink to
>> source, without any broadcasting.
>>
>> Implement a fallback s_stream hook that internally calls enable_stream
>> on each source pad, for consumer drivers that don't use multi-stream
> Hmm... So earlier in this series the .s_stream was removed from
> cdns-csi2rx. Did that break the "consumer drivers that don't use
> multi-stream"? What are those consumers? I assume it means j7-csi2rx and
> the above-mentioned starfive camss?
>
> Change the starfive camss to use v4l2_subdev_enable_streams() before the
> patch that converts cdns-csi2rx from .s_stream to .enable_stream?


Okay, will add one more patch to do this.


Rishikesh

>
>   Tomi
>
>> APIs to still work. The helper function v4l2_subdev_s_stream_helper()
>> form the v4l2 framework is not used here as it is meant only for the
>> subedvs that have a single source pad and this hardware IP supports
>> having multiple source pads.
>>
>> Signed-off-by: Jai Luthra <j-luthra@ti.com>
>> Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
>> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
>> Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> ---
>>   drivers/media/platform/cadence/cdns-csi2rx.c | 283 ++++++++++++++++---
>>   1 file changed, 236 insertions(+), 47 deletions(-)
>>
>> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
>> index 3688077fa8347..833bc134f17cb 100644
>> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
>> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
>> @@ -135,6 +135,7 @@ struct csi2rx_priv {
>>   	struct phy			*dphy;
>>   
>>   	u8				num_pixels[CSI2RX_STREAMS_MAX];
>> +	u32				vc_select[CSI2RX_STREAMS_MAX];
>>   	u8				lanes[CSI2RX_LANES_MAX];
>>   	u8				num_lanes;
>>   	u8				max_lanes;
>> @@ -273,30 +274,43 @@ static void csi2rx_reset(struct csi2rx_priv *csi2rx)
>>   
>>   static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
>>   {
>> -	struct media_pad *src_pad =
>> -		&csi2rx->source_subdev->entity.pads[csi2rx->source_pad];
>>   	union phy_configure_opts opts = { };
>>   	struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
>> -	struct v4l2_subdev_state *state;
>>   	struct v4l2_mbus_framefmt *framefmt;
>> +	struct v4l2_subdev_state *state;
>>   	const struct csi2rx_fmt *fmt;
>> +	int source_pad = csi2rx->source_pad;
>> +	struct media_pad *pad = &csi2rx->source_subdev->entity.pads[source_pad];
>>   	s64 link_freq;
>>   	int ret;
>> +	u32 bpp;
>>   
>>   	state = v4l2_subdev_get_locked_active_state(&csi2rx->subdev);
>>   
>> -	framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
>> -	if (!framefmt) {
>> -		dev_err(csi2rx->dev, "Did not find active sink format\n");
>> -		return -EINVAL;
>> -	}
>> +	/*
>> +	 * For multi-stream transmitters there is no single pixel rate.
>> +	 *
>> +	 * In multistream usecase pass bpp as 0 so that v4l2_get_link_freq()
>> +	 * returns an error if it falls back to V4L2_CID_PIXEL_RATE.
>> +	 */
>> +	if (state->routing.num_routes > 1) {
>> +		bpp = 0;
>> +	} else {
>> +		framefmt = v4l2_subdev_state_get_format(state, CSI2RX_PAD_SINK, 0);
>> +		if (!framefmt) {
>> +			dev_err(csi2rx->dev, "Did not find active sink format\n");
>> +			return -EINVAL;
>> +		}
>>   
>> -	fmt = csi2rx_get_fmt_by_code(framefmt->code);
>> +		fmt = csi2rx_get_fmt_by_code(framefmt->code);
>> +		bpp = fmt->bpp;
>> +	}
>>   
>> -	link_freq = v4l2_get_link_freq(src_pad,
>> -				       fmt->bpp, 2 * csi2rx->num_lanes);
>> -	if (link_freq < 0)
>> +	link_freq = v4l2_get_link_freq(pad, bpp, 2 * csi2rx->num_lanes);
>> +	if (link_freq < 0) {
>> +		dev_err(csi2rx->dev, "Unable to calculate link frequency\n");
>>   		return link_freq;
>> +	}
>>   
>>   	ret = phy_mipi_dphy_get_default_config_for_hsclk(link_freq,
>>   							 csi2rx->num_lanes, cfg);
>> @@ -394,11 +408,7 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>>   					  csi2rx->num_pixels[i]),
>>   		       csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
>>   
>> -		/*
>> -		 * Enable one virtual channel. When multiple virtual channels
>> -		 * are supported this will have to be changed.
>> -		 */
>> -		writel(CSI2RX_STREAM_DATA_CFG_VC_SELECT(0),
>> +		writel(csi2rx->vc_select[i],
>>   		       csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));
>>   
>>   		writel(CSI2RX_STREAM_CTRL_START,
>> @@ -486,18 +496,59 @@ static int csi2rx_log_status(struct v4l2_subdev *sd)
>>   	return 0;
>>   }
>>   
>> +static void csi2rx_update_vc_select(struct csi2rx_priv *csi2rx,
>> +				    struct v4l2_subdev_state *state)
>> +{
>> +	struct v4l2_mbus_frame_desc fd = {0};
>> +	struct v4l2_subdev_route *route;
>> +	unsigned int i;
>> +	int ret;
>> +
>> +	/* Capture VC=0 by default */
>> +	for (i = 0; i < CSI2RX_STREAMS_MAX; i++)
>> +		csi2rx->vc_select[i] = CSI2RX_STREAM_DATA_CFG_VC_SELECT(0);
>> +
>> +	ret = csi2rx_get_frame_desc_from_source(csi2rx, &fd);
>> +	if (ret || fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
>> +		dev_dbg(csi2rx->dev,
>> +			"Failed to get source frame desc, allowing only VC=0\n");
>> +		return;
>> +	}
>> +
>> +	/* If source provides per-stream VC info, use it to filter by VC */
>> +	memset(csi2rx->vc_select, 0, sizeof(csi2rx->vc_select));
>> +
>> +	for_each_active_route(&state->routing, route) {
>> +		u32 cdns_stream = route->source_pad - CSI2RX_PAD_SOURCE_STREAM0;
>> +
>> +		for (i = 0; i < fd.num_entries; i++) {
>> +			if (fd.entry[i].stream != route->sink_stream)
>> +				continue;
>> +
>> +			csi2rx->vc_select[cdns_stream] |=
>> +				CSI2RX_STREAM_DATA_CFG_VC_SELECT(fd.entry[i].bus.csi2.vc);
>> +		}
>> +	}
>> +}
>> +
>>   static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>>   				 struct v4l2_subdev_state *state, u32 pad,
>>   				 u64 streams_mask)
>>   {
>>   	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +	u64 sink_streams;
>>   	int ret;
>>   
>> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
>> +						       CSI2RX_PAD_SINK,
>> +						       &streams_mask);
>> +
>>   	/*
>>   	 * If we're not the first users, there's no need to
>>   	 * enable the whole controller.
>>   	 */
>>   	if (!csi2rx->count) {
>> +		csi2rx_update_vc_select(csi2rx, state);
>>   		ret = csi2rx_start(csi2rx);
>>   		if (ret)
>>   			return ret;
>> @@ -505,10 +556,11 @@ static int csi2rx_enable_streams(struct v4l2_subdev *subdev,
>>   
>>   	/* Start streaming on the source */
>>   	ret = v4l2_subdev_enable_streams(csi2rx->source_subdev, csi2rx->source_pad,
>> -					 BIT(0));
>> +					 sink_streams);
>>   	if (ret) {
>>   		dev_err(csi2rx->dev,
>> -			"Failed to start streams %d on subdev\n", 0);
>> +			"Failed to start streams %#llx on subdev\n",
>> +			sink_streams);
>>   		if (!csi2rx->count)
>>   			csi2rx_stop(csi2rx);
>>   		return ret;
>> @@ -523,9 +575,14 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>>   				  u64 streams_mask)
>>   {
>>   	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +	u64 sink_streams;
>> +
>> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
>> +						       CSI2RX_PAD_SINK,
>> +						       &streams_mask);
>>   
>>   	if (v4l2_subdev_disable_streams(csi2rx->source_subdev,
>> -					csi2rx->source_pad, BIT(0))) {
>> +						 csi2rx->source_pad, sink_streams)) {
>>   		dev_err(csi2rx->dev, "Couldn't disable our subdev\n");
>>   	}
>>   
>> @@ -538,6 +595,36 @@ static int csi2rx_disable_streams(struct v4l2_subdev *subdev,
>>   	return 0;
>>   }
>>   
>> +static int csi2rx_s_stream_fallback(struct v4l2_subdev *sd, int enable)
>> +{
>> +	struct v4l2_subdev_state *state;
>> +	struct v4l2_subdev_route *route;
>> +	u64 mask[CSI2RX_PAD_MAX] = {0};
>> +	int i, ret;
>> +
>> +	/* Find the stream mask on all source pads */
>> +	state = v4l2_subdev_lock_and_get_active_state(sd);
>> +	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
>> +		for_each_active_route(&state->routing, route) {
>> +			if (route->source_pad == i)
>> +				mask[i] |= BIT_ULL(route->source_stream);
>> +		}
>> +	}
>> +	v4l2_subdev_unlock_state(state);
>> +
>> +	/* Start streaming on each pad */
>> +	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
>> +		if (enable)
>> +			ret = v4l2_subdev_enable_streams(sd, i, mask[i]);
>> +		else
>> +			ret = v4l2_subdev_disable_streams(sd, i, mask[i]);
>> +		if (ret)
>> +			return ret;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>   static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>>   				 struct v4l2_subdev_state *state,
>>   				 struct v4l2_subdev_mbus_code_enum *code_enum)
>> @@ -550,12 +637,56 @@ static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
>>   	return 0;
>>   }
>>   
>> +static int _csi2rx_set_routing(struct v4l2_subdev *subdev,
>> +			       struct v4l2_subdev_state *state,
>> +			       struct v4l2_subdev_krouting *routing)
>> +{
>> +	static const struct v4l2_mbus_framefmt format = {
>> +		.width = 640,
>> +		.height = 480,
>> +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
>> +		.field = V4L2_FIELD_NONE,
>> +		.colorspace = V4L2_COLORSPACE_SRGB,
>> +		.ycbcr_enc = V4L2_YCBCR_ENC_601,
>> +		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
>> +		.xfer_func = V4L2_XFER_FUNC_SRGB,
>> +	};
>> +	int ret;
>> +
>> +	if (routing->num_routes > V4L2_FRAME_DESC_ENTRY_MAX)
>> +		return -EINVAL;
>> +
>> +	ret = v4l2_subdev_routing_validate(subdev, routing,
>> +					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return v4l2_subdev_set_routing_with_fmt(subdev, state, routing, &format);
>> +}
>> +
>> +static int csi2rx_set_routing(struct v4l2_subdev *subdev,
>> +			      struct v4l2_subdev_state *state,
>> +			      enum v4l2_subdev_format_whence which,
>> +			      struct v4l2_subdev_krouting *routing)
>> +{
>> +	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +	int ret;
>> +
>> +	if (which == V4L2_SUBDEV_FORMAT_ACTIVE && csi2rx->count)
>> +		return -EBUSY;
>> +
>> +	ret = _csi2rx_set_routing(subdev, state, routing);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> +
>>   static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>>   			  struct v4l2_subdev_state *state,
>>   			  struct v4l2_subdev_format *format)
>>   {
>>   	struct v4l2_mbus_framefmt *fmt;
>> -	unsigned int i;
>>   
>>   	/* No transcoding, source and sink formats must match. */
>>   	if (format->pad != CSI2RX_PAD_SINK)
>> @@ -567,14 +698,16 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>>   	format->format.field = V4L2_FIELD_NONE;
>>   
>>   	/* Set sink format */
>> -	fmt = v4l2_subdev_state_get_format(state, format->pad);
>> +	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
>>   	*fmt = format->format;
>>   
>> -	/* Propagate to source formats */
>> -	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
>> -		fmt = v4l2_subdev_state_get_format(state, i);
>> -		*fmt = format->format;
>> -	}
>> +	/* Propagate to source format */
>> +	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
>> +							   format->stream);
>> +	if (!fmt)
>> +		return -EINVAL;
>> +
>> +	*fmt = format->format;
>>   
>>   	return 0;
>>   }
>> @@ -582,21 +715,22 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
>>   static int csi2rx_init_state(struct v4l2_subdev *subdev,
>>   			     struct v4l2_subdev_state *state)
>>   {
>> -	struct v4l2_subdev_format format = {
>> -		.pad = CSI2RX_PAD_SINK,
>> -		.format = {
>> -			.width = 640,
>> -			.height = 480,
>> -			.code = MEDIA_BUS_FMT_UYVY8_1X16,
>> -			.field = V4L2_FIELD_NONE,
>> -			.colorspace = V4L2_COLORSPACE_SRGB,
>> -			.ycbcr_enc = V4L2_YCBCR_ENC_601,
>> -			.quantization = V4L2_QUANTIZATION_LIM_RANGE,
>> -			.xfer_func = V4L2_XFER_FUNC_SRGB,
>> +	struct v4l2_subdev_route routes[] = {
>> +		{
>> +			.sink_pad = CSI2RX_PAD_SINK,
>> +			.sink_stream = 0,
>> +			.source_pad = CSI2RX_PAD_SOURCE_STREAM0,
>> +			.source_stream = 0,
>> +			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
>>   		},
>>   	};
>>   
>> -	return csi2rx_set_fmt(subdev, state, &format);
>> +	struct v4l2_subdev_krouting routing = {
>> +		.num_routes = ARRAY_SIZE(routes),
>> +		.routes = routes,
>> +	};
>> +
>> +	return _csi2rx_set_routing(subdev, state, &routing);
>>   }
>>   
>>   int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
>> @@ -630,17 +764,70 @@ static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
>>   				 struct v4l2_mbus_frame_desc *fd)
>>   {
>>   	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
>> +	struct v4l2_mbus_frame_desc source_fd = {0};
>> +	struct v4l2_subdev_route *route;
>> +	struct v4l2_subdev_state *state;
>> +	int ret;
>> +
>> +	ret = csi2rx_get_frame_desc_from_source(csi2rx, &source_fd);
>> +	if (ret)
>> +		return ret;
>> +
>> +	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
>> +
>> +	state = v4l2_subdev_lock_and_get_active_state(subdev);
>> +
>> +	for_each_active_route(&state->routing, route) {
>> +		struct v4l2_mbus_frame_desc_entry *source_entry = NULL;
>> +		unsigned int i;
>> +
>> +		if (route->source_pad != pad)
>> +			continue;
>> +
>> +		for (i = 0; i < source_fd.num_entries; i++) {
>> +			if (source_fd.entry[i].stream == route->sink_stream) {
>> +				source_entry = &source_fd.entry[i];
>> +				break;
>> +			}
>> +		}
>> +
>> +		if (!source_entry) {
>> +			dev_err(csi2rx->dev,
>> +				"Failed to find stream from source frame desc\n");
>> +			ret = -EPIPE;
>> +			goto err_missing_stream;
>> +		}
>> +
>> +		fd->entry[fd->num_entries].stream = route->source_stream;
>> +		fd->entry[fd->num_entries].flags = source_entry->flags;
>> +		fd->entry[fd->num_entries].length = source_entry->length;
>> +		fd->entry[fd->num_entries].pixelcode = source_entry->pixelcode;
>> +		fd->entry[fd->num_entries].bus.csi2.vc =
>> +			source_entry->bus.csi2.vc;
>> +		fd->entry[fd->num_entries].bus.csi2.dt =
>> +			source_entry->bus.csi2.dt;
>> +
>> +		fd->num_entries++;
>> +	}
>> +
>> +err_missing_stream:
>> +	v4l2_subdev_unlock_state(state);
>>   
>> -	return csi2rx_get_frame_desc_from_source(csi2rx, fd);
>> +	return ret;
>>   }
>>   
>>   static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
>> -	.enum_mbus_code	= csi2rx_enum_mbus_code,
>> -	.get_fmt	= v4l2_subdev_get_fmt,
>> -	.set_fmt	= csi2rx_set_fmt,
>> -	.enable_streams         = csi2rx_enable_streams,
>> -	.disable_streams        = csi2rx_disable_streams,
>> -	.get_frame_desc	= csi2rx_get_frame_desc,
>> +	.enum_mbus_code		= csi2rx_enum_mbus_code,
>> +	.get_fmt		= v4l2_subdev_get_fmt,
>> +	.set_fmt		= csi2rx_set_fmt,
>> +	.get_frame_desc		= csi2rx_get_frame_desc,
>> +	.set_routing		= csi2rx_set_routing,
>> +	.enable_streams		= csi2rx_enable_streams,
>> +	.disable_streams	= csi2rx_disable_streams,
>> +};
>> +
>> +static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
>> +	.s_stream	= csi2rx_s_stream_fallback,
>>   };
>>   
>>   static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>> @@ -649,6 +836,7 @@ static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
>>   
>>   static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
>>   	.core		= &csi2rx_core_ops,
>> +	.video		= &csi2rx_video_ops,
>>   	.pad		= &csi2rx_pad_ops,
>>   };
>>   
>> @@ -876,7 +1064,8 @@ static int csi2rx_probe(struct platform_device *pdev)
>>   	csi2rx->pads[CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>   	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
>>   		csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
>> -	csi2rx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>> +	csi2rx->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE |
>> +		V4L2_SUBDEV_FL_STREAMS;
>>   	csi2rx->subdev.entity.ops = &csi2rx_media_ops;
>>   
>>   	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,

Re: [PATCH v8 13/18] media: ti: j721e-csi2rx: add multistream support

[Rishikesh Donadkar]

On 01/12/25 18:33, Tomi Valkeinen wrote:
> Hi,


Hi Tomi,

Thank you for the review !

>
> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
>> From: Jai Luthra <j-luthra@ti.com>
>>
>> Each CSI2 stream can be multiplexed into 4 independent streams, each
> Well, that's not true, at least generally speaking (there can be more
> than 4). Is that specific to TI hardware?


Yes, The commit message talks about how TI CSI does the multiplexing of 
CSI stream from the sensor into 4 streams as show in the Figure 12-388 
in AM62A TRM[1]. I will modify the commit message to mention that this 
is TI CSI specific.


[1]: 
https://www.ti.com/lit/ug/spruj16c/spruj16c.pdf?ts=1765273774405&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FAM62A7


>
>> identified by its virtual channel number and data type. The incoming
>> data from these streams can be filtered on the basis of either the
>> virtual channel or the data type.
>>
>> To capture this multiplexed stream, the application needs to tell
>> the driver how it wants to route the data. It needs to specify
>> which context should process which stream. This is done via the
>> new routing APIs.
>>
>> Add ioctls to accept routing information from the application and save
>> that in the driver. This can be used when starting streaming on a
>> context to determine which route and consequently which virtual channel
>> it should process.
>>
>> De-assert the pixel interface reset on first start_streaming() and assert
>> it on the last stop_streaming().
>>
>> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
>> Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
>> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
>> Signed-off-by: Jai Luthra <j-luthra@ti.com>
>> Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
>> ---
>>   .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 224 ++++++++++++++----
>>   1 file changed, 179 insertions(+), 45 deletions(-)
>>
>> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> index 126a62fa2c4c4..c8e0e761f2802 100644
>> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
>> @@ -103,6 +103,7 @@ struct ti_csi2rx_dev;
>>   
>>   struct ti_csi2rx_ctx {
>>   	struct ti_csi2rx_dev		*csi;
>> +	struct v4l2_subdev_route        *route;
>>   	struct video_device		vdev;
>>   	struct vb2_queue		vidq;
>>   	struct mutex			mutex; /* To serialize ioctls. */
>> @@ -136,6 +137,7 @@ struct ti_csi2rx_dev {
>>   		dma_addr_t		paddr;
>>   		size_t			len;
>>   	} drain;
>> +	bool                            vc_cached;
>>   };
>>   
>>   static inline struct ti_csi2rx_dev *to_csi2rx_dev(struct v4l2_subdev *sd)
>> @@ -143,17 +145,6 @@ static inline struct ti_csi2rx_dev *to_csi2rx_dev(struct v4l2_subdev *sd)
>>   	return container_of(sd, struct ti_csi2rx_dev, subdev);
>>   }
>>   
>> -static const struct v4l2_mbus_framefmt ti_csi2rx_default_fmt = {
>> -	.width = 640,
>> -	.height = 480,
>> -	.code = MEDIA_BUS_FMT_UYVY8_1X16,
>> -	.field = V4L2_FIELD_NONE,
>> -	.colorspace = V4L2_COLORSPACE_SRGB,
>> -	.ycbcr_enc = V4L2_YCBCR_ENC_601,
>> -	.quantization = V4L2_QUANTIZATION_LIM_RANGE,
>> -	.xfer_func = V4L2_XFER_FUNC_SRGB,
>> -};
>> -
>>   static const struct ti_csi2rx_fmt ti_csi2rx_formats[] = {
>>   	{
>>   		.fourcc			= V4L2_PIX_FMT_YUYV,
>> @@ -566,8 +557,10 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
>>   	fmt = find_format_by_fourcc(ctx->v_fmt.fmt.pix.pixelformat);
>>   
>>   	/* De-assert the pixel interface reset. */
>> -	reg = SHIM_CNTL_PIX_RST;
>> -	writel(reg, csi->shim + SHIM_CNTL);
>> +	if (!csi->enable_count) {
>> +		reg = SHIM_CNTL_PIX_RST;
>> +		writel(reg, csi->shim + SHIM_CNTL);
>> +	}
>>   
>>   	/* Negotiate pixel count from the source */
>>   	ti_csi2rx_request_max_ppc(csi);
>> @@ -888,30 +881,80 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
>>   	}
>>   }
>>   
>> +static int ti_csi2rx_get_route(struct ti_csi2rx_ctx *ctx)
>> +{
>> +	struct ti_csi2rx_dev *csi = ctx->csi;
>> +	struct media_pad *pad;
>> +	struct v4l2_subdev_state *state;
>> +	struct v4l2_subdev_route *r;
>> +
>> +	/* Get the source pad connected to this ctx */
>> +	pad = media_entity_remote_source_pad_unique(ctx->pad.entity);
>> +	if (!pad) {
>> +		dev_err(csi->dev, "No pad connected to ctx %d\n", ctx->idx);
>> +		return -ENODEV;
>> +	}
>> +
>> +	state = v4l2_subdev_lock_and_get_active_state(&csi->subdev);
> This looks a bit concerning. You lock the state, find the correct route
> and store a pointer to the route into the ctx, then unlock the state...
> Alarm bells should be ringing here.


Thank you for pointing out, I will store the stream number instead of 
storing the pointer for route, here we don't allow anyone to update the 
routes when we are in streaming (i.e. if csi->enable_count > 0, return 
-EBUSY). So, the stream number is not likely to change.

>
>> +
>> +	for_each_active_route(&state->routing, r) {
>> +		if (!(r->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE))
> for_each_active_route() already checks this ("_active_").


Okay, I will remove the check for active route.

>
>> +			continue;
>> +		if (r->source_pad != pad->index)
>> +			continue;
>> +
>> +		ctx->route = r;
> Shouldn't you break here?


Right, I will add a break here

>
>> +	}
>> +
>> +	v4l2_subdev_unlock_state(state);
>> +
>> +	if (!ctx->route)
>> +		return -ENODEV;
>> +
>> +	return 0;
>> +}
>> +
>>   static int ti_csi2rx_get_vc(struct ti_csi2rx_ctx *ctx)
>>   {
>>   	struct ti_csi2rx_dev *csi = ctx->csi;
>> +	struct ti_csi2rx_ctx *curr_ctx;
>>   	struct v4l2_mbus_frame_desc fd;
>> -	struct media_pad *pad;
>> -	int ret, i;
>> +	struct media_pad *source_pad;
>> +	struct v4l2_subdev_route *curr_route;
>> +	int ret;
>> +	unsigned int i, j;
>>   
>> -	pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
>> -	if (!pad)
>> +	/* Get the frame desc form source */
>> +	source_pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
>> +	if (!source_pad)
>>   		return -ENODEV;
>>   
>> -	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, pad->index, &fd);
>> +	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, source_pad->index, &fd);
>>   	if (ret)
>>   		return ret;
>>   
>>   	if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
>>   		return -EINVAL;
>>   
>> -	for (i = 0; i < fd.num_entries; i++) {
>> -		if (ctx->stream == fd.entry[i].stream)
>> -			return fd.entry[i].bus.csi2.vc;
>> +	for (i = 0; i < csi->num_ctx; i++) {
>> +		curr_ctx = &csi->ctx[i];
>> +
>> +		/* Capture VC 0 by default */
>> +		curr_ctx->vc = 0;
>> +
>> +		ret = ti_csi2rx_get_route(curr_ctx);
>> +		if (ret)
>> +			continue;
>> +
>> +		curr_route = curr_ctx->route;
>> +		curr_ctx->stream = curr_route->sink_stream;
>> +
>> +		for (j = 0; j < fd.num_entries; j++)
>> +			if (curr_ctx->stream == fd.entry[j].stream)
>> +				curr_ctx->vc = fd.entry[j].bus.csi2.vc;
>>   	}
>>   
>> -	return -ENODEV;
>> +	return 0;
>>   }
>>   
>>   static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>> @@ -934,13 +977,24 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>>   	if (ret)
>>   		goto err;
>>   
>> -	ret = ti_csi2rx_get_vc(ctx);
>> -	if (ret == -ENOIOCTLCMD)
>> -		ctx->vc = 0;
>> -	else if (ret < 0)
>> +	/* If no stream is routed to this ctx, exit early */
>> +	ret = ti_csi2rx_get_route(ctx);
>> +	if (ret)
>>   		goto err;
>> -	else
>> -		ctx->vc = ret;
>> +
>> +	/* Get the VC for all enabled ctx on first stream start */
> Is the comment right? How does this work? ti_csi2rx_get_vc() is passed a
> single context, but... it gets VCs for all contexts? And shouldn't these
> also be dealing with DT at the same time with VC?


Yes, here we pass a single context to ti_csi2rx_get_vc(), but we loop 
over all the ctx on first stream start.

I will modify this function to also deal with DT.

>
>> +	mutex_lock(&csi->mutex);
>> +	if (!csi->vc_cached) {
>> +		ret = ti_csi2rx_get_vc(ctx);
>> +		if (ret == -ENOIOCTLCMD) {
>> +			ctx->vc = 0;
>> +		} else if (ret < 0) {
>> +			mutex_unlock(&csi->mutex);
>> +			goto err;
>> +		}
>> +		csi->vc_cached = true;
>> +	}
>> +	mutex_unlock(&csi->mutex);
>>   
>>   	ti_csi2rx_setup_shim(ctx);
>>   
>> @@ -960,8 +1014,9 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
>>   	dma->state = TI_CSI2RX_DMA_ACTIVE;
>>   	spin_unlock_irqrestore(&dma->lock, flags);
>>   
>> +	/* Start stream 0, we don't allow multiple streams on the source pad */
>>   	ret = v4l2_subdev_enable_streams(&csi->subdev,
>> -					 TI_CSI2RX_PAD_FIRST_SOURCE,
>> +					 TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
>>   					 BIT(0));
>>   	if (ret)
>>   		goto err_dma;
>> @@ -985,17 +1040,26 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
>>   	struct ti_csi2rx_dev *csi = ctx->csi;
>>   	int ret;
>>   
>> -	video_device_pipeline_stop(&ctx->vdev);
>> +	mutex_lock(&csi->mutex);
>>   
>> -	writel(0, csi->shim + SHIM_CNTL);
>>   	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
>>   
>> +	/* assert pixel reset to prevent stale data */
>> +	if (csi->enable_count == 1) {
>> +		writel(0, csi->shim + SHIM_CNTL);
>> +		csi->vc_cached = false;
>> +	}
>> +
>> +	video_device_pipeline_stop(&ctx->vdev);
>> +
>>   	ret = v4l2_subdev_disable_streams(&csi->subdev,
>> -					  TI_CSI2RX_PAD_FIRST_SOURCE,
>> +					  TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx,
>>   					  BIT(0));
>>   	if (ret)
>>   		dev_err(csi->dev, "Failed to stop subdev stream\n");
>>   
>> +	mutex_unlock(&csi->mutex);
>> +
>>   	ti_csi2rx_stop_dma(ctx);
>>   	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
>>   }
>> @@ -1038,25 +1102,84 @@ static int ti_csi2rx_sd_set_fmt(struct v4l2_subdev *sd,
>>   	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
>>   	*fmt = format->format;
>>   
>> -	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE,
>> -					   format->stream);
>> +	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
>> +							   format->stream);
>> +	if (!fmt)
>> +		return -EINVAL;
>> +
>>   	*fmt = format->format;
>>   
>>   	return 0;
>>   }
>>   
>> -static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
>> -				   struct v4l2_subdev_state *state)
>> +static int _ti_csi2rx_sd_set_routing(struct v4l2_subdev *sd,
>> +				     struct v4l2_subdev_state *state,
>> +				     struct v4l2_subdev_krouting *routing)
>>   {
>> -	struct v4l2_mbus_framefmt *fmt;
>> +	int ret;
>>   
>> -	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_SINK);
>> -	*fmt = ti_csi2rx_default_fmt;
>> +	const struct v4l2_mbus_framefmt format = {
> "static const"


Okay


Rishikesh

>
>> +		.width = 640,
>> +		.height = 480,
>> +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
>> +		.field = V4L2_FIELD_NONE,
>> +		.colorspace = V4L2_COLORSPACE_SRGB,
>> +		.ycbcr_enc = V4L2_YCBCR_ENC_601,
>> +		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
>> +		.xfer_func = V4L2_XFER_FUNC_SRGB,
>> +	};
>>   
>> -	fmt = v4l2_subdev_state_get_format(state, TI_CSI2RX_PAD_FIRST_SOURCE);
>> -	*fmt = ti_csi2rx_default_fmt;
>> +	ret = v4l2_subdev_routing_validate(sd, routing,
>> +					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1 |
>> +					   V4L2_SUBDEV_ROUTING_NO_SOURCE_MULTIPLEXING);
>>   
>> -	return 0;
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Only stream ID 0 allowed on source pads */
>> +	for (unsigned int i = 0; i < routing->num_routes; ++i) {
>> +		const struct v4l2_subdev_route *route = &routing->routes[i];
>> +
>> +		if (route->source_stream != 0)
>> +			return -EINVAL;
>> +	}
>> +
>> +	ret = v4l2_subdev_set_routing_with_fmt(sd, state, routing, &format);
>> +
>> +	return ret;
>> +}
>> +
>> +static int ti_csi2rx_sd_set_routing(struct v4l2_subdev *sd,
>> +				    struct v4l2_subdev_state *state,
>> +				    enum v4l2_subdev_format_whence which,
>> +				    struct v4l2_subdev_krouting *routing)
>> +{
>> +	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
>> +
>> +	if (csi->enable_count > 0)
>> +		return -EBUSY;
>> +
>> +	return _ti_csi2rx_sd_set_routing(sd, state, routing);
>> +}
>> +
>> +static int ti_csi2rx_sd_init_state(struct v4l2_subdev *sd,
>> +				   struct v4l2_subdev_state *state)
>> +{
>> +	struct v4l2_subdev_route routes[] = { {
>> +		.sink_pad = 0,
>> +		.sink_stream = 0,
>> +		.source_pad = TI_CSI2RX_PAD_FIRST_SOURCE,
>> +		.source_stream = 0,
>> +		.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
>> +	} };
>> +
>> +	struct v4l2_subdev_krouting routing = {
>> +		.num_routes = 1,
>> +		.routes = routes,
>> +	};
>> +
>> +	/* Initialize routing to single route to the fist source pad */
>> +	return _ti_csi2rx_sd_set_routing(sd, state, &routing);
>>   }
>>   
>>   static int ti_csi2rx_sd_enable_streams(struct v4l2_subdev *sd,
>> @@ -1065,14 +1188,18 @@ static int ti_csi2rx_sd_enable_streams(struct v4l2_subdev *sd,
>>   {
>>   	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
>>   	struct media_pad *remote_pad;
>> +	u64 sink_streams;
>>   	int ret = 0;
>>   
>>   	remote_pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
>>   	if (!remote_pad)
>>   		return -ENODEV;
>> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
>> +						       TI_CSI2RX_PAD_SINK,
>> +						       &streams_mask);
>>   
>>   	ret = v4l2_subdev_enable_streams(csi->source, remote_pad->index,
>> -					 BIT(0));
>> +					 sink_streams);
>>   	if (ret)
>>   		return ret;
>>   
>> @@ -1087,17 +1214,21 @@ static int ti_csi2rx_sd_disable_streams(struct v4l2_subdev *sd,
>>   {
>>   	struct ti_csi2rx_dev *csi = to_csi2rx_dev(sd);
>>   	struct media_pad *remote_pad;
>> +	u64 sink_streams;
>>   	int ret = 0;
>>   
>>   	remote_pad = media_entity_remote_source_pad_unique(&csi->subdev.entity);
>>   	if (!remote_pad)
>>   		return -ENODEV;
>> +	sink_streams = v4l2_subdev_state_xlate_streams(state, pad,
>> +						       TI_CSI2RX_PAD_SINK,
>> +						       &streams_mask);
>>   
>>   	if (csi->enable_count == 0)
>>   		return -EINVAL;
>>   
>>   	ret = v4l2_subdev_disable_streams(csi->source, remote_pad->index,
>> -					  BIT(0));
>> +					  sink_streams);
>>   	if (!ret)
>>   		--csi->enable_count;
>>   
>> @@ -1106,6 +1237,7 @@ static int ti_csi2rx_sd_disable_streams(struct v4l2_subdev *sd,
>>   
>>   static const struct v4l2_subdev_pad_ops ti_csi2rx_subdev_pad_ops = {
>>   	.enum_mbus_code	= ti_csi2rx_enum_mbus_code,
>> +	.set_routing = ti_csi2rx_sd_set_routing,
>>   	.get_fmt = v4l2_subdev_get_fmt,
>>   	.set_fmt = ti_csi2rx_sd_set_fmt,
>>   	.enable_streams = ti_csi2rx_sd_enable_streams,
>> @@ -1284,7 +1416,7 @@ static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
>>   	v4l2_subdev_init(sd, &ti_csi2rx_subdev_ops);
>>   	sd->internal_ops = &ti_csi2rx_internal_ops;
>>   	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
>> -	sd->flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
>> +	sd->flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_STREAMS;
>>   	strscpy(sd->name, dev_name(csi->dev), sizeof(sd->name));
>>   	sd->dev = csi->dev;
>>   	sd->entity.ops = &ti_csi2rx_subdev_entity_ops;
>> @@ -1347,6 +1479,8 @@ static int ti_csi2rx_init_ctx(struct ti_csi2rx_ctx *ctx)
>>   
>>   	ti_csi2rx_fill_fmt(fmt, &ctx->v_fmt);
>>   
>> +	ctx->route = NULL;
>> +
>>   	ctx->pad.flags = MEDIA_PAD_FL_SINK;
>>   	vdev->entity.ops = &ti_csi2rx_video_entity_ops;
>>   	ret = media_entity_pads_init(&ctx->vdev.entity, 1, &ctx->pad);

Re: [PATCH v8 13/18] media: ti: j721e-csi2rx: add multistream support

[Jai Luthra]

Hi Rishikesh,

Quoting Rishikesh Donadkar (2025-12-09 15:38:33)
> 
> On 01/12/25 18:33, Tomi Valkeinen wrote:
> > Hi,
> 
> 
> Hi Tomi,
> 
> Thank you for the review !
> 
> >
> > On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> >> From: Jai Luthra <j-luthra@ti.com>
> >>
> >> Each CSI2 stream can be multiplexed into 4 independent streams, each
> > Well, that's not true, at least generally speaking (there can be more
> > than 4). Is that specific to TI hardware?
> 
> 
> Yes, The commit message talks about how TI CSI does the multiplexing of 
> CSI stream from the sensor into 4 streams as show in the Figure 12-388 
> in AM62A TRM[1]. I will modify the commit message to mention that this 
> is TI CSI specific.

Figure 12-388 shows the internal pixel stream coming from Cadence to
different hardware blocks like TI's Shim (DMA) and VP0 (ISP) and VP1. I
don't see that being related to CSI2 VC/DT support, which is handled by the
Shim using different DMA contexts and channels.

In the TRM, under 12.6.1.1.1 CSI_RX_IF Features, I see:
 * Compliant to MIPI CSI v1.3
 * Supports up to 16 virtual channels per input (partial MIPI CSI v2.0 feature)

So 16 VCs is supported by TI's CSI pipeline, despite it being MIPI CSI2
v1.3 compliant otherwise. I think I might have been confused with DS90UB960
while writing this commit message originally, which strictly supports a
maximum of 4 VCs.

Secondly, even with just CSI2 v1.0 compliant source, this could
theoretically handle 8 "streams" of data with 4 different VCs x 2 data
types each. So please update the paragraph in next revision.

Thanks,
    Jai

> 
> 
> [1]: 
> https://www.ti.com/lit/ug/spruj16c/spruj16c.pdf?ts=1765273774405&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FAM62A7
> 
> 
> >
> >> identified by its virtual channel number and data type. The incoming
> >> data from these streams can be filtered on the basis of either the
> >> virtual channel or the data type.
> >>
> >> To capture this multiplexed stream, the application needs to tell
> >> the driver how it wants to route the data. It needs to specify
> >> which context should process which stream. This is done via the
> >> new routing APIs.
> >>
> >> Add ioctls to accept routing information from the application and save
> >> that in the driver. This can be used when starting streaming on a
> >> context to determine which route and consequently which virtual channel
> >> it should process.
> >>
> >> De-assert the pixel interface reset on first start_streaming() and assert
> >> it on the last stop_streaming().
> >>
> >> Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
> >> Co-developed-by: Pratyush Yadav <p.yadav@ti.com>
> >> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> >> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> >> Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
> >> Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
> >> ---
> >>   .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 224 ++++++++++++++----
> >>   1 file changed, 179 insertions(+), 45 deletions(-)

[snip]

Re: [PATCH v8 13/18] media: ti: j721e-csi2rx: add multistream support

[Tomi Valkeinen]

Hi,

On 09/12/2025 12:36, Jai Luthra wrote:
> Hi Rishikesh,
> 
> Quoting Rishikesh Donadkar (2025-12-09 15:38:33)
>>
>> On 01/12/25 18:33, Tomi Valkeinen wrote:
>>> Hi,
>>
>>
>> Hi Tomi,
>>
>> Thank you for the review !
>>
>>>
>>> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
>>>> From: Jai Luthra <j-luthra@ti.com>
>>>>
>>>> Each CSI2 stream can be multiplexed into 4 independent streams, each
>>> Well, that's not true, at least generally speaking (there can be more
>>> than 4). Is that specific to TI hardware?
>>
>>
>> Yes, The commit message talks about how TI CSI does the multiplexing of 
>> CSI stream from the sensor into 4 streams as show in the Figure 12-388 
>> in AM62A TRM[1]. I will modify the commit message to mention that this 
>> is TI CSI specific.
> 
> Figure 12-388 shows the internal pixel stream coming from Cadence to
> different hardware blocks like TI's Shim (DMA) and VP0 (ISP) and VP1. I
> don't see that being related to CSI2 VC/DT support, which is handled by the
> Shim using different DMA contexts and channels.
> 
> In the TRM, under 12.6.1.1.1 CSI_RX_IF Features, I see:
>  * Compliant to MIPI CSI v1.3
>  * Supports up to 16 virtual channels per input (partial MIPI CSI v2.0 feature)
> 
> So 16 VCs is supported by TI's CSI pipeline, despite it being MIPI CSI2
> v1.3 compliant otherwise. I think I might have been confused with DS90UB960
> while writing this commit message originally, which strictly supports a
> maximum of 4 VCs.
> 
> Secondly, even with just CSI2 v1.0 compliant source, this could
> theoretically handle 8 "streams" of data with 4 different VCs x 2 data
> types each. So please update the paragraph in next revision.
Where does the "8" come from? Do we have 8 context registers, to which
we program the VC + DT filter?

Also, it could as well be 8 streams, all with VC 0, but each different
DT (probably unlikely scenario =). But I just want to highlight that VC
is not the "stream". The "stream" is the VC+DT tuple.

 Tomi

Re: [PATCH v8 13/18] media: ti: j721e-csi2rx: add multistream support

[Jai Luthra]

Quoting Tomi Valkeinen (2025-12-09 17:22:08)
> Hi,
> 
> On 09/12/2025 12:36, Jai Luthra wrote:
> > Hi Rishikesh,
> > 
> > Quoting Rishikesh Donadkar (2025-12-09 15:38:33)
> >>
> >> On 01/12/25 18:33, Tomi Valkeinen wrote:
> >>> Hi,
> >>
> >>
> >> Hi Tomi,
> >>
> >> Thank you for the review !
> >>
> >>>
> >>> On 12/11/2025 13:54, Rishikesh Donadkar wrote:
> >>>> From: Jai Luthra <j-luthra@ti.com>
> >>>>
> >>>> Each CSI2 stream can be multiplexed into 4 independent streams, each
> >>> Well, that's not true, at least generally speaking (there can be more
> >>> than 4). Is that specific to TI hardware?
> >>
> >>
> >> Yes, The commit message talks about how TI CSI does the multiplexing of 
> >> CSI stream from the sensor into 4 streams as show in the Figure 12-388 
> >> in AM62A TRM[1]. I will modify the commit message to mention that this 
> >> is TI CSI specific.
> > 
> > Figure 12-388 shows the internal pixel stream coming from Cadence to
> > different hardware blocks like TI's Shim (DMA) and VP0 (ISP) and VP1. I
> > don't see that being related to CSI2 VC/DT support, which is handled by the
> > Shim using different DMA contexts and channels.
> > 
> > In the TRM, under 12.6.1.1.1 CSI_RX_IF Features, I see:
> >  * Compliant to MIPI CSI v1.3
> >  * Supports up to 16 virtual channels per input (partial MIPI CSI v2.0 feature)
> > 
> > So 16 VCs is supported by TI's CSI pipeline, despite it being MIPI CSI2
> > v1.3 compliant otherwise. I think I might have been confused with DS90UB960
> > while writing this commit message originally, which strictly supports a
> > maximum of 4 VCs.
> > 
> > Secondly, even with just CSI2 v1.0 compliant source, this could
> > theoretically handle 8 "streams" of data with 4 different VCs x 2 data
> > types each. So please update the paragraph in next revision.
> Where does the "8" come from? Do we have 8 context registers, to which
> we program the VC + DT filter?

Indeed, 8 was just an example. The hardware can support upto 32
combinations, as that is the total number of DMA contexts available.

Thanks,
    Jai

> 
> Also, it could as well be 8 streams, all with VC 0, but each different
> DT (probably unlikely scenario =). But I just want to highlight that VC
> is not the "stream". The "stream" is the VC+DT tuple.
> 
>  Tomi
>