* [PATCH v2 0/2] Add bindings and driver for Sony IMX908
@ 2026-08-06 7:09 Lachlan Michael
2026-08-06 7:09 ` [PATCH v2 1/2] media: dt-bindings: imx908: Add Sony IMX908 sensor Lachlan Michael
2026-08-06 7:09 ` [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver Lachlan Michael
0 siblings, 2 replies; 7+ messages in thread
From: Lachlan Michael @ 2026-08-06 7:09 UTC (permalink / raw)
To: mchehab, sakari.ailus, hverkuil+cisco, laurent.pinchart,
linux-media, devicetree
Cc: robh, krzk+dt, conor+dt, kieran.bingham, jai.luthra,
Ryuichi.Tadano, Kengo.Hayasaka, Tim.Bird, Kazumi.A.Sato,
linux-kernel, Lachlan Michael
This series adds device tree bindings and a V4L2 sub-device driver for
the Sony IMX908 image sensor.
The IMX908 is an 8.39 MP (3856x2176) CMOS image sensor with a MIPI CSI-2
output interface. The driver supports RAW10 and RAW12 output formats,
exposure and analogue gain controls, image flipping, blanking controls,
window cropping and test pattern generation.
HDR modes and RAW16 output are not currently supported.
The driver has been tested with libcamera on Raspberry Pi 5 based
hardware.
Changes in v2:
PATCH 1:
- Reword subject to drop the redundant "bindings" suffix.
- Reference video-interfaces.yaml for the endpoint and switch to
unevaluatedProperties, fixing the remote-endpoint check.
- Drop "link-frequencies: true".
- MAINTAINERS: drop the L: line.
- MAINTAINERS: move the driver F: line to patch 2.
PATCH 2:
- Treat the pixel rate as a fixed sensor property (594 MHz, 8 px/clock),
read-only.
- Compute HMAX from both the array and MIPI link floors.
- Express HBLANK in pixels with a step of 8; keep HMAX fixed in crop
mode.
- Drop struct imx908_mode; cache hmax/vmax directly.
- Change the link-frequency table to s64.
- Fix the probe error-unwind ordering.
- Be silent on success (chip ID print is now dev_dbg).
- Drop redundant comments.
- Kconfig: fix a "module will be called" typo.
Link to v1: https://lore.kernel.org/r/20260730021525.166811-1-lachlan.michael@sony.com
Lachlan Michael (2):
media: dt-bindings: imx908: Add Sony IMX908 sensor
media: i2c: Add Sony IMX908 image sensor driver
.../bindings/media/i2c/sony,imx908.yaml | 105 ++
MAINTAINERS | 6 +
drivers/media/i2c/Kconfig | 11 +
drivers/media/i2c/Makefile | 1 +
drivers/media/i2c/imx908.c | 1501 +++++++++++++++++
5 files changed, 1624 insertions(+)
create mode 100644 Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
create mode 100644 drivers/media/i2c/imx908.c
--
2.47.3
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2 1/2] media: dt-bindings: imx908: Add Sony IMX908 sensor
2026-08-06 7:09 [PATCH v2 0/2] Add bindings and driver for Sony IMX908 Lachlan Michael
@ 2026-08-06 7:09 ` Lachlan Michael
2026-08-06 7:20 ` sashiko-bot
2026-08-06 7:09 ` [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver Lachlan Michael
1 sibling, 1 reply; 7+ messages in thread
From: Lachlan Michael @ 2026-08-06 7:09 UTC (permalink / raw)
To: mchehab, sakari.ailus, hverkuil+cisco, laurent.pinchart,
linux-media, devicetree
Cc: robh, krzk+dt, conor+dt, kieran.bingham, jai.luthra,
Ryuichi.Tadano, Kengo.Hayasaka, Tim.Bird, Kazumi.A.Sato,
linux-kernel, Lachlan Michael
The Sony IMX908 is an 8.39 megapixel (3856x2176) CMOS image sensor
with a MIPI CSI-2 output interface, supporting RAW10 and RAW12 output
over 2 or 4 data lanes.
Add device tree bindings for the sensor.
Signed-off-by: Lachlan Michael <lachlan.michael@sony.com>
---
Changes in v2:
- Reword subject to drop the redundant "bindings" suffix.
- Reference video-interfaces.yaml for the endpoint and switch to
unevaluatedProperties, fixing the remote-endpoint check.
- Drop "link-frequencies: true".
- MAINTAINERS: drop the L: line.
- MAINTAINERS: move the driver F: line to patch 2.
---
.../bindings/media/i2c/sony,imx908.yaml | 105 ++++++++++++++++++
MAINTAINERS | 5 +
2 files changed, 110 insertions(+)
create mode 100644 Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
diff --git a/Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml b/Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
new file mode 100644
index 000000000000..885aba692c60
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
@@ -0,0 +1,105 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2026 Sony Semiconductor Solutions
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/sony,imx908.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sony IMX908 CMOS Image Sensor
+
+maintainers:
+ - Lachlan Michael <Lachlan.Michael@sony.com>
+
+description:
+ Sony IMX908 diagonal 6.42 mm (Type 1/2.8) CMOS active pixel type
+ solid-state image sensor with a square pixel array and 8.39 M
+ (3856x2176) pixels, supporting MIPI CSI-2 output with
+ RAW10 and RAW12 formats, configured as either 2 or 4 data lanes.
+ The I2C address is fixed to 0x1A as per sensor data sheet.
+
+properties:
+ compatible:
+ const: sony,imx908
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ description: Input clock (24 MHz, 27 MHz, 37.125 MHz, 72 MHz or 74.25 MHz)
+ maxItems: 1
+
+ dvdd-supply:
+ description: Digital supply voltage (1.1V)
+
+ ovdd-supply:
+ description: Interface supply voltage (1.8V)
+
+ avdd-supply:
+ description: Analog supply voltage (3.3V)
+
+ reset-gpios:
+ description: Sensor reset (XCLR) GPIO. Active low.
+ maxItems: 1
+
+ port:
+ $ref: /schemas/graph.yaml#/$defs/port-base
+ unevaluatedProperties: false
+
+ properties:
+ endpoint:
+ $ref: /schemas/media/video-interfaces.yaml#
+ unevaluatedProperties: false
+
+ properties:
+ data-lanes:
+ oneOf:
+ - items:
+ - const: 1
+ - const: 2
+ - items:
+ - const: 1
+ - const: 2
+ - const: 3
+ - const: 4
+
+ required:
+ - data-lanes
+ - link-frequencies
+
+required:
+ - compatible
+ - reg
+ - clocks
+ - dvdd-supply
+ - ovdd-supply
+ - avdd-supply
+ - port
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ camera@1a {
+ compatible = "sony,imx908";
+ reg = <0x1a>;
+ clocks = <&cdce913_cam0 0>;
+ dvdd-supply = <&cam_dvdd_1r1v>;
+ ovdd-supply = <&cam_ovdd_1r8v>;
+ avdd-supply = <&cam_avdd_3r3v>;
+ reset-gpios = <&tca6416_cam0 5 GPIO_ACTIVE_LOW>;
+
+ port {
+ imx908_out: endpoint {
+ data-lanes = <1 2 3 4>;
+ link-frequencies = /bits/ 64 <720000000>;
+ remote-endpoint = <&csi0_in>;
+ };
+ };
+ };
+ };
+
diff --git a/MAINTAINERS b/MAINTAINERS
index 4b592cf49746..666c90e100f1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25256,6 +25256,11 @@ T: git git://linuxtv.org/media.git
F: Documentation/devicetree/bindings/media/i2c/sony,imx415.yaml
F: drivers/media/i2c/imx415.c
+SONY IMX908 SENSOR DRIVER
+M: Lachlan Michael <lachlan.michael@sony.com>
+S: Maintained
+F: Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
+
SONY MEMORYSTICK SUBSYSTEM
M: Maxim Levitsky <maximlevitsky@gmail.com>
M: Alex Dubov <oakad@yahoo.com>
--
2.47.3
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver
2026-08-06 7:09 [PATCH v2 0/2] Add bindings and driver for Sony IMX908 Lachlan Michael
2026-08-06 7:09 ` [PATCH v2 1/2] media: dt-bindings: imx908: Add Sony IMX908 sensor Lachlan Michael
@ 2026-08-06 7:09 ` Lachlan Michael
2026-08-06 7:26 ` sashiko-bot
` (2 more replies)
1 sibling, 3 replies; 7+ messages in thread
From: Lachlan Michael @ 2026-08-06 7:09 UTC (permalink / raw)
To: mchehab, sakari.ailus, hverkuil+cisco, laurent.pinchart,
linux-media, devicetree
Cc: robh, krzk+dt, conor+dt, kieran.bingham, jai.luthra,
Ryuichi.Tadano, Kengo.Hayasaka, Tim.Bird, Kazumi.A.Sato,
linux-kernel, Lachlan Michael
The Sony IMX908 is an 8.39 megapixel (3856x2176) CMOS image sensor
with a MIPI CSI-2 output interface, configurable as either 2 or 4
data lanes.
Add a V4L2 sub-device driver for the sensor. The driver supports
RAW10 and RAW12 output formats, exposure and analogue gain controls,
horizontal and vertical flipping, horizontal and vertical blanking
controls, window cropping and test pattern generation.
HDR modes and RAW16 output are not currently supported.
Signed-off-by: Lachlan Michael <lachlan.michael@sony.com>
---
Changes in v2:
- Treat the pixel rate as a fixed sensor property (594 MHz, 8 px/clock),
read-only.
- Compute HMAX from both the array and MIPI link floors.
- Express HBLANK in pixels with a step of 8; keep HMAX fixed in crop
mode.
- Drop struct imx908_mode; cache hmax/vmax directly.
- Change the link-frequency table to s64.
- Fix the probe error-unwind ordering.
- Be silent on success (chip ID print is now dev_dbg).
- Drop redundant comments.
- Kconfig: fix a "module will be called" typo.
---
MAINTAINERS | 1 +
drivers/media/i2c/Kconfig | 11 +
drivers/media/i2c/Makefile | 1 +
drivers/media/i2c/imx908.c | 1501 ++++++++++++++++++++++++++++++++++++
4 files changed, 1514 insertions(+)
create mode 100644 drivers/media/i2c/imx908.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 666c90e100f1..cbbcda14d4de 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25260,6 +25260,7 @@ SONY IMX908 SENSOR DRIVER
M: Lachlan Michael <lachlan.michael@sony.com>
S: Maintained
F: Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
+F: drivers/media/i2c/imx908.c
SONY MEMORYSTICK SUBSYSTEM
M: Maxim Levitsky <maximlevitsky@gmail.com>
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 5d173e0ecf42..8b41846ac4e1 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -287,6 +287,17 @@ config VIDEO_IMX415
To compile this driver as a module, choose M here: the
module will be called imx415.
+config VIDEO_IMX908
+ tristate "Sony IMX908 sensor support"
+ depends on GPIOLIB
+ select V4L2_CCI_I2C
+ help
+ This is a Video4Linux2 sensor driver for the Sony
+ IMX908 CMOS image sensor.
+
+ To compile this driver as a module, choose M here: the
+ module will be called imx908.
+
config VIDEO_MAX9271_LIB
tristate
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index e45359efe0e4..3ccf6d29bbfd 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_VIDEO_IMX335) += imx335.o
obj-$(CONFIG_VIDEO_IMX355) += imx355.o
obj-$(CONFIG_VIDEO_IMX412) += imx412.o
obj-$(CONFIG_VIDEO_IMX415) += imx415.o
+obj-$(CONFIG_VIDEO_IMX908) += imx908.o
obj-$(CONFIG_VIDEO_IR_I2C) += ir-kbd-i2c.o
obj-$(CONFIG_VIDEO_ISL7998X) += isl7998x.o
obj-$(CONFIG_VIDEO_KS0127) += ks0127.o
diff --git a/drivers/media/i2c/imx908.c b/drivers/media/i2c/imx908.c
new file mode 100644
index 000000000000..406605330bd9
--- /dev/null
+++ b/drivers/media/i2c/imx908.c
@@ -0,0 +1,1501 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * V4L2 driver for Sony IMX908
+ *
+ * Diagonal 6.42 mm (Type 1/2.8) CMOS image sensor with 8.39 M pixels.
+ *
+ * Copyright 2026 Sony Semiconductor Solutions Corporation
+ *
+ */
+
+#include <linux/align.h>
+#include <linux/array_size.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/container_of.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/math.h> /* DIV_ROUND_UP */
+#include <linux/math64.h> /* DIV64_U64_ROUND_UP */
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+
+#include <media/media-entity.h>
+#include <media/v4l2-cci.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mediabus.h>
+#include <media/v4l2-rect.h>
+#include <media/v4l2-subdev.h>
+
+/* ---- IMX908 Registers --------- */
+#define IMX908_REG_STANDBY CCI_REG8(0x3000)
+#define IMX908_STANDBY_EN BIT(0) /* Standby mode */
+#define IMX908_STANDBY_CANCEL 0x00 /* Operating mode */
+#define IMX908_REG_XMSTA CCI_REG8(0x3002) /* [0] Init 1h */
+#define IMX908_START_CONTROLLER 0x00 /* Controller mode operation start */
+#define IMX908_STOP_CONTROLLER 0x01 /* Controller mode operation stop */
+#define IMX908_REG_XMASTER CCI_REG8(0x3003) /* [0] Init 0h */
+#define IMX908_CONTROLLER_MODE 0x00
+#define IMX908_REG_INCK_SEL CCI_REG8(0x3014) /* 0:74.25 1:37.125 2:72 3:27 4:24 */
+#define IMX908_REG_DATARATE_SEL CCI_REG8(0x3015)
+
+/* ---- Crop */
+#define IMX908_REG_WINMODE CCI_REG8(0x3018) /* [3:0] */
+#define IMX908_WINMODE_ALLPIX 0x00 /* All-pixel readout mode */
+#define IMX908_WINMODE_CROP 0x04 /* Window cropping mode */
+
+/* ---- Flip */
+#define IMX908_REG_HREVERSE CCI_REG8(0x3020) /* 0:Normal, 1:Inverted */
+#define IMX908_REG_VREVERSE CCI_REG8(0x3021) /* 0:Normal, 1:Inverted */
+
+/* ---- Internal Analog to Digital conversion bit width */
+#define IMX908_REG_ADBIT CCI_REG8(0x3022)
+#define IMX908_ADBIT_10BIT 0x00 /* 10-bit */
+#define IMX908_ADBIT_12BIT 0x01 /* 11-bit + digital dither */
+
+#define IMX908_REG_MDBIT CCI_REG8(0x3023)
+#define IMX908_MDBIT_RAW10 0x00
+#define IMX908_MDBIT_RAW12 0x01
+
+/* ---- VMAX Frame length in lines */
+#define IMX908_REG_VMAX CCI_REG24_LE(0x3028) /* [19:0] */
+#define IMX908_VMAX_MAX 0xfffffU
+#define IMX908_VMAX_DEFAULT 2250U
+/*
+ * Window cropping mode restrictions:
+ * VMAX >= PIX_VWIDTH + 70
+ * VMAX >= 1206
+ */
+#define IMX908_VMAX_CROP_MIN_MARGIN 70U
+#define IMX908_VMAX_CROP_MIN_LIMIT 1206U
+
+/* ---- HMAX Line length in clocks */
+#define IMX908_REG_HMAX CCI_REG16_LE(0x302c) /* [15:0] */
+#define IMX908_HMAX_MAX 0xffffU
+#define IMX908_HMAX_DEFAULT 1100U
+
+/* ---- Cropping related */
+#define IMX908_REG_PIX_HST CCI_REG16_LE(0x303c) /* [12:0] Init 0h */
+#define IMX908_REG_PIX_HWIDTH CCI_REG16_LE(0x303e) /* [12:0] Init 0F10h */
+#define IMX908_REG_LANEMODE CCI_REG8(0x3040) /* 1:2-lane, 3:4-lane */
+#define IMX908_REG_PIX_VST CCI_REG16_LE(0x3044) /* [12:0] Init 0h */
+#define IMX908_REG_PIX_VWIDTH CCI_REG16_LE(0x3046) /* [12:0] Init 0884h */
+#define IMX908_CROP_ALIGN_VSTART 4U
+#define IMX908_CROP_ALIGN_VWIDTH 4U
+#define IMX908_CROP_ALIGN_HSTART 4U
+#define IMX908_CROP_ALIGN_HWIDTH 16U
+#define IMX908_CROP_MIN_HEIGHT 1136U
+#define IMX908_CROP_MIN_WIDTH 1040U
+
+/* ---- Shutter */
+#define IMX908_REG_SHR0 CCI_REG24_LE(0x3050) /* [19:0] */
+#define IMX908_MIN_SHR0 7U
+
+/*
+ * Analogue gain control
+ * Range is from 0 to 100 (0dB - 30dB) with 0.3dB step size
+ * Values from 101 to 240 are valid but correspond to additional digital gain
+ * (0.3dB - 42dB) so don't expose it to userspace
+ */
+#define IMX908_REG_GAIN CCI_REG16_LE(0x3070) /* [10:0] */
+#define IMX908_ANA_GAIN_MAX 100
+#define IMX908_ANA_GAIN_MIN 0
+#define IMX908_ANA_GAIN_STEP 1
+#define IMX908_ANA_GAIN_DEFAULT 0
+
+/* ---- XVS/XHS output mode */
+#define IMX908_XXS_DRV CCI_REG8(0x30a6) /* [1:0] XVS_DRV [3:2] XHS_DRV */
+
+#define IMX908_REG_BLKLEVEL CCI_REG16_LE(0x30dc) /* [15:0] black level */
+
+/* ---- Test Pattern Generator (TPG) registers */
+#define IMX908_REG_TPG_EN CCI_REG8(0x30e0)
+#define IMX908_TPG_EN_BIT BIT(0)
+#define IMX908_REG_TPG_PATSEL CCI_REG8(0x30e2) /* [4:0] pattern idx */
+#define IMX908_REG_TESTCLKEN CCI_REG8(0x4900)
+#define IMX908_TESTCLKEN_BIT BIT(3)
+
+#define IMX908_REG_TYPE_ID CCI_REG16_LE(0x4c0c)
+#define IMX908_CHIP_ID 0x038c /* 908 */
+
+/* ---- IMX908 Common Register List ---- */
+static const struct cci_reg_sequence imx908_common_regs[] = {
+ { IMX908_XXS_DRV, IMX908_CONTROLLER_MODE },
+ { CCI_REG8(0x039c), 0x03 },
+ { CCI_REG8(0x3416), 0x20 },
+ { CCI_REG8(0x3417), 0x00 },
+ { CCI_REG8(0x3456), 0xf4 },
+ { CCI_REG8(0x345d), 0x01 },
+ { CCI_REG8(0x3460), 0x00 },
+ { CCI_REG8(0x3461), 0x0b },
+ { CCI_REG8(0x3471), 0x00 },
+ { CCI_REG8(0x3472), 0x23 },
+ { CCI_REG8(0x347b), 0x02 },
+ { CCI_REG8(0x3481), 0x01 },
+ { CCI_REG8(0x380c), 0x00 },
+ { CCI_REG8(0x380f), 0x0c },
+ { CCI_REG8(0x381c), 0x11 },
+ { CCI_REG8(0x3820), 0x22 },
+ { CCI_REG8(0x3824), 0x33 },
+ { CCI_REG8(0x3828), 0x22 },
+ { CCI_REG8(0x382c), 0x33 },
+ { CCI_REG8(0x3830), 0x33 },
+ { CCI_REG8(0x3838), 0x05 },
+ { CCI_REG8(0x383c), 0x07 },
+ { CCI_REG8(0x3840), 0x06 },
+ { CCI_REG8(0x3848), 0x17 },
+ { CCI_REG8(0x384c), 0x0b },
+ { CCI_REG8(0x3850), 0x10 },
+ { CCI_REG8(0x3854), 0x12 },
+ { CCI_REG8(0x385c), 0x20 },
+ { CCI_REG8(0x38c4), 0x64 },
+ { CCI_REG8(0x38c5), 0x64 },
+ { CCI_REG8(0x38c6), 0x64 },
+ { CCI_REG8(0x3c4a), 0x15 },
+ { CCI_REG8(0x3c4c), 0x13 },
+ { CCI_REG8(0x3c4d), 0x13 },
+ { CCI_REG8(0x3c4e), 0x13 },
+ { CCI_REG8(0x3c50), 0x77 },
+ { CCI_REG8(0x3c51), 0x07 },
+ { CCI_REG8(0x3db4), 0x00 },
+ { CCI_REG8(0x4419), 0x06 },
+ { CCI_REG8(0x441c), 0x00 },
+ { CCI_REG8(0x4426), 0x00 },
+ { CCI_REG8(0x4538), 0x20 },
+ { CCI_REG8(0x4539), 0x19 },
+ { CCI_REG8(0x453a), 0x19 },
+ { CCI_REG8(0x453b), 0x19 },
+ { CCI_REG8(0x453c), 0x19 },
+ { CCI_REG8(0x453d), 0x19 },
+ { CCI_REG8(0x453e), 0x19 },
+ { CCI_REG8(0x453f), 0x19 },
+ { CCI_REG8(0x4540), 0x19 },
+ { CCI_REG8(0x4544), 0x11 },
+ { CCI_REG8(0x4545), 0x11 },
+ { CCI_REG8(0x4546), 0x11 },
+ { CCI_REG8(0x463c), 0x20 },
+ { CCI_REG8(0x465e), 0xcf },
+ { CCI_REG8(0x4684), 0x20 },
+ { CCI_REG8(0x46a6), 0xcf },
+ { CCI_REG8(0x46e2), 0xf3 },
+};
+
+static const u32 tuning_regs[] = {
+ CCI_REG8(0x3d78),
+ CCI_REG8(0x3d79),
+ CCI_REG8(0x3d80),
+ CCI_REG8(0x3d81),
+ CCI_REG8(0x3d88),
+ CCI_REG8(0x3d89),
+ CCI_REG8(0x3d90),
+ CCI_REG8(0x3d91),
+};
+
+#define IMX908_EXPOSURE_MIN 1
+#define IMX908_EXPOSURE_STEP 1
+
+/* ---- Speed of internal clock */
+#define IMX908_XHS_HZ 74250000ULL
+
+/* Fixed pixel rate: column ADC reads 8 pixels per 74.25 MHz clock */
+#define IMX908_PIX_PER_CLK 8U
+#define IMX908_PIXEL_RATE (IMX908_XHS_HZ * IMX908_PIX_PER_CLK) /* 594 MHz */
+
+/* ---- Subdev Pads */
+#define IMX908_SOURCE_PAD 0
+
+#define IMX908_DEFAULT_MBUS_CODE MEDIA_BUS_FMT_SRGGB10_1X10
+
+/*
+ * IMX908 total area includes active area height plus
+ * 4 pixels effective pixel ignored area
+ * 10 pixels vertical direction effective OB
+ * 10 pixels OB side ignored area
+ */
+static const struct v4l2_rect imx908_total_area = {
+ .top = 0,
+ .left = 0,
+ .width = 3856,
+ .height = 2200,
+};
+
+static const struct v4l2_rect imx908_active_area = {
+ .top = 0,
+ .left = 0,
+ .width = 3856,
+ .height = 2176,
+};
+
+/* Recommended 4K recording area centered within the active area */
+static const struct v4l2_rect imx908_recording_area = {
+ .top = 8,
+ .left = 8,
+ .width = 3840,
+ .height = 2160,
+};
+
+static const char *const imx908_supply_names[] = {
+ "avdd", /* Analog (3.3V) supply */
+ "dvdd", /* Digital Core (1.1V) supply */
+ "ovdd", /* IF (1.8V) supply */
+};
+
+static const u32 imx908_mbus_codes[] = {
+ MEDIA_BUS_FMT_SRGGB10_1X10, /* RAW10 */
+ MEDIA_BUS_FMT_SRGGB12_1X12, /* RAW12 */
+};
+
+enum {
+ IMX908_LINK_FREQ_297MHZ,
+ IMX908_LINK_FREQ_360MHZ,
+ IMX908_LINK_FREQ_445MHZ,
+ IMX908_LINK_FREQ_594MHZ,
+ IMX908_LINK_FREQ_720MHZ,
+ IMX908_LINK_FREQ_891MHZ,
+ IMX908_LINK_FREQ_1039MHZ,
+ IMX908_LINK_FREQ_1188MHZ,
+};
+
+static const s64 imx908_link_freqs[] = {
+ [IMX908_LINK_FREQ_297MHZ] = 297000000LL,
+ [IMX908_LINK_FREQ_360MHZ] = 360000000LL,
+ [IMX908_LINK_FREQ_445MHZ] = 445000000LL,
+ [IMX908_LINK_FREQ_594MHZ] = 594000000LL,
+ [IMX908_LINK_FREQ_720MHZ] = 720000000LL,
+ [IMX908_LINK_FREQ_891MHZ] = 891000000LL,
+ [IMX908_LINK_FREQ_1039MHZ] = 1039500000LL,
+ [IMX908_LINK_FREQ_1188MHZ] = 1188000000LL,
+};
+
+/* DDR lane_rate (Mbps/lane) = 2 x link_freq (Hz) / 1e6 */
+static const u8 imx908_datarate_sel[] = {
+ [IMX908_LINK_FREQ_297MHZ] = 0x07, /* 594 Mbps */
+ [IMX908_LINK_FREQ_360MHZ] = 0x06, /* 720 Mbps */
+ [IMX908_LINK_FREQ_445MHZ] = 0x05, /* 891 Mbps */
+ [IMX908_LINK_FREQ_594MHZ] = 0x04, /* 1188 Mbps */
+ [IMX908_LINK_FREQ_720MHZ] = 0x03, /* 1440 Mbps */
+ [IMX908_LINK_FREQ_891MHZ] = 0x02, /* 1782 Mbps */
+ [IMX908_LINK_FREQ_1039MHZ] = 0x01, /* 2079 Mbps */
+ [IMX908_LINK_FREQ_1188MHZ] = 0x00, /* 2376 Mbps */
+};
+
+/* Allowed clock values in Hz */
+static const u32 imx908_inck_table[] = {
+ 74250000,
+ 37125000,
+ 72000000,
+ 27000000,
+ 24000000,
+};
+
+struct imx908 {
+ struct v4l2_subdev sd;
+ struct media_pad pad;
+ struct device *dev;
+
+ struct regmap *cci;
+
+ struct clk *xclk;
+ struct gpio_desc *reset_gpio;
+ struct regulator_bulk_data supplies[ARRAY_SIZE(imx908_supply_names)];
+
+ u8 inck_sel;
+
+ u8 num_lanes;
+ unsigned long link_freq_bitmap;
+ unsigned int link_freq_idx;
+
+ /* Cached current sensor timing */
+ u16 hmax; /* clocks per line */
+ u32 vmax; /* lines per frame */
+
+ struct {
+ struct v4l2_ctrl_handler handler;
+
+ struct v4l2_ctrl *pixel_rate; /* fixed, read-only */
+ struct v4l2_ctrl *exposure;
+ struct v4l2_ctrl *vblank;
+ struct v4l2_ctrl *hblank;
+ struct v4l2_ctrl *test_pattern;
+ } ctrls;
+};
+
+static inline struct imx908 *to_imx908(struct v4l2_subdev *_sd)
+{
+ return container_of(_sd, struct imx908, sd);
+}
+
+/* ----------------------- Basic Helper Functions --------------------------- */
+
+static int imx908_link_freq_to_datarate_sel(struct imx908 *imx,
+ u64 link_freq_hz, u8 *sel)
+{
+ for (unsigned int i = 0; i < ARRAY_SIZE(imx908_link_freqs); i++) {
+ if (imx908_link_freqs[i] == link_freq_hz) {
+ *sel = imx908_datarate_sel[i];
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+static bool imx908_mbus_code_supported(struct imx908 *imx, u32 code)
+{
+ for (unsigned int i = 0; i < ARRAY_SIZE(imx908_mbus_codes); i++) {
+ if (imx908_mbus_codes[i] == code)
+ return true;
+ }
+
+ return false;
+}
+
+static u16 imx908_calc_hmax(u32 width, u32 hblank)
+{
+ /* Fixed pixel rate makes this a divide-by-8 */
+ u32 hmax = DIV_ROUND_UP(width + hblank, IMX908_PIX_PER_CLK);
+
+ return min_t(u32, hmax, IMX908_HMAX_MAX);
+}
+
+static u32 imx908_calc_vmax(u32 height, u32 vblank)
+{
+ return min_t(u32, height + vblank, IMX908_VMAX_MAX);
+}
+
+/*
+ * Array (producer) floor: with the fixed pixel rate the column ADC emits
+ * IMX908_PIX_PER_CLK pixels per internal clock, so a line cannot be shorter
+ * than ceil(width / 8) internal clocks.
+ */
+static u32 imx908_calc_array_min_hmax(u32 width)
+{
+ return DIV_ROUND_UP(width, IMX908_PIX_PER_CLK);
+}
+
+/*
+ * Link (consumer) floor: the line period must be long enough for the MIPI
+ * burst (width * bpp bits) to drain over num_lanes * link_freq * 2 (DDR).
+ */
+static u32 imx908_calc_link_min_hmax(struct imx908 *imx, u32 width, u8 bpp)
+{
+ u64 link_hz = imx908_link_freqs[imx->link_freq_idx];
+ u64 num = (u64)width * bpp * IMX908_XHS_HZ;
+ u64 den = (u64)imx->num_lanes * link_hz * 2; /* DDR */
+
+ /*
+ * den can exceed 32 bits (e.g. 4 lanes * 720 MHz * 2 = 5.76 GHz), so
+ * DIV_ROUND_UP_ULL / do_div would truncate the divisor to u32. Use a
+ * full 64/64 division.
+ */
+ return DIV64_U64_ROUND_UP(num, den);
+}
+
+/* HMAX must satisfy both the array (producer) and link (consumer) limits */
+static u16 imx908_calc_min_hmax(struct imx908 *imx, u32 width, u8 bpp)
+{
+ return max(imx908_calc_array_min_hmax(width),
+ imx908_calc_link_min_hmax(imx, width, bpp));
+}
+
+static u32 imx908_calc_min_vmax(const struct v4l2_rect *crop)
+{
+ /* In window crop mode constrain VMAX (from datasheet) */
+ if (!v4l2_rect_equal(crop, &imx908_active_area))
+ return max_t(u32, crop->height + IMX908_VMAX_CROP_MIN_MARGIN,
+ IMX908_VMAX_CROP_MIN_LIMIT);
+
+ return IMX908_VMAX_DEFAULT;
+}
+
+static u32 imx908_calc_min_vblank(const struct v4l2_rect *crop)
+{
+ u32 min_vmax = imx908_calc_min_vmax(crop);
+
+ if (min_vmax <= crop->height)
+ return 0;
+
+ return min_vmax - crop->height;
+}
+
+static u32 imx908_calc_max_vblank(u32 height)
+{
+ return IMX908_VMAX_MAX - height;
+}
+
+static int imx908_set_exposure_lines(struct imx908 *imx, u32 exposure_lines)
+{
+ u32 max_lines = imx->vmax - IMX908_MIN_SHR0;
+
+ exposure_lines = clamp_t(u32, exposure_lines, 1, max_lines);
+
+ u32 shr0 = imx->vmax - exposure_lines;
+
+ return cci_write(imx->cci, IMX908_REG_SHR0, shr0, NULL);
+}
+
+static u8 imx908_bits_per_pixel(u32 code)
+{
+ switch (code) {
+ case MEDIA_BUS_FMT_SRGGB12_1X12:
+ return 12;
+ case MEDIA_BUS_FMT_SRGGB10_1X10:
+ default:
+ return 10;
+ }
+}
+
+static u32 imx908_hmax_to_hblank(u16 hmax, u32 width)
+{
+ u32 line_len_pixels = hmax * IMX908_PIX_PER_CLK;
+
+ if (line_len_pixels <= width)
+ return 0;
+
+ return line_len_pixels - width;
+}
+
+/*
+ * Window crop: HMAX is fixed to the pre-crop drive mode (datasheet),
+ * so cropping only extends HBLANK. Expose it as a single fixed value to
+ * keep the userspace line time (and thus fps) consistent.
+ */
+static void imx908_update_hblank_crop(struct imx908 *imx, u32 width)
+{
+ u32 hblank = imx908_hmax_to_hblank(imx->hmax, width);
+
+ __v4l2_ctrl_modify_range(imx->ctrls.hblank, hblank, hblank,
+ IMX908_PIX_PER_CLK, hblank);
+
+ if (imx->ctrls.hblank->val != hblank)
+ __v4l2_ctrl_s_ctrl(imx->ctrls.hblank, hblank);
+}
+
+static void imx908_update_hblank_limits(struct imx908 *imx, u32 width, u8 bpp)
+{
+ u16 min_hmax = imx908_calc_min_hmax(imx, width, bpp);
+ u32 min_hblank = imx908_hmax_to_hblank(min_hmax, width);
+ u32 max_hblank = imx908_hmax_to_hblank(IMX908_HMAX_MAX, width);
+ u32 hblank = imx908_hmax_to_hblank(imx->hmax, width);
+
+ hblank = clamp_t(u32, hblank, min_hblank, max_hblank);
+
+ /* step = 8: one HMAX clock == 8 pixels of line length */
+ __v4l2_ctrl_modify_range(imx->ctrls.hblank, min_hblank, max_hblank,
+ IMX908_PIX_PER_CLK, hblank);
+
+ if (imx->ctrls.hblank->val != hblank)
+ __v4l2_ctrl_s_ctrl(imx->ctrls.hblank, hblank);
+}
+
+static void imx908_update_vblank_limits(struct imx908 *imx,
+ const struct v4l2_rect *crop)
+{
+ if (!imx->ctrls.vblank)
+ return;
+
+ u32 min_vblank = imx908_calc_min_vblank(crop);
+ u32 max_vblank = imx908_calc_max_vblank(crop->height);
+
+ __v4l2_ctrl_modify_range(imx->ctrls.vblank, min_vblank, max_vblank, 1,
+ imx->ctrls.vblank->default_value);
+}
+
+/* ------------------ Pattern Generator (TPG) ----------------------- */
+static const char * const imx908_tpg_menu[] = {
+ "Disabled",
+ "All 000h",
+ "All FFFh",
+ "All 555h",
+ "All AAAh",
+ "555h / AAAh Toggle",
+ "AAAh / 555h Toggle",
+ "000h / 555h Toggle",
+ "555h / 000h Toggle",
+ "000h / FFFh Toggle",
+ "FFFh / 000h Toggle",
+ "Horiz Color Bars",
+ "Vert Color Bars",
+};
+
+static int imx908_update_test_pattern(struct imx908 *imx, u32 index)
+{
+ int ret = 0;
+
+ if (index == 0) {
+ /* Picture (not TPG) output setting */
+ cci_update_bits(imx->cci, IMX908_REG_TPG_EN, IMX908_TPG_EN_BIT,
+ 0x00, &ret);
+
+ /* Disable TESTCLKEN (write-only register) */
+ cci_write(imx->cci, IMX908_REG_TESTCLKEN, 0x00, &ret);
+
+ return ret;
+ }
+
+ cci_write(imx->cci, IMX908_REG_TESTCLKEN, IMX908_TESTCLKEN_BIT, &ret);
+ cci_write(imx->cci, IMX908_REG_TPG_PATSEL, index - 1, &ret);
+ cci_update_bits(imx->cci, IMX908_REG_TPG_EN, IMX908_TPG_EN_BIT,
+ IMX908_TPG_EN_BIT, &ret);
+
+ return ret;
+}
+
+/* -------------------- Mode Building ----------------------- */
+static void imx908_mode_build(struct imx908 *imx,
+ const struct v4l2_mbus_framefmt *fmt,
+ const struct v4l2_rect *crop)
+{
+ u8 bpp = imx908_bits_per_pixel(fmt->code);
+
+ /* --- H timing (HMAX) --- */
+ if (v4l2_rect_equal(crop, &imx908_active_area)) {
+ u16 min_hmax = imx908_calc_min_hmax(imx, fmt->width, bpp);
+ u32 min_hblank = imx908_hmax_to_hblank(min_hmax, fmt->width);
+ u32 max_hblank = imx908_hmax_to_hblank(IMX908_HMAX_MAX,
+ fmt->width);
+ u32 hblank = clamp_t(u32, imx->ctrls.hblank->val, min_hblank,
+ max_hblank);
+
+ imx->hmax = imx908_calc_hmax(fmt->width, hblank);
+ } else if (!imx->hmax) {
+ /* First crop before any all-pixel config: seed from default */
+ u32 hblank = imx908_hmax_to_hblank(IMX908_HMAX_DEFAULT,
+ imx908_active_area.width);
+
+ imx->hmax = imx908_calc_hmax(fmt->width, hblank);
+ }
+ /* else: crop with HMAX already fixed by the drive mode - keep it */
+
+ /* --- V timing (VMAX) --- */
+ u32 min_vblank = imx908_calc_min_vblank(crop);
+ u32 max_vblank = imx908_calc_max_vblank(fmt->height);
+ u32 vblank = clamp_t(u32, imx->ctrls.vblank->val,
+ min_vblank, max_vblank);
+
+ imx->vmax = imx908_calc_vmax(fmt->height, vblank);
+}
+
+static void imx908_update_framing_limits(struct imx908 *imx,
+ struct v4l2_subdev_state *state)
+{
+ const struct v4l2_mbus_framefmt *fmt;
+ const struct v4l2_rect *crop;
+
+ fmt = v4l2_subdev_state_get_format(state, IMX908_SOURCE_PAD);
+ crop = v4l2_subdev_state_get_crop(state, IMX908_SOURCE_PAD);
+ u8 bpp = imx908_bits_per_pixel(fmt->code);
+
+ /* All-pixel: HBLANK drives HMAX. Crop: HMAX fixed, HBLANK derived. */
+ if (v4l2_rect_equal(crop, &imx908_active_area))
+ imx908_update_hblank_limits(imx, fmt->width, bpp);
+ else
+ imx908_update_hblank_crop(imx, crop->width);
+
+ imx908_update_vblank_limits(imx, crop);
+ imx908_mode_build(imx, fmt, crop);
+
+ __v4l2_ctrl_modify_range(imx->ctrls.exposure,
+ IMX908_EXPOSURE_MIN,
+ imx->vmax - IMX908_MIN_SHR0,
+ IMX908_EXPOSURE_STEP,
+ imx->ctrls.exposure->default_value);
+}
+
+/* ----------------------- HW Programming ---------------------- */
+
+static int imx908_mode_apply(struct imx908 *imx,
+ const struct v4l2_mbus_framefmt *fmt)
+{
+ int ret = 0;
+ u8 adbit, mdbit;
+
+ switch (fmt->code) {
+ case MEDIA_BUS_FMT_SRGGB12_1X12:
+ adbit = IMX908_ADBIT_12BIT;
+ mdbit = IMX908_MDBIT_RAW12;
+ break;
+
+ case MEDIA_BUS_FMT_SRGGB10_1X10:
+ default:
+ adbit = IMX908_ADBIT_10BIT;
+ mdbit = IMX908_MDBIT_RAW10;
+ break;
+ }
+
+ cci_write(imx->cci, IMX908_REG_XMASTER, IMX908_CONTROLLER_MODE, &ret);
+ cci_write(imx->cci, IMX908_REG_ADBIT, adbit, &ret);
+ cci_write(imx->cci, IMX908_REG_MDBIT, mdbit, &ret);
+
+ /* Tuning registers that need to be changed for RAW10/10-bit */
+ u8 value = adbit == IMX908_ADBIT_10BIT &&
+ mdbit == IMX908_MDBIT_RAW10 ? 0x0c : 0x05;
+
+ for (unsigned int i = 0; i < ARRAY_SIZE(tuning_regs); ++i)
+ cci_write(imx->cci, tuning_regs[i], value, &ret);
+
+ cci_write(imx->cci, IMX908_REG_INCK_SEL, imx->inck_sel, &ret);
+ if (ret) {
+ dev_err(imx->dev, "INCK register write failed: %d\n", ret);
+ return ret;
+ }
+
+ u8 datarate_sel;
+ u64 link_freq = imx908_link_freqs[imx->link_freq_idx];
+
+ ret = imx908_link_freq_to_datarate_sel(imx, link_freq, &datarate_sel);
+ cci_write(imx->cci, IMX908_REG_DATARATE_SEL, datarate_sel, &ret);
+ cci_write(imx->cci, IMX908_REG_LANEMODE, imx->num_lanes - 1, &ret);
+
+ /* Recommended black level offset is 50 in 10-bit, 200 for others */
+ u16 blklevel = (mdbit == IMX908_MDBIT_RAW10) ? 50 : 200;
+
+ cci_write(imx->cci, IMX908_REG_BLKLEVEL, blklevel, &ret);
+
+ return ret;
+}
+
+static int imx908_program_window(struct imx908 *imx,
+ const struct v4l2_rect *crop)
+{
+ bool all_pixel_mode = v4l2_rect_equal(crop, &imx908_active_area);
+ int ret = 0;
+
+ cci_write(imx->cci, IMX908_REG_WINMODE,
+ all_pixel_mode ? IMX908_WINMODE_ALLPIX : IMX908_WINMODE_CROP,
+ &ret);
+
+ if (!all_pixel_mode) {
+ cci_write(imx->cci, IMX908_REG_PIX_HST, crop->left, &ret);
+ cci_write(imx->cci, IMX908_REG_PIX_HWIDTH, crop->width, &ret);
+ cci_write(imx->cci, IMX908_REG_PIX_VST, crop->top, &ret);
+ cci_write(imx->cci, IMX908_REG_PIX_VWIDTH, crop->height, &ret);
+ }
+
+ return ret;
+}
+
+/* ----------------------- Start/Stop streaming ---------------------- */
+
+static int imx908_start_streaming(struct imx908 *imx,
+ struct v4l2_subdev_state *sd_state)
+{
+ const struct v4l2_rect *crop;
+ const struct v4l2_mbus_framefmt *format;
+ int ret = 0;
+
+ crop = v4l2_subdev_state_get_crop(sd_state, IMX908_SOURCE_PAD);
+ format = v4l2_subdev_state_get_format(sd_state, IMX908_SOURCE_PAD);
+
+ imx908_mode_build(imx, format, crop);
+
+ cci_multi_reg_write(imx->cci, imx908_common_regs,
+ ARRAY_SIZE(imx908_common_regs), &ret);
+ if (ret)
+ return ret;
+
+ ret = imx908_mode_apply(imx, format);
+ if (ret)
+ return ret;
+
+ ret = imx908_program_window(imx, crop);
+ if (ret)
+ return ret;
+
+ ret = __v4l2_ctrl_handler_setup(imx->sd.ctrl_handler);
+ if (ret)
+ return ret;
+
+ cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_CANCEL, &ret);
+ msleep(24); /* Datasheet >=24 ms stabilization after standby cancel */
+
+ cci_write(imx->cci, IMX908_REG_XMSTA, IMX908_START_CONTROLLER, &ret);
+ return ret;
+}
+
+static int imx908_stop_streaming(struct imx908 *imx)
+{
+ int ret = 0;
+
+ cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_EN, &ret);
+ cci_write(imx->cci, IMX908_REG_XMSTA, IMX908_STOP_CONTROLLER, &ret);
+ return ret;
+}
+
+/* --------------------------- V4L2 controls ------------------------------ */
+
+static int imx908_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+ struct imx908 *imx = container_of(ctrl->handler, struct imx908,
+ ctrls.handler);
+ struct v4l2_subdev_state *state;
+ const struct v4l2_mbus_framefmt *format;
+ int ret = 0;
+
+ state = v4l2_subdev_get_locked_active_state(&imx->sd);
+ format = v4l2_subdev_state_get_format(state, IMX908_SOURCE_PAD);
+
+ /* Update exposure control limits even if the sensor is not streaming */
+ if (ctrl->id == V4L2_CID_VBLANK) {
+ const struct v4l2_rect *crop;
+
+ crop = v4l2_subdev_state_get_crop(state, IMX908_SOURCE_PAD);
+
+ u32 min_vblank = imx908_calc_min_vblank(crop);
+ u32 max_vblank = imx908_calc_max_vblank(format->height);
+ u32 vblank = clamp_t(u32, ctrl->val, min_vblank, max_vblank);
+
+ imx->vmax = imx908_calc_vmax(format->height, vblank);
+
+ __v4l2_ctrl_modify_range(imx->ctrls.exposure,
+ IMX908_EXPOSURE_MIN,
+ imx->vmax - IMX908_MIN_SHR0,
+ IMX908_EXPOSURE_STEP,
+ imx->ctrls.exposure->default_value);
+ }
+
+ /* Hardware writes only when powered; cached ctrls applied on resume */
+ ret = pm_runtime_get_if_in_use(imx->dev);
+ if (ret <= 0)
+ return ret;
+ ret = 0;
+
+ switch (ctrl->id) {
+ case V4L2_CID_EXPOSURE:
+ ret = imx908_set_exposure_lines(imx, ctrl->val);
+ break;
+
+ case V4L2_CID_ANALOGUE_GAIN:
+ cci_write(imx->cci, IMX908_REG_GAIN, ctrl->val, &ret);
+ break;
+
+ case V4L2_CID_VBLANK:
+ ret = cci_write(imx->cci, IMX908_REG_VMAX, imx->vmax, NULL);
+ /* SHR0 derived from VMAX, re-apply exposure after changes */
+ if (!ret)
+ ret = imx908_set_exposure_lines(imx,
+ imx->ctrls.exposure->val);
+
+ break;
+
+ case V4L2_CID_HBLANK: {
+ const struct v4l2_rect *crop;
+
+ crop = v4l2_subdev_state_get_crop(state, IMX908_SOURCE_PAD);
+
+ /* HBLANK drives HMAX only in all-pixel; crop HMAX is fixed */
+ if (v4l2_rect_equal(crop, &imx908_active_area))
+ imx->hmax = imx908_calc_hmax(format->width, ctrl->val);
+
+ cci_write(imx->cci, IMX908_REG_HMAX, imx->hmax, &ret);
+ break;
+ }
+
+ case V4L2_CID_PIXEL_RATE:
+ case V4L2_CID_LINK_FREQ:
+ break;
+
+ case V4L2_CID_TEST_PATTERN:
+ ret = imx908_update_test_pattern(imx, ctrl->val);
+ break;
+
+ case V4L2_CID_HFLIP:
+ cci_write(imx->cci, IMX908_REG_HREVERSE, ctrl->val, &ret);
+ break;
+
+ case V4L2_CID_VFLIP:
+ cci_write(imx->cci, IMX908_REG_VREVERSE, ctrl->val, &ret);
+ break;
+
+ default:
+ dev_warn(imx->dev,
+ "ctrl(id:0x%x,val:0x%x) is not handled\n",
+ ctrl->id, ctrl->val);
+ break;
+ }
+
+ pm_runtime_put(imx->dev);
+ return ret;
+}
+
+static const struct v4l2_ctrl_ops imx908_ctrl_ops = {
+ .s_ctrl = imx908_set_ctrl,
+};
+
+/* ------------------------ Pad/video ops ------------------ */
+
+static int imx908_enum_mbus_code(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *sd_state,
+ struct v4l2_subdev_mbus_code_enum *code)
+{
+ if (code->index >= ARRAY_SIZE(imx908_mbus_codes))
+ return -EINVAL;
+ code->code = imx908_mbus_codes[code->index];
+ return 0;
+}
+
+static int imx908_enum_frame_size(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *sd_state,
+ struct v4l2_subdev_frame_size_enum *fse)
+{
+ struct imx908 *imx = to_imx908(sd);
+ const struct v4l2_rect *crop;
+
+ if (fse->index > 0)
+ return -EINVAL;
+
+ if (!imx908_mbus_code_supported(imx, fse->code))
+ return -EINVAL;
+
+ crop = v4l2_subdev_state_get_crop(sd_state, IMX908_SOURCE_PAD);
+
+ fse->min_width = crop->width;
+ fse->max_width = crop->width;
+ fse->min_height = crop->height;
+ fse->max_height = crop->height;
+
+ return 0;
+}
+
+static int imx908_set_pad_format(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *sd_state,
+ struct v4l2_subdev_format *fmt)
+{
+ struct imx908 *imx = to_imx908(sd);
+ struct v4l2_mbus_framefmt *format;
+
+ if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE &&
+ v4l2_subdev_is_streaming(sd))
+ return -EBUSY;
+
+ format = v4l2_subdev_state_get_format(sd_state, fmt->pad);
+
+ if (imx908_mbus_code_supported(imx, fmt->format.code))
+ format->code = fmt->format.code;
+ else
+ format->code = IMX908_DEFAULT_MBUS_CODE;
+
+ /* Fully define metadata */
+ format->field = V4L2_FIELD_NONE;
+ format->colorspace = V4L2_COLORSPACE_RAW;
+ format->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
+ format->quantization = V4L2_QUANTIZATION_FULL_RANGE;
+ format->xfer_func = V4L2_XFER_FUNC_NONE;
+
+ /* Limits track the real controls only for the ACTIVE state, not TRY */
+ if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
+ imx908_update_framing_limits(imx, sd_state);
+
+ fmt->format = *format;
+
+ return 0;
+}
+
+static int imx908_set_selection(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *sd_state,
+ struct v4l2_subdev_selection *sel)
+{
+ struct v4l2_mbus_framefmt *format;
+ struct v4l2_rect *crop;
+ struct v4l2_rect *r = &sel->r;
+ struct imx908 *imx = to_imx908(sd);
+
+ if (sel->target != V4L2_SEL_TGT_CROP)
+ return -EINVAL;
+
+ if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE &&
+ v4l2_subdev_is_streaming(sd))
+ return -EBUSY;
+
+ crop = v4l2_subdev_state_get_crop(sd_state, sel->pad);
+ format = v4l2_subdev_state_get_format(sd_state, sel->pad);
+
+ /*
+ * Round the crop rectangle size down to the hardware alignment
+ * constraints, then clamp it to the supported size range.
+ */
+ r->width = clamp_t(s32, ALIGN_DOWN(r->width, IMX908_CROP_ALIGN_HWIDTH),
+ IMX908_CROP_MIN_WIDTH, imx908_active_area.width);
+ r->height = clamp_t(s32, ALIGN_DOWN(r->height, IMX908_CROP_ALIGN_VWIDTH),
+ IMX908_CROP_MIN_HEIGHT, imx908_active_area.height);
+
+ /*
+ * Round and clamp the crop position similarly, with the maximum value
+ * chosen so that the crop rectangle remains fully inside the active
+ * pixel array.
+ */
+ r->left = clamp_t(s32, ALIGN_DOWN(r->left, IMX908_CROP_ALIGN_HSTART), 0,
+ imx908_active_area.width - r->width);
+ r->top = clamp_t(s32, ALIGN_DOWN(r->top, IMX908_CROP_ALIGN_VSTART), 0,
+ imx908_active_area.height - r->height);
+
+ *crop = *r;
+
+ /* IMX908 has no binning, so the output size matches the crop 1:1 */
+ format->width = crop->width;
+ format->height = crop->height;
+
+ if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE)
+ imx908_update_framing_limits(imx, sd_state);
+
+ return 0;
+}
+
+static int imx908_get_selection(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *sd_state,
+ struct v4l2_subdev_selection *sel)
+{
+ switch (sel->target) {
+ case V4L2_SEL_TGT_CROP:
+ sel->r = *v4l2_subdev_state_get_crop(sd_state,
+ IMX908_SOURCE_PAD);
+ return 0;
+
+ case V4L2_SEL_TGT_NATIVE_SIZE:
+ sel->r = imx908_total_area;
+ return 0;
+
+ case V4L2_SEL_TGT_CROP_DEFAULT:
+ sel->r = imx908_recording_area;
+ return 0;
+
+ case V4L2_SEL_TGT_CROP_BOUNDS:
+ sel->r = imx908_active_area;
+ return 0;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int imx908_enable_streams(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *sd_state,
+ u32 pad,
+ u64 streams_mask)
+{
+ struct imx908 *imx = to_imx908(sd);
+ int ret;
+
+ ret = pm_runtime_resume_and_get(imx->dev);
+ if (ret)
+ return ret;
+
+ ret = imx908_start_streaming(imx, sd_state);
+ if (ret) {
+ pm_runtime_mark_last_busy(imx->dev);
+ pm_runtime_put_autosuspend(imx->dev);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int imx908_disable_streams(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *sd_state,
+ u32 pad,
+ u64 streams_mask)
+{
+ struct imx908 *imx = to_imx908(sd);
+ int ret;
+
+ ret = imx908_stop_streaming(imx);
+
+ pm_runtime_mark_last_busy(imx->dev);
+ pm_runtime_put_autosuspend(imx->dev);
+
+ return ret;
+}
+
+static int imx908_init_state(struct v4l2_subdev *sd,
+ struct v4l2_subdev_state *sd_state)
+{
+ struct v4l2_subdev_selection sel = {
+ .which = V4L2_SUBDEV_FORMAT_TRY,
+ .pad = IMX908_SOURCE_PAD,
+ .target = V4L2_SEL_TGT_CROP,
+ .r = imx908_active_area,
+ };
+ struct v4l2_subdev_format fmt = {
+ .which = V4L2_SUBDEV_FORMAT_TRY,
+ .pad = IMX908_SOURCE_PAD,
+ .format = {
+ .code = IMX908_DEFAULT_MBUS_CODE,
+ .width = imx908_active_area.width,
+ .height = imx908_active_area.height,
+ },
+ };
+
+ imx908_set_selection(sd, sd_state, &sel);
+ imx908_set_pad_format(sd, sd_state, &fmt);
+
+ return 0;
+}
+
+static const struct v4l2_subdev_core_ops imx908_core_ops = {
+ .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
+ .unsubscribe_event = v4l2_event_subdev_unsubscribe,
+};
+
+static const struct v4l2_subdev_video_ops imx908_video_ops = {
+ .s_stream = v4l2_subdev_s_stream_helper,
+};
+
+static const struct v4l2_subdev_pad_ops imx908_pad_ops = {
+ .enum_mbus_code = imx908_enum_mbus_code,
+ .enum_frame_size = imx908_enum_frame_size,
+ .get_fmt = v4l2_subdev_get_fmt,
+ .set_fmt = imx908_set_pad_format,
+ .get_selection = imx908_get_selection,
+ .set_selection = imx908_set_selection,
+ .enable_streams = imx908_enable_streams,
+ .disable_streams = imx908_disable_streams,
+};
+
+static const struct v4l2_subdev_internal_ops imx908_internal_ops = {
+ .init_state = imx908_init_state,
+};
+
+static const struct v4l2_subdev_ops imx908_subdev_ops = {
+ .core = &imx908_core_ops,
+ .video = &imx908_video_ops,
+ .pad = &imx908_pad_ops,
+};
+
+/* ----------------------- Power management ---------------------- */
+
+static int imx908_power_on(struct imx908 *imx)
+{
+ int ret;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(imx908_supply_names),
+ imx->supplies);
+ if (ret) {
+ dev_err(imx->dev, "failed to enable regulators\n");
+ return ret;
+ }
+ msleep(200); /* IMX908 power ok after 200ms */
+
+ if (imx->reset_gpio) {
+ gpiod_set_value_cansleep(imx->reset_gpio, 1); /* XCLR low */
+ udelay(1); /* >= 500ns T_low */
+ gpiod_set_value_cansleep(imx->reset_gpio, 0); /* Sensor start */
+ }
+
+ ret = clk_prepare_enable(imx->xclk);
+ if (ret) {
+ dev_err(imx->dev, "failed to enable xclk: %d\n", ret);
+ goto err_reset;
+ }
+
+ /* T_1 >=20us delay before initial SDA/SCL */
+ usleep_range(20, 25);
+
+ return 0;
+
+err_reset:
+ gpiod_set_value_cansleep(imx->reset_gpio, 1); /* assert reset */
+ regulator_bulk_disable(ARRAY_SIZE(imx908_supply_names), imx->supplies);
+ return ret;
+}
+
+static void imx908_power_off(struct imx908 *imx)
+{
+ gpiod_set_value_cansleep(imx->reset_gpio, 1);
+ clk_disable_unprepare(imx->xclk);
+ regulator_bulk_disable(ARRAY_SIZE(imx908_supply_names), imx->supplies);
+}
+
+static int imx908_runtime_resume(struct device *dev)
+{
+ struct v4l2_subdev *sd = dev_get_drvdata(dev);
+ struct imx908 *imx = to_imx908(sd);
+
+ return imx908_power_on(imx);
+}
+
+static int imx908_runtime_suspend(struct device *dev)
+{
+ struct v4l2_subdev *sd = dev_get_drvdata(dev);
+ struct imx908 *imx = to_imx908(sd);
+
+ imx908_power_off(imx);
+ return 0;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(imx908_pm_ops,
+ imx908_runtime_suspend,
+ imx908_runtime_resume, NULL);
+
+/* ------------------------------- Probe/remove --------------------------- */
+
+static int imx908_get_inck_sel(struct imx908 *imx, u32 xclk_freq)
+{
+ for (unsigned int i = 0; i < ARRAY_SIZE(imx908_inck_table); i++) {
+ if (imx908_inck_table[i] == xclk_freq) {
+ imx->inck_sel = i;
+ return 0;
+ }
+ }
+
+ return dev_err_probe(imx->dev, -EINVAL, "unsupported xclk %u Hz\n",
+ xclk_freq);
+}
+
+static int imx908_get_regulators(struct imx908 *imx)
+{
+ for (unsigned int i = 0; i < ARRAY_SIZE(imx908_supply_names); i++)
+ imx->supplies[i].supply = imx908_supply_names[i];
+
+ return devm_regulator_bulk_get(imx->dev,
+ ARRAY_SIZE(imx908_supply_names),
+ imx->supplies);
+}
+
+static int imx908_parse_fwnode(struct imx908 *imx)
+{
+ struct fwnode_handle *ep;
+ struct v4l2_fwnode_endpoint bus_cfg = {
+ .bus_type = V4L2_MBUS_CSI2_DPHY
+ };
+ int ret = 0;
+
+ ep = fwnode_graph_get_next_endpoint(dev_fwnode(imx->dev), NULL);
+ if (!ep) {
+ dev_err(imx->dev, "failed to find endpoint in device tree\n");
+ return -ENXIO;
+ }
+
+ /* Only data-lanes and link-frequencies are used from the endpoint */
+ ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
+ fwnode_handle_put(ep);
+ if (ret)
+ return ret;
+
+ imx->num_lanes = bus_cfg.bus.mipi_csi2.num_data_lanes;
+
+ if (imx->num_lanes != 2 && imx->num_lanes != 4) {
+ dev_err(imx->dev,
+ "only 2 or 4 CSI-2 data lanes are supported (got %u)\n",
+ imx->num_lanes);
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ ret = v4l2_link_freq_to_bitmap(imx->dev,
+ bus_cfg.link_frequencies,
+ bus_cfg.nr_of_link_frequencies,
+ imx908_link_freqs,
+ ARRAY_SIZE(imx908_link_freqs),
+ &imx->link_freq_bitmap);
+ if (ret) {
+ dev_err(imx->dev, "failed to parse link frequencies from DT\n");
+ goto out_free;
+ }
+
+ if (bitmap_empty(&imx->link_freq_bitmap, ARRAY_SIZE(imx908_link_freqs))) {
+ dev_err(imx->dev,
+ "no common link frequencies between driver and DT\n");
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ imx->link_freq_idx = __ffs(imx->link_freq_bitmap);
+ dev_dbg(imx->dev, "using %u lanes at link freq %llu Hz\n",
+ imx->num_lanes, imx908_link_freqs[imx->link_freq_idx]);
+
+out_free:
+ v4l2_fwnode_endpoint_free(&bus_cfg);
+ return ret;
+}
+
+static int imx908_init_controls(struct imx908 *imx)
+{
+ struct v4l2_ctrl_handler *hdl = &imx->ctrls.handler;
+ struct v4l2_fwnode_device_properties props;
+ struct v4l2_ctrl *link_freq_ctl;
+ int ret;
+
+ ret = v4l2_ctrl_handler_init(hdl, 11);
+ if (ret)
+ return ret;
+
+ imx->ctrls.pixel_rate = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
+ V4L2_CID_PIXEL_RATE,
+ IMX908_PIXEL_RATE,
+ IMX908_PIXEL_RATE, 1,
+ IMX908_PIXEL_RATE);
+ if (imx->ctrls.pixel_rate)
+ imx->ctrls.pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+ link_freq_ctl = v4l2_ctrl_new_int_menu(hdl, &imx908_ctrl_ops,
+ V4L2_CID_LINK_FREQ,
+ ARRAY_SIZE(imx908_link_freqs) - 1,
+ imx->link_freq_idx,
+ imx908_link_freqs);
+
+ if (link_freq_ctl)
+ link_freq_ctl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+ imx->hmax = IMX908_HMAX_DEFAULT;
+ imx->vmax = IMX908_VMAX_DEFAULT;
+
+ u32 min_vblank = IMX908_VMAX_DEFAULT - imx908_active_area.height;
+ u32 max_vblank = imx908_calc_max_vblank(imx908_active_area.height);
+
+ imx->ctrls.vblank = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
+ V4L2_CID_VBLANK,
+ min_vblank,
+ max_vblank,
+ 1,
+ min_vblank);
+
+ u8 bpp = imx908_bits_per_pixel(IMX908_DEFAULT_MBUS_CODE);
+ u16 min_hmax = imx908_calc_min_hmax(imx, imx908_active_area.width, bpp);
+ u32 min_hblank = imx908_hmax_to_hblank(min_hmax,
+ imx908_active_area.width);
+ u32 max_hblank = imx908_hmax_to_hblank(IMX908_HMAX_MAX,
+ imx908_active_area.width);
+ u32 hblank = imx908_hmax_to_hblank(IMX908_HMAX_DEFAULT,
+ imx908_active_area.width);
+
+ /* Default HMAX can be infeasible at low link freqs; clamp into range */
+ hblank = clamp_t(u32, hblank, min_hblank, max_hblank);
+
+ /* Keep cached HMAX consistent with the clamped default */
+ imx->hmax = imx908_calc_hmax(imx908_active_area.width, hblank);
+
+ imx->ctrls.hblank = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
+ V4L2_CID_HBLANK,
+ min_hblank,
+ max_hblank,
+ IMX908_PIX_PER_CLK,
+ hblank);
+ u32 max_exp = IMX908_VMAX_DEFAULT - IMX908_MIN_SHR0;
+
+ imx->ctrls.exposure = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
+ V4L2_CID_EXPOSURE,
+ IMX908_EXPOSURE_MIN,
+ max_exp,
+ IMX908_EXPOSURE_STEP,
+ max_exp / 2);
+
+ v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_ANALOGUE_GAIN,
+ IMX908_ANA_GAIN_MIN, IMX908_ANA_GAIN_MAX,
+ IMX908_ANA_GAIN_STEP, IMX908_ANA_GAIN_DEFAULT);
+
+ /* Set test pattern. Menu (13 entries: Disabled + 12 patterns) */
+ imx->ctrls.test_pattern = v4l2_ctrl_new_std_menu_items(hdl,
+ &imx908_ctrl_ops,
+ V4L2_CID_TEST_PATTERN,
+ ARRAY_SIZE(imx908_tpg_menu) - 1,
+ 0,
+ 0,
+ imx908_tpg_menu);
+ if (imx->ctrls.test_pattern)
+ imx->ctrls.test_pattern->flags |= V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
+
+ v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_HFLIP, 0, 1, 1, 0);
+ v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_VFLIP, 0, 1, 1, 0);
+
+ /* Read rotation and orientation properties from the firmware node */
+ ret = v4l2_fwnode_device_parse(imx->dev, &props);
+ if (ret)
+ goto err_free;
+
+ v4l2_ctrl_new_fwnode_properties(hdl, &imx908_ctrl_ops, &props);
+ if (hdl->error) {
+ ret = hdl->error;
+ goto err_free;
+ }
+
+ imx->sd.ctrl_handler = hdl;
+
+ return 0;
+
+err_free:
+ v4l2_ctrl_handler_free(hdl);
+ return ret;
+}
+
+static int imx908_identify_model(struct imx908 *imx)
+{
+ u16 chip_id;
+ u64 val;
+ int ret;
+
+ /*
+ * The TYPE_ID registers are not accessible after power-up while
+ * the device remains in standby. Exit standby and wait for the
+ * required stabilization period before reading the chip ID.
+ */
+ ret = cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_CANCEL, NULL);
+ if (ret)
+ return ret;
+
+ msleep(24); /* Datasheet: >=24 ms stabilization after standby cancel */
+
+ ret = cci_read(imx->cci, IMX908_REG_TYPE_ID, &val, NULL);
+ if (ret)
+ return ret;
+
+ chip_id = val;
+ dev_dbg(imx->dev, "IMX908 chip ID: 0x%04x\n", chip_id);
+
+ if (chip_id != IMX908_CHIP_ID) {
+ dev_err(imx->dev, "unexpected chip ID 0x%04x (expected 0x%04x)\n",
+ chip_id, IMX908_CHIP_ID);
+ return -ENXIO;
+ }
+
+ /* Set to standby mode */
+ ret = cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_EN, NULL);
+ if (ret) {
+ dev_err(imx->dev, "failed to enter standby state: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int imx908_probe(struct i2c_client *client)
+{
+ struct imx908 *imx;
+ int ret;
+
+ imx = devm_kzalloc(&client->dev, sizeof(*imx), GFP_KERNEL);
+ if (!imx)
+ return -ENOMEM;
+ imx->dev = &client->dev;
+
+ v4l2_i2c_subdev_init(&imx->sd, client, &imx908_subdev_ops);
+ imx->sd.internal_ops = &imx908_internal_ops;
+
+ imx->cci = devm_cci_regmap_init_i2c(client, 16);
+ if (IS_ERR(imx->cci))
+ return dev_err_probe(&client->dev, PTR_ERR(imx->cci),
+ "CCI regmap init failed\n");
+
+ imx->xclk = devm_clk_get(imx->dev, NULL);
+ if (IS_ERR(imx->xclk))
+ return dev_err_probe(imx->dev, PTR_ERR(imx->xclk),
+ "failed to get clock\n");
+
+ ret = imx908_get_inck_sel(imx, clk_get_rate(imx->xclk));
+ if (ret)
+ return ret;
+
+ imx->reset_gpio = devm_gpiod_get_optional(imx->dev, "reset",
+ GPIOD_OUT_HIGH);
+
+ if (IS_ERR(imx->reset_gpio))
+ return dev_err_probe(imx->dev, PTR_ERR(imx->reset_gpio),
+ "failed to get reset gpio\n");
+
+ ret = imx908_get_regulators(imx);
+ if (ret)
+ return dev_err_probe(&client->dev, ret,
+ "failed to get regulators\n");
+
+ ret = imx908_parse_fwnode(imx);
+ if (ret)
+ return dev_err_probe(&client->dev, ret,
+ "device tree parse failed\n");
+
+ ret = imx908_power_on(imx);
+ if (ret)
+ return dev_err_probe(&client->dev, ret, "power-on failed\n");
+
+ ret = imx908_identify_model(imx);
+ if (ret) {
+ dev_err(imx->dev, "failed to identify model: %d\n", ret);
+ goto err_power_off;
+ }
+
+ pm_runtime_set_active(imx->dev);
+ pm_runtime_enable(imx->dev);
+
+ ret = imx908_init_controls(imx);
+ if (ret)
+ goto err_pm_disable;
+
+ imx->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
+ imx->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
+ imx->pad.flags = MEDIA_PAD_FL_SOURCE;
+ ret = media_entity_pads_init(&imx->sd.entity, 1, &imx->pad);
+ if (ret)
+ goto err_hdl;
+
+ /* Share the ctrl handler lock so s_ctrl can access the locked state */
+ imx->sd.state_lock = imx->ctrls.handler.lock;
+
+ ret = v4l2_subdev_init_finalize(&imx->sd);
+ if (ret)
+ goto err_entity;
+
+ pm_runtime_set_autosuspend_delay(imx->dev, 1000);
+ pm_runtime_use_autosuspend(imx->dev);
+ pm_runtime_mark_last_busy(imx->dev);
+
+ ret = v4l2_async_register_subdev_sensor(&imx->sd);
+ if (ret)
+ goto err_subdev;
+
+ return 0;
+
+err_subdev:
+ v4l2_subdev_cleanup(&imx->sd);
+err_entity:
+ media_entity_cleanup(&imx->sd.entity);
+err_hdl:
+ v4l2_ctrl_handler_free(imx->sd.ctrl_handler);
+err_pm_disable:
+ pm_runtime_disable(imx->dev);
+ pm_runtime_set_suspended(imx->dev);
+err_power_off:
+ imx908_power_off(imx);
+
+ return ret;
+}
+
+static void imx908_remove(struct i2c_client *client)
+{
+ struct v4l2_subdev *sd = i2c_get_clientdata(client);
+ struct imx908 *imx = to_imx908(sd);
+
+ v4l2_async_unregister_subdev(sd);
+ v4l2_subdev_cleanup(sd);
+ media_entity_cleanup(&sd->entity);
+ v4l2_ctrl_handler_free(sd->ctrl_handler);
+
+ pm_runtime_disable(imx->dev);
+ if (!pm_runtime_status_suspended(imx->dev))
+ imx908_power_off(imx);
+ pm_runtime_set_suspended(imx->dev);
+}
+
+static const struct of_device_id imx908_of_ids[] = {
+ { .compatible = "sony,imx908" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx908_of_ids);
+
+static struct i2c_driver imx908_i2c_driver = {
+ .driver = {
+ .name = "imx908",
+ .pm = pm_ptr(&imx908_pm_ops),
+ .of_match_table = imx908_of_ids,
+ },
+ .probe = imx908_probe,
+ .remove = imx908_remove,
+};
+module_i2c_driver(imx908_i2c_driver);
+
+MODULE_AUTHOR("Lachlan Michael <Lachlan.Michael@sony.com>");
+MODULE_DESCRIPTION("Sony IMX908 Sensor Driver");
+MODULE_LICENSE("GPL");
--
2.47.3
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] media: dt-bindings: imx908: Add Sony IMX908 sensor
2026-08-06 7:09 ` [PATCH v2 1/2] media: dt-bindings: imx908: Add Sony IMX908 sensor Lachlan Michael
@ 2026-08-06 7:20 ` sashiko-bot
0 siblings, 0 replies; 7+ messages in thread
From: sashiko-bot @ 2026-08-06 7:20 UTC (permalink / raw)
To: Lachlan Michael; +Cc: robh, conor+dt, devicetree, media-ci
Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [Medium] Missing reference to standard video interface devices schema forbids common camera properties.
- [Low] The `port` node does not explicitly require an `endpoint` child node.
- [Low] The fixed I2C address is not properly constrained to 0x1A.
--
--- Patch [1]: [PATCH v2 1/2] media: dt-bindings: imx908: Add Sony IMX908 sensor ---
commit 1a763e011d664f488af190964db4f6527791287a
Author: Lachlan Michael <lachlan.michael@sony.com>
media: dt-bindings: imx908: Add Sony IMX908 sensor
This commit adds device tree bindings for the Sony IMX908 CMOS image sensor.
It defines properties like compatible, reg, clocks, supplies, reset-gpios,
and a port node for CSI-2 output.
> diff --git a/Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml b/Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
> new file mode 100644
> index 0000000000000..885aba692c60d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
> @@ -0,0 +1,105 @@
[ ... ]
> +description:
> + Sony IMX908 diagonal 6.42 mm (Type 1/2.8) CMOS active pixel type
> + solid-state image sensor with a square pixel array and 8.39 M
> + (3856x2176) pixels, supporting MIPI CSI-2 output with
> + RAW10 and RAW12 formats, configured as either 2 or 4 data lanes.
> + The I2C address is fixed to 0x1A as per sensor data sheet.
> +
> +properties:
> + compatible:
> + const: sony,imx908
> +
> + reg:
> + maxItems: 1
[Severity: Low]
Does this allow configuring an incorrect I2C address that will silently pass
validation? Since the description explicitly states the address is fixed to
0x1A, should this enforce it with const: 0x1a instead of just maxItems: 1?
[ ... ]
> + reset-gpios:
> + description: Sensor reset (XCLR) GPIO. Active low.
> + maxItems: 1
> +
> + port:
> + $ref: /schemas/graph.yaml#/$defs/port-base
> + unevaluatedProperties: false
> +
> + properties:
> + endpoint:
[Severity: Low]
Does this allow an empty port node without an endpoint to silently pass
validation? Should the port definition explicitly include a
required: [ endpoint ] rule?
> + $ref: /schemas/media/video-interfaces.yaml#
> + unevaluatedProperties: false
> +
> + properties:
> + data-lanes:
[ ... ]
> + required:
> + - data-lanes
> + - link-frequencies
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - dvdd-supply
> + - ovdd-supply
> + - avdd-supply
> + - port
> +
> +additionalProperties: false
[Severity: Medium]
Will this strict constraint incorrectly reject valid device tree configurations
that include standard camera properties, such as rotation or orientation?
Since video-interface-devices.yaml is not referenced at the root level, it
seems any standard property will be treated as an invalid additional property.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260806070934.21764-1-lachlan.michael@sony.com?part=1
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver
2026-08-06 7:09 ` [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver Lachlan Michael
@ 2026-08-06 7:26 ` sashiko-bot
2026-08-06 16:50 ` Dave Stevenson
2026-08-07 6:53 ` Jai Luthra
2 siblings, 0 replies; 7+ messages in thread
From: sashiko-bot @ 2026-08-06 7:26 UTC (permalink / raw)
To: Lachlan Michael; +Cc: devicetree, media-ci, robh, conor+dt
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Setting V4L2 controls fails unconditionally with `-EINVAL` when `CONFIG_PM` is disabled, preventing streaming.
--
--- Patch [2]: [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver ---
commit 92ff772dc92c29c7cb738f917f95440d0e6be72c
Author: Lachlan Michael <lachlan.michael@sony.com>
media: i2c: Add Sony IMX908 image sensor driver
This commit introduces a V4L2 sub-device driver for the Sony IMX908
8.39 megapixel CMOS image sensor. The driver supports RAW10 and RAW12
output formats and configures the MIPI CSI-2 interface.
> diff --git a/drivers/media/i2c/imx908.c b/drivers/media/i2c/imx908.c
> new file mode 100644
> --- /dev/null
> +++ b/drivers/media/i2c/imx908.c
[ ... ]
> @@ -0,0 +1,1501 @@
[ ... ]
> +static int imx908_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
[ ... ]
> + /* Hardware writes only when powered; cached ctrls applied on resume */
> + ret = pm_runtime_get_if_in_use(imx->dev);
> + if (ret <= 0)
> + return ret;
[Severity: Medium]
When the kernel is compiled with CONFIG_PM=n, the inline stub for
pm_runtime_get_if_in_use() returns -EINVAL. Will this cause
imx908_set_ctrl() to unconditionally return -EINVAL in that configuration,
aborting __v4l2_ctrl_handler_setup() and preventing the stream from
starting?
Could this check be adjusted to handle the CONFIG_PM=n case by treating
-EINVAL as success, falling through to access the hardware since it would
be continuously powered in that configuration?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260806070934.21764-1-lachlan.michael@sony.com?part=2
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver
2026-08-06 7:09 ` [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver Lachlan Michael
2026-08-06 7:26 ` sashiko-bot
@ 2026-08-06 16:50 ` Dave Stevenson
2026-08-07 6:53 ` Jai Luthra
2 siblings, 0 replies; 7+ messages in thread
From: Dave Stevenson @ 2026-08-06 16:50 UTC (permalink / raw)
To: Lachlan Michael
Cc: mchehab, sakari.ailus, hverkuil+cisco, laurent.pinchart,
linux-media, devicetree, robh, krzk+dt, conor+dt, kieran.bingham,
jai.luthra, Ryuichi.Tadano, Kengo.Hayasaka, Tim.Bird,
Kazumi.A.Sato, linux-kernel
Hi Lachlan
These comments are made without having access to the datasheet or
software reference manual (I have requested them), so are based on my
experience of other Starvis sensors. Feel free to dismiss them if not
applicable to this sensor.
And some are personal preferences, so feel free to disagree there :-)
On Thu, 6 Aug 2026 at 08:12, Lachlan Michael <lachlan.michael@sony.com> wrote:
>
> The Sony IMX908 is an 8.39 megapixel (3856x2176) CMOS image sensor
> with a MIPI CSI-2 output interface, configurable as either 2 or 4
> data lanes.
>
> Add a V4L2 sub-device driver for the sensor. The driver supports
> RAW10 and RAW12 output formats, exposure and analogue gain controls,
> horizontal and vertical flipping, horizontal and vertical blanking
> controls, window cropping and test pattern generation.
>
> HDR modes and RAW16 output are not currently supported.
>
> Signed-off-by: Lachlan Michael <lachlan.michael@sony.com>
> ---
> Changes in v2:
> - Treat the pixel rate as a fixed sensor property (594 MHz, 8 px/clock),
> read-only.
> - Compute HMAX from both the array and MIPI link floors.
> - Express HBLANK in pixels with a step of 8; keep HMAX fixed in crop
> mode.
> - Drop struct imx908_mode; cache hmax/vmax directly.
> - Change the link-frequency table to s64.
> - Fix the probe error-unwind ordering.
> - Be silent on success (chip ID print is now dev_dbg).
> - Drop redundant comments.
> - Kconfig: fix a "module will be called" typo.
> ---
> MAINTAINERS | 1 +
> drivers/media/i2c/Kconfig | 11 +
> drivers/media/i2c/Makefile | 1 +
> drivers/media/i2c/imx908.c | 1501 ++++++++++++++++++++++++++++++++++++
> 4 files changed, 1514 insertions(+)
> create mode 100644 drivers/media/i2c/imx908.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 666c90e100f1..cbbcda14d4de 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -25260,6 +25260,7 @@ SONY IMX908 SENSOR DRIVER
> M: Lachlan Michael <lachlan.michael@sony.com>
> S: Maintained
> F: Documentation/devicetree/bindings/media/i2c/sony,imx908.yaml
> +F: drivers/media/i2c/imx908.c
>
> SONY MEMORYSTICK SUBSYSTEM
> M: Maxim Levitsky <maximlevitsky@gmail.com>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 5d173e0ecf42..8b41846ac4e1 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -287,6 +287,17 @@ config VIDEO_IMX415
> To compile this driver as a module, choose M here: the
> module will be called imx415.
>
> +config VIDEO_IMX908
> + tristate "Sony IMX908 sensor support"
> + depends on GPIOLIB
> + select V4L2_CCI_I2C
> + help
> + This is a Video4Linux2 sensor driver for the Sony
> + IMX908 CMOS image sensor.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called imx908.
> +
> config VIDEO_MAX9271_LIB
> tristate
>
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index e45359efe0e4..3ccf6d29bbfd 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -61,6 +61,7 @@ obj-$(CONFIG_VIDEO_IMX335) += imx335.o
> obj-$(CONFIG_VIDEO_IMX355) += imx355.o
> obj-$(CONFIG_VIDEO_IMX412) += imx412.o
> obj-$(CONFIG_VIDEO_IMX415) += imx415.o
> +obj-$(CONFIG_VIDEO_IMX908) += imx908.o
> obj-$(CONFIG_VIDEO_IR_I2C) += ir-kbd-i2c.o
> obj-$(CONFIG_VIDEO_ISL7998X) += isl7998x.o
> obj-$(CONFIG_VIDEO_KS0127) += ks0127.o
> diff --git a/drivers/media/i2c/imx908.c b/drivers/media/i2c/imx908.c
> new file mode 100644
> index 000000000000..406605330bd9
> --- /dev/null
> +++ b/drivers/media/i2c/imx908.c
> @@ -0,0 +1,1501 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * V4L2 driver for Sony IMX908
> + *
> + * Diagonal 6.42 mm (Type 1/2.8) CMOS image sensor with 8.39 M pixels.
> + *
> + * Copyright 2026 Sony Semiconductor Solutions Corporation
> + *
> + */
> +
> +#include <linux/align.h>
> +#include <linux/array_size.h>
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/container_of.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/math.h> /* DIV_ROUND_UP */
> +#include <linux/math64.h> /* DIV64_U64_ROUND_UP */
> +#include <linux/minmax.h>
> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/property.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <media/media-entity.h>
> +#include <media/v4l2-cci.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-mediabus.h>
> +#include <media/v4l2-rect.h>
> +#include <media/v4l2-subdev.h>
> +
> +/* ---- IMX908 Registers --------- */
> +#define IMX908_REG_STANDBY CCI_REG8(0x3000)
> +#define IMX908_STANDBY_EN BIT(0) /* Standby mode */
> +#define IMX908_STANDBY_CANCEL 0x00 /* Operating mode */
> +#define IMX908_REG_XMSTA CCI_REG8(0x3002) /* [0] Init 1h */
> +#define IMX908_START_CONTROLLER 0x00 /* Controller mode operation start */
> +#define IMX908_STOP_CONTROLLER 0x01 /* Controller mode operation stop */
> +#define IMX908_REG_XMASTER CCI_REG8(0x3003) /* [0] Init 0h */
> +#define IMX908_CONTROLLER_MODE 0x00
> +#define IMX908_REG_INCK_SEL CCI_REG8(0x3014) /* 0:74.25 1:37.125 2:72 3:27 4:24 */
> +#define IMX908_REG_DATARATE_SEL CCI_REG8(0x3015)
> +
> +/* ---- Crop */
> +#define IMX908_REG_WINMODE CCI_REG8(0x3018) /* [3:0] */
> +#define IMX908_WINMODE_ALLPIX 0x00 /* All-pixel readout mode */
> +#define IMX908_WINMODE_CROP 0x04 /* Window cropping mode */
> +
> +/* ---- Flip */
> +#define IMX908_REG_HREVERSE CCI_REG8(0x3020) /* 0:Normal, 1:Inverted */
> +#define IMX908_REG_VREVERSE CCI_REG8(0x3021) /* 0:Normal, 1:Inverted */
> +
> +/* ---- Internal Analog to Digital conversion bit width */
> +#define IMX908_REG_ADBIT CCI_REG8(0x3022)
> +#define IMX908_ADBIT_10BIT 0x00 /* 10-bit */
> +#define IMX908_ADBIT_12BIT 0x01 /* 11-bit + digital dither */
> +
> +#define IMX908_REG_MDBIT CCI_REG8(0x3023)
> +#define IMX908_MDBIT_RAW10 0x00
> +#define IMX908_MDBIT_RAW12 0x01
> +
> +/* ---- VMAX Frame length in lines */
> +#define IMX908_REG_VMAX CCI_REG24_LE(0x3028) /* [19:0] */
> +#define IMX908_VMAX_MAX 0xfffffU
> +#define IMX908_VMAX_DEFAULT 2250U
> +/*
> + * Window cropping mode restrictions:
> + * VMAX >= PIX_VWIDTH + 70
> + * VMAX >= 1206
> + */
> +#define IMX908_VMAX_CROP_MIN_MARGIN 70U
> +#define IMX908_VMAX_CROP_MIN_LIMIT 1206U
> +
> +/* ---- HMAX Line length in clocks */
> +#define IMX908_REG_HMAX CCI_REG16_LE(0x302c) /* [15:0] */
> +#define IMX908_HMAX_MAX 0xffffU
> +#define IMX908_HMAX_DEFAULT 1100U
> +
> +/* ---- Cropping related */
> +#define IMX908_REG_PIX_HST CCI_REG16_LE(0x303c) /* [12:0] Init 0h */
> +#define IMX908_REG_PIX_HWIDTH CCI_REG16_LE(0x303e) /* [12:0] Init 0F10h */
> +#define IMX908_REG_LANEMODE CCI_REG8(0x3040) /* 1:2-lane, 3:4-lane */
> +#define IMX908_REG_PIX_VST CCI_REG16_LE(0x3044) /* [12:0] Init 0h */
> +#define IMX908_REG_PIX_VWIDTH CCI_REG16_LE(0x3046) /* [12:0] Init 0884h */
> +#define IMX908_CROP_ALIGN_VSTART 4U
> +#define IMX908_CROP_ALIGN_VWIDTH 4U
> +#define IMX908_CROP_ALIGN_HSTART 4U
> +#define IMX908_CROP_ALIGN_HWIDTH 16U
> +#define IMX908_CROP_MIN_HEIGHT 1136U
> +#define IMX908_CROP_MIN_WIDTH 1040U
> +
> +/* ---- Shutter */
> +#define IMX908_REG_SHR0 CCI_REG24_LE(0x3050) /* [19:0] */
> +#define IMX908_MIN_SHR0 7U
> +
> +/*
> + * Analogue gain control
> + * Range is from 0 to 100 (0dB - 30dB) with 0.3dB step size
> + * Values from 101 to 240 are valid but correspond to additional digital gain
> + * (0.3dB - 42dB) so don't expose it to userspace
> + */
> +#define IMX908_REG_GAIN CCI_REG16_LE(0x3070) /* [10:0] */
> +#define IMX908_ANA_GAIN_MAX 100
> +#define IMX908_ANA_GAIN_MIN 0
> +#define IMX908_ANA_GAIN_STEP 1
> +#define IMX908_ANA_GAIN_DEFAULT 0
> +
> +/* ---- XVS/XHS output mode */
> +#define IMX908_XXS_DRV CCI_REG8(0x30a6) /* [1:0] XVS_DRV [3:2] XHS_DRV */
> +
> +#define IMX908_REG_BLKLEVEL CCI_REG16_LE(0x30dc) /* [15:0] black level */
> +
> +/* ---- Test Pattern Generator (TPG) registers */
> +#define IMX908_REG_TPG_EN CCI_REG8(0x30e0)
> +#define IMX908_TPG_EN_BIT BIT(0)
> +#define IMX908_REG_TPG_PATSEL CCI_REG8(0x30e2) /* [4:0] pattern idx */
> +#define IMX908_REG_TESTCLKEN CCI_REG8(0x4900)
> +#define IMX908_TESTCLKEN_BIT BIT(3)
> +
> +#define IMX908_REG_TYPE_ID CCI_REG16_LE(0x4c0c)
> +#define IMX908_CHIP_ID 0x038c /* 908 */
> +
> +/* ---- IMX908 Common Register List ---- */
> +static const struct cci_reg_sequence imx908_common_regs[] = {
> + { IMX908_XXS_DRV, IMX908_CONTROLLER_MODE },
> + { CCI_REG8(0x039c), 0x03 },
> + { CCI_REG8(0x3416), 0x20 },
> + { CCI_REG8(0x3417), 0x00 },
> + { CCI_REG8(0x3456), 0xf4 },
> + { CCI_REG8(0x345d), 0x01 },
> + { CCI_REG8(0x3460), 0x00 },
> + { CCI_REG8(0x3461), 0x0b },
> + { CCI_REG8(0x3471), 0x00 },
> + { CCI_REG8(0x3472), 0x23 },
> + { CCI_REG8(0x347b), 0x02 },
> + { CCI_REG8(0x3481), 0x01 },
> + { CCI_REG8(0x380c), 0x00 },
> + { CCI_REG8(0x380f), 0x0c },
> + { CCI_REG8(0x381c), 0x11 },
> + { CCI_REG8(0x3820), 0x22 },
> + { CCI_REG8(0x3824), 0x33 },
> + { CCI_REG8(0x3828), 0x22 },
> + { CCI_REG8(0x382c), 0x33 },
> + { CCI_REG8(0x3830), 0x33 },
> + { CCI_REG8(0x3838), 0x05 },
> + { CCI_REG8(0x383c), 0x07 },
> + { CCI_REG8(0x3840), 0x06 },
> + { CCI_REG8(0x3848), 0x17 },
> + { CCI_REG8(0x384c), 0x0b },
> + { CCI_REG8(0x3850), 0x10 },
> + { CCI_REG8(0x3854), 0x12 },
> + { CCI_REG8(0x385c), 0x20 },
> + { CCI_REG8(0x38c4), 0x64 },
> + { CCI_REG8(0x38c5), 0x64 },
> + { CCI_REG8(0x38c6), 0x64 },
> + { CCI_REG8(0x3c4a), 0x15 },
> + { CCI_REG8(0x3c4c), 0x13 },
> + { CCI_REG8(0x3c4d), 0x13 },
> + { CCI_REG8(0x3c4e), 0x13 },
> + { CCI_REG8(0x3c50), 0x77 },
> + { CCI_REG8(0x3c51), 0x07 },
> + { CCI_REG8(0x3db4), 0x00 },
> + { CCI_REG8(0x4419), 0x06 },
> + { CCI_REG8(0x441c), 0x00 },
> + { CCI_REG8(0x4426), 0x00 },
> + { CCI_REG8(0x4538), 0x20 },
> + { CCI_REG8(0x4539), 0x19 },
> + { CCI_REG8(0x453a), 0x19 },
> + { CCI_REG8(0x453b), 0x19 },
> + { CCI_REG8(0x453c), 0x19 },
> + { CCI_REG8(0x453d), 0x19 },
> + { CCI_REG8(0x453e), 0x19 },
> + { CCI_REG8(0x453f), 0x19 },
> + { CCI_REG8(0x4540), 0x19 },
> + { CCI_REG8(0x4544), 0x11 },
> + { CCI_REG8(0x4545), 0x11 },
> + { CCI_REG8(0x4546), 0x11 },
> + { CCI_REG8(0x463c), 0x20 },
> + { CCI_REG8(0x465e), 0xcf },
> + { CCI_REG8(0x4684), 0x20 },
> + { CCI_REG8(0x46a6), 0xcf },
> + { CCI_REG8(0x46e2), 0xf3 },
> +};
> +
> +static const u32 tuning_regs[] = {
Rename to bit_depth_regs? That is what they are programmed based on.
Almost all registers affect the tuning.
> + CCI_REG8(0x3d78),
> + CCI_REG8(0x3d79),
> + CCI_REG8(0x3d80),
> + CCI_REG8(0x3d81),
> + CCI_REG8(0x3d88),
> + CCI_REG8(0x3d89),
> + CCI_REG8(0x3d90),
> + CCI_REG8(0x3d91),
> +};
> +
> +#define IMX908_EXPOSURE_MIN 1
> +#define IMX908_EXPOSURE_STEP 1
> +
> +/* ---- Speed of internal clock */
> +#define IMX908_XHS_HZ 74250000ULL
> +
> +/* Fixed pixel rate: column ADC reads 8 pixels per 74.25 MHz clock */
> +#define IMX908_PIX_PER_CLK 8U
> +#define IMX908_PIXEL_RATE (IMX908_XHS_HZ * IMX908_PIX_PER_CLK) /* 594 MHz */
> +
> +/* ---- Subdev Pads */
> +#define IMX908_SOURCE_PAD 0
> +
> +#define IMX908_DEFAULT_MBUS_CODE MEDIA_BUS_FMT_SRGGB10_1X10
> +
> +/*
> + * IMX908 total area includes active area height plus
> + * 4 pixels effective pixel ignored area
> + * 10 pixels vertical direction effective OB
> + * 10 pixels OB side ignored area
> + */
> +static const struct v4l2_rect imx908_total_area = {
> + .top = 0,
> + .left = 0,
> + .width = 3856,
> + .height = 2200,
> +};
> +
> +static const struct v4l2_rect imx908_active_area = {
> + .top = 0,
> + .left = 0,
> + .width = 3856,
> + .height = 2176,
> +};
> +
> +/* Recommended 4K recording area centered within the active area */
> +static const struct v4l2_rect imx908_recording_area = {
> + .top = 8,
> + .left = 8,
> + .width = 3840,
> + .height = 2160,
> +};
> +
> +static const char *const imx908_supply_names[] = {
> + "avdd", /* Analog (3.3V) supply */
> + "dvdd", /* Digital Core (1.1V) supply */
> + "ovdd", /* IF (1.8V) supply */
> +};
> +
> +static const u32 imx908_mbus_codes[] = {
> + MEDIA_BUS_FMT_SRGGB10_1X10, /* RAW10 */
> + MEDIA_BUS_FMT_SRGGB12_1X12, /* RAW12 */
> +};
> +
> +enum {
> + IMX908_LINK_FREQ_297MHZ,
> + IMX908_LINK_FREQ_360MHZ,
> + IMX908_LINK_FREQ_445MHZ,
> + IMX908_LINK_FREQ_594MHZ,
> + IMX908_LINK_FREQ_720MHZ,
> + IMX908_LINK_FREQ_891MHZ,
> + IMX908_LINK_FREQ_1039MHZ,
> + IMX908_LINK_FREQ_1188MHZ,
If you reversed the order in this enum then it would also be the
register value. If you want to be explicit, then assign a value to
each as well
IMX908_LINK_FREQ_1188MHZ = 0x00,
IMX908_LINK_FREQ_1039MHZ = 0x01,
IMX908_LINK_FREQ_891MHZ = 0x02,
etc
That would make imx908_datarate_sel[] and
imx908_link_freq_to_datarate_sel() redundant.
The link frequency control is read only, so it makes no difference to
userspace what order they're in.
> +};
> +
> +static const s64 imx908_link_freqs[] = {
> + [IMX908_LINK_FREQ_297MHZ] = 297000000LL,
> + [IMX908_LINK_FREQ_360MHZ] = 360000000LL,
> + [IMX908_LINK_FREQ_445MHZ] = 445000000LL,
> + [IMX908_LINK_FREQ_594MHZ] = 594000000LL,
> + [IMX908_LINK_FREQ_720MHZ] = 720000000LL,
> + [IMX908_LINK_FREQ_891MHZ] = 891000000LL,
> + [IMX908_LINK_FREQ_1039MHZ] = 1039500000LL,
> + [IMX908_LINK_FREQ_1188MHZ] = 1188000000LL,
> +};
> +
> +/* DDR lane_rate (Mbps/lane) = 2 x link_freq (Hz) / 1e6 */
> +static const u8 imx908_datarate_sel[] = {
> + [IMX908_LINK_FREQ_297MHZ] = 0x07, /* 594 Mbps */
> + [IMX908_LINK_FREQ_360MHZ] = 0x06, /* 720 Mbps */
> + [IMX908_LINK_FREQ_445MHZ] = 0x05, /* 891 Mbps */
> + [IMX908_LINK_FREQ_594MHZ] = 0x04, /* 1188 Mbps */
> + [IMX908_LINK_FREQ_720MHZ] = 0x03, /* 1440 Mbps */
> + [IMX908_LINK_FREQ_891MHZ] = 0x02, /* 1782 Mbps */
> + [IMX908_LINK_FREQ_1039MHZ] = 0x01, /* 2079 Mbps */
> + [IMX908_LINK_FREQ_1188MHZ] = 0x00, /* 2376 Mbps */
> +};
> +
> +/* Allowed clock values in Hz */
> +static const u32 imx908_inck_table[] = {
> + 74250000,
> + 37125000,
> + 72000000,
> + 27000000,
> + 24000000,
> +};
> +
> +struct imx908 {
> + struct v4l2_subdev sd;
> + struct media_pad pad;
> + struct device *dev;
> +
> + struct regmap *cci;
> +
> + struct clk *xclk;
> + struct gpio_desc *reset_gpio;
> + struct regulator_bulk_data supplies[ARRAY_SIZE(imx908_supply_names)];
> +
> + u8 inck_sel;
> +
> + u8 num_lanes;
> + unsigned long link_freq_bitmap;
> + unsigned int link_freq_idx;
> +
> + /* Cached current sensor timing */
> + u16 hmax; /* clocks per line */
> + u32 vmax; /* lines per frame */
> +
> + struct {
> + struct v4l2_ctrl_handler handler;
> +
> + struct v4l2_ctrl *pixel_rate; /* fixed, read-only */
> + struct v4l2_ctrl *exposure;
> + struct v4l2_ctrl *vblank;
> + struct v4l2_ctrl *hblank;
> + struct v4l2_ctrl *test_pattern;
> + } ctrls;
> +};
> +
> +static inline struct imx908 *to_imx908(struct v4l2_subdev *_sd)
> +{
> + return container_of(_sd, struct imx908, sd);
> +}
> +
> +/* ----------------------- Basic Helper Functions --------------------------- */
> +
> +static int imx908_link_freq_to_datarate_sel(struct imx908 *imx,
> + u64 link_freq_hz, u8 *sel)
> +{
> + for (unsigned int i = 0; i < ARRAY_SIZE(imx908_link_freqs); i++) {
> + if (imx908_link_freqs[i] == link_freq_hz) {
> + *sel = imx908_datarate_sel[i];
> + return 0;
> + }
> + }
> + return -EINVAL;
> +}
> +
> +static bool imx908_mbus_code_supported(struct imx908 *imx, u32 code)
> +{
> + for (unsigned int i = 0; i < ARRAY_SIZE(imx908_mbus_codes); i++) {
> + if (imx908_mbus_codes[i] == code)
> + return true;
> + }
> +
> + return false;
> +}
> +
> +static u16 imx908_calc_hmax(u32 width, u32 hblank)
> +{
> + /* Fixed pixel rate makes this a divide-by-8 */
> + u32 hmax = DIV_ROUND_UP(width + hblank, IMX908_PIX_PER_CLK);
> +
> + return min_t(u32, hmax, IMX908_HMAX_MAX);
> +}
> +
> +static u32 imx908_calc_vmax(u32 height, u32 vblank)
> +{
> + return min_t(u32, height + vblank, IMX908_VMAX_MAX);
> +}
> +
> +/*
> + * Array (producer) floor: with the fixed pixel rate the column ADC emits
> + * IMX908_PIX_PER_CLK pixels per internal clock, so a line cannot be shorter
> + * than ceil(width / 8) internal clocks.
> + */
> +static u32 imx908_calc_array_min_hmax(u32 width)
> +{
> + return DIV_ROUND_UP(width, IMX908_PIX_PER_CLK);
> +}
> +
> +/*
> + * Link (consumer) floor: the line period must be long enough for the MIPI
> + * burst (width * bpp bits) to drain over num_lanes * link_freq * 2 (DDR).
> + */
> +static u32 imx908_calc_link_min_hmax(struct imx908 *imx, u32 width, u8 bpp)
> +{
> + u64 link_hz = imx908_link_freqs[imx->link_freq_idx];
> + u64 num = (u64)width * bpp * IMX908_XHS_HZ;
> + u64 den = (u64)imx->num_lanes * link_hz * 2; /* DDR */
> +
> + /*
> + * den can exceed 32 bits (e.g. 4 lanes * 720 MHz * 2 = 5.76 GHz), so
> + * DIV_ROUND_UP_ULL / do_div would truncate the divisor to u32. Use a
> + * full 64/64 division.
> + */
> + return DIV64_U64_ROUND_UP(num, den);
It's unlikely to make that significant a difference, but don't you
need to account for the LP to/from HS transitions on the MIPI link?
> +}
> +
> +/* HMAX must satisfy both the array (producer) and link (consumer) limits */
> +static u16 imx908_calc_min_hmax(struct imx908 *imx, u32 width, u8 bpp)
> +{
> + return max(imx908_calc_array_min_hmax(width),
> + imx908_calc_link_min_hmax(imx, width, bpp));
> +}
> +
> +static u32 imx908_calc_min_vmax(const struct v4l2_rect *crop)
> +{
> + /* In window crop mode constrain VMAX (from datasheet) */
> + if (!v4l2_rect_equal(crop, &imx908_active_area))
> + return max_t(u32, crop->height + IMX908_VMAX_CROP_MIN_MARGIN,
> + IMX908_VMAX_CROP_MIN_LIMIT);
> +
> + return IMX908_VMAX_DEFAULT;
VMAX values in the Starvis datasheets always seem to be "let's give a
nice round frame rate", not "this is the minimum that is valid".
If run in window mode at 3856x2176 then VMAX would be 2176+70 = 2246,
so I guess not such a big difference, but default is not the same as
minimum.
(IMX662 runs quite happily with a margin of 40 which gives an extra
10% on the frame rate compared to the default. I ought to check
against the datasheet for that one though)
> +}
> +
> +static u32 imx908_calc_min_vblank(const struct v4l2_rect *crop)
> +{
> + u32 min_vmax = imx908_calc_min_vmax(crop);
> +
> + if (min_vmax <= crop->height)
> + return 0;
> +
> + return min_vmax - crop->height;
> +}
> +
> +static u32 imx908_calc_max_vblank(u32 height)
> +{
> + return IMX908_VMAX_MAX - height;
> +}
> +
> +static int imx908_set_exposure_lines(struct imx908 *imx, u32 exposure_lines)
> +{
> + u32 max_lines = imx->vmax - IMX908_MIN_SHR0;
> +
> + exposure_lines = clamp_t(u32, exposure_lines, 1, max_lines);
Isn't this clamp already enforced by the control handler limits?
> +
> + u32 shr0 = imx->vmax - exposure_lines;
> +
> + return cci_write(imx->cci, IMX908_REG_SHR0, shr0, NULL);
> +}
> +
> +static u8 imx908_bits_per_pixel(u32 code)
> +{
> + switch (code) {
> + case MEDIA_BUS_FMT_SRGGB12_1X12:
> + return 12;
> + case MEDIA_BUS_FMT_SRGGB10_1X10:
> + default:
> + return 10;
> + }
> +}
> +
> +static u32 imx908_hmax_to_hblank(u16 hmax, u32 width)
> +{
> + u32 line_len_pixels = hmax * IMX908_PIX_PER_CLK;
> +
> + if (line_len_pixels <= width)
> + return 0;
> +
> + return line_len_pixels - width;
> +}
> +
> +/*
> + * Window crop: HMAX is fixed to the pre-crop drive mode (datasheet),
> + * so cropping only extends HBLANK. Expose it as a single fixed value to
> + * keep the userspace line time (and thus fps) consistent.
> + */
> +static void imx908_update_hblank_crop(struct imx908 *imx, u32 width)
> +{
> + u32 hblank = imx908_hmax_to_hblank(imx->hmax, width);
> +
> + __v4l2_ctrl_modify_range(imx->ctrls.hblank, hblank, hblank,
> + IMX908_PIX_PER_CLK, hblank);
> +
> + if (imx->ctrls.hblank->val != hblank)
> + __v4l2_ctrl_s_ctrl(imx->ctrls.hblank, hblank);
> +}
> +
> +static void imx908_update_hblank_limits(struct imx908 *imx, u32 width, u8 bpp)
> +{
> + u16 min_hmax = imx908_calc_min_hmax(imx, width, bpp);
> + u32 min_hblank = imx908_hmax_to_hblank(min_hmax, width);
> + u32 max_hblank = imx908_hmax_to_hblank(IMX908_HMAX_MAX, width);
> + u32 hblank = imx908_hmax_to_hblank(imx->hmax, width);
> +
> + hblank = clamp_t(u32, hblank, min_hblank, max_hblank);
> +
> + /* step = 8: one HMAX clock == 8 pixels of line length */
> + __v4l2_ctrl_modify_range(imx->ctrls.hblank, min_hblank, max_hblank,
> + IMX908_PIX_PER_CLK, hblank);
> +
> + if (imx->ctrls.hblank->val != hblank)
> + __v4l2_ctrl_s_ctrl(imx->ctrls.hblank, hblank);
> +}
> +
> +static void imx908_update_vblank_limits(struct imx908 *imx,
> + const struct v4l2_rect *crop)
> +{
> + if (!imx->ctrls.vblank)
> + return;
Is there actually a path that calls this function before the control
has been created? I can't immediately see one, but I do know they can
hide.
> +
> + u32 min_vblank = imx908_calc_min_vblank(crop);
> + u32 max_vblank = imx908_calc_max_vblank(crop->height);
> +
> + __v4l2_ctrl_modify_range(imx->ctrls.vblank, min_vblank, max_vblank, 1,
> + imx->ctrls.vblank->default_value);
> +}
> +
> +/* ------------------ Pattern Generator (TPG) ----------------------- */
> +static const char * const imx908_tpg_menu[] = {
> + "Disabled",
> + "All 000h",
> + "All FFFh",
> + "All 555h",
> + "All AAAh",
> + "555h / AAAh Toggle",
> + "AAAh / 555h Toggle",
> + "000h / 555h Toggle",
> + "555h / 000h Toggle",
> + "000h / FFFh Toggle",
> + "FFFh / 000h Toggle",
> + "Horiz Color Bars",
> + "Vert Color Bars",
> +};
> +
> +static int imx908_update_test_pattern(struct imx908 *imx, u32 index)
> +{
> + int ret = 0;
> +
> + if (index == 0) {
> + /* Picture (not TPG) output setting */
> + cci_update_bits(imx->cci, IMX908_REG_TPG_EN, IMX908_TPG_EN_BIT,
> + 0x00, &ret);
> +
> + /* Disable TESTCLKEN (write-only register) */
> + cci_write(imx->cci, IMX908_REG_TESTCLKEN, 0x00, &ret);
> +
> + return ret;
> + }
> +
> + cci_write(imx->cci, IMX908_REG_TESTCLKEN, IMX908_TESTCLKEN_BIT, &ret);
> + cci_write(imx->cci, IMX908_REG_TPG_PATSEL, index - 1, &ret);
> + cci_update_bits(imx->cci, IMX908_REG_TPG_EN, IMX908_TPG_EN_BIT,
> + IMX908_TPG_EN_BIT, &ret);
> +
> + return ret;
> +}
> +
> +/* -------------------- Mode Building ----------------------- */
> +static void imx908_mode_build(struct imx908 *imx,
> + const struct v4l2_mbus_framefmt *fmt,
> + const struct v4l2_rect *crop)
> +{
> + u8 bpp = imx908_bits_per_pixel(fmt->code);
> +
> + /* --- H timing (HMAX) --- */
> + if (v4l2_rect_equal(crop, &imx908_active_area)) {
> + u16 min_hmax = imx908_calc_min_hmax(imx, fmt->width, bpp);
> + u32 min_hblank = imx908_hmax_to_hblank(min_hmax, fmt->width);
> + u32 max_hblank = imx908_hmax_to_hblank(IMX908_HMAX_MAX,
> + fmt->width);
> + u32 hblank = clamp_t(u32, imx->ctrls.hblank->val, min_hblank,
> + max_hblank);
Again, isn't this clamp enforced by the control handler?
> + imx->hmax = imx908_calc_hmax(fmt->width, hblank);
> + } else if (!imx->hmax) {
> + /* First crop before any all-pixel config: seed from default */
> + u32 hblank = imx908_hmax_to_hblank(IMX908_HMAX_DEFAULT,
> + imx908_active_area.width);
> +
> + imx->hmax = imx908_calc_hmax(fmt->width, hblank);
> + }
> + /* else: crop with HMAX already fixed by the drive mode - keep it */
> +
> + /* --- V timing (VMAX) --- */
> + u32 min_vblank = imx908_calc_min_vblank(crop);
General query over defining variables in the middle of functions as
you'll get some reviewers pushing back on it[0].
In this case you're only using the values once each, so there's little
need for them at all.
[0] https://lore.kernel.org/linux-media/alfj3XIkX-2O5BGp@rdacayan/
> + u32 max_vblank = imx908_calc_max_vblank(fmt->height);
> + u32 vblank = clamp_t(u32, imx->ctrls.vblank->val,
> + min_vblank, max_vblank);
> +
> + imx->vmax = imx908_calc_vmax(fmt->height, vblank);
> +}
> +
> +static void imx908_update_framing_limits(struct imx908 *imx,
> + struct v4l2_subdev_state *state)
> +{
> + const struct v4l2_mbus_framefmt *fmt;
> + const struct v4l2_rect *crop;
> +
> + fmt = v4l2_subdev_state_get_format(state, IMX908_SOURCE_PAD);
> + crop = v4l2_subdev_state_get_crop(state, IMX908_SOURCE_PAD);
> + u8 bpp = imx908_bits_per_pixel(fmt->code);
> +
> + /* All-pixel: HBLANK drives HMAX. Crop: HMAX fixed, HBLANK derived. */
> + if (v4l2_rect_equal(crop, &imx908_active_area))
> + imx908_update_hblank_limits(imx, fmt->width, bpp);
> + else
> + imx908_update_hblank_crop(imx, crop->width);
> +
> + imx908_update_vblank_limits(imx, crop);
> + imx908_mode_build(imx, fmt, crop);
> +
> + __v4l2_ctrl_modify_range(imx->ctrls.exposure,
> + IMX908_EXPOSURE_MIN,
> + imx->vmax - IMX908_MIN_SHR0,
> + IMX908_EXPOSURE_STEP,
> + imx->ctrls.exposure->default_value);
> +}
> +
> +/* ----------------------- HW Programming ---------------------- */
> +
> +static int imx908_mode_apply(struct imx908 *imx,
> + const struct v4l2_mbus_framefmt *fmt)
> +{
> + int ret = 0;
> + u8 adbit, mdbit;
> +
> + switch (fmt->code) {
> + case MEDIA_BUS_FMT_SRGGB12_1X12:
> + adbit = IMX908_ADBIT_12BIT;
> + mdbit = IMX908_MDBIT_RAW12;
> + break;
> +
> + case MEDIA_BUS_FMT_SRGGB10_1X10:
> + default:
> + adbit = IMX908_ADBIT_10BIT;
> + mdbit = IMX908_MDBIT_RAW10;
> + break;
> + }
> +
> + cci_write(imx->cci, IMX908_REG_XMASTER, IMX908_CONTROLLER_MODE, &ret);
> + cci_write(imx->cci, IMX908_REG_ADBIT, adbit, &ret);
> + cci_write(imx->cci, IMX908_REG_MDBIT, mdbit, &ret);
> +
> + /* Tuning registers that need to be changed for RAW10/10-bit */
> + u8 value = adbit == IMX908_ADBIT_10BIT &&
> + mdbit == IMX908_MDBIT_RAW10 ? 0x0c : 0x05;
It's impossible for only one of those conditionals to be true as
they're set above.
Set "value" from the switch/case above to put it all in one place.
> +
> + for (unsigned int i = 0; i < ARRAY_SIZE(tuning_regs); ++i)
> + cci_write(imx->cci, tuning_regs[i], value, &ret);
> +
> + cci_write(imx->cci, IMX908_REG_INCK_SEL, imx->inck_sel, &ret);
> + if (ret) {
> + dev_err(imx->dev, "INCK register write failed: %d\n", ret);
> + return ret;
> + }
> +
> + u8 datarate_sel;
> + u64 link_freq = imx908_link_freqs[imx->link_freq_idx];
> +
> + ret = imx908_link_freq_to_datarate_sel(imx, link_freq, &datarate_sel);
Is it possible for this call to fail? Probe has filtered the link
frequencies using v4l2_link_freq_to_bitmap(), so the value has to
match one of the entries.
(Then again I've proposed removing imx908_link_freq_to_datarate_sel() above).
> + cci_write(imx->cci, IMX908_REG_DATARATE_SEL, datarate_sel, &ret);
> + cci_write(imx->cci, IMX908_REG_LANEMODE, imx->num_lanes - 1, &ret);
> +
> + /* Recommended black level offset is 50 in 10-bit, 200 for others */
> + u16 blklevel = (mdbit == IMX908_MDBIT_RAW10) ? 50 : 200;
Move this assignment into the switch/case too.
> +
> + cci_write(imx->cci, IMX908_REG_BLKLEVEL, blklevel, &ret);
> +
> + return ret;
> +}
> +
> +static int imx908_program_window(struct imx908 *imx,
> + const struct v4l2_rect *crop)
> +{
> + bool all_pixel_mode = v4l2_rect_equal(crop, &imx908_active_area);
> + int ret = 0;
> +
> + cci_write(imx->cci, IMX908_REG_WINMODE,
> + all_pixel_mode ? IMX908_WINMODE_ALLPIX : IMX908_WINMODE_CROP,
> + &ret);
This one knocks on to several other checks of the active_area / all-pixel mode.
Why switch into the pre-defined all-pixel mode at all? What advantage
does it give you over always using window mode?
To my mind it just gives the possibility that the crop defined in the
structure is incorrect, therefore you aren't getting the pixels you
thought you were.
(I learned the hard way working on IMX675).
> +
> + if (!all_pixel_mode) {
> + cci_write(imx->cci, IMX908_REG_PIX_HST, crop->left, &ret);
> + cci_write(imx->cci, IMX908_REG_PIX_HWIDTH, crop->width, &ret);
> + cci_write(imx->cci, IMX908_REG_PIX_VST, crop->top, &ret);
> + cci_write(imx->cci, IMX908_REG_PIX_VWIDTH, crop->height, &ret);
> + }
> +
> + return ret;
> +}
> +
> +/* ----------------------- Start/Stop streaming ---------------------- */
> +
> +static int imx908_start_streaming(struct imx908 *imx,
> + struct v4l2_subdev_state *sd_state)
> +{
> + const struct v4l2_rect *crop;
> + const struct v4l2_mbus_framefmt *format;
> + int ret = 0;
> +
> + crop = v4l2_subdev_state_get_crop(sd_state, IMX908_SOURCE_PAD);
> + format = v4l2_subdev_state_get_format(sd_state, IMX908_SOURCE_PAD);
> +
> + imx908_mode_build(imx, format, crop);
> +
> + cci_multi_reg_write(imx->cci, imx908_common_regs,
> + ARRAY_SIZE(imx908_common_regs), &ret);
> + if (ret)
> + return ret;
> +
> + ret = imx908_mode_apply(imx, format);
> + if (ret)
> + return ret;
> +
> + ret = imx908_program_window(imx, crop);
> + if (ret)
> + return ret;
> +
> + ret = __v4l2_ctrl_handler_setup(imx->sd.ctrl_handler);
> + if (ret)
> + return ret;
> +
> + cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_CANCEL, &ret);
> + msleep(24); /* Datasheet >=24 ms stabilization after standby cancel */
> +
> + cci_write(imx->cci, IMX908_REG_XMSTA, IMX908_START_CONTROLLER, &ret);
> + return ret;
> +}
> +
> +static int imx908_stop_streaming(struct imx908 *imx)
> +{
> + int ret = 0;
> +
> + cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_EN, &ret);
> + cci_write(imx->cci, IMX908_REG_XMSTA, IMX908_STOP_CONTROLLER, &ret);
> + return ret;
> +}
> +
> +/* --------------------------- V4L2 controls ------------------------------ */
> +
> +static int imx908_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct imx908 *imx = container_of(ctrl->handler, struct imx908,
> + ctrls.handler);
> + struct v4l2_subdev_state *state;
> + const struct v4l2_mbus_framefmt *format;
> + int ret = 0;
> +
> + state = v4l2_subdev_get_locked_active_state(&imx->sd);
> + format = v4l2_subdev_state_get_format(state, IMX908_SOURCE_PAD);
> +
> + /* Update exposure control limits even if the sensor is not streaming */
> + if (ctrl->id == V4L2_CID_VBLANK) {
> + const struct v4l2_rect *crop;
> +
> + crop = v4l2_subdev_state_get_crop(state, IMX908_SOURCE_PAD);
> +
> + u32 min_vblank = imx908_calc_min_vblank(crop);
> + u32 max_vblank = imx908_calc_max_vblank(format->height);
> + u32 vblank = clamp_t(u32, ctrl->val, min_vblank, max_vblank);
> +
> + imx->vmax = imx908_calc_vmax(format->height, vblank);
> +
> + __v4l2_ctrl_modify_range(imx->ctrls.exposure,
> + IMX908_EXPOSURE_MIN,
> + imx->vmax - IMX908_MIN_SHR0,
> + IMX908_EXPOSURE_STEP,
> + imx->ctrls.exposure->default_value);
> + }
> +
> + /* Hardware writes only when powered; cached ctrls applied on resume */
> + ret = pm_runtime_get_if_in_use(imx->dev);
> + if (ret <= 0)
> + return ret;
> + ret = 0;
> +
> + switch (ctrl->id) {
> + case V4L2_CID_EXPOSURE:
> + ret = imx908_set_exposure_lines(imx, ctrl->val);
> + break;
> +
> + case V4L2_CID_ANALOGUE_GAIN:
> + cci_write(imx->cci, IMX908_REG_GAIN, ctrl->val, &ret);
> + break;
> +
> + case V4L2_CID_VBLANK:
> + ret = cci_write(imx->cci, IMX908_REG_VMAX, imx->vmax, NULL);
> + /* SHR0 derived from VMAX, re-apply exposure after changes */
> + if (!ret)
> + ret = imx908_set_exposure_lines(imx,
> + imx->ctrls.exposure->val);
> +
> + break;
> +
> + case V4L2_CID_HBLANK: {
> + const struct v4l2_rect *crop;
> +
> + crop = v4l2_subdev_state_get_crop(state, IMX908_SOURCE_PAD);
> +
> + /* HBLANK drives HMAX only in all-pixel; crop HMAX is fixed */
> + if (v4l2_rect_equal(crop, &imx908_active_area))
> + imx->hmax = imx908_calc_hmax(format->width, ctrl->val);
> +
> + cci_write(imx->cci, IMX908_REG_HMAX, imx->hmax, &ret);
> + break;
> + }
> +
> + case V4L2_CID_PIXEL_RATE:
> + case V4L2_CID_LINK_FREQ:
> + break;
> +
> + case V4L2_CID_TEST_PATTERN:
> + ret = imx908_update_test_pattern(imx, ctrl->val);
> + break;
> +
> + case V4L2_CID_HFLIP:
> + cci_write(imx->cci, IMX908_REG_HREVERSE, ctrl->val, &ret);
> + break;
> +
> + case V4L2_CID_VFLIP:
> + cci_write(imx->cci, IMX908_REG_VREVERSE, ctrl->val, &ret);
> + break;
> +
> + default:
> + dev_warn(imx->dev,
> + "ctrl(id:0x%x,val:0x%x) is not handled\n",
> + ctrl->id, ctrl->val);
> + break;
> + }
> +
> + pm_runtime_put(imx->dev);
> + return ret;
> +}
> +
> +static const struct v4l2_ctrl_ops imx908_ctrl_ops = {
> + .s_ctrl = imx908_set_ctrl,
> +};
> +
> +/* ------------------------ Pad/video ops ------------------ */
> +
> +static int imx908_enum_mbus_code(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_mbus_code_enum *code)
> +{
> + if (code->index >= ARRAY_SIZE(imx908_mbus_codes))
> + return -EINVAL;
> + code->code = imx908_mbus_codes[code->index];
> + return 0;
> +}
> +
> +static int imx908_enum_frame_size(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_frame_size_enum *fse)
> +{
> + struct imx908 *imx = to_imx908(sd);
> + const struct v4l2_rect *crop;
> +
> + if (fse->index > 0)
> + return -EINVAL;
> +
> + if (!imx908_mbus_code_supported(imx, fse->code))
> + return -EINVAL;
> +
> + crop = v4l2_subdev_state_get_crop(sd_state, IMX908_SOURCE_PAD);
> +
> + fse->min_width = crop->width;
> + fse->max_width = crop->width;
> + fse->min_height = crop->height;
> + fse->max_height = crop->height;
> +
> + return 0;
> +}
> +
> +static int imx908_set_pad_format(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_format *fmt)
> +{
> + struct imx908 *imx = to_imx908(sd);
> + struct v4l2_mbus_framefmt *format;
> +
> + if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE &&
> + v4l2_subdev_is_streaming(sd))
> + return -EBUSY;
> +
> + format = v4l2_subdev_state_get_format(sd_state, fmt->pad);
> +
> + if (imx908_mbus_code_supported(imx, fmt->format.code))
> + format->code = fmt->format.code;
> + else
> + format->code = IMX908_DEFAULT_MBUS_CODE;
> +
> + /* Fully define metadata */
> + format->field = V4L2_FIELD_NONE;
> + format->colorspace = V4L2_COLORSPACE_RAW;
> + format->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> + format->quantization = V4L2_QUANTIZATION_FULL_RANGE;
> + format->xfer_func = V4L2_XFER_FUNC_NONE;
> +
> + /* Limits track the real controls only for the ACTIVE state, not TRY */
> + if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
> + imx908_update_framing_limits(imx, sd_state);
> +
> + fmt->format = *format;
> +
> + return 0;
> +}
> +
> +static int imx908_set_selection(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_selection *sel)
> +{
> + struct v4l2_mbus_framefmt *format;
> + struct v4l2_rect *crop;
> + struct v4l2_rect *r = &sel->r;
> + struct imx908 *imx = to_imx908(sd);
One for the maintainers.
Sakari asked for set_selection to NOT be implemented on imx678 as it
complicates the common raw sensor model conversion [1], and that was
then echoed for imx662 [2] (although that is now hopefully going to be
an extension of imx678).
Is implementing it acceptable here or not?
[1] https://patchwork.linuxtv.org/project/linux-media/patch/20260520-imx678-v3-2-8b5f9676486e@ideasonboard.com/#208147
[2] https://lore.kernel.org/linux-media/al6bO_lg9C9Jgrt0@kekkonen.localdomain/
> +
> + if (sel->target != V4L2_SEL_TGT_CROP)
> + return -EINVAL;
> +
> + if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE &&
> + v4l2_subdev_is_streaming(sd))
> + return -EBUSY;
> +
> + crop = v4l2_subdev_state_get_crop(sd_state, sel->pad);
> + format = v4l2_subdev_state_get_format(sd_state, sel->pad);
> +
> + /*
> + * Round the crop rectangle size down to the hardware alignment
> + * constraints, then clamp it to the supported size range.
> + */
> + r->width = clamp_t(s32, ALIGN_DOWN(r->width, IMX908_CROP_ALIGN_HWIDTH),
> + IMX908_CROP_MIN_WIDTH, imx908_active_area.width);
> + r->height = clamp_t(s32, ALIGN_DOWN(r->height, IMX908_CROP_ALIGN_VWIDTH),
> + IMX908_CROP_MIN_HEIGHT, imx908_active_area.height);
> +
> + /*
> + * Round and clamp the crop position similarly, with the maximum value
> + * chosen so that the crop rectangle remains fully inside the active
> + * pixel array.
> + */
> + r->left = clamp_t(s32, ALIGN_DOWN(r->left, IMX908_CROP_ALIGN_HSTART), 0,
> + imx908_active_area.width - r->width);
> + r->top = clamp_t(s32, ALIGN_DOWN(r->top, IMX908_CROP_ALIGN_VSTART), 0,
> + imx908_active_area.height - r->height);
> +
> + *crop = *r;
> +
> + /* IMX908 has no binning, so the output size matches the crop 1:1 */
> + format->width = crop->width;
> + format->height = crop->height;
> +
> + if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE)
> + imx908_update_framing_limits(imx, sd_state);
> +
> + return 0;
> +}
> +
> +static int imx908_get_selection(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_selection *sel)
> +{
> + switch (sel->target) {
> + case V4L2_SEL_TGT_CROP:
> + sel->r = *v4l2_subdev_state_get_crop(sd_state,
> + IMX908_SOURCE_PAD);
> + return 0;
> +
> + case V4L2_SEL_TGT_NATIVE_SIZE:
> + sel->r = imx908_total_area;
> + return 0;
> +
> + case V4L2_SEL_TGT_CROP_DEFAULT:
> + sel->r = imx908_recording_area;
> + return 0;
> +
> + case V4L2_SEL_TGT_CROP_BOUNDS:
> + sel->r = imx908_active_area;
> + return 0;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int imx908_enable_streams(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + u32 pad,
> + u64 streams_mask)
> +{
> + struct imx908 *imx = to_imx908(sd);
> + int ret;
> +
> + ret = pm_runtime_resume_and_get(imx->dev);
> + if (ret)
> + return ret;
> +
> + ret = imx908_start_streaming(imx, sd_state);
> + if (ret) {
> + pm_runtime_mark_last_busy(imx->dev);
> + pm_runtime_put_autosuspend(imx->dev);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int imx908_disable_streams(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + u32 pad,
> + u64 streams_mask)
> +{
> + struct imx908 *imx = to_imx908(sd);
> + int ret;
> +
> + ret = imx908_stop_streaming(imx);
> +
> + pm_runtime_mark_last_busy(imx->dev);
> + pm_runtime_put_autosuspend(imx->dev);
> +
> + return ret;
> +}
> +
> +static int imx908_init_state(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state)
> +{
> + struct v4l2_subdev_selection sel = {
> + .which = V4L2_SUBDEV_FORMAT_TRY,
> + .pad = IMX908_SOURCE_PAD,
> + .target = V4L2_SEL_TGT_CROP,
> + .r = imx908_active_area,
> + };
> + struct v4l2_subdev_format fmt = {
> + .which = V4L2_SUBDEV_FORMAT_TRY,
> + .pad = IMX908_SOURCE_PAD,
> + .format = {
> + .code = IMX908_DEFAULT_MBUS_CODE,
> + .width = imx908_active_area.width,
> + .height = imx908_active_area.height,
> + },
> + };
> +
> + imx908_set_selection(sd, sd_state, &sel);
> + imx908_set_pad_format(sd, sd_state, &fmt);
> +
> + return 0;
> +}
> +
> +static const struct v4l2_subdev_core_ops imx908_core_ops = {
> + .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
> + .unsubscribe_event = v4l2_event_subdev_unsubscribe,
> +};
> +
> +static const struct v4l2_subdev_video_ops imx908_video_ops = {
> + .s_stream = v4l2_subdev_s_stream_helper,
> +};
> +
> +static const struct v4l2_subdev_pad_ops imx908_pad_ops = {
> + .enum_mbus_code = imx908_enum_mbus_code,
> + .enum_frame_size = imx908_enum_frame_size,
> + .get_fmt = v4l2_subdev_get_fmt,
> + .set_fmt = imx908_set_pad_format,
> + .get_selection = imx908_get_selection,
> + .set_selection = imx908_set_selection,
> + .enable_streams = imx908_enable_streams,
> + .disable_streams = imx908_disable_streams,
> +};
> +
> +static const struct v4l2_subdev_internal_ops imx908_internal_ops = {
> + .init_state = imx908_init_state,
> +};
> +
> +static const struct v4l2_subdev_ops imx908_subdev_ops = {
> + .core = &imx908_core_ops,
> + .video = &imx908_video_ops,
> + .pad = &imx908_pad_ops,
> +};
> +
> +/* ----------------------- Power management ---------------------- */
> +
> +static int imx908_power_on(struct imx908 *imx)
> +{
> + int ret;
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(imx908_supply_names),
> + imx->supplies);
> + if (ret) {
> + dev_err(imx->dev, "failed to enable regulators\n");
> + return ret;
> + }
> + msleep(200); /* IMX908 power ok after 200ms */
Using fsleep() avoids the debate over which delay function is
required. Ditto in various other places.
> +
> + if (imx->reset_gpio) {
> + gpiod_set_value_cansleep(imx->reset_gpio, 1); /* XCLR low */
> + udelay(1); /* >= 500ns T_low */
> + gpiod_set_value_cansleep(imx->reset_gpio, 0); /* Sensor start */
> + }
> +
> + ret = clk_prepare_enable(imx->xclk);
> + if (ret) {
> + dev_err(imx->dev, "failed to enable xclk: %d\n", ret);
> + goto err_reset;
> + }
> +
> + /* T_1 >=20us delay before initial SDA/SCL */
> + usleep_range(20, 25);
> +
> + return 0;
> +
> +err_reset:
> + gpiod_set_value_cansleep(imx->reset_gpio, 1); /* assert reset */
> + regulator_bulk_disable(ARRAY_SIZE(imx908_supply_names), imx->supplies);
> + return ret;
> +}
> +
> +static void imx908_power_off(struct imx908 *imx)
> +{
> + gpiod_set_value_cansleep(imx->reset_gpio, 1);
> + clk_disable_unprepare(imx->xclk);
This may be correct for imx908, but most commonly the power off
sequence is the reverse of power on. This has swapped the order of
clock and reset.
> + regulator_bulk_disable(ARRAY_SIZE(imx908_supply_names), imx->supplies);
> +}
> +
> +static int imx908_runtime_resume(struct device *dev)
> +{
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct imx908 *imx = to_imx908(sd);
> +
> + return imx908_power_on(imx);
> +}
> +
> +static int imx908_runtime_suspend(struct device *dev)
> +{
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct imx908 *imx = to_imx908(sd);
> +
> + imx908_power_off(imx);
> + return 0;
> +}
> +
> +static DEFINE_RUNTIME_DEV_PM_OPS(imx908_pm_ops,
> + imx908_runtime_suspend,
> + imx908_runtime_resume, NULL);
> +
> +/* ------------------------------- Probe/remove --------------------------- */
> +
> +static int imx908_get_inck_sel(struct imx908 *imx, u32 xclk_freq)
> +{
> + for (unsigned int i = 0; i < ARRAY_SIZE(imx908_inck_table); i++) {
> + if (imx908_inck_table[i] == xclk_freq) {
> + imx->inck_sel = i;
> + return 0;
> + }
> + }
> +
> + return dev_err_probe(imx->dev, -EINVAL, "unsupported xclk %u Hz\n",
> + xclk_freq);
> +}
> +
> +static int imx908_get_regulators(struct imx908 *imx)
> +{
> + for (unsigned int i = 0; i < ARRAY_SIZE(imx908_supply_names); i++)
> + imx->supplies[i].supply = imx908_supply_names[i];
> +
> + return devm_regulator_bulk_get(imx->dev,
> + ARRAY_SIZE(imx908_supply_names),
> + imx->supplies);
> +}
> +
> +static int imx908_parse_fwnode(struct imx908 *imx)
> +{
> + struct fwnode_handle *ep;
> + struct v4l2_fwnode_endpoint bus_cfg = {
> + .bus_type = V4L2_MBUS_CSI2_DPHY
> + };
> + int ret = 0;
> +
> + ep = fwnode_graph_get_next_endpoint(dev_fwnode(imx->dev), NULL);
> + if (!ep) {
> + dev_err(imx->dev, "failed to find endpoint in device tree\n");
> + return -ENXIO;
> + }
> +
> + /* Only data-lanes and link-frequencies are used from the endpoint */
> + ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
> + fwnode_handle_put(ep);
> + if (ret)
> + return ret;
> +
> + imx->num_lanes = bus_cfg.bus.mipi_csi2.num_data_lanes;
> +
> + if (imx->num_lanes != 2 && imx->num_lanes != 4) {
> + dev_err(imx->dev,
> + "only 2 or 4 CSI-2 data lanes are supported (got %u)\n",
> + imx->num_lanes);
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + ret = v4l2_link_freq_to_bitmap(imx->dev,
> + bus_cfg.link_frequencies,
> + bus_cfg.nr_of_link_frequencies,
> + imx908_link_freqs,
> + ARRAY_SIZE(imx908_link_freqs),
> + &imx->link_freq_bitmap);
> + if (ret) {
> + dev_err(imx->dev, "failed to parse link frequencies from DT\n");
> + goto out_free;
> + }
> +
> + if (bitmap_empty(&imx->link_freq_bitmap, ARRAY_SIZE(imx908_link_freqs))) {
> + dev_err(imx->dev,
> + "no common link frequencies between driver and DT\n");
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + imx->link_freq_idx = __ffs(imx->link_freq_bitmap);
> + dev_dbg(imx->dev, "using %u lanes at link freq %llu Hz\n",
> + imx->num_lanes, imx908_link_freqs[imx->link_freq_idx]);
> +
> +out_free:
> + v4l2_fwnode_endpoint_free(&bus_cfg);
> + return ret;
> +}
> +
> +static int imx908_init_controls(struct imx908 *imx)
> +{
> + struct v4l2_ctrl_handler *hdl = &imx->ctrls.handler;
> + struct v4l2_fwnode_device_properties props;
> + struct v4l2_ctrl *link_freq_ctl;
> + int ret;
> +
> + ret = v4l2_ctrl_handler_init(hdl, 11);
> + if (ret)
> + return ret;
> +
> + imx->ctrls.pixel_rate = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
> + V4L2_CID_PIXEL_RATE,
> + IMX908_PIXEL_RATE,
> + IMX908_PIXEL_RATE, 1,
> + IMX908_PIXEL_RATE);
> + if (imx->ctrls.pixel_rate)
> + imx->ctrls.pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> + link_freq_ctl = v4l2_ctrl_new_int_menu(hdl, &imx908_ctrl_ops,
> + V4L2_CID_LINK_FREQ,
> + ARRAY_SIZE(imx908_link_freqs) - 1,
> + imx->link_freq_idx,
> + imx908_link_freqs);
> +
> + if (link_freq_ctl)
> + link_freq_ctl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> + imx->hmax = IMX908_HMAX_DEFAULT;
> + imx->vmax = IMX908_VMAX_DEFAULT;
> +
> + u32 min_vblank = IMX908_VMAX_DEFAULT - imx908_active_area.height;
> + u32 max_vblank = imx908_calc_max_vblank(imx908_active_area.height);
> +
> + imx->ctrls.vblank = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
> + V4L2_CID_VBLANK,
> + min_vblank,
> + max_vblank,
> + 1,
> + min_vblank);
> +
> + u8 bpp = imx908_bits_per_pixel(IMX908_DEFAULT_MBUS_CODE);
> + u16 min_hmax = imx908_calc_min_hmax(imx, imx908_active_area.width, bpp);
> + u32 min_hblank = imx908_hmax_to_hblank(min_hmax,
> + imx908_active_area.width);
> + u32 max_hblank = imx908_hmax_to_hblank(IMX908_HMAX_MAX,
> + imx908_active_area.width);
> + u32 hblank = imx908_hmax_to_hblank(IMX908_HMAX_DEFAULT,
> + imx908_active_area.width);
> +
> + /* Default HMAX can be infeasible at low link freqs; clamp into range */
> + hblank = clamp_t(u32, hblank, min_hblank, max_hblank);
> +
> + /* Keep cached HMAX consistent with the clamped default */
> + imx->hmax = imx908_calc_hmax(imx908_active_area.width, hblank);
> +
> + imx->ctrls.hblank = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
> + V4L2_CID_HBLANK,
> + min_hblank,
> + max_hblank,
> + IMX908_PIX_PER_CLK,
> + hblank);
> + u32 max_exp = IMX908_VMAX_DEFAULT - IMX908_MIN_SHR0;
> +
> + imx->ctrls.exposure = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
> + V4L2_CID_EXPOSURE,
> + IMX908_EXPOSURE_MIN,
> + max_exp,
> + IMX908_EXPOSURE_STEP,
> + max_exp / 2);
> +
> + v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_ANALOGUE_GAIN,
> + IMX908_ANA_GAIN_MIN, IMX908_ANA_GAIN_MAX,
> + IMX908_ANA_GAIN_STEP, IMX908_ANA_GAIN_DEFAULT);
> +
> + /* Set test pattern. Menu (13 entries: Disabled + 12 patterns) */
> + imx->ctrls.test_pattern = v4l2_ctrl_new_std_menu_items(hdl,
> + &imx908_ctrl_ops,
> + V4L2_CID_TEST_PATTERN,
> + ARRAY_SIZE(imx908_tpg_menu) - 1,
> + 0,
> + 0,
> + imx908_tpg_menu);
> + if (imx->ctrls.test_pattern)
> + imx->ctrls.test_pattern->flags |= V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
> +
> + v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_HFLIP, 0, 1, 1, 0);
> + v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_VFLIP, 0, 1, 1, 0);
> +
> + /* Read rotation and orientation properties from the firmware node */
> + ret = v4l2_fwnode_device_parse(imx->dev, &props);
> + if (ret)
> + goto err_free;
> +
> + v4l2_ctrl_new_fwnode_properties(hdl, &imx908_ctrl_ops, &props);
> + if (hdl->error) {
> + ret = hdl->error;
> + goto err_free;
> + }
> +
> + imx->sd.ctrl_handler = hdl;
> +
> + return 0;
> +
> +err_free:
> + v4l2_ctrl_handler_free(hdl);
> + return ret;
> +}
> +
> +static int imx908_identify_model(struct imx908 *imx)
> +{
> + u16 chip_id;
> + u64 val;
> + int ret;
> +
> + /*
> + * The TYPE_ID registers are not accessible after power-up while
> + * the device remains in standby. Exit standby and wait for the
> + * required stabilization period before reading the chip ID.
> + */
> + ret = cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_CANCEL, NULL);
> + if (ret)
> + return ret;
> +
> + msleep(24); /* Datasheet: >=24 ms stabilization after standby cancel */
> +
> + ret = cci_read(imx->cci, IMX908_REG_TYPE_ID, &val, NULL);
> + if (ret)
> + return ret;
> +
> + chip_id = val;
> + dev_dbg(imx->dev, "IMX908 chip ID: 0x%04x\n", chip_id);
> +
> + if (chip_id != IMX908_CHIP_ID) {
> + dev_err(imx->dev, "unexpected chip ID 0x%04x (expected 0x%04x)\n",
> + chip_id, IMX908_CHIP_ID);
> + return -ENXIO;
> + }
> +
> + /* Set to standby mode */
> + ret = cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_EN, NULL);
> + if (ret) {
> + dev_err(imx->dev, "failed to enter standby state: %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int imx908_probe(struct i2c_client *client)
> +{
> + struct imx908 *imx;
> + int ret;
> +
> + imx = devm_kzalloc(&client->dev, sizeof(*imx), GFP_KERNEL);
> + if (!imx)
> + return -ENOMEM;
> + imx->dev = &client->dev;
> +
> + v4l2_i2c_subdev_init(&imx->sd, client, &imx908_subdev_ops);
> + imx->sd.internal_ops = &imx908_internal_ops;
> +
> + imx->cci = devm_cci_regmap_init_i2c(client, 16);
> + if (IS_ERR(imx->cci))
> + return dev_err_probe(&client->dev, PTR_ERR(imx->cci),
> + "CCI regmap init failed\n");
> +
> + imx->xclk = devm_clk_get(imx->dev, NULL);
> + if (IS_ERR(imx->xclk))
> + return dev_err_probe(imx->dev, PTR_ERR(imx->xclk),
> + "failed to get clock\n");
> +
> + ret = imx908_get_inck_sel(imx, clk_get_rate(imx->xclk));
> + if (ret)
> + return ret;
> +
> + imx->reset_gpio = devm_gpiod_get_optional(imx->dev, "reset",
> + GPIOD_OUT_HIGH);
> +
> + if (IS_ERR(imx->reset_gpio))
> + return dev_err_probe(imx->dev, PTR_ERR(imx->reset_gpio),
> + "failed to get reset gpio\n");
> +
> + ret = imx908_get_regulators(imx);
> + if (ret)
> + return dev_err_probe(&client->dev, ret,
> + "failed to get regulators\n");
> +
> + ret = imx908_parse_fwnode(imx);
> + if (ret)
> + return dev_err_probe(&client->dev, ret,
> + "device tree parse failed\n");
> +
> + ret = imx908_power_on(imx);
> + if (ret)
> + return dev_err_probe(&client->dev, ret, "power-on failed\n");
> +
> + ret = imx908_identify_model(imx);
> + if (ret) {
> + dev_err(imx->dev, "failed to identify model: %d\n", ret);
> + goto err_power_off;
> + }
> +
> + pm_runtime_set_active(imx->dev);
> + pm_runtime_enable(imx->dev);
> +
> + ret = imx908_init_controls(imx);
> + if (ret)
> + goto err_pm_disable;
> +
> + imx->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
> + imx->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> + imx->pad.flags = MEDIA_PAD_FL_SOURCE;
> + ret = media_entity_pads_init(&imx->sd.entity, 1, &imx->pad);
> + if (ret)
> + goto err_hdl;
> +
> + /* Share the ctrl handler lock so s_ctrl can access the locked state */
> + imx->sd.state_lock = imx->ctrls.handler.lock;
> +
> + ret = v4l2_subdev_init_finalize(&imx->sd);
> + if (ret)
> + goto err_entity;
> +
> + pm_runtime_set_autosuspend_delay(imx->dev, 1000);
> + pm_runtime_use_autosuspend(imx->dev);
Ideally this should be cancelled with
pm_runtime_dont_use_autosuspend() on error or remove.
> + pm_runtime_mark_last_busy(imx->dev);
> +
> + ret = v4l2_async_register_subdev_sensor(&imx->sd);
> + if (ret)
> + goto err_subdev;
I think this has left the sensor powered up. Don't we want a
pm_runtime_idle(imx->dev);
here?
Overall it looks like a pretty clean driver though.
Dave
> +
> + return 0;
> +
> +err_subdev:
> + v4l2_subdev_cleanup(&imx->sd);
> +err_entity:
> + media_entity_cleanup(&imx->sd.entity);
> +err_hdl:
> + v4l2_ctrl_handler_free(imx->sd.ctrl_handler);
> +err_pm_disable:
> + pm_runtime_disable(imx->dev);
> + pm_runtime_set_suspended(imx->dev);
> +err_power_off:
> + imx908_power_off(imx);
> +
> + return ret;
> +}
> +
> +static void imx908_remove(struct i2c_client *client)
> +{
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct imx908 *imx = to_imx908(sd);
> +
> + v4l2_async_unregister_subdev(sd);
> + v4l2_subdev_cleanup(sd);
> + media_entity_cleanup(&sd->entity);
> + v4l2_ctrl_handler_free(sd->ctrl_handler);
> +
> + pm_runtime_disable(imx->dev);
> + if (!pm_runtime_status_suspended(imx->dev))
> + imx908_power_off(imx);
> + pm_runtime_set_suspended(imx->dev);
> +}
> +
> +static const struct of_device_id imx908_of_ids[] = {
> + { .compatible = "sony,imx908" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, imx908_of_ids);
> +
> +static struct i2c_driver imx908_i2c_driver = {
> + .driver = {
> + .name = "imx908",
> + .pm = pm_ptr(&imx908_pm_ops),
> + .of_match_table = imx908_of_ids,
> + },
> + .probe = imx908_probe,
> + .remove = imx908_remove,
> +};
> +module_i2c_driver(imx908_i2c_driver);
> +
> +MODULE_AUTHOR("Lachlan Michael <Lachlan.Michael@sony.com>");
> +MODULE_DESCRIPTION("Sony IMX908 Sensor Driver");
> +MODULE_LICENSE("GPL");
> --
> 2.47.3
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver
2026-08-06 7:09 ` [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver Lachlan Michael
2026-08-06 7:26 ` sashiko-bot
2026-08-06 16:50 ` Dave Stevenson
@ 2026-08-07 6:53 ` Jai Luthra
2 siblings, 0 replies; 7+ messages in thread
From: Jai Luthra @ 2026-08-07 6:53 UTC (permalink / raw)
To: Lachlan Michael, devicetree, hverkuil+cisco, laurent.pinchart,
linux-media, mchehab, sakari.ailus
Cc: robh, krzk+dt, conor+dt, kieran.bingham, Ryuichi.Tadano,
Kengo.Hayasaka, Tim.Bird, Kazumi.A.Sato, linux-kernel,
Lachlan Michael
Hi Lachlan,
Thank you for the patch!
The driver is mostly in good shape, except a few small things and requests
for information that Sony is in the best position to help us with.
Quoting Lachlan Michael (2026-08-06 12:39:34)
> The Sony IMX908 is an 8.39 megapixel (3856x2176) CMOS image sensor
> with a MIPI CSI-2 output interface, configurable as either 2 or 4
> data lanes.
>
> Add a V4L2 sub-device driver for the sensor. The driver supports
> RAW10 and RAW12 output formats, exposure and analogue gain controls,
> horizontal and vertical flipping, horizontal and vertical blanking
> controls, window cropping and test pattern generation.
>
> HDR modes and RAW16 output are not currently supported.
>
> Signed-off-by: Lachlan Michael <lachlan.michael@sony.com>
> ---
> Changes in v2:
> - Treat the pixel rate as a fixed sensor property (594 MHz, 8 px/clock),
> read-only.
> - Compute HMAX from both the array and MIPI link floors.
> - Express HBLANK in pixels with a step of 8; keep HMAX fixed in crop
> mode.
> - Drop struct imx908_mode; cache hmax/vmax directly.
> - Change the link-frequency table to s64.
> - Fix the probe error-unwind ordering.
> - Be silent on success (chip ID print is now dev_dbg).
> - Drop redundant comments.
> - Kconfig: fix a "module will be called" typo.
[...]
> +#define IMX908_EXPOSURE_MIN 1
> +#define IMX908_EXPOSURE_STEP 1
> +
> +/* ---- Speed of internal clock */
> +#define IMX908_XHS_HZ 74250000ULL
> +
> +/* Fixed pixel rate: column ADC reads 8 pixels per 74.25 MHz clock */
> +#define IMX908_PIX_PER_CLK 8U
Can you confirm if the hardware is actually doing this, or this is just a
guess like I had made for IMX678?
It's ideal to know what the hardware does to better calculate minimum HMAX
value for cropped modes for Starvis2/3 sensors in future.
> +#define IMX908_PIXEL_RATE (IMX908_XHS_HZ * IMX908_PIX_PER_CLK) /* 594 MHz */
> +
> +/* ---- Subdev Pads */
> +#define IMX908_SOURCE_PAD 0
> +
> +#define IMX908_DEFAULT_MBUS_CODE MEDIA_BUS_FMT_SRGGB10_1X10
> +
> +/*
> + * IMX908 total area includes active area height plus
> + * 4 pixels effective pixel ignored area
> + * 10 pixels vertical direction effective OB
> + * 10 pixels OB side ignored area
> + */
> +static const struct v4l2_rect imx908_total_area = {
> + .top = 0,
> + .left = 0,
> + .width = 3856,
> + .height = 2200,
> +};
> +
> +static const struct v4l2_rect imx908_active_area = {
> + .top = 0,
> + .left = 0,
> + .width = 3856,
> + .height = 2176,
> +};
> +
> +/* Recommended 4K recording area centered within the active area */
> +static const struct v4l2_rect imx908_recording_area = {
> + .top = 8,
> + .left = 8,
> + .width = 3840,
> + .height = 2160,
If I understand correctly it's better if the sensor captures common
resolutions like 1080p or 2160p with some margin, as some ISPs might need
to discard a few pixels during de-bayer color processing.
Another comment on this below in imx908_get_selection().
[...]
> +struct imx908 {
> + struct v4l2_subdev sd;
> + struct media_pad pad;
> + struct device *dev;
> +
> + struct regmap *cci;
> +
> + struct clk *xclk;
> + struct gpio_desc *reset_gpio;
> + struct regulator_bulk_data supplies[ARRAY_SIZE(imx908_supply_names)];
> +
> + u8 inck_sel;
nit: extra space
> +
> + u8 num_lanes;
> + unsigned long link_freq_bitmap;
> + unsigned int link_freq_idx;
> +
> + /* Cached current sensor timing */
> + u16 hmax; /* clocks per line */
> + u32 vmax; /* lines per frame */
> +
> + struct {
> + struct v4l2_ctrl_handler handler;
> +
> + struct v4l2_ctrl *pixel_rate; /* fixed, read-only */
You can drop this as it is not used by the driver after init.
> + struct v4l2_ctrl *exposure;
> + struct v4l2_ctrl *vblank;
> + struct v4l2_ctrl *hblank;
> + struct v4l2_ctrl *test_pattern;
Same here.
> + } ctrls;
> +};
> +
> +static inline struct imx908 *to_imx908(struct v4l2_subdev *_sd)
> +{
> + return container_of(_sd, struct imx908, sd);
> +}
> +
[...]
> +static u32 imx908_calc_link_min_hmax(struct imx908 *imx, u32 width, u8 bpp)
> +{
> + u64 link_hz = imx908_link_freqs[imx->link_freq_idx];
> + u64 num = (u64)width * bpp * IMX908_XHS_HZ;
> + u64 den = (u64)imx->num_lanes * link_hz * 2; /* DDR */
> +
> + /*
> + * den can exceed 32 bits (e.g. 4 lanes * 720 MHz * 2 = 5.76 GHz), so
> + * DIV_ROUND_UP_ULL / do_div would truncate the divisor to u32. Use a
> + * full 64/64 division.
> + */
> + return DIV64_U64_ROUND_UP(num, den);
Have you tested the lowest values generated here on the sensor? I tend to
agree with Dave's comment on the missing margin, but I don't know enough
about the sensor internals.
It would be helpful if Sony can provide info on the interface between the
pixel array (producer) and MIPI (consumer), if there is a FIFO in between,
and if they have separate PLL clock trees and pixel rates, or use the same
74.25 Mhz clock as your code suggests. And of course what kind of margins
are needed on the blankings.
Does Sony have some internal spreadsheet or tool to figure this out and
populate the recommended values in the "4. Operating Mode" table in the
SRM? We could do the same calculation in the driver directly, this would
help us support free-configuration of crop and HBLANK values for different
usecases.
> +}
> +
[...]
> +/* --------------------------- V4L2 controls ------------------------------ */
> +
> +static int imx908_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct imx908 *imx = container_of(ctrl->handler, struct imx908,
> + ctrls.handler);
> + struct v4l2_subdev_state *state;
> + const struct v4l2_mbus_framefmt *format;
> + int ret = 0;
> +
> + state = v4l2_subdev_get_locked_active_state(&imx->sd);
> + format = v4l2_subdev_state_get_format(state, IMX908_SOURCE_PAD);
> +
> + /* Update exposure control limits even if the sensor is not streaming */
> + if (ctrl->id == V4L2_CID_VBLANK) {
> + const struct v4l2_rect *crop;
> +
> + crop = v4l2_subdev_state_get_crop(state, IMX908_SOURCE_PAD);
> +
> + u32 min_vblank = imx908_calc_min_vblank(crop);
> + u32 max_vblank = imx908_calc_max_vblank(format->height);
> + u32 vblank = clamp_t(u32, ctrl->val, min_vblank, max_vblank);
> +
> + imx->vmax = imx908_calc_vmax(format->height, vblank);
> +
> + __v4l2_ctrl_modify_range(imx->ctrls.exposure,
> + IMX908_EXPOSURE_MIN,
> + imx->vmax - IMX908_MIN_SHR0,
> + IMX908_EXPOSURE_STEP,
> + imx->ctrls.exposure->default_value);
> + }
> +
> + /* Hardware writes only when powered; cached ctrls applied on resume */
> + ret = pm_runtime_get_if_in_use(imx->dev);
> + if (ret <= 0)
This should early return only in the case of ret == 0, as the function
returns negative error code if the PM framework is disabled (CONFIG_PM=n),
in which case we should proceed to update the sensor registers below.
I believe what you did in v1 was correct, but maybe got misled by the LLM
bot? I have opened a bug report for it:
https://github.com/sashiko-dev/sashiko/issues/396
> + return ret;
> + ret = 0;
> +
> + switch (ctrl->id) {
> + case V4L2_CID_EXPOSURE:
> + ret = imx908_set_exposure_lines(imx, ctrl->val);
> + break;
> +
> + case V4L2_CID_ANALOGUE_GAIN:
> + cci_write(imx->cci, IMX908_REG_GAIN, ctrl->val, &ret);
> + break;
> +
> + case V4L2_CID_VBLANK:
> + ret = cci_write(imx->cci, IMX908_REG_VMAX, imx->vmax, NULL);
> + /* SHR0 derived from VMAX, re-apply exposure after changes */
> + if (!ret)
> + ret = imx908_set_exposure_lines(imx,
> + imx->ctrls.exposure->val);
> +
> + break;
> +
> + case V4L2_CID_HBLANK: {
> + const struct v4l2_rect *crop;
> +
> + crop = v4l2_subdev_state_get_crop(state, IMX908_SOURCE_PAD);
> +
> + /* HBLANK drives HMAX only in all-pixel; crop HMAX is fixed */
> + if (v4l2_rect_equal(crop, &imx908_active_area))
> + imx->hmax = imx908_calc_hmax(format->width, ctrl->val);
> +
> + cci_write(imx->cci, IMX908_REG_HMAX, imx->hmax, &ret);
> + break;
> + }
> +
> + case V4L2_CID_PIXEL_RATE:
> + case V4L2_CID_LINK_FREQ:
> + break;
> +
You can drop the above block. RO controls should never reach here.
> + case V4L2_CID_TEST_PATTERN:
> + ret = imx908_update_test_pattern(imx, ctrl->val);
> + break;
> +
> + case V4L2_CID_HFLIP:
> + cci_write(imx->cci, IMX908_REG_HREVERSE, ctrl->val, &ret);
> + break;
> +
> + case V4L2_CID_VFLIP:
> + cci_write(imx->cci, IMX908_REG_VREVERSE, ctrl->val, &ret);
> + break;
> +
> + default:
> + dev_warn(imx->dev,
> + "ctrl(id:0x%x,val:0x%x) is not handled\n",
> + ctrl->id, ctrl->val);
> + break;
> + }
> +
> + pm_runtime_put(imx->dev);
> + return ret;
> +}
> +
[...]
> +static int imx908_get_selection(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_selection *sel)
> +{
> + switch (sel->target) {
> + case V4L2_SEL_TGT_CROP:
> + sel->r = *v4l2_subdev_state_get_crop(sd_state,
> + IMX908_SOURCE_PAD);
> + return 0;
> +
> + case V4L2_SEL_TGT_NATIVE_SIZE:
> + sel->r = imx908_total_area;
> + return 0;
> +
> + case V4L2_SEL_TGT_CROP_DEFAULT:
> + sel->r = imx908_recording_area;
> + return 0;
Kernel doc "8.1.1 Selection targets" for V4L2_SEL_TGT_CROP_DEFAULT:
Suggested cropping rectangle that covers the “whole picture”. This
includes only active pixels and excludes other non-active pixels such
as black pixels.
I believe this means CROP_DEFAULT should include the active non-black
pixels that are supposed to be used as a margin.
In init_state() the driver configures the rectangle to imx908_active_area,
which is the correct thing to do.
Maybe you can drop imx908_recording_area altogether?
> +
> + case V4L2_SEL_TGT_CROP_BOUNDS:
> + sel->r = imx908_active_area;
> + return 0;
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int imx908_enable_streams(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + u32 pad,
> + u64 streams_mask)
> +{
> + struct imx908 *imx = to_imx908(sd);
> + int ret;
> +
> + ret = pm_runtime_resume_and_get(imx->dev);
> + if (ret)
> + return ret;
> +
> + ret = imx908_start_streaming(imx, sd_state);
> + if (ret) {
> + pm_runtime_mark_last_busy(imx->dev);
Drop.
pm_runtime_put_autosuspend() calls pm_runtime_mark_last_busy() for you.
> + pm_runtime_put_autosuspend(imx->dev);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int imx908_disable_streams(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + u32 pad,
> + u64 streams_mask)
> +{
> + struct imx908 *imx = to_imx908(sd);
> + int ret;
> +
> + ret = imx908_stop_streaming(imx);
> +
> + pm_runtime_mark_last_busy(imx->dev);
Same here and anywehere else.
> + pm_runtime_put_autosuspend(imx->dev);
> +
> + return ret;
> +}
> +
> +static int imx908_init_state(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state)
> +{
> + struct v4l2_subdev_selection sel = {
> + .which = V4L2_SUBDEV_FORMAT_TRY,
> + .pad = IMX908_SOURCE_PAD,
> + .target = V4L2_SEL_TGT_CROP,
> + .r = imx908_active_area,
> + };
> + struct v4l2_subdev_format fmt = {
> + .which = V4L2_SUBDEV_FORMAT_TRY,
> + .pad = IMX908_SOURCE_PAD,
> + .format = {
> + .code = IMX908_DEFAULT_MBUS_CODE,
> + .width = imx908_active_area.width,
> + .height = imx908_active_area.height,
> + },
> + };
> +
> + imx908_set_selection(sd, sd_state, &sel);
> + imx908_set_pad_format(sd, sd_state, &fmt);
> +
> + return 0;
> +}
> +
> +static const struct v4l2_subdev_core_ops imx908_core_ops = {
> + .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
> + .unsubscribe_event = v4l2_event_subdev_unsubscribe,
> +};
Drop.
See 17971a430ff9 ("media: i2c: Drop HAS_EVENTS and event handlers")
> +
> +static const struct v4l2_subdev_video_ops imx908_video_ops = {
> + .s_stream = v4l2_subdev_s_stream_helper,
> +};
> +
> +static const struct v4l2_subdev_pad_ops imx908_pad_ops = {
> + .enum_mbus_code = imx908_enum_mbus_code,
> + .enum_frame_size = imx908_enum_frame_size,
> + .get_fmt = v4l2_subdev_get_fmt,
> + .set_fmt = imx908_set_pad_format,
> + .get_selection = imx908_get_selection,
> + .set_selection = imx908_set_selection,
> + .enable_streams = imx908_enable_streams,
> + .disable_streams = imx908_disable_streams,
> +};
> +
> +static const struct v4l2_subdev_internal_ops imx908_internal_ops = {
> + .init_state = imx908_init_state,
> +};
> +
> +static const struct v4l2_subdev_ops imx908_subdev_ops = {
> + .core = &imx908_core_ops,
> + .video = &imx908_video_ops,
> + .pad = &imx908_pad_ops,
> +};
> +
> +/* ----------------------- Power management ---------------------- */
> +
> +static int imx908_power_on(struct imx908 *imx)
> +{
> + int ret;
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(imx908_supply_names),
> + imx->supplies);
> + if (ret) {
> + dev_err(imx->dev, "failed to enable regulators\n");
> + return ret;
> + }
> + msleep(200); /* IMX908 power ok after 200ms */
If there is a required delay for stabilization after the power supplies
come up, that delay is usually modeled as `startup-delay-us = <200000>` in
the device tree node for the regulator(s) so that regulator_bulk_enable()
includes it.
> +
> + if (imx->reset_gpio) {
Not needed as the below function handles optional GPIOs.
> + gpiod_set_value_cansleep(imx->reset_gpio, 1); /* XCLR low */
Drop, the reset is asserted because it was initialized as GPIOD_OUT_HIGH.
> + udelay(1); /* >= 500ns T_low */
> + gpiod_set_value_cansleep(imx->reset_gpio, 0); /* Sensor start */
> + }
> +
> + ret = clk_prepare_enable(imx->xclk);
> + if (ret) {
> + dev_err(imx->dev, "failed to enable xclk: %d\n", ret);
> + goto err_reset;
> + }
> +
> + /* T_1 >=20us delay before initial SDA/SCL */
> + usleep_range(20, 25);
> +
> + return 0;
> +
> +err_reset:
> + gpiod_set_value_cansleep(imx->reset_gpio, 1); /* assert reset */
> + regulator_bulk_disable(ARRAY_SIZE(imx908_supply_names), imx->supplies);
> + return ret;
> +}
> +
[...]
> +static int imx908_parse_fwnode(struct imx908 *imx)
> +{
> + struct fwnode_handle *ep;
> + struct v4l2_fwnode_endpoint bus_cfg = {
> + .bus_type = V4L2_MBUS_CSI2_DPHY
> + };
> + int ret = 0;
> +
> + ep = fwnode_graph_get_next_endpoint(dev_fwnode(imx->dev), NULL);
> + if (!ep) {
> + dev_err(imx->dev, "failed to find endpoint in device tree\n");
> + return -ENXIO;
> + }
> +
> + /* Only data-lanes and link-frequencies are used from the endpoint */
> + ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
> + fwnode_handle_put(ep);
> + if (ret)
> + return ret;
> +
> + imx->num_lanes = bus_cfg.bus.mipi_csi2.num_data_lanes;
> +
> + if (imx->num_lanes != 2 && imx->num_lanes != 4) {
> + dev_err(imx->dev,
> + "only 2 or 4 CSI-2 data lanes are supported (got %u)\n",
> + imx->num_lanes);
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + ret = v4l2_link_freq_to_bitmap(imx->dev,
> + bus_cfg.link_frequencies,
> + bus_cfg.nr_of_link_frequencies,
> + imx908_link_freqs,
> + ARRAY_SIZE(imx908_link_freqs),
> + &imx->link_freq_bitmap);
> + if (ret) {
> + dev_err(imx->dev, "failed to parse link frequencies from DT\n");
> + goto out_free;
> + }
> +
> + if (bitmap_empty(&imx->link_freq_bitmap, ARRAY_SIZE(imx908_link_freqs))) {
Isn't this handled by -ENOENT retval of v4l2_link_freq_to_bitmap() ?
> + dev_err(imx->dev,
> + "no common link frequencies between driver and DT\n");
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + imx->link_freq_idx = __ffs(imx->link_freq_bitmap);
> + dev_dbg(imx->dev, "using %u lanes at link freq %llu Hz\n",
> + imx->num_lanes, imx908_link_freqs[imx->link_freq_idx]);
> +
> +out_free:
> + v4l2_fwnode_endpoint_free(&bus_cfg);
> + return ret;
> +}
> +
> +static int imx908_init_controls(struct imx908 *imx)
> +{
> + struct v4l2_ctrl_handler *hdl = &imx->ctrls.handler;
> + struct v4l2_fwnode_device_properties props;
> + struct v4l2_ctrl *link_freq_ctl;
> + int ret;
> +
> + ret = v4l2_ctrl_handler_init(hdl, 11);
> + if (ret)
> + return ret;
> +
> + imx->ctrls.pixel_rate = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
> + V4L2_CID_PIXEL_RATE,
> + IMX908_PIXEL_RATE,
> + IMX908_PIXEL_RATE, 1,
> + IMX908_PIXEL_RATE);
> + if (imx->ctrls.pixel_rate)
> + imx->ctrls.pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
Not needed, PIXEL_RATE is marked as RO by the control framework
> +
> + link_freq_ctl = v4l2_ctrl_new_int_menu(hdl, &imx908_ctrl_ops,
> + V4L2_CID_LINK_FREQ,
> + ARRAY_SIZE(imx908_link_freqs) - 1,
> + imx->link_freq_idx,
> + imx908_link_freqs);
> +
> + if (link_freq_ctl)
> + link_freq_ctl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> + imx->hmax = IMX908_HMAX_DEFAULT;
> + imx->vmax = IMX908_VMAX_DEFAULT;
> +
> + u32 min_vblank = IMX908_VMAX_DEFAULT - imx908_active_area.height;
> + u32 max_vblank = imx908_calc_max_vblank(imx908_active_area.height);
> +
> + imx->ctrls.vblank = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
> + V4L2_CID_VBLANK,
> + min_vblank,
> + max_vblank,
> + 1,
> + min_vblank);
> +
> + u8 bpp = imx908_bits_per_pixel(IMX908_DEFAULT_MBUS_CODE);
> + u16 min_hmax = imx908_calc_min_hmax(imx, imx908_active_area.width, bpp);
> + u32 min_hblank = imx908_hmax_to_hblank(min_hmax,
> + imx908_active_area.width);
> + u32 max_hblank = imx908_hmax_to_hblank(IMX908_HMAX_MAX,
> + imx908_active_area.width);
> + u32 hblank = imx908_hmax_to_hblank(IMX908_HMAX_DEFAULT,
> + imx908_active_area.width);
> +
> + /* Default HMAX can be infeasible at low link freqs; clamp into range */
> + hblank = clamp_t(u32, hblank, min_hblank, max_hblank);
> +
> + /* Keep cached HMAX consistent with the clamped default */
> + imx->hmax = imx908_calc_hmax(imx908_active_area.width, hblank);
> +
> + imx->ctrls.hblank = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
> + V4L2_CID_HBLANK,
> + min_hblank,
> + max_hblank,
> + IMX908_PIX_PER_CLK,
> + hblank);
> + u32 max_exp = IMX908_VMAX_DEFAULT - IMX908_MIN_SHR0;
> +
> + imx->ctrls.exposure = v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops,
> + V4L2_CID_EXPOSURE,
> + IMX908_EXPOSURE_MIN,
> + max_exp,
> + IMX908_EXPOSURE_STEP,
> + max_exp / 2);
> +
> + v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_ANALOGUE_GAIN,
> + IMX908_ANA_GAIN_MIN, IMX908_ANA_GAIN_MAX,
> + IMX908_ANA_GAIN_STEP, IMX908_ANA_GAIN_DEFAULT);
> +
> + /* Set test pattern. Menu (13 entries: Disabled + 12 patterns) */
> + imx->ctrls.test_pattern = v4l2_ctrl_new_std_menu_items(hdl,
> + &imx908_ctrl_ops,
> + V4L2_CID_TEST_PATTERN,
> + ARRAY_SIZE(imx908_tpg_menu) - 1,
> + 0,
> + 0,
> + imx908_tpg_menu);
> + if (imx->ctrls.test_pattern)
> + imx->ctrls.test_pattern->flags |= V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
> +
Any particular reason to use this?
I've never needed this for test pattern control before.
> + v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_HFLIP, 0, 1, 1, 0);
> + v4l2_ctrl_new_std(hdl, &imx908_ctrl_ops, V4L2_CID_VFLIP, 0, 1, 1, 0);
> +
> + /* Read rotation and orientation properties from the firmware node */
> + ret = v4l2_fwnode_device_parse(imx->dev, &props);
> + if (ret)
> + goto err_free;
nit: You could move this section before v4l2_ctrl_handler_init() to
simplify error handling and get rid of the goto.
> +
> + v4l2_ctrl_new_fwnode_properties(hdl, &imx908_ctrl_ops, &props);
> + if (hdl->error) {
> + ret = hdl->error;
> + goto err_free;
> + }
> +
> + imx->sd.ctrl_handler = hdl;
> +
> + return 0;
> +
> +err_free:
> + v4l2_ctrl_handler_free(hdl);
> + return ret;
> +}
[...]
> +static int imx908_probe(struct i2c_client *client)
> +{
> + struct imx908 *imx;
> + int ret;
> +
> + imx = devm_kzalloc(&client->dev, sizeof(*imx), GFP_KERNEL);
> + if (!imx)
> + return -ENOMEM;
> + imx->dev = &client->dev;
> +
> + v4l2_i2c_subdev_init(&imx->sd, client, &imx908_subdev_ops);
> + imx->sd.internal_ops = &imx908_internal_ops;
> +
> + imx->cci = devm_cci_regmap_init_i2c(client, 16);
> + if (IS_ERR(imx->cci))
> + return dev_err_probe(&client->dev, PTR_ERR(imx->cci),
> + "CCI regmap init failed\n");
> +
> + imx->xclk = devm_clk_get(imx->dev, NULL);
> + if (IS_ERR(imx->xclk))
> + return dev_err_probe(imx->dev, PTR_ERR(imx->xclk),
> + "failed to get clock\n");
> +
> + ret = imx908_get_inck_sel(imx, clk_get_rate(imx->xclk));
> + if (ret)
> + return ret;
> +
> + imx->reset_gpio = devm_gpiod_get_optional(imx->dev, "reset",
> + GPIOD_OUT_HIGH);
> +
> + if (IS_ERR(imx->reset_gpio))
> + return dev_err_probe(imx->dev, PTR_ERR(imx->reset_gpio),
> + "failed to get reset gpio\n");
> +
> + ret = imx908_get_regulators(imx);
> + if (ret)
> + return dev_err_probe(&client->dev, ret,
> + "failed to get regulators\n");
> +
> + ret = imx908_parse_fwnode(imx);
> + if (ret)
> + return dev_err_probe(&client->dev, ret,
> + "device tree parse failed\n");
> +
> + ret = imx908_power_on(imx);
> + if (ret)
> + return dev_err_probe(&client->dev, ret, "power-on failed\n");
> +
> + ret = imx908_identify_model(imx);
> + if (ret) {
> + dev_err(imx->dev, "failed to identify model: %d\n", ret);
> + goto err_power_off;
> + }
> +
> + pm_runtime_set_active(imx->dev);
> + pm_runtime_enable(imx->dev);
> +
> + ret = imx908_init_controls(imx);
> + if (ret)
> + goto err_pm_disable;
> +
> + imx->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
Drop.
See 17971a430ff9 ("media: i2c: Drop HAS_EVENTS and event handlers")
> + imx->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> + imx->pad.flags = MEDIA_PAD_FL_SOURCE;
> + ret = media_entity_pads_init(&imx->sd.entity, 1, &imx->pad);
> + if (ret)
> + goto err_hdl;
> +
> + /* Share the ctrl handler lock so s_ctrl can access the locked state */
> + imx->sd.state_lock = imx->ctrls.handler.lock;
> +
> + ret = v4l2_subdev_init_finalize(&imx->sd);
> + if (ret)
> + goto err_entity;
> +
> + pm_runtime_set_autosuspend_delay(imx->dev, 1000);
> + pm_runtime_use_autosuspend(imx->dev);
> + pm_runtime_mark_last_busy(imx->dev);
> +
Missing pm_runtime_idle(), and this whole block should probably go just
before the `return 0`.
[...]
Thanks,
Jai
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2026-08-07 6:53 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-06 7:09 [PATCH v2 0/2] Add bindings and driver for Sony IMX908 Lachlan Michael
2026-08-06 7:09 ` [PATCH v2 1/2] media: dt-bindings: imx908: Add Sony IMX908 sensor Lachlan Michael
2026-08-06 7:20 ` sashiko-bot
2026-08-06 7:09 ` [PATCH v2 2/2] media: i2c: Add Sony IMX908 image sensor driver Lachlan Michael
2026-08-06 7:26 ` sashiko-bot
2026-08-06 16:50 ` Dave Stevenson
2026-08-07 6:53 ` Jai Luthra
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