[PATCH v2 0/2] media: i2c: add support for ITE IT6625/IT6626 HDMI to MIPI CSI-2 bridge

[PATCH v2 0/2] media: i2c: add support for ITE IT6625/IT6626 HDMI to MIPI CSI-2 bridge

[Hermes Wu via B4 Relay]

This series adds support for the ITE IT6625/IT6626 HDMI to MIPI CSI-2
bridge chips. IT6625 accepts an HDMI 2.0 input and IT6626 an HDMI 2.1
input, converting it to a D-PHY (or C/D-PHY on IT6626) MIPI CSI-2
output. The bridge is configured over I2C, exposes an HDMI CEC
adapter, and supports EDID read/write, DV timings detection and
configuration, and HPD control via the standard V4L2 subdevice pad
and video ops.

Patch 1 documents the devicetree binding for the bridge, including
its three graph ports (two selectable CSI-2 outputs and one HDMI
input).

Patch 2 adds the V4L2 subdevice driver itself.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
Changes in v2:
- Patch 2 (driver): fix several correctness issues found by automated
  review of v1 -- premature V4L2 async subdev registration/teardown
  ordering, a missing-lock race on banked register reads, a
  status-poll interval bug, a dropped CEC interrupt, an unacked CEC
  transmit, set_fmt mutating active state on TRY, EDID blocks=0
  handling, and a couple of uninitialized-stack hardening fixes. See
  the patch's own changelog for the full list.
- Patch 1 (dt-bindings): restrict port@0/port@1 bus-type to D-PHY (4)
  only for "ite,it6625", since that chip doesn't support C-PHY (also
  found by the automated review of v1).
- Link to v1: https://lore.kernel.org/r/20260720-upstream-it6625-it6626-v1-0-475912f74459@ite.com.tw

---
Hermes Wu (2):
      dt-bindings: media: add ITE IT6625/IT6626 HDMI bridge binding
      media: i2c: add driver for ITE IT6625/IT6626

 .../devicetree/bindings/media/i2c/ite,it6625.yaml  |  159 ++
 MAINTAINERS                                        |    7 +
 drivers/media/i2c/Kconfig                          |   18 +
 drivers/media/i2c/Makefile                         |    1 +
 drivers/media/i2c/it6625.c                         | 2104 ++++++++++++++++++++
 5 files changed, 2289 insertions(+)
---
base-commit: 8dac27bfa2f994ecb11f01a63641527d17d48fc1
change-id: 20260716-upstream-it6625-it6626-6874ab8a5305

Best regards,
-- 
Hermes Wu <Hermes.wu@ite.com.tw>

[PATCH v2 1/2] dt-bindings: media: add ITE IT6625/IT6626 HDMI bridge binding

[Hermes Wu via B4 Relay]

From: Hermes Wu <Hermes.wu@ite.com.tw>

Document the devicetree binding for the ITE IT6625/IT6626 HDMI to
MIPI CSI-2 bridge. The device exposes three graph ports: port@0
(MIPI0) and port@1 (MIPI1) are the two selectable CSI-2 D-PHY/C-PHY
outputs, and port@2 is the HDMI connector input. Only port@0 is
required, since a board only needs to wire up as many of the bridge's
outputs as it actually uses.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
Changes in v2:
- Restrict port@0/port@1 endpoint bus-type to D-PHY (4) only when
  compatible is "ite,it6625", via an allOf/if/then constraint. IT6625
  only supports MIPI CSI-2 D-PHY output; the schema previously allowed
  both C-PHY (1) and D-PHY (4) unconditionally, so a devicetree
  claiming "ite,it6625" with bus-type = C-PHY passed schema validation
  despite being invalid on that hardware. IT6626, which supports both
  PHY types, is unaffected. Found by the sashiko.dev automated review
  of v1.
---
 .../devicetree/bindings/media/i2c/ite,it6625.yaml  | 159 +++++++++++++++++++++
 1 file changed, 159 insertions(+)

diff --git a/Documentation/devicetree/bindings/media/i2c/ite,it6625.yaml b/Documentation/devicetree/bindings/media/i2c/ite,it6625.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..9bc5584b48880ce1d0796ca3ab35d4d334732f72
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/ite,it6625.yaml
@@ -0,0 +1,159 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/ite,it6625.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ITE IT6625/IT6626 HDMI to dual MIPI CSI-2 bridge
+
+maintainers:
+  - Hermes Wu <Hermes.wu@ite.com.tw>
+
+description: |-
+  The ITE IT6625 and IT6626 are HDMI to MIPI CSI-2 bridge devices.
+  IT6625 supports an HDMI 2.0 input and converts it to one or two D-PHY CSI
+  outputs, while IT6626 supports an HDMI 2.1 input and converts it to one or
+  two C/D-PHY CSI outputs. The bridges are programmable through I2C and
+  expose one HDMI input port and two selectable CSI-2 output ports. The
+  bridge can operate in split mode or clone mode.
+
+properties:
+  compatible:
+    enum:
+      - ite,it6625
+      - ite,it6626
+
+  reg:
+    maxItems: 1
+
+  reset-gpios:
+    description:
+      GPIO connected to the active-low reset line.
+    maxItems: 1
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+    properties:
+      port@0:
+        $ref: /schemas/graph.yaml#/$defs/port-base
+        unevaluatedProperties: false
+        description: CSI-2 output port MIPI0
+
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              data-lanes:
+                minItems: 1
+                maxItems: 4
+
+              bus-type:
+                enum:
+                  - 1 # MEDIA_BUS_TYPE_CSI2_CPHY
+                  - 4 # MEDIA_BUS_TYPE_CSI2_DPHY
+
+              clock-noncontinuous: true
+              link-frequencies: true
+
+            required:
+              - data-lanes
+
+      port@1:
+        $ref: /schemas/graph.yaml#/$defs/port-base
+        unevaluatedProperties: false
+        description: CSI-2 output port MIPI1
+
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              data-lanes:
+                minItems: 1
+                maxItems: 4
+
+              bus-type:
+                enum:
+                  - 1 # MEDIA_BUS_TYPE_CSI2_CPHY
+                  - 4 # MEDIA_BUS_TYPE_CSI2_DPHY
+
+              clock-noncontinuous: true
+              link-frequencies: true
+
+            required:
+              - data-lanes
+
+      port@2:
+        $ref: /schemas/graph.yaml#/$defs/port-base
+        unevaluatedProperties: false
+        description: HDMI connector input port
+
+        properties:
+          endpoint:
+            $ref: /schemas/graph.yaml#/$defs/endpoint-base
+            unevaluatedProperties: false
+
+    required:
+      - port@0
+required:
+  - compatible
+  - reg
+  - ports
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: ite,it6625
+    then:
+      properties:
+        ports:
+          properties:
+            port@0:
+              properties:
+                endpoint:
+                  properties:
+                    bus-type:
+                      const: 4
+            port@1:
+              properties:
+                endpoint:
+                  properties:
+                    bus-type:
+                      const: 4
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      hdmi-bridge@4c {
+        compatible = "ite,it6625";
+        reg = <0x4c>;
+
+        reset-gpios = <&gpio 2 GPIO_ACTIVE_LOW>;
+
+        ports {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          port@0 {
+            reg = <0>;
+            csi_out0: endpoint {
+              remote-endpoint = <&csi2_rx0>;
+              bus-type = <4>; /* MEDIA_BUS_TYPE_CSI2_DPHY */
+              data-lanes = <1 2 3 4>;
+            };
+          };
+        };
+      };
+    };

-- 
2.34.1

[PATCH v2 2/2] media: i2c: add driver for ITE IT6625/IT6626

[Hermes Wu via B4 Relay]

From: Hermes Wu <Hermes.wu@ite.com.tw>

Add a V4L2 subdevice driver for the ITE IT6625/IT6626 HDMI-to-MIPI
CSI-2 bridge chips. IT6625 accepts an HDMI 2.0 input and IT6626 an
HDMI 2.1 input, converting it to a D-PHY (or C/D-PHY on IT6626)
MIPI CSI-2 output. The bridge is configured over I2C, exposes an
HDMI CEC adapter, and supports EDID read/write, DV timings
detection/configuration, and HPD control via the standard V4L2
subdevice pad and video ops.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
Changes in v2:
- Fix premature v4l2_async_register_subdev(): move it to the end of
  probe() (after ctrl handler, CEC and initial hardware setup), and
  mirror the unregister order at the top of remove(), closing a
  use-after-free window where a concurrent ioctl could reschedule
  hpd_delayed_work during teardown.
- Take it6625_lock around the banked register reads in
  it6625_get_detected_timings() and the CEC RX path in
  it6625_cec_handler(), which could otherwise race with an in-progress
  EDID read/write and observe the wrong bank.
- Fix it6625_wait_for_status()'s poll interval exceeding the timeout
  budget, split the CEC RX/TX interrupt handling out of an else-if so
  simultaneous events aren't dropped, and wait for hardware to latch
  the CEC transmit trigger bit before releasing the lock.
- Stop it6625_set_fmt() from mutating active state on
  V4L2_SUBDEV_FORMAT_TRY, and handle edid->blocks == 0 in g_edid/s_edid
  per the V4L2 spec (capacity query / EDID clear).
- Zero-initialize the CEC rxmsg and debugfs mipi_reg write buffer to
  avoid leaking uninitialized stack bytes, and use designated
  initializers in the i2c_device_id table.

All found by the sashiko.dev automated review of v1.
---
 MAINTAINERS                |    7 +
 drivers/media/i2c/Kconfig  |   18 +
 drivers/media/i2c/Makefile |    1 +
 drivers/media/i2c/it6625.c | 2104 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 2130 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 15011f5752a994cf1b354f490d6c4e411588df88..2d5b0ee107f9e3255a5365ec0a25167a716b1e6e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13847,6 +13847,13 @@ T:	git https://gitlab.freedesktop.org/drm/misc/kernel.git
 F:	Documentation/devicetree/bindings/display/bridge/ite,it66121.yaml
 F:	drivers/gpu/drm/bridge/ite-it66121.c
 
+ITE IT6625 HDMI to MIPI MEDIA DRIVER
+M:	Hermes Wu <Hermes.Wu@ite.com.tw>
+S:	Maintained
+T:	git git://linuxtv.org/media.git
+F:	Documentation/devicetree/bindings/media/i2c/ite,it6625.yaml
+F:	drivers/media/i2c/it6625.c
+
 IVTV VIDEO4LINUX DRIVER
 M:	Andy Walls <awalls@md.metrocast.net>
 L:	linux-media@vger.kernel.org
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 5d173e0ecf424f2f204f8d426be818e44357f8e4..fb4b24684f7710f90eb399976d11f57701488d26 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1278,6 +1278,24 @@ config VIDEO_ISL7998X
 	  Support for Intersil ISL7998x analog to MIPI-CSI2 or
 	  BT.656 decoder.
 
+config VIDEO_IT6625
+	tristate "IT6625 HDMI to MIPI CSI bridge"
+	depends on VIDEO_DEV && I2C
+	depends on OF
+	select CEC_CORE
+	select MEDIA_CONTROLLER
+	select REGMAP_I2C
+	select V4L2_FWNODE
+	select VIDEO_V4L2_SUBDEV_API
+	help
+	  V4L2 subdevice driver for the ITE IT6625/IT6626 HDMI to MIPI
+	  CSI-2 bridge chips. IT6625 accepts an HDMI 2.0 input and
+	  IT6626 an HDMI 2.1 input, converting it to a MIPI CSI-2
+	  output. The driver also exposes an HDMI CEC adapter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called it6625.
+
 config VIDEO_LT6911UXE
 	tristate "Lontium LT6911UXE decoder"
 	depends on ACPI && VIDEO_DEV && I2C
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index e45359efe0e41e13e3c0869e5ead7d6cf4aca3a7..9bbceaa3d07573958edb8a36bc7f0942f1410a39 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -63,6 +63,7 @@ obj-$(CONFIG_VIDEO_IMX412) += imx412.o
 obj-$(CONFIG_VIDEO_IMX415) += imx415.o
 obj-$(CONFIG_VIDEO_IR_I2C) += ir-kbd-i2c.o
 obj-$(CONFIG_VIDEO_ISL7998X) += isl7998x.o
+obj-$(CONFIG_VIDEO_IT6625) += it6625.o
 obj-$(CONFIG_VIDEO_KS0127) += ks0127.o
 obj-$(CONFIG_VIDEO_LM3560) += lm3560.o
 obj-$(CONFIG_VIDEO_LM3646) += lm3646.o
diff --git a/drivers/media/i2c/it6625.c b/drivers/media/i2c/it6625.c
new file mode 100644
index 0000000000000000000000000000000000000000..689739eb3f190a6ac4f0efb801f7dced6c00b46e
--- /dev/null
+++ b/drivers/media/i2c/it6625.c
@@ -0,0 +1,2104 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * it6625 - ite HDMI to MIPI bridge
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/hdmi.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_graph.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/v4l2-dv-timings.h>
+#include <linux/videodev2.h>
+#include <linux/workqueue.h>
+
+#include <media/cec.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-dv-timings.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fwnode.h>
+
+static int debug = 3;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "debug level (0-3)");
+
+#define REG_CHIP_ID_0 0x00
+#define REG_CHIP_ID_1 0x01
+#define REG_FW_VER_MAJOR 0x03
+#define REG_FW_VER_MINOR 0x04
+#define REG_PROTOCOL_VERSION 0x05
+#define B_PVER_MINOR  BIT(0)
+#define B_PVER_MAJOR  BIT(4)
+
+#define REG_CMD_SET 0x10
+#define CMD_SET_CEC_LA 0xC0
+#define CMD_SET_CEC_ENABLE 0xC1
+
+#define REG_EDID_START 0x20
+#define REG_CEC_RX_DATA 0x20
+#define REG_CEC_TX_DATA 0x30
+
+#define REG_H_ACTIVE_1 0x50
+#define REG_H_ACTIVE_0 0x51
+#define REG_V_ACTIVE_1 0x52
+#define REG_V_ACTIVE_0 0x53
+#define REG_H_TOTAL_1 0x54
+#define REG_H_TOTAL_0 0x55
+#define REG_V_TOTAL_1 0x56
+#define REG_V_TOTAL_0 0x57
+#define REG_VID_PCLK 0x58
+#define REG_H_FP_1 0x5C
+#define REG_H_FP_0 0x5D
+#define REG_H_SW_1 0x5E
+#define REG_H_SW_0 0x5F
+#define REG_H_BP_1 0x60
+#define REG_H_BP_0 0x61
+#define REG_V_FP_1 0x62
+#define REG_V_FP_0 0x63
+#define REG_V_SW_1 0x64
+#define REG_V_SW_0 0x65
+#define REG_V_BP_1 0x66
+#define REG_V_BP_0 0x67
+#define REG_VID_INFO 0x68
+#define B_INTERLACE  BIT(0)
+#define B_HSWPOL  BIT(1)
+#define B_VSWPOL  BIT(2)
+#define B_PIXEL_REP  BIT(4)
+
+#define REG_VIC 0x69
+#define REG_HDMI_VIDEO_INFO 0x6A
+#define B_COLOR_MODE  BIT(0)
+#define B_COLOR_DEPTH  BIT(4)
+#define REG_HDMI_AUDIO_INFO1 0x6B
+#define B_AUD_FS  BIT(0)
+
+#define REG_HDMI_AUDIO_INFO2 0x6C
+#define B_AUD_CH  BIT(0)
+#define B_AUD_WL  BIT(4)
+
+#define REG_HDMI_AUDIO_INFO3 0x6D
+#define B_AUD_TYPE  BIT(0)
+#define B_AUD_MS  BIT(2)
+#define B_AUD_3D  BIT(3)
+
+#define REG_AUDIO_FMT 0x6E
+#define B_I2S_WL  BIT(0)
+#define B_I2S_ALN BIT(2)
+#define B_I2S_DLY BIT(3)
+#define B_I2S_LR  BIT(4)
+#define B_I2S_SFT BIT(5)
+#define B_AUD_OUT_IF  BIT(6)
+
+#define REG_IF_LATCH_HB 0x6F
+#define REG_IF_DATA 0x70
+#define REG_EMP_DATA 0xA0
+#define REG_AVI_DATA 0xAE
+
+#define REG_TX_STATUS 0xE0
+
+#define REG_RX_STATUS 0xE2
+#define B_RX_5V BIT(0)
+#define B_RX_HPD BIT(1)
+#define B_RX_STABLE BIT(2)
+#define B_RX_HDMI BIT(3)
+#define B_RX_AVMUTE BIT(4)
+#define B_RX_AUD_ON BIT(5)
+
+#define REG_RX_HDCP_STS 0xE3
+#define B_HDCP1_AUTH_START BIT(0)
+#define B_HDCP2_AUTH_START BIT(1)
+#define B_HDCP_AUTH_DONE BIT(2)
+#define B_HDCP_ENC BIT(3)
+
+#define REG_CEC_STATUS 0xE4
+#define B_CEC_TX_DONE BIT(0)
+#define B_CEC_TX_NACK BIT(1)
+
+#define REG_CEC_RX_DATA_LEN 0xE5
+#define REG_CEC_TX_DATA_LEN 0xE6
+
+#define REG_SYS_MIPI_INT 0xEB
+#define B_MIPI_OUTPUT_ENABLE BIT(0)
+#define B_MIPI_VIDEO_UNSTABLE BIT(1)
+
+#define REG_RX_INT_STATUS1 0xEC
+#define B_HDMI_5V_CHG   BIT(0)
+#define B_HDMI_VID_CHG  BIT(1)
+#define B_HDMI_AUD_CHG  BIT(2)
+#define B_HDMI_CP_CHG   BIT(3)
+#define B_HDMI_IF_LATCH BIT(4)
+#define B_HDMI_NO_IF_LATCH  BIT(5)
+#define B_HDMI_EMP      BIT(6)
+#define B_HDMI_NO_EMP   BIT(7)
+
+#define REG_RX_INT_STATUS2 0xED
+#define B_HDMI_AVI      BIT(0)
+#define B_HDMI_NO_AVI   BIT(1)
+#define B_HDMI_VSIF     BIT(2)
+#define B_HDMI_NO_VSIF  BIT(3)
+#define B_HDMI_AVMUTE_CHG  BIT(4)
+
+#define REG_CHIP_CONTROL 0xF0
+#define B_HDMI_RESET  BIT(5)
+#define B_FW_START  BIT(6)
+
+#define REG_MIPI_CFG 0xF1
+#define M_MIPI_LANE  0x03
+#define B_MIPI_SPLIT  BIT(2)
+#define B_MIPI_SPLIT_CFG  BIT(3)
+#define B_MIPI_DPHY  BIT(4)
+#define B_MIPI_USE_DSI  BIT(5)
+#define B_MIPI_CONTINU_CLK  BIT(6)
+
+#define REG_MIPI_DATA_TYPE 0xF2
+#define CSI_RGB444          0x20
+#define CSI_RGB555          0x21
+#define CSI_RGB565          0x22
+#define CSI_RGB666          0x23
+#define CSI_RGB888          0x24
+#define CSI_YUV420_8b_L     0x1A
+#define CSI_YUV420_8b       0x1C
+#define CSI_YUV420_10b      0x1D
+#define CSI_YUV422_8b       0x1E
+#define CSI_YUV422_10b      0x1F
+#define CSI_RGB_10b         0x30
+#define CSI_RGB_12b         0x31
+#define CSI_YUV422_12b      0x32
+#define CSI_YUV420_10b_L    0x33
+#define CSI_YUV420_12b      0x34
+#define CSI_YUV444_8b       0x35
+#define CSI_YUV444_10b      0x36
+#define CSI_YUV444_12b      0x37
+
+#define REG_MIPI_CONTROL 0xF3
+#define B_MIPI_OUTPUT    BIT(0)
+
+#define REG_RX_CFG 0xF4
+#define B_MANUAL_HPD    BIT(0)
+#define B_HPD_HIGH    BIT(1)
+#define B_HPD_TOGGLE    BIT(3)
+
+#define REG_CSC_CFG 0xF5
+#define B_DYNAMIC_RANGE BIT(0)
+
+#define REG_MISC_CFG 0xF6
+#define B_BAUD_RATE BIT(0)
+#define B_DEBUG_MSG BIT(1)
+
+#define REG_HPD_DELAY 0xF7
+#define B_DELAY_COUNT BIT(0)
+#define B_DELAY_UNIT BIT(7)
+
+#define REG_INFO_BANK_SEL 0xFD
+#define CTL_BANK_EDID_READ 1
+#define CTL_BANK_EDID_WRITE 5
+
+#define REG_HOST_CTRL_INT 0xFE
+#define B_CMD_SET BIT(4)
+#define B_CEC_SEND_DATA BIT(5)
+#define B_CONFIG_UPDATE BIT(6)
+#define B_IF_BANK BIT(7)
+
+#define REG_MCU_INTERRUPT 0xFF
+#define B_SYS_INT_ACTIVE BIT(0)
+#define B_CEC_RX_RECEIVED BIT(1)
+#define B_CEC_TX_UPDATE BIT(2)
+
+#define EDID_NUM_BLOCKS_MAX 4
+#define EDID_BLOCK_SIZE 128
+
+#define I2C_MAX_XFER_SIZE  8
+#define POLL_INTERVAL_CEC_MS	10
+#define POLL_INTERVAL_MS	40
+
+#define AUD32K   0x03
+#define AUD44K   0x00
+#define AUD48K   0x02
+#define AUD64K   0x0B
+#define AUD88K   0x08
+#define AUD96K   0x0A
+#define AUD128K  0x2B
+#define AUD176K  0x0C
+#define AUD192K  0x0E
+#define AUD256K  0x1B
+#define AUD352K  0x0D
+#define AUD384K  0x05
+#define AUD512K  0x3B
+#define AUD705K  0x2D
+#define AUD768K  0x09
+#define AUD1024K 0x35
+#define AUD1411K 0x1D
+#define AUD1536K 0x15
+
+enum it6625_chip_type {
+	IT6625_CHIP = 0,
+	IT6626_CHIP = 1,
+};
+
+struct it6625 {
+	struct device *dev;
+	struct i2c_client *i2c_client;
+	struct regmap *it6625_regmap;
+	enum it6625_chip_type chip_type;
+
+	/* protects concurrent access to the chip's registers and state */
+	struct mutex it6625_lock;
+
+	struct v4l2_subdev sd;
+	struct v4l2_mbus_config_mipi_csi2 bus;
+	struct video_device *vdev;
+	struct media_pad pad;
+	struct v4l2_ctrl_handler hdl;
+
+	/* controls */
+	struct v4l2_ctrl *ctrl_5v_detect;
+	struct v4l2_ctrl *ctrl_audio_sampling_rate;
+	struct v4l2_ctrl *ctrl_audio_present;
+	struct v4l2_ctrl *ctrl_link_freq;
+	struct v4l2_ctrl *ctrl_get_hdmi_info;
+	struct v4l2_ctrl *ctrl_mipi_config;
+
+	struct delayed_work hpd_delayed_work;
+
+	struct timer_list timer;
+	struct work_struct polling_work;
+
+	struct v4l2_dv_timings timings;
+
+	u8 csi_lanes;
+	u8 port_num;
+	enum v4l2_mbus_type bus_type;
+	u8 csi_format;
+	u32 mbus_fmt_code;
+
+	struct gpio_desc *reset_gpio;
+
+	struct cec_adapter *cec_adap;
+
+	struct dentry *debugfs_dir;
+};
+
+static const s64 it6625_link_freq[] = { 445500000 };
+
+static const struct v4l2_dv_timings_cap it6625_timings_cap = {
+	.type = V4L2_DV_BT_656_1120,
+	/* keep this initialization for compatibility with GCC < 4.4.6 */
+	.reserved = { 0 },
+
+	V4L2_INIT_BT_TIMINGS(640, 3840, 480, 2160, 27000000, 300000000,
+			     V4L2_DV_BT_STD_CEA861 | V4L2_DV_BT_STD_DMT |
+			     V4L2_DV_BT_STD_GTF | V4L2_DV_BT_STD_CVT,
+			     V4L2_DV_BT_CAP_PROGRESSIVE | V4L2_DV_BT_CAP_INTERLACED |
+			     V4L2_DV_BT_CAP_REDUCED_BLANKING | V4L2_DV_BT_CAP_CUSTOM)
+};
+
+static const struct it6625_format_info {
+	u8 csi_format;
+	u32 mbus_fmt_code;
+} it6625_formats[] = {
+	{ CSI_YUV422_8b, MEDIA_BUS_FMT_UYVY8_1X16 },
+	{ CSI_RGB888, MEDIA_BUS_FMT_RGB888_1X24 },
+	{ CSI_YUV444_8b, MEDIA_BUS_FMT_YUV8_1X24 },
+};
+
+static inline int it6625_csi_format_idx(u8 csi_format)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(it6625_formats); i++) {
+		if (it6625_formats[i].csi_format == csi_format)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static inline int it6625_csi_mbus_code_idx(u32 mbus_fmt_code)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(it6625_formats); i++) {
+		if (it6625_formats[i].mbus_fmt_code == mbus_fmt_code)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static inline struct it6625 *sd_to_6625(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct it6625, sd);
+}
+
+static inline struct it6625 *hdl_to_6625(struct v4l2_ctrl_handler *hdl)
+{
+	return container_of(hdl, struct it6625, hdl);
+}
+
+static const struct regmap_config it6625_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+	.cache_type = REGCACHE_NONE,
+	.max_raw_read = I2C_MAX_XFER_SIZE,
+	.max_raw_write = I2C_MAX_XFER_SIZE,
+};
+
+static int it6625_regmap_i2c_init(struct i2c_client *client,
+				  struct it6625 *it6625)
+{
+	it6625->i2c_client = client;
+	it6625->dev = &client->dev;
+
+	it6625->it6625_regmap = devm_regmap_init_i2c(it6625->i2c_client,
+						     &it6625_regmap_config);
+	if (IS_ERR(it6625->it6625_regmap))
+		return PTR_ERR(it6625->it6625_regmap);
+
+	return 0;
+}
+
+static int it6625_read_byte(struct it6625 *it6625, u8 reg)
+{
+	unsigned int val;
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_read(it6625->it6625_regmap, reg, &val);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] read failed err: %d", reg, err);
+		return err;
+	}
+
+	return val;
+}
+
+static int it6625_write_byte(struct it6625 *it6625, u8 reg, u8 val)
+{
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_write(it6625->it6625_regmap, reg, val);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] write failed err: %d", reg, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_set_bits(struct it6625 *it6625, u8 reg, u8 mask, u8 val)
+{
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_update_bits(it6625->it6625_regmap, reg, mask, val);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] set bits failed err: %d", reg, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_read_bytes(struct it6625 *it6625, u8 reg, u8 *buf, int len)
+{
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_bulk_read(it6625->it6625_regmap, reg, buf, len);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] read failed err: %d", reg, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_write_bytes(struct it6625 *it6625, u8 reg, u8 *buf, int len)
+{
+	int err;
+	struct device *dev = it6625->dev;
+
+	err = regmap_bulk_write(it6625->it6625_regmap, reg, buf, len);
+	if (err < 0) {
+		dev_err(dev, "reg[0x%x] write failed err: %d", reg, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_wait_for_status(struct it6625 *it6625, u8 reg, u8 val,
+				  int timeout_ms)
+{
+	struct device *dev = it6625->dev;
+	int status;
+	int rval;
+	int sleep_ms = 10;
+	int timeout_round_ms = DIV_ROUND_UP(timeout_ms, sleep_ms) * sleep_ms;
+
+	status = read_poll_timeout(it6625_read_byte, rval, rval == val,
+				   sleep_ms * 1000,
+				   timeout_round_ms * 1000,
+				   false, it6625, reg);
+
+	dev_info(dev, "%s status = %d %d", __func__, status, (int)rval);
+	if (status < 0) {
+		dev_err(dev, "%s err status = %d", __func__, status);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void it6625_write_command(struct it6625 *it6625, u8 *cmds, int cmd_len)
+{
+	it6625_write_bytes(it6625, REG_CMD_SET, cmds, cmd_len);
+	it6625_write_byte(it6625, REG_HOST_CTRL_INT, B_CMD_SET);
+	it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+}
+
+static int it6625_update_config(struct it6625 *it6625)
+{
+	int err;
+
+	err = it6625_set_bits(it6625, REG_HOST_CTRL_INT,
+			      B_CONFIG_UPDATE, B_CONFIG_UPDATE);
+	if (err < 0)
+		return err;
+
+	return it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+}
+
+static int it6625_set_bank(struct it6625 *it6625, u8 bank)
+{
+	int err;
+
+	err = it6625_write_byte(it6625, REG_INFO_BANK_SEL, bank);
+	if (err < 0)
+		return err;
+
+	err = it6625_write_byte(it6625, REG_HOST_CTRL_INT, B_IF_BANK);
+	if (err < 0)
+		return err;
+
+	return it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+}
+
+static inline bool is_hdmi(struct it6625 *it6625)
+{
+	int val;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	return (val < 0) ? false : (val & B_RX_HDMI);
+}
+
+static inline bool hdmi_5v_power_present(struct it6625 *it6625)
+{
+	int val;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	return (val < 0) ? false : (val & B_RX_5V);
+}
+
+static inline bool no_signal(struct it6625 *it6625)
+{
+	int val;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	return (val < 0) ? true : !(val & B_RX_STABLE);
+}
+
+static inline bool audio_present(struct it6625 *it6625)
+{
+	int val;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	return (val < 0) ? false : (val & B_RX_AUD_ON);
+}
+
+static int get_audio_sampling_rate(struct it6625 *it6625)
+{
+	u8 fs_id;
+	int i, freq = 0;
+	const struct fs_id_map {
+		u8 fs_id;
+		u16 freq;
+	} s_fsid_map[] = {
+		{ AUD32K, 32 },
+		{ AUD44K, 44 },
+		{ AUD48K, 48 },
+		{ AUD64K, 64 },
+		{ AUD88K, 88 },
+		{ AUD96K, 96 },
+
+		{ AUD128K, 128 },
+		{ AUD176K, 176 },
+		{ AUD192K, 192 },
+		{ AUD256K, 256 },
+		{ AUD352K, 352 },
+		{ AUD384K, 384 },
+
+		{ AUD512K, 512 },
+		{ AUD705K, 705 },
+		{ AUD768K, 768 },
+		{ AUD1024K, 1024 },
+		{ AUD1411K, 1411 },
+		{ AUD1536K, 1536 },
+	};
+
+	if (no_signal(it6625) || !audio_present(it6625))
+		return 0;
+
+	fs_id = it6625_read_byte(it6625, REG_HDMI_AUDIO_INFO1);
+
+	for (i = 0; i < ARRAY_SIZE(s_fsid_map); i++) {
+		if (s_fsid_map[i].fs_id == fs_id) {
+			freq = s_fsid_map[i].freq * 1000;
+			break;
+		}
+	}
+
+	return freq;
+}
+
+static u64 it6625_get_pclk(struct it6625 *it6625)
+{
+	u32 pclk;
+	u8 ck[4];
+	int ret;
+
+	ret = it6625_read_bytes(it6625, REG_VID_PCLK, ck, 4);
+	if (ret < 0) {
+		dev_err(it6625->dev, "failed to read pixel clock");
+		return 0;
+	}
+
+	pclk = ck[0];
+	pclk <<= 8;
+	pclk |= ck[1];
+	pclk <<= 8;
+	pclk |= ck[2];
+	pclk <<= 8;
+	pclk |= ck[3];
+
+	v4l2_dbg(1, debug, &it6625->sd, "%s: pclk=%u (%08x)",
+		 __func__, pclk, pclk);
+
+	return (u64)pclk * 1000;
+}
+
+static int it6625_read_edid(struct it6625 *it6625, u8 *edid, int start_block,
+			    int num_blocks)
+{
+	int i, bank_ctrl, err = 0;
+	struct device *dev = it6625->dev;
+
+	if (!edid) {
+		dev_err(dev, "edid buffer is NULL");
+		return -EINVAL;
+	}
+
+	if (start_block < 0 || num_blocks <= 0 ||
+	    start_block + num_blocks > EDID_NUM_BLOCKS_MAX) {
+		dev_err(dev,
+			"invalid block range: start_block=%d, num_blocks=%d",
+			start_block, num_blocks);
+		return -EINVAL;
+	}
+
+	guard(mutex)(&it6625->it6625_lock);
+	for (i = 0; i < num_blocks; i++) {
+		bank_ctrl = CTL_BANK_EDID_READ + start_block + i;
+		err = it6625_set_bank(it6625, bank_ctrl);
+		if (err < 0)
+			break;
+
+		err = it6625_read_bytes(it6625, REG_EDID_START,
+					edid + (i * 128), 128);
+		if (err < 0)
+			break;
+	}
+
+	it6625_set_bank(it6625, 0);
+
+	return err < 0 ? err : num_blocks;
+}
+
+static int it6625_write_edid(struct it6625 *it6625, u8 *edid, int start_block,
+			     int num_blocks)
+{
+	int i, bank_ctrl, err = 0;
+	struct device *dev = it6625->dev;
+
+	if (start_block < 0 || num_blocks <= 0 ||
+	    start_block + num_blocks > EDID_NUM_BLOCKS_MAX) {
+		dev_err(dev,
+			"invalid block range: start_block=%d, num_blocks=%d",
+			start_block, num_blocks);
+		return -EINVAL;
+	}
+
+	guard(mutex)(&it6625->it6625_lock);
+	for (i = 0; i < num_blocks; i++) {
+		bank_ctrl = CTL_BANK_EDID_WRITE + start_block + i;
+		err = it6625_set_bank(it6625, bank_ctrl);
+		if (err < 0)
+			break;
+
+		err = it6625_write_bytes(it6625, REG_EDID_START,
+					 edid + (i * 128), 128);
+		if (err < 0)
+			break;
+
+		err = it6625_update_config(it6625);
+		if (err < 0)
+			break;
+	}
+
+	it6625_set_bank(it6625, 0);
+
+	return err < 0 ? err : num_blocks;
+}
+
+static void it6625_enable_auto_hpd(struct it6625 *it6625)
+{
+	dev_dbg(it6625->dev, "%s: auto HPD", __func__);
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_set_bits(it6625, REG_RX_CFG, 0x03, 0x00);
+	it6625_update_config(it6625);
+}
+
+static void it6625_disable_hpd(struct it6625 *it6625)
+{
+	cancel_delayed_work_sync(&it6625->hpd_delayed_work);
+
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_set_bits(it6625, REG_RX_CFG, 0x03, 0x01);
+	it6625_update_config(it6625);
+}
+
+static void it6625_enable_hpd(struct it6625 *it6625)
+{
+	schedule_delayed_work(&it6625->hpd_delayed_work,
+			      msecs_to_jiffies(100));
+}
+
+static void it6625_hpd_delayed_work(struct work_struct *work)
+{
+	struct it6625 *it6625 = container_of(work,
+			struct it6625, hpd_delayed_work.work);
+	int val = 0;
+
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_set_bits(it6625, REG_RX_CFG, 0x03, val);
+	it6625_update_config(it6625);
+}
+
+static int it6625_get_detected_timings(struct it6625 *it6625,
+				       struct v4l2_dv_timings *timings)
+{
+	struct v4l2_bt_timings *bt = &timings->bt;
+	int val;
+	unsigned int width, height, frame_width, frame_height;
+	u8 buffer[8];
+
+	if (no_signal(it6625)) {
+		dev_err(it6625->dev, "no signal detected");
+		return -ENOLINK;
+	}
+
+	guard(mutex)(&it6625->it6625_lock);
+
+	memset(timings, 0, sizeof(struct v4l2_dv_timings));
+	timings->type = V4L2_DV_BT_656_1120;
+	val = it6625_read_byte(it6625, REG_VID_INFO);
+	if (val < 0) {
+		dev_err(it6625->dev, "failed to read video info");
+		return -EIO;
+	}
+
+	bt->interlaced = val & B_INTERLACE ?
+			 V4L2_DV_INTERLACED : V4L2_DV_PROGRESSIVE;
+
+	if (it6625_read_bytes(it6625, REG_H_ACTIVE_1, buffer, 8) < 0)
+		return -EIO;
+
+	width = ((buffer[0] & 0xff) << 8) + buffer[1];
+	height = ((buffer[2] & 0xff) << 8) + buffer[3];
+	frame_width = ((buffer[4] & 0xff) << 8) + buffer[5];
+	frame_height = ((buffer[6] & 0xff) << 8) + buffer[7];
+
+	bt->width = width;
+	bt->height = height;
+	bt->vsync = frame_height - height;
+	bt->hsync = frame_width - width;
+
+	bt->pixelclock = it6625_get_pclk(it6625);
+	if (bt->interlaced == V4L2_DV_INTERLACED) {
+		bt->height *= 2;
+		bt->il_vsync = bt->vsync + 1;
+		bt->pixelclock /= 2;
+	}
+
+	return 0;
+}
+
+static void it6625_show_avi_infoframe(struct it6625 *it6625)
+{
+	struct device *dev = it6625->dev;
+	union hdmi_infoframe frame;
+	u8 buffer[HDMI_INFOFRAME_SIZE(AVI)];
+	u8 ver, len;
+	int ret;
+
+	if (!is_hdmi(it6625)) {
+		dev_err(dev, "not HDMI signal, skip AVI infoframe log");
+		return;
+	}
+
+	ret = it6625_read_bytes(it6625, REG_AVI_DATA, buffer + 1,
+				HDMI_INFOFRAME_SIZE(AVI) - 1);
+	if (ret < 0) {
+		dev_err(dev, "failed to read AVI infoframe data");
+		return;
+	}
+
+	len = buffer[1];
+	ver = buffer[2];
+
+	buffer[0] = HDMI_INFOFRAME_TYPE_AVI;
+	buffer[1] = ver;
+	buffer[2] = len;
+
+	ret = hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer));
+	if (ret < 0) {
+		dev_err(dev, "unpack of AVI infoframe failed");
+		return;
+	}
+
+	hdmi_infoframe_log(KERN_INFO, dev, &frame);
+}
+
+static int it6625_s_ctrl_detect_hdmi_5v(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	return v4l2_ctrl_s_ctrl(it6625->ctrl_5v_detect,
+				hdmi_5v_power_present(it6625));
+}
+
+static int it6625_s_ctrl_audio_sampling_rate(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	return v4l2_ctrl_s_ctrl(it6625->ctrl_audio_sampling_rate,
+				get_audio_sampling_rate(it6625));
+}
+
+static int it6625_s_ctrl_audio_present(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	return v4l2_ctrl_s_ctrl(it6625->ctrl_audio_present,
+				audio_present(it6625));
+}
+
+static int it6625_v4l2_sd_ctrl_update(struct v4l2_subdev *sd)
+{
+	int ret = 0;
+
+	ret |= it6625_s_ctrl_detect_hdmi_5v(sd);
+	ret |= it6625_s_ctrl_audio_sampling_rate(sd);
+	ret |= it6625_s_ctrl_audio_present(sd);
+
+	return 0;
+}
+
+static void it6625_enable_stream(struct it6625 *it6625, bool enable)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	int val;
+
+	v4l2_dbg(3, debug, sd, "%s: %sable",
+		 __func__, enable ? "en" : "dis");
+
+	val = enable ? B_MIPI_OUTPUT : 0;
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_set_bits(it6625, REG_MIPI_CONTROL, B_MIPI_OUTPUT, val);
+	it6625_update_config(it6625);
+}
+
+static void it6625_set_mipi_config(struct it6625 *it6625, u32 cfg_val)
+{
+	u8 mipi_data_type;
+
+	dev_dbg(it6625->dev, "mipi_data_type = 0x%x", cfg_val);
+
+	mipi_data_type = cfg_val & 0xFF;
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_write_byte(it6625, REG_MIPI_DATA_TYPE, mipi_data_type);
+	it6625_update_config(it6625);
+}
+
+static inline unsigned int fps_from_bt_timings(const struct v4l2_bt_timings *t)
+{
+	if (!V4L2_DV_BT_FRAME_HEIGHT(t) || !V4L2_DV_BT_FRAME_WIDTH(t))
+		return 0;
+
+	return DIV_ROUND_CLOSEST((unsigned int)t->pixelclock,
+				 V4L2_DV_BT_FRAME_HEIGHT(t) *
+				 V4L2_DV_BT_FRAME_WIDTH(t));
+}
+
+static void it6625_initial_setup(struct it6625 *it6625)
+{
+	int val = 0;
+
+	/*
+	 * REG_MIPI_CFG[0:2] lane count field: 1 lane -> 0, 2 lanes -> 1,
+	 * 3 lanes (C-PHY only) -> 3, 4 lanes (D-PHY only) -> 3.
+	 */
+	switch (it6625->csi_lanes) {
+	case 1:
+		val = FIELD_PREP(M_MIPI_LANE, 0);
+		break;
+	case 2:
+		val = FIELD_PREP(M_MIPI_LANE, 1);
+		break;
+	default:
+		val = FIELD_PREP(M_MIPI_LANE, 3);
+		break;
+	}
+
+	if (it6625->bus_type == V4L2_MBUS_CSI2_DPHY)
+		val |= FIELD_PREP(B_MIPI_DPHY, 1);
+
+	if (it6625->port_num == 2)
+		val |= FIELD_PREP(B_MIPI_SPLIT, 1);
+
+	it6625_write_byte(it6625, REG_MIPI_CFG, val);
+	it6625_write_byte(it6625, REG_MIPI_DATA_TYPE, it6625->csi_format);
+	it6625_write_byte(it6625, REG_MIPI_CONTROL, 0x00);
+	it6625_write_byte(it6625, REG_RX_CFG, 0x00);
+
+	/*trigger FW start*/
+	it6625_set_bits(it6625, REG_CHIP_CONTROL, B_FW_START, B_FW_START);
+	it6625_set_bits(it6625, REG_HOST_CTRL_INT, B_CONFIG_UPDATE, B_CONFIG_UPDATE);
+	it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+}
+
+static void dump_cec_msg(struct it6625 *it6625, struct cec_msg *msg, char *str)
+{
+	int i;
+
+	dev_dbg(it6625->dev, "%s: from %d to %d len=%d", str,
+		msg->msg[0] >> 4, msg->msg[0] & 0x0f, msg->len);
+	for (i = 1; i < msg->len; i++)
+		dev_dbg(it6625->dev, " %02x", msg->msg[i]);
+}
+
+static int it6625_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct it6625 *it6625 = adap->priv;
+	u8 cmds[2];
+
+	cmds[0] = CMD_SET_CEC_ENABLE;
+	cmds[1] = enable ? 1 : 0;
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_write_command(it6625, cmds, sizeof(cmds));
+
+	return 0;
+}
+
+static int it6625_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
+{
+	struct it6625 *it6625 = adap->priv;
+
+	dev_dbg(it6625->dev, "%s: la=%d", __func__, log_addr);
+
+	if (log_addr != CEC_LOG_ADDR_INVALID) {
+		u8 cmds[2] = {CMD_SET_CEC_LA, log_addr};
+
+		guard(mutex)(&it6625->it6625_lock);
+		it6625_write_command(it6625, cmds, sizeof(cmds));
+	}
+
+	return 0;
+}
+
+static int it6625_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+				    u32 signal_free_time, struct cec_msg *msg)
+{
+	struct it6625 *it6625 = adap->priv;
+
+	dump_cec_msg(it6625, msg, "CEC_TX");
+
+	guard(mutex)(&it6625->it6625_lock);
+	it6625_write_bytes(it6625, REG_CEC_TX_DATA, msg->msg, msg->len);
+	it6625_write_byte(it6625, REG_CEC_TX_DATA_LEN, msg->len);
+	it6625_set_bits(it6625, REG_HOST_CTRL_INT, B_CEC_SEND_DATA, B_CEC_SEND_DATA);
+	it6625_wait_for_status(it6625, REG_HOST_CTRL_INT, 0x00, 25);
+
+	return 0;
+}
+
+static const struct cec_adap_ops it6625_cec_adap_ops = {
+	.adap_enable = it6625_cec_adap_enable,
+	.adap_log_addr = it6625_cec_adap_log_addr,
+	.adap_transmit = it6625_cec_adap_transmit,
+};
+
+static void it6625_cec_handler(struct it6625 *it6625, u8 intstatus)
+{
+	struct cec_msg rxmsg = {};
+	int val = 0;
+
+	if (intstatus & B_CEC_RX_RECEIVED) {
+		val = it6625_read_byte(it6625, REG_CEC_RX_DATA_LEN);
+		if (val <= 0 || val > 16) {
+			dev_err(it6625->dev, "invalid CEC RX length %d", val);
+			return;
+		}
+
+		scoped_guard(mutex, &it6625->it6625_lock) {
+			it6625_read_bytes(it6625, REG_CEC_RX_DATA, &rxmsg.msg[0], val);
+			it6625_write_byte(it6625, REG_CEC_RX_DATA_LEN, 0);
+		}
+		rxmsg.len = val;
+		cec_received_msg(it6625->cec_adap, &rxmsg);
+		dump_cec_msg(it6625, &rxmsg, "CEC_RX");
+	}
+
+	if (intstatus & B_CEC_TX_UPDATE) {
+		val = it6625_read_byte(it6625, REG_CEC_STATUS);
+		if (val < 0) {
+			dev_err(it6625->dev, "read CEC status failed");
+			return;
+		}
+
+		if (val & BIT(0)) {
+			cec_transmit_attempt_done(it6625->cec_adap,
+						  CEC_TX_STATUS_OK);
+		} else if (val & BIT(1)) {
+			cec_transmit_attempt_done(it6625->cec_adap,
+						  CEC_TX_STATUS_NACK);
+		} else {
+			dev_err(it6625->dev, "unknown CEC status %02X", val);
+			cec_transmit_attempt_done(it6625->cec_adap,
+						  CEC_TX_STATUS_NACK);
+		}
+	}
+}
+
+static void it6625_irq_format_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	struct v4l2_dv_timings timings;
+	const struct v4l2_event it6625_ev_fmt = {
+		.type = V4L2_EVENT_SOURCE_CHANGE,
+		.u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION,
+	};
+	int ret;
+
+	if (no_signal(it6625))
+		return;
+
+	ret = it6625_get_detected_timings(it6625, &timings);
+	if (ret < 0) {
+		v4l2_dbg(1, debug, sd, "Failed to get detected timings");
+		return;
+	}
+
+	if (sd->devnode)
+		v4l2_subdev_notify_event(sd, &it6625_ev_fmt);
+}
+
+static void it6625_irq_hdmi_audio_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+
+	it6625_s_ctrl_audio_sampling_rate(sd);
+	it6625_s_ctrl_audio_present(sd);
+}
+
+static void it6625_get_timings(struct it6625 *it6625,
+			       struct v4l2_dv_timings *timings)
+{
+	guard(mutex)(&it6625->it6625_lock);
+	*timings = it6625->timings;
+}
+
+static void it6625_clear_timings(struct it6625 *it6625)
+{
+	guard(mutex)(&it6625->it6625_lock);
+	memset(&it6625->timings, 0, sizeof(it6625->timings));
+}
+
+static void it6625_irq_hdmi_5v_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+
+	it6625_clear_timings(it6625);
+	it6625_v4l2_sd_ctrl_update(sd);
+}
+
+static void it6625_irq_hdcp_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	u8 cp_sts;
+
+	cp_sts = it6625_read_byte(it6625, REG_RX_HDCP_STS);
+	v4l2_info(sd, "HDCP change to %02X", cp_sts);
+}
+
+static void it6625_irq_infoframe_latch(struct it6625 *it6625)
+{
+	u8 info_frame[32];
+
+	it6625_read_bytes(it6625, REG_IF_DATA, info_frame, 31);
+}
+
+static void it6625_irq_emata_packet_latch(struct it6625 *it6625)
+{
+	u8 extend_packet[14];
+
+	it6625_read_bytes(it6625, REG_EMP_DATA, extend_packet, 13);
+}
+
+static void it6625_irq_avmute_change(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	int val;
+	u8 avmute;
+
+	val = it6625_read_byte(it6625, REG_RX_STATUS);
+	if (val < 0)
+		return;
+
+	avmute = (val & B_RX_AVMUTE) ? 1 : 0;
+	v4l2_info(sd, "AVMute change to %d", avmute);
+}
+
+static int it6625_interrupt_handler(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	int val, int_sts1 = 0, int_sts2 = 0;
+
+	val = it6625_read_byte(it6625, REG_MCU_INTERRUPT);
+	if (val <= 0)
+		return 0;
+
+	it6625_write_byte(it6625, REG_MCU_INTERRUPT, val);
+
+	v4l2_dbg(1, debug, sd, "%s: INT = 0x%02X", __func__, val);
+
+	if (val & (B_CEC_RX_RECEIVED | B_CEC_TX_UPDATE) && it6625->cec_adap)
+		it6625_cec_handler(it6625, val & (B_CEC_RX_RECEIVED | B_CEC_TX_UPDATE));
+
+	if (val & B_SYS_INT_ACTIVE) {
+		int_sts1 = it6625_read_byte(it6625, REG_RX_INT_STATUS1);
+		int_sts2 = it6625_read_byte(it6625, REG_RX_INT_STATUS2);
+		v4l2_dbg(1, debug, sd, "%s: hdmi_int = 0x%02X 0x%02X",
+			 __func__, int_sts1, int_sts2);
+
+		if (int_sts1 >= 0) {
+			it6625_write_byte(it6625, REG_RX_INT_STATUS1, 0x00);
+			if (int_sts1 & B_HDMI_5V_CHG)
+				it6625_irq_hdmi_5v_change(it6625);
+
+			if (int_sts1 & B_HDMI_VID_CHG)
+				it6625_irq_format_change(it6625);
+
+			if (int_sts1 & B_HDMI_AUD_CHG)
+				it6625_irq_hdmi_audio_change(it6625);
+
+			if (int_sts1 & B_HDMI_CP_CHG)
+				it6625_irq_hdcp_change(it6625);
+
+			if (int_sts1 & B_HDMI_IF_LATCH)
+				it6625_irq_infoframe_latch(it6625);
+
+			if (int_sts1 & B_HDMI_EMP)
+				it6625_irq_emata_packet_latch(it6625);
+		}
+
+		if (int_sts2 >= 0) {
+			it6625_write_byte(it6625, REG_RX_INT_STATUS2, 0x00);
+
+			if (int_sts2 & B_HDMI_AVI)
+				it6625_show_avi_infoframe(it6625);
+
+			if (int_sts2 & B_HDMI_NO_AVI)
+				v4l2_info(sd, "AVI-info stopped");
+
+			if (int_sts2 & B_HDMI_AVMUTE_CHG)
+				it6625_irq_avmute_change(it6625);
+		}
+	}
+
+	return 0;
+}
+
+static irqreturn_t it6625_irq_handler(int unused, void *data)
+{
+	struct it6625 *it6625 = data;
+
+	it6625_interrupt_handler(it6625);
+	return IRQ_HANDLED;
+}
+
+static void it6625_irq_poll_timer(struct timer_list *t)
+{
+	struct it6625 *it6625 = timer_container_of(it6625, t, timer);
+	unsigned int msecs;
+
+	schedule_work(&it6625->polling_work);
+	/*
+	 * If CEC is present, then we need to poll more frequently,
+	 * otherwise we will miss CEC messages.
+	 */
+	msecs = it6625->cec_adap ? POLL_INTERVAL_CEC_MS : POLL_INTERVAL_MS;
+	mod_timer(&it6625->timer, jiffies + msecs_to_jiffies(msecs));
+}
+
+static void it6625_polling_work(struct work_struct *work)
+{
+	struct it6625 *it6625 = container_of(work, struct it6625,
+					polling_work);
+
+	it6625_interrupt_handler(it6625);
+}
+
+static int it6625_log_status(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	struct v4l2_dv_timings timings, configured_timings;
+
+	if (it6625_get_detected_timings(it6625, &timings))
+		v4l2_info(sd, "No video detected");
+	else
+		v4l2_print_dv_timings(sd->name, "Detected format: ", &timings,
+				      true);
+
+	it6625_get_timings(it6625, &configured_timings);
+	v4l2_print_dv_timings(sd->name, "Configured format: ",
+			      &configured_timings, true);
+
+	it6625_show_avi_infoframe(it6625);
+
+	return 0;
+}
+
+static int it6625_isr(struct v4l2_subdev *sd, u32 status, bool *handled)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	schedule_work(&it6625->polling_work);
+	*handled = true;
+
+	return 0;
+}
+
+static int it6625_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
+				  struct v4l2_event_subscription *sub)
+{
+	switch (sub->type) {
+	case V4L2_EVENT_SOURCE_CHANGE:
+		return v4l2_src_change_event_subdev_subscribe(sd, fh, sub);
+	case V4L2_EVENT_CTRL:
+		return v4l2_ctrl_subdev_subscribe_event(sd, fh, sub);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int it6625_g_input_status(struct v4l2_subdev *sd, u32 *status)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	bool val;
+
+	val = no_signal(it6625);
+	*status = 0;
+	*status |= val ? V4L2_IN_ST_NO_SIGNAL : 0;
+	*status |= val ? V4L2_IN_ST_NO_SYNC : 0;
+
+	v4l2_dbg(1, debug, sd, "%s: status = 0x%x", __func__, *status);
+
+	return 0;
+}
+
+static int
+it6625_update_timings_if_changed(struct it6625 *it6625,
+				 const struct v4l2_dv_timings *timings)
+{
+	int ret;
+
+	guard(mutex)(&it6625->it6625_lock);
+	if (v4l2_match_dv_timings(&it6625->timings, timings, 0, false)) {
+		ret = 0;
+	} else if (!v4l2_valid_dv_timings(timings, &it6625_timings_cap,
+					  NULL, NULL)) {
+		ret = -ERANGE;
+	} else {
+		it6625->timings = *timings;
+		ret = 1;
+	}
+
+	return ret;
+}
+
+static int it6625_s_dv_timings(struct v4l2_subdev *sd,
+			       struct v4l2_dv_timings *timings)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int ret;
+
+	if (!timings)
+		return -EINVAL;
+
+	if (debug)
+		v4l2_print_dv_timings(sd->name, __func__, timings, false);
+
+	ret = it6625_update_timings_if_changed(it6625, timings);
+	if (ret == -ERANGE) {
+		v4l2_dbg(1, debug, sd, "%s: timings out of range", __func__);
+		return ret;
+	}
+
+	if (ret == 0) {
+		v4l2_dbg(1, debug, sd, "%s: no change", __func__);
+		return 0;
+	}
+
+	it6625_enable_stream(it6625, false);
+
+	return 0;
+}
+
+static int it6625_g_dv_timings(struct v4l2_subdev *sd,
+			       struct v4l2_dv_timings *timings)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	it6625_get_timings(it6625, timings);
+
+	return 0;
+}
+
+static int it6625_enum_dv_timings(struct v4l2_subdev *sd,
+				  struct v4l2_enum_dv_timings *timings)
+{
+	if (timings->pad != 0)
+		return -EINVAL;
+
+	return v4l2_enum_dv_timings_cap(timings,
+					&it6625_timings_cap, NULL, NULL);
+}
+
+static int it6625_query_dv_timings(struct v4l2_subdev *sd,
+				   struct v4l2_dv_timings *timings)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int ret;
+
+	ret = it6625_get_detected_timings(it6625, timings);
+	if (ret)
+		return ret;
+
+	if (debug)
+		v4l2_print_dv_timings(sd->name, __func__, timings, false);
+
+	if (!v4l2_valid_dv_timings(timings, &it6625_timings_cap, NULL, NULL)) {
+		v4l2_dbg(1, debug, sd, "%s: timings out of range", __func__);
+		return -ERANGE;
+	}
+
+	return 0;
+}
+
+static int it6625_dv_timings_cap(struct v4l2_subdev *sd,
+				 struct v4l2_dv_timings_cap *cap)
+{
+	if (cap->pad != 0)
+		return -EINVAL;
+
+	*cap = it6625_timings_cap;
+
+	return 0;
+}
+
+static int it6625_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	it6625_enable_stream(it6625, enable);
+	return 0;
+}
+
+static int it6625_enum_mbus_code(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_state *sd_state,
+				 struct v4l2_subdev_mbus_code_enum *code)
+{
+	dev_dbg(sd->dev, "%s: index=%d", __func__, code->index);
+
+	if (code->index >= ARRAY_SIZE(it6625_formats))
+		return -EINVAL;
+
+	dev_dbg(sd->dev, "%s: code=0x%08x", __func__,
+		it6625_formats[code->index].mbus_fmt_code);
+	code->code = it6625_formats[code->index].mbus_fmt_code;
+
+	return 0;
+}
+
+static int it6625_get_mbus_config(struct v4l2_subdev *sd,
+				  unsigned int pad,
+				  struct v4l2_mbus_config *cfg)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	if (pad != 0)
+		return -EINVAL;
+
+	cfg->type = it6625->bus_type;
+	cfg->bus.mipi_csi2.flags = 0;
+	cfg->bus.mipi_csi2.num_data_lanes = it6625->csi_lanes;
+
+	return 0;
+}
+
+static int it6625_pad_s_dv_timings(struct v4l2_subdev *sd, unsigned int pad,
+				   struct v4l2_dv_timings *timings)
+{
+	if (pad != 0)
+		return -EINVAL;
+
+	return it6625_s_dv_timings(sd, timings);
+}
+
+static int it6625_pad_g_dv_timings(struct v4l2_subdev *sd, unsigned int pad,
+				   struct v4l2_dv_timings *timings)
+{
+	if (pad != 0)
+		return -EINVAL;
+
+	return it6625_g_dv_timings(sd, timings);
+}
+
+static int it6625_pad_query_dv_timings(struct v4l2_subdev *sd,
+				       unsigned int pad,
+				       struct v4l2_dv_timings *timings)
+{
+	if (pad != 0)
+		return -EINVAL;
+
+	return it6625_query_dv_timings(sd, timings);
+}
+
+static inline u32 format_to_colorspace(u8 csi_format)
+{
+	switch (csi_format) {
+	case CSI_RGB444:
+	case CSI_RGB555:
+	case CSI_RGB565:
+	case CSI_RGB666:
+	case CSI_RGB888:
+	case CSI_RGB_10b:
+	case CSI_RGB_12b:
+		return V4L2_COLORSPACE_SRGB;
+	case CSI_YUV420_8b_L:
+	case CSI_YUV420_8b:
+	case CSI_YUV420_10b:
+	case CSI_YUV422_8b:
+	case CSI_YUV422_10b:
+	case CSI_YUV422_12b:
+	case CSI_YUV420_10b_L:
+	case CSI_YUV420_12b:
+	case CSI_YUV444_8b:
+	case CSI_YUV444_10b:
+	case CSI_YUV444_12b:
+		return V4L2_COLORSPACE_REC709;
+	default:
+		return 0;
+	}
+}
+
+static int it6625_get_fmt(struct v4l2_subdev *sd,
+			  struct v4l2_subdev_state *sd_state,
+			  struct v4l2_subdev_format *format)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	struct v4l2_dv_timings timings;
+
+	if (format->pad != 0)
+		return -EINVAL;
+
+	format->format.code = it6625->mbus_fmt_code;
+	it6625_get_timings(it6625, &timings);
+	format->format.width = timings.bt.width;
+	format->format.height = timings.bt.height;
+	format->format.colorspace = format_to_colorspace(it6625->csi_format);
+	format->format.field = timings.bt.interlaced == V4L2_DV_INTERLACED ?
+			       V4L2_FIELD_INTERLACED : V4L2_FIELD_NONE;
+
+	return 0;
+}
+
+static int it6625_set_fmt(struct v4l2_subdev *sd,
+			  struct v4l2_subdev_state *sd_state,
+			  struct v4l2_subdev_format *format)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int ret;
+	u32 mbus_fmt_code = format->format.code;
+
+	ret = it6625_get_fmt(sd, sd_state, format);
+	format->format.code = mbus_fmt_code;
+
+	if (ret)
+		return ret;
+
+	ret = it6625_csi_mbus_code_idx(mbus_fmt_code);
+
+	if (ret < 0) {
+		v4l2_dbg(1, debug, sd, "%s: unsupported format code 0x%x",
+			 __func__, mbus_fmt_code);
+		return ret;
+	}
+
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
+		v4l2_dbg(1, debug, sd, "%s: try format code = 0x%x",
+			 __func__, format->format.code);
+		return 0;
+	}
+
+	it6625->csi_format = it6625_formats[ret].csi_format;
+	it6625->mbus_fmt_code = format->format.code;
+	it6625_enable_stream(it6625, false);
+	it6625_set_mipi_config(it6625, it6625->csi_format);
+
+	return 0;
+}
+
+static int it6625_g_edid(struct v4l2_subdev *sd,
+			 struct v4l2_subdev_edid *edid)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int err;
+
+	if (edid->pad != 0)
+		return -EINVAL;
+
+	memset(edid->reserved, 0, sizeof(edid->reserved));
+
+	if (edid->blocks == 0) {
+		edid->blocks = EDID_NUM_BLOCKS_MAX;
+		return 0;
+	}
+
+	err = it6625_read_edid(it6625, edid->edid, edid->start_block,
+			       edid->blocks);
+
+	return (err < 0) ? err : 0;
+}
+
+static int it6625_s_edid(struct v4l2_subdev *sd,
+			 struct v4l2_subdev_edid *edid)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	int err;
+	u16 pa;
+
+	if (edid->pad != 0) {
+		v4l2_err(sd, "invalid pad %d", edid->pad);
+		return -EINVAL;
+	}
+
+	memset(edid->reserved, 0, sizeof(edid->reserved));
+
+	it6625_disable_hpd(it6625);
+
+	if (edid->blocks != 0) {
+		err = it6625_write_edid(it6625, edid->edid,
+					edid->start_block, edid->blocks);
+		if (err) {
+			v4l2_err(sd, "write edid failed");
+			return err;
+		}
+	}
+
+	pa = cec_get_edid_phys_addr(edid->edid, edid->blocks * 128, NULL);
+	if (pa == CEC_PHYS_ADDR_INVALID) {
+		v4l2_warn(sd, "invalid CEC physical address in EDID");
+		cec_phys_addr_invalidate(it6625->cec_adap);
+	} else {
+		v4l2_phys_addr_validate(pa, NULL, NULL);
+		cec_s_phys_addr(it6625->cec_adap, pa, false);
+	}
+
+	if (hdmi_5v_power_present(it6625)) {
+		it6625_enable_hpd(it6625);
+		it6625_s_ctrl_detect_hdmi_5v(sd);
+	} else {
+		it6625_enable_auto_hpd(it6625);
+	}
+
+	return 0;
+}
+
+#define V4L2_CID_USER_IT6625_BASE	(V4L2_CID_USER_BASE + 0x11b0)
+#define IT6625_CID_AUDIO_SAMPLING_RATE  (V4L2_CID_USER_IT6625_BASE + 0)
+#define IT6625_CID_AUDIO_PRESENT        (V4L2_CID_USER_IT6625_BASE + 1)
+#define IT6625_CID_HDMI_INFO            (V4L2_CID_USER_IT6625_BASE + 2)
+#define IT6625_CID_MIPI_CONFIG          (V4L2_CID_USER_IT6625_BASE + 3)
+static int it6625_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct it6625 *it6625 = hdl_to_6625(ctrl->handler);
+	struct v4l2_subdev *sd = &it6625->sd;
+
+	v4l2_dbg(1, debug, sd, "%s, id=0x%x, val=%d",
+		 __func__, ctrl->id, ctrl->val);
+
+	switch (ctrl->id) {
+	case IT6625_CID_HDMI_INFO:
+		snprintf(ctrl->p_new.p_char, ctrl->maximum,
+			 "RGB444 10bit @ 60Hz");
+		break;
+	case IT6625_CID_MIPI_CONFIG:
+		ctrl->val = it6625_read_byte(it6625, REG_MIPI_DATA_TYPE);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int it6625_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct it6625 *it6625 = hdl_to_6625(ctrl->handler);
+	struct v4l2_subdev *sd = &it6625->sd;
+
+	v4l2_dbg(1, debug, sd, "%s, id=0x%x, val=%d",
+		 __func__, ctrl->id, ctrl->val);
+
+	switch (ctrl->id) {
+	case IT6625_CID_MIPI_CONFIG:
+		it6625_set_mipi_config(it6625, ctrl->val);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct v4l2_subdev_core_ops it6625_core_ops = {
+	.log_status = it6625_log_status,
+	.interrupt_service_routine = it6625_isr,
+	.subscribe_event = it6625_subscribe_event,
+	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
+};
+
+static const struct v4l2_subdev_video_ops it6625_video_ops = {
+	.g_input_status = it6625_g_input_status,
+	.s_stream = it6625_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops it6625_pad_ops = {
+	.enum_mbus_code = it6625_enum_mbus_code,
+	.set_fmt = it6625_set_fmt,
+	.get_fmt = it6625_get_fmt,
+	.get_edid = it6625_g_edid,
+	.set_edid = it6625_s_edid,
+	.enum_dv_timings = it6625_enum_dv_timings,
+	.dv_timings_cap = it6625_dv_timings_cap,
+	.get_mbus_config = it6625_get_mbus_config,
+	.s_dv_timings = it6625_pad_s_dv_timings,
+	.g_dv_timings = it6625_pad_g_dv_timings,
+	.query_dv_timings = it6625_pad_query_dv_timings,
+};
+
+static const struct v4l2_subdev_ops it6625_ops = {
+	.core = &it6625_core_ops,
+	.video = &it6625_video_ops,
+	.pad = &it6625_pad_ops,
+};
+
+static const struct v4l2_ctrl_ops it6625_ctrl_ops = {
+	.g_volatile_ctrl = it6625_g_volatile_ctrl,
+	.s_ctrl = it6625_s_ctrl,
+};
+
+static const struct v4l2_ctrl_config it6625_ctrl_audio_sampling_rate = {
+	.id = IT6625_CID_AUDIO_SAMPLING_RATE,
+	.name = "Audio sampling rate",
+	.type = V4L2_CTRL_TYPE_INTEGER,
+	.min = 0,
+	.max = 768000,
+	.step = 1,
+	.def = 0,
+	.flags = V4L2_CTRL_FLAG_READ_ONLY,
+};
+
+static const struct v4l2_ctrl_config it6625_ctrl_audio_present = {
+	.id = IT6625_CID_AUDIO_PRESENT,
+	.name = "Audio present",
+	.type = V4L2_CTRL_TYPE_BOOLEAN,
+	.min = 0,
+	.max = 1,
+	.step = 1,
+	.def = 0,
+	.flags = V4L2_CTRL_FLAG_READ_ONLY,
+};
+
+static const struct v4l2_ctrl_config it6625_ctrl_get_hdmi_info = {
+	.ops = &it6625_ctrl_ops,
+	.id = IT6625_CID_HDMI_INFO,
+	.name = "HDMI Info",
+	.type = V4L2_CTRL_TYPE_STRING,
+	.max = 128,
+	.step = 1,
+	.flags = V4L2_CTRL_FLAG_READ_ONLY,
+};
+
+static const struct v4l2_ctrl_config it6625_ctrl_mipi_config = {
+	.ops = &it6625_ctrl_ops,
+	.id = IT6625_CID_MIPI_CONFIG,
+	.name = "MIPI config",
+	.type = V4L2_CTRL_TYPE_INTEGER,
+	.min = 0,
+	.max = 0x7FFFFFFF,
+	.step = 1,
+	.def = 0x3E,
+	.flags = V4L2_CTRL_FLAG_VOLATILE,
+};
+
+static int it6625_v4l2_init_controls(struct v4l2_subdev *sd)
+{
+	struct it6625 *it6625 = sd_to_6625(sd);
+	struct v4l2_ctrl_handler *hdl = &it6625->hdl;
+
+	v4l2_ctrl_handler_init(hdl, 4);
+	it6625->ctrl_5v_detect =
+		v4l2_ctrl_new_std(hdl, NULL, V4L2_CID_DV_RX_POWER_PRESENT,
+				  0, 1, 0, 0);
+
+	it6625->ctrl_audio_sampling_rate =
+		v4l2_ctrl_new_custom(hdl,
+				     &it6625_ctrl_audio_sampling_rate,
+				     NULL);
+	it6625->ctrl_audio_present =
+		v4l2_ctrl_new_custom(hdl, &it6625_ctrl_audio_present, NULL);
+	it6625->ctrl_link_freq =
+		v4l2_ctrl_new_int_menu(hdl, NULL, V4L2_CID_LINK_FREQ,
+				       ARRAY_SIZE(it6625_link_freq) - 1,
+				       0, it6625_link_freq);
+	it6625->ctrl_get_hdmi_info =
+		v4l2_ctrl_new_custom(hdl, &it6625_ctrl_get_hdmi_info, NULL);
+	it6625->ctrl_mipi_config =
+		v4l2_ctrl_new_custom(hdl, &it6625_ctrl_mipi_config, NULL);
+	if (hdl->error) {
+		v4l2_err(sd, "Failed to initialize controls");
+		v4l2_ctrl_handler_free(hdl);
+		return hdl->error;
+	}
+
+	sd->ctrl_handler = hdl;
+
+	return 0;
+}
+
+static void it6625_regdump_print(struct seq_file *s, const u8 *reg_buf)
+{
+	int i;
+
+	seq_puts(s, "     0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C 0x0D 0x0E 0x0F\n");
+
+	for (i = 0; i < 256; i++) {
+		if (i % 16 == 0)
+			seq_printf(s, "[%02X] ", i & 0xF0);
+		seq_printf(s, "0x%02X ", reg_buf[i]);
+		if (i % 16 == 15)
+			seq_putc(s, '\n');
+	}
+}
+
+static int it6625_edid_ram_show(struct seq_file *s, void *data)
+{
+	struct it6625 *it6625 = s->private;
+	u8 reg_buf[256];
+
+	it6625_read_edid(it6625, reg_buf, 0, 2);
+	it6625_regdump_print(s, reg_buf);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(it6625_edid_ram);
+
+static int it6625_mipi_reg_show(struct seq_file *s, void *data)
+{
+	struct it6625 *it6625 = s->private;
+	u8 reg_buf[256];
+
+	it6625_read_bytes(it6625, 0x00, reg_buf, sizeof(reg_buf));
+	it6625_regdump_print(s, reg_buf);
+
+	return 0;
+}
+
+static int it6625_mipi_reg_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, it6625_mipi_reg_show, inode->i_private);
+}
+
+static ssize_t it6625_mipi_reg_write(struct file *file,
+				     const char __user *user_buf,
+				     size_t count, loff_t *ppos)
+{
+	struct it6625 *it6625 = file_inode(file)->i_private;
+	char buf[32] = {};
+	unsigned int addr, val;
+	ssize_t len;
+
+	len = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count);
+	if (len < 0)
+		return len;
+	buf[len] = '\0';
+
+	if (sscanf(buf, "%X %X", &addr, &val) != 2)
+		return -EINVAL;
+
+	it6625_write_byte(it6625, addr, val);
+
+	return count;
+}
+
+static const struct file_operations it6625_mipi_reg_fops = {
+	.owner = THIS_MODULE,
+	.open = it6625_mipi_reg_open,
+	.read = seq_read,
+	.write = it6625_mipi_reg_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static void it6625_debugfs_init(struct it6625 *it6625, struct i2c_client *client)
+{
+	it6625->debugfs_dir = debugfs_create_dir(dev_name(&client->dev), NULL);
+
+	debugfs_create_file("mipi_reg", 0600, it6625->debugfs_dir, it6625,
+			    &it6625_mipi_reg_fops);
+	debugfs_create_file("edid_ram", 0400, it6625->debugfs_dir, it6625,
+			    &it6625_edid_ram_fops);
+}
+
+static void it6625_init_data(struct it6625 *it6625)
+{
+	static struct v4l2_dv_timings default_timing =
+			V4L2_DV_BT_CEA_1920X1080P60;
+
+	it6625->csi_lanes = 4;
+	it6625->port_num = 1;
+	it6625->bus_type = V4L2_MBUS_CSI2_DPHY;
+	it6625->csi_format = it6625_formats[0].csi_format;
+	it6625->mbus_fmt_code = it6625_formats[0].mbus_fmt_code;
+	it6625->timings = default_timing;
+}
+
+static int it6625_parse_endpoint(struct it6625 *it6625)
+{
+	struct device *dev = it6625->dev;
+	struct v4l2_fwnode_endpoint endpoint = { .bus_type = V4L2_MBUS_CSI2_DPHY };
+	struct device_node *ep = NULL;
+	unsigned int max_lanes;
+	unsigned int port;
+	int ret;
+
+	/*
+	 * port@0 and port@1 are the two CSI-2 output ports MIPI0/MIPI1
+	 * (port@2 is the HDMI input). This chip series can drive both
+	 * simultaneously in split or mirror mode, so port_num counts how
+	 * many of MIPI0/MIPI1 have an endpoint wired up. This driver only
+	 * wires up a single source pad, so lane/bus-type configuration is
+	 * parsed from whichever of the two is found first.
+	 */
+	it6625->port_num = 0;
+	for (port = 0; port < 2; port++) {
+		struct device_node *port_ep =
+			of_graph_get_endpoint_by_regs(dev->of_node, port, -1);
+
+		if (!port_ep)
+			continue;
+
+		it6625->port_num++;
+		if (!ep)
+			ep = port_ep;
+		else
+			of_node_put(port_ep);
+	}
+
+	if (!ep) {
+		it6625->port_num = 1;
+		dev_dbg(dev, "no CSI-2 endpoint node found, using default %u CSI lanes",
+			it6625->csi_lanes);
+		return 0;
+	}
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(of_fwnode_handle(ep), &endpoint);
+	of_node_put(ep);
+	if (ret) {
+		dev_err(dev, "failed to parse endpoint: %d", ret);
+		return ret;
+	}
+
+	if (endpoint.bus_type == V4L2_MBUS_CSI2_CPHY &&
+	    it6625->chip_type != IT6626_CHIP) {
+		dev_err(dev, "IT6625 does not support C-PHY, only IT6626 does");
+		v4l2_fwnode_endpoint_free(&endpoint);
+		return -EINVAL;
+	}
+
+	max_lanes = (endpoint.bus_type == V4L2_MBUS_CSI2_CPHY) ? 3 : 4;
+
+	if (endpoint.bus.mipi_csi2.num_data_lanes == 0 ||
+	    endpoint.bus.mipi_csi2.num_data_lanes > max_lanes) {
+		dev_err(dev,
+			"invalid number of CSI data lanes: %u (max %u for this bus type)",
+			endpoint.bus.mipi_csi2.num_data_lanes, max_lanes);
+		v4l2_fwnode_endpoint_free(&endpoint);
+		return -EINVAL;
+	}
+
+	it6625->csi_lanes = endpoint.bus.mipi_csi2.num_data_lanes;
+	it6625->bus_type = endpoint.bus_type;
+	v4l2_fwnode_endpoint_free(&endpoint);
+
+	return 0;
+}
+
+static int it6625_parse_dt(struct it6625 *it6625)
+{
+	return it6625_parse_endpoint(it6625);
+}
+
+static int it6625_init_v4l2_subdev(struct it6625 *it6625)
+{
+	struct v4l2_subdev *sd = &it6625->sd;
+	int err;
+
+	sd->dev = it6625->dev;
+
+	v4l2_i2c_subdev_init(sd, it6625->i2c_client, &it6625_ops);
+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
+	if (it6625_v4l2_init_controls(sd)) {
+		dev_err(it6625->dev, "Failed to initialize v4l2 controls");
+		return -ENOMEM;
+	}
+
+	it6625->pad.flags = MEDIA_PAD_FL_SOURCE;
+	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
+	err = media_entity_pads_init(&sd->entity, 1, &it6625->pad);
+	if (err < 0) {
+		dev_err(it6625->dev, "%s %d err=%d", __func__, __LINE__, err);
+		v4l2_ctrl_handler_free(sd->ctrl_handler);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6625_check_device(struct it6625 *it6625)
+{
+	static const u8 chip_ids[][2] = {
+		{ 0x66, 0x25 },
+		{ 0x66, 0x26 },
+	};
+	int chip_id0, chip_id1;
+
+	chip_id0 = it6625_read_byte(it6625, REG_CHIP_ID_0);
+	chip_id1 = it6625_read_byte(it6625, REG_CHIP_ID_1);
+	if (chip_id0 != chip_ids[it6625->chip_type][0] ||
+	    chip_id1 != chip_ids[it6625->chip_type][1]) {
+		dev_err(it6625->dev,
+			"chip ID mismatch: got 0x%02x%02x, expected 0x%02x%02x",
+			chip_id0, chip_id1,
+			chip_ids[it6625->chip_type][0],
+			chip_ids[it6625->chip_type][1]);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int it6625_probe(struct i2c_client *client)
+{
+	struct it6625 *it6625;
+	struct v4l2_subdev *sd;
+	int err;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -EIO;
+
+	it6625 = devm_kzalloc(&client->dev, sizeof(struct it6625), GFP_KERNEL);
+	if (!it6625)
+		return -ENOMEM;
+
+	it6625->chip_type = (uintptr_t)i2c_get_match_data(client);
+
+	err = it6625_regmap_i2c_init(client, it6625);
+	if (err)
+		return err;
+
+	err = it6625_check_device(it6625);
+	if (err)
+		return err;
+
+	it6625_init_data(it6625);
+
+	err = it6625_parse_dt(it6625);
+	if (err)
+		return err;
+
+	mutex_init(&it6625->it6625_lock);
+	INIT_DELAYED_WORK(&it6625->hpd_delayed_work, it6625_hpd_delayed_work);
+	INIT_WORK(&it6625->polling_work, it6625_polling_work);
+
+	if (client->irq) {
+		err = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, it6625_irq_handler,
+						IRQF_TRIGGER_LOW |
+						IRQF_ONESHOT |
+						IRQF_NO_AUTOEN,
+						"it6625", it6625);
+		if (err)
+			return err;
+	} else {
+		dev_info(it6625->dev, "no IRQ, falling back to polling");
+		timer_setup(&it6625->timer, it6625_irq_poll_timer, 0);
+	}
+
+	sd = &it6625->sd;
+	err = it6625_init_v4l2_subdev(it6625);
+	if (err)
+		goto err_clean_work_queues;
+
+	err = v4l2_ctrl_handler_setup(sd->ctrl_handler);
+	if (err)
+		goto err_clean_hdl;
+
+	it6625->cec_adap = cec_allocate_adapter(&it6625_cec_adap_ops,
+						it6625, dev_name(it6625->dev),
+						CEC_CAP_DEFAULTS |
+						CEC_CAP_MONITOR_ALL |
+						CEC_CAP_PHYS_ADDR,
+						CEC_MAX_LOG_ADDRS);
+	if (IS_ERR(it6625->cec_adap)) {
+		err = PTR_ERR(it6625->cec_adap);
+		dev_err(it6625->dev, "%s %d", __func__, __LINE__);
+		goto err_clean_hdl;
+	}
+
+	err = cec_register_adapter(it6625->cec_adap, &client->dev);
+	if (err < 0) {
+		dev_err(it6625->dev, "%s: failed to register the cec device", __func__);
+		cec_delete_adapter(it6625->cec_adap);
+		it6625->cec_adap = NULL;
+		goto err_clean_hdl;
+	}
+
+	it6625_debugfs_init(it6625, client);
+
+	it6625_initial_setup(it6625);
+	it6625_v4l2_sd_ctrl_update(sd);
+
+	err = v4l2_async_register_subdev(sd);
+	if (err < 0) {
+		dev_err(it6625->dev, "%s %d err=%d", __func__, __LINE__, err);
+		goto err_clean_debugfs;
+	}
+
+	if (client->irq)
+		enable_irq(client->irq);
+	else
+		mod_timer(&it6625->timer, jiffies + msecs_to_jiffies(POLL_INTERVAL_MS));
+
+	return 0;
+
+err_clean_debugfs:
+	debugfs_remove_recursive(it6625->debugfs_dir);
+	cec_unregister_adapter(it6625->cec_adap);
+err_clean_hdl:
+	media_entity_cleanup(&sd->entity);
+	v4l2_ctrl_handler_free(&it6625->hdl);
+
+err_clean_work_queues:
+	if (!client->irq)
+		timer_shutdown_sync(&it6625->timer);
+	cancel_work_sync(&it6625->polling_work);
+	cancel_delayed_work_sync(&it6625->hpd_delayed_work);
+	mutex_destroy(&it6625->it6625_lock);
+	return err;
+}
+
+static void it6625_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct it6625 *it6625 = sd_to_6625(sd);
+
+	v4l2_async_unregister_subdev(sd);
+	v4l2_device_unregister_subdev(sd);
+
+	if (client->irq)
+		disable_irq(client->irq);
+	else
+		timer_shutdown_sync(&it6625->timer);
+
+	cancel_work_sync(&it6625->polling_work);
+	cancel_delayed_work_sync(&it6625->hpd_delayed_work);
+	debugfs_remove_recursive(it6625->debugfs_dir);
+	cec_unregister_adapter(it6625->cec_adap);
+	mutex_destroy(&it6625->it6625_lock);
+	media_entity_cleanup(&sd->entity);
+	v4l2_ctrl_handler_free(&it6625->hdl);
+}
+
+static const struct i2c_device_id it6625_id[] = {
+	{ .name = "it6625", .driver_data = IT6625_CHIP },
+	{ .name = "it6626", .driver_data = IT6626_CHIP },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, it6625_id);
+
+static const struct of_device_id it6625_of_match[] = {
+	{ .compatible = "ite,it6625", .data = (void *)IT6625_CHIP },
+	{ .compatible = "ite,it6626", .data = (void *)IT6626_CHIP },
+	{},
+};
+MODULE_DEVICE_TABLE(of, it6625_of_match);
+
+static struct i2c_driver it6625_driver = {
+	.driver = {
+		.name = "it6625",
+		.of_match_table = of_match_ptr(it6625_of_match),
+	},
+	.probe = it6625_probe,
+	.remove = it6625_remove,
+	.id_table = it6625_id,
+};
+module_i2c_driver(it6625_driver);
+
+MODULE_DESCRIPTION("iTE it6625/it6626 HDMI to MIPI CSI bridge driver");
+MODULE_AUTHOR("Hermes Wu <Hermes.wu@ite.com.tw>");
+MODULE_LICENSE("GPL");

-- 
2.34.1

Re: [PATCH v2 2/2] media: i2c: add driver for ITE IT6625/IT6626

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 11 potential issue(s) to consider:
- [High] Interrupt handler and control paths read banked registers without taking `it6625_lock`, racing with EDID operations and returning corrupted data.
- [High] The driver uses `devm_kzalloc` for its state structure while exposing a V4L2 subdevice node, leading to a Use-After-Free.
- [High] The remove function unregisters the V4L2 subdevice before disabling hardware interrupts, timers, and workqueues, creating a Use-After-Free vulnerability.
- [High] A successful EDID write is incorrectly treated as a failure in `it6625_s_edid()`, skipping initialization.
- [High] Concurrent execution of the `s_edid` IOCTL and `it6625_remove` allows `hpd_delayed_work` to be scheduled after it was canceled, leading to a Use-After-Free.
- [High] Detected timings ignore hardware porch registers, causing V4L2 DV timings matching to fail.
- [Medium] `it6625_get_fmt` and `it6625_set_fmt` ignore `V4L2_SUBDEV_FORMAT_TRY`, breaking format negotiation.
- [Medium] An invalid CEC RX length causes the handler to return early, dropping any simultaneous CEC TX interrupt.
- [Medium] TOCTOU race when reading CEC RX data length truncates CEC messages.
- [Medium] Unprotected modifications to `csi_format` and `mbus_fmt_code` lead to data races.
- [Low] The polling timer callback uses `timer_container_of()`, which does not exist in the Linux kernel.
--

--- Patch [2]: [PATCH v2 2/2] media: i2c: add driver for ITE IT6625/IT6626 ---
commit 34b36b7727e619c34809d9b0bc1a0bc2102491f6
Author: Hermes Wu <Hermes.wu@ite.com.tw>
Subject: media: i2c: add driver for ITE IT6625/IT6626

Add a V4L2 subdevice driver for the ITE IT6625/IT6626 HDMI-to-MIPI
CSI-2 bridge chips. The bridge is configured over I2C, exposes an
HDMI CEC adapter, and supports EDID read/write, DV timings
detection/configuration, and HPD control.

> diff --git a/drivers/media/i2c/it6625.c b/drivers/media/i2c/it6625.c
> index 0000000000000..689739eb3f190
> --- /dev/null
> +++ b/drivers/media/i2c/it6625.c
> @@ -0,0 +1,2104 @@
[ ... ]
> +static int get_audio_sampling_rate(struct it6625 *it6625)
> +{
> +	u8 fs_id;
> +	int i, freq = 0;
[ ... ]
> +	if (no_signal(it6625) || !audio_present(it6625))
> +		return 0;
> +
> +	fs_id = it6625_read_byte(it6625, REG_HDMI_AUDIO_INFO1);

[Severity: High]
Is it possible for this unprotected read of REG_HDMI_AUDIO_INFO1 to race
with an EDID read/write operation that temporarily changes the register bank
via REG_INFO_BANK_SEL? This could result in reading corrupt audio sampling
rates.

> +
> +	for (i = 0; i < ARRAY_SIZE(s_fsid_map); i++) {
[ ... ]
> +static int it6625_get_detected_timings(struct it6625 *it6625,
> +				       struct v4l2_dv_timings *timings)
> +{
> +	struct v4l2_bt_timings *bt = &timings->bt;
[ ... ]
> +	if (it6625_read_bytes(it6625, REG_H_ACTIVE_1, buffer, 8) < 0)
> +		return -EIO;
> +
> +	width = ((buffer[0] & 0xff) << 8) + buffer[1];
> +	height = ((buffer[2] & 0xff) << 8) + buffer[3];
> +	frame_width = ((buffer[4] & 0xff) << 8) + buffer[5];
> +	frame_height = ((buffer[6] & 0xff) << 8) + buffer[7];
> +
> +	bt->width = width;
> +	bt->height = height;
> +	bt->vsync = frame_height - height;
> +	bt->hsync = frame_width - width;

[Severity: High]
Does this logic break V4L2 DV timings matching by ignoring the dedicated
hardware porch registers? 

The v4l2_match_dv_timings function enforces strict equality on all porch
components. Grouping the entire blanking interval into hsync and vsync while
leaving the front and back porches at 0 will prevent matching any standard
CEA/VESA format.

> +
> +	bt->pixelclock = it6625_get_pclk(it6625);
[ ... ]
> +static void it6625_cec_handler(struct it6625 *it6625, u8 intstatus)
> +{
> +	struct cec_msg rxmsg = {};
> +	int val = 0;
> +
> +	if (intstatus & B_CEC_RX_RECEIVED) {
> +		val = it6625_read_byte(it6625, REG_CEC_RX_DATA_LEN);

[Severity: Medium]
Could this lead to a TOCTOU race? The length is read here outside the
it6625_lock. 

If the lock is contended (for example, by an EDID operation), the hardware
might receive more bytes during the wait. Once the lock is acquired below,
the stale smaller length is read, and writing 0 to the length register will
cause the newly arrived bytes to be lost.

> +		if (val <= 0 || val > 16) {
> +			dev_err(it6625->dev, "invalid CEC RX length %d", val);
> +			return;

[Severity: Medium]
Will this early return inadvertently drop a simultaneous CEC TX interrupt if
both B_CEC_RX_RECEIVED and B_CEC_TX_UPDATE are set in intstatus?

> +		}
> +
> +		scoped_guard(mutex, &it6625->it6625_lock) {
[ ... ]
> +static void it6625_irq_format_change(struct it6625 *it6625)
> +{
> +	struct v4l2_subdev *sd = &it6625->sd;
> +	struct v4l2_dv_timings timings;
> +	const struct v4l2_event it6625_ev_fmt = {
> +		.type = V4L2_EVENT_SOURCE_CHANGE,
> +		.u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION,
> +	};
> +	int ret;
> +
> +	if (no_signal(it6625))
> +		return;
> +
> +	ret = it6625_get_detected_timings(it6625, &timings);
> +	if (ret < 0) {
> +		v4l2_dbg(1, debug, sd, "Failed to get detected timings");
> +		return;
> +	}
> +
> +	if (sd->devnode)
> +		v4l2_subdev_notify_event(sd, &it6625_ev_fmt);

[Severity: High]
Is it safe to dereference sd->devnode here if this is called from the
polling workqueue after v4l2_device_unregister_subdev() has been executed in
it6625_remove()? This sequence could result in a use-after-free.

> +}
[ ... ]
> +static void it6625_irq_infoframe_latch(struct it6625 *it6625)
> +{
> +	u8 info_frame[32];
> +
> +	it6625_read_bytes(it6625, REG_IF_DATA, info_frame, 31);

[Severity: High]
Does this read of REG_IF_DATA require the it6625_lock? Without it, a
concurrent EDID operation could switch the register bank, causing this read
to return EDID data instead of the infoframe.

> +}
[ ... ]
> +static void it6625_irq_poll_timer(struct timer_list *t)
> +{
> +	struct it6625 *it6625 = timer_container_of(it6625, t, timer);

[Severity: Low]
Does the timer_container_of macro exist in the kernel? It seems from_timer
should be used here to avoid compilation errors.

> +	unsigned int msecs;
[ ... ]
> +static int it6625_get_fmt(struct v4l2_subdev *sd,
> +			  struct v4l2_subdev_state *sd_state,
> +			  struct v4l2_subdev_format *format)
> +{
> +	struct it6625 *it6625 = sd_to_6625(sd);
> +	struct v4l2_dv_timings timings;
> +
> +	if (format->pad != 0)
> +		return -EINVAL;
> +
> +	format->format.code = it6625->mbus_fmt_code;
> +	it6625_get_timings(it6625, &timings);

[Severity: Medium]
Should this function return the TRY format from sd_state when format->which
is V4L2_SUBDEV_FORMAT_TRY? Returning the active hardware state here ignores
the TRY semantics and breaks format negotiation.

> +	format->format.width = timings.bt.width;
[ ... ]
> +static int it6625_set_fmt(struct v4l2_subdev *sd,
> +			  struct v4l2_subdev_state *sd_state,
> +			  struct v4l2_subdev_format *format)
> +{
> +	struct it6625 *it6625 = sd_to_6625(sd);
> +	int ret;
> +	u32 mbus_fmt_code = format->format.code;
> +
> +	ret = it6625_get_fmt(sd, sd_state, format);
> +	format->format.code = mbus_fmt_code;
> +
> +	if (ret)
> +		return ret;
> +
> +	ret = it6625_csi_mbus_code_idx(mbus_fmt_code);
> +
> +	if (ret < 0) {
> +		v4l2_dbg(1, debug, sd, "%s: unsupported format code 0x%x",
> +			 __func__, mbus_fmt_code);
> +		return ret;
> +	}
> +
> +	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> +		v4l2_dbg(1, debug, sd, "%s: try format code = 0x%x",
> +			 __func__, format->format.code);
> +		return 0;

[Severity: Medium]
Does returning early here fail to save the negotiated format to the
v4l2_subdev_state? This would prevent userspace from configuring the
pipeline correctly since the TRY format is never recorded.

> +	}
> +
> +	it6625->csi_format = it6625_formats[ret].csi_format;
> +	it6625->mbus_fmt_code = format->format.code;

[Severity: Medium]
Are these modifications to the format state subject to data races? 

Since the driver does not configure sd->devnode->lock to serialize ioctls,
concurrent calls to VIDIOC_SUBDEV_S_FMT might corrupt this state if the
it6625_lock is not acquired.

> +	it6625_enable_stream(it6625, false);
[ ... ]
> +static int it6625_s_edid(struct v4l2_subdev *sd,
> +			 struct v4l2_subdev_edid *edid)
> +{
> +	struct it6625 *it6625 = sd_to_6625(sd);
> +	int err;
> +	u16 pa;
> +
> +	if (edid->pad != 0) {
> +		v4l2_err(sd, "invalid pad %d", edid->pad);
> +		return -EINVAL;
> +	}
> +
> +	memset(edid->reserved, 0, sizeof(edid->reserved));
> +
> +	it6625_disable_hpd(it6625);
> +
> +	if (edid->blocks != 0) {
> +		err = it6625_write_edid(it6625, edid->edid,
> +					edid->start_block, edid->blocks);
> +		if (err) {
> +			v4l2_err(sd, "write edid failed");
> +			return err;

[Severity: High]
Because it6625_write_edid returns the positive number of blocks on success,
will this condition incorrectly treat a successful write as a failure and
skip the remaining initialization?

> +		}
> +	}
> +
> +	pa = cec_get_edid_phys_addr(edid->edid, edid->blocks * 128, NULL);
> +	if (pa == CEC_PHYS_ADDR_INVALID) {
> +		v4l2_warn(sd, "invalid CEC physical address in EDID");
> +		cec_phys_addr_invalidate(it6625->cec_adap);
> +	} else {
> +		v4l2_phys_addr_validate(pa, NULL, NULL);
> +		cec_s_phys_addr(it6625->cec_adap, pa, false);
> +	}
> +
> +	if (hdmi_5v_power_present(it6625)) {
> +		it6625_enable_hpd(it6625);

[Severity: High]
If this is called concurrently with it6625_remove, could it6625_enable_hpd
reschedule the hpd_delayed_work after it was already canceled by remove?
This would result in a use-after-free when the devres-managed structure is
destroyed.

> +		it6625_s_ctrl_detect_hdmi_5v(sd);
> +	} else {
> +		it6625_enable_auto_hpd(it6625);
> +	}
[ ... ]
> +static int it6625_probe(struct i2c_client *client)
> +{
> +	struct it6625 *it6625;
> +	struct v4l2_subdev *sd;
> +	int err;
> +
> +	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> +		return -EIO;
> +
> +	it6625 = devm_kzalloc(&client->dev, sizeof(struct it6625), GFP_KERNEL);

[Severity: High]
Is it safe to tie the lifetime of the it6625 structure to the device bind
lifecycle using devm_kzalloc, given that it exposes a V4L2 subdevice node?
Userspace processes holding an open file descriptor could trigger ioctls that
access this freed memory after the device unbinds.

> +	if (!it6625)
> +		return -ENOMEM;
[ ... ]
> +static void it6625_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct it6625 *it6625 = sd_to_6625(sd);
> +
> +	v4l2_async_unregister_subdev(sd);
> +	v4l2_device_unregister_subdev(sd);
> +
> +	if (client->irq)
> +		disable_irq(client->irq);
> +	else
> +		timer_shutdown_sync(&it6625->timer);
> +
> +	cancel_work_sync(&it6625->polling_work);

[Severity: High]
Does unregistering the subdevice before disabling IRQs, timers, and
workqueues open a window for a use-after-free? 

An interrupt or timer firing in this window could schedule the polling work,
which would then attempt to access the unregistered and potentially freed
subdevice structures.

> +	cancel_delayed_work_sync(&it6625->hpd_delayed_work);
> +	debugfs_remove_recursive(it6625->debugfs_dir);
> +	cec_unregister_adapter(it6625->cec_adap);
> +	mutex_destroy(&it6625->it6625_lock);
> +	media_entity_cleanup(&sd->entity);
> +	v4l2_ctrl_handler_free(&it6625->hdl);
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260721-upstream-it6625-it6626-v2-0-7c4f3564ca38@ite.com.tw?part=2