[PATCH v5 0/2] media: i2c: Add ov2735 camera sensor driver

[PATCH v5 0/2] media: i2c: Add ov2735 camera sensor driver

[Hardevsinh Palaniya]

The Omnivision OV2735 is a 1/2.7-Inch CMOS image sensor with an
active array size of 1920 x 1080.

The following features are supported:
- Manual exposure an gain control support.
- vblank/hblank control support.
- Test pattern support control.
- Supported resolution: 1920 x 1080 @ 30fps (SGRBG10).

The driver is tested on mainline branch v6.14-rc6 on IMX8MP Debix Model a.

v4 -> v5

In Patch 1/2:
- Add Krzysztof's Review tag.

In Patch 2/2:
- Remove redundant if (ret && err) check in ov2735_page_access()
- Address coding style issues (indentation, format specifier, combined declaration)
- Replace hardcoded values with USEC_PER_MSEC where appropriate
- removing unused "ov2735->client = client"
 
v3 -> v4

In Patch 1/2:
- Removed the clock-names property from the device tree binding.
- Added link-frequencies property to the port node.
- Cleaned up the example by removing unnecessary entries.

In Patch 2/2:
- Removed the cci_ prefix from read/write functions and custom page macros.
- Corrected error handling in the ov2735_page_access() function.
- Calculated PLL parameters dynamically based on the specified link frequency.
- Set resolution registers from format and crop instead of hardcoding.
- Fixed a memory leak in ov2735_parse_endpoint().
- Switched to devm_pm_runtime_*() functions for runtime PM handling.
- Added documentation for the use of msleep() in the power_on() function.
- Corrected GPIO polarity handling in the power_off() function.

v2 -> v3

In Patch 1/2:
- Renamed pwdn pin to enable pin.
- Changed supply names to lowercase and added them to required properties.

In Patch 2/2:
- Stored page number in CCI private bits.
- Added helper functions to handle page switching in cci_read() and cci_write().
- Removed ov2735_mbus_codes.
- Corrected control count to 9.

v1 -> v2

- Added necessary header files.
- Corrected indentation.
- Used the ret parameter in cci_write and cci_read functions.

Hardevsinh Palaniya (1):
  media: i2c: add ov2735 image sensor driver

Himanshu Bhavani (1):
  dt-bindings: media: i2c: Add ov2735 sensor

 .../bindings/media/i2c/ovti,ov2735.yaml       |  109 ++
 MAINTAINERS                                   |    9 +
 drivers/media/i2c/Kconfig                     |   10 +
 drivers/media/i2c/Makefile                    |    1 +
 drivers/media/i2c/ov2735.c                    | 1060 +++++++++++++++++
 5 files changed, 1189 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ovti,ov2735.yaml
 create mode 100644 drivers/media/i2c/ov2735.c

-- 
2.34.1

[PATCH v5 1/2] dt-bindings: media: i2c: Add ov2735 sensor

[Hardevsinh Palaniya]

From: Himanshu Bhavani <himanshu.bhavani@siliconsignals.io>

Add bindings for Omnivision OV2735 sensor.

Signed-off-by: Himanshu Bhavani <himanshu.bhavani@siliconsignals.io>
Signed-off-by: Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../bindings/media/i2c/ovti,ov2735.yaml       | 109 ++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ovti,ov2735.yaml

diff --git a/Documentation/devicetree/bindings/media/i2c/ovti,ov2735.yaml b/Documentation/devicetree/bindings/media/i2c/ovti,ov2735.yaml
new file mode 100644
index 000000000000..9236829cc00d
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/ovti,ov2735.yaml
@@ -0,0 +1,109 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/ovti,ov2735.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: OmniVision OV2735 Image Sensor
+
+maintainers:
+  - Himanshu Bhavani <himanshu.bhavani@siliconsignals.io>
+
+description:
+  The OmniVision OV2735 is a 2MP (1920x1080) color CMOS image sensor controlled
+  through an I2C-compatible SCCB bus. it outputs RAW10 format and uses a 1/2.7"
+  optical format.
+
+properties:
+  compatible:
+    const: ovti,ov2735
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: XVCLK clock
+
+  avdd-supply:
+    description: Analog Domain Power Supply
+
+  dovdd-supply:
+    description: I/O Domain Power Supply
+
+  dvdd-supply:
+    description: Digital Domain Power Supply
+
+  reset-gpios:
+    maxItems: 1
+    description: Reset Pin GPIO Control (active low)
+
+  enable-gpios:
+    maxItems: 1
+    description:
+      Active-low enable pin. Labeled as 'PWDN' in the datasheet, but acts as
+      an enable signal. During power rail ramp-up, the device remains powered
+      down. Once power rails are stable, pulling this pin low powers on the
+      device.
+
+  port:
+    description: MIPI CSI-2 transmitter port
+    $ref: /schemas/graph.yaml#/$defs/port-base
+    additionalProperties: false
+
+    properties:
+      endpoint:
+        $ref: /schemas/media/video-interfaces.yaml#
+        unevaluatedProperties: false
+
+        properties:
+          data-lanes:
+            items:
+              - const: 1
+              - const: 2
+          link-frequencies: true
+
+        required:
+          - data-lanes
+          - link-frequencies
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - avdd-supply
+  - dovdd-supply
+  - dvdd-supply
+  - port
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        camera-sensor@3c {
+            compatible = "ovti,ov2735";
+            reg = <0x3c>;
+            clocks = <&ov2735_clk>;
+
+            avdd-supply = <&ov2735_avdd>;
+            dovdd-supply = <&ov2735_dovdd>;
+            dvdd-supply = <&ov2735_dvdd>;
+
+            reset-gpios = <&gpio1 6 GPIO_ACTIVE_LOW>;
+            enable-gpios = <&gpio2 11 GPIO_ACTIVE_LOW>;
+
+            port {
+                cam_out: endpoint {
+                    remote-endpoint = <&mipi_in_cam>;
+                    data-lanes = <1 2>;
+                    link-frequencies = /bits/ 64 <420000000>;
+                };
+            };
+        };
+    };
-- 
2.34.1

[PATCH v5 2/2] media: i2c: add ov2735 image sensor driver

[Hardevsinh Palaniya]

Add a v4l2 subdevice driver for the Omnivision OV2735 sensor.

The Omnivision OV2735 is a 1/2.7-Inch CMOS image sensor with an
active array size of 1920 x 1080.

The following features are supported:
- Manual exposure an gain control support
- vblank/hblank control support
- Test pattern support control
- Supported resolution: 1920 x 1080 @ 30fps (SGRBG10)

Co-developed-by: Himanshu Bhavani <himanshu.bhavani@siliconsignals.io>
Signed-off-by: Himanshu Bhavani <himanshu.bhavani@siliconsignals.io>
Signed-off-by: Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
---
 MAINTAINERS                |    9 +
 drivers/media/i2c/Kconfig  |   10 +
 drivers/media/i2c/Makefile |    1 +
 drivers/media/i2c/ov2735.c | 1060 ++++++++++++++++++++++++++++++++++++
 4 files changed, 1080 insertions(+)
 create mode 100644 drivers/media/i2c/ov2735.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 92e9d8c7708f..058bbfd9523b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18471,6 +18471,15 @@ T:	git git://linuxtv.org/media.git
 F:	Documentation/devicetree/bindings/media/i2c/ovti,ov2685.yaml
 F:	drivers/media/i2c/ov2685.c
 
+OMNIVISION OV2735 SENSOR DRIVER
+M:	Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
+M:	Himanshu Bhavani <himanshu.bhavani@siliconsignals.io>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+T:	git git://linuxtv.org/media.git
+F:	Documentation/devicetree/bindings/media/i2c/ovti,ov2735.yaml
+F:	drivers/media/i2c/ov2735.c
+
 OMNIVISION OV2740 SENSOR DRIVER
 M:	Tianshu Qiu <tian.shu.qiu@intel.com>
 R:	Sakari Ailus <sakari.ailus@linux.intel.com>
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 4b4c199da6ea..9646eab1b177 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -446,6 +446,16 @@ config VIDEO_OV2685
 	  To compile this driver as a module, choose M here: the
 	  module will be called ov2685.
 
+config VIDEO_OV2735
+	tristate "OmniVision OV2735 sensor support"
+	select V4L2_CCI_I2C
+	help
+	  This is a Video4Linux2 sensor driver for the Sony
+	  OV2735 camera.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ov2735.
+
 config VIDEO_OV2740
 	tristate "OmniVision OV2740 sensor support"
 	depends on ACPI || COMPILE_TEST
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 5873d29433ee..1adb27743fa1 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_VIDEO_OV2640) += ov2640.o
 obj-$(CONFIG_VIDEO_OV2659) += ov2659.o
 obj-$(CONFIG_VIDEO_OV2680) += ov2680.o
 obj-$(CONFIG_VIDEO_OV2685) += ov2685.o
+obj-$(CONFIG_VIDEO_OV2735) += ov2735.o
 obj-$(CONFIG_VIDEO_OV2740) += ov2740.o
 obj-$(CONFIG_VIDEO_OV4689) += ov4689.o
 obj-$(CONFIG_VIDEO_OV5640) += ov5640.o
diff --git a/drivers/media/i2c/ov2735.c b/drivers/media/i2c/ov2735.c
new file mode 100644
index 000000000000..4431adec0ecb
--- /dev/null
+++ b/drivers/media/i2c/ov2735.c
@@ -0,0 +1,1060 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * V4L2 Support for the OV2735
+ *
+ * Copyright (C) 2025 Silicon Signals Pvt. Ltd.
+ *
+ * Based on Rockchip ov2735 Camera Driver
+ * Copyright (C) 2017 Fuzhou Rockchip Electronics Co., Ltd.
+ *
+ * Inspired from ov8858, imx219, imx283 camera drivers
+ */
+
+#include <linux/array_size.h>
+#include <linux/clk.h>
+#include <linux/container_of.h>
+#include <linux/delay.h>
+#include <linux/device/devres.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/units.h>
+#include <linux/types.h>
+#include <vdso/time64.h>
+
+#include <media/v4l2-cci.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mediabus.h>
+
+#define OV2735_XCLK_FREQ			(24 * HZ_PER_MHZ)
+
+/* Add page number in CCI private bits [31:28] of the register address */
+#define OV2735_PAGE_REG8(p, x)			(((p) << CCI_REG_PRIVATE_SHIFT) | CCI_REG8(x))
+#define OV2735_PAGE_REG16(p, x)			(((p) << CCI_REG_PRIVATE_SHIFT) | CCI_REG16(x))
+
+#define OV2735_REG_PAGE_SELECT			CCI_REG8(0xfd)
+
+/* Page 0 */
+#define OV2735_REG_CHIPID			OV2735_PAGE_REG16(0x00, 0x02)
+#define OV2735_CHIPID				0x2735
+
+#define OV2735_REG_SOFT_REST			OV2735_PAGE_REG8(0x00, 0x20)
+
+/* Clock Settings */
+#define OV2735_REG_PLL_CTRL			OV2735_PAGE_REG8(0x00, 0x2f)
+#define OV2735_REG_PLL_ENABLE			0x7f
+#define OV2735_REG_PLL_OUTDIV			OV2735_PAGE_REG8(0x00, 0x34)
+#define OV2735_REG_CLK_MODE			OV2735_PAGE_REG8(0x00, 0x30)
+#define OV2735_REG_CLOCK_REG1			OV2735_PAGE_REG8(0x00, 0x33)
+#define OV2735_REG_CLOCK_REG2			OV2735_PAGE_REG8(0x00, 0x35)
+
+/* Page 1 */
+#define OV2735_REG_STREAM_CTRL			OV2735_PAGE_REG8(0x01, 0xa0)
+#define OV2735_STREAM_ON			0x01
+#define OV2735_STREAM_OFF			0x00
+
+#define OV2735_REG_UPDOWN_MIRROR		OV2735_PAGE_REG8(0x01, 0x3f)
+#define OV2735_REG_BINNING_DAC_CODE_MODE	OV2735_PAGE_REG8(0x01, 0x30)
+#define OV2735_REG_FRAME_LENGTH			OV2735_PAGE_REG16(0x01, 0x0e)
+#define OV2735_VTS_MAX				0x0fff
+#define OV2735_REG_FRAME_EXP_SEPERATE_EN	OV2735_PAGE_REG8(0x01, 0x0d)
+#define OV2735_FRAME_EXP_SEPERATE_EN		0x10
+#define OV2735_REG_FRAME_SYNC			OV2735_PAGE_REG8(0x01, 0x01)
+
+#define OV2735_REG_HBLANK			OV2735_PAGE_REG16(0x01, 0x09)
+
+#define OV2735_REG_HS_MIPI			OV2735_PAGE_REG8(0x01, 0xb1)
+#define OV2735_REG_MIPI_CTRL1			OV2735_PAGE_REG8(0x01, 0x92)
+#define OV2735_REG_MIPI_CTRL2			OV2735_PAGE_REG8(0x01, 0x94)
+#define OV2735_REG_MIPI_CTRL3			OV2735_PAGE_REG8(0x01, 0xa1)
+#define OV2735_REG_MIPI_CTRL4			OV2735_PAGE_REG8(0x01, 0xb2)
+#define OV2735_REG_MIPI_CTRL5			OV2735_PAGE_REG8(0x01, 0xb3)
+#define OV2735_REG_MIPI_CTRL6			OV2735_PAGE_REG8(0x01, 0xb4)
+#define OV2735_REG_MIPI_CTRL7			OV2735_PAGE_REG8(0x01, 0xb5)
+#define OV2735_REG_PREPARE			OV2735_PAGE_REG8(0x01, 0x95)
+#define OV2735_REG_R_HS_ZERO			OV2735_PAGE_REG8(0x01, 0x96)
+#define OV2735_REG_TRAIL			OV2735_PAGE_REG8(0x01, 0x98)
+#define OV2735_REG_R_CLK_ZERO			OV2735_PAGE_REG8(0x01, 0x9c)
+#define OV2735_REG_MIPI_COLOMN_NUMBER		OV2735_PAGE_REG16(0x01, 0x8e)
+#define OV2735_REG_MIPI_LINE_NUMBER		OV2735_PAGE_REG16(0x01, 0x90)
+
+#define OV2735_REG_ANALOG_CTRL3			OV2735_PAGE_REG8(0x01, 0x25)
+#define OV2735_REG_VNCP				OV2735_PAGE_REG8(0x01, 0x20)
+
+/* BLC registers */
+#define OV2735_REG_BLC_GAIN_BLUE		OV2735_PAGE_REG8(0x01, 0x86)
+#define OV2735_REG_BLC_GAIN_RED			OV2735_PAGE_REG8(0x01, 0x87)
+#define OV2735_REG_BLC_GAIN_GR			OV2735_PAGE_REG8(0x01, 0x88)
+#define OV2735_REG_BLC_GAIN_GB			OV2735_PAGE_REG8(0x01, 0x89)
+#define OV2735_REG_GB_SUBOFFSET			OV2735_PAGE_REG8(0x01, 0xf0)
+#define OV2735_REG_BLUE_SUBOFFSET		OV2735_PAGE_REG8(0x01, 0xf1)
+#define OV2735_REG_RED_SUBOFFSET		OV2735_PAGE_REG8(0x01, 0xf2)
+#define OV2735_REG_GR_SUBOFFSET			OV2735_PAGE_REG8(0x01, 0xf3)
+#define OV2735_REG_BLC_BPC_TH_P			OV2735_PAGE_REG8(0x01, 0xfc)
+#define OV2735_REG_BLC_BPC_TH_N			OV2735_PAGE_REG8(0x01, 0xfe)
+
+#define OV2735_REG_TEST_PATTERN			OV2735_PAGE_REG8(0x01, 0xb2)
+#define OV2735_TEST_PATTERN_ENABLE		0x01
+#define OV2735_TEST_PATTERN_DISABLE		0xfe
+
+#define OV2735_REG_LONG_EXPOSURE		OV2735_PAGE_REG16(0x01, 0x03)
+#define	OV2735_EXPOSURE_MIN			4
+#define	OV2735_EXPOSURE_STEP			1
+
+#define OV2735_REG_ANALOG_GAIN                  OV2735_PAGE_REG8(0x01, 0x24)
+#define	OV2735_ANALOG_GAIN_MIN			0x10
+#define	OV2735_ANALOG_GAIN_MAX			0xff
+#define	OV2735_ANALOG_GAIN_STEP			1
+#define	OV2735_ANALOG_GAIN_DEFAULT		0x10
+
+/* Page 2 */
+#define OV2735_REG_V_START			OV2735_PAGE_REG16(0x02, 0xa0)
+#define OV2735_REG_V_SIZE			OV2735_PAGE_REG16(0x02, 0xa2)
+#define OV2735_REG_H_START			OV2735_PAGE_REG16(0x02, 0xa4)
+#define OV2735_REG_H_SIZE			OV2735_PAGE_REG16(0x02, 0xa6)
+
+#define OV2735_LINK_FREQ_420MHZ			(420 * HZ_PER_MHZ)
+#define OV2735_PIXEL_RATE			(168 * HZ_PER_MHZ)
+
+/* OV2735 native and active pixel array size. */
+static const struct v4l2_rect ov2735_native_area = {
+	.top = 0,
+	.left = 0,
+	.width = 1936,
+	.height = 1096,
+};
+
+static const struct v4l2_rect ov2735_active_area = {
+	.top = 8,
+	.left = 8,
+	.width = 1920,
+	.height = 1080,
+};
+
+static const char * const ov2735_supply_name[] = {
+	"avdd",		/* Analog power */
+	"dovdd",	/* Digital I/O power */
+	"dvdd",		/* Digital core power */
+};
+
+/* PLL_OUT = [PLL_IN * (pll_nc +3)] / [(pll_mc + 1) * (pll_outdiv + 1)] */
+struct ov2735_pll_parameters {
+	u8 pll_nc;
+	u8 pll_mc;
+	u8 pll_outdiv;
+};
+
+struct ov2735 {
+	struct device *dev;
+	struct regmap *cci;
+	struct v4l2_subdev sd;
+	struct media_pad pad;
+	struct i2c_client *client;
+	struct clk *xclk;
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *enable_gpio;
+	struct regulator_bulk_data supplies[ARRAY_SIZE(ov2735_supply_name)];
+
+	/* V4L2 Controls */
+	struct v4l2_ctrl_handler handler;
+	struct v4l2_ctrl *link_freq;
+	struct v4l2_ctrl *pixel_rate;
+	struct v4l2_ctrl *hblank;
+	struct v4l2_ctrl *vblank;
+	struct v4l2_ctrl *gain;
+	struct v4l2_ctrl *exposure;
+	struct v4l2_ctrl *test_pattern;
+
+	u32 link_freq_index;
+
+	u8 current_page;
+	struct mutex page_lock;
+};
+
+struct ov2735_mode {
+	u32 width;
+	u32 height;
+	u32 hts_def;
+	u32 vts_def;
+	u32 exp_def;
+	struct v4l2_rect crop;
+};
+
+static struct cci_reg_sequence ov2735_common_regs[] = {
+	{ OV2735_REG_CLK_MODE,			0x15 },
+	{ OV2735_REG_CLOCK_REG1,		0x01 },
+	{ OV2735_REG_CLOCK_REG2,		0x20 },
+	{ OV2735_REG_BINNING_DAC_CODE_MODE,	0x00 },
+	{ OV2735_PAGE_REG8(0x01, 0xfb),		0x73 },
+	{ OV2735_REG_FRAME_SYNC,		0x01 },
+
+	/* Timing ctrl */
+	{ OV2735_PAGE_REG8(0x01, 0x1a),		0x6b },
+	{ OV2735_PAGE_REG8(0x01, 0x1c),		0xea },
+	{ OV2735_PAGE_REG8(0x01, 0x16),		0x0c },
+	{ OV2735_PAGE_REG8(0x01, 0x21),		0x00 },
+	{ OV2735_PAGE_REG8(0x01, 0x11),		0x63 },
+	{ OV2735_PAGE_REG8(0x01, 0x19),		0xc3 },
+
+	/* Analog ctrl */
+	{ OV2735_PAGE_REG8(0x01, 0x26),		0x5a },
+	{ OV2735_PAGE_REG8(0x01, 0x29),		0x01 },
+	{ OV2735_PAGE_REG8(0x01, 0x33),		0x6f },
+	{ OV2735_PAGE_REG8(0x01, 0x2a),		0xd2 },
+	{ OV2735_PAGE_REG8(0x01, 0x2c),		0x40 },
+	{ OV2735_PAGE_REG8(0x01, 0xd0),		0x02 },
+	{ OV2735_PAGE_REG8(0x01, 0xd1),		0x01 },
+	{ OV2735_PAGE_REG8(0x01, 0xd2),		0x20 },
+	{ OV2735_PAGE_REG8(0x01, 0xd3),		0x04 },
+	{ OV2735_PAGE_REG8(0x01, 0xd4),		0x2a },
+	{ OV2735_PAGE_REG8(0x01, 0x50),		0x00 },
+	{ OV2735_PAGE_REG8(0x01, 0x51),		0x2c },
+	{ OV2735_PAGE_REG8(0x01, 0x52),		0x29 },
+	{ OV2735_PAGE_REG8(0x01, 0x53),		0x00 },
+	{ OV2735_PAGE_REG8(0x01, 0x55),		0x44 },
+	{ OV2735_PAGE_REG8(0x01, 0x58),		0x29 },
+	{ OV2735_PAGE_REG8(0x01, 0x5a),		0x00 },
+	{ OV2735_PAGE_REG8(0x01, 0x5b),		0x00 },
+	{ OV2735_PAGE_REG8(0x01, 0x5d),		0x00 },
+	{ OV2735_PAGE_REG8(0x01, 0x64),		0x2f },
+	{ OV2735_PAGE_REG8(0x01, 0x66),		0x62 },
+	{ OV2735_PAGE_REG8(0x01, 0x68),		0x5b },
+	{ OV2735_PAGE_REG8(0x01, 0x75),		0x46 },
+	{ OV2735_PAGE_REG8(0x01, 0x76),		0x36 },
+	{ OV2735_PAGE_REG8(0x01, 0x77),		0x4f },
+	{ OV2735_PAGE_REG8(0x01, 0x78),		0xef },
+	{ OV2735_PAGE_REG8(0x01, 0x72),		0xcf },
+	{ OV2735_PAGE_REG8(0x01, 0x73),		0x36 },
+	{ OV2735_PAGE_REG8(0x01, 0x7d),		0x0d },
+	{ OV2735_PAGE_REG8(0x01, 0x7e),		0x0d },
+	{ OV2735_PAGE_REG8(0x01, 0x8a),		0x77 },
+	{ OV2735_PAGE_REG8(0x01, 0x8b),		0x77 },
+
+	{ OV2735_REG_HS_MIPI,			0x83 },
+	{ OV2735_REG_MIPI_CTRL5,		0x0b },
+	{ OV2735_REG_MIPI_CTRL6,		0x14 },
+	{ OV2735_PAGE_REG8(0x01, 0x9d),		0x40 },
+	{ OV2735_REG_MIPI_CTRL3,		0x05 },
+	{ OV2735_REG_MIPI_CTRL2,		0x44 },
+	{ OV2735_REG_PREPARE,			0x33 },
+	{ OV2735_REG_R_HS_ZERO,			0x1f },
+	{ OV2735_REG_TRAIL,			0x45 },
+	{ OV2735_REG_R_CLK_ZERO,		0x10 },
+	{ OV2735_REG_MIPI_CTRL7,		0x70 },
+	{ OV2735_REG_ANALOG_CTRL3,		0xe0 },
+	{ OV2735_REG_VNCP,			0x7b },
+
+	/* BLC */
+	{ OV2735_REG_BLC_GAIN_BLUE,		0x77 },
+	{ OV2735_REG_BLC_GAIN_GB,		0x77 },
+	{ OV2735_REG_BLC_GAIN_RED,		0x74 },
+	{ OV2735_REG_BLC_GAIN_GR,		0x74 },
+	{ OV2735_REG_BLC_BPC_TH_P,		0xe0 },
+	{ OV2735_REG_BLC_BPC_TH_N,		0xe0 },
+	{ OV2735_REG_GB_SUBOFFSET,		0x40 },
+	{ OV2735_REG_BLUE_SUBOFFSET,		0x40 },
+	{ OV2735_REG_RED_SUBOFFSET,		0x40 },
+	{ OV2735_REG_GR_SUBOFFSET,		0x40 },
+};
+
+static const struct ov2735_mode supported_modes[] = {
+	{
+		.width = 1920,
+		.height = 1080,
+		.exp_def = 399,
+		.hts_def = 2200,
+		.vts_def = 2545,
+		.crop = {
+			.top = 8,
+			.left = 8,
+			.width = 1920,
+			.height = 1080,
+		},
+	},
+};
+
+static const s64 link_freq_menu_items[] = {
+	OV2735_LINK_FREQ_420MHZ,
+};
+
+struct ov2735_pll_parameters pll_configs[] = {
+	/* For 420MHz pll_configs. */
+	{
+		.pll_nc = 4,
+		.pll_mc = 0,
+		.pll_outdiv = 1,
+	},
+};
+
+static const char * const ov2735_test_pattern_menu[] = {
+	"Disabled",
+	"Vertical Color",
+};
+
+static int ov2735_page_access(struct ov2735 *ov2735,
+			      u32 reg, void *val, int *err, bool is_read)
+{
+	u8 page = (reg >> CCI_REG_PRIVATE_SHIFT) & 0xff;
+	u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
+	int ret = 0;
+
+	if (err && *err)
+		return *err;
+
+	mutex_lock(&ov2735->page_lock);
+
+	/* Perform page access before read/write */
+	if (ov2735->current_page != page) {
+		ret = cci_write(ov2735->cci, OV2735_REG_PAGE_SELECT, page, err);
+		if (ret)
+			goto err_mutex_unlock;
+		ov2735->current_page = page;
+	}
+
+	if (is_read)
+		ret = cci_read(ov2735->cci, addr, (u64 *)val, err);
+	else
+		ret = cci_write(ov2735->cci, addr, *(u64 *)val, err);
+
+err_mutex_unlock:
+	mutex_unlock(&ov2735->page_lock);
+	return ret;
+}
+
+static int ov2735_read(struct ov2735 *ov2735, u32 reg, u64 *val, int *err)
+{
+	return ov2735_page_access(ov2735, reg, val, err, true);
+}
+
+static int ov2735_write(struct ov2735 *ov2735, u32 reg, u64 val, int *err)
+{
+	return ov2735_page_access(ov2735, reg, (void *)&val, err, false);
+}
+
+static int ov2735_multi_reg_write(struct ov2735 *ov2735,
+				  const struct cci_reg_sequence *regs,
+				  unsigned int num_regs, int *err)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < num_regs; i++) {
+		ret = ov2735_write(ov2735, regs[i].reg, regs[i].val, err);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static inline struct ov2735 *to_ov2735(struct v4l2_subdev *_sd)
+{
+	return container_of(_sd, struct ov2735, sd);
+}
+
+static int ov2735_enable_test_pattern(struct ov2735 *ov2735, u32 pattern)
+{
+	int ret;
+	u64 val;
+
+	ret = ov2735_read(ov2735, OV2735_REG_TEST_PATTERN, &val, NULL);
+	if (ret)
+		return ret;
+
+	switch (pattern) {
+	case 0:
+		val &= ~OV2735_TEST_PATTERN_ENABLE;
+		break;
+	case 1:
+		val |= OV2735_TEST_PATTERN_ENABLE;
+		break;
+	}
+
+	return ov2735_write(ov2735, OV2735_REG_TEST_PATTERN, val, NULL);
+}
+
+static int ov2735_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct ov2735 *ov2735 = container_of(ctrl->handler, struct ov2735,
+					     handler);
+	struct v4l2_mbus_framefmt *fmt;
+	struct v4l2_subdev_state *state;
+	u64 vts;
+	int ret = 0;
+
+	state = v4l2_subdev_get_locked_active_state(&ov2735->sd);
+	fmt = v4l2_subdev_state_get_format(state, 0);
+
+	if (ctrl->id == V4L2_CID_VBLANK) {
+		/* Honour the VBLANK limits when setting exposure. */
+		s64 max = fmt->height + ctrl->val - 4;
+
+		ret = __v4l2_ctrl_modify_range(ov2735->exposure,
+					       ov2735->exposure->minimum, max,
+					       ov2735->exposure->step,
+					       ov2735->exposure->default_value);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Applying V4L2 control value only happens
+	 * when power is up for streaming.
+	 */
+	if (pm_runtime_get_if_in_use(ov2735->dev) == 0)
+		return 0;
+
+	switch (ctrl->id) {
+	case V4L2_CID_EXPOSURE:
+		ov2735_write(ov2735, OV2735_REG_LONG_EXPOSURE, ctrl->val, &ret);
+		break;
+	case V4L2_CID_ANALOGUE_GAIN:
+		ov2735_write(ov2735, OV2735_REG_ANALOG_GAIN, ctrl->val, &ret);
+		break;
+	case V4L2_CID_HBLANK:
+		ov2735_write(ov2735, OV2735_REG_HBLANK, ctrl->val, &ret);
+		break;
+	case V4L2_CID_VBLANK:
+		vts = ctrl->val + fmt->height;
+		ov2735_write(ov2735, OV2735_REG_FRAME_EXP_SEPERATE_EN,
+			     OV2735_FRAME_EXP_SEPERATE_EN, &ret);
+		ov2735_write(ov2735, OV2735_REG_FRAME_LENGTH, vts, &ret);
+		break;
+	case V4L2_CID_TEST_PATTERN:
+		ret = ov2735_enable_test_pattern(ov2735, ctrl->val);
+		break;
+	default:
+		dev_err(ov2735->dev, "ctrl(id:0x%x, val:0x%x) is not handled\n",
+			ctrl->id, ctrl->val);
+		break;
+	}
+	ov2735_write(ov2735, OV2735_REG_FRAME_SYNC, 0x01, &ret);
+
+	pm_runtime_put(ov2735->dev);
+
+	return ret;
+}
+
+static const struct v4l2_ctrl_ops ov2735_ctrl_ops = {
+	.s_ctrl = ov2735_set_ctrl,
+};
+
+static int ov2735_init_controls(struct ov2735 *ov2735)
+{
+	struct v4l2_ctrl_handler *ctrl_hdlr;
+	struct v4l2_fwnode_device_properties props;
+	const struct ov2735_mode *mode = &supported_modes[0];
+	u64 hblank_def, vblank_def, exp_max;
+	int ret;
+
+	ctrl_hdlr = &ov2735->handler;
+	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 9);
+	if (ret)
+		return ret;
+
+	ov2735->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
+					       V4L2_CID_PIXEL_RATE, 0, OV2735_PIXEL_RATE,
+					       1, OV2735_PIXEL_RATE);
+
+	ov2735->link_freq = v4l2_ctrl_new_int_menu(ctrl_hdlr, &ov2735_ctrl_ops,
+						   V4L2_CID_LINK_FREQ,
+						   ov2735->link_freq_index,
+						   0, link_freq_menu_items);
+	if (ov2735->link_freq)
+		ov2735->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	hblank_def = mode->hts_def - mode->width;
+	ov2735->hblank = v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops, V4L2_CID_HBLANK,
+					   hblank_def, hblank_def, 1, hblank_def);
+
+	vblank_def = mode->vts_def - mode->height;
+	ov2735->vblank = v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
+					   V4L2_CID_VBLANK, vblank_def,
+					   OV2735_VTS_MAX - mode->height,
+					   1, vblank_def);
+
+	exp_max = mode->vts_def - 4;
+	ov2735->exposure = v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
+					     V4L2_CID_EXPOSURE, OV2735_EXPOSURE_MIN,
+					     exp_max, OV2735_EXPOSURE_STEP, mode->exp_def);
+
+	ov2735->gain = v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
+					 V4L2_CID_ANALOGUE_GAIN, OV2735_ANALOG_GAIN_MIN,
+					 OV2735_ANALOG_GAIN_MAX, OV2735_ANALOG_GAIN_STEP,
+					 OV2735_ANALOG_GAIN_DEFAULT);
+
+	ov2735->test_pattern = v4l2_ctrl_new_std_menu_items(ctrl_hdlr,
+						&ov2735_ctrl_ops, V4L2_CID_TEST_PATTERN,
+						ARRAY_SIZE(ov2735_test_pattern_menu) - 1,
+						0, 0, ov2735_test_pattern_menu);
+	if (ctrl_hdlr->error) {
+		ret = ctrl_hdlr->error;
+		dev_err(ov2735->dev, "control init failed (%d)\n", ret);
+		goto err_handler_free;
+	}
+
+	ret = v4l2_fwnode_device_parse(ov2735->dev, &props);
+	if (ret)
+		goto err_handler_free;
+
+	ret = v4l2_ctrl_new_fwnode_properties(ctrl_hdlr,
+					      &ov2735_ctrl_ops, &props);
+	if (ret)
+		goto err_handler_free;
+
+	ov2735->sd.ctrl_handler = ctrl_hdlr;
+
+	return 0;
+
+err_handler_free:
+	v4l2_ctrl_handler_free(ctrl_hdlr);
+
+	return ret;
+}
+
+static int ov2735_set_pll_ctrl(struct ov2735 *ov2735)
+{
+	struct ov2735_pll_parameters *pll_parameters;
+	u8 pll_ctrl;
+	u8 pll_outdiv;
+	int ret = 0;
+
+	pll_parameters = &pll_configs[ov2735->link_freq_index];
+
+	/* BIT[7]: pll_clk_sel, BIT[6:2]: pll_nc, BIT[1:0]: pll_mc */
+	pll_ctrl = ((pll_parameters->pll_nc << 2) |
+		    (pll_parameters->pll_mc << 0)) & OV2735_REG_PLL_ENABLE;
+
+	pll_outdiv = pll_parameters->pll_outdiv;
+
+	ov2735_write(ov2735, OV2735_REG_PLL_CTRL, pll_ctrl, &ret);
+	ov2735_write(ov2735, OV2735_REG_PLL_OUTDIV, pll_outdiv, &ret);
+
+	return ret;
+}
+
+static int ov2735_set_framefmt(struct ov2735 *ov2735,
+			       struct v4l2_subdev_state *state)
+{
+	const struct v4l2_mbus_framefmt *format;
+	const struct v4l2_rect *crop;
+	int ret = 0;
+
+	format = v4l2_subdev_state_get_format(state, 0);
+	crop = v4l2_subdev_state_get_crop(state, 0);
+
+	ov2735_write(ov2735, OV2735_REG_V_START, crop->top, &ret);
+	ov2735_write(ov2735, OV2735_REG_V_SIZE, format->height, &ret);
+	ov2735_write(ov2735, OV2735_REG_MIPI_LINE_NUMBER, format->height, &ret);
+	ov2735_write(ov2735, OV2735_REG_H_START, crop->left, &ret);
+	/* OV2735_REG_H_SIZE: Image half horizontal size */
+	ov2735_write(ov2735, OV2735_REG_H_SIZE, (format->width / 2), &ret);
+	ov2735_write(ov2735, OV2735_REG_MIPI_COLOMN_NUMBER, format->width, &ret);
+
+	return ret;
+}
+
+static int ov2735_enable_streams(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_state *state, u32 pad,
+				 u64 streams_mask)
+{
+	struct ov2735 *ov2735 = to_ov2735(sd);
+	const struct ov2735_mode *mode;
+	const struct v4l2_mbus_framefmt *fmt;
+	int ret;
+
+	fmt = v4l2_subdev_state_get_format(state, 0);
+	mode = v4l2_find_nearest_size(supported_modes,
+				      ARRAY_SIZE(supported_modes),
+				      width, height,
+				      fmt->width, fmt->height);
+
+	ret = pm_runtime_resume_and_get(ov2735->dev);
+	if (ret < 0)
+		return ret;
+
+	/* Apply pll settings. */
+	ret = ov2735_set_pll_ctrl(ov2735);
+	if (ret) {
+		dev_err(ov2735->dev, "failed to set frame format: %d\n", ret);
+		goto err_rpm_put;
+	}
+
+	ret = ov2735_multi_reg_write(ov2735, ov2735_common_regs,
+				     ARRAY_SIZE(ov2735_common_regs), NULL);
+	if (ret) {
+		dev_err(ov2735->dev, "%s failed to send mfg header\n", __func__);
+		goto err_rpm_put;
+	}
+
+	/* Apply format settings. */
+	ret = ov2735_set_framefmt(ov2735, state);
+	if (ret) {
+		dev_err(ov2735->dev, "failed to set frame format: %d\n", ret);
+		goto err_rpm_put;
+	}
+
+	/* Apply customized values from user */
+	ret = __v4l2_ctrl_handler_setup(ov2735->sd.ctrl_handler);
+	if (ret)
+		goto err_rpm_put;
+
+	/* set stream on register */
+	ret = ov2735_write(ov2735, OV2735_REG_STREAM_CTRL, OV2735_STREAM_ON, NULL);
+	if (ret)
+		goto err_rpm_put;
+
+	return 0;
+
+err_rpm_put:
+	pm_runtime_put(ov2735->dev);
+	return ret;
+}
+
+static int ov2735_disable_streams(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_state *state, u32 pad,
+				  u64 streams_mask)
+{
+	struct ov2735 *ov2735 = to_ov2735(sd);
+	int ret;
+
+	/* set stream off register */
+	ret = ov2735_write(ov2735, OV2735_REG_STREAM_CTRL, OV2735_STREAM_OFF, NULL);
+	if (ret)
+		dev_err(ov2735->dev, "%s failed to set stream\n", __func__);
+
+	pm_runtime_put(ov2735->dev);
+
+	return ret;
+}
+
+static int ov2735_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, 0);
+		return 0;
+	case V4L2_SEL_TGT_NATIVE_SIZE:
+		sel->r = ov2735_native_area;
+		return 0;
+	case V4L2_SEL_TGT_CROP_DEFAULT:
+	case V4L2_SEL_TGT_CROP_BOUNDS:
+		sel->r = ov2735_active_area;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ov2735_enum_mbus_code(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_state *sd_state,
+				 struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->index >= 0)
+		return -EINVAL;
+
+	code->code = MEDIA_BUS_FMT_SGRBG10_1X10;
+
+	return 0;
+}
+
+static int ov2735_enum_frame_size(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_state *sd_state,
+				  struct v4l2_subdev_frame_size_enum *fse)
+{
+	u32 code;
+
+	if (fse->index >= ARRAY_SIZE(supported_modes))
+		return -EINVAL;
+
+	code = MEDIA_BUS_FMT_SGRBG10_1X10;
+	if (fse->code != code)
+		return -EINVAL;
+
+	fse->min_width = supported_modes[fse->index].width;
+	fse->max_width = fse->min_width;
+	fse->min_height = supported_modes[fse->index].height;
+	fse->max_height = fse->min_height;
+
+	return 0;
+}
+
+static void ov2735_set_framing_limits(struct ov2735 *ov2735,
+				      const struct ov2735_mode *mode)
+{
+	u32 hblank, vblank_def;
+
+	hblank = mode->hts_def - mode->width;
+	__v4l2_ctrl_modify_range(ov2735->hblank, hblank, hblank, 1, hblank);
+
+	vblank_def = mode->vts_def - mode->height;
+	__v4l2_ctrl_modify_range(ov2735->vblank, vblank_def,
+				 OV2735_VTS_MAX - mode->height, 1, vblank_def);
+}
+
+static int ov2735_set_pad_format(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_state *sd_state,
+				 struct v4l2_subdev_format *fmt)
+{
+	struct v4l2_mbus_framefmt *format;
+	const struct ov2735_mode *mode;
+	struct v4l2_rect *crop;
+	struct ov2735 *ov2735 = to_ov2735(sd);
+
+	format = v4l2_subdev_state_get_format(sd_state, 0);
+
+	mode = v4l2_find_nearest_size(supported_modes,
+				      ARRAY_SIZE(supported_modes),
+				      width, height,
+				      fmt->format.width, fmt->format.height);
+
+	fmt->format.width = mode->width;
+	fmt->format.height = mode->height;
+	fmt->format.field = V4L2_FIELD_NONE;
+	fmt->format.colorspace = V4L2_COLORSPACE_RAW;
+	fmt->format.quantization = V4L2_QUANTIZATION_FULL_RANGE;
+	fmt->format.xfer_func = V4L2_XFER_FUNC_NONE;
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
+		ov2735_set_framing_limits(ov2735, mode);
+
+	*format = fmt->format;
+
+	/* Initialize crop rectangle */
+	crop = v4l2_subdev_state_get_crop(sd_state, 0);
+	*crop = mode->crop;
+
+	return 0;
+}
+
+static int ov2735_init_state(struct v4l2_subdev *sd,
+			     struct v4l2_subdev_state *state)
+{
+	struct v4l2_subdev_format fmt = {
+		.which = V4L2_SUBDEV_FORMAT_TRY,
+		.format = {
+			.code = MEDIA_BUS_FMT_SGRBG10_1X10,
+			.width = supported_modes[0].width,
+			.height = supported_modes[0].height,
+		},
+	};
+
+	ov2735_set_pad_format(sd, state, &fmt);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_video_ops ov2735_video_ops = {
+	.s_stream = v4l2_subdev_s_stream_helper,
+};
+
+static const struct v4l2_subdev_pad_ops ov2735_pad_ops = {
+	.enum_mbus_code = ov2735_enum_mbus_code,
+	.get_fmt = v4l2_subdev_get_fmt,
+	.set_fmt = ov2735_set_pad_format,
+	.get_selection = ov2735_get_selection,
+	.enum_frame_size = ov2735_enum_frame_size,
+	.enable_streams = ov2735_enable_streams,
+	.disable_streams = ov2735_disable_streams,
+};
+
+static const struct v4l2_subdev_ops ov2735_subdev_ops = {
+	.video = &ov2735_video_ops,
+	.pad = &ov2735_pad_ops,
+};
+
+static const struct v4l2_subdev_internal_ops ov2735_internal_ops = {
+	.init_state = ov2735_init_state,
+};
+
+static int ov2735_power_on(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct ov2735 *ov2735 = to_ov2735(sd);
+	int ret;
+
+	gpiod_set_value_cansleep(ov2735->enable_gpio, 0);
+	/*
+	 * Ensure device is inactive (PWDN high) before enabling power rails.
+	 * As per datasheet, the PWDN pin (named 'enable_gpio' here) should be
+	 * pulled low only after all power rails are stable.
+	 */
+	fsleep(3 * USEC_PER_MSEC);
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ov2735_supply_name),
+				    ov2735->supplies);
+	if (ret) {
+		dev_err(ov2735->dev, "failed to enable regulators\n");
+		return ret;
+	}
+
+	gpiod_set_value_cansleep(ov2735->enable_gpio, 1);
+	/* T4: delay from PWDN pulling low to RSTB pulling high. */
+	fsleep(4 * USEC_PER_MSEC);
+
+	ret = clk_prepare_enable(ov2735->xclk);
+	if (ret) {
+		dev_err(ov2735->dev, "failed to enable clock\n");
+		goto err_regulator_off;
+	}
+
+	gpiod_set_value_cansleep(ov2735->reset_gpio, 0);
+	/* T5: delay from RSTB pulling high to first I2C command */
+	fsleep(5 * USEC_PER_MSEC);
+
+	return 0;
+
+err_regulator_off:
+	regulator_bulk_disable(ARRAY_SIZE(ov2735_supply_name), ov2735->supplies);
+	return ret;
+}
+
+static int ov2735_power_off(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct ov2735 *ov2735 = to_ov2735(sd);
+
+	gpiod_set_value_cansleep(ov2735->enable_gpio, 0);
+	clk_disable_unprepare(ov2735->xclk);
+	gpiod_set_value_cansleep(ov2735->reset_gpio, 1);
+	regulator_bulk_disable(ARRAY_SIZE(ov2735_supply_name), ov2735->supplies);
+
+	return 0;
+}
+
+static int ov2735_get_regulators(struct ov2735 *ov2735)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(ov2735_supply_name); i++)
+		ov2735->supplies[i].supply = ov2735_supply_name[i];
+
+	return devm_regulator_bulk_get(ov2735->dev,
+				       ARRAY_SIZE(ov2735_supply_name),
+				       ov2735->supplies);
+}
+
+static int ov2735_identify_module(struct ov2735 *ov2735)
+{
+	u64 chip_id;
+	int ret;
+
+	ret = ov2735_read(ov2735, OV2735_REG_CHIPID, &chip_id, NULL);
+	if (ret)
+		return dev_err_probe(ov2735->dev, ret, "failed to read chip id %x\n",
+				     OV2735_CHIPID);
+
+	if (chip_id != OV2735_CHIPID)
+		return dev_err_probe(ov2735->dev, -EIO, "chip id mismatch: %x!=%llx\n",
+				     OV2735_CHIPID, chip_id);
+
+	return 0;
+}
+
+static int ov2735_parse_endpoint(struct ov2735 *ov2735)
+{
+	struct fwnode_handle *fwnode = dev_fwnode(ov2735->dev);
+	struct v4l2_fwnode_endpoint bus_cfg = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY,
+	};
+	struct fwnode_handle *ep;
+	unsigned long link_freq_bitmap;
+	int ret;
+
+	ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
+	if (!ep)
+		return dev_err_probe(ov2735->dev, -ENXIO,
+				     "Failed to get next endpoint\n");
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
+	fwnode_handle_put(ep);
+	if (ret)
+		return ret;
+
+	if (bus_cfg.bus.mipi_csi2.num_data_lanes != 2) {
+		ret = dev_err_probe(ov2735->dev, -EINVAL,
+				    "only 2 data lanes are supported\n");
+		goto error_out;
+	}
+
+	ret = v4l2_link_freq_to_bitmap(ov2735->dev, bus_cfg.link_frequencies,
+				       bus_cfg.nr_of_link_frequencies,
+				       link_freq_menu_items,
+				       ARRAY_SIZE(link_freq_menu_items),
+				       &link_freq_bitmap);
+	if (ret) {
+		ret = dev_err_probe(ov2735->dev, -EINVAL,
+				    "only 420MHz frequency is available\n");
+		goto error_out;
+	}
+
+	ov2735->link_freq_index = __ffs(link_freq_bitmap);
+
+error_out:
+	v4l2_fwnode_endpoint_free(&bus_cfg);
+
+	return ret;
+};
+
+static int ov2735_probe(struct i2c_client *client)
+{
+	struct ov2735 *ov2735;
+	unsigned int xclk_freq;
+	int ret;
+
+	ov2735 = devm_kzalloc(&client->dev, sizeof(*ov2735), GFP_KERNEL);
+	if (!ov2735)
+		return -ENOMEM;
+
+	ov2735->dev = &client->dev;
+
+	v4l2_i2c_subdev_init(&ov2735->sd, client, &ov2735_subdev_ops);
+	ov2735->sd.internal_ops = &ov2735_internal_ops;
+
+	ov2735->cci = devm_cci_regmap_init_i2c(client, 8);
+	if (IS_ERR(ov2735->cci))
+		return dev_err_probe(ov2735->dev, PTR_ERR(ov2735->cci),
+				     "failed to initialize CCI\n");
+
+	/* Set Current page to 0 */
+	ov2735->current_page = 0;
+
+	ret = devm_mutex_init(ov2735->dev, &ov2735->page_lock);
+	if (ret)
+		return dev_err_probe(ov2735->dev, ret,
+				     "Failed to initialize lock\n");
+
+	/* Get system clock (xvclk) */
+	ov2735->xclk = devm_v4l2_sensor_clk_get(ov2735->dev, NULL);
+	if (IS_ERR(ov2735->xclk))
+		return dev_err_probe(ov2735->dev, PTR_ERR(ov2735->xclk),
+				     "failed to get xclk\n");
+
+	xclk_freq = clk_get_rate(ov2735->xclk);
+	if (xclk_freq != OV2735_XCLK_FREQ)
+		return dev_err_probe(ov2735->dev, -EINVAL,
+				     "xclk frequency not supported: %u Hz\n",
+				     xclk_freq);
+
+	ret = ov2735_get_regulators(ov2735);
+	if (ret)
+		return dev_err_probe(ov2735->dev, ret, "failed to get regulators\n");
+
+	ret = ov2735_parse_endpoint(ov2735);
+	if (ret)
+		return dev_err_probe(ov2735->dev, ret,
+				     "failed to parse endpoint configuration\n");
+
+	ov2735->reset_gpio = devm_gpiod_get_optional(ov2735->dev,
+						     "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ov2735->reset_gpio))
+		return dev_err_probe(ov2735->dev, PTR_ERR(ov2735->reset_gpio),
+				     "failed to get reset GPIO\n");
+
+	ov2735->enable_gpio = devm_gpiod_get_optional(ov2735->dev,
+						      "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(ov2735->enable_gpio))
+		return dev_err_probe(ov2735->dev, PTR_ERR(ov2735->enable_gpio),
+				     "failed to get enable GPIO\n");
+
+	ret = ov2735_power_on(ov2735->dev);
+	if (ret)
+		return ret;
+
+	ret = ov2735_identify_module(ov2735);
+	if (ret)
+		goto error_power_off;
+
+	ret = ov2735_init_controls(ov2735);
+	if (ret)
+		goto error_power_off;
+
+	/* Initialize subdev */
+	ov2735->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	ov2735->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
+	ov2735->pad.flags = MEDIA_PAD_FL_SOURCE;
+
+	ret = media_entity_pads_init(&ov2735->sd.entity, 1, &ov2735->pad);
+	if (ret) {
+		dev_err_probe(ov2735->dev, ret, "failed to init entity pads\n");
+		goto error_handler_free;
+	}
+
+	ov2735->sd.state_lock = ov2735->handler.lock;
+	ret = v4l2_subdev_init_finalize(&ov2735->sd);
+	if (ret) {
+		dev_err_probe(ov2735->dev, ret, "subdev init error\n");
+		goto error_media_entity;
+	}
+
+	devm_pm_runtime_set_active_enabled(ov2735->dev);
+	devm_pm_runtime_get_noresume(ov2735->dev);
+
+	ret = v4l2_async_register_subdev_sensor(&ov2735->sd);
+	if (ret) {
+		dev_err_probe(ov2735->dev, ret,
+			      "failed to register ov2735 sub-device\n");
+		goto error_subdev_cleanup;
+	}
+
+	return 0;
+
+error_subdev_cleanup:
+	v4l2_subdev_cleanup(&ov2735->sd);
+
+error_media_entity:
+	media_entity_cleanup(&ov2735->sd.entity);
+
+error_handler_free:
+	v4l2_ctrl_handler_free(ov2735->sd.ctrl_handler);
+
+error_power_off:
+	ov2735_power_off(ov2735->dev);
+
+	return ret;
+}
+
+static void ov2735_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ov2735 *ov2735 = to_ov2735(sd);
+
+	v4l2_async_unregister_subdev(sd);
+	v4l2_subdev_cleanup(&ov2735->sd);
+	media_entity_cleanup(&sd->entity);
+	v4l2_ctrl_handler_free(ov2735->sd.ctrl_handler);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(ov2735_pm_ops,
+				 ov2735_power_off, ov2735_power_on, NULL);
+
+static const struct of_device_id ov2735_id[] = {
+	{ .compatible = "ovti,ov2735" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ov2735_id);
+
+static struct i2c_driver ov2735_driver = {
+	.driver = {
+		.name = "ov2735",
+		.pm = pm_ptr(&ov2735_pm_ops),
+		.of_match_table = ov2735_id,
+	},
+	.probe = ov2735_probe,
+	.remove = ov2735_remove,
+};
+module_i2c_driver(ov2735_driver);
+
+MODULE_DESCRIPTION("OV2735 Camera Sensor Driver");
+MODULE_AUTHOR("Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>");
+MODULE_AUTHOR("Himanshu Bhavani <himanshu.bhavani@siliconsignals.io>");
+MODULE_LICENSE("GPL");
-- 
2.34.1

Re: [PATCH v5 2/2] media: i2c: add ov2735 image sensor driver

[Andy Shevchenko]

On Thu, Jul 24, 2025 at 04:17:05PM +0530, Hardevsinh Palaniya wrote:
> Add a v4l2 subdevice driver for the Omnivision OV2735 sensor.
> 
> The Omnivision OV2735 is a 1/2.7-Inch CMOS image sensor with an
> active array size of 1920 x 1080.
> 
> The following features are supported:
> - Manual exposure an gain control support
> - vblank/hblank control support
> - Test pattern support control
> - Supported resolution: 1920 x 1080 @ 30fps (SGRBG10)

...

>  MAINTAINERS                |    9 +

This should be started as part of patch 1 as in between you will have a
dangling file, which is not recorded in MAINTAINERS.

...

> + * Inspired from ov8858, imx219, imx283 camera drivers

Missing period at the end.

...

> +#include <linux/array_size.h>

+ bitops.h

> +#include <linux/clk.h>
> +#include <linux/container_of.h>
> +#include <linux/delay.h>
> +#include <linux/device/devres.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/property.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/units.h>
> +#include <linux/types.h>

> +#include <vdso/time64.h>

We do not include vdso in the (regular) drivers. Use linux/time.h.

...

> +struct ov2735 {
> +	struct device *dev;

Do you need this? Can't it be derived from regmap cci below?

> +	struct regmap *cci;
> +	struct v4l2_subdev sd;
> +	struct media_pad pad;

> +	struct i2c_client *client;

Do you need this?

> +	struct clk *xclk;
> +	struct gpio_desc *reset_gpio;
> +	struct gpio_desc *enable_gpio;
> +	struct regulator_bulk_data supplies[ARRAY_SIZE(ov2735_supply_name)];
> +
> +	/* V4L2 Controls */
> +	struct v4l2_ctrl_handler handler;
> +	struct v4l2_ctrl *link_freq;
> +	struct v4l2_ctrl *pixel_rate;
> +	struct v4l2_ctrl *hblank;
> +	struct v4l2_ctrl *vblank;
> +	struct v4l2_ctrl *gain;
> +	struct v4l2_ctrl *exposure;
> +	struct v4l2_ctrl *test_pattern;
> +
> +	u32 link_freq_index;
> +
> +	u8 current_page;
> +	struct mutex page_lock;
> +};

...

> +static int ov2735_page_access(struct ov2735 *ov2735,
> +			      u32 reg, void *val, int *err, bool is_read)
> +{
> +	u8 page = (reg >> CCI_REG_PRIVATE_SHIFT) & 0xff;

' & 0xff' part is redundant.

> +	u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
> +	int ret = 0;

How is this assignment being used?

> +	if (err && *err)
> +		return *err;
> +
> +	mutex_lock(&ov2735->page_lock);
> +
> +	/* Perform page access before read/write */
> +	if (ov2735->current_page != page) {
> +		ret = cci_write(ov2735->cci, OV2735_REG_PAGE_SELECT, page, err);
> +		if (ret)
> +			goto err_mutex_unlock;
> +		ov2735->current_page = page;
> +	}
> +
> +	if (is_read)
> +		ret = cci_read(ov2735->cci, addr, (u64 *)val, err);
> +	else
> +		ret = cci_write(ov2735->cci, addr, *(u64 *)val, err);

Do you really need this castings?

> +
> +err_mutex_unlock:
> +	mutex_unlock(&ov2735->page_lock);
> +	return ret;

Hmm... Wouldn't be cleanup.h helpful here?

> +}

...

> +static int ov2735_write(struct ov2735 *ov2735, u32 reg, u64 val, int *err)
> +{
> +	return ov2735_page_access(ov2735, reg, (void *)&val, err, false);

Why casting?

> +}

...

> +static int ov2735_set_pll_ctrl(struct ov2735 *ov2735)
> +{
> +	struct ov2735_pll_parameters *pll_parameters;
> +	u8 pll_ctrl;
> +	u8 pll_outdiv;
> +	int ret = 0;
> +
> +	pll_parameters = &pll_configs[ov2735->link_freq_index];
> +
> +	/* BIT[7]: pll_clk_sel, BIT[6:2]: pll_nc, BIT[1:0]: pll_mc */
> +	pll_ctrl = ((pll_parameters->pll_nc << 2) |
> +		    (pll_parameters->pll_mc << 0)) & OV2735_REG_PLL_ENABLE;

Logically better to wrap like this (yes, I know that it's slightly longer than 80):

	pll_ctrl = ((pll_parameters->pll_nc << 2) | (pll_parameters->pll_mc << 0)) &
		   OV2735_REG_PLL_ENABLE;

> +	pll_outdiv = pll_parameters->pll_outdiv;
> +
> +	ov2735_write(ov2735, OV2735_REG_PLL_CTRL, pll_ctrl, &ret);

> +	ov2735_write(ov2735, OV2735_REG_PLL_OUTDIV, pll_outdiv, &ret);
> +
> +	return ret;
> +}

...

> +	/* Apply format settings. */

> +	/* Apply customized values from user */

Define a single style for one-line comments and use it everywhere consistently.

> +		goto error_power_off;

...

> +	devm_pm_runtime_set_active_enabled(ov2735->dev);
> +	devm_pm_runtime_get_noresume(ov2735->dev);

No error checks? What's the point to use devm and what will happen if the first
fails, for example?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 2/2] media: i2c: add ov2735 image sensor driver

[Hardevsinh Palaniya]

> On Thu, Jul 24, 2025 at 04:17:05PM +0530, Hardevsinh Palaniya wrote:
> > Add a v4l2 subdevice driver for the Omnivision OV2735 sensor.
> >
> > The Omnivision OV2735 is a 1/2.7-Inch CMOS image sensor with an
> > active array size of 1920 x 1080.
> >
> > The following features are supported:
> > - Manual exposure an gain control support
> > - vblank/hblank control support
> > - Test pattern support control
> > - Supported resolution: 1920 x 1080 @ 30fps (SGRBG10)
> 
> ...
> 
> >  MAINTAINERS                |    9 +
> 
> This should be started as part of patch 1 as in between you will have a
> dangling file, which is not recorded in MAINTAINERS.
> 
> ...
> 
> > + * Inspired from ov8858, imx219, imx283 camera drivers
> 
> Missing period at the end.
> 
> ...
> 
> > +#include <linux/array_size.h>
> 
> + bitops.h

Why??
 
> > +#include <linux/clk.h>
> > +#include <linux/container_of.h>
> > +#include <linux/delay.h>
> > +#include <linux/device/devres.h>
> > +#include <linux/err.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/property.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <linux/units.h>
> > +#include <linux/types.h>
> 
> > +#include <vdso/time64.h>
> 
> We do not include vdso in the (regular) drivers. Use linux/time.h.
> 
> ...
> 
> > +struct ov2735 {
> > +     struct device *dev;
> 
> Do you need this? Can't it be derived from regmap cci below?

I prefer keeping the dev pointer directly in the struct for simplicity
and better readability. Using regmap_get_device(ov2735->cci) adds an 
unnecessary level of indirection, especially since dev is frequently 
used for logging, error handling, and regulator/device tree access. 
I would prefer to retain it. 

> > +     struct regmap *cci;
> > +     struct v4l2_subdev sd;
> > +     struct media_pad pad;
> 
> > +     struct i2c_client *client;
> 
> Do you need this?
> 
> > +     struct clk *xclk;
> > +     struct gpio_desc *reset_gpio;
> > +     struct gpio_desc *enable_gpio;
> > +     struct regulator_bulk_data supplies[ARRAY_SIZE(ov2735_supply_name)];
> > +
> > +     /* V4L2 Controls */
> > +     struct v4l2_ctrl_handler handler;
> > +     struct v4l2_ctrl *link_freq;
> > +     struct v4l2_ctrl *pixel_rate;
> > +     struct v4l2_ctrl *hblank;
> > +     struct v4l2_ctrl *vblank;
> > +     struct v4l2_ctrl *gain;
> > +     struct v4l2_ctrl *exposure;
> > +     struct v4l2_ctrl *test_pattern;
> > +
> > +     u32 link_freq_index;
> > +
> > +     u8 current_page;
> > +     struct mutex page_lock;
> > +};
> 
> ...
> 
> > +static int ov2735_page_access(struct ov2735 *ov2735,
> > +                           u32 reg, void *val, int *err, bool is_read)
> > +{
> > +     u8 page = (reg >> CCI_REG_PRIVATE_SHIFT) & 0xff;
> 
> ' & 0xff' part is redundant.
> 
> > +     u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
> > +     int ret = 0;
> 
> How is this assignment being used?
> 
> > +     if (err && *err)
> > +             return *err;
> > +
> > +     mutex_lock(&ov2735->page_lock);
> > +
> > +     /* Perform page access before read/write */
> > +     if (ov2735->current_page != page) {
> > +             ret = cci_write(ov2735->cci, OV2735_REG_PAGE_SELECT, page, err);
> > +             if (ret)
> > +                     goto err_mutex_unlock;
> > +             ov2735->current_page = page;
> > +     }
> > +
> > +     if (is_read)
> > +             ret = cci_read(ov2735->cci, addr, (u64 *)val, err);
> > +     else
> > +             ret = cci_write(ov2735->cci, addr, *(u64 *)val, err);
> 
> Do you really need this castings?

Do you really think this casting is unnecessary?

Please check the definitions of cci_read/write

without this, we can't even build the driver.

> > +
> > +err_mutex_unlock:
> > +     mutex_unlock(&ov2735->page_lock);
> > +     return ret;
> 
> Hmm... Wouldn't be cleanup.h helpful here?
>
> > +}
> 
> ...
> 
> > +static int ov2735_write(struct ov2735 *ov2735, u32 reg, u64 val, int *err)
> > +{
> > +     return ov2735_page_access(ov2735, reg, (void *)&val, err, false);
> 
> Why casting?
> 
> > +}
> 
> ...
> 
> > +static int ov2735_set_pll_ctrl(struct ov2735 *ov2735)
> > +{
> > +     struct ov2735_pll_parameters *pll_parameters;
> > +     u8 pll_ctrl;
> > +     u8 pll_outdiv;
> > +     int ret = 0;
> > +
> > +     pll_parameters = &pll_configs[ov2735->link_freq_index];
> > +
> > +     /* BIT[7]: pll_clk_sel, BIT[6:2]: pll_nc, BIT[1:0]: pll_mc */
> > +     pll_ctrl = ((pll_parameters->pll_nc << 2) |
> > +                 (pll_parameters->pll_mc << 0)) & OV2735_REG_PLL_ENABLE;
> 
> Logically better to wrap like this (yes, I know that it's slightly longer than 80):
> 
>         pll_ctrl = ((pll_parameters->pll_nc << 2) | (pll_parameters->pll_mc << 0)) &
>                    OV2735_REG_PLL_ENABLE;
 
Will do.

Could you please clarify what you mean by "logically better" in this context?

> > +     pll_outdiv = pll_parameters->pll_outdiv;
> > +
> > +     ov2735_write(ov2735, OV2735_REG_PLL_CTRL, pll_ctrl, &ret);
> 
> > +     ov2735_write(ov2735, OV2735_REG_PLL_OUTDIV, pll_outdiv, &ret);
> > +
> > +     return ret;
> > +}
> 
> ...
> 
> > +     /* Apply format settings. */
> 
> > +     /* Apply customized values from user */
> 
> Define a single style for one-line comments and use it everywhere consistently.

Are you referring to the period at the end of the comment?
 
> > +             goto error_power_off;
> 
> ...
> 
> > +     devm_pm_runtime_set_active_enabled(ov2735->dev);
> > +     devm_pm_runtime_get_noresume(ov2735->dev);
> 
> No error checks? What's the point to use devm and what will happen if the first
> fails, for example?
> 
> --
> With Best Regards,
> Andy Shevchenko

With all due respect,

I completely understand and appreciate the need for multiple rounds of review.
However, where feasible, it would be helpful to receive style-related and 
non-blocking comments earlier in the review process. Iterating on minor issues
in later versions, especially ones that could have been addressed together 
earlier, can become a bit frustrating at times. I hope you can understand this 
perspective.

Once again, thank you for your time and effort in helping improve the quality
of the driver.

Best Regards,
Hardev    

Re: [PATCH v5 2/2] media: i2c: add ov2735 image sensor driver

[Kieran Bingham]

Quoting Hardevsinh Palaniya (2025-07-25 06:55:23)
<snip>
> > > +static int ov2735_page_access(struct ov2735 *ov2735,
> > > +�������������������������� u32 reg, void *val, int *err, bool is_read)
> > > +{
> > > +���� u8 page = (reg >> CCI_REG_PRIVATE_SHIFT) & 0xff;
> > 
> > ' & 0xff' part is redundant.
> > 
> > > +���� u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
> > > +���� int ret = 0;
> > 
> > How is this assignment being used?
> > 
> > > +���� if (err && *err)
> > > +������������ return *err;
> > > +
> > > +���� mutex_lock(&ov2735->page_lock);
> > > +
> > > +���� /* Perform page access before read/write */
> > > +���� if (ov2735->current_page != page) {
> > > +������������ ret = cci_write(ov2735->cci, OV2735_REG_PAGE_SELECT, page, err);
> > > +������������ if (ret)
> > > +�������������������� goto err_mutex_unlock;
> > > +������������ ov2735->current_page = page;
> > > +���� }
> > > +
> > > +���� if (is_read)
> > > +������������ ret = cci_read(ov2735->cci, addr, (u64 *)val, err);
> > > +���� else
> > > +������������ ret = cci_write(ov2735->cci, addr, *(u64 *)val, err);
> > 
> > Do you really need this castings?
> 
> Do you really think this casting is unnecessary?
> 

Yes? Well quite probably - I haven't checked myself yet but ..


> Please check the definitions of cci_read/write
> 
> without this, we can't even build the driver.

How about ... changing the function prototype of ov2735_page_access ?

Then you might be able to build without casts ?


> > > +err_mutex_unlock:
> > > +���� mutex_unlock(&ov2735->page_lock);
> > > +���� return ret;
> > 
> > Hmm... Wouldn't be cleanup.h helpful here?
> >
> > > +}
> > 
> > ...
> > 
> > > +static int ov2735_write(struct ov2735 *ov2735, u32 reg, u64 val, int *err)
> > > +{
> > > +���� return ov2735_page_access(ov2735, reg, (void *)&val, err, false);
> > 
> > Why casting?
> > 
> > > +}
> > 
> > ...

<snip>

> > > +���� /* Apply format settings. */
> > 
> > > +���� /* Apply customized values from user */
> > 
> > Define a single style for one-line comments and use it everywhere consistently.
> 
> Are you referring to the period at the end of the comment?
>  
> > > +������������ goto error_power_off;
> > 
> > ...
> > 
> > > +���� devm_pm_runtime_set_active_enabled(ov2735->dev);
> > > +���� devm_pm_runtime_get_noresume(ov2735->dev);
> > 
> > No error checks? What's the point to use devm and what will happen if the first
> > fails, for example?
> > 
> > --
> > With Best Regards,
> > Andy Shevchenko
> 
> With all due respect,
> 
> I completely understand and appreciate the need for multiple rounds of review.
> However, where feasible, it would be helpful to receive style-related and 
> non-blocking comments earlier in the review process. Iterating on minor issues
> in later versions, especially ones that could have been addressed together 
> earlier, can become a bit frustrating at times. I hope you can understand this 
> perspective.

I certainly understand that public patch review can be slow and tedious
at times, but please remember that unless you have paid Andy to review
this work, there are no contractual 'requirements' on which bits get
reviewed first. All reviews are helpful, whereever they come in - and
the goal here is to get as many eyes on code as possible to support high
quality code being maintained in the linux kernel.


Perhaps one path to speed this up in the future might be if you might
find some time to read more kernel code and also review some other
kernel patches publicly as well. It might accelerate/help you learn the
linux coding style sooner to avoid some cycles, and provide more eyes
where we need them in the community.

Regards
--
Kieran


> Once again, thank you for your time and effort in helping improve the quality
> of the driver.
> 
> Best Regards,
> Hardev

Re: [PATCH v5 2/2] media: i2c: add ov2735 image sensor driver

[Hardevsinh Palaniya]

> Quoting Hardevsinh Palaniya (2025-07-25 06:55:23)
> <snip>
> > > > +static int ov2735_page_access(struct ov2735 *ov2735,
> > > > +�������������������������� u32 reg, void *val, int *err, bool is_read)
> > > > +{
> > > > +���� u8 page = (reg >> CCI_REG_PRIVATE_SHIFT) & 0xff;
> > >
> > > ' & 0xff' part is redundant.
> > >
> > > > +���� u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
> > > > +���� int ret = 0;
> > >
> > > How is this assignment being used?
> > >
> > > > +���� if (err && *err)
> > > > +������������ return *err;
> > > > +
> > > > +���� mutex_lock(&ov2735->page_lock);
> > > > +
> > > > +���� /* Perform page access before read/write */
> > > > +���� if (ov2735->current_page != page) {
> > > > +������������ ret = cci_write(ov2735->cci, OV2735_REG_PAGE_SELECT, page, err);
> > > > +������������ if (ret)
> > > > +�������������������� goto err_mutex_unlock;
> > > > +������������ ov2735->current_page = page;
> > > > +���� }
> > > > +
> > > > +���� if (is_read)
> > > > +������������ ret = cci_read(ov2735->cci, addr, (u64 *)val, err);
> > > > +���� else
> > > > +������������ ret = cci_write(ov2735->cci, addr, *(u64 *)val, err);
> > >
> > > Do you really need this castings?
> >
> > Do you really think this casting is unnecessary?
> >
> 
> Yes? Well quite probably - I haven't checked myself yet but ..
> 
> 
> > Please check the definitions of cci_read/write
> >
> > without this, we can't even build the driver.
> 
> How about ... changing the function prototype of ov2735_page_access ?

Of course, changing the function prototype would work.

My intention is to keep a single ov2735_page_access() function that can
handle both read and write operations. The cci_read() function expects 
a u64 *, whereas cci_write() expects a u64 value. To support both cases
within one function, I’ve used a void *val and cast it appropriately 
depending on the operation.

If we were to remove the casting, we would need to split this into two
separate functions, one for read and one for write, even though the only 
difference between them would be a single line. I’d prefer to avoid that
redundancy and keep the code compact. 

Let me know if you see a better way to handle this without duplicating
the logic. 

Best Regards,
Hardev

Re: [PATCH v5 2/2] media: i2c: add ov2735 image sensor driver

[Laurent Pinchart]

On Sat, Jul 26, 2025 at 06:06:05AM +0000, Hardevsinh Palaniya wrote:
> > Quoting Hardevsinh Palaniya (2025-07-25 06:55:23)
> > <snip>
> > > > > +static int ov2735_page_access(struct ov2735 *ov2735,
> > > > > +�������������������������� u32 reg, void *val, int *err, bool is_read)
> > > > > +{
> > > > > +���� u8 page = (reg >> CCI_REG_PRIVATE_SHIFT) & 0xff;
> > > >
> > > > ' & 0xff' part is redundant.
> > > >
> > > > > +���� u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
> > > > > +���� int ret = 0;
> > > >
> > > > How is this assignment being used?
> > > >
> > > > > +���� if (err && *err)
> > > > > +������������ return *err;
> > > > > +
> > > > > +���� mutex_lock(&ov2735->page_lock);
> > > > > +
> > > > > +���� /* Perform page access before read/write */
> > > > > +���� if (ov2735->current_page != page) {
> > > > > +������������ ret = cci_write(ov2735->cci, OV2735_REG_PAGE_SELECT, page, err);
> > > > > +������������ if (ret)
> > > > > +�������������������� goto err_mutex_unlock;
> > > > > +������������ ov2735->current_page = page;
> > > > > +���� }
> > > > > +
> > > > > +���� if (is_read)
> > > > > +������������ ret = cci_read(ov2735->cci, addr, (u64 *)val, err);
> > > > > +���� else
> > > > > +������������ ret = cci_write(ov2735->cci, addr, *(u64 *)val, err);
> > > >
> > > > Do you really need this castings?
> > >
> > > Do you really think this casting is unnecessary?
> > >
> > 
> > Yes? Well quite probably - I haven't checked myself yet but ..
> > 
> > 
> > > Please check the definitions of cci_read/write
> > >
> > > without this, we can't even build the driver.
> > 
> > How about ... changing the function prototype of ov2735_page_access ?
> 
> Of course, changing the function prototype would work.
> 
> My intention is to keep a single ov2735_page_access() function that can
> handle both read and write operations. The cci_read() function expects 
> a u64 *, whereas cci_write() expects a u64 value. To support both cases
> within one function, I’ve used a void *val and cast it appropriately 
> depending on the operation.
> 
> If we were to remove the casting, we would need to split this into two
> separate functions, one for read and one for write, even though the only 
> difference between them would be a single line. I’d prefer to avoid that
> redundancy and keep the code compact. 
> 
> Let me know if you see a better way to handle this without duplicating
> the logic. 

Move the cci_read() and cci_write() calls from the bottom of
ov2735_page_access() to ov2735_read() and ov2735_write() respectively.

-- 
Regards,

Laurent Pinchart

Re: [PATCH v5 2/2] media: i2c: add ov2735 image sensor driver

[Hardevsinh Palaniya]

Hi Andy,

I’ve made all the corrections as per your comments; only one point is pending. 
Please see below.

> > On Thu, Jul 24, 2025 at 04:17:05PM +0530, Hardevsinh Palaniya wrote:
> > > Add a v4l2 subdevice driver for the Omnivision OV2735 sensor.
> > >
> > > The Omnivision OV2735 is a 1/2.7-Inch CMOS image sensor with an
> > > active array size of 1920 x 1080.
> > >
> > > The following features are supported:
> > > - Manual exposure an gain control support
> > > - vblank/hblank control support
> > > - Test pattern support control
> > > - Supported resolution: 1920 x 1080 @ 30fps (SGRBG10)
> >
> > ...
> >
> > >  MAINTAINERS                |    9 +
> >
> > This should be started as part of patch 1 as in between you will have a
> > dangling file, which is not recorded in MAINTAINERS.
> >
> > ...
> >
> > > + * Inspired from ov8858, imx219, imx283 camera drivers
> >
> > Missing period at the end.
> >
> > ...
> >
> > > +#include <linux/array_size.h>
> >
> > + bitops.h
> 
> Why??
> 
> > > +#include <linux/clk.h>
> > > +#include <linux/container_of.h>
> > > +#include <linux/delay.h>
> > > +#include <linux/device/devres.h>
> > > +#include <linux/err.h>
> > > +#include <linux/gpio/consumer.h>
> > > +#include <linux/i2c.h>
> > > +#include <linux/module.h>
> > > +#include <linux/mutex.h>
> > > +#include <linux/pm_runtime.h>
> > > +#include <linux/property.h>
> > > +#include <linux/regulator/consumer.h>
> > > +#include <linux/units.h>
> > > +#include <linux/types.h>
> >
> > > +#include <vdso/time64.h>
> >
> > We do not include vdso in the (regular) drivers. Use linux/time.h.
> >
> > ...
> >
> > > +struct ov2735 {
> > > +     struct device *dev;
> >
> > Do you need this? Can't it be derived from regmap cci below?
> 
> I prefer keeping the dev pointer directly in the struct for simplicity
> and better readability. Using regmap_get_device(ov2735->cci) adds an
> unnecessary level of indirection, especially since dev is frequently
> used for logging, error handling, and regulator/device tree access.
> I would prefer to retain it.

Are you okay with this approach, or do you still prefer to remove it?

Best Regards,
Hardev