media: i2c: Add imx412 camera sensor driver

Add a v4l2 sub-device driver for the Sony imx412 image sensor.
This is a camera sensor using the i2c bus for control and the
csi-2 bus for data.

The following features are supported:
- manual exposure and analog gain control support
- vblank/hblank/pixel rate/link freq control support
- supported resolution:
- 4056x3040 @ 30fps
- supported bayer order output:
- SRGGB10

[Sakari Ailus: Rebase on commit c802a4174beeb25cb539c806c9d0d3c0f61dfa53.]

Signed-off-by: Martina Krasteva <[e-mail]>
Acked-by: Daniele Alessandrelli <[e-mail]>
Acked-by: Paul J. Murphy <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

MAINTAINERS

···
 S:	Maintained
 T:	git git://linuxtv.org/media_tree.git
 F:	Documentation/devicetree/bindings/media/i2c/sony,imx412.yaml
+F:	drivers/media/i2c/imx412.c
 
 SONY MEMORYSTICK SUBSYSTEM
 M:	Maxim Levitsky <[e-mail]>

drivers/media/i2c/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called imx355.
 
+config VIDEO_IMX412
+	tristate "Sony IMX412 sensor support"
+	depends on OF_GPIO
+	depends on I2C && VIDEO_V4L2
+	select VIDEO_V4L2_SUBDEV_API
+	select MEDIA_CONTROLLER
+	select V4L2_FWNODE
+	help
+	  This is a Video4Linux2 sensor driver for the Sony
+	  IMX412 camera.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called imx412.
+
 config VIDEO_OV02A10
 	tristate "OmniVision OV02A10 sensor support"
 	depends on VIDEO_V4L2 && I2C

drivers/media/i2c/Makefile

···
 obj-$(CONFIG_VIDEO_IMX334)	+= imx334.o
 obj-$(CONFIG_VIDEO_IMX335)	+= imx335.o
 obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
+obj-$(CONFIG_VIDEO_IMX412)	+= imx412.o
 obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
 obj-$(CONFIG_VIDEO_MAX9271_LIB)	+= max9271.o
 obj-$(CONFIG_VIDEO_RDACM20)	+= rdacm20.o
 obj-$(CONFIG_VIDEO_RDACM21)	+= rdacm21.o
 obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
-
 obj-$(CONFIG_SDR_MAX2175) += max2175.o

drivers/media/i2c/imx412.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Sony imx412 Camera Sensor Driver
+ *
+ * Copyright (C) 2021 Intel Corporation
+ */
+#include <asm/unaligned.h>
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+/* Streaming Mode */
+#define IMX412_REG_MODE_SELECT	0x0100
+#define IMX412_MODE_STANDBY	0x00
+#define IMX412_MODE_STREAMING	0x01
+
+/* Lines per frame */
+#define IMX412_REG_LPFR		0x0340
+
+/* Chip ID */
+#define IMX412_REG_ID		0x0016
+#define IMX412_ID		0x577
+
+/* Exposure control */
+#define IMX412_REG_EXPOSURE_CIT	0x0202
+#define IMX412_EXPOSURE_MIN	8
+#define IMX412_EXPOSURE_OFFSET	22
+#define IMX412_EXPOSURE_STEP	1
+#define IMX412_EXPOSURE_DEFAULT	0x0648
+
+/* Analog gain control */
+#define IMX412_REG_AGAIN	0x0204
+#define IMX412_AGAIN_MIN	0
+#define IMX412_AGAIN_MAX	978
+#define IMX412_AGAIN_STEP	1
+#define IMX412_AGAIN_DEFAULT	0
+
+/* Group hold register */
+#define IMX412_REG_HOLD		0x0104
+
+/* Input clock rate */
+#define IMX412_INCLK_RATE	24000000
+
+/* CSI2 HW configuration */
+#define IMX412_LINK_FREQ	600000000
+#define IMX412_NUM_DATA_LANES	4
+
+#define IMX412_REG_MIN		0x00
+#define IMX412_REG_MAX		0xffff
+
+/**
+ * struct imx412_reg - imx412 sensor register
+ * @address: Register address
+ * @val: Register value
+ */
+struct imx412_reg {
+	u16 address;
+	u8 val;
+};
+
+/**
+ * struct imx412_reg_list - imx412 sensor register list
+ * @num_of_regs: Number of registers in the list
+ * @regs: Pointer to register list
+ */
+struct imx412_reg_list {
+	u32 num_of_regs;
+	const struct imx412_reg *regs;
+};
+
+/**
+ * struct imx412_mode - imx412 sensor mode structure
+ * @width: Frame width
+ * @height: Frame height
+ * @code: Format code
+ * @hblank: Horizontal blanking in lines
+ * @vblank: Vertical blanking in lines
+ * @vblank_min: Minimum vertical blanking in lines
+ * @vblank_max: Maximum vertical blanking in lines
+ * @pclk: Sensor pixel clock
+ * @link_freq_idx: Link frequency index
+ * @reg_list: Register list for sensor mode
+ */
+struct imx412_mode {
+	u32 width;
+	u32 height;
+	u32 code;
+	u32 hblank;
+	u32 vblank;
+	u32 vblank_min;
+	u32 vblank_max;
+	u64 pclk;
+	u32 link_freq_idx;
+	struct imx412_reg_list reg_list;
+};
+
+/**
+ * struct imx412 - imx412 sensor device structure
+ * @dev: Pointer to generic device
+ * @client: Pointer to i2c client
+ * @sd: V4L2 sub-device
+ * @pad: Media pad. Only one pad supported
+ * @reset_gpio: Sensor reset gpio
+ * @inclk: Sensor input clock
+ * @ctrl_handler: V4L2 control handler
+ * @link_freq_ctrl: Pointer to link frequency control
+ * @pclk_ctrl: Pointer to pixel clock control
+ * @hblank_ctrl: Pointer to horizontal blanking control
+ * @vblank_ctrl: Pointer to vertical blanking control
+ * @exp_ctrl: Pointer to exposure control
+ * @again_ctrl: Pointer to analog gain control
+ * @vblank: Vertical blanking in lines
+ * @cur_mode: Pointer to current selected sensor mode
+ * @mutex: Mutex for serializing sensor controls
+ * @streaming: Flag indicating streaming state
+ */
+struct imx412 {
+	struct device *dev;
+	struct i2c_client *client;
+	struct v4l2_subdev sd;
+	struct media_pad pad;
+	struct gpio_desc *reset_gpio;
+	struct clk *inclk;
+	struct v4l2_ctrl_handler ctrl_handler;
+	struct v4l2_ctrl *link_freq_ctrl;
+	struct v4l2_ctrl *pclk_ctrl;
+	struct v4l2_ctrl *hblank_ctrl;
+	struct v4l2_ctrl *vblank_ctrl;
+	struct {
+		struct v4l2_ctrl *exp_ctrl;
+		struct v4l2_ctrl *again_ctrl;
+	};
+	u32 vblank;
+	const struct imx412_mode *cur_mode;
+	struct mutex mutex;
+	bool streaming;
+};
+
+static const s64 link_freq[] = {
+	IMX412_LINK_FREQ,
+};
+
+/* Sensor mode registers */
+static const struct imx412_reg mode_4056x3040_regs[] = {
+	{0x0136, 0x18},
+	{0x0137, 0x00},
+	{0x3c7e, 0x08},
+	{0x3c7f, 0x02},
+	{0x38a8, 0x1f},
+	{0x38a9, 0xff},
+	{0x38aa, 0x1f},
+	{0x38ab, 0xff},
+	{0x55d4, 0x00},
+	{0x55d5, 0x00},
+	{0x55d6, 0x07},
+	{0x55d7, 0xff},
+	{0x55e8, 0x07},
+	{0x55e9, 0xff},
+	{0x55ea, 0x00},
+	{0x55eb, 0x00},
+	{0x575c, 0x07},
+	{0x575d, 0xff},
+	{0x575e, 0x00},
+	{0x575f, 0x00},
+	{0x5764, 0x00},
+	{0x5765, 0x00},
+	{0x5766, 0x07},
+	{0x5767, 0xff},
+	{0x5974, 0x04},
+	{0x5975, 0x01},
+	{0x5f10, 0x09},
+	{0x5f11, 0x92},
+	{0x5f12, 0x32},
+	{0x5f13, 0x72},
+	{0x5f14, 0x16},
+	{0x5f15, 0xba},
+	{0x5f17, 0x13},
+	{0x5f18, 0x24},
+	{0x5f19, 0x60},
+	{0x5f1a, 0xe3},
+	{0x5f1b, 0xad},
+	{0x5f1c, 0x74},
+	{0x5f2d, 0x25},
+	{0x5f5c, 0xd0},
+	{0x6a22, 0x00},
+	{0x6a23, 0x1d},
+	{0x7ba8, 0x00},
+	{0x7ba9, 0x00},
+	{0x886b, 0x00},
+	{0x9002, 0x0a},
+	{0x9004, 0x1a},
+	{0x9214, 0x93},
+	{0x9215, 0x69},
+	{0x9216, 0x93},
+	{0x9217, 0x6b},
+	{0x9218, 0x93},
+	{0x9219, 0x6d},
+	{0x921a, 0x57},
+	{0x921b, 0x58},
+	{0x921c, 0x57},
+	{0x921d, 0x59},
+	{0x921e, 0x57},
+	{0x921f, 0x5a},
+	{0x9220, 0x57},
+	{0x9221, 0x5b},
+	{0x9222, 0x93},
+	{0x9223, 0x02},
+	{0x9224, 0x93},
+	{0x9225, 0x03},
+	{0x9226, 0x93},
+	{0x9227, 0x04},
+	{0x9228, 0x93},
+	{0x9229, 0x05},
+	{0x922a, 0x98},
+	{0x922b, 0x21},
+	{0x922c, 0xb2},
+	{0x922d, 0xdb},
+	{0x922e, 0xb2},
+	{0x922f, 0xdc},
+	{0x9230, 0xb2},
+	{0x9231, 0xdd},
+	{0x9232, 0xe2},
+	{0x9233, 0xe1},
+	{0x9234, 0xb2},
+	{0x9235, 0xe2},
+	{0x9236, 0xb2},
+	{0x9237, 0xe3},
+	{0x9238, 0xb7},
+	{0x9239, 0xb9},
+	{0x923a, 0xb7},
+	{0x923b, 0xbb},
+	{0x923c, 0xb7},
+	{0x923d, 0xbc},
+	{0x923e, 0xb7},
+	{0x923f, 0xc5},
+	{0x9240, 0xb7},
+	{0x9241, 0xc7},
+	{0x9242, 0xb7},
+	{0x9243, 0xc9},
+	{0x9244, 0x98},
+	{0x9245, 0x56},
+	{0x9246, 0x98},
+	{0x9247, 0x55},
+	{0x9380, 0x00},
+	{0x9381, 0x62},
+	{0x9382, 0x00},
+	{0x9383, 0x56},
+	{0x9384, 0x00},
+	{0x9385, 0x52},
+	{0x9388, 0x00},
+	{0x9389, 0x55},
+	{0x938a, 0x00},
+	{0x938b, 0x55},
+	{0x938c, 0x00},
+	{0x938d, 0x41},
+	{0x5078, 0x01},
+	{0x0112, 0x0a},
+	{0x0113, 0x0a},
+	{0x0114, 0x03},
+	{0x0342, 0x11},
+	{0x0343, 0xa0},
+	{0x0340, 0x0d},
+	{0x0341, 0xda},
+	{0x3210, 0x00},
+	{0x0344, 0x00},
+	{0x0345, 0x00},
+	{0x0346, 0x00},
+	{0x0347, 0x00},
+	{0x0348, 0x0f},
+	{0x0349, 0xd7},
+	{0x034a, 0x0b},
+	{0x034b, 0xdf},
+	{0x00e3, 0x00},
+	{0x00e4, 0x00},
+	{0x00e5, 0x01},
+	{0x00fc, 0x0a},
+	{0x00fd, 0x0a},
+	{0x00fe, 0x0a},
+	{0x00ff, 0x0a},
+	{0xe013, 0x00},
+	{0x0220, 0x00},
+	{0x0221, 0x11},
+	{0x0381, 0x01},
+	{0x0383, 0x01},
+	{0x0385, 0x01},
+	{0x0387, 0x01},
+	{0x0900, 0x00},
+	{0x0901, 0x11},
+	{0x0902, 0x00},
+	{0x3140, 0x02},
+	{0x3241, 0x11},
+	{0x3250, 0x03},
+	{0x3e10, 0x00},
+	{0x3e11, 0x00},
+	{0x3f0d, 0x00},
+	{0x3f42, 0x00},
+	{0x3f43, 0x00},
+	{0x0401, 0x00},
+	{0x0404, 0x00},
+	{0x0405, 0x10},
+	{0x0408, 0x00},
+	{0x0409, 0x00},
+	{0x040a, 0x00},
+	{0x040b, 0x00},
+	{0x040c, 0x0f},
+	{0x040d, 0xd8},
+	{0x040e, 0x0b},
+	{0x040f, 0xe0},
+	{0x034c, 0x0f},
+	{0x034d, 0xd8},
+	{0x034e, 0x0b},
+	{0x034f, 0xe0},
+	{0x0301, 0x05},
+	{0x0303, 0x02},
+	{0x0305, 0x04},
+	{0x0306, 0x00},
+	{0x0307, 0xc8},
+	{0x0309, 0x0a},
+	{0x030b, 0x01},
+	{0x030d, 0x02},
+	{0x030e, 0x01},
+	{0x030f, 0x5e},
+	{0x0310, 0x00},
+	{0x0820, 0x12},
+	{0x0821, 0xc0},
+	{0x0822, 0x00},
+	{0x0823, 0x00},
+	{0x3e20, 0x01},
+	{0x3e37, 0x00},
+	{0x3f50, 0x00},
+	{0x3f56, 0x00},
+	{0x3f57, 0xe2},
+	{0x3c0a, 0x5a},
+	{0x3c0b, 0x55},
+	{0x3c0c, 0x28},
+	{0x3c0d, 0x07},
+	{0x3c0e, 0xff},
+	{0x3c0f, 0x00},
+	{0x3c10, 0x00},
+	{0x3c11, 0x02},
+	{0x3c12, 0x00},
+	{0x3c13, 0x03},
+	{0x3c14, 0x00},
+	{0x3c15, 0x00},
+	{0x3c16, 0x0c},
+	{0x3c17, 0x0c},
+	{0x3c18, 0x0c},
+	{0x3c19, 0x0a},
+	{0x3c1a, 0x0a},
+	{0x3c1b, 0x0a},
+	{0x3c1c, 0x00},
+	{0x3c1d, 0x00},
+	{0x3c1e, 0x00},
+	{0x3c1f, 0x00},
+	{0x3c20, 0x00},
+	{0x3c21, 0x00},
+	{0x3c22, 0x3f},
+	{0x3c23, 0x0a},
+	{0x3e35, 0x01},
+	{0x3f4a, 0x03},
+	{0x3f4b, 0xbf},
+	{0x3f26, 0x00},
+	{0x0202, 0x0d},
+	{0x0203, 0xc4},
+	{0x0204, 0x00},
+	{0x0205, 0x00},
+	{0x020e, 0x01},
+	{0x020f, 0x00},
+	{0x0210, 0x01},
+	{0x0211, 0x00},
+	{0x0212, 0x01},
+	{0x0213, 0x00},
+	{0x0214, 0x01},
+	{0x0215, 0x00},
+	{0xbcf1, 0x00},
+};
+
+/* Supported sensor mode configurations */
+static const struct imx412_mode supported_mode = {
+	.width = 4056,
+	.height = 3040,
+	.hblank = 456,
+	.vblank = 506,
+	.vblank_min = 506,
+	.vblank_max = 32420,
+	.pclk = 480000000,
+	.link_freq_idx = 0,
+	.code = MEDIA_BUS_FMT_SRGGB10_1X10,
+	.reg_list = {
+		.num_of_regs = ARRAY_SIZE(mode_4056x3040_regs),
+		.regs = mode_4056x3040_regs,
+	},
+};
+
+/**
+ * to_imx412() - imx412 V4L2 sub-device to imx412 device.
+ * @subdev: pointer to imx412 V4L2 sub-device
+ *
+ * Return: pointer to imx412 device
+ */
+static inline struct imx412 *to_imx412(struct v4l2_subdev *subdev)
+{
+	return container_of(subdev, struct imx412, sd);
+}
+
+/**
+ * imx412_read_reg() - Read registers.
+ * @imx412: pointer to imx412 device
+ * @reg: register address
+ * @len: length of bytes to read. Max supported bytes is 4
+ * @val: pointer to register value to be filled.
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_read_reg(struct imx412 *imx412, u16 reg, u32 len, u32 *val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&imx412->sd);
+	struct i2c_msg msgs[2] = {0};
+	u8 addr_buf[2] = {0};
+	u8 data_buf[4] = {0};
+	int ret;
+
+	if (WARN_ON(len > 4))
+		return -EINVAL;
+
+	put_unaligned_be16(reg, addr_buf);
+
+	/* Write register address */
+	msgs[0].addr = client->addr;
+	msgs[0].flags = 0;
+	msgs[0].len = ARRAY_SIZE(addr_buf);
+	msgs[0].buf = addr_buf;
+
+	/* Read data from register */
+	msgs[1].addr = client->addr;
+	msgs[1].flags = I2C_M_RD;
+	msgs[1].len = len;
+	msgs[1].buf = &data_buf[4 - len];
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (ret != ARRAY_SIZE(msgs))
+		return -EIO;
+
+	*val = get_unaligned_be32(data_buf);
+
+	return 0;
+}
+
+/**
+ * imx412_write_reg() - Write register
+ * @imx412: pointer to imx412 device
+ * @reg: register address
+ * @len: length of bytes. Max supported bytes is 4
+ * @val: register value
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_write_reg(struct imx412 *imx412, u16 reg, u32 len, u32 val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&imx412->sd);
+	u8 buf[6] = {0};
+
+	if (WARN_ON(len > 4))
+		return -EINVAL;
+
+	put_unaligned_be16(reg, buf);
+	put_unaligned_be32(val << (8 * (4 - len)), buf + 2);
+	if (i2c_master_send(client, buf, len + 2) != len + 2)
+		return -EIO;
+
+	return 0;
+}
+
+/**
+ * imx412_write_regs() - Write a list of registers
+ * @imx412: pointer to imx412 device
+ * @regs: list of registers to be written
+ * @len: length of registers array
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_write_regs(struct imx412 *imx412,
+			     const struct imx412_reg *regs, u32 len)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < len; i++) {
+		ret = imx412_write_reg(imx412, regs[i].address, 1, regs[i].val);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * imx412_update_controls() - Update control ranges based on streaming mode
+ * @imx412: pointer to imx412 device
+ * @mode: pointer to imx412_mode sensor mode
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_update_controls(struct imx412 *imx412,
+				  const struct imx412_mode *mode)
+{
+	int ret;
+
+	ret = __v4l2_ctrl_s_ctrl(imx412->link_freq_ctrl, mode->link_freq_idx);
+	if (ret)
+		return ret;
+
+	ret = __v4l2_ctrl_s_ctrl(imx412->hblank_ctrl, mode->hblank);
+	if (ret)
+		return ret;
+
+	return __v4l2_ctrl_modify_range(imx412->vblank_ctrl, mode->vblank_min,
+					mode->vblank_max, 1, mode->vblank);
+}
+
+/**
+ * imx412_update_exp_gain() - Set updated exposure and gain
+ * @imx412: pointer to imx412 device
+ * @exposure: updated exposure value
+ * @gain: updated analog gain value
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_update_exp_gain(struct imx412 *imx412, u32 exposure, u32 gain)
+{
+	u32 lpfr, shutter;
+	int ret;
+
+	lpfr = imx412->vblank + imx412->cur_mode->height;
+	shutter = lpfr - exposure;
+
+	dev_dbg(imx412->dev, "Set exp %u, analog gain %u, shutter %u, lpfr %u",
+		exposure, gain, shutter, lpfr);
+
+	ret = imx412_write_reg(imx412, IMX412_REG_HOLD, 1, 1);
+	if (ret)
+		return ret;
+
+	ret = imx412_write_reg(imx412, IMX412_REG_LPFR, 2, lpfr);
+	if (ret)
+		goto error_release_group_hold;
+
+	ret = imx412_write_reg(imx412, IMX412_REG_EXPOSURE_CIT, 2, shutter);
+	if (ret)
+		goto error_release_group_hold;
+
+	ret = imx412_write_reg(imx412, IMX412_REG_AGAIN, 2, gain);
+
+error_release_group_hold:
+	imx412_write_reg(imx412, IMX412_REG_HOLD, 1, 0);
+
+	return ret;
+}
+
+/**
+ * imx412_set_ctrl() - Set subdevice control
+ * @ctrl: pointer to v4l2_ctrl structure
+ *
+ * Supported controls:
+ * - V4L2_CID_VBLANK
+ * - cluster controls:
+ *   - V4L2_CID_ANALOGUE_GAIN
+ *   - V4L2_CID_EXPOSURE
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct imx412 *imx412 =
+		container_of(ctrl->handler, struct imx412, ctrl_handler);
+	u32 analog_gain;
+	u32 exposure;
+	int ret;
+
+	switch (ctrl->id) {
+	case V4L2_CID_VBLANK:
+		imx412->vblank = imx412->vblank_ctrl->val;
+
+		dev_dbg(imx412->dev, "Received vblank %u, new lpfr %u",
+			imx412->vblank,
+			imx412->vblank + imx412->cur_mode->height);
+
+		ret = __v4l2_ctrl_modify_range(imx412->exp_ctrl,
+					       IMX412_EXPOSURE_MIN,
+					       imx412->vblank +
+					       imx412->cur_mode->height -
+					       IMX412_EXPOSURE_OFFSET,
+					       1, IMX412_EXPOSURE_DEFAULT);
+		break;
+	case V4L2_CID_EXPOSURE:
+		/* Set controls only if sensor is in power on state */
+		if (!pm_runtime_get_if_in_use(imx412->dev))
+			return 0;
+
+		exposure = ctrl->val;
+		analog_gain = imx412->again_ctrl->val;
+
+		dev_dbg(imx412->dev, "Received exp %u, analog gain %u",
+			exposure, analog_gain);
+
+		ret = imx412_update_exp_gain(imx412, exposure, analog_gain);
+
+		pm_runtime_put(imx412->dev);
+
+		break;
+	default:
+		dev_err(imx412->dev, "Invalid control %d", ctrl->id);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+/* V4l2 subdevice control ops*/
+static const struct v4l2_ctrl_ops imx412_ctrl_ops = {
+	.s_ctrl = imx412_set_ctrl,
+};
+
+/**
+ * imx412_enum_mbus_code() - Enumerate V4L2 sub-device mbus codes
+ * @sd: pointer to imx412 V4L2 sub-device structure
+ * @sd_state: V4L2 sub-device configuration
+ * @code: V4L2 sub-device code enumeration need to be filled
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_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 = supported_mode.code;
+
+	return 0;
+}
+
+/**
+ * imx412_enum_frame_size() - Enumerate V4L2 sub-device frame sizes
+ * @sd: pointer to imx412 V4L2 sub-device structure
+ * @sd_state: V4L2 sub-device configuration
+ * @fsize: V4L2 sub-device size enumeration need to be filled
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_enum_frame_size(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_state *sd_state,
+				  struct v4l2_subdev_frame_size_enum *fsize)
+{
+	if (fsize->index > 0)
+		return -EINVAL;
+
+	if (fsize->code != supported_mode.code)
+		return -EINVAL;
+
+	fsize->min_width = supported_mode.width;
+	fsize->max_width = fsize->min_width;
+	fsize->min_height = supported_mode.height;
+	fsize->max_height = fsize->min_height;
+
+	return 0;
+}
+
+/**
+ * imx412_fill_pad_format() - Fill subdevice pad format
+ *                            from selected sensor mode
+ * @imx412: pointer to imx412 device
+ * @mode: pointer to imx412_mode sensor mode
+ * @fmt: V4L2 sub-device format need to be filled
+ */
+static void imx412_fill_pad_format(struct imx412 *imx412,
+				   const struct imx412_mode *mode,
+				   struct v4l2_subdev_format *fmt)
+{
+	fmt->format.width = mode->width;
+	fmt->format.height = mode->height;
+	fmt->format.code = mode->code;
+	fmt->format.field = V4L2_FIELD_NONE;
+	fmt->format.colorspace = V4L2_COLORSPACE_RAW;
+	fmt->format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
+	fmt->format.quantization = V4L2_QUANTIZATION_DEFAULT;
+	fmt->format.xfer_func = V4L2_XFER_FUNC_NONE;
+}
+
+/**
+ * imx412_get_pad_format() - Get subdevice pad format
+ * @sd: pointer to imx412 V4L2 sub-device structure
+ * @sd_state: V4L2 sub-device configuration
+ * @fmt: V4L2 sub-device format need to be set
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_get_pad_format(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_state *sd_state,
+				 struct v4l2_subdev_format *fmt)
+{
+	struct imx412 *imx412 = to_imx412(sd);
+
+	mutex_lock(&imx412->mutex);
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		struct v4l2_mbus_framefmt *framefmt;
+
+		framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
+		fmt->format = *framefmt;
+	} else {
+		imx412_fill_pad_format(imx412, imx412->cur_mode, fmt);
+	}
+
+	mutex_unlock(&imx412->mutex);
+
+	return 0;
+}
+
+/**
+ * imx412_set_pad_format() - Set subdevice pad format
+ * @sd: pointer to imx412 V4L2 sub-device structure
+ * @sd_state: V4L2 sub-device configuration
+ * @fmt: V4L2 sub-device format need to be set
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_set_pad_format(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_state *sd_state,
+				 struct v4l2_subdev_format *fmt)
+{
+	struct imx412 *imx412 = to_imx412(sd);
+	const struct imx412_mode *mode;
+	int ret = 0;
+
+	mutex_lock(&imx412->mutex);
+
+	mode = &supported_mode;
+	imx412_fill_pad_format(imx412, mode, fmt);
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		struct v4l2_mbus_framefmt *framefmt;
+
+		framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
+		*framefmt = fmt->format;
+	} else {
+		ret = imx412_update_controls(imx412, mode);
+		if (!ret)
+			imx412->cur_mode = mode;
+	}
+
+	mutex_unlock(&imx412->mutex);
+
+	return ret;
+}
+
+/**
+ * imx412_init_pad_cfg() - Initialize sub-device pad configuration
+ * @sd: pointer to imx412 V4L2 sub-device structure
+ * @sd_state: V4L2 sub-device configuration
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_init_pad_cfg(struct v4l2_subdev *sd,
+			       struct v4l2_subdev_state *sd_state)
+{
+	struct imx412 *imx412 = to_imx412(sd);
+	struct v4l2_subdev_format fmt = { 0 };
+
+	fmt.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
+	imx412_fill_pad_format(imx412, &supported_mode, &fmt);
+
+	return imx412_set_pad_format(sd, sd_state, &fmt);
+}
+
+/**
+ * imx412_start_streaming() - Start sensor stream
+ * @imx412: pointer to imx412 device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_start_streaming(struct imx412 *imx412)
+{
+	const struct imx412_reg_list *reg_list;
+	int ret;
+
+	/* Write sensor mode registers */
+	reg_list = &imx412->cur_mode->reg_list;
+	ret = imx412_write_regs(imx412, reg_list->regs,
+				reg_list->num_of_regs);
+	if (ret) {
+		dev_err(imx412->dev, "fail to write initial registers");
+		return ret;
+	}
+
+	/* Setup handler will write actual exposure and gain */
+	ret =  __v4l2_ctrl_handler_setup(imx412->sd.ctrl_handler);
+	if (ret) {
+		dev_err(imx412->dev, "fail to setup handler");
+		return ret;
+	}
+
+	/* Delay is required before streaming*/
+	usleep_range(7400, 8000);
+
+	/* Start streaming */
+	ret = imx412_write_reg(imx412, IMX412_REG_MODE_SELECT,
+			       1, IMX412_MODE_STREAMING);
+	if (ret) {
+		dev_err(imx412->dev, "fail to start streaming");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * imx412_stop_streaming() - Stop sensor stream
+ * @imx412: pointer to imx412 device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_stop_streaming(struct imx412 *imx412)
+{
+	return imx412_write_reg(imx412, IMX412_REG_MODE_SELECT,
+				1, IMX412_MODE_STANDBY);
+}
+
+/**
+ * imx412_set_stream() - Enable sensor streaming
+ * @sd: pointer to imx412 subdevice
+ * @enable: set to enable sensor streaming
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_set_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct imx412 *imx412 = to_imx412(sd);
+	int ret;
+
+	mutex_lock(&imx412->mutex);
+
+	if (imx412->streaming == enable) {
+		mutex_unlock(&imx412->mutex);
+		return 0;
+	}
+
+	if (enable) {
+		ret = pm_runtime_resume_and_get(imx412->dev);
+		if (ret)
+			goto error_unlock;
+
+		ret = imx412_start_streaming(imx412);
+		if (ret)
+			goto error_power_off;
+	} else {
+		imx412_stop_streaming(imx412);
+		pm_runtime_put(imx412->dev);
+	}
+
+	imx412->streaming = enable;
+
+	mutex_unlock(&imx412->mutex);
+
+	return 0;
+
+error_power_off:
+	pm_runtime_put(imx412->dev);
+error_unlock:
+	mutex_unlock(&imx412->mutex);
+
+	return ret;
+}
+
+/**
+ * imx412_detect() - Detect imx412 sensor
+ * @imx412: pointer to imx412 device
+ *
+ * Return: 0 if successful, -EIO if sensor id does not match
+ */
+static int imx412_detect(struct imx412 *imx412)
+{
+	int ret;
+	u32 val;
+
+	ret = imx412_read_reg(imx412, IMX412_REG_ID, 2, &val);
+	if (ret)
+		return ret;
+
+	if (val != IMX412_ID) {
+		dev_err(imx412->dev, "chip id mismatch: %x!=%x",
+			IMX412_ID, val);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+/**
+ * imx412_parse_hw_config() - Parse HW configuration and check if supported
+ * @imx412: pointer to imx412 device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_parse_hw_config(struct imx412 *imx412)
+{
+	struct fwnode_handle *fwnode = dev_fwnode(imx412->dev);
+	struct v4l2_fwnode_endpoint bus_cfg = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY
+	};
+	struct fwnode_handle *ep;
+	unsigned long rate;
+	unsigned int i;
+	int ret;
+
+	if (!fwnode)
+		return -ENXIO;
+
+	/* Request optional reset pin */
+	imx412->reset_gpio = devm_gpiod_get_optional(imx412->dev, "reset",
+						     GPIOD_OUT_LOW);
+	if (IS_ERR(imx412->reset_gpio)) {
+		dev_err(imx412->dev, "failed to get reset gpio %ld",
+			PTR_ERR(imx412->reset_gpio));
+		return PTR_ERR(imx412->reset_gpio);
+	}
+
+	/* Get sensor input clock */
+	imx412->inclk = devm_clk_get(imx412->dev, NULL);
+	if (IS_ERR(imx412->inclk)) {
+		dev_err(imx412->dev, "could not get inclk");
+		return PTR_ERR(imx412->inclk);
+	}
+
+	rate = clk_get_rate(imx412->inclk);
+	if (rate != IMX412_INCLK_RATE) {
+		dev_err(imx412->dev, "inclk frequency mismatch");
+		return -EINVAL;
+	}
+
+	ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
+	if (!ep)
+		return -ENXIO;
+
+	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 != IMX412_NUM_DATA_LANES) {
+		dev_err(imx412->dev,
+			"number of CSI2 data lanes %d is not supported",
+			bus_cfg.bus.mipi_csi2.num_data_lanes);
+		ret = -EINVAL;
+		goto done_endpoint_free;
+	}
+
+	if (!bus_cfg.nr_of_link_frequencies) {
+		dev_err(imx412->dev, "no link frequencies defined");
+		ret = -EINVAL;
+		goto done_endpoint_free;
+	}
+
+	for (i = 0; i < bus_cfg.nr_of_link_frequencies; i++)
+		if (bus_cfg.link_frequencies[i] == IMX412_LINK_FREQ)
+			goto done_endpoint_free;
+
+	ret = -EINVAL;
+
+done_endpoint_free:
+	v4l2_fwnode_endpoint_free(&bus_cfg);
+
+	return ret;
+}
+
+/* V4l2 subdevice ops */
+static const struct v4l2_subdev_video_ops imx412_video_ops = {
+	.s_stream = imx412_set_stream,
+};
+
+static const struct v4l2_subdev_pad_ops imx412_pad_ops = {
+	.init_cfg = imx412_init_pad_cfg,
+	.enum_mbus_code = imx412_enum_mbus_code,
+	.enum_frame_size = imx412_enum_frame_size,
+	.get_fmt = imx412_get_pad_format,
+	.set_fmt = imx412_set_pad_format,
+};
+
+static const struct v4l2_subdev_ops imx412_subdev_ops = {
+	.video = &imx412_video_ops,
+	.pad = &imx412_pad_ops,
+};
+
+/**
+ * imx412_power_on() - Sensor power on sequence
+ * @dev: pointer to i2c device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_power_on(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct imx412 *imx412 = to_imx412(sd);
+	int ret;
+
+	gpiod_set_value_cansleep(imx412->reset_gpio, 1);
+
+	ret = clk_prepare_enable(imx412->inclk);
+	if (ret) {
+		dev_err(imx412->dev, "fail to enable inclk");
+		goto error_reset;
+	}
+
+	usleep_range(1000, 1200);
+
+	return 0;
+
+error_reset:
+	gpiod_set_value_cansleep(imx412->reset_gpio, 0);
+
+	return ret;
+}
+
+/**
+ * imx412_power_off() - Sensor power off sequence
+ * @dev: pointer to i2c device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_power_off(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct imx412 *imx412 = to_imx412(sd);
+
+	gpiod_set_value_cansleep(imx412->reset_gpio, 0);
+
+	clk_disable_unprepare(imx412->inclk);
+
+	return 0;
+}
+
+/**
+ * imx412_init_controls() - Initialize sensor subdevice controls
+ * @imx412: pointer to imx412 device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_init_controls(struct imx412 *imx412)
+{
+	struct v4l2_ctrl_handler *ctrl_hdlr = &imx412->ctrl_handler;
+	const struct imx412_mode *mode = imx412->cur_mode;
+	u32 lpfr;
+	int ret;
+
+	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 6);
+	if (ret)
+		return ret;
+
+	/* Serialize controls with sensor device */
+	ctrl_hdlr->lock = &imx412->mutex;
+
+	/* Initialize exposure and gain */
+	lpfr = mode->vblank + mode->height;
+	imx412->exp_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+					     &imx412_ctrl_ops,
+					     V4L2_CID_EXPOSURE,
+					     IMX412_EXPOSURE_MIN,
+					     lpfr - IMX412_EXPOSURE_OFFSET,
+					     IMX412_EXPOSURE_STEP,
+					     IMX412_EXPOSURE_DEFAULT);
+
+	imx412->again_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+					       &imx412_ctrl_ops,
+					       V4L2_CID_ANALOGUE_GAIN,
+					       IMX412_AGAIN_MIN,
+					       IMX412_AGAIN_MAX,
+					       IMX412_AGAIN_STEP,
+					       IMX412_AGAIN_DEFAULT);
+
+	v4l2_ctrl_cluster(2, &imx412->exp_ctrl);
+
+	imx412->vblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+						&imx412_ctrl_ops,
+						V4L2_CID_VBLANK,
+						mode->vblank_min,
+						mode->vblank_max,
+						1, mode->vblank);
+
+	/* Read only controls */
+	imx412->pclk_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+					      &imx412_ctrl_ops,
+					      V4L2_CID_PIXEL_RATE,
+					      mode->pclk, mode->pclk,
+					      1, mode->pclk);
+
+	imx412->link_freq_ctrl = v4l2_ctrl_new_int_menu(ctrl_hdlr,
+							&imx412_ctrl_ops,
+							V4L2_CID_LINK_FREQ,
+							ARRAY_SIZE(link_freq) -
+							1,
+							mode->link_freq_idx,
+							link_freq);
+	if (imx412->link_freq_ctrl)
+		imx412->link_freq_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	imx412->hblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+						&imx412_ctrl_ops,
+						V4L2_CID_HBLANK,
+						IMX412_REG_MIN,
+						IMX412_REG_MAX,
+						1, mode->hblank);
+	if (imx412->hblank_ctrl)
+		imx412->hblank_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	if (ctrl_hdlr->error) {
+		dev_err(imx412->dev, "control init failed: %d",
+			ctrl_hdlr->error);
+		v4l2_ctrl_handler_free(ctrl_hdlr);
+		return ctrl_hdlr->error;
+	}
+
+	imx412->sd.ctrl_handler = ctrl_hdlr;
+
+	return 0;
+}
+
+/**
+ * imx412_probe() - I2C client device binding
+ * @client: pointer to i2c client device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_probe(struct i2c_client *client)
+{
+	struct imx412 *imx412;
+	int ret;
+
+	imx412 = devm_kzalloc(&client->dev, sizeof(*imx412), GFP_KERNEL);
+	if (!imx412)
+		return -ENOMEM;
+
+	imx412->dev = &client->dev;
+
+	/* Initialize subdev */
+	v4l2_i2c_subdev_init(&imx412->sd, client, &imx412_subdev_ops);
+
+	ret = imx412_parse_hw_config(imx412);
+	if (ret) {
+		dev_err(imx412->dev, "HW configuration is not supported");
+		return ret;
+	}
+
+	mutex_init(&imx412->mutex);
+
+	ret = imx412_power_on(imx412->dev);
+	if (ret) {
+		dev_err(imx412->dev, "failed to power-on the sensor");
+		goto error_mutex_destroy;
+	}
+
+	/* Check module identity */
+	ret = imx412_detect(imx412);
+	if (ret) {
+		dev_err(imx412->dev, "failed to find sensor: %d", ret);
+		goto error_power_off;
+	}
+
+	/* Set default mode to max resolution */
+	imx412->cur_mode = &supported_mode;
+	imx412->vblank = imx412->cur_mode->vblank;
+
+	ret = imx412_init_controls(imx412);
+	if (ret) {
+		dev_err(imx412->dev, "failed to init controls: %d", ret);
+		goto error_power_off;
+	}
+
+	/* Initialize subdev */
+	imx412->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	imx412->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
+
+	/* Initialize source pad */
+	imx412->pad.flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_pads_init(&imx412->sd.entity, 1, &imx412->pad);
+	if (ret) {
+		dev_err(imx412->dev, "failed to init entity pads: %d", ret);
+		goto error_handler_free;
+	}
+
+	ret = v4l2_async_register_subdev_sensor(&imx412->sd);
+	if (ret < 0) {
+		dev_err(imx412->dev,
+			"failed to register async subdev: %d", ret);
+		goto error_media_entity;
+	}
+
+	pm_runtime_set_active(imx412->dev);
+	pm_runtime_enable(imx412->dev);
+	pm_runtime_idle(imx412->dev);
+
+	return 0;
+
+error_media_entity:
+	media_entity_cleanup(&imx412->sd.entity);
+error_handler_free:
+	v4l2_ctrl_handler_free(imx412->sd.ctrl_handler);
+error_power_off:
+	imx412_power_off(imx412->dev);
+error_mutex_destroy:
+	mutex_destroy(&imx412->mutex);
+
+	return ret;
+}
+
+/**
+ * imx412_remove() - I2C client device unbinding
+ * @client: pointer to I2C client device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx412_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct imx412 *imx412 = to_imx412(sd);
+
+	v4l2_async_unregister_subdev(sd);
+	media_entity_cleanup(&sd->entity);
+	v4l2_ctrl_handler_free(sd->ctrl_handler);
+
+	pm_runtime_disable(&client->dev);
+	if (!pm_runtime_status_suspended(&client->dev))
+		imx412_power_off(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+
+	mutex_destroy(&imx412->mutex);
+
+	return 0;
+}
+
+static const struct dev_pm_ops imx412_pm_ops = {
+	SET_RUNTIME_PM_OPS(imx412_power_off, imx412_power_on, NULL)
+};
+
+static const struct of_device_id imx412_of_match[] = {
+	{ .compatible = "sony,imx412" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, imx412_of_match);
+
+static struct i2c_driver imx412_driver = {
+	.probe_new = imx412_probe,
+	.remove = imx412_remove,
+	.driver = {
+		.name = "imx412",
+		.pm = &imx412_pm_ops,
+		.of_match_table = imx412_of_match,
+	},
+};
+
+module_i2c_driver(imx412_driver);
+
+MODULE_DESCRIPTION("Sony imx412 sensor driver");
+MODULE_LICENSE("GPL");