Re: [PATCH v2 2/2] media: i2c: Add driver for Sony IMX219 sensor

[Sakari Ailus <sakari.ailus@iki.fi>]

Hi Andrey,

On Fri, Dec 27, 2019 at 03:21:14PM +0300, Andrey Konovalov wrote:
> From: Dave Stevenson <dave.stevenson@raspberrypi.com>
> 
> Adds a driver for the 8MPix Sony IMX219 CSI2 sensor.
> Whilst the sensor supports 2 or 4 CSI2 data lanes, this driver
> currently only supports 2 lanes.
> 8MPix @ 15fps, 1080P @ 30fps (cropped FOV), and 1640x1232 (2x2 binned)
> @ 30fps are currently supported.
> 
> Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
> Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
> ---
>  drivers/media/i2c/Kconfig  |   12 +
>  drivers/media/i2c/Makefile |    1 +
>  drivers/media/i2c/imx219.c | 1240 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 1253 insertions(+)
>  create mode 100644 drivers/media/i2c/imx219.c
> 
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index c68e002d26ea..6fa5af1f72b9 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -591,6 +591,18 @@ config VIDEO_IMX214
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called imx214.
>  
> +config VIDEO_IMX219
> +	tristate "Sony IMX219 sensor support"
> +	depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
> +	depends on MEDIA_CAMERA_SUPPORT

You can safely drop this line.

> +	select V4L2_FWNODE
> +	help
> +	  This is a Video4Linux2 sensor driver for the Sony
> +	  IMX219 camera.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called imx219.
> +
>  config VIDEO_IMX258
>  	tristate "Sony IMX258 sensor support"
>  	depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index c147bb9d28db..77bf7d0b691f 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -111,6 +111,7 @@ obj-$(CONFIG_VIDEO_OV2659)	+= ov2659.o
>  obj-$(CONFIG_VIDEO_TC358743)	+= tc358743.o
>  obj-$(CONFIG_VIDEO_HI556)	+= hi556.o
>  obj-$(CONFIG_VIDEO_IMX214)	+= imx214.o
> +obj-$(CONFIG_VIDEO_IMX219)	+= imx219.o
>  obj-$(CONFIG_VIDEO_IMX258)	+= imx258.o
>  obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
>  obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
> diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> new file mode 100644
> index 000000000000..28b55c61cd77
> --- /dev/null
> +++ b/drivers/media/i2c/imx219.c
> @@ -0,0 +1,1240 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * A V4L2 driver for Sony IMX219 cameras.
> + * Copyright (C) 2019, Raspberry Pi (Trading) Ltd
> + *
> + * Based on Sony imx258 camera driver
> + * Copyright (C) 2018 Intel Corporation
> + *
> + * DT / fwnode changes, and regulator / GPIO control taken from imx214 driver
> + * Copyright 2018 Qtechnology A/S
> + *
> + * Flip handling taken from the Sony IMX319 driver.
> + * Copyright (C) 2018 Intel Corporation
> + *
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-mediabus.h>
> +#include <asm/unaligned.h>
> +
> +#define IMX219_REG_VALUE_08BIT		1
> +#define IMX219_REG_VALUE_16BIT		2
> +
> +#define IMX219_REG_MODE_SELECT		0x0100
> +#define IMX219_MODE_STANDBY		0x00
> +#define IMX219_MODE_STREAMING		0x01
> +
> +/* Chip ID */
> +#define IMX219_REG_CHIP_ID		0x0000
> +#define IMX219_CHIP_ID			0x0219
> +
> +/* External clock frequency is 24.0M */
> +#define IMX219_XCLK_FREQ		24000000
> +
> +/* Pixel rate is fixed at 182.4M for all the modes */
> +#define IMX219_PIXEL_RATE		182400000
> +
> +/* V_TIMING internal */
> +#define IMX219_REG_VTS			0x0160
> +#define IMX219_VTS_15FPS		0x0dc6
> +#define IMX219_VTS_30FPS_1080P		0x06e3
> +#define IMX219_VTS_30FPS_BINNED		0x06e3
> +#define IMX219_VTS_MAX			0xffff
> +
> +#define IMX219_VBLANK_MIN		4
> +
> +/*Frame Length Line*/
> +#define IMX219_FLL_MIN			0x08a6
> +#define IMX219_FLL_MAX			0xffff
> +#define IMX219_FLL_STEP			1
> +#define IMX219_FLL_DEFAULT		0x0c98
> +
> +/* HBLANK control - read only */
> +#define IMX219_PPL_DEFAULT		3448
> +
> +/* Exposure control */
> +#define IMX219_REG_EXPOSURE		0x015a
> +#define IMX219_EXPOSURE_MIN		4
> +#define IMX219_EXPOSURE_STEP		1
> +#define IMX219_EXPOSURE_DEFAULT		0x640
> +#define IMX219_EXPOSURE_MAX		65535
> +
> +/* Analog gain control */
> +#define IMX219_REG_ANALOG_GAIN		0x0157
> +#define IMX219_ANA_GAIN_MIN		0
> +#define IMX219_ANA_GAIN_MAX		232
> +#define IMX219_ANA_GAIN_STEP		1
> +#define IMX219_ANA_GAIN_DEFAULT		0x0
> +
> +/* Digital gain control */
> +#define IMX219_REG_DIGITAL_GAIN		0x0158
> +#define IMX219_DGTL_GAIN_MIN		0x0100
> +#define IMX219_DGTL_GAIN_MAX		0x0fff
> +#define IMX219_DGTL_GAIN_DEFAULT	0x0100
> +#define IMX219_DGTL_GAIN_STEP		1
> +
> +#define IMX219_REG_ORIENTATION		0x0172
> +
> +/* Test Pattern Control */
> +#define IMX219_REG_TEST_PATTERN		0x0600
> +#define IMX219_TEST_PATTERN_DISABLE	0
> +#define IMX219_TEST_PATTERN_SOLID_COLOR	1
> +#define IMX219_TEST_PATTERN_COLOR_BARS	2
> +#define IMX219_TEST_PATTERN_GREY_COLOR	3
> +#define IMX219_TEST_PATTERN_PN9		4
> +
> +/* Test pattern colour components */
> +#define IMX219_REG_TESTP_RED		0x0602
> +#define IMX219_REG_TESTP_GREENR		0x0604
> +#define IMX219_REG_TESTP_BLUE		0x0606
> +#define IMX219_REG_TESTP_GREENB		0x0608
> +#define IMX219_TESTP_COLOUR_MIN		0
> +#define IMX219_TESTP_COLOUR_MAX		0x03ff
> +#define IMX219_TESTP_COLOUR_STEP	1
> +#define IMX219_TESTP_RED_DEFAULT	IMX219_TESTP_COLOUR_MAX
> +#define IMX219_TESTP_GREENR_DEFAULT	0
> +#define IMX219_TESTP_BLUE_DEFAULT	0
> +#define IMX219_TESTP_GREENB_DEFAULT	0
> +
> +struct imx219_reg {
> +	u16 address;
> +	u8 val;
> +};
> +
> +struct imx219_reg_list {
> +	unsigned int num_of_regs;
> +	const struct imx219_reg *regs;
> +};
> +
> +/* Mode : resolution and related config&values */
> +struct imx219_mode {
> +	/* Frame width */
> +	unsigned int width;
> +	/* Frame height */
> +	unsigned int height;
> +
> +	/* V-timing */
> +	unsigned int vts_def;
> +
> +	/* Default register values */
> +	struct imx219_reg_list reg_list;
> +};
> +
> +/*
> + * Register sets lifted off the i2C interface from the Raspberry Pi firmware
> + * driver.
> + * 3280x2464 = mode 2, 1920x1080 = mode 1, and 1640x1232 = mode 4.
> + */
> +static const struct imx219_reg mode_3280x2464_regs[] = {
> +	{0x0100, 0x00},
> +	{0x30eb, 0x0c},
> +	{0x30eb, 0x05},
> +	{0x300a, 0xff},
> +	{0x300b, 0xff},
> +	{0x30eb, 0x05},
> +	{0x30eb, 0x09},
> +	{0x0114, 0x01},
> +	{0x0128, 0x00},
> +	{0x012a, 0x18},
> +	{0x012b, 0x00},
> +	{0x0164, 0x00},
> +	{0x0165, 0x00},
> +	{0x0166, 0x0c},
> +	{0x0167, 0xcf},
> +	{0x0168, 0x00},
> +	{0x0169, 0x00},
> +	{0x016a, 0x09},
> +	{0x016b, 0x9f},
> +	{0x016c, 0x0c},
> +	{0x016d, 0xd0},
> +	{0x016e, 0x09},
> +	{0x016f, 0xa0},
> +	{0x0170, 0x01},
> +	{0x0171, 0x01},
> +	{0x0174, 0x00},
> +	{0x0175, 0x00},
> +	{0x018c, 0x0a},
> +	{0x018d, 0x0a},
> +	{0x0301, 0x05},
> +	{0x0303, 0x01},
> +	{0x0304, 0x03},
> +	{0x0305, 0x03},
> +	{0x0306, 0x00},
> +	{0x0307, 0x39},
> +	{0x0309, 0x0a},
> +	{0x030b, 0x01},
> +	{0x030c, 0x00},
> +	{0x030d, 0x72},
> +	{0x0624, 0x0c},
> +	{0x0625, 0xd0},
> +	{0x0626, 0x09},
> +	{0x0627, 0xa0},
> +	{0x455e, 0x00},
> +	{0x471e, 0x4b},
> +	{0x4767, 0x0f},
> +	{0x4750, 0x14},
> +	{0x4540, 0x00},
> +	{0x47b4, 0x14},
> +	{0x4713, 0x30},
> +	{0x478b, 0x10},
> +	{0x478f, 0x10},
> +	{0x4793, 0x10},
> +	{0x4797, 0x0e},
> +	{0x479b, 0x0e},
> +	{0x0162, 0x0d},
> +	{0x0163, 0x78},
> +};
> +
> +static const struct imx219_reg mode_1920_1080_regs[] = {
> +	{0x0100, 0x00},
> +	{0x30eb, 0x05},
> +	{0x30eb, 0x0c},
> +	{0x300a, 0xff},
> +	{0x300b, 0xff},
> +	{0x30eb, 0x05},
> +	{0x30eb, 0x09},
> +	{0x0114, 0x01},
> +	{0x0128, 0x00},
> +	{0x012a, 0x18},
> +	{0x012b, 0x00},
> +	{0x0162, 0x0d},
> +	{0x0163, 0x78},
> +	{0x0164, 0x02},
> +	{0x0165, 0xa8},
> +	{0x0166, 0x0a},
> +	{0x0167, 0x27},
> +	{0x0168, 0x02},
> +	{0x0169, 0xb4},
> +	{0x016a, 0x06},
> +	{0x016b, 0xeb},
> +	{0x016c, 0x07},
> +	{0x016d, 0x80},
> +	{0x016e, 0x04},
> +	{0x016f, 0x38},
> +	{0x0170, 0x01},
> +	{0x0171, 0x01},
> +	{0x0174, 0x00},
> +	{0x0175, 0x00},
> +	{0x018c, 0x0a},
> +	{0x018d, 0x0a},
> +	{0x0301, 0x05},
> +	{0x0303, 0x01},
> +	{0x0304, 0x03},
> +	{0x0305, 0x03},
> +	{0x0306, 0x00},
> +	{0x0307, 0x39},
> +	{0x0309, 0x0a},
> +	{0x030b, 0x01},
> +	{0x030c, 0x00},
> +	{0x030d, 0x72},
> +	{0x0624, 0x07},
> +	{0x0625, 0x80},
> +	{0x0626, 0x04},
> +	{0x0627, 0x38},
> +	{0x455e, 0x00},
> +	{0x471e, 0x4b},
> +	{0x4767, 0x0f},
> +	{0x4750, 0x14},
> +	{0x4540, 0x00},
> +	{0x47b4, 0x14},
> +	{0x4713, 0x30},
> +	{0x478b, 0x10},
> +	{0x478f, 0x10},
> +	{0x4793, 0x10},
> +	{0x4797, 0x0e},
> +	{0x479b, 0x0e},
> +	{0x0162, 0x0d},
> +	{0x0163, 0x78},
> +};
> +
> +static const struct imx219_reg mode_1640_1232_regs[] = {
> +	{0x0100, 0x00},
> +	{0x30eb, 0x0c},
> +	{0x30eb, 0x05},
> +	{0x300a, 0xff},
> +	{0x300b, 0xff},
> +	{0x30eb, 0x05},
> +	{0x30eb, 0x09},
> +	{0x0114, 0x01},
> +	{0x0128, 0x00},
> +	{0x012a, 0x18},
> +	{0x012b, 0x00},
> +	{0x0164, 0x00},
> +	{0x0165, 0x00},
> +	{0x0166, 0x0c},
> +	{0x0167, 0xcf},
> +	{0x0168, 0x00},
> +	{0x0169, 0x00},
> +	{0x016a, 0x09},
> +	{0x016b, 0x9f},
> +	{0x016c, 0x06},
> +	{0x016d, 0x68},
> +	{0x016e, 0x04},
> +	{0x016f, 0xd0},
> +	{0x0170, 0x01},
> +	{0x0171, 0x01},
> +	{0x0174, 0x01},
> +	{0x0175, 0x01},
> +	{0x018c, 0x0a},
> +	{0x018d, 0x0a},
> +	{0x0301, 0x05},
> +	{0x0303, 0x01},
> +	{0x0304, 0x03},
> +	{0x0305, 0x03},
> +	{0x0306, 0x00},
> +	{0x0307, 0x39},
> +	{0x0309, 0x0a},
> +	{0x030b, 0x01},
> +	{0x030c, 0x00},
> +	{0x030d, 0x72},
> +	{0x0624, 0x06},
> +	{0x0625, 0x68},
> +	{0x0626, 0x04},
> +	{0x0627, 0xd0},
> +	{0x455e, 0x00},
> +	{0x471e, 0x4b},
> +	{0x4767, 0x0f},
> +	{0x4750, 0x14},
> +	{0x4540, 0x00},
> +	{0x47b4, 0x14},
> +	{0x4713, 0x30},
> +	{0x478b, 0x10},
> +	{0x478f, 0x10},
> +	{0x4793, 0x10},
> +	{0x4797, 0x0e},
> +	{0x479b, 0x0e},
> +	{0x0162, 0x0d},
> +	{0x0163, 0x78},
> +};
> +
> +static const char * const imx219_test_pattern_menu[] = {
> +	"Disabled",
> +	"Color Bars",
> +	"Solid Color",
> +	"Grey Color Bars",
> +	"PN9"
> +};
> +
> +static const int imx219_test_pattern_val[] = {
> +	IMX219_TEST_PATTERN_DISABLE,
> +	IMX219_TEST_PATTERN_COLOR_BARS,
> +	IMX219_TEST_PATTERN_SOLID_COLOR,
> +	IMX219_TEST_PATTERN_GREY_COLOR,
> +	IMX219_TEST_PATTERN_PN9,
> +};
> +
> +/* regulator supplies */
> +static const char * const imx219_supply_name[] = {
> +	/* Supplies can be enabled in any order */
> +	"VANA",  /* Analog (2.8V) supply */
> +	"VDIG",  /* Digital Core (1.8V) supply */
> +	"VDDL",  /* IF (1.2V) supply */
> +};
> +
> +#define IMX219_NUM_SUPPLIES ARRAY_SIZE(imx219_supply_name)
> +
> +#define IMX219_XCLR_DELAY_MS 10	/* Initialisation delay after XCLR low->high */
> +
> +/* Mode configs */
> +static const struct imx219_mode supported_modes[] = {
> +	{
> +		/* 8MPix 15fps mode */
> +		.width = 3280,
> +		.height = 2464,
> +		.vts_def = IMX219_VTS_15FPS,
> +		.reg_list = {
> +			.num_of_regs = ARRAY_SIZE(mode_3280x2464_regs),
> +			.regs = mode_3280x2464_regs,
> +		},
> +	},
> +	{
> +		/* 1080P 30fps cropped */
> +		.width = 1920,
> +		.height = 1080,
> +		.vts_def = IMX219_VTS_30FPS_1080P,
> +		.reg_list = {
> +			.num_of_regs = ARRAY_SIZE(mode_1920_1080_regs),
> +			.regs = mode_1920_1080_regs,
> +		},
> +	},
> +	{
> +		/* 2x2 binned 30fps mode */
> +		.width = 1640,
> +		.height = 1232,
> +		.vts_def = IMX219_VTS_30FPS_BINNED,
> +		.reg_list = {
> +			.num_of_regs = ARRAY_SIZE(mode_1640_1232_regs),
> +			.regs = mode_1640_1232_regs,
> +		},
> +	},
> +};
> +
> +struct imx219 {
> +	struct device *dev;
> +
> +	struct v4l2_subdev sd;
> +	struct media_pad pad;
> +
> +	struct v4l2_fwnode_endpoint ep; /* the parsed DT endpoint info */
> +	struct clk *xclk; /* system clock to IMX219 */
> +	u32 xclk_freq;
> +
> +	struct gpio_desc *xclr_gpio;
> +	struct regulator_bulk_data supplies[IMX219_NUM_SUPPLIES];
> +
> +	struct v4l2_ctrl_handler ctrl_handler;
> +	/* V4L2 Controls */
> +	struct v4l2_ctrl *pixel_rate;
> +	struct v4l2_ctrl *exposure;
> +	struct v4l2_ctrl *vflip;
> +	struct v4l2_ctrl *hflip;
> +	struct v4l2_ctrl *vblank;
> +	struct v4l2_ctrl *hblank;
> +
> +	/* Current mode */
> +	const struct imx219_mode *mode;
> +
> +	/*
> +	 * Mutex for serialized access:
> +	 * Protect sensor module set pad format and start/stop streaming safely.
> +	 */
> +	struct mutex mutex;
> +
> +	/* Streaming on/off */
> +	bool streaming;
> +};
> +
> +static inline struct imx219 *to_imx219(struct v4l2_subdev *_sd)
> +{
> +	return container_of(_sd, struct imx219, sd);
> +}
> +
> +/* Read registers up to 2 at a time */
> +static int imx219_read_reg(struct imx219 *imx219, u16 reg, u32 len, u32 *val)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	struct i2c_msg msgs[2];
> +	u8 addr_buf[2] = { reg >> 8, reg & 0xff };
> +	u8 data_buf[4] = { 0, };
> +	int ret;
> +
> +	if (len > 4)
> +		return -EINVAL;
> +
> +	/* 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;
> +}
> +
> +/* Write registers up to 2 at a time */
> +static int imx219_write_reg(struct imx219 *imx219, u16 reg, u32 len, u32 val)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	u8 buf[6];
> +
> +	if (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;
> +}
> +
> +/* Write a list of registers */
> +static int imx219_write_regs(struct imx219 *imx219,
> +			     const struct imx219_reg *regs, u32 len)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	unsigned int i;
> +	int ret;
> +
> +	for (i = 0; i < len; i++) {
> +		ret = imx219_write_reg(imx219, regs[i].address, 1, regs[i].val);
> +		if (ret) {
> +			dev_err_ratelimited(&client->dev,
> +					    "Failed to write reg 0x%4.4x. error = %d\n",
> +					    regs[i].address, ret);
> +
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +/* Get bayer order based on flip setting. */
> +static u32 imx219_get_format_code(struct imx219 *imx219)
> +{
> +	/*
> +	 * Only one bayer order is supported.
> +	 * It depends on the flip settings.
> +	 */
> +	static const u32 codes[2][2] = {
> +		{ MEDIA_BUS_FMT_SRGGB10_1X10, MEDIA_BUS_FMT_SGRBG10_1X10, },
> +		{ MEDIA_BUS_FMT_SGBRG10_1X10, MEDIA_BUS_FMT_SBGGR10_1X10, },
> +	};
> +
> +	lockdep_assert_held(&imx219->mutex);
> +	return codes[imx219->vflip->val][imx219->hflip->val];
> +}
> +
> +static int imx219_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> +	struct imx219 *imx219 = to_imx219(sd);
> +	struct v4l2_mbus_framefmt *try_fmt =
> +		v4l2_subdev_get_try_format(sd, fh->pad, 0);
> +
> +	mutex_lock(&imx219->mutex);
> +
> +	/* Initialize try_fmt */
> +	try_fmt->width = supported_modes[0].width;
> +	try_fmt->height = supported_modes[0].height;
> +	try_fmt->code = imx219_get_format_code(imx219);

Please assign this when getting the format (subdev pad get_fmt callback).

> +	try_fmt->field = V4L2_FIELD_NONE;
> +
> +	mutex_unlock(&imx219->mutex);
> +
> +	return 0;
> +}
> +
> +static int imx219_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct imx219 *imx219 =
> +		container_of(ctrl->handler, struct imx219, ctrl_handler);
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	int ret;
> +
> +	if (ctrl->id == V4L2_CID_VBLANK) {
> +		int exposure_max, exposure_def;
> +
> +		/* Update max exposure while meeting expected vblanking */
> +		exposure_max = imx219->mode->height + ctrl->val - 4;
> +		exposure_def = (exposure_max < IMX219_EXPOSURE_DEFAULT) ?
> +			exposure_max : IMX219_EXPOSURE_DEFAULT;
> +		__v4l2_ctrl_modify_range(imx219->exposure,
> +					 imx219->exposure->minimum,
> +					 exposure_max, imx219->exposure->step,
> +					 exposure_def);
> +	}
> +
> +	/*
> +	 * Applying V4L2 control value only happens
> +	 * when power is up for streaming
> +	 */
> +	if (pm_runtime_get_if_in_use(&client->dev) == 0)
> +		return 0;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_ANALOGUE_GAIN:
> +		ret = imx219_write_reg(imx219, IMX219_REG_ANALOG_GAIN,
> +				       IMX219_REG_VALUE_08BIT, ctrl->val);
> +		break;
> +	case V4L2_CID_EXPOSURE:
> +		ret = imx219_write_reg(imx219, IMX219_REG_EXPOSURE,
> +				       IMX219_REG_VALUE_16BIT, ctrl->val);
> +		break;
> +	case V4L2_CID_DIGITAL_GAIN:
> +		ret = imx219_write_reg(imx219, IMX219_REG_DIGITAL_GAIN,
> +				       IMX219_REG_VALUE_16BIT, ctrl->val);
> +		break;
> +	case V4L2_CID_TEST_PATTERN:
> +		ret = imx219_write_reg(imx219, IMX219_REG_TEST_PATTERN,
> +				       IMX219_REG_VALUE_16BIT,
> +				       imx219_test_pattern_val[ctrl->val]);
> +		break;
> +	case V4L2_CID_HFLIP:
> +	case V4L2_CID_VFLIP:
> +		ret = imx219_write_reg(imx219, IMX219_REG_ORIENTATION, 1,
> +				       imx219->hflip->val |
> +				       imx219->vflip->val << 1);
> +		break;
> +	case V4L2_CID_VBLANK:
> +		ret = imx219_write_reg(imx219, IMX219_REG_VTS,
> +				       IMX219_REG_VALUE_16BIT,
> +				       imx219->mode->height + ctrl->val);
> +		break;
> +	case V4L2_CID_TEST_PATTERN_RED:
> +		ret = imx219_write_reg(imx219, IMX219_REG_TESTP_RED,
> +				       IMX219_REG_VALUE_16BIT, ctrl->val);
> +		break;
> +	case V4L2_CID_TEST_PATTERN_GREENR:
> +		ret = imx219_write_reg(imx219, IMX219_REG_TESTP_GREENR,
> +				       IMX219_REG_VALUE_16BIT, ctrl->val);
> +		break;
> +	case V4L2_CID_TEST_PATTERN_BLUE:
> +		ret = imx219_write_reg(imx219, IMX219_REG_TESTP_BLUE,
> +				       IMX219_REG_VALUE_16BIT, ctrl->val);
> +		break;
> +	case V4L2_CID_TEST_PATTERN_GREENB:
> +		ret = imx219_write_reg(imx219, IMX219_REG_TESTP_GREENB,
> +				       IMX219_REG_VALUE_16BIT, ctrl->val);
> +		break;
> +	default:
> +		dev_info(&client->dev,
> +			 "ctrl(id:0x%x,val:0x%x) is not handled\n",
> +			 ctrl->id, ctrl->val);
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	pm_runtime_put(&client->dev);
> +
> +	return ret;
> +}
> +
> +static const struct v4l2_ctrl_ops imx219_ctrl_ops = {
> +	.s_ctrl = imx219_set_ctrl,
> +};
> +
> +static int imx219_enum_mbus_code(struct v4l2_subdev *sd,
> +				 struct v4l2_subdev_pad_config *cfg,
> +				 struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	struct imx219 *imx219 = to_imx219(sd);
> +
> +	/*
> +	 * Only one bayer order is supported (though it depends on the flip
> +	 * settings)
> +	 */
> +	if (code->index > 0)
> +		return -EINVAL;
> +
> +	code->code = imx219_get_format_code(imx219);
> +
> +	return 0;
> +}
> +
> +static int imx219_enum_frame_size(struct v4l2_subdev *sd,
> +				  struct v4l2_subdev_pad_config *cfg,
> +				  struct v4l2_subdev_frame_size_enum *fse)
> +{
> +	struct imx219 *imx219 = to_imx219(sd);
> +
> +	if (fse->index >= ARRAY_SIZE(supported_modes))
> +		return -EINVAL;
> +
> +	if (fse->code != imx219_get_format_code(imx219))
> +		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 imx219_reset_colorspace(struct v4l2_mbus_framefmt *fmt)
> +{
> +	fmt->colorspace = V4L2_COLORSPACE_SRGB;
> +	fmt->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(fmt->colorspace);
> +	fmt->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true,
> +							  fmt->colorspace,
> +							  fmt->ycbcr_enc);
> +	fmt->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(fmt->colorspace);
> +}
> +
> +static void imx219_update_pad_format(struct imx219 *imx219,
> +				     const struct imx219_mode *mode,
> +				     struct v4l2_subdev_format *fmt)
> +{
> +	fmt->format.width = mode->width;
> +	fmt->format.height = mode->height;
> +	fmt->format.code = imx219_get_format_code(imx219);
> +	fmt->format.field = V4L2_FIELD_NONE;
> +
> +	imx219_reset_colorspace(&fmt->format);
> +}
> +
> +static int __imx219_get_pad_format(struct imx219 *imx219,
> +				   struct v4l2_subdev_pad_config *cfg,
> +				   struct v4l2_subdev_format *fmt)
> +{
> +	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> +		fmt->format = *v4l2_subdev_get_try_format(&imx219->sd, cfg,
> +							  fmt->pad);
> +	else
> +		imx219_update_pad_format(imx219, imx219->mode, fmt);
> +
> +	return 0;
> +}
> +
> +static int imx219_get_pad_format(struct v4l2_subdev *sd,
> +				 struct v4l2_subdev_pad_config *cfg,
> +				 struct v4l2_subdev_format *fmt)
> +{
> +	struct imx219 *imx219 = to_imx219(sd);
> +	int ret;
> +
> +	mutex_lock(&imx219->mutex);
> +	ret = __imx219_get_pad_format(imx219, cfg, fmt);
> +	mutex_unlock(&imx219->mutex);
> +
> +	return ret;
> +}
> +
> +static int imx219_set_pad_format(struct v4l2_subdev *sd,
> +				 struct v4l2_subdev_pad_config *cfg,
> +				 struct v4l2_subdev_format *fmt)
> +{
> +	struct imx219 *imx219 = to_imx219(sd);
> +	const struct imx219_mode *mode;
> +	struct v4l2_mbus_framefmt *framefmt;
> +	int exposure_max, exposure_def, hblank;
> +
> +	mutex_lock(&imx219->mutex);
> +
> +	/* Bayer order varies with flips */
> +	fmt->format.code = imx219_get_format_code(imx219);
> +
> +	mode = v4l2_find_nearest_size(supported_modes,
> +				      ARRAY_SIZE(supported_modes),
> +				      width, height,
> +				      fmt->format.width, fmt->format.height);
> +	imx219_update_pad_format(imx219, mode, fmt);
> +	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
> +		framefmt = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
> +		*framefmt = fmt->format;
> +	} else if (imx219->mode != mode) {
> +		imx219->mode = mode;
> +		/* Update limits and set FPS to default */
> +		__v4l2_ctrl_modify_range(imx219->vblank, IMX219_VBLANK_MIN,
> +					 IMX219_VTS_MAX - mode->height, 1,
> +					 mode->vts_def - mode->height);
> +		__v4l2_ctrl_s_ctrl(imx219->vblank,
> +				   mode->vts_def - mode->height);
> +		/* Update max exposure while meeting expected vblanking */
> +		exposure_max = mode->vts_def - 4;
> +		exposure_def = (exposure_max < IMX219_EXPOSURE_DEFAULT) ?
> +			exposure_max : IMX219_EXPOSURE_DEFAULT;
> +		__v4l2_ctrl_modify_range(imx219->exposure,
> +					 imx219->exposure->minimum,
> +					 exposure_max, imx219->exposure->step,
> +					 exposure_def);
> +		/*
> +		 * Currently PPL is fixed to IMX219_PPL_DEFAULT, so hblank
> +		 * depends on mode->width only, and is not changeble in any
> +		 * way other than changing the mode.
> +		 */
> +		hblank = IMX219_PPL_DEFAULT - mode->width;
> +		__v4l2_ctrl_modify_range(imx219->hblank, hblank, hblank, 1,
> +					 hblank);
> +	}
> +
> +	mutex_unlock(&imx219->mutex);
> +
> +	return 0;
> +}
> +
> +static int imx219_start_streaming(struct imx219 *imx219)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	const struct imx219_reg_list *reg_list;
> +	int ret;
> +
> +	/* Apply default values of current mode */
> +	reg_list = &imx219->mode->reg_list;
> +	ret = imx219_write_regs(imx219, reg_list->regs, reg_list->num_of_regs);
> +	if (ret) {
> +		dev_err(&client->dev, "%s failed to set mode\n", __func__);
> +		return ret;
> +	}
> +
> +	/* Apply customized values from user */
> +	ret =  __v4l2_ctrl_handler_setup(imx219->sd.ctrl_handler);
> +	if (ret)
> +		return ret;
> +
> +	/* set stream on register */
> +	return imx219_write_reg(imx219, IMX219_REG_MODE_SELECT,
> +				IMX219_REG_VALUE_08BIT, IMX219_MODE_STREAMING);
> +}
> +
> +static void imx219_stop_streaming(struct imx219 *imx219)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	int ret;
> +
> +	/* set stream off register */
> +	ret = imx219_write_reg(imx219, IMX219_REG_MODE_SELECT,
> +			       IMX219_REG_VALUE_08BIT, IMX219_MODE_STANDBY);
> +	if (ret)
> +		dev_err(&client->dev, "%s failed to set stream\n", __func__);
> +}
> +
> +static int imx219_set_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct imx219 *imx219 = to_imx219(sd);
> +	struct i2c_client *client = v4l2_get_subdevdata(sd);
> +	int ret = 0;
> +
> +	mutex_lock(&imx219->mutex);
> +	if (imx219->streaming == enable) {
> +		mutex_unlock(&imx219->mutex);
> +		return 0;
> +	}
> +
> +	if (enable) {
> +		ret = pm_runtime_get_sync(&client->dev);
> +		if (ret < 0) {
> +			pm_runtime_put_noidle(&client->dev);
> +			goto err_unlock;
> +		}
> +
> +		/*
> +		 * Apply default & customized values
> +		 * and then start streaming.
> +		 */
> +		ret = imx219_start_streaming(imx219);
> +		if (ret)
> +			goto err_rpm_put;
> +	} else {
> +		imx219_stop_streaming(imx219);
> +		pm_runtime_put(&client->dev);
> +	}
> +
> +	imx219->streaming = enable;
> +
> +	/* vflip and hflip cannot change during streaming */
> +	__v4l2_ctrl_grab(imx219->vflip, enable);
> +	__v4l2_ctrl_grab(imx219->hflip, enable);
> +
> +	mutex_unlock(&imx219->mutex);
> +
> +	return ret;
> +
> +err_rpm_put:
> +	pm_runtime_put(&client->dev);
> +err_unlock:
> +	mutex_unlock(&imx219->mutex);
> +
> +	return ret;
> +}
> +
> +/* Power/clock management functions */
> +static int imx219_power_on(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct imx219 *imx219 = to_imx219(sd);
> +	int ret;
> +
> +	ret = regulator_bulk_enable(IMX219_NUM_SUPPLIES,
> +				    imx219->supplies);
> +	if (ret) {
> +		dev_err(&client->dev, "%s: failed to enable regulators\n",
> +			__func__);
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(imx219->xclk);
> +	if (ret) {
> +		dev_err(&client->dev, "%s: failed to enable clock\n",
> +			__func__);
> +		goto reg_off;
> +	}
> +
> +	gpiod_set_value_cansleep(imx219->xclr_gpio, 1);
> +	msleep(IMX219_XCLR_DELAY_MS);

I guess 10 ms is ok albeit it'd be nicer if you calculated the required
delay instead.

> +
> +	return 0;

Empty line here, please.

> +reg_off:
> +	regulator_bulk_disable(IMX219_NUM_SUPPLIES, imx219->supplies);

And here.

> +	return ret;
> +}
> +
> +static int imx219_power_off(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct imx219 *imx219 = to_imx219(sd);
> +
> +	gpiod_set_value_cansleep(imx219->xclr_gpio, 0);
> +	regulator_bulk_disable(IMX219_NUM_SUPPLIES, imx219->supplies);
> +	clk_disable_unprepare(imx219->xclk);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused imx219_suspend(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct imx219 *imx219 = to_imx219(sd);
> +
> +	if (imx219->streaming)
> +		imx219_stop_streaming(imx219);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused imx219_resume(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct imx219 *imx219 = to_imx219(sd);
> +	int ret;
> +
> +	if (imx219->streaming) {
> +		ret = imx219_start_streaming(imx219);
> +		if (ret)
> +			goto error;
> +	}
> +
> +	return 0;
> +
> +error:
> +	imx219_stop_streaming(imx219);
> +	imx219->streaming = 0;

Please add an empty line here.

> +	return ret;
> +}
> +
> +static int imx219_get_regulators(struct imx219 *imx219)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	int i;

unsigned int

> +
> +	for (i = 0; i < IMX219_NUM_SUPPLIES; i++)
> +		imx219->supplies[i].supply = imx219_supply_name[i];
> +
> +	return devm_regulator_bulk_get(&client->dev,
> +				       IMX219_NUM_SUPPLIES,
> +				       imx219->supplies);
> +}
> +
> +/* Verify chip ID */
> +static int imx219_identify_module(struct imx219 *imx219)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	int ret;
> +	u32 val;
> +
> +	ret = imx219_read_reg(imx219, IMX219_REG_CHIP_ID,
> +			      IMX219_REG_VALUE_16BIT, &val);
> +	if (ret) {
> +		dev_err(&client->dev, "failed to read chip id %x\n",
> +			IMX219_CHIP_ID);
> +		return ret;
> +	}
> +
> +	if (val != IMX219_CHIP_ID) {
> +		dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
> +			IMX219_CHIP_ID, val);
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_core_ops imx219_core_ops = {
> +	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
> +	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
> +};
> +
> +static const struct v4l2_subdev_video_ops imx219_video_ops = {
> +	.s_stream = imx219_set_stream,
> +};
> +
> +static const struct v4l2_subdev_pad_ops imx219_pad_ops = {
> +	.enum_mbus_code = imx219_enum_mbus_code,
> +	.get_fmt = imx219_get_pad_format,
> +	.set_fmt = imx219_set_pad_format,
> +	.enum_frame_size = imx219_enum_frame_size,
> +};
> +
> +static const struct v4l2_subdev_ops imx219_subdev_ops = {
> +	.core = &imx219_core_ops,
> +	.video = &imx219_video_ops,
> +	.pad = &imx219_pad_ops,
> +};
> +
> +static const struct v4l2_subdev_internal_ops imx219_internal_ops = {
> +	.open = imx219_open,
> +};
> +
> +/* Initialize control handlers */
> +static int imx219_init_controls(struct imx219 *imx219)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
> +	struct v4l2_ctrl_handler *ctrl_hdlr;
> +	unsigned int height = imx219->mode->height;
> +	int exposure_max, exposure_def, hblank;
> +	int i, ret;
> +
> +	ctrl_hdlr = &imx219->ctrl_handler;
> +	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 9);
> +	if (ret)
> +		return ret;
> +
> +	mutex_init(&imx219->mutex);
> +	ctrl_hdlr->lock = &imx219->mutex;
> +
> +	/* By default, PIXEL_RATE is read only */
> +	imx219->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
> +					       V4L2_CID_PIXEL_RATE,
> +					       IMX219_PIXEL_RATE,
> +					       IMX219_PIXEL_RATE, 1,
> +					       IMX219_PIXEL_RATE);
> +
> +	/* Initial vblank/hblank/exposure parameters based on current mode */
> +	imx219->vblank = v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
> +					   V4L2_CID_VBLANK, IMX219_VBLANK_MIN,
> +					   IMX219_VTS_MAX - height, 1,
> +					   imx219->mode->vts_def - height);
> +	hblank = IMX219_PPL_DEFAULT - imx219->mode->width;
> +	imx219->hblank = v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
> +					   V4L2_CID_HBLANK, hblank, hblank,
> +					   1, hblank);
> +	if (imx219->hblank)
> +		imx219->hblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +	exposure_max = imx219->mode->vts_def - 4;
> +	exposure_def = (exposure_max < IMX219_EXPOSURE_DEFAULT) ?
> +		exposure_max : IMX219_EXPOSURE_DEFAULT;
> +	imx219->exposure = v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
> +					     V4L2_CID_EXPOSURE,
> +					     IMX219_EXPOSURE_MIN, exposure_max,
> +					     IMX219_EXPOSURE_STEP,
> +					     exposure_def);
> +
> +	v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops, V4L2_CID_ANALOGUE_GAIN,
> +			  IMX219_ANA_GAIN_MIN, IMX219_ANA_GAIN_MAX,
> +			  IMX219_ANA_GAIN_STEP, IMX219_ANA_GAIN_DEFAULT);
> +
> +	v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops, V4L2_CID_DIGITAL_GAIN,
> +			  IMX219_DGTL_GAIN_MIN, IMX219_DGTL_GAIN_MAX,
> +			  IMX219_DGTL_GAIN_STEP, IMX219_DGTL_GAIN_DEFAULT);
> +
> +	imx219->hflip = v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
> +					  V4L2_CID_HFLIP, 0, 1, 1, 0);
> +	if (imx219->hflip)
> +		imx219->hflip->flags |= V4L2_CTRL_FLAG_MODIFY_LAYOUT;
> +
> +	imx219->vflip = v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
> +					  V4L2_CID_VFLIP, 0, 1, 1, 0);
> +	if (imx219->vflip)
> +		imx219->vflip->flags |= V4L2_CTRL_FLAG_MODIFY_LAYOUT;
> +
> +	v4l2_ctrl_new_std_menu_items(ctrl_hdlr, &imx219_ctrl_ops,
> +				     V4L2_CID_TEST_PATTERN,
> +				     ARRAY_SIZE(imx219_test_pattern_menu) - 1,
> +				     0, 0, imx219_test_pattern_menu);
> +	for (i = 0; i < 4; i++) {
> +		/*
> +		 * The assumption is that
> +		 * V4L2_CID_TEST_PATTERN_GREENR == V4L2_CID_TEST_PATTERN_RED + 1
> +		 * V4L2_CID_TEST_PATTERN_BLUE   == V4L2_CID_TEST_PATTERN_RED + 2
> +		 * V4L2_CID_TEST_PATTERN_GREENB == V4L2_CID_TEST_PATTERN_RED + 3
> +		 */
> +		v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
> +				  V4L2_CID_TEST_PATTERN_RED + i,
> +				  IMX219_TESTP_COLOUR_MIN,
> +				  IMX219_TESTP_COLOUR_MAX,
> +				  IMX219_TESTP_COLOUR_STEP,
> +				  IMX219_TESTP_COLOUR_MAX);
> +		/* The "Solid color" pattern is white by default */
> +	}
> +
> +	if (ctrl_hdlr->error) {
> +		ret = ctrl_hdlr->error;
> +		dev_err(&client->dev, "%s control init failed (%d)\n",
> +			__func__, ret);
> +		goto error;
> +	}
> +
> +	imx219->sd.ctrl_handler = ctrl_hdlr;
> +
> +	return 0;
> +
> +error:
> +	v4l2_ctrl_handler_free(ctrl_hdlr);
> +	mutex_destroy(&imx219->mutex);
> +
> +	return ret;
> +}
> +
> +static void imx219_free_controls(struct imx219 *imx219)
> +{
> +	v4l2_ctrl_handler_free(imx219->sd.ctrl_handler);
> +	mutex_destroy(&imx219->mutex);
> +}
> +
> +static int imx219_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	struct fwnode_handle *endpoint;
> +	struct imx219 *imx219;
> +	int ret;
> +
> +	imx219 = devm_kzalloc(&client->dev, sizeof(*imx219), GFP_KERNEL);
> +	if (!imx219)
> +		return -ENOMEM;
> +
> +	imx219->dev = dev;

Instead of putting a dev field to struct imx219, you can find the device in
struct i2c_client.dev, which you can get by:

	v4l2_get_subdevdata(imx219->sd)

> +
> +	v4l2_i2c_subdev_init(&imx219->sd, client, &imx219_subdev_ops);
> +
> +	/* Get CSI2 bus config */
> +	endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev),
> +						  NULL);
> +	if (!endpoint) {
> +		dev_err(dev, "endpoint node not found\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = v4l2_fwnode_endpoint_parse(endpoint, &imx219->ep);
> +	fwnode_handle_put(endpoint);
> +	if (ret) {
> +		dev_err(dev, "Could not parse endpoint\n");
> +		return ret;
> +	}
> +
> +	/* Get system clock (xclk) */
> +	imx219->xclk = devm_clk_get(dev, "xclk");
> +	if (IS_ERR(imx219->xclk)) {
> +		dev_err(dev, "failed to get xclk\n");
> +		return PTR_ERR(imx219->xclk);
> +	}
> +
> +	imx219->xclk_freq = clk_get_rate(imx219->xclk);
> +	if (imx219->xclk_freq != IMX219_XCLK_FREQ) {
> +		dev_err(dev, "xclk frequency not supported: %d Hz\n",
> +			imx219->xclk_freq);
> +		return -EINVAL;
> +	}

Could you also check the link frequencies (the link-frequencies property
that also should be added to DT bindings) matches with what is possible
with the given xclk frequency? Please see e.g. imx319 driver for an
example.

> +
> +	ret = imx219_get_regulators(imx219);
> +	if (ret)
> +		return ret;
> +
> +	/* Request optional enable pin */
> +	imx219->xclr_gpio = devm_gpiod_get_optional(dev, "xclr",
> +						    GPIOD_OUT_HIGH);
> +
> +	/*
> +	 * The sensor must be powered for imx219_identify_module()
> +	 * to be able to read the CHIP_ID register
> +	 */
> +	ret = imx219_power_on(dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = imx219_identify_module(imx219);
> +	if (ret)
> +		goto error_power_off;
> +
> +	/* Set default mode to max resolution */
> +	imx219->mode = &supported_modes[0];
> +
> +	ret = imx219_init_controls(imx219);
> +	if (ret)
> +		goto error_power_off;
> +
> +	/* Initialize subdev */
> +	imx219->sd.internal_ops = &imx219_internal_ops;
> +	imx219->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	imx219->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> +
> +	/* Initialize source pad */
> +	imx219->pad.flags = MEDIA_PAD_FL_SOURCE;
> +
> +	ret = media_entity_pads_init(&imx219->sd.entity, 1, &imx219->pad);
> +	if (ret)
> +		goto error_handler_free;
> +
> +	ret = v4l2_async_register_subdev_sensor_common(&imx219->sd);
> +	if (ret < 0)
> +		goto error_media_entity;
> +
> +	/* Enable runtime PM and turn off the device */
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +	pm_runtime_idle(dev);
> +
> +	return 0;
> +
> +error_media_entity:
> +	media_entity_cleanup(&imx219->sd.entity);
> +
> +error_handler_free:
> +	imx219_free_controls(imx219);
> +
> +error_power_off:
> +	imx219_power_off(dev);
> +
> +	return ret;
> +}
> +
> +static int imx219_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct imx219 *imx219 = to_imx219(sd);
> +
> +	v4l2_async_unregister_subdev(sd);
> +	media_entity_cleanup(&sd->entity);
> +	imx219_free_controls(imx219);
> +
> +	pm_runtime_disable(&client->dev);
> +	pm_runtime_set_suspended(&client->dev);

imx219_power_off(), if the sensor is powered on here. Please see e.g. the
smiapp driver regarding this.

> +
> +	return 0;
> +}
> +
> +static const struct of_device_id imx219_dt_ids[] = {
> +	{ .compatible = "sony,imx219" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, imx219_dt_ids);
> +
> +static const struct dev_pm_ops imx219_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(imx219_suspend, imx219_resume)
> +	SET_RUNTIME_PM_OPS(imx219_power_off, imx219_power_on, NULL)
> +};
> +
> +static struct i2c_driver imx219_i2c_driver = {
> +	.driver = {
> +		.name = "imx219",
> +		.of_match_table	= imx219_dt_ids,
> +		.pm = &imx219_pm_ops,
> +	},
> +	.probe = imx219_probe,

Could you use .probe_new, and remove the i2c_device_id argument?

> +	.remove = imx219_remove,
> +};
> +
> +module_i2c_driver(imx219_i2c_driver);
> +
> +MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.com");
> +MODULE_DESCRIPTION("Sony IMX219 sensor driver");
> +MODULE_LICENSE("GPL v2");

-- 
Regards,

Sakari Ailus