RE: [PATCH 2/2] media: Add imx334 camera sensor driver

[<martinax.krasteva@linux.intel.com>]

Hi Andrey, Jacopo,

Thank you for your time

> -----Original Message-----
> From: Andrey Konovalov <andrey.konovalov@linaro.org>
> Sent: Monday, November 23, 2020 11:36 AM
> To: Jacopo Mondi <jacopo@jmondi.org>; Martina Krasteva
> <martinax.krasteva@linux.intel.com>
> Cc: linux-media@vger.kernel.org; mchehab@kernel.org; robh+dt@kernel.org;
> devicetree@vger.kernel.org; sakari.ailus@linux.intel.com;
> daniele.alessandrelli@linux.intel.com; gjorgjix.rosikopulos@linux.intel.com
> Subject: Re: [PATCH 2/2] media: Add imx334 camera sensor driver
> 
> Hi,
> 
> Martina, thanks for the patch
> 
> Jacopo, thanks for the review
> 
> One minor comment below..
> 
> On 23.11.2020 14:10, Jacopo Mondi wrote:
> > Hi Martina,
> >     thanks, a few comments below quickly skimming through the driver
> >
> > On Fri, Nov 20, 2020 at 02:28:03PM +0000, Martina Krasteva wrote:
> >> From: Martina Krasteva <martinax.krasteva@intel.com>
> >>
> >> Add a v4l2 sub-device driver for the Sony imx334 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 control support
> >> - supported resolution:
> >>      - 3840x2160 @ 60fps
> >> - supported bayer order output:
> >>      - SRGGB12
> >>
> >> Signed-off-by: Martina Krasteva <martinax.krasteva@intel.com>
> >> Reviewed-by: Gjorgji Rosikopulos <gjorgjix.rosikopulos@intel.com>
> >> Acked-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
> >> ---
> >>   MAINTAINERS                |    1 +
> >>   drivers/media/i2c/Kconfig  |   14 +
> >>   drivers/media/i2c/Makefile |    1 +
> >>   drivers/media/i2c/imx334.c | 1089
> ++++++++++++++++++++++++++++++++++++++++++++
> >>   4 files changed, 1105 insertions(+)
> >>   create mode 100644 drivers/media/i2c/imx334.c
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS index
> >> 6cfce99be4bb..24438c53861b 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -16326,6 +16326,7 @@ L:	linux-media@vger.kernel.org
> >>   S:	Maintained
> >>   T:	git git://linuxtv.org/media_tree.git
> >>   F:	Documentation/devicetree/bindings/media/i2c/sony,imx334.yaml
> >> +F:	drivers/media/i2c/imx334.c
> >>
> >>   SONY IMX355 SENSOR DRIVER
> >>   M:	Tianshu Qiu <tian.shu.qiu@intel.com>
> >> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> >> index 878f66ef2719..f67b7e05b796 100644
> >> --- a/drivers/media/i2c/Kconfig
> >> +++ b/drivers/media/i2c/Kconfig
> >> @@ -813,6 +813,20 @@ config VIDEO_IMX319
> >>   	  To compile this driver as a module, choose M here: the
> >>   	  module will be called imx319.
> >>
> >> +config VIDEO_IMX334
> >> +	tristate "Sony IMX334 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
> >> +	  IMX334 camera.
> >> +
> >> +	  To compile this driver as a module, choose M here: the
> >> +	  module will be called imx334.
> >> +
> >>   config VIDEO_IMX355
> >>   	tristate "Sony IMX355 sensor support"
> >>   	depends on I2C && VIDEO_V4L2
> >> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> >> index f0a77473979d..aeaeaab3783c 100644
> >> --- a/drivers/media/i2c/Makefile
> >> +++ b/drivers/media/i2c/Makefile
> >> @@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_IMX258)	+= imx258.o
> >>   obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
> >>   obj-$(CONFIG_VIDEO_IMX290)	+= imx290.o
> >>   obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
> >> +obj-$(CONFIG_VIDEO_IMX334)	+= imx334.o
> >>   obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
> >>   obj-$(CONFIG_VIDEO_MAX9286)	+= max9286.o
> >>   rdacm20-camera_module-objs	:= rdacm20.o max9271.o
> >> diff --git a/drivers/media/i2c/imx334.c b/drivers/media/i2c/imx334.c
> >> new file mode 100644 index 000000000000..8fd2c1c934fd
> >> --- /dev/null
> >> +++ b/drivers/media/i2c/imx334.c
> >> @@ -0,0 +1,1089 @@
> >> +// SPDX-License-Identifier: GPL-2.0-only
> >> +/*
> >> + * Sony imx334 sensor driver
> >> + *
> >> + * Copyright (C) 2019-2020 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 <linux/platform_device.h>
> >
> > Do you need this include ?

Oops, I don’t. I will double check all the includes
> >
> > I think you also need:
> >
> > #include <linux/gpio/consumer.h>
> > #include <linux/of.h>
> >
> >> +
> >> +#include <media/v4l2-ctrls.h>
> >> +#include <media/v4l2-device.h>
> >
> > I would replace v4l2-device.h with v4l2-subdev.h being this
> > effectively a subdev driver
> >
> >> +#include <media/v4l2-fwnode.h>
> >
> > You only use v4l2_async_register_subdev_sensor_common() from fwnde.h
> > If you think you can replace it with v4l2_async_register_subdev() (see
> > below comment) this should be changed in v4l2-async.h
> >
> >> +
> >> +#define IMX334_DRV_NAME		"imx334"
> >
> > Used in a single place, not sure it's worth it.
> >
> >> +
> >> +/* Streaming Mode */
> >> +#define IMX334_REG_MODE_SELECT	0x3000
> >> +#define IMX334_MODE_STANDBY	0x01
> >> +#define IMX334_MODE_STREAMING	0x00
> >> +
> >> +/* Lines per frame */
> >> +#define IMX334_REG_LPFR		0x3030
> >> +
> >> +#define IMX334_LPFR_MIN		0x08ca
> >> +#define IMX334_LPFR_MAX		0x20f58
> >> +
> >> +/* Chip ID */
> >> +#define IMX334_REG_ID		0x3044
> >> +#define IMX334_ID		0x1e00
> >> +
> >> +/* Exposure control */
> >> +#define IMX334_REG_SHUTTER	0x3058
> >> +#define IMX334_EXPOSURE_MIN	1
> >> +#define IMX334_EXPOSURE_OFFSET	5
> >> +#define IMX334_EXPOSURE_STEP	1
> >> +#define IMX334_EXPOSURE_DEFAULT	0x0648
> >> +
> >> +/* Analog gain control */
> >> +#define IMX334_REG_AGAIN	0x30e8
> >> +#define IMX334_AGAIN_MIN	0
> >> +#define IMX334_AGAIN_MAX	240
> >> +#define IMX334_AGAIN_STEP	1
> >> +#define IMX334_AGAIN_DEFAULT	0
> >> +
> >> +/* Group hold register */
> >> +#define IMX334_REG_HOLD		0x3001
> >> +
> >> +/* Input clock rate */
> >> +#define IMX334_INCLK_RATE	24000000
> >> +
> >> +#define IMX334_REG_MIN		0x00
> >> +#define IMX334_REG_MAX		0xfffff
> >> +
> >> +/**
> >> + * struct imx334_reg - imx334 sensor register
> >> + * @address: Register address
> >> + * @val: Register value
> >> + */
> >> +struct imx334_reg {
> >> +	u16 address;
> >> +	u8 val;
> >> +};
> >> +
> >> +/**
> >> + * struct imx334_reg_list - imx334 sensor register list
> >> + * @num_of_regs: Number of registers in the list
> >> + * @regs: Pointer to register list
> >> + */
> >> +struct imx334_reg_list {
> >> +	u32 num_of_regs;
> >> +	const struct imx334_reg *regs;
> >> +};
> >> +
> >> +/**
> >> + * struct imx334_mode - imx334 sensor mode structure
> >> + * @width: Frame width
> >> + * @height: Frame height
> >> + * @code: Format code
> >> + * @ppln: Pixels per line
> >> + * @lpfr: Lines per frame
> >> + * @pclk: Sensor pixel clock
> >> + * @reg_list: Register list for sensor mode  */ struct imx334_mode {
> >> +	u32 width;
> >> +	u32 height;
> >> +	u32 code;
> >> +	u32 ppln;
> >> +	u32 lpfr;
> >> +	u64 pclk;
> >> +	struct imx334_reg_list reg_list;
> >> +};
> >> +
> >> +/**
> >> + * struct imx334 - imx334 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
> >> + * @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
> >> + * @exp1_ctrl: Pointer to short exposure control
> >> + * @again1_ctrl: Pointer to short analog gain control
> >> + * @exp2_ctrl: Pointer to very short exposure control
> >> + * @again2_ctrl: Pointer to very short analog gain control
> >> + * @lpfr: Lines per frame for long exposure frame
> >> + * @cur_mode: Pointer to current selected sensor mode
> >> + * @mutex: Mutex for serializing sensor controls
> >> + * @streaming: Flag indicating streaming state
> >> + */
> >> +struct imx334 {
> >> +	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 *pclk_ctrl;
> >> +	struct v4l2_ctrl *hblank_ctrl;
> >> +	struct v4l2_ctrl *vblank_ctrl;
> >> +	struct {
> >> +		struct v4l2_ctrl *exp_ctrl;
> >> +		struct v4l2_ctrl *again_ctrl;
> >> +	};
> >> +	u32 lpfr;
> >
> > Can't you get lpfr from the current mode you have a pointer to here
> > below ?
I do use it when the user updates the VBLANK to set different frame rate.
> >
> >> +	const struct imx334_mode *cur_mode;
> >> +	struct mutex mutex;
> >
> > Checkpatch wants this mutex commented, but you have documentation so I
> > think it's fine
> >
> >> +	bool streaming;
> >> +};
> >> +
> >> +/* Sensor mode registers */
> >> +static const struct imx334_reg mode_3840x2160_regs[] = {
> >> +	{0x3000, 0x01},
> >> +	{0x3002, 0x00},
> >> +	{0x3018, 0x04},
> >> +	{0x37b0, 0x36},
> >> +	{0x304c, 0x00},
> >> +	{0x300c, 0x3b},
> >> +	{0x300d, 0x2a},
> >> +	{0x3034, 0x26},
> >> +	{0x3035, 0x02},
> >> +	{0x314c, 0x29},
> >> +	{0x314d, 0x01},
> >> +	{0x315a, 0x02},
> >> +	{0x3168, 0xa0},
> >> +	{0x316a, 0x7e},
> >> +	{0x3288, 0x21},
> >> +	{0x328a, 0x02},
> >> +	{0x302c, 0x3c},
> >> +	{0x302e, 0x00},
> >> +	{0x302f, 0x0f},
> >> +	{0x3076, 0x70},
> >> +	{0x3077, 0x08},
> >> +	{0x3090, 0x70},
> >> +	{0x3091, 0x08},
> >> +	{0x30d8, 0x20},
> >> +	{0x30d9, 0x12},
> >> +	{0x3308, 0x70},
> >> +	{0x3309, 0x08},
> >> +	{0x3414, 0x05},
> >> +	{0x3416, 0x18},
> >> +	{0x35ac, 0x0e},
> >> +	{0x3648, 0x01},
> >> +	{0x364a, 0x04},
> >> +	{0x364c, 0x04},
> >> +	{0x3678, 0x01},
> >> +	{0x367c, 0x31},
> >> +	{0x367e, 0x31},
> >> +	{0x3708, 0x02},
> >> +	{0x3714, 0x01},
> >> +	{0x3715, 0x02},
> >> +	{0x3716, 0x02},
> >> +	{0x3717, 0x02},
> >> +	{0x371c, 0x3d},
> >> +	{0x371d, 0x3f},
> >> +	{0x372c, 0x00},
> >> +	{0x372d, 0x00},
> >> +	{0x372e, 0x46},
> >> +	{0x372f, 0x00},
> >> +	{0x3730, 0x89},
> >> +	{0x3731, 0x00},
> >> +	{0x3732, 0x08},
> >> +	{0x3733, 0x01},
> >> +	{0x3734, 0xfe},
> >> +	{0x3735, 0x05},
> >> +	{0x375d, 0x00},
> >> +	{0x375e, 0x00},
> >> +	{0x375f, 0x61},
> >> +	{0x3760, 0x06},
> >> +	{0x3768, 0x1b},
> >> +	{0x3769, 0x1b},
> >> +	{0x376a, 0x1a},
> >> +	{0x376b, 0x19},
> >> +	{0x376c, 0x18},
> >> +	{0x376d, 0x14},
> >> +	{0x376e, 0x0f},
> >> +	{0x3776, 0x00},
> >> +	{0x3777, 0x00},
> >> +	{0x3778, 0x46},
> >> +	{0x3779, 0x00},
> >> +	{0x377a, 0x08},
> >> +	{0x377b, 0x01},
> >> +	{0x377c, 0x45},
> >> +	{0x377d, 0x01},
> >> +	{0x377e, 0x23},
> >> +	{0x377f, 0x02},
> >> +	{0x3780, 0xd9},
> >> +	{0x3781, 0x03},
> >> +	{0x3782, 0xf5},
> >> +	{0x3783, 0x06},
> >> +	{0x3784, 0xa5},
> >> +	{0x3788, 0x0f},
> >> +	{0x378a, 0xd9},
> >> +	{0x378b, 0x03},
> >> +	{0x378c, 0xeb},
> >> +	{0x378d, 0x05},
> >> +	{0x378e, 0x87},
> >> +	{0x378f, 0x06},
> >> +	{0x3790, 0xf5},
> >> +	{0x3792, 0x43},
> >> +	{0x3794, 0x7a},
> >> +	{0x3796, 0xa1},
> >> +	{0x3e04, 0x0e},
> >> +	{0x3a00, 0x01},
> >> +};
> >> +
> >> +/* Supported sensor mode configurations */
> >> +static const struct imx334_mode supported_mode = {
> >> +	.width = 3840,
> >> +	.height = 2160,
> >> +	.ppln = 4400,
> >> +	.lpfr = 4500,
> >> +	.pclk = 594000000,
> >> +	.code = MEDIA_BUS_FMT_SRGGB12_1X12,
> >> +	.reg_list = {
> >> +		.num_of_regs = ARRAY_SIZE(mode_3840x2160_regs),
> >> +		.regs = mode_3840x2160_regs,
> >> +	},
> >> +};
> >> +
> >> +/**
> >> + * to_imx334() - imv334 V4L2 sub-device to imx334 device.
> >> + * @subdev: pointer to imx334 V4L2 sub-device
> >> + *
> >> + * Return: Pointer to imx334 device
> >> + */
> >> +static inline struct imx334 *to_imx334(struct v4l2_subdev *subdev)
> >> +{
> >> +	return container_of(subdev, struct imx334, sd);
> >> +}
> >> +
> >> +/**
> >> + * imx334_read_reg() - Read registers.
> >> + * @imx334: pointer to imx334 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 imx334_read_reg(struct imx334 *imx334, u16 reg, u32 len, u32
> *val)
> >> +{
> >> +	struct i2c_client *client = v4l2_get_subdevdata(&imx334->sd);
> >> +	u8 addr_buf[2] = { reg >> 8, reg & 0xff };
> >> +	struct i2c_msg msgs[2] = { 0 };
> >> +	u8 data_buf[4] = { 0 };
> >> +	int ret;
> >> +
> >> +	if (WARN_ON(len > 4))
> >> +		return -EINVAL;
> >
> > This function (and the associated write_reg) are for internal use
> > only. This mean the only one that can get 'len' wrong is this driver
> > itself. Is it worth checking for that ?
> >
> >> +
> >> +	/* 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;
> >> +}
> >> +
> >> +/**
> >> + * imx334_write_reg() - Write register
> >> + * @imx334: pointer to imx334 device
> >
> > writing kernel doc for functions with internal use only is sometimes
> > an effort which is nice to do but not required. If you want to go that
> > way try to stay consisitent, in this case you started the other
> > parameters descriptions with a capital letter.
> >
> > Also if you want kernel doc to be generated I think you would need to
> > include this file in the Documentation build, otherwise doc does not
> > get build as far as I can tell. To be hones I would drop the double **
> > and make this regular documentation (I'm no expert on this, maybe wait
> > for maintainer's feedback).
> >

I will fix the comments so they are consistent

> >> + * @reg: Register address
> >> + * @len: Length of bytes. Max supported bytes is 4
> >> + * @val: Register value
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_write_reg(struct imx334 *imx334, u16 reg, u32 len, u32
> val)
> >> +{
> >> +	struct i2c_client *client = v4l2_get_subdevdata(&imx334->sd);
> >> +	u8 buf[3] = {0};
> >> +	int ret;
> >> +	int i;
> >> +
> >> +	if (WARN_ON(len > 4))
> >> +		return -EINVAL;
> >> +
> >> +	/* Currently we can write to sensor only one byte at a time */
> >
> > How so ?

I don't think this is true. I need to double check.

> >
> >> +	for (i = 0; i < len; i++) {
> >> +		put_unaligned_be16(reg + i, buf);
> >> +		buf[2] = (val >> (8 * i)) & 0xff;
> >> +		ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
> >> +		if (ret != ARRAY_SIZE(buf)) {
> >> +			dev_err_ratelimited(imx334->dev,
> >> +					    "write reg 0x%4.4x return err %d",
> >> +					    reg, ret);
> >> +			return -EIO;
> >> +		}
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * imx334_write_regs() - Write a list of registers
> >> + * @imx334: pointer to imx334 device
> >> + * @regs: List of registers to be written
> >> + * @len: Length of registers array
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_write_regs(struct imx334 *imx334,
> >> +			     const struct imx334_reg *regs, u32 len)
> >> +{
> >> +	int ret;
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < len; i++) {
> >> +		ret = imx334_write_reg(imx334, regs[i].address, 1, regs[i].val);
> >> +		if (ret)
> >> +			return ret;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * imx334_update_controls() - Update control ranges based on streaming
> mode
> >> + * @imx334: pointer to imx334 device
> >> + * @mode: pointer to imx334_mode sensor mode
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_update_controls(struct imx334 *imx334,
> >> +				  const struct imx334_mode *mode)
> >> +{
> >> +	int ret;
> >> +
> >> +	ret = __v4l2_ctrl_s_ctrl(imx334->vblank_ctrl,
> >> +				 imx334->lpfr - mode->height);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	ret = __v4l2_ctrl_s_ctrl(imx334->hblank_ctrl, mode->ppln - mode-
> >width);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	ret = __v4l2_ctrl_modify_range(imx334->pclk_ctrl, mode->pclk,
> >> +				       mode->pclk, 1, mode->pclk);
> >> +	if (ret)
> >> +		return ret;
> >
> > Does pclk change, as you support a single mode and a single format ?
> >
I need to remove that

> >> +
> >> +	ret = __v4l2_ctrl_modify_range(imx334->exp_ctrl,
> IMX334_EXPOSURE_MIN,
> >> +				       imx334->lpfr - IMX334_EXPOSURE_OFFSET,
> >> +				       1, IMX334_EXPOSURE_DEFAULT);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/**
> >> + * imx334_update_exp_gain() - Set updated exposure and gain
> >> + * @imx334: pointer to imx334 device
> >> + * @exposure: updated exposure value
> >> + * @gain: updated analog gain value
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_update_exp_gain(struct imx334 *imx334, u32 exposure,
> u32 gain)
> >> +{
> >> +	u32 shutter = 0;
> >
> > No need for '= 0', it is immediately assigned below.
> >
> >> +	int ret;
> >> +
> >> +	shutter = imx334->lpfr - exposure;
> >> +
> >> +	dev_dbg(imx334->dev, "Set long exp %u analog gain %u sh0 %u lpfr
> %u",
> >> +		exposure, gain, shutter, imx334->lpfr);
> >> +
> >> +	ret = imx334_write_reg(imx334, IMX334_REG_HOLD, 1, 1);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	ret = imx334_write_reg(imx334, IMX334_REG_LPFR, 3, imx334->lpfr);
> >> +	if (ret)
> >> +		goto error_release_group_hold;
> >> +
> >> +	ret = imx334_write_reg(imx334, IMX334_REG_SHUTTER, 3, shutter);
> >> +	if (ret)
> >> +		goto error_release_group_hold;
> >> +
> >> +	ret = imx334_write_reg(imx334, IMX334_REG_AGAIN, 1, gain);
> 
> These lines can be dropped:
> -----8<-----
> >> +	if (ret)
> >> +		goto error_release_group_hold;
> >> +
> >> +	imx334_write_reg(imx334, IMX334_REG_HOLD, 1, 0);
> >> +
> >> +	return 0;
> >> +
> -----8<-----
> - as when (ret == 0) the below code works the same as the above two lines
> 

Thanks, I will fix it in the next version

> >> +error_release_group_hold:
> >> +	imx334_write_reg(imx334, IMX334_REG_HOLD, 1, 0);
> >> +	return ret;
> >> +}
> 
> Thanks,
> Andrey
> 
> >> +
> >> +/**
> >> + * imx334_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 imx334_set_ctrl(struct v4l2_ctrl *ctrl)
> >> +{
> >> +	struct imx334 *imx334 =
> >> +		container_of(ctrl->handler, struct imx334, ctrl_handler);
> >> +	u32 analog_gain;
> >> +	u32 exposure;
> >> +	int ret;
> >> +
> >> +	/* Set controls only if sensor is in power on state */
> >> +	if (!pm_runtime_get_if_in_use(imx334->dev))
> >> +		return 0;
> >> +
> >> +	/* Handle the cluster for both controls */
> >> +	switch (ctrl->id) {
> >> +	case V4L2_CID_VBLANK:
> >> +		imx334->lpfr = imx334->vblank_ctrl->val +
> >> +			imx334->cur_mode->height;
> >> +
> >> +		dev_dbg(imx334->dev, "Received vblank %u new lpfr %u",
> >> +			imx334->vblank_ctrl->val, imx334->lpfr);
> >> +
> >> +		ret = imx334_update_controls(imx334, imx334->cur_mode);
> >> +		break;
> >> +	case V4L2_CID_EXPOSURE:
> >> +		exposure = ctrl->val;
> >> +		analog_gain = imx334->again_ctrl->val;
> >> +
> >> +		dev_dbg(imx334->dev, "Received exp %u analog gain %u",
> >> +			exposure, analog_gain);
> >> +
> >> +		ret = imx334_update_exp_gain(imx334, exposure,
> analog_gain);
> >> +		break;
> >> +	default:
> >> +		dev_err(imx334->dev, "Invalid control %d", ctrl->id);
> >> +		ret = -EINVAL;
> >> +	}
> >> +
> >> +	pm_runtime_put(imx334->dev);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/* V4l2 subdevice control ops*/
> >> +static const struct v4l2_ctrl_ops imx334_ctrl_ops = {
> >> +	.s_ctrl = imx334_set_ctrl,
> >> +};
> >> +
> >> +/**
> >> + * imx334_enum_mbus_code() - Enumerate V4L2 sub-device mbus codes
> >> + * @sd: pointer to imx334 V4L2 sub-device structure
> >> + * @cfg: V4L2 sub-device pad configuration
> >> + * @code: V4L2 sub-device code enumeration need to be filled
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				 struct v4l2_subdev_pad_config *cfg,
> >> +				 struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	struct imx334 *imx334 = to_imx334(sd);
> >> +
> >> +	if (code->index > 0)
> >> +		return -EINVAL;
> >> +
> >> +	mutex_lock(&imx334->mutex);
> >
> > Do you need to lock ?
> >
Thanks, will be removed in the next version

> >> +	code->code = supported_mode.code;
> >> +	mutex_unlock(&imx334->mutex);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * imx334_enum_frame_size() - Enumerate V4L2 sub-device frame sizes
> >> + * @sd: pointer to imx334 V4L2 sub-device structure
> >> + * @cfg: V4L2 sub-device pad configuration
> >> + * @fsize: V4L2 sub-device size enumeration need to be filled
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_enum_frame_size(struct v4l2_subdev *sd,
> >> +				  struct v4l2_subdev_pad_config *cfg,
> >> +				  struct v4l2_subdev_frame_size_enum *fsize)
> >> +{
> >> +	struct imx334 *imx334 = to_imx334(sd);
> >> +
> >> +	if (fsize->index > 0)
> >> +		return -EINVAL;
> >> +
> >> +	mutex_lock(&imx334->mutex);
> >
> > Same here, no other subdev IOCTL can interfere with this one.
> >
> >> +	if (fsize->code != supported_mode.code) {
> >> +		mutex_unlock(&imx334->mutex);
> >> +		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;
> >> +	mutex_unlock(&imx334->mutex);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * imx334_fill_pad_format() - Fill subdevice pad format
> >> + *                              from selected sensor mode
> >> + * @imx334: pointer to imx334 device
> >> + * @mode: Pointer to imx334_mode sensor mode
> >> + * @fmt: V4L2 sub-device format need to be filled
> >> + */
> >> +static void imx334_fill_pad_format(struct imx334 *imx334,
> >> +				   const struct imx334_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;
> >
> > Running v4l2-compliance on this driver might report that you need to
> > set other fields of v4l2_subdev_format.format (at least the RAW colorspace
> > information. I wonder how encoding and quantization apply to a RAW sensor )
> >
I am not sure about this one, I referred to other imx sensor drivers, and they do fill just these four fields.
I will run the compliance test to verify it.

> >> +}
> >> +
> >> +/**
> >> + * imx334_get_pad_format() - Get subdevice pad format
> >> + * @sd: pointer to imx334 V4L2 sub-device structure
> >> + * @cfg: V4L2 sub-device pad configuration
> >> + * @fmt: V4L2 sub-device format need to be set
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_get_pad_format(struct v4l2_subdev *sd,
> >> +				 struct v4l2_subdev_pad_config *cfg,
> >> +				 struct v4l2_subdev_format *fmt)
> >> +{
> >> +	struct imx334 *imx334 = to_imx334(sd);
> >> +
> >> +	mutex_lock(&imx334->mutex);
> >> +
> >> +	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
> >> +		struct v4l2_mbus_framefmt *framefmt;
> >> +
> >> +		framefmt = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
> >> +		fmt->format = *framefmt;
> >> +	} else {
> >> +		imx334_fill_pad_format(imx334, imx334->cur_mode, fmt);
> >> +	}
> >> +
> >> +	mutex_unlock(&imx334->mutex);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * imx334_set_pad_format() - Set subdevice pad format
> >> + * @sd: pointer to imx334 V4L2 sub-device structure
> >> + * @cfg: V4L2 sub-device pad configuration
> >> + * @fmt: V4L2 sub-device format need to be set
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_set_pad_format(struct v4l2_subdev *sd,
> >> +				 struct v4l2_subdev_pad_config *cfg,
> >> +				 struct v4l2_subdev_format *fmt)
> >> +{
> >> +	struct imx334 *imx334 = to_imx334(sd);
> >> +	const struct imx334_mode *mode;
> >> +	int ret = 0;
> >> +
> >> +	mutex_lock(&imx334->mutex);
> >> +
> >> +	mode = &supported_mode;
> >> +	imx334_fill_pad_format(imx334, mode, fmt);
> >> +
> >> +	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
> >> +		struct v4l2_mbus_framefmt *framefmt;
> >> +
> >> +		framefmt = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
> >> +		*framefmt = fmt->format;
> >> +	} else {
> >> +		ret = imx334_update_controls(imx334, mode);
> >
> > How can controls change since you have a single supported format ?
If the user sets different VBLANK the lpfr will change, which will affect the exposure range
The rest of the controls won't change thou, so I will remove them from this func.

> >
> > I think with a single format get_pad_fmt and set_pad_fmt could be
> > implemented by a single function.
> >
> >> +		if (ret)
> >> +			dev_err(imx334->dev, "failed to update ctls");
> >> +
> >> +		imx334->cur_mode = mode;
> >> +	}
> >> +
> >> +	mutex_unlock(&imx334->mutex);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/**
> >> + * imx334_init_pad_cfg() - Initialize sub-device pad configuration
> >> + * @sd: pointer to imx334 V4L2 sub-device structure
> >> + * @cfg: V4L2 sub-device pad configuration
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_init_pad_cfg(struct v4l2_subdev *sd,
> >> +			       struct v4l2_subdev_pad_config *cfg)
> >> +{
> >> +	struct v4l2_subdev_format fmt = { 0 };
> >> +
> >> +	fmt.which = cfg ? V4L2_SUBDEV_FORMAT_TRY :
> V4L2_SUBDEV_FORMAT_ACTIVE;
> >> +	fmt.format.width = supported_mode.width;
> >> +	fmt.format.height = supported_mode.height;
> >> +	fmt.format.code = supported_mode.code;
> >> +	fmt.format.field = V4L2_FIELD_NONE;
> >
> > You don't use field in set_pad_format. Not a big deal though.
Some imx drivers are initialising it, so I am not sure whether I need it or not. I will check 

> >
> >> +
> >> +	return imx334_set_pad_format(sd, cfg, &fmt);
> >> +}
> >> +
> >> +/**
> >> + * imx334_start_streaming() - Start sensor stream
> >> + * @imx334: pointer to imx334 device
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_start_streaming(struct imx334 *imx334)
> >> +{
> >> +	const struct imx334_reg_list *reg_list;
> >> +	int ret;
> >> +
> >> +	/* Write sensor mode registers */
> >> +	reg_list = &imx334->cur_mode->reg_list;
> >> +	ret = imx334_write_regs(imx334, reg_list->regs,
> >> +				reg_list->num_of_regs);
> >> +	if (ret) {
> >> +		dev_err(imx334->dev, "fail to write initial registers");
> >> +		return ret;
> >> +	}
> >> +
> >> +	/* Setup handler will write actual exposure and gain */
> >> +	ret =  __v4l2_ctrl_handler_setup(imx334->sd.ctrl_handler);
> >> +	if (ret) {
> >> +		dev_err(imx334->dev, "fail to setup handler");
> >> +		return ret;
> >> +	}
> >> +
> >> +	/* Start streaming */
> >> +	ret = imx334_write_reg(imx334, IMX334_REG_MODE_SELECT,
> >> +			       1, IMX334_MODE_STREAMING);
> >> +	if (ret) {
> >> +		dev_err(imx334->dev, "fail to start streaming");
> >> +		return ret;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * imx334_stop_streaming() - Stop sensor stream
> >> + * @imx334: pointer to imx334 device
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_stop_streaming(struct imx334 *imx334)
> >> +{
> >> +	return imx334_write_reg(imx334, IMX334_REG_MODE_SELECT,
> >> +				1, IMX334_MODE_STANDBY);
> >> +}
> >> +
> >> +/**
> >> + * imx334_set_stream() - Enable sensor streaming
> >> + * @sd: pointer to imx334 subdevice
> >> + * @enable: Set to enable sensor streaming
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_set_stream(struct v4l2_subdev *sd, int enable)
> >> +{
> >> +	struct imx334 *imx334 = to_imx334(sd);
> >> +	int ret;
> >> +
> >> +	mutex_lock(&imx334->mutex);
> >> +
> >> +	if (imx334->streaming == enable) {
> >> +		mutex_unlock(&imx334->mutex);
> >> +		return 0;
> >> +	}
> >> +
> >> +	if (enable) {
> >> +		ret = pm_runtime_get_sync(imx334->dev);
> >> +		if (ret)
> >> +			goto error_power_off;
> >> +
> >> +		ret = imx334_start_streaming(imx334);
> >> +		if (ret)
> >> +			goto error_power_off;
> >> +	} else {
> >> +		imx334_stop_streaming(imx334);
> >> +		pm_runtime_put(imx334->dev);
> >> +	}
> >> +
> >> +	imx334->streaming = enable;
> >> +
> >> +	mutex_unlock(&imx334->mutex);
> >> +
> >> +	return 0;
> >> +
> >> +error_power_off:
> >> +	pm_runtime_put(imx334->dev);
> >> +	mutex_unlock(&imx334->mutex);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/**
> >> + * imx334_detect() - Detect imx334 sensor
> >> + * @imx334: pointer to imx334 device
> >> + *
> >> + * Return: 0 if successful, -EIO if sensor id does not match
> >> + */
> >> +static int imx334_detect(struct imx334 *imx334)
> >> +{
> >> +	int ret;
> >> +	u32 val;
> >> +
> >> +	ret = imx334_read_reg(imx334, IMX334_REG_ID, 2, &val);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	if (val != IMX334_ID) {
> >> +		dev_err(imx334->dev, "chip id mismatch: %x!=%x",
> >> +			IMX334_ID, val);
> >> +		return -EIO;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/* V4l2 subdevice ops */
> >> +static const struct v4l2_subdev_video_ops imx334_video_ops = {
> >> +	.s_stream = imx334_set_stream,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_pad_ops imx334_pad_ops = {
> >> +	.init_cfg = imx334_init_pad_cfg,
> >> +	.enum_mbus_code = imx334_enum_mbus_code,
> >> +	.enum_frame_size = imx334_enum_frame_size,
> >> +	.get_fmt = imx334_get_pad_format,
> >> +	.set_fmt = imx334_set_pad_format,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_ops imx334_subdev_ops = {
> >> +	.video = &imx334_video_ops,
> >> +	.pad = &imx334_pad_ops,
> >> +};
> >> +
> >> +static const struct media_entity_operations imx334_subdev_entity_ops = {
> >> +	.link_validate = v4l2_subdev_link_validate,
> >> +};
> >
> > Is link_validate called on sensor subdev ? My understanding is that
> > they're called on the sink entity, but I might be mistaken.
> >
> >> +
> >> +/**
> >> + * imx334_power_on() - Sensor power on sequence
> >> + * @dev: pointer to i2c device
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_power_on(struct device *dev)
> >> +{
> >> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >> +	struct imx334 *imx334 = to_imx334(sd);
> >> +	int ret;
> >> +
> >> +	gpiod_set_value_cansleep(imx334->reset_gpio, 1);
> >> +
> >> +	ret = clk_prepare_enable(imx334->inclk);
> >> +	if (ret) {
> >> +		dev_err(imx334->dev, "fail to enable inclk");
> >> +		goto error_reset;
> >> +	}
> >> +
> >> +	usleep_range(18000, 20000);
> >> +
> >> +	return 0;
> >> +
> >> +error_reset:
> >> +	gpiod_set_value_cansleep(imx334->reset_gpio, 0);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/**
> >> + * imx334_power_off() - Sensor power off sequence
> >> + * @dev: pointer to i2c device
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_power_off(struct device *dev)
> >> +{
> >> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >> +	struct imx334 *imx334 = to_imx334(sd);
> >> +
> >> +	gpiod_set_value_cansleep(imx334->reset_gpio, 0);
> >> +
> >> +	clk_disable_unprepare(imx334->inclk);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +/**
> >> + * imx334_init_controls() - Initialize sensor subdevice controls
> >> + * @imx334: pointer to imx334 device
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_init_controls(struct imx334 *imx334)
> >> +{
> >> +	struct v4l2_ctrl_handler *ctrl_hdlr = &imx334->ctrl_handler;
> >> +	const struct imx334_mode *mode = imx334->cur_mode;
> >> +	u32 hblank;
> >> +	u32 vblank;
> >> +	int ret;
> >> +
> >> +	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 5);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	/* Serialize controls with sensor device */
> >> +	ctrl_hdlr->lock = &imx334->mutex;
> >> +
> >> +	/* Initialize exposure and gain */
> >> +	imx334->exp_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> >> +					     &imx334_ctrl_ops,
> >> +					     V4L2_CID_EXPOSURE,
> >> +					     IMX334_EXPOSURE_MIN,
> >> +					     mode->lpfr,
> >> +					     IMX334_EXPOSURE_STEP,
> >> +					     IMX334_EXPOSURE_DEFAULT);
> >> +
> >> +	imx334->again_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> >> +					       &imx334_ctrl_ops,
> >> +					       V4L2_CID_ANALOGUE_GAIN,
> >> +					       IMX334_AGAIN_MIN,
> >> +					       IMX334_AGAIN_MAX,
> >> +					       IMX334_AGAIN_STEP,
> >> +					       IMX334_AGAIN_DEFAULT);
> >> +
> >> +	v4l2_ctrl_cluster(2, &imx334->exp_ctrl);
> >> +
> >> +	vblank = mode->lpfr - mode->height;
> >> +	imx334->vblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> >> +						&imx334_ctrl_ops,
> >> +						V4L2_CID_VBLANK,
> >> +						IMX334_LPFR_MIN - mode-
> >height,
> >> +						IMX334_LPFR_MAX - mode-
> >height,
> >> +						1, vblank);
> >> +
> >> +	/* Read only controls */
> >> +	imx334->pclk_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> >> +					      &imx334_ctrl_ops,
> >> +					      V4L2_CID_PIXEL_RATE,
> >> +					      mode->pclk, mode->pclk,
> >> +					      1, mode->pclk);
> >> +	if (imx334->pclk_ctrl)
> >> +		imx334->pclk_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >
> > You can set the READ_ONLY flags after the below:
> >          if (ctrl_hdlr->error)
> >
> > to avoid checking for the control validity here and below
> >
For V4L2_CID_PIXEL_RATE the read only flag is set by default so I will update this func for the next version

> >
> >> +
> >> +	hblank = mode->ppln - mode->width;
> >> +	imx334->hblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> >> +						&imx334_ctrl_ops,
> >> +						V4L2_CID_HBLANK,
> >> +						IMX334_REG_MIN,
> >> +						IMX334_REG_MAX,
> >> +						1, hblank);
> >> +	if (imx334->hblank_ctrl)
> >> +		imx334->hblank_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >> +
> >> +	if (ctrl_hdlr->error) {
> >> +		ret = ctrl_hdlr->error;
> >> +		dev_err(imx334->dev, "control init failed: %d", ret);
> >> +		goto error;
> >
> > You can free the handler here and return cltr_hdlr->error directly
> > here.
> >
> >> +	}
> >> +
> >> +	imx334->sd.ctrl_handler = ctrl_hdlr;
> >> +
> >> +	return 0;
> >> +
> >> +error:
> >> +	v4l2_ctrl_handler_free(ctrl_hdlr);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/**
> >> + * imx334_probe() - I2C client device binding
> >> + * @client: pointer to i2c client device
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_probe(struct i2c_client *client)
> >> +{
> >> +	struct imx334 *imx334;
> >> +	unsigned long rate;
> >> +	int ret;
> >> +
> >> +	imx334 = devm_kzalloc(&client->dev, sizeof(*imx334), GFP_KERNEL);
> >> +	if (!imx334)
> >> +		return -ENOMEM;
> >> +
> >> +	mutex_init(&imx334->mutex);
> >> +
> >> +	imx334->dev = &client->dev;
> >> +
> >> +	/* Initialize subdev */
> >> +	v4l2_i2c_subdev_init(&imx334->sd, client, &imx334_subdev_ops);
> >> +
> >> +	/* Request optional reset pin */
> >> +	imx334->reset_gpio = gpiod_get_optional(imx334->dev, "reset",
> >> +						GPIOD_OUT_LOW);
> >
> > devm_ ?
Thanks, I will use it

> >
> >> +	if (IS_ERR(imx334->reset_gpio)) {
> >> +		ret = PTR_ERR(imx334->reset_gpio);
> >> +		dev_err(imx334->dev, "failed to get reset gpio %d", ret);
> >> +		goto error_mutex_destroy;
> >> +	}
> >> +
> >> +	/* Get sensor input clock */
> >> +	imx334->inclk = devm_clk_get(imx334->dev, "inclk");
> >> +	if (IS_ERR(imx334->inclk)) {
> >> +		ret = PTR_ERR(imx334->inclk);
> >> +		dev_err(imx334->dev, "could not get inclk");
> >> +		goto error_mutex_destroy;
> >> +	}
> >> +
> >> +	rate = clk_get_rate(imx334->inclk);
> >> +	if (rate != IMX334_INCLK_RATE) {
> >> +		dev_err(imx334->dev, "inclk frequency mismatch");
> >> +		ret = -EINVAL;
> >> +		goto error_mutex_destroy;
> >> +	}
> >
> > You can intialize the mutex here to avoid a few goto here above
> >
> >> +
> >> +	ret = imx334_power_on(imx334->dev);
> >> +	if (ret) {
> >> +		dev_err(imx334->dev, "failed to power-on the sensor");
> >> +		goto error_mutex_destroy;
> >> +	}
> >> +
> >> +	/* Check module identity */
> >> +	ret = imx334_detect(imx334);
> >> +	if (ret) {
> >> +		dev_err(imx334->dev, "failed to find sensor: %d", ret);
> >> +		goto error_power_off;
> >> +	}
> >> +
> >> +	/* Set default mode to max resolution */
> >> +	imx334->cur_mode = &supported_mode;
> >> +	imx334->lpfr = imx334->cur_mode->lpfr;
> >> +
> >> +	ret = imx334_init_controls(imx334);
> >> +	if (ret) {
> >> +		dev_err(imx334->dev, "failed to init controls: %d", ret);
> >> +		goto error_power_off;
> >> +	}
> >> +
> >> +	/* Initialize subdev */
> >> +	imx334->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> >> +	imx334->sd.entity.ops = &imx334_subdev_entity_ops;
> >> +	imx334->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> >> +
> >> +	/* Initialize source pad */
> >> +	imx334->pad.flags = MEDIA_PAD_FL_SOURCE;
> >> +	ret = media_entity_pads_init(&imx334->sd.entity, 1, &imx334->pad);
> >> +	if (ret) {
> >> +		dev_err(imx334->dev, "failed to init entity pads: %d", ret);
> >> +		goto error_handler_free;
> >> +	}
> >> +
> >> +	ret = v4l2_async_register_subdev_sensor_common(&imx334->sd);
> >
> > _sensor_common() tries to parse the firware interface to search for
> > lens and flash subdevices. I don't see them mentioned in bindings, do
> > you need them or should this just be v4l2_async_register_subdev() ?
> >
> > Anyway, driver looks good, mostly minor comments
> > Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> >
> > Thanks
> >    j
> >
> >> +	if (ret < 0) {
> >> +		dev_err(imx334->dev,
> >> +			"failed to register async subdev: %d", ret);
> >> +		goto error_media_entity;
> >> +	}
> >> +
> >> +	pm_runtime_set_active(imx334->dev);
> >> +	pm_runtime_enable(imx334->dev);
> >> +	pm_runtime_idle(imx334->dev);
> >> +
> >> +	return 0;
> >> +
> >> +error_media_entity:
> >> +	media_entity_cleanup(&imx334->sd.entity);
> >> +error_handler_free:
> >> +	v4l2_ctrl_handler_free(imx334->sd.ctrl_handler);
> >> +error_power_off:
> >> +	imx334_power_off(imx334->dev);
> >> +error_mutex_destroy:
> >> +	mutex_destroy(&imx334->mutex);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/**
> >> + * imx334_remove() - I2C client device unbinding
> >> + * @client: pointer to I2C client device
> >> + *
> >> + * Return: 0 if successful, error code otherwise.
> >> + */
> >> +static int imx334_remove(struct i2c_client *client)
> >> +{
> >> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> >> +	struct imx334 *imx334 = to_imx334(sd);
> >> +
> >> +	v4l2_async_unregister_subdev(sd);
> >> +	media_entity_cleanup(&sd->entity);
> >> +	v4l2_ctrl_handler_free(sd->ctrl_handler);
> >> +
> >> +	pm_runtime_disable(&client->dev);
> >> +	pm_runtime_suspended(&client->dev);
> >> +
> >> +	mutex_destroy(&imx334->mutex);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct dev_pm_ops imx334_pm_ops = {
> >> +	SET_RUNTIME_PM_OPS(imx334_power_off, imx334_power_on, NULL)
> >> +};
> >> +
> >> +static const struct of_device_id imx334_of_match[] = {
> >> +	{ .compatible = "sony,imx334" },
> >> +	{ }
> >> +};
> >> +
> >> +MODULE_DEVICE_TABLE(of, imx334_of_match);
> >> +
> >> +static struct i2c_driver imx334_driver = {
> >> +	.probe_new = imx334_probe,
> >> +	.remove = imx334_remove,
> >> +	.driver = {
> >> +		.name = IMX334_DRV_NAME,
> >> +		.pm = &imx334_pm_ops,
> >> +		.of_match_table = imx334_of_match,
> >> +	},
> >> +};
> >> +
> >> +module_i2c_driver(imx334_driver);
> >> +
> >> +MODULE_DESCRIPTION("Sony imx334 sensor driver");
> >> +MODULE_LICENSE("GPL");
> >> --
> >> 2.11.0
> >>

Thanks,
Martina