Re: [PATCH v5 2/2] media: i2c: Add the ov7740 image sensor driver

From: Sakari Ailus
Date: Tue Nov 28 2017 - 07:06:31 EST

Hi Wenyou,

Thanks for the patch. Some comments below.

On Tue, Nov 28, 2017 at 01:22:59PM +0800, Wenyou Yang wrote:
> The ov7740 (color) image sensor is a high performance VGA CMOS
> image snesor, which supports for output formats: RAW RGB and YUV
> and image sizes: VGA, and QVGA, CIF and any size smaller.
>
> Signed-off-by: Songjun Wu <songjun.wu@xxxxxxxxxxxxx>
> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxxxxxx>
> ---
>
> Changes in v5:
> - Squash the driver and MAINTAINERS entry patches to one.
> - Precede the driver patch with the bindings patch.
>
> Changes in v4:
> - Assign 'val' a initial value to avoid warning: 'val' may be
> used uninitialized.
> - Rename REG_REG15 to avoid warning: "REG_REG15" redefined.
>
> Changes in v3:
> - Put the MAINTAINERS change to a separate patch.
>
> Changes in v2:
> - Split off the bindings into a separate patch.
> - Add a new entry to the MAINTAINERS file.
>
> MAINTAINERS | 8 +
> drivers/media/i2c/Kconfig | 8 +
> drivers/media/i2c/Makefile | 1 +
> drivers/media/i2c/ov7740.c | 1220 ++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 1237 insertions(+)
> create mode 100644 drivers/media/i2c/ov7740.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index aa71ab52fd76..19086a073ae9 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10053,6 +10053,14 @@ S: Maintained
> F: drivers/media/i2c/ov7670.c
> F: Documentation/devicetree/bindings/media/i2c/ov7670.txt
>
> +OMNIVISION OV7740 SENSOR DRIVER
> +M: Wenyou Yang <wenyou.yang@xxxxxxxxxxxxx>
> +L: linux-media@xxxxxxxxxxxxxxx
> +T: git git://linuxtv.org/media_tree.git
> +S: Maintained
> +F: drivers/media/i2c/ov7740.c
> +F: Documentation/devicetree/bindings/media/i2c/ov7740.txt
> +
> ONENAND FLASH DRIVER
> M: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> L: linux-mtd@xxxxxxxxxxxxxxxxxxx
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 3c6d6428f525..ac484bb82fae 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -665,6 +665,14 @@ config VIDEO_OV7670
> OV7670 VGA camera. It currently only works with the M88ALP01
> controller.
>
> +config VIDEO_OV7740
> + tristate "OmniVision OV7740 sensor support"
> + depends on I2C && VIDEO_V4L2
> + depends on MEDIA_CAMERA_SUPPORT
> + ---help---
> + This is a Video4Linux2 sensor-level driver for the OmniVision
> + OV7740 VGA camera sensor.
> +
> config VIDEO_OV9650
> tristate "OmniVision OV9650/OV9652 sensor support"
> depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index 548a9efce966..9b19ec7fcaf4 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -68,6 +68,7 @@ obj-$(CONFIG_VIDEO_OV5670) += ov5670.o
> obj-$(CONFIG_VIDEO_OV6650) += ov6650.o
> obj-$(CONFIG_VIDEO_OV7640) += ov7640.o
> obj-$(CONFIG_VIDEO_OV7670) += ov7670.o
> +obj-$(CONFIG_VIDEO_OV7740) += ov7740.o
> obj-$(CONFIG_VIDEO_OV9650) += ov9650.o
> obj-$(CONFIG_VIDEO_OV13858) += ov13858.o
> obj-$(CONFIG_VIDEO_MT9M032) += mt9m032.o
> diff --git a/drivers/media/i2c/ov7740.c b/drivers/media/i2c/ov7740.c
> new file mode 100644
> index 000000000000..b2ec015bf3f6
> --- /dev/null
> +++ b/drivers/media/i2c/ov7740.c
> @@ -0,0 +1,1220 @@
> +/*
> + * Copyright (c) 2017 Microchip Corporation.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version
> + * 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/gpio.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>

Do you need init.h?

> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-image-sizes.h>
> +#include <media/v4l2-subdev.h>
> +
> +#define REG_OUTSIZE_LSB 0x34
> +
> +/* OV7740 register tables */
> +#define REG_GAIN 0x00 /* Gain lower 8 bits (rest in vref) */
> +#define REG_BGAIN 0x01 /* blue gain */
> +#define REG_RGAIN 0x02 /* red gain */
> +#define REG_GGAIN 0x03 /* green gain */
> +#define REG_REG04 0x04 /* analog setting, dont change*/
> +#define REG_BAVG 0x05 /* b channel average */
> +#define REG_GAVG 0x06 /* g channel average */
> +#define REG_RAVG 0x07 /* r channel average */
> +
> +#define REG_REG0C 0x0C /* filp enable */
> +#define REG0C_IMG_FLIP 0x80
> +#define REG0C_IMG_MIRROR 0x40
> +
> +#define REG_REG0E 0x0E /* blc line */
> +#define REG_HAEC 0x0F /* auto exposure cntrl */
> +#define REG_AEC 0x10 /* auto exposure cntrl */
> +
> +#define REG_CLK 0x11 /* Clock control */
> +#define REG_REG55 0x55 /* Clock PLL DIV/PreDiv */
> +
> +#define REG_REG12 0x12
> +
> +#define REG_REG13 0x13 /* auto/manual AGC, AEC, Write Balance*/
> +#define REG13_AEC_EN 0x01
> +#define REG13_AGC_EN 0x04
> +
> +#define REG_REG14 0x14
> +#define REG_CTRL15 0x15
> +#define REG15_GAIN_MSB 0x03
> +
> +#define REG_REG16 0x16
> +
> +#define REG_MIDH 0x1C /* manufacture id byte */
> +#define REG_MIDL 0x1D /* manufacture id byre */
> +#define REG_PIDH 0x0A /* Product ID MSB */
> +#define REG_PIDL 0x0B /* Product ID LSB */
> +
> +#define REG_84 0x84 /* lots of stuff */
> +#define REG_REG38 0x38 /* sub-addr */
> +
> +#define REG_AHSTART 0x17 /* Horiz start high bits */
> +#define REG_AHSIZE 0x18
> +#define REG_AVSTART 0x19 /* Vert start high bits */
> +#define REG_AVSIZE 0x1A
> +#define REG_PSHFT 0x1b /* Pixel delay after HREF */
> +
> +#define REG_HOUTSIZE 0x31
> +#define REG_VOUTSIZE 0x32
> +#define REG_HVSIZEOFF 0x33
> +#define REG_REG34 0x34 /* DSP output size H/V LSB*/
> +
> +#define REG_ISP_CTRL00 0x80
> +#define ISPCTRL00_AWB_EN 0x10
> +#define ISPCTRL00_AWB_GAIN_EN 0x04
> +
> +#define REG_YGAIN 0xE2 /* ygain for contrast control */
> +
> +#define REG_YBRIGHT 0xE3
> +#define REG_SGNSET 0xE4
> +#define SGNSET_YBRIGHT_MASK 0x08
> +
> +#define REG_USAT 0xDD
> +#define REG_VSAT 0xDE
> +
> +
> +struct ov7740 {
> + struct v4l2_subdev subdev;
> +#if defined(CONFIG_MEDIA_CONTROLLER)
> + struct media_pad pad;
> +#endif
> + struct v4l2_mbus_framefmt format;
> + struct ov7740_pixfmt *fmt; /* Current format */
> + struct ov7740_framesize *frmsize;
> + struct regmap *regmap;
> + struct clk *xvclk;
> + struct v4l2_ctrl_handler ctrl_handler;
> + struct {
> + /* gain cluster */
> + struct v4l2_ctrl *auto_gain;
> + struct v4l2_ctrl *gain;
> + };
> + struct {
> + struct v4l2_ctrl *auto_wb;
> + struct v4l2_ctrl *blue_balance;
> + struct v4l2_ctrl *red_balance;
> + };
> + struct {
> + struct v4l2_ctrl *hflip;
> + struct v4l2_ctrl *vflip;
> + };
> + struct {
> + /* exposure cluster */
> + struct v4l2_ctrl *auto_exposure;
> + struct v4l2_ctrl *exposure;
> + };
> + struct {
> + /* saturation/hue cluster */
> + struct v4l2_ctrl *saturation;
> + struct v4l2_ctrl *hue;
> + };
> + struct v4l2_ctrl *brightness;
> + struct v4l2_ctrl *contrast;
> +
> + struct mutex mutex; /* To serialize asynchronus callbacks */
> + bool streaming; /* Streaming on/off */
> +
> + struct gpio_desc *resetb_gpio;
> + struct gpio_desc *pwdn_gpio;
> +};
> +
> +struct ov7740_pixfmt {
> + u32 mbus_code;
> + enum v4l2_colorspace colorspace;
> + const struct reg_sequence *regs;
> + u32 reg_num;
> +};
> +
> +struct ov7740_framesize {
> + u16 width;
> + u16 height;
> + const struct reg_sequence *regs;
> + u32 reg_num;
> +};
> +

Are the register lists below for a particular external clock frequency?

> +static const struct reg_sequence ov7740_vga[] = {
> + {0x55, 0x40},
> + {0x11, 0x02},
> +
> + {0xd5, 0x10},
> + {0x0c, 0x12},
> + {0x0d, 0x34},
> + {0x17, 0x25},
> + {0x18, 0xa0},
> + {0x19, 0x03},
> + {0x1a, 0xf0},
> + {0x1b, 0x89},
> + {0x22, 0x03},
> + {0x29, 0x18},
> + {0x2b, 0xf8},
> + {0x2c, 0x01},
> + {REG_HOUTSIZE, 0xa0},
> + {REG_VOUTSIZE, 0xf0},
> + {0x33, 0xc4},
> + {REG_OUTSIZE_LSB, 0x0},
> + {0x35, 0x05},
> + //{0x36, 0x3f},

Why?

> + {0x04, 0x60},
> + {0x27, 0x80},
> + {0x3d, 0x0f},
> + {0x3e, 0x80},
> + {0x3f, 0x40},
> + {0x40, 0x7f},
> + {0x41, 0x6a},
> + {0x42, 0x29},
> + {0x44, 0x22},
> + {0x45, 0x41},
> + {0x47, 0x02},
> + {0x49, 0x64},
> + {0x4a, 0xa1},
> + {0x4b, 0x40},
> + {0x4c, 0x1a},
> + {0x4d, 0x50},
> + {0x4e, 0x13},
> + {0x64, 0x00},
> + {0x67, 0x88},
> + {0x68, 0x1a},
> +
> + {0x14, 0x28},
> + {0x24, 0x3c},
> + {0x25, 0x30},
> + {0x26, 0x72},
> + {0x50, 0x97},
> + {0x51, 0x1f},
> + {0x52, 0x00},
> + {0x53, 0x00},
> + {0x20, 0x00},
> + {0x21, 0xcf},
> + {0x50, 0x4b},
> + {0x38, 0x14},
> + {0xe9, 0x00},
> + {0x56, 0x55},
> + {0x57, 0xff},
> + {0x58, 0xff},
> + {0x59, 0xff},
> + {0x5f, 0x04},
> + {0xec, 0x00},
> + {0x13, 0xff},
> +
> + //{0x80,0x7f},
> + {0x81, 0x3f},
> + {0x82, 0x32},
> + //{0x83, 0x01},

Yes, but why?

> + {0x38, 0x11},
> + {0x84, 0x70},
> + {0x85, 0x00},
> + {0x86, 0x03},
> + {0x87, 0x01},
> + {0x88, 0x05},
> + {0x89, 0x30},
> + {0x8d, 0x30},
> + {0x8f, 0x85},
> + {0x93, 0x30},
> + {0x95, 0x85},
> + {0x99, 0x30},
> + {0x9b, 0x85},
> +
> + {0x9c, 0x08},
> + {0x9d, 0x12},
> + {0x9e, 0x23},
> + {0x9f, 0x45},
> + {0xa0, 0x55},
> + {0xa1, 0x64},
> + {0xa2, 0x72},
> + {0xa3, 0x7f},
> + {0xa4, 0x8b},
> + {0xa5, 0x95},
> + {0xa6, 0xa7},
> + {0xa7, 0xb5},
> + {0xa8, 0xcb},
> + {0xa9, 0xdd},
> + {0xaa, 0xec},
> + {0xab, 0x1a},
> +
> + {0xce, 0x78},
> + {0xcf, 0x6e},
> + {0xd0, 0x0a},
> + {0xd1, 0x0c},
> + {0xd2, 0x84},
> + {0xd3, 0x90},
> + {0xd4, 0x1e},
> +
> + {0x5a, 0x24},
> + {0x5b, 0x1f},
> + {0x5c, 0x88},
> + {0x5d, 0x60},
> +
> + {0xac, 0x6e},
> + {0xbe, 0xff},
> + {0xbf, 0x00},
> +
> + {0x0f, 0x1d},
> + {0x0f, 0x1f},
> +};
> +
> +static struct ov7740_framesize ov7740_framesizes[] = {

const?

Same for a number of structs below.

> + {
> + .width = VGA_WIDTH,
> + .height = VGA_HEIGHT,
> + .regs = ov7740_vga,
> + .reg_num = ARRAY_SIZE(ov7740_vga),
> + },
> +};
> +
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +static int ov7740_get_register(struct v4l2_subdev *sd,
> + struct v4l2_dbg_register *reg)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> + struct regmap *regmap = ov7740->regmap;
> + unsigned int val = 0;
> + int ret;
> +
> + ret = regmap_read(regmap, reg->reg & 0xff, &val);
> + reg->val = val;
> + reg->size = 1;
> +
> + return 0;
> +}
> +
> +static int ov7740_set_register(struct v4l2_subdev *sd,
> + const struct v4l2_dbg_register *reg)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> + struct regmap *regmap = ov7740->regmap;
> +
> + regmap_write(regmap, reg->reg & 0xff, reg->val & 0xff);
> +
> + return 0;
> +}
> +#endif
> +
> +static int ov7740_set_power(struct v4l2_subdev *sd, int on)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> +
> + if (ov7740->pwdn_gpio)
> + gpiod_direction_output(ov7740->pwdn_gpio, !on);
> + if (on && ov7740->resetb_gpio) {
> + gpiod_set_value(ov7740->resetb_gpio, 1);
> + usleep_range(500, 1000);
> + gpiod_set_value(ov7740->resetb_gpio, 0);
> + usleep_range(3000, 5000);
> + }
> +
> + return 0;
> +}
> +
> +static struct v4l2_subdev_core_ops ov7740_subdev_core_ops = {
> + .log_status = v4l2_ctrl_subdev_log_status,
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> + .g_register = ov7740_get_register,
> + .s_register = ov7740_set_register,
> +#endif
> + .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
> + .unsubscribe_event = v4l2_event_subdev_unsubscribe,
> +};
> +
> +static int ov7740_set_white_balance(struct ov7740 *ov7740, int awb)
> +{
> + struct regmap *regmap = ov7740->regmap;
> + unsigned int value;
> + int ret;
> +
> + ret = regmap_read(regmap, REG_ISP_CTRL00, &value);
> + if (!ret) {
> + if (awb)
> + value |= (ISPCTRL00_AWB_EN | ISPCTRL00_AWB_GAIN_EN);
> + else
> + value &= ~(ISPCTRL00_AWB_EN | ISPCTRL00_AWB_GAIN_EN);
> + ret = regmap_write(regmap, REG_ISP_CTRL00, value);
> + if (ret)
> + return ret;
> + }
> +
> + if (!awb) {
> + ret = regmap_write(regmap, REG_BGAIN,
> + ov7740->blue_balance->val);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(regmap, REG_RGAIN, ov7740->red_balance->val);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ov7740_set_saturation(struct regmap *regmap, int value)
> +{
> + int ret;
> +
> + ret = regmap_write(regmap, REG_USAT, (unsigned char)value);

ret is not checked.

> + ret = regmap_write(regmap, REG_VSAT, (unsigned char)value);
> +
> + return ret;
> +}
> +
> +static int ov7740_set_gain(struct regmap *regmap, int value)
> +{
> + int ret;
> +
> + ret = regmap_write(regmap, REG_GAIN, value & 0xff);
> + if (ret)
> + return ret;
> +
> + ret = regmap_update_bits(regmap, REG_CTRL15,
> + REG15_GAIN_MSB, (value >> 8) & 0x3);
> + if (!ret)
> + ret = regmap_update_bits(regmap, REG_REG13, REG13_AGC_EN, 0);
> +
> + return ret;
> +}
> +
> +static int ov7740_set_autogain(struct regmap *regmap, int value)
> +{
> + unsigned int reg;
> + int ret;
> +
> + ret = regmap_read(regmap, REG_REG13, &reg);
> + if (ret)
> + return ret;
> + if (value)
> + reg |= REG13_AGC_EN;
> + else
> + reg &= ~REG13_AGC_EN;
> + return regmap_write(regmap, REG_REG13, reg);
> +}
> +
> +static int ov7740_set_brightness(struct regmap *regmap, int value)
> +{
> + /* Turn off AEC/AGC */
> + regmap_update_bits(regmap, REG_REG13, REG13_AEC_EN, 0);
> + regmap_update_bits(regmap, REG_REG13, REG13_AGC_EN, 0);
> +
> + if (value >= 0) {
> + regmap_write(regmap, REG_YBRIGHT, (unsigned char)value);
> + regmap_update_bits(regmap, REG_SGNSET, SGNSET_YBRIGHT_MASK, 0);
> + } else{
> + regmap_write(regmap, REG_YBRIGHT, (unsigned char)(-value));
> + regmap_update_bits(regmap, REG_SGNSET, SGNSET_YBRIGHT_MASK, 1);
> + }
> +
> + return 0;
> +}
> +
> +static int ov7740_set_contrast(struct regmap *regmap, int value)
> +{
> + return regmap_write(regmap, REG_YGAIN, (unsigned char)value);
> +}
> +
> +static int ov7740_get_gain(struct ov7740 *ov7740, struct v4l2_ctrl *ctrl)
> +{
> + struct regmap *regmap = ov7740->regmap;
> + unsigned int value0, value1;
> + int ret;
> +
> + if (!ctrl->val)
> + return 0;
> +
> + ret = regmap_read(regmap, REG_GAIN, &value0);
> + if (ret)
> + return ret;
> + ret = regmap_read(regmap, REG_CTRL15, &value1);
> + if (ret)
> + return ret;
> +
> + ov7740->gain->val = (value1 << 8) | (value0 & 0xff);
> +
> + return 0;
> +}
> +
> +static int ov7740_set_exp(struct regmap *regmap, int value)
> +{
> + int ret;
> +
> + /* Turn off AEC/AGC */
> + ret = regmap_update_bits(regmap, REG_REG13,
> + REG13_AEC_EN | REG13_AGC_EN, 0);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(regmap, REG_AEC, (unsigned char)value);
> + if (ret)
> + return ret;
> +
> + return regmap_write(regmap, REG_HAEC, (unsigned char)(value >> 8));
> +}
> +
> +static int ov7740_set_autoexp(struct regmap *regmap,
> + enum v4l2_exposure_auto_type value)
> +{
> + unsigned int reg;
> + int ret;
> +
> + ret = regmap_read(regmap, REG_REG13, &reg);
> + if (!ret) {
> + if (value == V4L2_EXPOSURE_AUTO)
> + reg |= (REG13_AEC_EN | REG13_AGC_EN);
> + else
> + reg &= ~(REG13_AEC_EN | REG13_AGC_EN);
> + ret = regmap_write(regmap, REG_REG13, reg);
> + }
> +
> + return ret;
> +}
> +
> +
> +static int ov7740_get_volatile_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct ov7740 *ov7740 = container_of(ctrl->handler,
> + struct ov7740, ctrl_handler);
> + int ret;
> +
> + switch (ctrl->id) {
> + case V4L2_CID_AUTOGAIN:
> + ret = ov7740_get_gain(ov7740, ctrl);
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> + return ret;
> +}
> +
> +static int ov7740_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct ov7740 *ov7740 = container_of(ctrl->handler,
> + struct ov7740, ctrl_handler);
> + struct i2c_client *client = v4l2_get_subdevdata(&ov7740->subdev);
> + struct regmap *regmap = ov7740->regmap;
> + int ret;
> + u8 val = 0;
> +
> + if (pm_runtime_get_if_in_use(&client->dev) <= 0)
> + return 0;
> +
> + switch (ctrl->id) {
> + case V4L2_CID_AUTO_WHITE_BALANCE:
> + ret = ov7740_set_white_balance(ov7740, ctrl->val);
> + break;
> + case V4L2_CID_SATURATION:
> + ret = ov7740_set_saturation(regmap, ctrl->val);
> + break;
> + case V4L2_CID_BRIGHTNESS:
> + ret = ov7740_set_brightness(regmap, ctrl->val);
> + break;
> + case V4L2_CID_CONTRAST:
> + ret = ov7740_set_contrast(regmap, ctrl->val);
> + break;
> + case V4L2_CID_VFLIP:
> + ret = regmap_update_bits(regmap, REG_REG0C,
> + REG0C_IMG_FLIP, val);
> + break;
> + case V4L2_CID_HFLIP:
> + val = ctrl->val ? REG0C_IMG_MIRROR : 0x00;
> + ret = regmap_update_bits(regmap, REG_REG0C,
> + REG0C_IMG_MIRROR, val);
> + break;
> + case V4L2_CID_AUTOGAIN:
> + if (!ctrl->val)
> + return ov7740_set_gain(regmap, ov7740->gain->val);
> +
> + ret = ov7740_set_autogain(regmap, ctrl->val);
> + break;
> +
> + case V4L2_CID_EXPOSURE_AUTO:
> + if (ctrl->val == V4L2_EXPOSURE_MANUAL)
> + return ov7740_set_exp(regmap, ov7740->exposure->val);
> +
> + ret = ov7740_set_autoexp(regmap, ctrl->val);
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + pm_runtime_put(&client->dev);
> +
> + return ret;
> +}
> +
> +static const struct v4l2_ctrl_ops ov7740_ctrl_ops = {
> + .g_volatile_ctrl = ov7740_get_volatile_ctrl,
> + .s_ctrl = ov7740_set_ctrl,
> +};
> +
> +static int ov7740_start_streaming(struct ov7740 *ov7740)
> +{
> + int ret;
> +
> + /* Apply customized values from user */
> + ret = __v4l2_ctrl_handler_setup(ov7740->subdev.ctrl_handler);
> + if (ret)
> + return ret;

return __v4l2_ctrl_handler_setup(...);

You could as well move this to where it's being called, there's a single
instance.

That would make it easier to see that the sensor is probably starting the
stream based on its power on or mode register list. Shouldn't you set the
controls before starting streaming?

> +
> + return 0;
> +}
> +static int ov7740_set_stream(struct v4l2_subdev *sd, int enable)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> + struct i2c_client *client = v4l2_get_subdevdata(sd);
> + int ret = 0;
> +
> + mutex_lock(&ov7740->mutex);
> + if (ov7740->streaming == enable) {
> + mutex_unlock(&ov7740->mutex);
> + return 0;
> + }
> +
> + if (enable) {
> + ret = pm_runtime_get_sync(&client->dev);
> + if (ret < 0) {
> + pm_runtime_put_noidle(&client->dev);
> + goto err_unlock;
> + }
> +
> + ret = ov7740_start_streaming(ov7740);
> + if (ret)
> + goto err_rpm_put;
> + } else {
> + pm_runtime_put(&client->dev);
> + }
> +
> + ov7740->streaming = enable;
> +
> + mutex_unlock(&ov7740->mutex);
> + return ret;
> +
> +err_rpm_put:
> + pm_runtime_put(&client->dev);
> +err_unlock:
> + mutex_unlock(&ov7740->mutex);
> + return ret;
> +}
> +
> +static int ov7740_get_parm(struct v4l2_subdev *sd,
> + struct v4l2_streamparm *parms)
> +{
> + struct v4l2_captureparm *cp = &parms->parm.capture;
> + struct v4l2_fract *tpf = &cp->timeperframe;
> +
> + if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> + return -EINVAL;
> +
> + memset(cp, 0, sizeof(struct v4l2_captureparm));
> + cp->capability = V4L2_CAP_TIMEPERFRAME;
> +
> + tpf->numerator = 1;
> + tpf->denominator = 60;

You implement also [gs]_frame_interval in pad ops. Do you have a need for
this?

It'd be better if sensor drivers just implemented one of these APIs to
select the frame interval ([gs]_frame_interval), not both.

> +
> + return 0;
> +}
> +
> +static int ov7740_set_parm(struct v4l2_subdev *sd,
> + struct v4l2_streamparm *parms)
> +{
> + struct v4l2_captureparm *cp = &parms->parm.capture;
> + struct v4l2_fract *tpf = &cp->timeperframe;
> +
> + if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> + return -EINVAL;
> + if (cp->extendedmode != 0)
> + return -EINVAL;
> +
> + cp->capability = V4L2_CAP_TIMEPERFRAME;
> +
> + tpf->numerator = 1;
> + tpf->denominator = 60;
> +
> + return 0;
> +}
> +
> +static struct v4l2_subdev_video_ops ov7740_subdev_video_ops = {

const?

> + .s_stream = ov7740_set_stream,
> + .s_parm = ov7740_set_parm,
> + .g_parm = ov7740_get_parm,
> +};
> +
> +static const struct reg_sequence ov7740_format_yuyv[] = {
> + {0x12, 0x00},
> + {0x36, 0x3f},
> + {0x80, 0x7f},
> + {0x83, 0x01},
> +};
> +
> +static const struct reg_sequence ov7740_format_bggr8[] = {
> + {0x36, 0x2f},
> + {0x80, 0x01},
> + {0x83, 0x04},
> +};
> +
> +static struct ov7740_pixfmt ov7740_formats[] = {
> + {
> + .mbus_code = MEDIA_BUS_FMT_YUYV8_2X8,
> + .colorspace = V4L2_COLORSPACE_SRGB,
> + .regs = ov7740_format_yuyv,
> + .reg_num = ARRAY_SIZE(ov7740_format_yuyv),
> + },
> + {
> + .mbus_code = MEDIA_BUS_FMT_SBGGR8_1X8,
> + .colorspace = V4L2_COLORSPACE_SRGB,
> + .regs = ov7740_format_bggr8,
> + .reg_num = ARRAY_SIZE(ov7740_format_bggr8),
> + }
> +};
> +#define N_OV7740_FMTS ARRAY_SIZE(ov7740_formats)
> +
> +static int ov7740_enum_mbus_code(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_mbus_code_enum *code)
> +{
> + if (code->pad || code->index >= N_OV7740_FMTS)
> + return -EINVAL;
> +
> + code->code = ov7740_formats[code->index].mbus_code;
> +
> + return 0;
> +}
> +
> +static int ov7740_enum_frame_interval(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_frame_interval_enum *fie)
> +{
> + if (fie->pad)
> + return -EINVAL;
> +
> + if (fie->index >= 1)
> + return -EINVAL;
> +
> + if ((fie->width != VGA_WIDTH) || (fie->height != VGA_HEIGHT))
> + return -EINVAL;
> +
> + fie->interval.numerator = 1;
> + fie->interval.denominator = 60;
> +
> + return 0;
> +}
> +
> +static int ov7740_enum_frame_size(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_frame_size_enum *fse)
> +{
> + if (fse->pad)
> + return -EINVAL;
> +
> + if (fse->index > 0)
> + return -EINVAL;
> +
> + fse->min_width = fse->max_width = VGA_WIDTH;
> + fse->min_height = fse->max_height = VGA_HEIGHT;
> +
> + return 0;
> +}
> +
> +static int ov7740_try_fmt_internal(struct v4l2_subdev *sd,
> + struct v4l2_mbus_framefmt *fmt,
> + struct ov7740_pixfmt **ret_fmt,
> + struct ov7740_framesize **ret_frmsize)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> + struct ov7740_framesize *fsize = &ov7740_framesizes[0];
> + int index, i;
> +
> + for (index = 0; index < N_OV7740_FMTS; index++) {
> + if (ov7740_formats[index].mbus_code == fmt->code)
> + break;
> + }
> + if (index >= N_OV7740_FMTS) {
> + /* default to first format */
> + index = 0;
> + fmt->code = ov7740_formats[0].mbus_code;
> + }
> + if (ret_fmt != NULL)
> + *ret_fmt = ov7740_formats + index;
> +
> + for (i = 0; i < ARRAY_SIZE(ov7740_framesizes); i++) {
> + if ((fsize->width >= fmt->width) &&
> + (fsize->height >= fmt->height)) {
> + fmt->width = fsize->width;
> + fmt->height = fsize->height;
> + break;
> + }
> +
> + fsize++;
> + }
> +
> + if (ret_frmsize != NULL)
> + *ret_frmsize = fsize;
> +
> + fmt->field = V4L2_FIELD_NONE;
> + fmt->colorspace = ov7740_formats[index].colorspace;
> +
> + ov7740->format = *fmt;
> +
> + return 0;
> +}
> +
> +static int ov7740_set_fmt(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_format *format)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> + struct ov7740_pixfmt *ovfmt;
> + struct ov7740_framesize *fsize;
> +#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> + struct v4l2_mbus_framefmt *mbus_fmt;
> +#endif
> + int ret;
> +
> + mutex_lock(&ov7740->mutex);
> + if (format->pad) {
> + ret = -EINVAL;
> + goto error;
> + }
> +
> + if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> + ret = ov7740_try_fmt_internal(sd, &format->format, NULL, NULL);
> + if (ret)
> + goto error;
> +#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> + mbus_fmt = v4l2_subdev_get_try_format(sd, cfg, format->pad);
> + *mbus_fmt = format->format;
> +
> + mutex_unlock(&ov7740->mutex);
> + return 0;
> +#else
> + ret = -ENOTTY;
> + goto error;
> +#endif
> + }
> +
> + ret = ov7740_try_fmt_internal(sd, &format->format, &ovfmt, &fsize);
> + if (ret)
> + goto error;
> +
> + if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
> + regmap_multi_reg_write(ov7740->regmap,
> + ovfmt->regs, ovfmt->reg_num);

What if streaming is started without calling set_fmt after the device is
powered on?

These should probably be written when streaming is started.

> +
> + regmap_multi_reg_write(ov7740->regmap,
> + fsize->regs, fsize->reg_num);
> + }
> +
> + ov7740->fmt = ovfmt;
> +
> + mutex_unlock(&ov7740->mutex);
> + return 0;
> +
> +error:
> + mutex_unlock(&ov7740->mutex);
> + return ret;
> +}
> +
> +static int ov7740_get_fmt(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_format *format)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> +#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> + struct v4l2_mbus_framefmt *mbus_fmt;
> +#endif
> + int ret = 0;
> +
> + mutex_lock(&ov7740->mutex);
> + if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> +#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> + mbus_fmt = v4l2_subdev_get_try_format(sd, cfg, 0);
> + format->format = *mbus_fmt;
> + ret = 0;
> +#else
> + ret = -ENOTTY;
> +#endif
> + } else {
> + format->format = ov7740->format;
> + }
> + mutex_unlock(&ov7740->mutex);
> +
> + return ret;
> +}
> +
> +static const struct v4l2_subdev_pad_ops ov7740_subdev_pad_ops = {
> + .enum_frame_interval = ov7740_enum_frame_interval,
> + .enum_frame_size = ov7740_enum_frame_size,
> + .enum_mbus_code = ov7740_enum_mbus_code,
> + .get_fmt = ov7740_get_fmt,
> + .set_fmt = ov7740_set_fmt,
> +};
> +
> +static struct v4l2_subdev_ops ov7740_subdev_ops = {
> + .core = &ov7740_subdev_core_ops,
> + .video = &ov7740_subdev_video_ops,
> + .pad = &ov7740_subdev_pad_ops,
> +};
> +
> +static void ov7740_get_default_format(struct v4l2_subdev *sd,
> + struct v4l2_mbus_framefmt *format)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> +
> + format->width = ov7740->frmsize->width;
> + format->height = ov7740->frmsize->height;
> + format->colorspace = ov7740->fmt->colorspace;
> + format->code = ov7740->fmt->mbus_code;
> + format->field = V4L2_FIELD_NONE;
> +}
> +
> +#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> +static int ov7740_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> + struct v4l2_mbus_framefmt *format =
> + v4l2_subdev_get_try_format(sd, fh->pad, 0);
> +
> + mutex_lock(&ov7740->mutex);
> + ov7740_get_default_format(sd, format);
> + mutex_unlock(&ov7740->mutex);
> +
> + return 0;
> +}
> +
> +static const struct v4l2_subdev_internal_ops ov7740_subdev_internal_ops = {
> + .open = ov7740_open,
> +};
> +#endif
> +
> +static int ov7740_probe_dt(struct i2c_client *client,
> + struct ov7740 *ov7740)
> +{
> + ov7740->resetb_gpio = devm_gpiod_get_optional(&client->dev, "reset",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(ov7740->resetb_gpio)) {
> + dev_info(&client->dev, "can't get %s GPIO\n", "reset");
> + return PTR_ERR(ov7740->resetb_gpio);
> + }
> +
> + ov7740->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "powerdown",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(ov7740->pwdn_gpio)) {
> + dev_info(&client->dev, "can't get %s GPIO\n", "powerdown");
> + return PTR_ERR(ov7740->pwdn_gpio);
> + }
> +
> + return 0;
> +}
> +
> +static int ov7740_detect(struct ov7740 *ov7740)
> +{
> + struct regmap *regmap = ov7740->regmap;
> + unsigned int midh, midl, pidh, pidl;
> + int ret;
> +
> + ret = regmap_read(regmap, REG_MIDH, &midh);
> + if (ret)
> + return ret;
> + if (midh != 0x7f)
> + return -ENODEV;
> +
> + ret = regmap_read(regmap, REG_MIDL, &midl);
> + if (ret)
> + return ret;
> + if (midl != 0xa2)
> + return -ENODEV;
> +
> + ret = regmap_read(regmap, REG_PIDH, &pidh);
> + if (ret)
> + return ret;
> + if (pidh != 0x77)
> + return -ENODEV;
> +
> + ret = regmap_read(regmap, REG_PIDL, &pidl);
> + if (ret)
> + return ret;
> + if ((pidl != 0x40) && (pidl != 0x41) && (pidl != 0x42))
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static int ov7740_init_controls(struct ov7740 *ov7740)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&ov7740->subdev);
> + struct v4l2_ctrl_handler *ctrl_hdlr = &ov7740->ctrl_handler;
> + int ret;
> +
> + ret = v4l2_ctrl_handler_init(ctrl_hdlr, 2);
> + if (ret < 0)
> + return ret;
> +
> + ctrl_hdlr->lock = &ov7740->mutex;
> + ov7740->auto_wb = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_AUTO_WHITE_BALANCE,
> + 0, 1, 1, 1);
> + ov7740->blue_balance = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_BLUE_BALANCE,
> + 0, 0xff, 1, 0x80);
> + ov7740->red_balance = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_RED_BALANCE,
> + 0, 0xff, 1, 0x80);
> +
> + ov7740->brightness = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_BRIGHTNESS,
> + -255, 255, 1, 0);
> + ov7740->contrast = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_CONTRAST,
> + 0, 127, 1, 0x20);
> + ov7740->saturation = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_SATURATION, 0, 256, 1, 0x80);
> + ov7740->hflip = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_HFLIP, 0, 1, 1, 0);
> + ov7740->vflip = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_VFLIP, 0, 1, 1, 0);
> + ov7740->gain = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_GAIN, 0, 1023, 1, 500);
> + ov7740->auto_gain = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
> + ov7740->exposure = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
> + V4L2_CID_EXPOSURE, 0, 65535, 1, 500);
> + ov7740->auto_exposure = v4l2_ctrl_new_std_menu(ctrl_hdlr,
> + &ov7740_ctrl_ops,
> + V4L2_CID_EXPOSURE_AUTO,
> + V4L2_EXPOSURE_MANUAL, 0,
> + V4L2_EXPOSURE_AUTO);
> +
> + ov7740->gain->flags |= V4L2_CTRL_FLAG_VOLATILE;
> + ov7740->exposure->flags |= V4L2_CTRL_FLAG_VOLATILE;
> +
> + v4l2_ctrl_auto_cluster(3, &ov7740->auto_wb, 0, false);
> + v4l2_ctrl_auto_cluster(2, &ov7740->auto_gain, 0, true);
> + v4l2_ctrl_auto_cluster(2, &ov7740->auto_exposure,
> + V4L2_EXPOSURE_MANUAL, false);
> + v4l2_ctrl_cluster(2, &ov7740->hflip);
> +
> + ret = v4l2_ctrl_handler_setup(ctrl_hdlr);
> + if (ret) {
> + dev_err(&client->dev, "%s control init failed (%d)\n",
> + __func__, ret);
> + goto error;
> + }
> +
> + ov7740->subdev.ctrl_handler = ctrl_hdlr;
> + return 0;
> +
> +error:
> + v4l2_ctrl_handler_free(ctrl_hdlr);
> + mutex_destroy(&ov7740->mutex);
> + return ret;
> +}
> +
> +static void ov7740_free_controls(struct ov7740 *ov7740)
> +{
> + v4l2_ctrl_handler_free(ov7740->subdev.ctrl_handler);
> + mutex_destroy(&ov7740->mutex);
> +}
> +
> +#define OV7740_MAX_REGISTER 0xff
> +static const struct regmap_config ov7740_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = OV7740_MAX_REGISTER,
> +};
> +
> +static int ov7740_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct ov7740 *ov7740;
> + struct v4l2_subdev *sd;
> + int ret;
> +
> + if (!i2c_check_functionality(client->adapter,
> + I2C_FUNC_SMBUS_BYTE_DATA)) {
> + dev_err(&client->dev,
> + "OV7740: I2C-Adapter doesn't support SMBUS\n");
> + return -EIO;
> + }
> +
> + ov7740 = devm_kzalloc(&client->dev, sizeof(*ov7740), GFP_KERNEL);
> + if (!ov7740)
> + return -ENOMEM;
> +
> + ov7740->xvclk = devm_clk_get(&client->dev, "xvclk");
> + if (IS_ERR(ov7740->xvclk)) {
> + ret = PTR_ERR(ov7740->xvclk);
> + dev_err(&client->dev,
> + "OV7740: fail to get xvclk: %d\n", ret);
> + return ret;
> + }
> +
> + ret = ov7740_probe_dt(client, ov7740);
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(ov7740->xvclk);
> + if (ret)
> + return ret;
> +
> + ov7740->regmap = devm_regmap_init_i2c(client, &ov7740_regmap_config);
> + if (IS_ERR(ov7740->regmap)) {
> + ret = PTR_ERR(ov7740->regmap);
> + dev_err(&client->dev, "Failed to allocate register map: %d\n",
> + ret);
> + goto error_regmap_init;
> + }
> +
> + sd = &ov7740->subdev;
> + client->flags |= I2C_CLIENT_SCCB;
> + v4l2_i2c_subdev_init(sd, client, &ov7740_subdev_ops);
> +
> +#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> + sd->internal_ops = &ov7740_subdev_internal_ops;
> + sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +#endif
> +
> +#if defined(CONFIG_MEDIA_CONTROLLER)
> + ov7740->pad.flags = MEDIA_PAD_FL_SOURCE;
> + sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
> + ret = media_entity_pads_init(&sd->entity, 1, &ov7740->pad);
> + if (ret)
> + goto error_regmap_init;
> +#endif
> +
> + ov7740_set_power(sd, 1);
> +
> + ret = ov7740_detect(ov7740);
> + if (ret)
> + goto error_detect;
> +
> + mutex_init(&ov7740->mutex);
> +
> + ret = ov7740_init_controls(ov7740);
> + if (ret)
> + goto error_init_controls;
> +
> + v4l_info(client, "chip found @ 0x%02x (%s)\n",
> + client->addr << 1, client->adapter->name);
> +
> + ov7740->fmt = &ov7740_formats[0];
> + ov7740->frmsize = &ov7740_framesizes[0];
> +
> + ov7740_get_default_format(sd, &ov7740->format);
> +
> + ret = v4l2_async_register_subdev(sd);
> + if (ret)
> + goto error_async_register;
> +
> + pm_runtime_get_noresume(&client->dev);
> + pm_runtime_set_active(&client->dev);
> + pm_runtime_enable(&client->dev);
> + pm_runtime_put(&client->dev);

You can use pm_runtime_idle() to replace get_noresume + put.

> +
> + return 0;
> +
> +error_async_register:
> + v4l2_ctrl_handler_free(ov7740->subdev.ctrl_handler);
> +error_init_controls:
> + ov7740_free_controls(ov7740);
> + ov7740_set_power(sd, 0);
> +error_detect:

ov7740_set_power(sd, 0) here?

> + media_entity_cleanup(&ov7740->subdev.entity);
> +error_regmap_init:
> + clk_disable_unprepare(ov7740->xvclk);
> +
> + return ret;
> +}
> +
> +static int ov7740_remove(struct i2c_client *client)
> +{
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> +
> + clk_disable_unprepare(ov7740->xvclk);
> + mutex_destroy(&ov7740->mutex);
> + v4l2_ctrl_handler_free(ov7740->subdev.ctrl_handler);
> +#if defined(CONFIG_MEDIA_CONTROLLER)
> + media_entity_cleanup(&ov7740->subdev.entity);
> +#endif
> + v4l2_async_unregister_subdev(sd);
> + ov7740_free_controls(ov7740);
> +
> + pm_runtime_get_sync(&client->dev);
> + pm_runtime_disable(&client->dev);
> + pm_runtime_set_suspended(&client->dev);
> + pm_runtime_put_noidle(&client->dev);

ov7740_set_power(sd, 0) if the device was suspended.

I'd think the smiapp driver does this generally right. Think about how this
works if runtime PM is disabled.

> +
> + return 0;
> +}
> +
> +static int __maybe_unused ov7740_runtime_suspend(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> +
> + clk_disable_unprepare(ov7740->xvclk);
> + ov7740_set_power(sd, 0);

How about moving clock control to ov7740_set_power()? Clock and the GPIOs
appear to be always controller together, aren't they?

> +
> + return 0;
> +}
> +
> +static int __maybe_unused ov7740_runtime_resume(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
> +
> + ov7740_set_power(sd, 1);
> + return clk_prepare_enable(ov7740->xvclk);
> +}
> +
> +static const struct i2c_device_id ov7740_id[] = {
> + { "ov7740", 0 },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ov7740_id);
> +
> +static const struct dev_pm_ops ov7740_pm_ops = {
> + SET_RUNTIME_PM_OPS(ov7740_runtime_suspend, ov7740_runtime_resume, NULL)
> +};
> +
> +static const struct of_device_id ov7740_of_match[] = {
> + {.compatible = "ovti,ov7740", },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, ov7740_of_match);
> +

Extra newline.

> +
> +static struct i2c_driver ov7740_i2c_driver = {
> + .driver = {
> + .name = "ov7740",
> + .pm = &ov7740_pm_ops,
> + .of_match_table = of_match_ptr(ov7740_of_match),
> + },
> + .probe = ov7740_probe,
> + .remove = ov7740_remove,
> + .id_table = ov7740_id,
> +};
> +module_i2c_driver(ov7740_i2c_driver);
> +
> +MODULE_DESCRIPTION("The V4L2 driver for Omnivision 7740 sensor");
> +MODULE_AUTHOR("Songjun Wu <songjun.wu@xxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");

--
Regards,

Sakari Ailus
e-mail: sakari.ailus@xxxxxx