Re: [v2,2/2] media: Add a driver for the ov7251 camera sensor

From: jacopo mondi
Date: Fri Mar 23 2018 - 09:40:16 EST


Hi Todor,
thanks for the patch.

When running checkpatch --strict I see a few warning you can easily
close (braces indentation mostly, and one additional empty line at
line 1048).

A few more nits below.

On Fri, Mar 23, 2018 at 12:14:20PM +0800, Todor Tomov wrote:
> The ov7251 sensor is a 1/7.5-Inch B&W VGA (640x480) CMOS Digital Image
> Sensor from Omnivision.
>
> The driver supports the following modes:
> - 640x480 30fps
> - 640x480 60fps
> - 640x480 90fps
>
> Output format is MIPI RAW 10.
>
> The driver supports configuration via user controls for:
> - exposure and gain;
> - horizontal and vertical flip;
> - test pattern.
>
> Signed-off-by: Todor Tomov <todor.tomov@xxxxxxxxxx>
> ---
> drivers/media/i2c/Kconfig | 13 +
> drivers/media/i2c/Makefile | 1 +
> drivers/media/i2c/ov7251.c | 1494 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 1508 insertions(+)
> create mode 100644 drivers/media/i2c/ov7251.c
>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 541f0d28..89aecb3 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -688,6 +688,19 @@ config VIDEO_OV5695
> To compile this driver as a module, choose M here: the
> module will be called ov5695.
>
> +config VIDEO_OV7251
> + tristate "OmniVision OV7251 sensor support"
> + depends on OF
> + depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
> + depends on MEDIA_CAMERA_SUPPORT
> + select V4L2_FWNODE
> + ---help---
> + This is a Video4Linux2 sensor-level driver for the OmniVision
> + OV7251 camera.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ov7251.
> +
> config VIDEO_OV772X
> tristate "OmniVision OV772x sensor support"
> depends on I2C && VIDEO_V4L2
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index ea34aee..c8585b1 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -70,6 +70,7 @@ obj-$(CONFIG_VIDEO_OV5647) += ov5647.o
> obj-$(CONFIG_VIDEO_OV5670) += ov5670.o
> obj-$(CONFIG_VIDEO_OV5695) += ov5695.o
> obj-$(CONFIG_VIDEO_OV6650) += ov6650.o
> +obj-$(CONFIG_VIDEO_OV7251) += ov7251.o
> obj-$(CONFIG_VIDEO_OV7640) += ov7640.o
> obj-$(CONFIG_VIDEO_OV7670) += ov7670.o
> obj-$(CONFIG_VIDEO_OV772X) += ov772x.o
> diff --git a/drivers/media/i2c/ov7251.c b/drivers/media/i2c/ov7251.c
> new file mode 100644
> index 0000000..7b401a9
> --- /dev/null
> +++ b/drivers/media/i2c/ov7251.c
> @@ -0,0 +1,1494 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for the OV7251 camera sensor.
> + *
> + * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2017-2018, Linaro Ltd.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-subdev.h>
> +
> +#define OV7251_VOLTAGE_ANALOG 2800000
> +#define OV7251_VOLTAGE_DIGITAL_CORE 1500000
> +#define OV7251_VOLTAGE_DIGITAL_IO 1800000
> +
> +#define OV7251_SC_MODE_SELECT 0x0100
> +#define OV7251_SC_MODE_SELECT_SW_STANDBY 0x0
> +#define OV7251_SC_MODE_SELECT_STREAMING 0x1
> +
> +#define OV7251_CHIP_ID_HIGH 0x300a
> +#define OV7251_CHIP_ID_HIGH_BYTE 0x77
> +#define OV7251_CHIP_ID_LOW 0x300b
> +#define OV7251_CHIP_ID_LOW_BYTE 0x50
> +#define OV7251_SC_GP_IO_IN1 0x3029
> +#define OV7251_AEC_EXPO_0 0x3500
> +#define OV7251_AEC_EXPO_1 0x3501
> +#define OV7251_AEC_EXPO_2 0x3502
> +#define OV7251_AEC_AGC_ADJ_0 0x350a
> +#define OV7251_AEC_AGC_ADJ_1 0x350b
> +#define OV7251_TIMING_FORMAT1 0x3820
> +#define OV7251_TIMING_FORMAT1_VFLIP BIT(2)
> +#define OV7251_TIMING_FORMAT2 0x3821
> +#define OV7251_TIMING_FORMAT2_MIRROR BIT(2)
> +#define OV7251_PRE_ISP_00 0x5e00
> +#define OV7251_PRE_ISP_00_TEST_PATTERN BIT(7)
> +
> +struct reg_value {
> + u16 reg;
> + u8 val;
> +};
> +
> +struct ov7251_mode_info {
> + u32 width;
> + u32 height;
> + const struct reg_value *data;
> + u32 data_size;
> + u32 pixel_clock;
> + u32 link_freq;
> + u16 exposure_max;
> + u16 exposure_def;
> + struct v4l2_fract timeperframe;
> +};
> +
> +struct ov7251 {
> + struct i2c_client *i2c_client;
> + struct device *dev;
> + struct v4l2_subdev sd;
> + struct media_pad pad;
> + struct v4l2_fwnode_endpoint ep;
> + struct v4l2_mbus_framefmt fmt;
> + struct v4l2_rect crop;
> + struct clk *xclk;
> +
> + struct regulator *io_regulator;
> + struct regulator *core_regulator;
> + struct regulator *analog_regulator;
> +
> + const struct ov7251_mode_info *current_mode;
> +
> + struct v4l2_ctrl_handler ctrls;
> + struct v4l2_ctrl *pixel_clock;
> + struct v4l2_ctrl *link_freq;
> + struct v4l2_ctrl *exposure;
> + struct v4l2_ctrl *gain;
> +
> + /* Cached register values */
> + u8 aec_pk_manual;
> + u8 pre_isp_00;
> + u8 timing_format1;
> + u8 timing_format2;
> +
> + struct mutex power_lock; /* lock to protect power state */
> + bool power_on;
> +
> + struct gpio_desc *enable_gpio;
> +};
> +
> +static inline struct ov7251 *to_ov7251(struct v4l2_subdev *sd)
> +{
> + return container_of(sd, struct ov7251, sd);
> +}
> +
> +static const struct reg_value ov7251_global_init_setting[] = {
> + { 0x0103, 0x01 },
> + { 0x303b, 0x02 },
> +};
> +
> +static const struct reg_value ov7251_setting_vga_30fps[] = {
> + { 0x3005, 0x00 },
> + { 0x3012, 0xc0 },
> + { 0x3013, 0xd2 },
> + { 0x3014, 0x04 },
> + { 0x3016, 0xf0 },
> + { 0x3017, 0xf0 },
> + { 0x3018, 0xf0 },
> + { 0x301a, 0xf0 },
> + { 0x301b, 0xf0 },
> + { 0x301c, 0xf0 },
> + { 0x3023, 0x05 },
> + { 0x3037, 0xf0 },
> + { 0x3098, 0x04 }, /* pll2 pre divider */
> + { 0x3099, 0x28 }, /* pll2 multiplier */
> + { 0x309a, 0x05 }, /* pll2 sys divider */
> + { 0x309b, 0x04 }, /* pll2 adc divider */
> + { 0x309d, 0x00 }, /* pll2 divider */
> + { 0x30b0, 0x0a }, /* pll1 pix divider */
> + { 0x30b1, 0x01 }, /* pll1 divider */
> + { 0x30b3, 0x64 }, /* pll1 multiplier */
> + { 0x30b4, 0x03 }, /* pll1 pre divider */
> + { 0x30b5, 0x05 }, /* pll1 mipi divider */
> + { 0x3106, 0xda },
> + { 0x3503, 0x07 },
> + { 0x3509, 0x10 },
> + { 0x3600, 0x1c },
> + { 0x3602, 0x62 },
> + { 0x3620, 0xb7 },
> + { 0x3622, 0x04 },
> + { 0x3626, 0x21 },
> + { 0x3627, 0x30 },
> + { 0x3630, 0x44 },
> + { 0x3631, 0x35 },
> + { 0x3634, 0x60 },
> + { 0x3636, 0x00 },
> + { 0x3662, 0x01 },
> + { 0x3663, 0x70 },
> + { 0x3664, 0x50 },
> + { 0x3666, 0x0a },
> + { 0x3669, 0x1a },
> + { 0x366a, 0x00 },
> + { 0x366b, 0x50 },
> + { 0x3673, 0x01 },
> + { 0x3674, 0xff },
> + { 0x3675, 0x03 },
> + { 0x3705, 0xc1 },
> + { 0x3709, 0x40 },
> + { 0x373c, 0x08 },
> + { 0x3742, 0x00 },
> + { 0x3757, 0xb3 },
> + { 0x3788, 0x00 },
> + { 0x37a8, 0x01 },
> + { 0x37a9, 0xc0 },
> + { 0x3800, 0x00 },
> + { 0x3801, 0x04 },
> + { 0x3802, 0x00 },
> + { 0x3803, 0x04 },
> + { 0x3804, 0x02 },
> + { 0x3805, 0x8b },
> + { 0x3806, 0x01 },
> + { 0x3807, 0xeb },
> + { 0x3808, 0x02 }, /* width high */
> + { 0x3809, 0x80 }, /* width low */
> + { 0x380a, 0x01 }, /* height high */
> + { 0x380b, 0xe0 }, /* height low */
> + { 0x380c, 0x03 }, /* total horiz timing high */
> + { 0x380d, 0xa0 }, /* total horiz timing low */
> + { 0x380e, 0x06 }, /* total vertical timing high */
> + { 0x380f, 0xbc }, /* total vertical timing low */
> + { 0x3810, 0x00 },
> + { 0x3811, 0x04 },
> + { 0x3812, 0x00 },
> + { 0x3813, 0x05 },
> + { 0x3814, 0x11 },
> + { 0x3815, 0x11 },
> + { 0x3820, 0x40 },
> + { 0x3821, 0x00 },
> + { 0x382f, 0x0e },
> + { 0x3832, 0x00 },
> + { 0x3833, 0x05 },
> + { 0x3834, 0x00 },
> + { 0x3835, 0x0c },
> + { 0x3837, 0x00 },
> + { 0x3b80, 0x00 },
> + { 0x3b81, 0xa5 },
> + { 0x3b82, 0x10 },
> + { 0x3b83, 0x00 },
> + { 0x3b84, 0x08 },
> + { 0x3b85, 0x00 },
> + { 0x3b86, 0x01 },
> + { 0x3b87, 0x00 },
> + { 0x3b88, 0x00 },
> + { 0x3b89, 0x00 },
> + { 0x3b8a, 0x00 },
> + { 0x3b8b, 0x05 },
> + { 0x3b8c, 0x00 },
> + { 0x3b8d, 0x00 },
> + { 0x3b8e, 0x00 },
> + { 0x3b8f, 0x1a },
> + { 0x3b94, 0x05 },
> + { 0x3b95, 0xf2 },
> + { 0x3b96, 0x40 },
> + { 0x3c00, 0x89 },
> + { 0x3c01, 0x63 },
> + { 0x3c02, 0x01 },
> + { 0x3c03, 0x00 },
> + { 0x3c04, 0x00 },
> + { 0x3c05, 0x03 },
> + { 0x3c06, 0x00 },
> + { 0x3c07, 0x06 },
> + { 0x3c0c, 0x01 },
> + { 0x3c0d, 0xd0 },
> + { 0x3c0e, 0x02 },
> + { 0x3c0f, 0x0a },
> + { 0x4001, 0x42 },
> + { 0x4004, 0x04 },
> + { 0x4005, 0x00 },
> + { 0x404e, 0x01 },
> + { 0x4300, 0xff },
> + { 0x4301, 0x00 },
> + { 0x4315, 0x00 },
> + { 0x4501, 0x48 },
> + { 0x4600, 0x00 },
> + { 0x4601, 0x4e },
> + { 0x4801, 0x0f },
> + { 0x4806, 0x0f },
> + { 0x4819, 0xaa },
> + { 0x4823, 0x3e },
> + { 0x4837, 0x19 },
> + { 0x4a0d, 0x00 },
> + { 0x4a47, 0x7f },
> + { 0x4a49, 0xf0 },
> + { 0x4a4b, 0x30 },
> + { 0x5000, 0x85 },
> + { 0x5001, 0x80 },
> +};
> +
> +static const struct reg_value ov7251_setting_vga_60fps[] = {
> + { 0x3005, 0x00 },
> + { 0x3012, 0xc0 },
> + { 0x3013, 0xd2 },
> + { 0x3014, 0x04 },
> + { 0x3016, 0x10 },
> + { 0x3017, 0x00 },
> + { 0x3018, 0x00 },
> + { 0x301a, 0x00 },
> + { 0x301b, 0x00 },
> + { 0x301c, 0x00 },
> + { 0x3023, 0x05 },
> + { 0x3037, 0xf0 },
> + { 0x3098, 0x04 }, /* pll2 pre divider */
> + { 0x3099, 0x28 }, /* pll2 multiplier */
> + { 0x309a, 0x05 }, /* pll2 sys divider */
> + { 0x309b, 0x04 }, /* pll2 adc divider */
> + { 0x309d, 0x00 }, /* pll2 divider */
> + { 0x30b0, 0x0a }, /* pll1 pix divider */
> + { 0x30b1, 0x01 }, /* pll1 divider */
> + { 0x30b3, 0x64 }, /* pll1 multiplier */
> + { 0x30b4, 0x03 }, /* pll1 pre divider */
> + { 0x30b5, 0x05 }, /* pll1 mipi divider */
> + { 0x3106, 0xda },
> + { 0x3503, 0x07 },
> + { 0x3509, 0x10 },
> + { 0x3600, 0x1c },
> + { 0x3602, 0x62 },
> + { 0x3620, 0xb7 },
> + { 0x3622, 0x04 },
> + { 0x3626, 0x21 },
> + { 0x3627, 0x30 },
> + { 0x3630, 0x44 },
> + { 0x3631, 0x35 },
> + { 0x3634, 0x60 },
> + { 0x3636, 0x00 },
> + { 0x3662, 0x01 },
> + { 0x3663, 0x70 },
> + { 0x3664, 0x50 },
> + { 0x3666, 0x0a },
> + { 0x3669, 0x1a },
> + { 0x366a, 0x00 },
> + { 0x366b, 0x50 },
> + { 0x3673, 0x01 },
> + { 0x3674, 0xff },
> + { 0x3675, 0x03 },
> + { 0x3705, 0xc1 },
> + { 0x3709, 0x40 },
> + { 0x373c, 0x08 },
> + { 0x3742, 0x00 },
> + { 0x3757, 0xb3 },
> + { 0x3788, 0x00 },
> + { 0x37a8, 0x01 },
> + { 0x37a9, 0xc0 },
> + { 0x3800, 0x00 },
> + { 0x3801, 0x04 },
> + { 0x3802, 0x00 },
> + { 0x3803, 0x04 },
> + { 0x3804, 0x02 },
> + { 0x3805, 0x8b },
> + { 0x3806, 0x01 },
> + { 0x3807, 0xeb },
> + { 0x3808, 0x02 }, /* width high */
> + { 0x3809, 0x80 }, /* width low */
> + { 0x380a, 0x01 }, /* height high */
> + { 0x380b, 0xe0 }, /* height low */
> + { 0x380c, 0x03 }, /* total horiz timing high */
> + { 0x380d, 0xa0 }, /* total horiz timing low */
> + { 0x380e, 0x03 }, /* total vertical timing high */
> + { 0x380f, 0x5c }, /* total vertical timing low */
> + { 0x3810, 0x00 },
> + { 0x3811, 0x04 },
> + { 0x3812, 0x00 },
> + { 0x3813, 0x05 },
> + { 0x3814, 0x11 },
> + { 0x3815, 0x11 },
> + { 0x3820, 0x40 },
> + { 0x3821, 0x00 },
> + { 0x382f, 0x0e },
> + { 0x3832, 0x00 },
> + { 0x3833, 0x05 },
> + { 0x3834, 0x00 },
> + { 0x3835, 0x0c },
> + { 0x3837, 0x00 },
> + { 0x3b80, 0x00 },
> + { 0x3b81, 0xa5 },
> + { 0x3b82, 0x10 },
> + { 0x3b83, 0x00 },
> + { 0x3b84, 0x08 },
> + { 0x3b85, 0x00 },
> + { 0x3b86, 0x01 },
> + { 0x3b87, 0x00 },
> + { 0x3b88, 0x00 },
> + { 0x3b89, 0x00 },
> + { 0x3b8a, 0x00 },
> + { 0x3b8b, 0x05 },
> + { 0x3b8c, 0x00 },
> + { 0x3b8d, 0x00 },
> + { 0x3b8e, 0x00 },
> + { 0x3b8f, 0x1a },
> + { 0x3b94, 0x05 },
> + { 0x3b95, 0xf2 },
> + { 0x3b96, 0x40 },
> + { 0x3c00, 0x89 },
> + { 0x3c01, 0x63 },
> + { 0x3c02, 0x01 },
> + { 0x3c03, 0x00 },
> + { 0x3c04, 0x00 },
> + { 0x3c05, 0x03 },
> + { 0x3c06, 0x00 },
> + { 0x3c07, 0x06 },
> + { 0x3c0c, 0x01 },
> + { 0x3c0d, 0xd0 },
> + { 0x3c0e, 0x02 },
> + { 0x3c0f, 0x0a },
> + { 0x4001, 0x42 },
> + { 0x4004, 0x04 },
> + { 0x4005, 0x00 },
> + { 0x404e, 0x01 },
> + { 0x4300, 0xff },
> + { 0x4301, 0x00 },
> + { 0x4315, 0x00 },
> + { 0x4501, 0x48 },
> + { 0x4600, 0x00 },
> + { 0x4601, 0x4e },
> + { 0x4801, 0x0f },
> + { 0x4806, 0x0f },
> + { 0x4819, 0xaa },
> + { 0x4823, 0x3e },
> + { 0x4837, 0x19 },
> + { 0x4a0d, 0x00 },
> + { 0x4a47, 0x7f },
> + { 0x4a49, 0xf0 },
> + { 0x4a4b, 0x30 },
> + { 0x5000, 0x85 },
> + { 0x5001, 0x80 },
> +};
> +
> +static const struct reg_value ov7251_setting_vga_90fps[] = {
> + { 0x3005, 0x00 },
> + { 0x3012, 0xc0 },
> + { 0x3013, 0xd2 },
> + { 0x3014, 0x04 },
> + { 0x3016, 0x10 },
> + { 0x3017, 0x00 },
> + { 0x3018, 0x00 },
> + { 0x301a, 0x00 },
> + { 0x301b, 0x00 },
> + { 0x301c, 0x00 },
> + { 0x3023, 0x05 },
> + { 0x3037, 0xf0 },
> + { 0x3098, 0x04 }, /* pll2 pre divider */
> + { 0x3099, 0x28 }, /* pll2 multiplier */
> + { 0x309a, 0x05 }, /* pll2 sys divider */
> + { 0x309b, 0x04 }, /* pll2 adc divider */
> + { 0x309d, 0x00 }, /* pll2 divider */
> + { 0x30b0, 0x0a }, /* pll1 pix divider */
> + { 0x30b1, 0x01 }, /* pll1 divider */
> + { 0x30b3, 0x64 }, /* pll1 multiplier */
> + { 0x30b4, 0x03 }, /* pll1 pre divider */
> + { 0x30b5, 0x05 }, /* pll1 mipi divider */
> + { 0x3106, 0xda },
> + { 0x3503, 0x07 },
> + { 0x3509, 0x10 },
> + { 0x3600, 0x1c },
> + { 0x3602, 0x62 },
> + { 0x3620, 0xb7 },
> + { 0x3622, 0x04 },
> + { 0x3626, 0x21 },
> + { 0x3627, 0x30 },
> + { 0x3630, 0x44 },
> + { 0x3631, 0x35 },
> + { 0x3634, 0x60 },
> + { 0x3636, 0x00 },
> + { 0x3662, 0x01 },
> + { 0x3663, 0x70 },
> + { 0x3664, 0x50 },
> + { 0x3666, 0x0a },
> + { 0x3669, 0x1a },
> + { 0x366a, 0x00 },
> + { 0x366b, 0x50 },
> + { 0x3673, 0x01 },
> + { 0x3674, 0xff },
> + { 0x3675, 0x03 },
> + { 0x3705, 0xc1 },
> + { 0x3709, 0x40 },
> + { 0x373c, 0x08 },
> + { 0x3742, 0x00 },
> + { 0x3757, 0xb3 },
> + { 0x3788, 0x00 },
> + { 0x37a8, 0x01 },
> + { 0x37a9, 0xc0 },
> + { 0x3800, 0x00 },
> + { 0x3801, 0x04 },
> + { 0x3802, 0x00 },
> + { 0x3803, 0x04 },
> + { 0x3804, 0x02 },
> + { 0x3805, 0x8b },
> + { 0x3806, 0x01 },
> + { 0x3807, 0xeb },
> + { 0x3808, 0x02 }, /* width high */
> + { 0x3809, 0x80 }, /* width low */
> + { 0x380a, 0x01 }, /* height high */
> + { 0x380b, 0xe0 }, /* height low */
> + { 0x380c, 0x03 }, /* total horiz timing high */
> + { 0x380d, 0xa0 }, /* total horiz timing low */
> + { 0x380e, 0x02 }, /* total vertical timing high */
> + { 0x380f, 0x3c }, /* total vertical timing low */
> + { 0x3810, 0x00 },
> + { 0x3811, 0x04 },
> + { 0x3812, 0x00 },
> + { 0x3813, 0x05 },
> + { 0x3814, 0x11 },
> + { 0x3815, 0x11 },
> + { 0x3820, 0x40 },
> + { 0x3821, 0x00 },
> + { 0x382f, 0x0e },
> + { 0x3832, 0x00 },
> + { 0x3833, 0x05 },
> + { 0x3834, 0x00 },
> + { 0x3835, 0x0c },
> + { 0x3837, 0x00 },
> + { 0x3b80, 0x00 },
> + { 0x3b81, 0xa5 },
> + { 0x3b82, 0x10 },
> + { 0x3b83, 0x00 },
> + { 0x3b84, 0x08 },
> + { 0x3b85, 0x00 },
> + { 0x3b86, 0x01 },
> + { 0x3b87, 0x00 },
> + { 0x3b88, 0x00 },
> + { 0x3b89, 0x00 },
> + { 0x3b8a, 0x00 },
> + { 0x3b8b, 0x05 },
> + { 0x3b8c, 0x00 },
> + { 0x3b8d, 0x00 },
> + { 0x3b8e, 0x00 },
> + { 0x3b8f, 0x1a },
> + { 0x3b94, 0x05 },
> + { 0x3b95, 0xf2 },
> + { 0x3b96, 0x40 },
> + { 0x3c00, 0x89 },
> + { 0x3c01, 0x63 },
> + { 0x3c02, 0x01 },
> + { 0x3c03, 0x00 },
> + { 0x3c04, 0x00 },
> + { 0x3c05, 0x03 },
> + { 0x3c06, 0x00 },
> + { 0x3c07, 0x06 },
> + { 0x3c0c, 0x01 },
> + { 0x3c0d, 0xd0 },
> + { 0x3c0e, 0x02 },
> + { 0x3c0f, 0x0a },
> + { 0x4001, 0x42 },
> + { 0x4004, 0x04 },
> + { 0x4005, 0x00 },
> + { 0x404e, 0x01 },
> + { 0x4300, 0xff },
> + { 0x4301, 0x00 },
> + { 0x4315, 0x00 },
> + { 0x4501, 0x48 },
> + { 0x4600, 0x00 },
> + { 0x4601, 0x4e },
> + { 0x4801, 0x0f },
> + { 0x4806, 0x0f },
> + { 0x4819, 0xaa },
> + { 0x4823, 0x3e },
> + { 0x4837, 0x19 },
> + { 0x4a0d, 0x00 },
> + { 0x4a47, 0x7f },
> + { 0x4a49, 0xf0 },
> + { 0x4a4b, 0x30 },
> + { 0x5000, 0x85 },
> + { 0x5001, 0x80 },
> +};
> +
> +static const s64 link_freq[] = {
> + 240000000,
> +};
> +
> +static const struct ov7251_mode_info ov7251_mode_info_data[] = {
> + {
> + .width = 640,
> + .height = 480,
> + .data = ov7251_setting_vga_30fps,
> + .data_size = ARRAY_SIZE(ov7251_setting_vga_30fps),
> + .pixel_clock = 48000000,
> + .link_freq = 0, /* an index in link_freq[] */
> + .exposure_max = 1704,
> + .exposure_def = 504,
> + .timeperframe = {
> + .numerator = 100,
> + .denominator = 3000
> + }
> + },
> + {
> + .width = 640,
> + .height = 480,
> + .data = ov7251_setting_vga_60fps,
> + .data_size = ARRAY_SIZE(ov7251_setting_vga_60fps),
> + .pixel_clock = 48000000,
> + .link_freq = 0, /* an index in link_freq[] */
> + .exposure_max = 840,
> + .exposure_def = 504,
> + .timeperframe = {
> + .numerator = 100,
> + .denominator = 6014
> + }
> + },
> + {
> + .width = 640,
> + .height = 480,
> + .data = ov7251_setting_vga_90fps,
> + .data_size = ARRAY_SIZE(ov7251_setting_vga_90fps),
> + .pixel_clock = 48000000,
> + .link_freq = 0, /* an index in link_freq[] */
> + .exposure_max = 552,
> + .exposure_def = 504,
> + .timeperframe = {
> + .numerator = 100,
> + .denominator = 9043
> + }
> + },
> +};
> +
> +static int ov7251_regulators_enable(struct ov7251 *ov7251)
> +{
> + int ret;
> +
> + ret = regulator_enable(ov7251->io_regulator);
> + if (ret < 0) {
> + dev_err(ov7251->dev, "set io voltage failed\n");
> + return ret;
> + }
> +
> + ret = regulator_enable(ov7251->analog_regulator);
> + if (ret) {
> + dev_err(ov7251->dev, "set analog voltage failed\n");
> + goto err_disable_io;
> + }
> +
> + ret = regulator_enable(ov7251->core_regulator);
> + if (ret) {
> + dev_err(ov7251->dev, "set core voltage failed\n");
> + goto err_disable_analog;
> + }
> +
> + return 0;
> +
> +err_disable_analog:
> + regulator_disable(ov7251->analog_regulator);
> +err_disable_io:
> + regulator_disable(ov7251->io_regulator);
> +
> + return ret;
> +}
> +
> +static void ov7251_regulators_disable(struct ov7251 *ov7251)
> +{
> + int ret;
> +
> + ret = regulator_disable(ov7251->core_regulator);
> + if (ret < 0)
> + dev_err(ov7251->dev, "core regulator disable failed\n");
> +
> + ret = regulator_disable(ov7251->analog_regulator);
> + if (ret < 0)
> + dev_err(ov7251->dev, "analog regulator disable failed\n");
> +
> + ret = regulator_disable(ov7251->io_regulator);
> + if (ret < 0)
> + dev_err(ov7251->dev, "io regulator disable failed\n");
> +}
> +
> +static int ov7251_write_reg(struct ov7251 *ov7251, u16 reg, u8 val)
> +{
> + u8 regbuf[3];
> + int ret;
> +
> + regbuf[0] = reg >> 8;
> + regbuf[1] = reg & 0xff;
> + regbuf[2] = val;
> +
> + ret = i2c_master_send(ov7251->i2c_client, regbuf, 3);
> + if (ret < 0) {
> + dev_err(ov7251->dev, "%s: write reg error %d: reg=%x, val=%x\n",
> + __func__, ret, reg, val);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ov7251_read_reg(struct ov7251 *ov7251, u16 reg, u8 *val)
> +{
> + u8 regbuf[2];
> + int ret;
> +
> + regbuf[0] = reg >> 8;
> + regbuf[1] = reg & 0xff;
> +
> + ret = i2c_master_send(ov7251->i2c_client, regbuf, 2);
> + if (ret < 0) {
> + dev_err(ov7251->dev, "%s: write reg error %d: reg=%x\n",
> + __func__, ret, reg);
> + return ret;
> + }
> +
> + ret = i2c_master_recv(ov7251->i2c_client, val, 1);
> + if (ret < 0) {
> + dev_err(ov7251->dev, "%s: read reg error %d: reg=%x\n",
> + __func__, ret, reg);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ov7251_set_exposure(struct ov7251 *ov7251, s32 exposure)
> +{
> + int ret;
> +
> + ret = ov7251_write_reg(ov7251, OV7251_AEC_EXPO_0,
> + (exposure & 0xf000) >> 12);
> + if (ret < 0)
> + return ret;
> +
> + ret = ov7251_write_reg(ov7251, OV7251_AEC_EXPO_1,
> + (exposure & 0x0ff0) >> 4);
> + if (ret < 0)
> + return ret;
> +
> + return ov7251_write_reg(ov7251, OV7251_AEC_EXPO_2,
> + (exposure & 0x000f) << 4);
> +}
> +
> +static int ov7251_set_gain(struct ov7251 *ov7251, s32 gain)
> +{
> + int ret;
> +
> + ret = ov7251_write_reg(ov7251, OV7251_AEC_AGC_ADJ_0,
> + (gain & 0x0300) >> 8);
> + if (ret < 0)
> + return ret;
> +
> + return ov7251_write_reg(ov7251, OV7251_AEC_AGC_ADJ_1, gain & 0xff);
> +}
> +
> +static int ov7251_set_register_array(struct ov7251 *ov7251,
> + const struct reg_value *settings,
> + unsigned int num_settings)
> +{
> + unsigned int i;
> + int ret;
> +
> + for (i = 0; i < num_settings; ++i, ++settings) {
> + ret = ov7251_write_reg(ov7251, settings->reg, settings->val);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ov7251_set_power_on(struct ov7251 *ov7251)
> +{
> + int ret;
> +
> + ret = ov7251_regulators_enable(ov7251);
> + if (ret < 0)
> + return ret;
> +
> + ret = clk_prepare_enable(ov7251->xclk);
> + if (ret < 0) {
> + dev_err(ov7251->dev, "clk prepare enable failed\n");
> + ov7251_regulators_disable(ov7251);
> + return ret;
> + }
> +
> + gpiod_set_value_cansleep(ov7251->enable_gpio, 1);
> +
> + usleep_range(3000, 4000); /* 65536 / 24MHz = 2.73ms */
> +
> + return 0;
> +}
> +
> +static void ov7251_set_power_off(struct ov7251 *ov7251)
> +{
> + clk_disable_unprepare(ov7251->xclk);
> + gpiod_set_value_cansleep(ov7251->enable_gpio, 0);
> + ov7251_regulators_disable(ov7251);
> +}
> +
> +static int ov7251_s_power(struct v4l2_subdev *sd, int on)
> +{
> + struct ov7251 *ov7251 = to_ov7251(sd);
> + int ret = 0;
> +
> + mutex_lock(&ov7251->power_lock);
> +
> + /*
> + * If the power state is modified from 0 to 1 or from 1 to 0,
> + * update the power state.
> + */
> + if (ov7251->power_on == !on) {

if (ov7251->power_on == !!on) {
mutex_unlock(&ov7251->power_lock);
return 0;
}

And you can save one indentation level and remove ret initialization.


> + if (on) {
> + ret = ov7251_set_power_on(ov7251);
> + if (ret < 0)
> + goto exit;
> +
> + ret = ov7251_set_register_array(ov7251,
> + ov7251_global_init_setting,
> + ARRAY_SIZE(ov7251_global_init_setting));
> + if (ret < 0) {
> + dev_err(ov7251->dev,
> + "could not set init registers\n");
> + ov7251_set_power_off(ov7251);
> + goto exit;
> + }
> +
> + ov7251->power_on = true;
> + } else {
> + ov7251_set_power_off(ov7251);
> + ov7251->power_on = false;
> + }
> + }
> +
> +exit:
> + mutex_unlock(&ov7251->power_lock);
> +
> + return ret;
> +}
> +
> +static int ov7251_set_hflip(struct ov7251 *ov7251, s32 value)
> +{
> + u8 val = ov7251->timing_format2;
> + int ret;
> +
> + if (value)
> + val |= OV7251_TIMING_FORMAT2_MIRROR;
> + else
> + val &= ~OV7251_TIMING_FORMAT2_MIRROR;
> +
> + ret = ov7251_write_reg(ov7251, OV7251_TIMING_FORMAT2, val);
> + if (!ret)
> + ov7251->timing_format2 = val;
> +
> + return ret;
> +}
> +
> +static int ov7251_set_vflip(struct ov7251 *ov7251, s32 value)
> +{
> + u8 val = ov7251->timing_format1;
> + int ret;
> +
> + if (value)
> + val |= OV7251_TIMING_FORMAT1_VFLIP;
> + else
> + val &= ~OV7251_TIMING_FORMAT1_VFLIP;
> +
> + ret = ov7251_write_reg(ov7251, OV7251_TIMING_FORMAT1, val);
> + if (!ret)
> + ov7251->timing_format1 = val;
> +
> + return ret;
> +}
> +
> +static int ov7251_set_test_pattern(struct ov7251 *ov7251, s32 value)
> +{
> + u8 val = ov7251->pre_isp_00;
> + int ret;
> +
> + if (value)
> + val |= OV7251_PRE_ISP_00_TEST_PATTERN;
> + else
> + val &= ~OV7251_PRE_ISP_00_TEST_PATTERN;
> +
> + ret = ov7251_write_reg(ov7251, OV7251_PRE_ISP_00, val);
> + if (!ret)
> + ov7251->pre_isp_00 = val;
> +
> + return ret;
> +}
> +
> +static const char * const ov7251_test_pattern_menu[] = {
> + "Disabled",
> + "Vertical Pattern Bars",
> +};
> +
> +static int ov7251_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct ov7251 *ov7251 = container_of(ctrl->handler,
> + struct ov7251, ctrls);
> + int ret;
> +
> + mutex_lock(&ov7251->power_lock);
> + if (!ov7251->power_on) {
> + mutex_unlock(&ov7251->power_lock);
> + return 0;
> + }
> +
> + switch (ctrl->id) {
> + case V4L2_CID_EXPOSURE:
> + ret = ov7251_set_exposure(ov7251, ctrl->val);
> + break;
> + case V4L2_CID_GAIN:
> + ret = ov7251_set_gain(ov7251, ctrl->val);
> + break;
> + case V4L2_CID_TEST_PATTERN:
> + ret = ov7251_set_test_pattern(ov7251, ctrl->val);
> + break;
> + case V4L2_CID_HFLIP:
> + ret = ov7251_set_hflip(ov7251, ctrl->val);
> + break;
> + case V4L2_CID_VFLIP:
> + ret = ov7251_set_vflip(ov7251, ctrl->val);
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + mutex_unlock(&ov7251->power_lock);
> +
> + return ret;
> +}
> +
> +static const struct v4l2_ctrl_ops ov7251_ctrl_ops = {
> + .s_ctrl = ov7251_s_ctrl,
> +};
> +
> +static int ov7251_enum_mbus_code(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_mbus_code_enum *code)
> +{
> + if (code->index > 0)
> + return -EINVAL;
> +
> + code->code = MEDIA_BUS_FMT_SBGGR10_1X10;
> +
> + return 0;
> +}
> +
> +static int ov7251_enum_frame_size(struct v4l2_subdev *subdev,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_frame_size_enum *fse)
> +{

Shouldn't you check for (pad != 0) in all subdev pad operations?
I see other driver with a single pad doing this...


> + if (fse->code != MEDIA_BUS_FMT_SBGGR10_1X10)
> + return -EINVAL;
> +
> + if (fse->index >= ARRAY_SIZE(ov7251_mode_info_data))
> + return -EINVAL;
> +
> + fse->min_width = ov7251_mode_info_data[fse->index].width;
> + fse->max_width = ov7251_mode_info_data[fse->index].width;
> + fse->min_height = ov7251_mode_info_data[fse->index].height;
> + fse->max_height = ov7251_mode_info_data[fse->index].height;
> +
> + return 0;
> +}
> +
> +static int ov7251_enum_frame_ival(struct v4l2_subdev *subdev,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_frame_interval_enum *fie)
> +{
> + int index = fie->index;
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(ov7251_mode_info_data); i++) {
> + if (fie->width != ov7251_mode_info_data[i].width ||
> + fie->height != ov7251_mode_info_data[i].height)
> + continue;
> +
> + if (index-- == 0) {
> + fie->interval = ov7251_mode_info_data[i].timeperframe;
> + return 0;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +static struct v4l2_mbus_framefmt *
> +__ov7251_get_pad_format(struct ov7251 *ov7251,
> + struct v4l2_subdev_pad_config *cfg,
> + unsigned int pad,
> + enum v4l2_subdev_format_whence which)
> +{
> + switch (which) {
> + case V4L2_SUBDEV_FORMAT_TRY:
> + return v4l2_subdev_get_try_format(&ov7251->sd, cfg, pad);
> + case V4L2_SUBDEV_FORMAT_ACTIVE:
> + return &ov7251->fmt;
> + default:
> + return NULL;
> + }
> +}
> +
> +static int ov7251_get_format(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_format *format)
> +{
> + struct ov7251 *ov7251 = to_ov7251(sd);
> +
> + format->format = *__ov7251_get_pad_format(ov7251, cfg, format->pad,
> + format->which);
> + return 0;
> +}
> +
> +static struct v4l2_rect *
> +__ov7251_get_pad_crop(struct ov7251 *ov7251, struct v4l2_subdev_pad_config *cfg,
> + unsigned int pad, enum v4l2_subdev_format_whence which)
> +{
> + switch (which) {
> + case V4L2_SUBDEV_FORMAT_TRY:
> + return v4l2_subdev_get_try_crop(&ov7251->sd, cfg, pad);
> + case V4L2_SUBDEV_FORMAT_ACTIVE:
> + return &ov7251->crop;
> + default:
> + return NULL;
> + }
> +}
> +
> +#define TIMEPERFRAME_AVG_FPS(t) \
> + (((t).denominator + ((t).numerator >> 1)) / (t).numerator)
> +
> +static const struct ov7251_mode_info *
> +ov7251_find_mode_by_ival(struct ov7251 *ov7251, struct v4l2_fract *timeperframe)
> +{
> + const struct ov7251_mode_info *mode = ov7251->current_mode;
> + int fps_req = TIMEPERFRAME_AVG_FPS(*timeperframe);
> + unsigned int max_dist_match = (unsigned int) -1;
> + int i, n = 0;
> +
> + for (i = 0; i < ARRAY_SIZE(ov7251_mode_info_data); i++) {
> + unsigned int dist;
> + int fps_tmp;
> +
> + if (mode->width != ov7251_mode_info_data[i].width ||
> + mode->height != ov7251_mode_info_data[i].height)
> + continue;
> +
> + fps_tmp = TIMEPERFRAME_AVG_FPS(
> + ov7251_mode_info_data[i].timeperframe);
> +
> + dist = abs(fps_req - fps_tmp);
> +
> + if (dist < max_dist_match) {
> + n = i;
> + max_dist_match = dist;
> + }
> + }
> +
> + return &ov7251_mode_info_data[n];
> +}
> +
> +static int ov7251_set_format(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_format *format)
> +{
> + struct ov7251 *ov7251 = to_ov7251(sd);
> + struct v4l2_mbus_framefmt *__format;
> + struct v4l2_rect *__crop;
> + const struct ov7251_mode_info *new_mode;
> + int ret;
> +
> + __crop = __ov7251_get_pad_crop(ov7251, cfg, format->pad,
> + format->which);
> +
> + new_mode = v4l2_find_nearest_size(ov7251_mode_info_data,
> + width, height,
> + format->format.width, format->format.height);
> +
> + __crop->width = new_mode->width;
> + __crop->height = new_mode->height;
> +
> + if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
> + ret = v4l2_ctrl_s_ctrl_int64(ov7251->pixel_clock,
> + new_mode->pixel_clock);
> + if (ret < 0)
> + return ret;
> +
> + ret = v4l2_ctrl_s_ctrl(ov7251->link_freq,
> + new_mode->link_freq);
> + if (ret < 0)
> + return ret;
> +
> + ret = v4l2_ctrl_modify_range(ov7251->exposure,
> + 1, new_mode->exposure_max,
> + 1, new_mode->exposure_def);
> + if (ret < 0)
> + return ret;
> +
> + ret = v4l2_ctrl_s_ctrl(ov7251->exposure,
> + new_mode->exposure_def);
> + if (ret < 0)
> + return ret;
> +
> +
> + ret = v4l2_ctrl_s_ctrl(ov7251->gain, 16);
> + if (ret < 0)
> + return ret;
> +
> + ov7251->current_mode = new_mode;
> + }
> +
> + __format = __ov7251_get_pad_format(ov7251, cfg, format->pad,
> + format->which);
> + __format->width = __crop->width;
> + __format->height = __crop->height;
> + __format->code = MEDIA_BUS_FMT_SBGGR10_1X10;
> + __format->field = V4L2_FIELD_NONE;
> + __format->colorspace = V4L2_COLORSPACE_SRGB;
> + __format->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(__format->colorspace);
> + __format->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true,
> + __format->colorspace, __format->ycbcr_enc);
> + __format->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(__format->colorspace);

Oh nice, I didn't know about the V4L2_MAP macros ;)

> +
> + format->format = *__format;
> +
> + return 0;
> +}
> +
> +static int ov7251_entity_init_cfg(struct v4l2_subdev *subdev,
> + 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 = 640;
> + fmt.format.height = 480;
> +
> + ov7251_set_format(subdev, cfg, &fmt);
> +
> + return 0;
> +}
> +
> +static int ov7251_get_selection(struct v4l2_subdev *sd,
> + struct v4l2_subdev_pad_config *cfg,
> + struct v4l2_subdev_selection *sel)
> +{
> + struct ov7251 *ov7251 = to_ov7251(sd);
> +
> + if (sel->target != V4L2_SEL_TGT_CROP)
> + return -EINVAL;
> +
> + sel->r = *__ov7251_get_pad_crop(ov7251, cfg, sel->pad,
> + sel->which);
> + return 0;
> +}
> +
> +static int ov7251_s_stream(struct v4l2_subdev *subdev, int enable)
> +{
> + struct ov7251 *ov7251 = to_ov7251(subdev);
> + int ret;
> +
> + if (enable) {
> + ret = ov7251_set_register_array(ov7251,
> + ov7251->current_mode->data,
> + ov7251->current_mode->data_size);
> + if (ret < 0) {
> + dev_err(ov7251->dev, "could not set mode %dx%d\n",
> + ov7251->current_mode->width,
> + ov7251->current_mode->height);
> + return ret;
> + }
> + ret = v4l2_ctrl_handler_setup(&ov7251->ctrls);
> + if (ret < 0) {
> + dev_err(ov7251->dev, "could not sync v4l2 controls\n");
> + return ret;
> + }
> + ret = ov7251_write_reg(ov7251, OV7251_SC_MODE_SELECT,
> + OV7251_SC_MODE_SELECT_STREAMING);
> + if (ret < 0)
> + return ret;
> + } else {
> + ret = ov7251_write_reg(ov7251, OV7251_SC_MODE_SELECT,
> + OV7251_SC_MODE_SELECT_SW_STANDBY);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ov7251_get_frame_interval(struct v4l2_subdev *subdev,
> + struct v4l2_subdev_frame_interval *fi)
> +{
> + struct ov7251 *ov7251 = to_ov7251(subdev);
> +
> + fi->interval = ov7251->current_mode->timeperframe;
> +
> + return 0;
> +}
> +
> +static int ov7251_set_frame_interval(struct v4l2_subdev *subdev,
> + struct v4l2_subdev_frame_interval *fi)
> +{
> + struct ov7251 *ov7251 = to_ov7251(subdev);
> + const struct ov7251_mode_info *new_mode;
> +
> + new_mode = ov7251_find_mode_by_ival(ov7251, &fi->interval);
> +
> + if (new_mode != ov7251->current_mode) {
> + int ret;
> +
> + ret = v4l2_ctrl_s_ctrl_int64(ov7251->pixel_clock,
> + new_mode->pixel_clock);
> + if (ret < 0)
> + return ret;
> +
> + ret = v4l2_ctrl_s_ctrl(ov7251->link_freq,
> + new_mode->link_freq);
> + if (ret < 0)
> + return ret;
> +
> + ret = v4l2_ctrl_modify_range(ov7251->exposure,
> + 1, new_mode->exposure_max,
> + 1, new_mode->exposure_def);
> + if (ret < 0)
> + return ret;
> +
> + ret = v4l2_ctrl_s_ctrl(ov7251->exposure,
> + new_mode->exposure_def);
> + if (ret < 0)
> + return ret;
> +
> + ret = v4l2_ctrl_s_ctrl(ov7251->gain, 16);
> + if (ret < 0)
> + return ret;
> +
> + ov7251->current_mode = new_mode;
> + }
> +
> + fi->interval = ov7251->current_mode->timeperframe;
> +
> + return 0;
> +}
> +
> +static const struct v4l2_subdev_core_ops ov7251_core_ops = {
> + .s_power = ov7251_s_power,
> +};
> +
> +static const struct v4l2_subdev_video_ops ov7251_video_ops = {
> + .s_stream = ov7251_s_stream,
> + .g_frame_interval = ov7251_get_frame_interval,
> + .s_frame_interval = ov7251_set_frame_interval,
> +};
> +
> +static const struct v4l2_subdev_pad_ops ov7251_subdev_pad_ops = {
> + .init_cfg = ov7251_entity_init_cfg,
> + .enum_mbus_code = ov7251_enum_mbus_code,
> + .enum_frame_size = ov7251_enum_frame_size,
> + .enum_frame_interval = ov7251_enum_frame_ival,
> + .get_fmt = ov7251_get_format,
> + .set_fmt = ov7251_set_format,
> + .get_selection = ov7251_get_selection,
> +};
> +
> +static const struct v4l2_subdev_ops ov7251_subdev_ops = {
> + .core = &ov7251_core_ops,
> + .video = &ov7251_video_ops,
> + .pad = &ov7251_subdev_pad_ops,
> +};
> +
> +static int ov7251_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = &client->dev;
> + struct fwnode_handle *endpoint;
> + struct ov7251 *ov7251;
> + u8 chip_id_high, chip_id_low, chip_rev;
> + u32 xclk_freq;
> + int ret;
> +
> + ov7251 = devm_kzalloc(dev, sizeof(struct ov7251), GFP_KERNEL);
> + if (!ov7251)
> + return -ENOMEM;
> +
> + ov7251->i2c_client = client;
> + ov7251->dev = dev;
> +
> + endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
> + if (!endpoint) {
> + dev_err(dev, "endpoint node not found\n");
> + return -EINVAL;
> + }
> +
> + ret = v4l2_fwnode_endpoint_parse(endpoint, &ov7251->ep);
> + fwnode_handle_put(endpoint);
> + if (ret < 0) {
> + dev_err(dev, "parsing endpoint node failed\n");
> + return ret;
> + }
> +
> + if (ov7251->ep.bus_type != V4L2_MBUS_CSI2) {
> + dev_err(dev, "invalid bus type (%u), must be CSI2 (%u)\n",
> + ov7251->ep.bus_type, V4L2_MBUS_CSI2);
> + return -EINVAL;
> + }
> +
> + /* get system clock (xclk) */
> + ov7251->xclk = devm_clk_get(dev, "xclk");
> + if (IS_ERR(ov7251->xclk)) {
> + dev_err(dev, "could not get xclk");
> + return PTR_ERR(ov7251->xclk);
> + }
> +
> + ret = of_property_read_u32(dev->of_node, "clock-frequency", &xclk_freq);
> + if (ret) {
> + dev_err(dev, "could not get xclk frequency\n");
> + return ret;
> + }
> +
> + /* external clock must be 24MHz, allow 1% tolerance */
> + if (xclk_freq < 23760000 || xclk_freq > 24240000) {
> + dev_err(dev, "external clock frequency %u is not supported\n",
> + xclk_freq);
> + return -EINVAL;
> + }
> +
> + ret = clk_set_rate(ov7251->xclk, xclk_freq);
> + if (ret) {
> + dev_err(dev, "could not set xclk frequency\n");
> + return ret;
> + }
> +
> + ov7251->io_regulator = devm_regulator_get(dev, "vdddo");
> + if (IS_ERR(ov7251->io_regulator)) {
> + dev_err(dev, "cannot get io regulator\n");
> + return PTR_ERR(ov7251->io_regulator);
> + }
> +
> + ret = regulator_set_voltage(ov7251->io_regulator,
> + OV7251_VOLTAGE_DIGITAL_IO,
> + OV7251_VOLTAGE_DIGITAL_IO);
> + if (ret < 0) {
> + dev_err(dev, "cannot set io voltage\n");
> + return ret;
> + }
> +
> + ov7251->core_regulator = devm_regulator_get(dev, "vddd");
> + if (IS_ERR(ov7251->core_regulator)) {
> + dev_err(dev, "cannot get core regulator\n");
> + return PTR_ERR(ov7251->core_regulator);
> + }
> +
> + ret = regulator_set_voltage(ov7251->core_regulator,
> + OV7251_VOLTAGE_DIGITAL_CORE,
> + OV7251_VOLTAGE_DIGITAL_CORE);
> + if (ret < 0) {
> + dev_err(dev, "cannot set core voltage\n");
> + return ret;
> + }
> +
> + ov7251->analog_regulator = devm_regulator_get(dev, "vdda");
> + if (IS_ERR(ov7251->analog_regulator)) {
> + dev_err(dev, "cannot get analog regulator\n");
> + return PTR_ERR(ov7251->analog_regulator);
> + }
> +
> + ret = regulator_set_voltage(ov7251->analog_regulator,
> + OV7251_VOLTAGE_ANALOG,
> + OV7251_VOLTAGE_ANALOG);
> + if (ret < 0) {
> + dev_err(dev, "cannot set analog voltage\n");
> + return ret;
> + }
> +
> + ov7251->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
> + if (IS_ERR(ov7251->enable_gpio)) {
> + dev_err(dev, "cannot get enable gpio\n");
> + return PTR_ERR(ov7251->enable_gpio);
> + }
> +
> + mutex_init(&ov7251->power_lock);
> +
> + v4l2_ctrl_handler_init(&ov7251->ctrls, 7);
> + v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
> + V4L2_CID_HFLIP, 0, 1, 1, 0);
> + v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
> + V4L2_CID_VFLIP, 0, 1, 1, 0);
> + ov7251->exposure = v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
> + V4L2_CID_EXPOSURE, 1, 32, 1, 32);
> + ov7251->gain = v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
> + V4L2_CID_GAIN, 16, 1023, 1, 16);
> + v4l2_ctrl_new_std_menu_items(&ov7251->ctrls, &ov7251_ctrl_ops,
> + V4L2_CID_TEST_PATTERN,
> + ARRAY_SIZE(ov7251_test_pattern_menu) - 1,
> + 0, 0, ov7251_test_pattern_menu);
> + ov7251->pixel_clock = v4l2_ctrl_new_std(&ov7251->ctrls,
> + &ov7251_ctrl_ops,
> + V4L2_CID_PIXEL_RATE,
> + 1, INT_MAX, 1, 1);
> + ov7251->link_freq = v4l2_ctrl_new_int_menu(&ov7251->ctrls,
> + &ov7251_ctrl_ops,
> + V4L2_CID_LINK_FREQ,
> + ARRAY_SIZE(link_freq) - 1,
> + 0, link_freq);
> + if (ov7251->link_freq)
> + ov7251->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> + ov7251->sd.ctrl_handler = &ov7251->ctrls;
> +
> + if (ov7251->ctrls.error) {
> + dev_err(dev, "%s: control initialization error %d\n",
> + __func__, ov7251->ctrls.error);
> + ret = ov7251->ctrls.error;
> + goto free_ctrl;
> + }
> +
> + v4l2_i2c_subdev_init(&ov7251->sd, client, &ov7251_subdev_ops);
> + ov7251->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> + ov7251->pad.flags = MEDIA_PAD_FL_SOURCE;
> + ov7251->sd.dev = &client->dev;
> + ov7251->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> +
> + ret = media_entity_pads_init(&ov7251->sd.entity, 1, &ov7251->pad);
> + if (ret < 0) {
> + dev_err(dev, "could not register media entity\n");
> + goto free_ctrl;
> + }
> +
> + ret = ov7251_s_power(&ov7251->sd, true);
> + if (ret < 0) {
> + dev_err(dev, "could not power up OV7251\n");
> + goto free_entity;
> + }
> +
> + ret = ov7251_read_reg(ov7251, OV7251_CHIP_ID_HIGH, &chip_id_high);
> + if (ret < 0 || chip_id_high != OV7251_CHIP_ID_HIGH_BYTE) {
> + dev_err(dev, "could not read ID high\n");
> + ret = -ENODEV;
> + goto power_down;
> + }
> + ret = ov7251_read_reg(ov7251, OV7251_CHIP_ID_LOW, &chip_id_low);
> + if (ret < 0 || chip_id_low != OV7251_CHIP_ID_LOW_BYTE) {
> + dev_err(dev, "could not read ID low\n");
> + ret = -ENODEV;
> + goto power_down;
> + }
> +
> + ret = ov7251_read_reg(ov7251, OV7251_SC_GP_IO_IN1, &chip_rev);
> + if (ret < 0) {
> + dev_err(dev, "could not read revision\n");
> + ret = -ENODEV;
> + goto power_down;
> + }
> + chip_rev >>= 4;
> +
> + dev_info(dev, "OV7251 revision %x (%s) detected at address 0x%02x\n",
> + chip_rev,
> + chip_rev == 0x4 ? "1A / 1B" :
> + chip_rev == 0x5 ? "1C / 1D" :
> + chip_rev == 0x6 ? "1E" :
> + chip_rev == 0x7 ? "1F" : "unknown",
> + client->addr);
> +
> + ret = ov7251_read_reg(ov7251, OV7251_PRE_ISP_00,
> + &ov7251->pre_isp_00);
> + if (ret < 0) {
> + dev_err(dev, "could not read test pattern value\n");
> + ret = -ENODEV;
> + goto power_down;
> + }
> +
> + ret = ov7251_read_reg(ov7251, OV7251_TIMING_FORMAT1,
> + &ov7251->timing_format1);
> + if (ret < 0) {
> + dev_err(dev, "could not read vflip value\n");
> + ret = -ENODEV;
> + goto power_down;
> + }
> +
> + ret = ov7251_read_reg(ov7251, OV7251_TIMING_FORMAT2,
> + &ov7251->timing_format2);
> + if (ret < 0) {
> + dev_err(dev, "could not read hflip value\n");
> + ret = -ENODEV;
> + goto power_down;
> + }
> +
> + ov7251_s_power(&ov7251->sd, false);
> +
> + ret = v4l2_async_register_subdev(&ov7251->sd);
> + if (ret < 0) {
> + dev_err(dev, "could not register v4l2 device\n");
> + goto free_entity;
> + }
> +
> + ov7251_entity_init_cfg(&ov7251->sd, NULL);
> +
> + return 0;
> +
> +power_down:
> + ov7251_s_power(&ov7251->sd, false);
> +free_entity:
> + media_entity_cleanup(&ov7251->sd.entity);
> +free_ctrl:
> + v4l2_ctrl_handler_free(&ov7251->ctrls);
> + mutex_destroy(&ov7251->power_lock);
> +
> + return ret;
> +}
> +
> +static int ov7251_remove(struct i2c_client *client)
> +{
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct ov7251 *ov7251 = to_ov7251(sd);
> +
> + v4l2_async_unregister_subdev(&ov7251->sd);
> + media_entity_cleanup(&ov7251->sd.entity);
> + v4l2_ctrl_handler_free(&ov7251->ctrls);
> + mutex_destroy(&ov7251->power_lock);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id ov7251_id[] = {
> + { "ov7251", 0 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(i2c, ov7251_id);
> +
> +static const struct of_device_id ov7251_of_match[] = {
> + { .compatible = "ovti,ov7251" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, ov7251_of_match);
> +
> +static struct i2c_driver ov7251_i2c_driver = {
> + .driver = {
> + .of_match_table = of_match_ptr(ov7251_of_match),
> + .name = "ov7251",
> + },
> + .probe = ov7251_probe,
> + .remove = ov7251_remove,
> + .id_table = ov7251_id,

As this driver depends on CONFIG_OF, I've been suggested to use probe_new and
get rid of i2c id_tables.

With the above nits clarified, and as you addressed my v1 comments:

Reviewed-by: Jacopo Mondi <jacopo@xxxxxxxxxx>

Thanks
j

> +};
> +
> +module_i2c_driver(ov7251_i2c_driver);
> +
> +MODULE_DESCRIPTION("Omnivision OV7251 Camera Driver");
> +MODULE_AUTHOR("Todor Tomov <todor.tomov@xxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");

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