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Date:   Thu, 27 Oct 2022 09:07:07 +0200
From:   Jacopo Mondi <jacopo@jmondi.org>
To:     Mikhail Rudenko <mike.rudenko@gmail.com>
Cc:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Shawn Tu <shawnx.tu@intel.com>,
        Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        Mike Pagano <mpagano@gentoo.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        Marek Vasut <marex@denx.de>, Jimmy Su <jimmy.su@intel.com>,
        linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 2/2] media: i2c: add support for OV4689
Message-ID: <20221027070707.34cryvomn7drtxpl@uno.localdomain>
References: <20221022162042.14113-1-mike.rudenko@gmail.com>
 <20221022162042.14113-3-mike.rudenko@gmail.com>
 <20221025130958.bnedjlkm6kmiluoe@uno.localdomain>
 <87y1t4gfvp.fsf@gmail.com>
MIME-Version: 1.0
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In-Reply-To: <87y1t4gfvp.fsf@gmail.com>
Precedence: bulk

Hi Mikhail

On Tue, Oct 25, 2022 at 04:51:02PM +0300, Mikhail Rudenko wrote:
>
> Hi Jacopo,
>
> On 2022-10-25 at 15:09 +02, Jacopo Mondi <jacopo@jmondi.org> wrote:
>
> > Hi Mikhail,
> >
> > On Sat, Oct 22, 2022 at 07:20:07PM +0300, Mikhail Rudenko wrote:
> >> Add a V4L2 sub-device driver for OmniVision OV4689 image sensor. This
> >> is a 4 Mpx image sensor using the I2C bus for control and the CSI-2
> >> bus for data.
> >>
> >> This driver supports following features:
> >> - manual exposure and analog gain control support
> >> - test pattern support
> >> - media controller support
> >> - runtime PM support
> >> - support following resolutions:
> >>   + 2688x1520 at 30 fps
> >>
> >> The driver provides all mandatory V4L2 controls for compatibility with
> >> libcamera. The sensor supports 1/2/4-lane CSI-2 modes, but the driver
> >> implements 4 lane mode only at this moment.
> >>
> >> Signed-off-by: Mikhail Rudenko <mike.rudenko@gmail.com>
> >> ---
> >>  MAINTAINERS                |    1 +
> >>  drivers/media/i2c/Kconfig  |   13 +
> >>  drivers/media/i2c/Makefile |    1 +
> >>  drivers/media/i2c/ov4689.c | 1026 ++++++++++++++++++++++++++++++++++++
> >>  4 files changed, 1041 insertions(+)
> >>  create mode 100644 drivers/media/i2c/ov4689.c
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> index 4d6d86a9f704..acf38afb3e73 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -15210,6 +15210,7 @@ L:	linux-media@vger.kernel.org
> >>  S:	Maintained
> >>  T:	git git://linuxtv.org/media_tree.git
> >>  F:	Documentation/devicetree/bindings/media/i2c/ovti,ov4689.yaml
> >> +F:	drivers/media/i2c/ov5647.c
> >>
> >>  OMNIVISION OV5640 SENSOR DRIVER
> >>  M:	Steve Longerbeam <slongerbeam@gmail.com>
> >> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> >> index 7806d4b81716..1e1985252ec8 100644
> >> --- a/drivers/media/i2c/Kconfig
> >> +++ b/drivers/media/i2c/Kconfig
> >> @@ -445,6 +445,19 @@ config VIDEO_OV2740
> >>  	  To compile this driver as a module, choose M here: the
> >>  	  module will be called ov2740.
> >>
> >> +config VIDEO_OV4689
> >> +	tristate "OmniVision OV4689 sensor support"
> >> +	depends on GPIOLIB && VIDEO_DEV && I2C
> >> +	select MEDIA_CONTROLLER
> >> +	select VIDEO_V4L2_SUBDEV_API
> >> +	select V4L2_FWNODE
> >> +	help
> >> +	  This is a Video4Linux2 sensor-level driver for the OmniVision
> >> +	  OV4689 camera.
> >> +
> >> +	  To compile this driver as a module, choose M here: the
> >> +	  module will be called ov4689.
> >> +
> >>  config VIDEO_OV5640
> >>  	tristate "OmniVision OV5640 sensor support"
> >>  	depends on OF
> >> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> >> index 0a2933103dd9..c1a2cb351c0f 100644
> >> --- a/drivers/media/i2c/Makefile
> >> +++ b/drivers/media/i2c/Makefile
> >> @@ -79,6 +79,7 @@ obj-$(CONFIG_VIDEO_OV2659) += ov2659.o
> >>  obj-$(CONFIG_VIDEO_OV2680) += ov2680.o
> >>  obj-$(CONFIG_VIDEO_OV2685) += ov2685.o
> >>  obj-$(CONFIG_VIDEO_OV2740) += ov2740.o
> >> +obj-$(CONFIG_VIDEO_OV4689) += ov4689.o
> >>  obj-$(CONFIG_VIDEO_OV5640) += ov5640.o
> >>  obj-$(CONFIG_VIDEO_OV5645) += ov5645.o
> >>  obj-$(CONFIG_VIDEO_OV5647) += ov5647.o
> >> diff --git a/drivers/media/i2c/ov4689.c b/drivers/media/i2c/ov4689.c
> >> new file mode 100644
> >> index 000000000000..419ff7371ba8
> >> --- /dev/null
> >> +++ b/drivers/media/i2c/ov4689.c
> >> @@ -0,0 +1,1026 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * ov4689 driver
> >> + *
> >> + * Copyright (C) 2017 Fuzhou Rockchip Electronics Co., Ltd.
> >> + * Copyright (C) 2022 Mikhail Rudenko
> >> + */
> >> +
> >> +#include <linux/clk.h>
> >> +#include <linux/delay.h>
> >> +#include <linux/gpio/consumer.h>
> >> +#include <linux/i2c.h>
> >> +#include <linux/module.h>
> >> +#include <linux/pm_runtime.h>
> >> +#include <linux/regulator/consumer.h>
> >> +#include <media/media-entity.h>
> >> +#include <media/v4l2-async.h>
> >> +#include <media/v4l2-ctrls.h>
> >> +#include <media/v4l2-subdev.h>
> >> +#include <media/v4l2-fwnode.h>
> >> +
> >> +#define CHIP_ID				0x004688
> >> +#define OV4689_REG_CHIP_ID		0x300a
> >> +
> >> +#define OV4689_XVCLK_FREQ		24000000
> >> +
> >> +#define OV4689_REG_CTRL_MODE		0x0100
> >> +#define OV4689_MODE_SW_STANDBY		0x0
> >> +#define OV4689_MODE_STREAMING		BIT(0)
> >> +
> >> +#define OV4689_REG_EXPOSURE		0x3500
> >> +#define OV4689_EXPOSURE_MIN		4
> >> +#define OV4689_EXPOSURE_STEP		1
> >> +#define OV4689_VTS_MAX			0x7fff
> >> +
> >> +#define OV4689_REG_GAIN_H		0x3508
> >> +#define OV4689_REG_GAIN_L		0x3509
> >> +#define OV4689_GAIN_H_MASK		0x07
> >> +#define OV4689_GAIN_H_SHIFT		8
> >> +#define OV4689_GAIN_L_MASK		0xff
> >> +#define OV4689_GAIN_STEP		1
> >> +#define OV4689_GAIN_DEFAULT		0x80
> >> +
> >> +#define OV4689_REG_TEST_PATTERN		0x5040
> >> +#define OV4689_TEST_PATTERN_ENABLE	0x80
> >> +#define OV4689_TEST_PATTERN_DISABLE	0x0
> >> +
> >> +#define OV4689_REG_VTS			0x380e
> >> +
> >> +#define REG_NULL			0xFFFF
> >> +
> >> +#define OV4689_REG_VALUE_08BIT		1
> >> +#define OV4689_REG_VALUE_16BIT		2
> >> +#define OV4689_REG_VALUE_24BIT		3
> >> +
> >> +#define OV4689_LANES			4
> >> +
> >> +static const char *const ov4689_supply_names[] = {
> >> +	"avdd", /* Analog power */
> >> +	"dovdd", /* Digital I/O power */
> >> +	"dvdd", /* Digital core power */
> >> +};
> >> +
> >> +struct regval {
> >> +	u16 addr;
> >> +	u8 val;
> >> +};
> >> +
> >> +enum ov4689_mode_id {
> >> +	OV4689_MODE_2688_1520 = 0,
> >> +	OV4689_NUM_MODES,
> >> +};
> >> +
> >> +struct ov4689_mode {
> >> +	enum ov4689_mode_id id;
> >> +	u32 width;
> >> +	u32 height;
> >> +	u32 max_fps;
> >> +	u32 hts_def;
> >> +	u32 vts_def;
> >> +	u32 exp_def;
> >> +	u32 pixel_rate;
> >> +	u32 sensor_width;
> >> +	u32 sensor_height;
> >> +	u32 crop_top;
> >> +	u32 crop_left;
> >> +	const struct regval *reg_list;
> >> +};
> >> +
> >> +struct ov4689 {
> >> +	struct i2c_client *client;
> >> +	struct clk *xvclk;
> >> +	struct gpio_desc *reset_gpio;
> >> +	struct gpio_desc *pwdn_gpio;
> >> +	struct regulator_bulk_data supplies[ARRAY_SIZE(ov4689_supply_names)];
> >> +
> >> +	struct v4l2_subdev subdev;
> >> +	struct media_pad pad;
> >> +
> >> +	u32 clock_rate;
> >> +
> >> +	struct mutex mutex; /* lock to protect streaming, ctrls and cur_mode */
> >> +	bool streaming;
> >> +	struct v4l2_ctrl_handler ctrl_handler;
> >> +	struct v4l2_ctrl *exposure;
> >> +
> >> +	const struct ov4689_mode *cur_mode;
> >> +};
> >> +
> >> +#define to_ov4689(sd) container_of(sd, struct ov4689, subdev)
> >> +
> >> +struct ov4689_gain_range {
> >> +	u32 logical_min;
> >> +	u32 logical_max;
> >> +	u32 offset;
> >> +	u32 divider;
> >> +	u32 physical_min;
> >> +	u32 physical_max;
> >> +};
> >> +
> >> +/*
> >> + * Xclk 24Mhz
> >> + * max_framerate 30fps
> >> + * mipi_datarate per lane 1008Mbps
> >> + */
> >> +static const struct regval ov4689_2688x1520_regs[] = {
> >> +	{0x0103, 0x01}, {0x3638, 0x00}, {0x0300, 0x00},
> >> +	{0x0302, 0x2a}, {0x0303, 0x00}, {0x0304, 0x03},
> >> +	{0x030b, 0x00}, {0x030d, 0x1e}, {0x030e, 0x04},
> >> +	{0x030f, 0x01}, {0x0312, 0x01}, {0x031e, 0x00},
> >> +	{0x3000, 0x20}, {0x3002, 0x00}, {0x3018, 0x72},
> >> +	{0x3020, 0x93}, {0x3021, 0x03}, {0x3022, 0x01},
> >> +	{0x3031, 0x0a}, {0x303f, 0x0c}, {0x3305, 0xf1},
> >> +	{0x3307, 0x04}, {0x3309, 0x29}, {0x3500, 0x00},
> >> +	{0x3501, 0x60}, {0x3502, 0x00}, {0x3503, 0x04},
> >> +	{0x3504, 0x00}, {0x3505, 0x00}, {0x3506, 0x00},
> >> +	{0x3507, 0x00}, {0x3508, 0x00}, {0x3509, 0x80},
> >> +	{0x350a, 0x00}, {0x350b, 0x00}, {0x350c, 0x00},
> >> +	{0x350d, 0x00}, {0x350e, 0x00}, {0x350f, 0x80},
> >> +	{0x3510, 0x00}, {0x3511, 0x00}, {0x3512, 0x00},
> >> +	{0x3513, 0x00}, {0x3514, 0x00}, {0x3515, 0x80},
> >> +	{0x3516, 0x00}, {0x3517, 0x00}, {0x3518, 0x00},
> >> +	{0x3519, 0x00}, {0x351a, 0x00}, {0x351b, 0x80},
> >> +	{0x351c, 0x00}, {0x351d, 0x00}, {0x351e, 0x00},
> >> +	{0x351f, 0x00}, {0x3520, 0x00}, {0x3521, 0x80},
> >> +	{0x3522, 0x08}, {0x3524, 0x08}, {0x3526, 0x08},
> >> +	{0x3528, 0x08}, {0x352a, 0x08}, {0x3602, 0x00},
> >> +	{0x3603, 0x40}, {0x3604, 0x02}, {0x3605, 0x00},
> >> +	{0x3606, 0x00}, {0x3607, 0x00}, {0x3609, 0x12},
> >> +	{0x360a, 0x40}, {0x360c, 0x08}, {0x360f, 0xe5},
> >> +	{0x3608, 0x8f}, {0x3611, 0x00}, {0x3613, 0xf7},
> >> +	{0x3616, 0x58}, {0x3619, 0x99}, {0x361b, 0x60},
> >> +	{0x361c, 0x7a}, {0x361e, 0x79}, {0x361f, 0x02},
> >> +	{0x3632, 0x00}, {0x3633, 0x10}, {0x3634, 0x10},
> >> +	{0x3635, 0x10}, {0x3636, 0x15}, {0x3646, 0x86},
> >> +	{0x364a, 0x0b}, {0x3700, 0x17}, {0x3701, 0x22},
> >> +	{0x3703, 0x10}, {0x370a, 0x37}, {0x3705, 0x00},
> >> +	{0x3706, 0x63}, {0x3709, 0x3c}, {0x370b, 0x01},
> >> +	{0x370c, 0x30}, {0x3710, 0x24}, {0x3711, 0x0c},
> >> +	{0x3716, 0x00}, {0x3720, 0x28}, {0x3729, 0x7b},
> >> +	{0x372a, 0x84}, {0x372b, 0xbd}, {0x372c, 0xbc},
> >> +	{0x372e, 0x52}, {0x373c, 0x0e}, {0x373e, 0x33},
> >> +	{0x3743, 0x10}, {0x3744, 0x88}, {0x3745, 0xc0},
> >> +	{0x374a, 0x43}, {0x374c, 0x00}, {0x374e, 0x23},
> >> +	{0x3751, 0x7b}, {0x3752, 0x84}, {0x3753, 0xbd},
> >> +	{0x3754, 0xbc}, {0x3756, 0x52}, {0x375c, 0x00},
> >> +	{0x3760, 0x00}, {0x3761, 0x00}, {0x3762, 0x00},
> >> +	{0x3763, 0x00}, {0x3764, 0x00}, {0x3767, 0x04},
> >> +	{0x3768, 0x04}, {0x3769, 0x08}, {0x376a, 0x08},
> >> +	{0x376b, 0x20}, {0x376c, 0x00}, {0x376d, 0x00},
> >> +	{0x376e, 0x00}, {0x3773, 0x00}, {0x3774, 0x51},
> >> +	{0x3776, 0xbd}, {0x3777, 0xbd}, {0x3781, 0x18},
> >> +	{0x3783, 0x25}, {0x3798, 0x1b}, {0x3800, 0x00},
> >> +	{0x3801, 0x08}, {0x3802, 0x00}, {0x3803, 0x04},
> >> +	{0x3804, 0x0a}, {0x3805, 0x97}, {0x3806, 0x05},
> >> +	{0x3807, 0xfb}, {0x3808, 0x0a}, {0x3809, 0x80},
> >> +	{0x380a, 0x05}, {0x380b, 0xf0}, {0x380c, 0x0a},
> >> +	{0x380d, 0x0e}, {0x380e, 0x06}, {0x380f, 0x12},
> >> +	{0x3810, 0x00}, {0x3811, 0x08}, {0x3812, 0x00},
> >> +	{0x3813, 0x04}, {0x3814, 0x01}, {0x3815, 0x01},
> >> +	{0x3819, 0x01}, {0x3820, 0x00}, {0x3821, 0x06},
> >> +	{0x3829, 0x00}, {0x382a, 0x01}, {0x382b, 0x01},
> >> +	{0x382d, 0x7f}, {0x3830, 0x04}, {0x3836, 0x01},
> >> +	{0x3837, 0x00}, {0x3841, 0x02}, {0x3846, 0x08},
> >> +	{0x3847, 0x07}, {0x3d85, 0x36}, {0x3d8c, 0x71},
> >> +	{0x3d8d, 0xcb}, {0x3f0a, 0x00}, {0x4000, 0xf1},
> >> +	{0x4001, 0x40}, {0x4002, 0x04}, {0x4003, 0x14},
> >> +	{0x400e, 0x00}, {0x4011, 0x00}, {0x401a, 0x00},
> >> +	{0x401b, 0x00}, {0x401c, 0x00}, {0x401d, 0x00},
> >> +	{0x401f, 0x00}, {0x4020, 0x00}, {0x4021, 0x10},
> >> +	{0x4022, 0x07}, {0x4023, 0xcf}, {0x4024, 0x09},
> >> +	{0x4025, 0x60}, {0x4026, 0x09}, {0x4027, 0x6f},
> >> +	{0x4028, 0x00}, {0x4029, 0x02}, {0x402a, 0x06},
> >> +	{0x402b, 0x04}, {0x402c, 0x02}, {0x402d, 0x02},
> >> +	{0x402e, 0x0e}, {0x402f, 0x04}, {0x4302, 0xff},
> >> +	{0x4303, 0xff}, {0x4304, 0x00}, {0x4305, 0x00},
> >> +	{0x4306, 0x00}, {0x4308, 0x02}, {0x4500, 0x6c},
> >> +	{0x4501, 0xc4}, {0x4502, 0x40}, {0x4503, 0x01},
> >> +	{0x4601, 0xa7}, {0x4800, 0x04}, {0x4813, 0x08},
> >> +	{0x481f, 0x40}, {0x4829, 0x78}, {0x4837, 0x10},
> >> +	{0x4b00, 0x2a}, {0x4b0d, 0x00}, {0x4d00, 0x04},
> >> +	{0x4d01, 0x42}, {0x4d02, 0xd1}, {0x4d03, 0x93},
> >> +	{0x4d04, 0xf5}, {0x4d05, 0xc1}, {0x5000, 0xf3},
> >> +	{0x5001, 0x11}, {0x5004, 0x00}, {0x500a, 0x00},
> >> +	{0x500b, 0x00}, {0x5032, 0x00}, {0x5040, 0x00},
> >> +	{0x5050, 0x0c}, {0x5500, 0x00}, {0x5501, 0x10},
> >> +	{0x5502, 0x01}, {0x5503, 0x0f}, {0x8000, 0x00},
> >> +	{0x8001, 0x00}, {0x8002, 0x00}, {0x8003, 0x00},
> >> +	{0x8004, 0x00}, {0x8005, 0x00}, {0x8006, 0x00},
> >> +	{0x8007, 0x00}, {0x8008, 0x00}, {0x3638, 0x00},
> >> +	{REG_NULL, 0x00},
> >> +};
> >> +
> >> +static const struct ov4689_mode supported_modes[] = {
> >> +	{
> >> +		.id = OV4689_MODE_2688_1520,
> >> +		.width = 2688,
> >> +		.height = 1520,
> >> +		.sensor_width = 2720,
> >> +		.sensor_height = 1536,
> >> +		.crop_top = 8,
> >> +		.crop_left = 16,
> >> +		.max_fps = 30,
> >> +		.exp_def = 1536,
> >> +		.hts_def = 4 * 2574,
> >> +		.vts_def = 1554,
> >> +		.pixel_rate = 480000000,
> >> +		.reg_list = ov4689_2688x1520_regs,
> >> +	},
> >> +};
> >> +
> >> +static const u64 link_freq_menu_items[] = { 504000000 };
> >> +
> >> +static const char *const ov4689_test_pattern_menu[] = {
> >> +	"Disabled",
> >> +	"Vertical Color Bar Type 1",
> >> +	"Vertical Color Bar Type 2",
> >> +	"Vertical Color Bar Type 3",
> >> +	"Vertical Color Bar Type 4"
> >> +};
> >> +
> >> +/*
> >> + * These coefficients are based on those used in Rockchip's camera
> >> + * engine, with minor tweaks for continuity.
> >> + */
> >> +static const struct ov4689_gain_range ov4689_gain_ranges[] = {
> >> +	{
> >> +		.logical_min = 0,
> >> +		.logical_max = 255,
> >> +		.offset = 0,
> >> +		.divider = 1,
> >> +		.physical_min = 0,
> >> +		.physical_max = 255,
> >> +	},
> >> +	{
> >> +		.logical_min = 256,
> >> +		.logical_max = 511,
> >> +		.offset = 252,
> >> +		.divider = 2,
> >> +		.physical_min = 376,
> >> +		.physical_max = 504,
> >> +	},
> >> +	{
> >> +		.logical_min = 512,
> >> +		.logical_max = 1023,
> >> +		.offset = 758,
> >> +		.divider = 4,
> >> +		.physical_min = 884,
> >> +		.physical_max = 1012,
> >> +	},
> >> +	{
> >> +		.logical_min = 1024,
> >> +		.logical_max = 2047,
> >> +		.offset = 1788,
> >> +		.divider = 8,
> >> +		.physical_min = 1912,
> >> +		.physical_max = 2047,
> >> +	},
> >> +};
> >> +
> >> +/* Write registers up to 4 at a time */
> >> +static int ov4689_write_reg(struct i2c_client *client, u16 reg, u32 len,
> >> +			    u32 val)
> >> +{
> >> +	u32 buf_i, val_i;
> >> +	__be32 val_be;
> >> +	u8 *val_p;
> >> +	u8 buf[6];
> >> +
> >> +	if (len > 4)
> >> +		return -EINVAL;
> >> +
> >> +	buf[0] = reg >> 8;
> >> +	buf[1] = reg & 0xff;
> >> +
> >> +	val_be = cpu_to_be32(val);
> >> +	val_p = (u8 *)&val_be;
> >> +	buf_i = 2;
> >> +	val_i = 4 - len;
> >> +
> >> +	while (val_i < 4)
> >> +		buf[buf_i++] = val_p[val_i++];
> >> +
> >> +	if (i2c_master_send(client, buf, len + 2) != len + 2)
> >> +		return -EIO;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_write_array(struct i2c_client *client,
> >> +			      const struct regval *regs)
> >> +{
> >> +	int ret = 0;
> >> +	u32 i;
> >> +
> >> +	for (i = 0; ret == 0 && regs[i].addr != REG_NULL; i++)
> >> +		ret = ov4689_write_reg(client, regs[i].addr,
> >> +				       OV4689_REG_VALUE_08BIT, regs[i].val);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/* Read registers up to 4 at a time */
> >> +static int ov4689_read_reg(struct i2c_client *client, u16 reg, unsigned int len,
> >> +			   u32 *val)
> >> +{
> >> +	__be16 reg_addr_be = cpu_to_be16(reg);
> >> +	struct i2c_msg msgs[2];
> >> +	__be32 data_be = 0;
> >> +	u8 *data_be_p;
> >> +	int ret;
> >> +
> >> +	if (len > 4 || !len)
> >> +		return -EINVAL;
> >> +
> >> +	data_be_p = (u8 *)&data_be;
> >> +	/* Write register address */
> >> +	msgs[0].addr = client->addr;
> >> +	msgs[0].flags = 0;
> >> +	msgs[0].len = 2;
> >> +	msgs[0].buf = (u8 *)&reg_addr_be;
> >> +
> >> +	/* Read data from register */
> >> +	msgs[1].addr = client->addr;
> >> +	msgs[1].flags = I2C_M_RD;
> >> +	msgs[1].len = len;
> >> +	msgs[1].buf = &data_be_p[4 - len];
> >> +
> >> +	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> >> +	if (ret != ARRAY_SIZE(msgs))
> >> +		return -EIO;
> >> +
> >> +	*val = be32_to_cpu(data_be);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static void ov4689_fill_fmt(const struct ov4689_mode *mode,
> >> +			    struct v4l2_mbus_framefmt *fmt)
> >> +{
> >> +	fmt->code = MEDIA_BUS_FMT_SBGGR10_1X10;
> >> +	fmt->width = mode->width;
> >> +	fmt->height = mode->height;
> >> +	fmt->field = V4L2_FIELD_NONE;
> >> +}
> >> +
> >> +static int ov4689_set_fmt(struct v4l2_subdev *sd,
> >> +			  struct v4l2_subdev_state *sd_state,
> >> +			  struct v4l2_subdev_format *fmt)
> >> +{
> >> +	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
> >> +	struct ov4689 *ov4689 = to_ov4689(sd);
> >> +
> >> +	/* only one mode supported for now */
> >> +	ov4689_fill_fmt(ov4689->cur_mode, mbus_fmt);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_get_fmt(struct v4l2_subdev *sd,
> >> +			  struct v4l2_subdev_state *sd_state,
> >> +			  struct v4l2_subdev_format *fmt)
> >> +{
> >> +	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
> >> +	struct ov4689 *ov4689 = to_ov4689(sd);
> >> +
> >> +	/* only one mode supported for now */
> >> +	ov4689_fill_fmt(ov4689->cur_mode, mbus_fmt);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				 struct v4l2_subdev_state *sd_state,
> >> +				 struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	if (code->index != 0)
> >> +		return -EINVAL;
> >> +	code->code = MEDIA_BUS_FMT_SBGGR10_1X10;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_enum_frame_sizes(struct v4l2_subdev *sd,
> >> +				   struct v4l2_subdev_state *sd_state,
> >> +				   struct v4l2_subdev_frame_size_enum *fse)
> >> +{
> >> +	if (fse->index >= ARRAY_SIZE(supported_modes))
> >> +		return -EINVAL;
> >> +
> >> +	if (fse->code != MEDIA_BUS_FMT_SBGGR10_1X10)
> >> +		return -EINVAL;
> >> +
> >> +	fse->min_width = supported_modes[fse->index].width;
> >> +	fse->max_width = supported_modes[fse->index].width;
> >> +	fse->max_height = supported_modes[fse->index].height;
> >> +	fse->min_height = supported_modes[fse->index].height;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_enable_test_pattern(struct ov4689 *ov4689, u32 pattern)
> >> +{
> >> +	u32 val;
> >> +
> >> +	if (pattern)
> >> +		val = (pattern - 1) | OV4689_TEST_PATTERN_ENABLE;
> >> +	else
> >> +		val = OV4689_TEST_PATTERN_DISABLE;
> >> +
> >> +	return ov4689_write_reg(ov4689->client, OV4689_REG_TEST_PATTERN,
> >> +				OV4689_REG_VALUE_08BIT, val);
> >> +}
> >> +
> >> +static int ov4689_get_selection(struct v4l2_subdev *sd,
> >> +				struct v4l2_subdev_state *state,
> >> +				struct v4l2_subdev_selection *sel)
> >> +{
> >> +	const struct ov4689_mode *mode = to_ov4689(sd)->cur_mode;
> >> +
> >> +	if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE)
> >> +		return -EINVAL;
> >> +
> >> +	switch (sel->target) {
> >> +	case V4L2_SEL_TGT_CROP_BOUNDS:
> >> +		sel->r.top = 0;
> >> +		sel->r.left = 0;
> >> +		sel->r.width = mode->sensor_width;
> >> +		sel->r.height = mode->sensor_height;
> >> +		return 0;
> >> +	case V4L2_SEL_TGT_CROP:
> >> +	case V4L2_SEL_TGT_CROP_DEFAULT:
> >> +		sel->r.top = mode->crop_top;
> >> +		sel->r.left = mode->crop_left;
> >> +		sel->r.width = mode->width;
> >> +		sel->r.height = mode->height;
> >> +		return 0;
> >> +	}
> >> +
> >> +	return -EINVAL;
> >> +}
> >> +
> >> +static int ov4689_s_stream(struct v4l2_subdev *sd, int on)
> >> +{
> >> +	struct ov4689 *ov4689 = to_ov4689(sd);
> >> +	struct i2c_client *client = ov4689->client;
> >> +	int ret = 0;
> >> +
> >> +	mutex_lock(&ov4689->mutex);
> >> +
> >> +	on = !!on;
> >> +	if (on == ov4689->streaming)
> >> +		goto unlock_and_return;
> >> +
> >> +	if (on) {
> >> +		ret = pm_runtime_resume_and_get(&client->dev);
> >> +		if (ret < 0)
> >> +			goto unlock_and_return;
> >> +
> >> +		ret = ov4689_write_array(ov4689->client,
> >> +					 ov4689->cur_mode->reg_list);
> >> +		if (ret) {
> >> +			pm_runtime_put(&client->dev);
> >> +			goto unlock_and_return;
> >> +		}
> >> +
> >> +		ret = __v4l2_ctrl_handler_setup(&ov4689->ctrl_handler);
> >> +		if (ret) {
> >> +			pm_runtime_put(&client->dev);
> >> +			goto unlock_and_return;
> >> +		}
> >> +
> >> +		ret = ov4689_write_reg(ov4689->client, OV4689_REG_CTRL_MODE,
> >> +				       OV4689_REG_VALUE_08BIT,
> >> +				       OV4689_MODE_STREAMING);
> >> +		if (ret) {
> >> +			pm_runtime_put(&client->dev);
> >> +			goto unlock_and_return;
> >> +		}
> >> +	} else {
> >> +		ov4689_write_reg(ov4689->client, OV4689_REG_CTRL_MODE,
> >> +				 OV4689_REG_VALUE_08BIT,
> >> +				 OV4689_MODE_SW_STANDBY);
> >> +		pm_runtime_put(&client->dev);
> >> +	}
> >> +
> >> +	ov4689->streaming = on;
> >> +
> >> +unlock_and_return:
> >> +	mutex_unlock(&ov4689->mutex);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/* Calculate the delay in us by clock rate and clock cycles */
> >> +static inline u32 ov4689_cal_delay(struct ov4689 *ov4689, u32 cycles)
> >> +{
> >> +	return DIV_ROUND_UP(cycles * 1000,
> >> +			    DIV_ROUND_UP(ov4689->clock_rate, 1000));
> >> +}
> >> +
> >> +static int __maybe_unused ov4689_power_on(struct device *dev)
> >> +{
> >> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >> +	struct ov4689 *ov4689 = to_ov4689(sd);
> >> +	u32 delay_us;
> >> +	int ret;
> >> +
> >> +	ret = clk_prepare_enable(ov4689->xvclk);
> >> +	if (ret < 0) {
> >> +		dev_err(dev, "Failed to enable xvclk\n");
> >> +		return ret;
> >> +	}
> >> +
> >> +	gpiod_set_value_cansleep(ov4689->reset_gpio, 1);
> >> +
> >> +	ret = regulator_bulk_enable(ARRAY_SIZE(ov4689_supply_names),
> >> +				    ov4689->supplies);
> >> +	if (ret < 0) {
> >> +		dev_err(dev, "Failed to enable regulators\n");
> >> +		goto disable_clk;
> >> +	}
> >> +
> >> +	gpiod_set_value_cansleep(ov4689->reset_gpio, 0);
> >> +	usleep_range(500, 1000);
> >> +	gpiod_set_value_cansleep(ov4689->pwdn_gpio, 0);
> >> +
> >> +	/* 8192 cycles prior to first SCCB transaction */
> >> +	delay_us = ov4689_cal_delay(ov4689, 8192);
> >> +	usleep_range(delay_us, delay_us * 2);
> >> +
> >> +	return 0;
> >> +
> >> +disable_clk:
> >> +	clk_disable_unprepare(ov4689->xvclk);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int __maybe_unused ov4689_power_off(struct device *dev)
> >> +{
> >> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >> +	struct ov4689 *ov4689 = to_ov4689(sd);
> >> +
> >> +	gpiod_set_value_cansleep(ov4689->pwdn_gpio, 1);
> >> +	clk_disable_unprepare(ov4689->xvclk);
> >> +	gpiod_set_value_cansleep(ov4689->reset_gpio, 1);
> >> +	regulator_bulk_disable(ARRAY_SIZE(ov4689_supply_names),
> >> +			       ov4689->supplies);
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> >> +{
> >> +	struct ov4689 *ov4689 = to_ov4689(sd);
> >> +	struct v4l2_mbus_framefmt *try_fmt;
> >> +
> >> +	mutex_lock(&ov4689->mutex);
> >> +
> >> +	try_fmt = v4l2_subdev_get_try_format(sd, fh->state, 0);
> >> +	/* Initialize try_fmt */
> >> +	ov4689_fill_fmt(&supported_modes[OV4689_MODE_2688_1520], try_fmt);
> >> +
> >> +	mutex_unlock(&ov4689->mutex);
> >> +
> >> +	return 0;
> >> +}
> >
> > FYI the centralized state support has been recently introduced in v4l2.
> > It allows you (among other things) to replace open with init_cfg and
> > centralize the handling of formats initialization. This driver only
> > supports one format, so no big deal.
>
> Could you point me at some documentation/example code on this? I think
> at some point in future (after the driver is accepted) I'll be
> implementing more modes (at least 2x2 and 4x4 binning) and the
> centralized state will come in useful.
>

https://kernel.org/doc/html/latest/driver-api/media/v4l2-subdev.html#centrally-managed-subdev-active-state

Unfortunately I don't see users yet in mainline, Tomi has a branch
git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux.git #streams/work-v15
with subdev drivers ported to the new state API.

I do have some experiments here as well, mostly interesting to show
how to move format configuration to the subdev state:
https://git.sr.ht/~jmondi_/linux/log/multistream/media-master/tomba-v10/niklas/adv748x

Centralized state support won't make things much simpler when it comes
to supporting new modes, but it will make it possible to support
routing (required if your sensor supports embedded data) and
simplifies format handling. It would be nice for new drivers to try to
use it :)

> >> +
> >> +static const struct dev_pm_ops ov4689_pm_ops = {
> >> +	SET_RUNTIME_PM_OPS(ov4689_power_off, ov4689_power_on, NULL)
> >> +};
> >> +
> >> +static const struct v4l2_subdev_internal_ops ov4689_internal_ops = {
> >> +	.open = ov4689_open,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_video_ops ov4689_video_ops = {
> >> +	.s_stream = ov4689_s_stream,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_pad_ops ov4689_pad_ops = {
> >> +	.enum_mbus_code = ov4689_enum_mbus_code,
> >> +	.enum_frame_size = ov4689_enum_frame_sizes,
> >> +	.get_fmt = ov4689_get_fmt,
> >> +	.set_fmt = ov4689_set_fmt,
> >> +	.get_selection = ov4689_get_selection,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_ops ov4689_subdev_ops = {
> >> +	.video = &ov4689_video_ops,
> >> +	.pad = &ov4689_pad_ops,
> >> +};
> >> +
> >> +/*
> >> + * Map userspace (logical) gain to sensor (physical) gain using
> >> + * ov4689_gain_ranges table.
> >> + */
> >> +static int ov4689_map_gain(struct ov4689 *ov4689, int logical_gain, int *result)
> >> +{
> >> +	const struct device *dev = &ov4689->client->dev;
> >> +	const struct ov4689_gain_range *range;
> >> +	unsigned int n;
> >> +
> >> +	for (n = 0; n < ARRAY_SIZE(ov4689_gain_ranges); n++) {
> >> +		if (logical_gain >= ov4689_gain_ranges[n].logical_min &&
> >> +		    logical_gain <= ov4689_gain_ranges[n].logical_max) {
> >> +			break;
> >> +		}
> >
> > No need for {} here
> >
>
> Will fix in v5. I wonder, why doesn't checkpatch.pl catch ones like this?..
>
> >> +	}
> >> +
> >> +	if (n == ARRAY_SIZE(ov4689_gain_ranges)) {
> >> +		dev_warn_ratelimited(dev, "no mapping found for gain %d\n",
> >> +				     logical_gain);
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	range = &ov4689_gain_ranges[n];
> >> +
> >> +	*result = clamp(range->offset + (logical_gain) / range->divider,
> >> +			range->physical_min, range->physical_max);
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_set_ctrl(struct v4l2_ctrl *ctrl)
> >> +{
> >> +	struct ov4689 *ov4689 =
> >> +		container_of(ctrl->handler, struct ov4689, ctrl_handler);
> >> +	struct i2c_client *client = ov4689->client;
> >> +	int sensor_gain;
> >> +	s64 max_expo;
> >> +	int ret;
> >> +
> >> +	/* Propagate change of current control to all related controls */
> >> +	switch (ctrl->id) {
> >> +	case V4L2_CID_VBLANK:
> >> +		/* Update max exposure while meeting expected vblanking */
> >> +		max_expo = ov4689->cur_mode->height + ctrl->val - 4;
> >> +		__v4l2_ctrl_modify_range(ov4689->exposure,
> >> +					 ov4689->exposure->minimum, max_expo,
> >> +					 ov4689->exposure->step,
> >> +					 ov4689->exposure->default_value);
> >> +		break;
> >> +	}
> >> +
> >> +	if (!pm_runtime_get_if_in_use(&client->dev))
> >> +		return 0;
> >> +
> >> +	switch (ctrl->id) {
> >> +	case V4L2_CID_EXPOSURE:
> >> +		/* 4 least significant bits of expsoure are fractional part */
> >> +		ret = ov4689_write_reg(ov4689->client, OV4689_REG_EXPOSURE,
> >> +				       OV4689_REG_VALUE_24BIT, ctrl->val << 4);
> >> +		break;
> >> +	case V4L2_CID_ANALOGUE_GAIN:
> >> +		ret = ov4689_map_gain(ov4689, ctrl->val, &sensor_gain);
> >> +
> >> +		ret = ret ?:
> >> +			ov4689_write_reg(ov4689->client, OV4689_REG_GAIN_H,
> >> +					 OV4689_REG_VALUE_08BIT,
> >> +					 (sensor_gain >> OV4689_GAIN_H_SHIFT) &
> >> +					 OV4689_GAIN_H_MASK);
> >> +		ret = ret ?:
> >> +			ov4689_write_reg(ov4689->client, OV4689_REG_GAIN_L,
> >> +					 OV4689_REG_VALUE_08BIT,
> >> +					 sensor_gain & OV4689_GAIN_L_MASK);
> >> +		break;
> >> +	case V4L2_CID_VBLANK:
> >> +		ret = ov4689_write_reg(ov4689->client, OV4689_REG_VTS,
> >> +				       OV4689_REG_VALUE_16BIT,
> >> +				       ctrl->val + ov4689->cur_mode->height);
> >> +		break;
> >> +	case V4L2_CID_TEST_PATTERN:
> >> +		ret = ov4689_enable_test_pattern(ov4689, ctrl->val);
> >> +		break;
> >> +	default:
> >> +		dev_warn(&client->dev, "%s Unhandled id:0x%x, val:0x%x\n",
> >> +			 __func__, ctrl->id, ctrl->val);
> >> +		ret = -EINVAL;
> >> +		break;
> >> +	}
> >> +
> >> +	pm_runtime_put(&client->dev);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static const struct v4l2_ctrl_ops ov4689_ctrl_ops = {
> >> +	.s_ctrl = ov4689_set_ctrl,
> >> +};
> >> +
> >> +static int ov4689_initialize_controls(struct ov4689 *ov4689)
> >> +{
> >> +	struct i2c_client *client = v4l2_get_subdevdata(&ov4689->subdev);
> >> +	struct v4l2_fwnode_device_properties props;
> >> +	struct v4l2_ctrl_handler *handler;
> >> +	const struct ov4689_mode *mode;
> >> +	s64 exposure_max, vblank_def;
> >> +	struct v4l2_ctrl *ctrl;
> >> +	s64 h_blank_def;
> >> +	int ret;
> >> +
> >> +	handler = &ov4689->ctrl_handler;
> >> +	mode = ov4689->cur_mode;
> >> +	ret = v4l2_ctrl_handler_init(handler, 10);
> >> +	if (ret)
> >> +		return ret;
> >> +	handler->lock = &ov4689->mutex;
> >> +
> >> +	ctrl = v4l2_ctrl_new_int_menu(handler, NULL, V4L2_CID_LINK_FREQ, 0, 0,
> >> +				      link_freq_menu_items);
> >> +	if (ctrl)
> >> +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >> +
> >> +	v4l2_ctrl_new_std(handler, NULL, V4L2_CID_PIXEL_RATE, 0,
> >> +			  mode->pixel_rate, 1, mode->pixel_rate);
> >> +
> >> +	h_blank_def = mode->hts_def - mode->width;
> >> +	ctrl = v4l2_ctrl_new_std(handler, NULL, V4L2_CID_HBLANK, h_blank_def,
> >> +				 h_blank_def, 1, h_blank_def);
> >> +	if (ctrl)
> >> +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >> +
> >> +	vblank_def = mode->vts_def - mode->height;
> >> +	v4l2_ctrl_new_std(handler, &ov4689_ctrl_ops, V4L2_CID_VBLANK,
> >> +			  vblank_def, OV4689_VTS_MAX - mode->height, 1,
> >> +			  vblank_def);
> >> +
> >> +	exposure_max = mode->vts_def - 4;
> >> +	ov4689->exposure =
> >> +		v4l2_ctrl_new_std(handler, &ov4689_ctrl_ops, V4L2_CID_EXPOSURE,
> >> +				  OV4689_EXPOSURE_MIN, exposure_max,
> >> +				  OV4689_EXPOSURE_STEP, mode->exp_def);
> >> +
> >> +	v4l2_ctrl_new_std(handler, &ov4689_ctrl_ops, V4L2_CID_ANALOGUE_GAIN,
> >> +			  ov4689_gain_ranges[0].logical_min,
> >> +			  ov4689_gain_ranges[ARRAY_SIZE(ov4689_gain_ranges) - 1]
> >> +				  .logical_max,
> >> +			  OV4689_GAIN_STEP, OV4689_GAIN_DEFAULT);
> >> +
> >> +	v4l2_ctrl_new_std_menu_items(handler, &ov4689_ctrl_ops,
> >> +				     V4L2_CID_TEST_PATTERN,
> >> +				     ARRAY_SIZE(ov4689_test_pattern_menu) - 1,
> >> +				     0, 0, ov4689_test_pattern_menu);
> >> +
> >> +	if (handler->error) {
> >> +		ret = handler->error;
> >> +		dev_err(&ov4689->client->dev, "Failed to init controls(%d)\n",
> >> +			ret);
> >> +		goto err_free_handler;
> >> +	}
> >> +
> >> +	ret = v4l2_fwnode_device_parse(&client->dev, &props);
> >> +	if (ret)
> >> +		goto err_free_handler;
> >> +
> >> +	ret = v4l2_ctrl_new_fwnode_properties(handler, &ov4689_ctrl_ops,
> >> +					      &props);
> >> +	if (ret)
> >> +		goto err_free_handler;
> >> +
> >> +	ov4689->subdev.ctrl_handler = handler;
> >> +
> >> +	return 0;
> >> +
> >> +err_free_handler:
> >> +	v4l2_ctrl_handler_free(handler);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int ov4689_check_sensor_id(struct ov4689 *ov4689,
> >> +				  struct i2c_client *client)
> >> +{
> >> +	struct device *dev = &ov4689->client->dev;
> >> +	u32 id = 0;
> >> +	int ret;
> >> +
> >> +	ret = ov4689_read_reg(client, OV4689_REG_CHIP_ID,
> >> +			      OV4689_REG_VALUE_16BIT, &id);
> >> +	if (ret) {
> >> +		dev_err(dev, "Cannot read sensor ID\n");
> >> +		return ret;
> >> +	}
> >> +
> >> +	if (id != CHIP_ID) {
> >> +		dev_err(dev, "Unexpected sensor ID %06x, expected %06x\n",
> >> +			id, CHIP_ID);
> >> +		return -ENODEV;
> >> +	}
> >> +
> >> +	dev_info(dev, "Detected OV%06x sensor\n", CHIP_ID);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_configure_regulators(struct ov4689 *ov4689)
> >> +{
> >> +	unsigned int supplies_count = ARRAY_SIZE(ov4689_supply_names);
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < supplies_count; i++)
> >> +		ov4689->supplies[i].supply = ov4689_supply_names[i];
> >> +
> >> +	return devm_regulator_bulk_get(&ov4689->client->dev, supplies_count,
> >> +				       ov4689->supplies);
> >> +}
> >> +
> >> +static u64 ov4689_check_link_frequency(struct v4l2_fwnode_endpoint *ep)
> >> +{
> >> +	unsigned int freqs_count = ARRAY_SIZE(link_freq_menu_items);
> >> +	const u64 *freqs = link_freq_menu_items;
> >> +	unsigned int i, j;
> >> +
> >> +	for (i = 0; i < freqs_count; i++) {
> >> +		for (j = 0; j < ep->nr_of_link_frequencies; j++)
> >> +			if (freqs[i] == ep->link_frequencies[j])
> >> +				return freqs[i];
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int ov4689_check_hwcfg(struct device *dev)
> >> +{
> >> +	struct fwnode_handle *fwnode = dev_fwnode(dev);
> >> +	struct v4l2_fwnode_endpoint bus_cfg = {
> >> +		.bus_type = V4L2_MBUS_CSI2_DPHY,
> >> +	};
> >> +	struct fwnode_handle *endpoint;
> >> +	int ret;
> >> +
> >> +	endpoint = fwnode_graph_get_next_endpoint(fwnode, NULL);
> >> +	if (!endpoint)
> >> +		return -EINVAL;
> >> +
> >> +	ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &bus_cfg);
> >> +	fwnode_handle_put(endpoint);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	if (bus_cfg.bus.mipi_csi2.num_data_lanes != OV4689_LANES) {
> >> +		dev_err(dev, "Only a 4-lane CSI2 config is supported");
> >> +		ret = -EINVAL;
> >> +		goto out_free_bus_cfg;
> >> +	}
> >> +
> >> +	if (!bus_cfg.nr_of_link_frequencies) {
> >> +		dev_err(dev, "No link frequencies defined\n");
> >> +		ret = -EINVAL;
> >> +		goto out_free_bus_cfg;
> >> +	}
> >
> > As the driver has a single supported freq I wonder if it is required
> > to have it mandatory. I got contradictory feedbacks in the past, so
> > whatever you have here I guess it's fine (same reasoning goes for dts,
> > if there's only one accepted item, does it need to be made mandatory
> > ?)
> >
> > Nits apart, the driver looks sane
> >
> > Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>
> Thanks for the review, Jacopo!
>
> > Thanks
> >   j
> >
> >> +
> >> +	if (!ov4689_check_link_frequency(&bus_cfg)) {
> >> +		dev_err(dev, "No supported link frequency found\n");
> >> +		ret = -EINVAL;
> >> +	}
> >> +
> >> +out_free_bus_cfg:
> >> +	v4l2_fwnode_endpoint_free(&bus_cfg);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int ov4689_probe(struct i2c_client *client)
> >> +{
> >> +	struct device *dev = &client->dev;
> >> +	struct v4l2_subdev *sd;
> >> +	struct ov4689 *ov4689;
> >> +	int ret;
> >> +
> >> +	ret = ov4689_check_hwcfg(dev);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	ov4689 = devm_kzalloc(dev, sizeof(*ov4689), GFP_KERNEL);
> >> +	if (!ov4689)
> >> +		return -ENOMEM;
> >> +
> >> +	ov4689->client = client;
> >> +	ov4689->cur_mode = &supported_modes[OV4689_MODE_2688_1520];
> >> +
> >> +	ov4689->xvclk = devm_clk_get_optional(dev, NULL);
> >> +	if (IS_ERR(ov4689->xvclk))
> >> +		return dev_err_probe(dev, PTR_ERR(ov4689->xvclk),
> >> +				     "Failed to get external clock\n");
> >> +
> >> +	if (!ov4689->xvclk) {
> >> +		dev_dbg(dev,
> >> +			"No clock provided, using clock-frequency property\n");
> >> +		device_property_read_u32(dev, "clock-frequency",
> >> +					 &ov4689->clock_rate);
> >> +	} else {
> >> +		ov4689->clock_rate = clk_get_rate(ov4689->xvclk);
> >> +	}
> >> +
> >> +	if (ov4689->clock_rate != OV4689_XVCLK_FREQ) {
> >> +		dev_err(dev,
> >> +			"External clock rate mismatch: got %d Hz, expected %d Hz\n",
> >> +			ov4689->clock_rate, OV4689_XVCLK_FREQ);
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	ov4689->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> >> +						     GPIOD_OUT_LOW);
> >> +	if (IS_ERR(ov4689->reset_gpio)) {
> >> +		dev_err(dev, "Failed to get reset-gpios\n");
> >> +		return PTR_ERR(ov4689->reset_gpio);
> >> +	}
> >> +
> >> +	ov4689->pwdn_gpio = devm_gpiod_get_optional(dev, "pwdn", GPIOD_OUT_LOW);
> >> +	if (IS_ERR(ov4689->pwdn_gpio)) {
> >> +		dev_err(dev, "Failed to get pwdn-gpios\n");
> >> +		return PTR_ERR(ov4689->pwdn_gpio);
> >> +	}
> >> +
> >> +	ret = ov4689_configure_regulators(ov4689);
> >> +	if (ret)
> >> +		return dev_err_probe(dev, ret,
> >> +				     "Failed to get power regulators\n");
> >> +
> >> +	mutex_init(&ov4689->mutex);
> >> +
> >> +	sd = &ov4689->subdev;
> >> +	v4l2_i2c_subdev_init(sd, client, &ov4689_subdev_ops);
> >> +	ret = ov4689_initialize_controls(ov4689);
> >> +	if (ret)
> >> +		goto err_destroy_mutex;
> >> +
> >> +	ret = ov4689_power_on(dev);
> >> +	if (ret)
> >> +		goto err_free_handler;
> >> +
> >> +	ret = ov4689_check_sensor_id(ov4689, client);
> >> +	if (ret)
> >> +		goto err_power_off;
> >> +
> >> +	sd->internal_ops = &ov4689_internal_ops;
> >> +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> >> +
> >> +	ov4689->pad.flags = MEDIA_PAD_FL_SOURCE;
> >> +	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
> >> +	ret = media_entity_pads_init(&sd->entity, 1, &ov4689->pad);
> >> +	if (ret < 0)
> >> +		goto err_power_off;
> >> +
> >> +	ret = v4l2_async_register_subdev_sensor(sd);
> >> +	if (ret) {
> >> +		dev_err(dev, "v4l2 async register subdev failed\n");
> >> +		goto err_clean_entity;
> >> +	}
> >> +
> >> +	pm_runtime_set_active(dev);
> >> +	pm_runtime_enable(dev);
> >> +	pm_runtime_idle(dev);
> >> +
> >> +	return 0;
> >> +
> >> +err_clean_entity:
> >> +	media_entity_cleanup(&sd->entity);
> >> +err_power_off:
> >> +	ov4689_power_off(dev);
> >> +err_free_handler:
> >> +	v4l2_ctrl_handler_free(&ov4689->ctrl_handler);
> >> +err_destroy_mutex:
> >> +	mutex_destroy(&ov4689->mutex);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static void ov4689_remove(struct i2c_client *client)
> >> +{
> >> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> >> +	struct ov4689 *ov4689 = to_ov4689(sd);
> >> +
> >> +	v4l2_async_unregister_subdev(sd);
> >> +	media_entity_cleanup(&sd->entity);
> >> +
> >> +	v4l2_ctrl_handler_free(&ov4689->ctrl_handler);
> >> +	mutex_destroy(&ov4689->mutex);
> >> +
> >> +	pm_runtime_disable(&client->dev);
> >> +	if (!pm_runtime_status_suspended(&client->dev))
> >> +		ov4689_power_off(&client->dev);
> >> +	pm_runtime_set_suspended(&client->dev);
> >> +}
> >> +
> >> +static const struct of_device_id ov4689_of_match[] = {
> >> +	{ .compatible = "ovti,ov4689" },
> >> +	{},
> >> +};
> >> +MODULE_DEVICE_TABLE(of, ov4689_of_match);
> >> +
> >> +static struct i2c_driver ov4689_i2c_driver = {
> >> +	.driver = {
> >> +		.name = "ov4689",
> >> +		.pm = &ov4689_pm_ops,
> >> +		.of_match_table = ov4689_of_match,
> >> +	},
> >> +	.probe_new = ov4689_probe,
> >> +	.remove	= ov4689_remove,
> >> +};
> >> +
> >> +module_i2c_driver(ov4689_i2c_driver);
> >> +
> >> +MODULE_DESCRIPTION("OmniVision ov4689 sensor driver");
> >> +MODULE_LICENSE("GPL");
> >> --
> >> 2.38.1
> >>
>
>
> --
> Best regards,
> Mikhail Rudenko