Re: [V1, 2/2] media: i2c: Add more sensor mode for ov8856 camera sensor

Sakari Ailus
2019-08-08T13:53:10Z

Hi Dongchun,

Thanks for the patch.

On Thu, Aug 08, 2019 at 05:22:15PM +0800, dongchun.zhu@mediatek.com wrote:
> From: Dongchun Zhu <dongchun.zhu@mediatek.com>
>
> This patch mainly adds two more sensor modes for OV8856 image sensor.
> The OV8856 driver currently supports output format: 10-bit Raw,
> the resolution of 1632*1224 and 3264*2448, and the bayer order of BGGR.
> The hardware version also differs in some OTP regiser,
> as well as PLL register setting.
>
> Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> ---
> drivers/media/i2c/ov8856.c | 624 ++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 621 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/i2c/ov8856.c b/drivers/media/i2c/ov8856.c
> index cd347d6..e0610b6 100644
> --- a/drivers/media/i2c/ov8856.c
> +++ b/drivers/media/i2c/ov8856.c
> @@ -1,12 +1,15 @@
> // SPDX-License-Identifier: GPL-2.0
> // Copyright (c) 2019 Intel Corporation.
>
> +#include <linux/clk.h>
> #include <asm/unaligned.h>
> #include <linux/acpi.h>
> #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/i2c.h>
> #include <linux/module.h>
> #include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> #include <media/v4l2-ctrls.h>
> #include <media/v4l2-device.h>
> #include <media/v4l2-fwnode.h>
> @@ -19,6 +22,7 @@
> #define OV8856_LINK_FREQ_180MHZ 180000000ULL
> #define OV8856_SCLK 144000000ULL
> #define OV8856_MCLK 19200000
> +#define OV8856_XVCLK_FREQ 24000000

The driver currenctly uses, perhaps misleadingly, OV8856_MCLK for this
purpose. You could rename the existing MCLK as XVCLK.

This also means the driver needs to differentiate configurations for 24 and
19,2 MHz which it currently does not do. I think it may make sense to make
this a separate patch from the rest.

> #define OV8856_DATA_LANES 4
> #define OV8856_RGB_DEPTH 10
>
> @@ -29,6 +33,18 @@
> #define OV8856_MODE_STANDBY 0x00
> #define OV8856_MODE_STREAMING 0x01
>
> +/* define 1B module */
> +#define OV8856_1B_MODULE 0x02
> +
> +/* otp sram register */
> +#define OV8856_OTP_REG 0x700f
> +#define OV8856_OTP_REG_ONE 0x3d84
> +#define OV8856_OTP_REG_TWO 0x3d81
> +
> +/* clock register */
> +#define OV8856_CLK_REG 0x3614
> +#define OV8856_CLK_REG_1B_VAL 0x20
> +
> /* vertical-timings from sensor */
> #define OV8856_REG_VTS 0x380e
> #define OV8856_VTS_MAX 0x7fff
> @@ -64,6 +80,14 @@
>
> #define to_ov8856(_sd) container_of(_sd, struct ov8856, sd)
>
> +static const char * const ov8856_supply_names[] = {
> + "dovdd", /* Digital I/O power */
> + "avdd", /* Analog power */
> + "dvdd", /* Digital core power */
> +};
> +
> +#define OV8856_NUM_SUPPLIES ARRAY_SIZE(ov8856_supply_names)
> +
> enum {
> OV8856_LINK_FREQ_720MBPS,
> OV8856_LINK_FREQ_360MBPS,
> @@ -316,6 +340,208 @@ static const struct ov8856_reg mode_3280x2464_regs[] = {
> {0x5e00, 0x00}
> };
>
> +static const struct ov8856_reg mode_3264x2448_regs[] = {
> + {0x0103, 0x01},
> + {0x0302, 0x3c},
> + {0x0303, 0x01},
> + {0x031e, 0x0c},
> + {0x3000, 0x00},
> + {0x300e, 0x00},
> + {0x3010, 0x00},
> + {0x3015, 0x84},
> + {0x3018, 0x72},
> + {0x3021, 0x23},
> + {0x3033, 0x24},
> + {0x3500, 0x00},
> + {0x3501, 0x9a},
> + {0x3502, 0x20},
> + {0x3503, 0x08},
> + {0x3505, 0x83},
> + {0x3508, 0x01},
> + {0x3509, 0x80},
> + {0x350c, 0x00},
> + {0x350d, 0x80},
> + {0x350e, 0x04},
> + {0x350f, 0x00},
> + {0x3510, 0x00},
> + {0x3511, 0x02},
> + {0x3512, 0x00},
> + {0x3600, 0x72},
> + {0x3601, 0x40},
> + {0x3602, 0x30},
> + {0x3610, 0xc5},
> + {0x3611, 0x58},
> + {0x3612, 0x5c},
> + {0x3613, 0xca},
> + {0x3614, 0x60},
> + {0x3628, 0xff},
> + {0x3629, 0xff},
> + {0x362a, 0xff},
> + {0x3633, 0x10},
> + {0x3634, 0x10},
> + {0x3635, 0x10},
> + {0x3636, 0x10},
> + {0x3663, 0x08},
> + {0x3669, 0x34},
> + {0x366d, 0x00},
> + {0x366e, 0x10},
> + {0x3706, 0x86},
> + {0x370b, 0x7e},
> + {0x3714, 0x23},
> + {0x3730, 0x12},
> + {0x3733, 0x10},
> + {0x3764, 0x00},
> + {0x3765, 0x00},
> + {0x3769, 0x62},
> + {0x376a, 0x2a},
> + {0x376b, 0x30},
> + {0x3780, 0x00},
> + {0x3781, 0x24},
> + {0x3782, 0x00},
> + {0x3783, 0x23},
> + {0x3798, 0x2f},
> + {0x37a1, 0x60},
> + {0x37a8, 0x6a},
> + {0x37ab, 0x3f},
> + {0x37c2, 0x04},
> + {0x37c3, 0xf1},
> + {0x37c9, 0x80},
> + {0x37cb, 0x16},
> + {0x37cc, 0x16},
> + {0x37cd, 0x16},
> + {0x37ce, 0x16},
> + {0x3800, 0x00},
> + {0x3801, 0x00},
> + {0x3802, 0x00},
> + {0x3803, 0x0c},
> + {0x3804, 0x0c},
> + {0x3805, 0xdf},
> + {0x3806, 0x09},
> + {0x3807, 0xa3},
> + {0x3808, 0x0c},
> + {0x3809, 0xc0},
> + {0x380a, 0x09},
> + {0x380b, 0x90},
> + {0x380c, 0x07},
> + {0x380d, 0x8c},
> + {0x380e, 0x09},
> + {0x380f, 0xb2},
> + {0x3810, 0x00},
> + {0x3811, 0x04},
> + {0x3812, 0x00},
> + {0x3813, 0x02},
> + {0x3814, 0x01},
> + {0x3815, 0x01},
> + {0x3816, 0x00},
> + {0x3817, 0x00},
> + {0x3818, 0x00},
> + {0x3819, 0x00},
> + {0x3820, 0x80},
> + {0x3821, 0x46},
> + {0x382a, 0x01},
> + {0x382b, 0x01},
> + {0x3830, 0x06},
> + {0x3836, 0x02},
> + {0x3862, 0x04},
> + {0x3863, 0x08},
> + {0x3cc0, 0x33},
> + {0x3d85, 0x17},
> + {0x3d8c, 0x73},
> + {0x3d8d, 0xde},
> + {0x4001, 0xe0},
> + {0x4003, 0x40},
> + {0x4008, 0x00},
> + {0x4009, 0x0b},
> + {0x400a, 0x00},
> + {0x400b, 0x84},
> + {0x400f, 0x80},
> + {0x4010, 0xf0},
> + {0x4011, 0xff},
> + {0x4012, 0x02},
> + {0x4013, 0x01},
> + {0x4014, 0x01},
> + {0x4015, 0x01},
> + {0x4042, 0x00},
> + {0x4043, 0x80},
> + {0x4044, 0x00},
> + {0x4045, 0x80},
> + {0x4046, 0x00},
> + {0x4047, 0x80},
> + {0x4048, 0x00},
> + {0x4049, 0x80},
> + {0x4041, 0x03},
> + {0x404c, 0x20},
> + {0x404d, 0x00},
> + {0x404e, 0x20},
> + {0x4203, 0x80},
> + {0x4307, 0x30},
> + {0x4317, 0x00},
> + {0x4502, 0x50},
> + {0x4503, 0x08},
> + {0x4601, 0x80},
> + {0x4800, 0x44},
> + {0x4816, 0x53},
> + {0x481b, 0x50},
> + {0x481f, 0x27},
> + {0x4823, 0x3c},
> + {0x482b, 0x00},
> + {0x4831, 0x66},
> + {0x4837, 0x16},
> + {0x483c, 0x0f},
> + {0x484b, 0x05},
> + {0x5000, 0x77},
> + {0x5001, 0x0a},
> + {0x5003, 0xc8},
> + {0x5004, 0x04},
> + {0x5006, 0x00},
> + {0x5007, 0x00},
> + {0x502e, 0x03},
> + {0x5030, 0x41},
> + {0x5780, 0x14},
> + {0x5781, 0x0f},
> + {0x5782, 0x44},
> + {0x5783, 0x02},
> + {0x5784, 0x01},
> + {0x5785, 0x01},
> + {0x5786, 0x00},
> + {0x5787, 0x04},
> + {0x5788, 0x02},
> + {0x5789, 0x0f},
> + {0x578a, 0xfd},
> + {0x578b, 0xf5},
> + {0x578c, 0xf5},
> + {0x578d, 0x03},
> + {0x578e, 0x08},
> + {0x578f, 0x0c},
> + {0x5790, 0x08},
> + {0x5791, 0x04},
> + {0x5792, 0x00},
> + {0x5793, 0x52},
> + {0x5794, 0xa3},
> + {0x5795, 0x02},
> + {0x5796, 0x20},
> + {0x5797, 0x20},
> + {0x5798, 0xd5},
> + {0x5799, 0xd5},
> + {0x579a, 0x00},
> + {0x579b, 0x50},
> + {0x579c, 0x00},
> + {0x579d, 0x2c},
> + {0x579e, 0x0c},
> + {0x579f, 0x40},
> + {0x57a0, 0x09},
> + {0x57a1, 0x40},
> + {0x59f8, 0x3d},
> + {0x5a08, 0x02},
> + {0x5b00, 0x02},
> + {0x5b01, 0x10},
> + {0x5b02, 0x03},
> + {0x5b03, 0xcf},
> + {0x5b05, 0x6c},
> + {0x5e00, 0x00},
> + {0x5e10, 0xfc}
> +};
> +
> static const struct ov8856_reg mode_1640x1232_regs[] = {
> {0x3000, 0x20},
> {0x3003, 0x08},
> @@ -506,6 +732,208 @@ static const struct ov8856_reg mode_1640x1232_regs[] = {
> {0x5e00, 0x00}
> };
>
> +static const struct ov8856_reg mode_1632x1224_regs[] = {
> + {0x0103, 0x01},
> + {0x0302, 0x3c},
> + {0x0303, 0x01},
> + {0x031e, 0x0c},
> + {0x3000, 0x00},
> + {0x300e, 0x00},
> + {0x3010, 0x00},
> + {0x3015, 0x84},
> + {0x3018, 0x72},
> + {0x3021, 0x23},
> + {0x3033, 0x24},
> + {0x3500, 0x00},
> + {0x3501, 0x4c},
> + {0x3502, 0xe0},
> + {0x3503, 0x08},
> + {0x3505, 0x83},
> + {0x3508, 0x01},
> + {0x3509, 0x80},
> + {0x350c, 0x00},
> + {0x350d, 0x80},
> + {0x350e, 0x04},
> + {0x350f, 0x00},
> + {0x3510, 0x00},
> + {0x3511, 0x02},
> + {0x3512, 0x00},
> + {0x3600, 0x72},
> + {0x3601, 0x40},
> + {0x3602, 0x30},
> + {0x3610, 0xc5},
> + {0x3611, 0x58},
> + {0x3612, 0x5c},
> + {0x3613, 0xca},
> + {0x3614, 0x60},
> + {0x3628, 0xff},
> + {0x3629, 0xff},
> + {0x362a, 0xff},
> + {0x3633, 0x10},
> + {0x3634, 0x10},
> + {0x3635, 0x10},
> + {0x3636, 0x10},
> + {0x3663, 0x08},
> + {0x3669, 0x34},
> + {0x366d, 0x00},
> + {0x366e, 0x08},
> + {0x3706, 0x86},
> + {0x370b, 0x7e},
> + {0x3714, 0x27},
> + {0x3730, 0x12},
> + {0x3733, 0x10},
> + {0x3764, 0x00},
> + {0x3765, 0x00},
> + {0x3769, 0x62},
> + {0x376a, 0x2a},
> + {0x376b, 0x30},
> + {0x3780, 0x00},
> + {0x3781, 0x24},
> + {0x3782, 0x00},
> + {0x3783, 0x23},
> + {0x3798, 0x2f},
> + {0x37a1, 0x60},
> + {0x37a8, 0x6a},
> + {0x37ab, 0x3f},
> + {0x37c2, 0x14},
> + {0x37c3, 0xf1},
> + {0x37c9, 0x80},
> + {0x37cb, 0x16},
> + {0x37cc, 0x16},
> + {0x37cd, 0x16},
> + {0x37ce, 0x16},
> + {0x3800, 0x00},
> + {0x3801, 0x00},
> + {0x3802, 0x00},
> + {0x3803, 0x0c},
> + {0x3804, 0x0c},
> + {0x3805, 0xdf},
> + {0x3806, 0x09},
> + {0x3807, 0xa3},
> + {0x3808, 0x06},
> + {0x3809, 0x60},
> + {0x380a, 0x04},
> + {0x380b, 0xc8},
> + {0x380c, 0x07},
> + {0x380d, 0x8c},
> + {0x380e, 0x09},
> + {0x380f, 0xb2},
> + {0x3810, 0x00},
> + {0x3811, 0x02},
> + {0x3812, 0x00},
> + {0x3813, 0x02},
> + {0x3814, 0x03},
> + {0x3815, 0x01},
> + {0x3816, 0x00},
> + {0x3817, 0x00},
> + {0x3818, 0x00},
> + {0x3819, 0x00},
> + {0x3820, 0x80},
> + {0x3821, 0x47},
> + {0x382a, 0x03},
> + {0x382b, 0x01},
> + {0x3830, 0x06},
> + {0x3836, 0x02},
> + {0x3862, 0x04},
> + {0x3863, 0x08},
> + {0x3cc0, 0x33},
> + {0x3d85, 0x17},
> + {0x3d8c, 0x73},
> + {0x3d8d, 0xde},
> + {0x4001, 0xe0},
> + {0x4003, 0x40},
> + {0x4008, 0x00},
> + {0x4009, 0x05},
> + {0x400a, 0x00},
> + {0x400b, 0x84},
> + {0x400f, 0x80},
> + {0x4010, 0xf0},
> + {0x4011, 0xff},
> + {0x4012, 0x02},
> + {0x4013, 0x01},
> + {0x4014, 0x01},
> + {0x4015, 0x01},
> + {0x4042, 0x00},
> + {0x4043, 0x80},
> + {0x4044, 0x00},
> + {0x4045, 0x80},
> + {0x4046, 0x00},
> + {0x4047, 0x80},
> + {0x4048, 0x00},
> + {0x4049, 0x80},
> + {0x4041, 0x03},
> + {0x404c, 0x20},
> + {0x404d, 0x00},
> + {0x404e, 0x20},
> + {0x4203, 0x80},
> + {0x4307, 0x30},
> + {0x4317, 0x00},
> + {0x4502, 0x50},
> + {0x4503, 0x08},
> + {0x4601, 0x80},
> + {0x4800, 0x44},
> + {0x4816, 0x53},
> + {0x481b, 0x50},
> + {0x481f, 0x27},
> + {0x4823, 0x3c},
> + {0x482b, 0x00},
> + {0x4831, 0x66},
> + {0x4837, 0x16},
> + {0x483c, 0x0f},
> + {0x484b, 0x05},
> + {0x5000, 0x77},
> + {0x5001, 0x0a},
> + {0x5003, 0xc8},
> + {0x5004, 0x04},
> + {0x5006, 0x00},
> + {0x5007, 0x00},
> + {0x502e, 0x03},
> + {0x5030, 0x41},
> + {0x5795, 0x00},
> + {0x5796, 0x10},
> + {0x5797, 0x10},
> + {0x5798, 0x73},
> + {0x5799, 0x73},
> + {0x579a, 0x00},
> + {0x579b, 0x28},
> + {0x579c, 0x00},
> + {0x579d, 0x16},
> + {0x579e, 0x06},
> + {0x579f, 0x20},
> + {0x57a0, 0x04},
> + {0x57a1, 0xa0},
> + {0x5780, 0x14},
> + {0x5781, 0x0f},
> + {0x5782, 0x44},
> + {0x5783, 0x02},
> + {0x5784, 0x01},
> + {0x5785, 0x01},
> + {0x5786, 0x00},
> + {0x5787, 0x04},
> + {0x5788, 0x02},
> + {0x5789, 0x0f},
> + {0x578a, 0xfd},
> + {0x578b, 0xf5},
> + {0x578c, 0xf5},
> + {0x578d, 0x03},
> + {0x578e, 0x08},
> + {0x578f, 0x0c},
> + {0x5790, 0x08},
> + {0x5791, 0x04},
> + {0x5792, 0x00},
> + {0x5793, 0x52},
> + {0x5794, 0xa3},
> + {0x59f8, 0x3d},
> + {0x5a08, 0x02},
> + {0x5b00, 0x02},
> + {0x5b01, 0x10},
> + {0x5b02, 0x03},
> + {0x5b03, 0xcf},
> + {0x5b05, 0x6c},
> + {0x5e00, 0x00},
> + {0x5e10, 0xfc}
> +};
> +
> static const char * const ov8856_test_pattern_menu[] = {
> "Disabled",
> "Standard Color Bar",
> @@ -548,6 +976,18 @@ static const struct ov8856_mode supported_modes[] = {
> .link_freq_index = OV8856_LINK_FREQ_720MBPS,
> },
> {
> + .width = 3264,
> + .height = 2448,
> + .hts = 1932,
> + .vts_def = 2482,
> + .vts_min = 2482,
> + .reg_list = {
> + .num_of_regs = ARRAY_SIZE(mode_3264x2448_regs),
> + .regs = mode_3264x2448_regs,
> + },
> + .link_freq_index = OV8856_LINK_FREQ_720MBPS,
> + },
> + {
> .width = 1640,
> .height = 1232,
> .hts = 3820,
> @@ -558,6 +998,18 @@ static const struct ov8856_mode supported_modes[] = {
> .regs = mode_1640x1232_regs,
> },
> .link_freq_index = OV8856_LINK_FREQ_360MBPS,
> + },
> + {
> + .width = 1632,
> + .height = 1224,
> + .hts = 1932,
> + .vts_def = 2482,
> + .vts_min = 2482,
> + .reg_list = {
> + .num_of_regs = ARRAY_SIZE(mode_1632x1224_regs),
> + .regs = mode_1632x1224_regs,
> + },
> + .link_freq_index = OV8856_LINK_FREQ_360MBPS,
> }
> };
>
> @@ -566,6 +1018,10 @@ struct ov8856 {
> struct media_pad pad;
> struct v4l2_ctrl_handler ctrl_handler;
>
> + struct clk *xvclk;
> + struct gpio_desc *reset_gpio;
> + struct regulator_bulk_data supplies[OV8856_NUM_SUPPLIES];
> +
> /* V4L2 Controls */
> struct v4l2_ctrl *link_freq;
> struct v4l2_ctrl *pixel_rate;
> @@ -576,6 +1032,9 @@ struct ov8856 {
> /* Current mode */
> const struct ov8856_mode *cur_mode;
>
> + /* module hardware version */
> + bool is_1B_module;

What other hardware versions are there, and what are the differences?

> +
> /* To serialize asynchronus callbacks */
> struct mutex mutex;
>
> @@ -696,6 +1155,24 @@ static int ov8856_test_pattern(struct ov8856 *ov8856, u32 pattern)
> OV8856_REG_VALUE_08BIT, pattern);
> }
>
> +static int ov8856_update_otp_reg(struct ov8856 *ov8856)
> +{
> + int ret;
> +
> + ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
> + OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING);
> + if (ret)
> + return ret;
> +
> + ret = ov8856_write_reg(ov8856, OV8856_OTP_REG_ONE,
> + OV8856_REG_VALUE_08BIT, OV8856_MODE_STANDBY);
> + if (ret)
> + return ret;
> +
> + return ov8856_write_reg(ov8856, OV8856_OTP_REG_TWO,
> + OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING);
> +}

What does this do?

> +
> static int ov8856_set_ctrl(struct v4l2_ctrl *ctrl)
> {
> struct ov8856 *ov8856 = container_of(ctrl->handler,
> @@ -825,7 +1302,13 @@ static void ov8856_update_pad_format(const struct ov8856_mode *mode,
> {
> fmt->width = mode->width;
> fmt->height = mode->height;
> - fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
> +
> + /* Bayer Order is determined by image resolution */

Ouch.

This rather looks like a side effect of vertical cropping. How about
either cropping one line above or below, to keep the same Bayer order?

The driver is based on register lists that heavily restricts the
possibilities of configuring the sensor. The alternative, should more
free-form configuration be enabled, would be to expose the cropping
capability to the user --- as well as binning.

> + if (fmt->width == 3264 || fmt->width == 1632)
> + fmt->code = MEDIA_BUS_FMT_SBGGR10_1X10;
> + else
> + fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
> +
> fmt->field = V4L2_FIELD_NONE;
> }
>
> @@ -850,6 +1333,17 @@ static int ov8856_start_streaming(struct ov8856 *ov8856)
> return ret;
> }
>
> + /* update R3614 for 1B module */
> + if (ov8856->is_1B_module) {
> + ret = ov8856_write_reg(ov8856, OV8856_CLK_REG,
> + OV8856_REG_VALUE_08BIT,
> + OV8856_CLK_REG_1B_VAL);
> + if (ret) {
> + dev_err(&client->dev, "failed to set R3614");
> + return ret;
> + }
> + }
> +
> ret = __v4l2_ctrl_handler_setup(ov8856->sd.ctrl_handler);
> if (ret)
> return ret;
> @@ -882,6 +1376,8 @@ static int ov8856_set_stream(struct v4l2_subdev *sd, int enable)
> if (ov8856->streaming == enable)
> return 0;
>
> + dev_dbg(&client->dev, "hardware version: (%d)\n", ov8856->is_1B_module);
> +
> mutex_lock(&ov8856->mutex);
> if (enable) {
> ret = pm_runtime_get_sync(&client->dev);
> @@ -908,6 +1404,54 @@ static int ov8856_set_stream(struct v4l2_subdev *sd, int enable)
> return ret;
> }
>
> +/* Calculate the delay in us by clock rate and clock cycles */
> +static inline u32 ov8856_cal_delay(u32 cycles)
> +{
> + return DIV_ROUND_UP(cycles, OV8856_XVCLK_FREQ / 1000 / 1000);

The frequency is rounded down. As it is used to calculate a delay needed,
rounding up should be done for the frequency, too.

> +}
> +
> +static int __ov8856_power_on(struct ov8856 *ov8856)
> +{
> + int ret;
> + u32 delay_us;
> + struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
> +
> + ret = clk_prepare_enable(ov8856->xvclk);
> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to enable xvclk\n");
> + return ret;
> + }
> +
> + gpiod_set_value_cansleep(ov8856->reset_gpio, 1);
> +
> + ret = regulator_bulk_enable(OV8856_NUM_SUPPLIES, ov8856->supplies);
> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to enable regulators\n");
> + goto disable_clk;
> + }
> +
> + gpiod_set_value_cansleep(ov8856->reset_gpio, 0);
> +
> + /* 8192 cycles prior to first SCCB transaction */
> + delay_us = ov8856_cal_delay(8192);
> + usleep_range(delay_us * 2, delay_us * 4);

Why multiply by 2?

Note that the driver still needs to work even if the resources aren't
visible to the software. That's the case e.g. on ACPI based systems.

> +
> + return 0;
> +
> +disable_clk:
> + clk_disable_unprepare(ov8856->xvclk);
> +
> + return ret;
> +}
> +
> +static void __ov8856_power_off(struct ov8856 *ov8856)
> +{
> + clk_disable_unprepare(ov8856->xvclk);
> + gpiod_set_value_cansleep(ov8856->reset_gpio, 1);
> +
> + regulator_bulk_disable(OV8856_NUM_SUPPLIES, ov8856->supplies);
> +}
> +
> static int __maybe_unused ov8856_suspend(struct device *dev)
> {
> struct i2c_client *client = to_i2c_client(dev);
> @@ -915,8 +1459,8 @@ static int __maybe_unused ov8856_suspend(struct device *dev)
> struct ov8856 *ov8856 = to_ov8856(sd);
>
> mutex_lock(&ov8856->mutex);
> - if (ov8856->streaming)
> - ov8856_stop_streaming(ov8856);

This seems like an unrelated change.

> +
> + __ov8856_power_off(ov8856);
>
> mutex_unlock(&ov8856->mutex);
>
> @@ -1089,6 +1633,20 @@ static int ov8856_identify_module(struct ov8856 *ov8856)
> return -ENXIO;
> }
>
> + /* set R3614 to distinguish harward versions */
> + ret = ov8856_update_otp_reg(ov8856);
> + if (ret) {
> + dev_err(&client->dev, "failed to set otp register");
> + return ret;
> + }
> +
> + ret = ov8856_read_reg(ov8856, OV8856_OTP_REG,
> + OV8856_REG_VALUE_08BIT, &val);
> + if (ret)
> + return ret;
> +
> + ov8856->is_1B_module = (val == OV8856_1B_MODULE) ? 1 : 0;
> +
> return 0;
> }
>
> @@ -1164,11 +1722,27 @@ static int ov8856_remove(struct i2c_client *client)
> media_entity_cleanup(&sd->entity);
> v4l2_ctrl_handler_free(sd->ctrl_handler);
> pm_runtime_disable(&client->dev);
> + if (!pm_runtime_status_suspended(&client->dev))
> + __ov8856_power_off(ov8856);
> + pm_runtime_set_suspended(&client->dev);
> mutex_destroy(&ov8856->mutex);
>
> return 0;
> }
>
> +static int ov8856_configure_regulators(struct ov8856 *ov8856)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
> + int i;

unsigned int

> +
> + for (i = 0; i < OV8856_NUM_SUPPLIES; i++)
> + ov8856->supplies[i].supply = ov8856_supply_names[i];
> +
> + return devm_regulator_bulk_get(&client->dev,
> + OV8856_NUM_SUPPLIES,
> + ov8856->supplies);

Remember to put the regulators, too.

> +}
> +
> static int ov8856_probe(struct i2c_client *client)
> {
> struct ov8856 *ov8856;
> @@ -1186,6 +1760,40 @@ static int ov8856_probe(struct i2c_client *client)
> return -ENOMEM;
>
> v4l2_i2c_subdev_init(&ov8856->sd, client, &ov8856_subdev_ops);
> +
> + ov8856->xvclk = devm_clk_get(&client->dev, "xvclk");
> + if (IS_ERR(ov8856->xvclk)) {
> + dev_err(&client->dev, "Failed to get xvclk\n");
> + return -EINVAL;
> + }
> +
> + ret = clk_set_rate(ov8856->xvclk, OV8856_XVCLK_FREQ);
> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to set xvclk rate (24MHz)\n");
> + return ret;
> + }
> + if (clk_get_rate(ov8856->xvclk) != OV8856_XVCLK_FREQ)
> + dev_warn(&client->dev,
> + "xvclk mismatched, modes are based on 24MHz\n");
> +
> + ov8856->reset_gpio = devm_gpiod_get(&client->dev,
> + "reset",

Fits on the previous line.

> + GPIOD_OUT_LOW);
> + if (IS_ERR(ov8856->reset_gpio)) {
> + dev_err(&client->dev, "Failed to get reset-gpios\n");
> + return -EINVAL;
> + }
> +
> + ret = ov8856_configure_regulators(ov8856);
> + if (ret) {
> + dev_err(&client->dev, "Failed to get power regulators\n");
> + return ret;
> + }
> +
> + ret = __ov8856_power_on(ov8856);
> + if (ret)
> + goto probe_error_v4l2_ctrl_handler_free;
> +
> ret = ov8856_identify_module(ov8856);
> if (ret) {
> dev_err(&client->dev, "failed to find sensor: %d", ret);
> @@ -1251,11 +1859,21 @@ static const struct acpi_device_id ov8856_acpi_ids[] = {
> MODULE_DEVICE_TABLE(acpi, ov8856_acpi_ids);
> #endif
>
> +#if IS_ENABLED(CONFIG_OF)
> +static const struct of_device_id ov8856_of_match[] = {
> + { .compatible = "ovti,ov8856" },
> + {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, ov8856_of_match);
> +#endif
> +
> static struct i2c_driver ov8856_i2c_driver = {
> .driver = {
> .name = "ov8856",
> .pm = &ov8856_pm_ops,
> .acpi_match_table = ACPI_PTR(ov8856_acpi_ids),
> + .of_match_table = of_match_ptr(ov8856_of_match),
> },
> .probe_new = ov8856_probe,
> .remove = ov8856_remove,

--
Regards,

Sakari Ailus