[2/2] media: i2c: Add support for the OV5648 image sensor

The OV5648 is a 5 Mpx CMOS image sensor, connected via MIPI CSI-2
in a two-lane configuration.

Most of the features of the hardware are supported, including:
- Auto and manual exposition/gain
- Auto and manual white balance
- Horizontal and vertical flip
- Test patterns

But the following are still missing:
- Debanding, based on power source frequency;
- Exposition setting correlated to time units.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
 drivers/media/i2c/Kconfig  |   14 +
 drivers/media/i2c/Makefile |    1 +
 drivers/media/i2c/ov5648.c | 2680 ++++++++++++++++++++++++++++++++++++
 3 files changed, 2695 insertions(+)
 create mode 100644 drivers/media/i2c/ov5648.c

Hi Paul,

Thank you for the patchset.

It's nice to see a driver that is not based on register lists --- most are.

On Fri, Oct 23, 2020 at 07:49:44PM +0200, Paul Kocialkowski wrote:
> The OV5648 is a 5 Mpx CMOS image sensor, connected via MIPI CSI-2
> in a two-lane configuration.

One or two, I guess?

> 
> Most of the features of the hardware are supported, including:
> - Auto and manual exposition/gain
> - Auto and manual white balance
> - Horizontal and vertical flip
> - Test patterns
> 
> But the following are still missing:
> - Debanding, based on power source frequency;
> - Exposition setting correlated to time units.
> 
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> ---
>  drivers/media/i2c/Kconfig  |   14 +
>  drivers/media/i2c/Makefile |    1 +
>  drivers/media/i2c/ov5648.c | 2680 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 2695 insertions(+)
>  create mode 100644 drivers/media/i2c/ov5648.c
> 
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 48ae60a2c603..49f4e261c48e 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -922,6 +922,20 @@ config VIDEO_OV5647
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called ov5647.
>  
> +config VIDEO_OV5648
> +	tristate "OmniVision OV5648 sensor support"
> +	depends on OF
> +	depends on I2C && VIDEO_V4L2
> +	select MEDIA_CONTROLLER
> +	select VIDEO_V4L2_SUBDEV_API
> +	select V4L2_FWNODE
> +	help
> +	  This is a Video4Linux2 sensor driver for the OmniVision
> +	  OV5648 camera.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ov5648.
> +
>  config VIDEO_OV6650
>  	tristate "OmniVision OV6650 sensor support"
>  	depends on I2C && VIDEO_V4L2
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index f0a77473979d..15d4d6382582 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -71,6 +71,7 @@ obj-$(CONFIG_VIDEO_OV2740) += ov2740.o
>  obj-$(CONFIG_VIDEO_OV5640) += ov5640.o
>  obj-$(CONFIG_VIDEO_OV5645) += ov5645.o
>  obj-$(CONFIG_VIDEO_OV5647) += ov5647.o
> +obj-$(CONFIG_VIDEO_OV5648) += ov5648.o
>  obj-$(CONFIG_VIDEO_OV5670) += ov5670.o
>  obj-$(CONFIG_VIDEO_OV5675) += ov5675.o
>  obj-$(CONFIG_VIDEO_OV5695) += ov5695.o
> diff --git a/drivers/media/i2c/ov5648.c b/drivers/media/i2c/ov5648.c
> new file mode 100644
> index 000000000000..2c3c7f48de2f
> --- /dev/null
> +++ b/drivers/media/i2c/ov5648.c
> @@ -0,0 +1,2680 @@
> +/*
> + * OmniVision OV5648 V4L2 driver
> + *
> + * Copyright (C) 2020 Bootlin
> + * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation version 2.
> + *
> + * This program is distributed .as is. WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.

Please use SPDX tags instead.

> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/videodev2.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-image-sizes.h>
> +#include <media/v4l2-mediabus.h>
> +
> +/* Clock rate */
> +
> +#define OV5648_XVCLK_RATE			24000000
> +
> +/* Register definitions */
> +
> +/* System */
> +
> +#define OV5648_SW_STANDBY_REG			0x100
> +#define OV5648_SW_STANDBY_STREAM_ON		BIT(0)
> +
> +#define OV5648_SW_RESET_REG			0x103
> +#define OV5648_SW_RESET_RESET			BIT(0)
> +
> +#define OV5648_PAD_OEN0_REG			0x3000
> +#define OV5648_PAD_OEN1_REG			0x3001
> +#define OV5648_PAD_OEN2_REG			0x3002
> +#define OV5648_PAD_OUT0_REG			0x3008
> +#define OV5648_PAD_OUT1_REG			0x3009
> +
> +#define OV5648_CHIP_ID_H_REG			0x300a
> +#define OV5648_CHIP_ID_H_VALUE			0x56
> +#define OV5648_CHIP_ID_L_REG			0x300b
> +#define OV5648_CHIP_ID_L_VALUE			0x48
> +
> +#define OV5648_PAD_OUT2_REG			0x300d
> +#define OV5648_PAD_SEL0_REG			0x300e
> +#define OV5648_PAD_SEL1_REG			0x300f
> +#define OV5648_PAD_SEL2_REG			0x3010
> +#define OV5648_PAD_PK_REG			0x3011
> +#define OV5648_PAD_PK_PD_DATO_EN		BIT(7)
> +#define OV5648_PAD_PK_DRIVE_STRENGTH_1X		(0 << 5)
> +#define OV5648_PAD_PK_DRIVE_STRENGTH_2X		(2 << 5)
> +#define OV5648_PAD_PK_FREX_N			BIT(1)
> +
> +#define OV5648_A_PWC_PK_O0_REG			0x3013
> +#define OV5648_A_PWC_PK_O0_BP_REGULATOR_N	BIT(3)
> +#define OV5648_A_PWC_PK_O1_REG			0x3014
> +
> +#define OV5648_MIPI_PHY0_REG			0x3016
> +#define OV5648_MIPI_PHY1_REG			0x3017
> +#define OV5648_MIPI_SC_CTRL0_REG		0x3018
> +#define OV5648_MIPI_SC_CTRL0_MIPI_LANES(v)	(((v) << 5) & GENMASK(7, 5))
> +#define OV5648_MIPI_SC_CTRL0_PHY_HS_TX_PD	BIT(4)
> +#define OV5648_MIPI_SC_CTRL0_PHY_LP_RX_PD	BIT(3)
> +#define OV5648_MIPI_SC_CTRL0_MIPI_EN		BIT(2)
> +#define OV5648_MIPI_SC_CTRL0_MIPI_SUSP		BIT(1)
> +#define OV5648_MIPI_SC_CTRL0_LANE_DIS_OP	BIT(0)
> +#define OV5648_MIPI_SC_CTRL1_REG		0x3019
> +#define OV5648_MISC_CTRL0_REG			0x3021
> +#define OV5648_MIPI_SC_CTRL2_REG		0x3022
> +#define OV5648_SUB_ID_REG			0x302a
> +
> +#define OV5648_PLL_CTRL0_REG			0x3034
> +#define OV5648_PLL_CTRL0_PLL_CHARGE_PUMP(v)	(((v) << 4) & GENMASK(6, 4))
> +#define OV5648_PLL_CTRL0_BITS(v)		((v) & GENMASK(3, 0))
> +#define OV5648_PLL_CTRL1_REG			0x3035
> +#define OV5648_PLL_CTRL1_SYS_DIV(v)		(((v) << 4) & GENMASK(7, 4))
> +#define OV5648_PLL_CTRL1_MIPI_DIV(v)		((v) & GENMASK(3, 0))
> +#define OV5648_PLL_MUL_REG			0x3036
> +#define OV5648_PLL_MUL(v)			((v) & GENMASK(7, 0))
> +#define OV5648_PLL_DIV_REG			0x3037
> +#define OV5648_PLL_DIV_ROOT_DIV(v)		((((v) - 1) << 4) & BIT(4))
> +#define OV5648_PLL_DIV_PLL_PRE_DIV(v)		((v) & GENMASK(3, 0))
> +#define OV5648_PLL_DEBUG_REG			0x3038
> +#define OV5648_PLL_BYPASS_REG			0x3039
> +
> +#define OV5648_PLLS_BYPASS_REG			0x303a
> +#define OV5648_PLLS_MUL_REG			0x303b
> +#define OV5648_PLLS_MUL(v)			((v) & GENMASK(4, 0))
> +#define OV5648_PLLS_CTRL_REG			0x303c
> +#define OV5648_PLLS_CTRL_PLL_CHARGE_PUMP(v)	(((v) << 4) & GENMASK(6, 4))
> +#define OV5648_PLLS_CTRL_SYS_DIV(v)		((v) & GENMASK(3, 0))
> +#define OV5648_PLLS_DIV_REG			0x303d
> +#define OV5648_PLLS_DIV_PLLS_PRE_DIV(v)		(((v) << 4) & GENMASK(5, 4))
> +#define OV5648_PLLS_DIV_PLLS_DIV_R(v)		((((v) - 1) << 2) & BIT(2))
> +#define OV5648_PLLS_DIV_PLLS_SEL_DIV(v)		((v) & GENMASK(1, 0))
> +
> +#define OV5648_SRB_CTRL_REG			0x3106
> +#define OV5648_SRB_CTRL_SCLK_DIV(v)		(((v) << 2) & GENMASK(3, 2))
> +#define OV5648_SRB_CTRL_RESET_ARBITER_EN	BIT(1)
> +#define OV5648_SRB_CTRL_SCLK_ARBITER_EN		BIT(0)
> +
> +/* Group Hold */
> +
> +#define OV5648_GROUP_ADR0_REG			0x3200
> +#define OV5648_GROUP_ADR1_REG			0x3201
> +#define OV5648_GROUP_ADR2_REG			0x3202
> +#define OV5648_GROUP_ADR3_REG			0x3203
> +#define OV5648_GROUP_LEN0_REG			0x3204
> +#define OV5648_GROUP_LEN1_REG			0x3205
> +#define OV5648_GROUP_LEN2_REG			0x3206
> +#define OV5648_GROUP_LEN3_REG			0x3207
> +#define OV5648_GROUP_ACCESS_REG			0x3208
> +
> +/* Exposure/gain/banding */
> +
> +#define OV5648_EXPOSURE_CTRL_HH_REG		0x3500
> +#define OV5648_EXPOSURE_CTRL_HH(v)		(((v) & GENMASK(19, 16)) >> 16)
> +#define OV5648_EXPOSURE_CTRL_HH_VALUE(v)	(((v) << 16) & GENMASK(19, 16))
> +#define OV5648_EXPOSURE_CTRL_H_REG		0x3501
> +#define OV5648_EXPOSURE_CTRL_H(v)		(((v) & GENMASK(15, 8)) >> 8)
> +#define OV5648_EXPOSURE_CTRL_H_VALUE(v)		(((v) << 8) & GENMASK(15, 8))
> +#define OV5648_EXPOSURE_CTRL_L_REG		0x3502
> +#define OV5648_EXPOSURE_CTRL_L(v)		((v) & GENMASK(7, 0))
> +#define OV5648_EXPOSURE_CTRL_L_VALUE(v)		((v) & GENMASK(7, 0))
> +#define OV5648_MANUAL_CTRL_REG			0x3503
> +#define OV5648_MANUAL_CTRL_FRAME_DELAY(v)	(((v) << 4) & GENMASK(5, 4))
> +#define OV5648_MANUAL_CTRL_AGC_MANUAL_EN	BIT(1)
> +#define OV5648_MANUAL_CTRL_AEC_MANUAL_EN	BIT(0)
> +#define OV5648_GAIN_CTRL_H_REG			0x350a
> +#define OV5648_GAIN_CTRL_H(v)			(((v) & GENMASK(9, 8)) >> 8)
> +#define OV5648_GAIN_CTRL_H_VALUE(v)		(((v) << 8) & GENMASK(9, 8))
> +#define OV5648_GAIN_CTRL_L_REG			0x350b
> +#define OV5648_GAIN_CTRL_L(v)			((v) & GENMASK(7, 0))
> +#define OV5648_GAIN_CTRL_L_VALUE(v)		((v) & GENMASK(7, 0))
> +
> +#define OV5648_ANALOG_CTRL0_REG_BASE		0x3600
> +#define OV5648_ANALOG_CTRL1_REG_BASE		0x3700
> +
> +#define OV5648_AEC_CTRL0_REG			0x3a00
> +#define OV5648_AEC_CTRL0_DEBUG			BIT(6)
> +#define OV5648_AEC_CTRL0_DEBAND_EN		BIT(5)
> +#define OV5648_AEC_CTRL0_DEBAND_LOW_LIMIT_EN	BIT(4)
> +#define OV5648_AEC_CTRL0_START_SEL_EN		BIT(3)
> +#define OV5648_AEC_CTRL0_NIGHT_MODE_EN		BIT(2)
> +#define OV5648_AEC_CTRL0_FREEZE_EN		BIT(0)
> +#define OV5648_EXPOSURE_MIN_REG			0x3a01
> +#define OV5648_EXPOSURE_MAX_60_H_REG		0x3a02
> +#define OV5648_EXPOSURE_MAX_60_L_REG		0x3a03
> +#define OV5648_AEC_CTRL5_REG			0x3a05
> +#define OV5648_AEC_CTRL6_REG			0x3a06
> +#define OV5648_AEC_CTRL7_REG			0x3a07
> +#define OV5648_BANDING_STEP_50_H_REG		0x3a08
> +#define OV5648_BANDING_STEP_50_L_REG		0x3a09
> +#define OV5648_BANDING_STEP_60_H_REG		0x3a0a
> +#define OV5648_BANDING_STEP_60_L_REG		0x3a0b
> +#define OV5648_AEC_CTRLC_REG			0x3a0c
> +#define OV5648_BANDING_MAX_60_REG		0x3a0d
> +#define OV5648_BANDING_MAX_50_REG		0x3a0e
> +#define OV5648_WPT_REG				0x3a0f
> +#define OV5648_BPT_REG				0x3a10
> +#define OV5648_VPT_HIGH_REG			0x3a11
> +#define OV5648_AVG_MANUAL_REG			0x3a12
> +#define OV5648_PRE_GAIN_REG			0x3a13
> +#define OV5648_EXPOSURE_MAX_50_H_REG		0x3a14
> +#define OV5648_EXPOSURE_MAX_50_L_REG		0x3a15
> +#define OV5648_GAIN_BASE_NIGHT_REG		0x3a17
> +#define OV5648_AEC_GAIN_CEILING_H_REG		0x3a18
> +#define OV5648_AEC_GAIN_CEILING_L_REG		0x3a19
> +#define OV5648_DIFF_MAX_REG			0x3a1a
> +#define OV5648_WPT2_REG				0x3a1b
> +#define OV5648_LED_ADD_ROW_H_REG		0x3a1c
> +#define OV5648_LED_ADD_ROW_L_REG		0x3a1d
> +#define OV5648_BPT2_REG				0x3a1e
> +#define OV5648_VPT_LOW_REG			0x3a1f
> +#define OV5648_AEC_CTRL20_REG			0x3a20
> +#define OV5648_AEC_CTRL21_REG			0x3a21
> +
> +#define OV5648_AVG_START_X_H_REG		0x5680
> +#define OV5648_AVG_START_X_L_REG		0x5681
> +#define OV5648_AVG_START_Y_H_REG		0x5682
> +#define OV5648_AVG_START_Y_L_REG		0x5683
> +#define OV5648_AVG_WINDOW_X_H_REG		0x5684
> +#define OV5648_AVG_WINDOW_X_L_REG		0x5685
> +#define OV5648_AVG_WINDOW_Y_H_REG		0x5686
> +#define OV5648_AVG_WINDOW_Y_L_REG		0x5687
> +#define OV5648_AVG_WEIGHT00_REG			0x5688
> +#define OV5648_AVG_WEIGHT01_REG			0x5689
> +#define OV5648_AVG_WEIGHT02_REG			0x568a
> +#define OV5648_AVG_WEIGHT03_REG			0x568b
> +#define OV5648_AVG_WEIGHT04_REG			0x568c
> +#define OV5648_AVG_WEIGHT05_REG			0x568d
> +#define OV5648_AVG_WEIGHT06_REG			0x568e
> +#define OV5648_AVG_WEIGHT07_REG			0x568f
> +#define OV5648_AVG_CTRL10_REG			0x5690
> +#define OV5648_AVG_WEIGHT_SUM_REG		0x5691
> +#define OV5648_AVG_READOUT_REG			0x5693
> +
> +#define OV5648_DIG_CTRL0_REG			0x5a00
> +#define OV5648_DIG_COMP_MAN_H_REG		0x5a02
> +#define OV5648_DIG_COMP_MAN_L_REG		0x5a03
> +
> +#define OV5648_GAINC_MAN_H_REG			0x5a20
> +#define OV5648_GAINC_MAN_L_REG			0x5a21
> +#define OV5648_GAINC_DGC_MAN_H_REG		0x5a22
> +#define OV5648_GAINC_DGC_MAN_L_REG		0x5a23
> +#define OV5648_GAINC_CTRL0_REG			0x5a24
> +
> +#define OV5648_GAINF_ANA_NUM_REG		0x5a40
> +#define OV5648_GAINF_DIG_GAIN_REG		0x5a41
> +
> +/* Timing */
> +
> +#define OV5648_CROP_START_X_H_REG		0x3800
> +#define OV5648_CROP_START_X_H(v)		(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_CROP_START_X_L_REG		0x3801
> +#define OV5648_CROP_START_X_L(v)		((v) & GENMASK(7, 0))
> +#define OV5648_CROP_START_Y_H_REG		0x3802
> +#define OV5648_CROP_START_Y_H(v)		(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_CROP_START_Y_L_REG		0x3803
> +#define OV5648_CROP_START_Y_L(v)		((v) & GENMASK(7, 0))
> +#define OV5648_CROP_END_X_H_REG			0x3804
> +#define OV5648_CROP_END_X_H(v)			(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_CROP_END_X_L_REG			0x3805
> +#define OV5648_CROP_END_X_L(v)			((v) & GENMASK(7, 0))
> +#define OV5648_CROP_END_Y_H_REG			0x3806
> +#define OV5648_CROP_END_Y_H(v)			(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_CROP_END_Y_L_REG			0x3807
> +#define OV5648_CROP_END_Y_L(v)			((v) & GENMASK(7, 0))
> +#define OV5648_OUTPUT_SIZE_X_H_REG		0x3808
> +#define OV5648_OUTPUT_SIZE_X_H(v)		(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_OUTPUT_SIZE_X_L_REG		0x3809
> +#define OV5648_OUTPUT_SIZE_X_L(v)		((v) & GENMASK(7, 0))
> +#define OV5648_OUTPUT_SIZE_Y_H_REG		0x380a
> +#define OV5648_OUTPUT_SIZE_Y_H(v)		(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_OUTPUT_SIZE_Y_L_REG		0x380b
> +#define OV5648_OUTPUT_SIZE_Y_L(v)		((v) & GENMASK(7, 0))
> +#define OV5648_HTS_H_REG			0x380c
> +#define OV5648_HTS_H(v)				(((v) & GENMASK(12, 8)) >> 8)
> +#define OV5648_HTS_L_REG			0x380d
> +#define OV5648_HTS_L(v)				((v) & GENMASK(7, 0))
> +#define OV5648_VTS_H_REG			0x380e
> +#define OV5648_VTS_H(v)				(((v) & GENMASK(15, 8)) >> 8)
> +#define OV5648_VTS_L_REG			0x380f
> +#define OV5648_VTS_L(v)				((v) & GENMASK(7, 0))
> +#define OV5648_OFFSET_X_H_REG			0x3810
> +#define OV5648_OFFSET_X_H(v)			(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_OFFSET_X_L_REG			0x3811
> +#define OV5648_OFFSET_X_L(v)			((v) & GENMASK(7, 0))
> +#define OV5648_OFFSET_Y_H_REG			0x3812
> +#define OV5648_OFFSET_Y_H(v)			(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_OFFSET_Y_L_REG			0x3813
> +#define OV5648_OFFSET_Y_L(v)			((v) & GENMASK(7, 0))
> +#define OV5648_SUB_INC_X_REG			0x3814
> +#define OV5648_SUB_INC_X_ODD(v)			(((v) << 4) & GENMASK(7, 4))
> +#define OV5648_SUB_INC_X_EVEN(v)		((v) & GENMASK(3, 0))
> +#define OV5648_SUB_INC_Y_REG			0x3815
> +#define OV5648_SUB_INC_Y_ODD(v)			(((v) << 4) & GENMASK(7, 4))
> +#define OV5648_SUB_INC_Y_EVEN(v)		((v) & GENMASK(3, 0))
> +#define OV5648_HSYNCST_H_REG			0x3816
> +#define OV5648_HSYNCST_H(v)			(((v) >> 8) & 0xf)
> +#define OV5648_HSYNCST_L_REG			0x3817
> +#define OV5648_HSYNCST_L(v)			((v) & GENMASK(7, 0))
> +#define OV5648_HSYNCW_H_REG			0x3818
> +#define OV5648_HSYNCW_H(v)			(((v) >> 8) & 0xf)
> +#define OV5648_HSYNCW_L_REG			0x3819
> +#define OV5648_HSYNCW_L(v)			((v) & GENMASK(7, 0))
> +
> +#define OV5648_TC20_REG				0x3820
> +#define OV5648_TC20_DEBUG			BIT(6)
> +#define OV5648_TC20_FLIP_VERT_ISP_EN		BIT(2)
> +#define OV5648_TC20_FLIP_VERT_SENSOR_EN		BIT(1)
> +#define OV5648_TC20_BINNING_VERT_EN		BIT(0)
> +#define OV5648_TC21_REG				0x3821
> +#define OV5648_TC21_FLIP_HORZ_ISP_EN		BIT(2)
> +#define OV5648_TC21_FLIP_HORZ_SENSOR_EN		BIT(1)
> +#define OV5648_TC21_BINNING_HORZ_EN		BIT(0)
> +
> +/* Strobe/exposure */
> +
> +#define OV5648_STROBE_REG			0x3b00
> +#define OV5648_FREX_EXP_HH_REG			0x3b01
> +#define OV5648_SHUTTER_DLY_H_REG		0x3b02
> +#define OV5648_SHUTTER_DLY_L_REG		0x3b03
> +#define OV5648_FREX_EXP_H_REG			0x3b04
> +#define OV5648_FREX_EXP_L_REG			0x3b05
> +#define OV5648_FREX_CTRL_REG			0x3b06
> +#define OV5648_FREX_MODE_SEL_REG		0x3b07
> +#define OV5648_FREX_MODE_SEL_FREX_SA1		BIT(4)
> +#define OV5648_FREX_MODE_SEL_FX1_FM_EN		BIT(3)
> +#define OV5648_FREX_MODE_SEL_FREX_INV		BIT(2)
> +#define OV5648_FREX_MODE_SEL_MODE1		0x0
> +#define OV5648_FREX_MODE_SEL_MODE2		0x1
> +#define OV5648_FREX_MODE_SEL_ROLLING		0x2
> +#define OV5648_FREX_EXP_REQ_REG			0x3b08
> +#define OV5648_FREX_SHUTTER_DLY_REG		0x3b09
> +#define OV5648_FREX_RST_LEN_REG			0x3b0a
> +#define OV5648_STROBE_WIDTH_HH_REG		0x3b0b
> +#define OV5648_STROBE_WIDTH_H_REG		0x3b0c
> +
> +/* OTP */
> +
> +#define OV5648_OTP_DATA_REG_BASE		0x3d00
> +#define OV5648_OTP_PROGRAM_CTRL_REG		0x3d80
> +#define OV5648_OTP_LOAD_CTRL_REG		0x3d81
> +
> +/* PSRAM */
> +
> +#define OV5648_PSRAM_CTRL1_REG			0x3f01
> +#define OV5648_PSRAM_CTRLF_REG			0x3f0f
> +
> +/* Black Level */
> +
> +#define OV5648_BLC_CTRL0_REG			0x4000
> +#define OV5648_BLC_CTRL1_REG			0x4001
> +#define OV5648_BLC_CTRL1_START_LINE(v)		((v) & GENMASK(5, 0))
> +#define OV5648_BLC_CTRL2_REG			0x4002
> +#define OV5648_BLC_CTRL2_AUTO_EN		BIT(6)
> +#define OV5648_BLC_CTRL2_RESET_FRAME_NUM(v)	((v) & GENMASK(5, 0))
> +#define OV5648_BLC_CTRL3_REG			0x4003
> +#define OV5648_BLC_LINE_NUM_REG			0x4004
> +#define OV5648_BLC_LINE_NUM(v)			((v) & GENMASK(7, 0))
> +#define OV5648_BLC_CTRL5_REG			0x4005
> +#define OV5648_BLC_CTRL5_UPDATE_EN		BIT(1)
> +#define OV5648_BLC_LEVEL_REG			0x4009
> +
> +/* Frame */
> +
> +#define OV5648_FRAME_CTRL_REG			0x4200
> +#define OV5648_FRAME_ON_NUM_REG			0x4201
> +#define OV5648_FRAME_OFF_NUM_REG		0x4202
> +
> +/* MIPI CSI-2 */
> +
> +#define OV5648_MIPI_CTRL0_REG			0x4800
> +#define OV5648_MIPI_CTRL0_CLK_LANE_AUTOGATE	BIT(5)
> +#define OV5648_MIPI_CTRL0_LANE_SYNC_EN		BIT(4)
> +#define OV5648_MIPI_CTRL0_LANE_SELECT_LANE1	0
> +#define OV5648_MIPI_CTRL0_LANE_SELECT_LANE2	BIT(3)
> +#define OV5648_MIPI_CTRL0_IDLE_LP00		0
> +#define OV5648_MIPI_CTRL0_IDLE_LP11		BIT(2)
> +
> +#define OV5648_MIPI_CTRL1_REG			0x4801
> +#define OV5648_MIPI_CTRL2_REG			0x4802
> +#define OV5648_MIPI_CTRL3_REG			0x4803
> +#define OV5648_MIPI_CTRL4_REG			0x4804
> +#define OV5648_MIPI_CTRL5_REG			0x4805
> +#define OV5648_MIPI_MAX_FRAME_COUNT_H_REG	0x4810
> +#define OV5648_MIPI_MAX_FRAME_COUNT_L_REG	0x4811
> +#define OV5648_MIPI_CTRL14_REG			0x4814
> +#define OV5648_MIPI_DT_SPKT_REG			0x4815
> +#define OV5648_MIPI_HS_ZERO_MIN_H_REG		0x4818
> +#define OV5648_MIPI_HS_ZERO_MIN_L_REG		0x4819
> +#define OV5648_MIPI_HS_TRAIN_MIN_H_REG		0x481a
> +#define OV5648_MIPI_HS_TRAIN_MIN_L_REG		0x481b
> +#define OV5648_MIPI_CLK_ZERO_MIN_H_REG		0x481c
> +#define OV5648_MIPI_CLK_ZERO_MIN_L_REG		0x481d
> +#define OV5648_MIPI_CLK_PREPARE_MIN_H_REG	0x481e
> +#define OV5648_MIPI_CLK_PREPARE_MIN_L_REG	0x481f
> +#define OV5648_MIPI_CLK_POST_MIN_H_REG		0x4820
> +#define OV5648_MIPI_CLK_POST_MIN_L_REG		0x4821
> +#define OV5648_MIPI_CLK_TRAIL_MIN_H_REG		0x4822
> +#define OV5648_MIPI_CLK_TRAIL_MIN_L_REG		0x4823
> +#define OV5648_MIPI_LPX_P_MIN_H_REG		0x4824
> +#define OV5648_MIPI_LPX_P_MIN_L_REG		0x4825
> +#define OV5648_MIPI_HS_PREPARE_MIN_H_REG	0x4826
> +#define OV5648_MIPI_HS_PREPARE_MIN_L_REG	0x4827
> +#define OV5648_MIPI_HS_EXIT_MIN_H_REG		0x4828
> +#define OV5648_MIPI_HS_EXIT_MIN_L_REG		0x4829
> +#define OV5648_MIPI_HS_ZERO_MIN_UI_REG		0x482a
> +#define OV5648_MIPI_HS_TRAIL_MIN_UI_REG		0x482b
> +#define OV5648_MIPI_CLK_ZERO_MIN_UI_REG		0x482c
> +#define OV5648_MIPI_CLK_PREPARE_MIN_UI_REG	0x482d
> +#define OV5648_MIPI_CLK_POST_MIN_UI_REG		0x482e
> +#define OV5648_MIPI_CLK_TRAIL_MIN_UI_REG	0x482f
> +#define OV5648_MIPI_LPX_P_MIN_UI_REG		0x4830
> +#define OV5648_MIPI_HS_PREPARE_MIN_UI_REG	0x4831
> +#define OV5648_MIPI_HS_EXIT_MIN_UI_REG		0x4832
> +#define OV5648_MIPI_REG_MIN_H_REG		0x4833
> +#define OV5648_MIPI_REG_MIN_L_REG		0x4834
> +#define OV5648_MIPI_REG_MAX_H_REG		0x4835
> +#define OV5648_MIPI_REG_MAX_L_REG		0x4836
> +#define OV5648_MIPI_PCLK_PERIOD_REG		0x4837
> +#define OV5648_MIPI_WKUP_DLY_REG		0x4838
> +#define OV5648_MIPI_LP_GPIO_REG			0x483b
> +#define OV5648_MIPI_SNR_PCLK_DIV_REG		0x4843
> +
> +/* ISP */
> +
> +#define OV5648_ISP_CTRL0_REG			0x5000
> +#define OV5648_ISP_CTRL0_BLACK_CORRECT_EN	BIT(2)
> +#define OV5648_ISP_CTRL0_WHITE_CORRECT_EN	BIT(1)
> +#define OV5648_ISP_CTRL1_REG			0x5001
> +#define OV5648_ISP_CTRL1_AWB_EN			BIT(0)
> +#define OV5648_ISP_CTRL2_REG			0x5002
> +#define OV5648_ISP_CTRL2_WIN_EN			BIT(6)
> +#define OV5648_ISP_CTRL2_OTP_EN			BIT(1)
> +#define OV5648_ISP_CTRL2_AWB_GAIN_EN		BIT(0)
> +#define OV5648_ISP_CTRL3_REG			0x5003
> +#define OV5648_ISP_CTRL3_BUF_EN			BIT(3)
> +#define OV5648_ISP_CTRL3_BIN_MAN_SET		BIT(2)
> +#define OV5648_ISP_CTRL3_BIN_AUTO_EN		BIT(1)
> +#define OV5648_ISP_CTRL4_REG			0x5004
> +#define OV5648_ISP_CTRL5_REG			0x5005
> +#define OV5648_ISP_CTRL6_REG			0x5006
> +#define OV5648_ISP_CTRL7_REG			0x5007
> +#define OV5648_ISP_MAN_OFFSET_X_H_REG		0x5008
> +#define OV5648_ISP_MAN_OFFSET_X_L_REG		0x5009
> +#define OV5648_ISP_MAN_OFFSET_Y_H_REG		0x500a
> +#define OV5648_ISP_MAN_OFFSET_Y_L_REG		0x500b
> +#define OV5648_ISP_MAN_WIN_OFFSET_X_H_REG	0x500c
> +#define OV5648_ISP_MAN_WIN_OFFSET_X_L_REG	0x500d
> +#define OV5648_ISP_MAN_WIN_OFFSET_Y_H_REG	0x500e
> +#define OV5648_ISP_MAN_WIN_OFFSET_Y_L_REG	0x500f
> +#define OV5648_ISP_MAN_WIN_OUTPUT_X_H_REG	0x5010
> +#define OV5648_ISP_MAN_WIN_OUTPUT_X_L_REG	0x5011
> +#define OV5648_ISP_MAN_WIN_OUTPUT_Y_H_REG	0x5012
> +#define OV5648_ISP_MAN_WIN_OUTPUT_Y_L_REG	0x5013
> +#define OV5648_ISP_MAN_INPUT_X_H_REG		0x5014
> +#define OV5648_ISP_MAN_INPUT_X_L_REG		0x5015
> +#define OV5648_ISP_MAN_INPUT_Y_H_REG		0x5016
> +#define OV5648_ISP_MAN_INPUT_Y_L_REG		0x5017
> +#define OV5648_ISP_CTRL18_REG			0x5018
> +#define OV5648_ISP_CTRL19_REG			0x5019
> +#define OV5648_ISP_CTRL1A_REG			0x501a
> +#define OV5648_ISP_CTRL1D_REG			0x501d
> +#define OV5648_ISP_CTRL1F_REG			0x501f
> +#define OV5648_ISP_CTRL1F_OUTPUT_EN		3
> +#define OV5648_ISP_CTRL25_REG			0x5025
> +
> +#define OV5648_ISP_CTRL3D_REG			0x503d
> +#define OV5648_ISP_CTRL3D_PATTERN_EN		BIT(7)
> +#define OV5648_ISP_CTRL3D_ROLLING_BAR_EN	BIT(6)
> +#define OV5648_ISP_CTRL3D_TRANSPARENT_MODE	BIT(5)
> +#define OV5648_ISP_CTRL3D_SQUARES_BW_MODE	BIT(4)
> +#define OV5648_ISP_CTRL3D_PATTERN_COLOR_BARS	0
> +#define OV5648_ISP_CTRL3D_PATTERN_RANDOM_DATA	1
> +#define OV5648_ISP_CTRL3D_PATTERN_COLOR_SQUARES	2
> +#define OV5648_ISP_CTRL3D_PATTERN_INPUT		3
> +
> +#define OV5648_ISP_CTRL3E_REG			0x503e
> +#define OV5648_ISP_CTRL4B_REG			0x504b
> +#define OV5648_ISP_CTRL4B_POST_BIN_H_EN		BIT(5)
> +#define OV5648_ISP_CTRL4B_POST_BIN_V_EN		BIT(4)
> +#define OV5648_ISP_CTRL4C_REG			0x504c
> +#define OV5648_ISP_CTRL57_REG			0x5057
> +#define OV5648_ISP_CTRL58_REG			0x5058
> +#define OV5648_ISP_CTRL59_REG			0x5059
> +
> +#define OV5648_ISP_WINDOW_START_X_H_REG		0x5980
> +#define OV5648_ISP_WINDOW_START_X_L_REG		0x5981
> +#define OV5648_ISP_WINDOW_START_Y_H_REG		0x5982
> +#define OV5648_ISP_WINDOW_START_Y_L_REG		0x5983
> +#define OV5648_ISP_WINDOW_WIN_X_H_REG		0x5984
> +#define OV5648_ISP_WINDOW_WIN_X_L_REG		0x5985
> +#define OV5648_ISP_WINDOW_WIN_Y_H_REG		0x5986
> +#define OV5648_ISP_WINDOW_WIN_Y_L_REG		0x5987
> +#define OV5648_ISP_WINDOW_MAN_REG		0x5988
> +
> +/* White Balance */
> +
> +#define OV5648_AWB_CTRL_REG			0x5180
> +#define OV5648_AWB_CTRL_FAST_AWB		BIT(6)
> +#define OV5648_AWB_CTRL_GAIN_FREEZE_EN		BIT(5)
> +#define OV5648_AWB_CTRL_SUM_FREEZE_EN		BIT(4)
> +#define OV5648_AWB_CTRL_GAIN_MANUAL_EN		BIT(3)
> +
> +#define OV5648_AWB_DELTA_REG			0x5181
> +#define OV5648_AWB_STABLE_RANGE_REG		0x5182
> +#define OV5648_AWB_STABLE_RANGE_WIDE_REG	0x5183
> +#define OV5648_HSIZE_MAN_REG			0x5185
> +
> +#define OV5648_GAIN_RED_MAN_H_REG		0x5186
> +#define OV5648_GAIN_RED_MAN_H(v)		(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_GAIN_RED_MAN_L_REG		0x5187
> +#define OV5648_GAIN_RED_MAN_L(v)		((v) & GENMASK(7, 0))
> +#define OV5648_GAIN_GREEN_MAN_H_REG		0x5188
> +#define OV5648_GAIN_GREEN_MAN_H(v)		(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_GAIN_GREEN_MAN_L_REG		0x5189
> +#define OV5648_GAIN_GREEN_MAN_L(v)		((v) & GENMASK(7, 0))
> +#define OV5648_GAIN_BLUE_MAN_H_REG		0x518a
> +#define OV5648_GAIN_BLUE_MAN_H(v)		(((v) & GENMASK(11, 8)) >> 8)
> +#define OV5648_GAIN_BLUE_MAN_L_REG		0x518b
> +#define OV5648_GAIN_BLUE_MAN_L(v)		((v) & GENMASK(7, 0))
> +#define OV5648_GAIN_RED_LIMIT_REG		0x518c
> +#define OV5648_GAIN_GREEN_LIMIT_REG		0x518d
> +#define OV5648_GAIN_BLUE_LIMIT_REG		0x518e
> +#define OV5648_AWB_FRAME_COUNT_REG		0x518f
> +#define OV5648_AWB_BASE_MAN_REG			0x51df
> +
> +/* Macros */
> +
> +#define ov5648_subdev_sensor(subdev) \
> +	container_of(subdev, struct ov5648_sensor, subdev)
> +
> +#define ov5648_ctrl_subdev(ctrl) \
> +	(&container_of(ctrl->handler, struct ov5648_sensor, ctrls.handler)->subdev)
> +
> +/* Data structures */
> +
> +struct ov5648_register_value {
> +	u16 address;
> +	u8 value;
> +	unsigned int delay_ms;
> +};
> +
> +/*
> + * PLL1 Clock Tree:
> + *
> + * +-< XVCLK
> + * |
> + * +-+ pll_pre_div (0x3037 [3:0], special values: 5: 1.5, 7: 2.5)
> + *   |
> + *   +-+ pll_mul (0x3036 [7:0])
> + *     |
> + *     +-+ sys_div (0x3035 [7:4])
> + *       |
> + *       +-+ mipi_div (0x3035 [3:0])
> + *       | |
> + *       | +-> MIPI_SCLK
> + *       | |
> + *       | +-+ mipi_phy_div (2)
> + *       |   |
> + *       |   +-> MIPI_CLK
> + *       |
> + *       +-+ root_div (0x3037 [4])
> + *         |
> + *         +-+ bit_div (0x3034 [3:0], 8 bits: 2, 10 bits: 2.5, other: 1)
> + *           |
> + *           +-+ sclk_div (0x3106 [3:2])
> + *             |
> + *             +-> SCLK
> + *             |
> + *             +-+ mipi_div (0x3035, 1: PCLK = SCLK)
> + *               |
> + *               +-> PCLK
> + */
> +
> +struct ov5648_pll1_config {
> +	unsigned int pll_pre_div;
> +	unsigned int pll_mul;
> +	unsigned int sys_div;
> +	unsigned int root_div;
> +	unsigned int sclk_div;
> +	unsigned int mipi_div;
> +};
> +
> +/*
> + * PLL2 Clock Tree:
> + *
> + * +-< XVCLK
> + * |
> + * +-+ plls_pre_div (0x303d [5:4], special values: 0: 1, 1: 1.5)
> + *   |
> + *   +-+ plls_div_r (0x303d [2])
> + *     |
> + *     +-+ plls_mul (0x303b [4:0])
> + *       |
> + *       +-+ sys_div (0x303c [3:0])
> + *         |
> + *         +-+ sel_div (0x303d [1:0], special values: 0: 1, 3: 2.5)
> + *           |
> + *           +-> ADCLK
> + */
> +
> +struct ov5648_pll2_config {
> +	unsigned int plls_pre_div;
> +	unsigned int plls_div_r;
> +	unsigned int plls_mul;
> +	unsigned int sys_div;
> +	unsigned int sel_div;
> +};
> +
> +/*
> + * General formulas for (array-centered) mode calculation:
> + * - photo_array_width = 2624
> + * - crop_start_x = (photo_array_width - output_size_x) / 2
> + * - crop_end_x = crop_start_x + offset_x + output_size_x - 1
> + *
> + * - photo_array_height = 1956
> + * - crop_start_y = (photo_array_height - output_size_y) / 2
> + * - crop_end_y = crop_start_y + offset_y + output_size_y - 1
> + */
> +
> +struct ov5648_mode {
> +	unsigned int crop_start_x;
> +	unsigned int offset_x;
> +	unsigned int output_size_x;
> +	unsigned int crop_end_x;
> +	unsigned int hts;
> +
> +	unsigned int crop_start_y;
> +	unsigned int offset_y;
> +	unsigned int output_size_y;
> +	unsigned int crop_end_y;
> +	unsigned int vts;
> +
> +	bool binning_x;
> +	bool binning_y;
> +
> +	unsigned int inc_x_odd;
> +	unsigned int inc_x_even;
> +	unsigned int inc_y_odd;
> +	unsigned int inc_y_even;
> +
> +	/* 8-bit frame interval followed by 10-bit frame interval. */
> +	struct v4l2_fract frame_interval[2];
> +
> +	/* 8-bit config followed by 10-bit config. */
> +	const struct ov5648_pll1_config *pll1_config[2];
> +	const struct ov5648_pll2_config *pll2_config;
> +
> +	const struct ov5648_register_value *register_values;
> +	unsigned int register_values_count;
> +};
> +
> +struct ov5648_state {
> +	const struct ov5648_mode *mode;
> +	u32 mbus_code;
> +
> +	int power_count;
> +	bool streaming;
> +};
> +
> +struct ov5648_ctrls {
> +	struct v4l2_ctrl *exposure_auto;
> +	struct v4l2_ctrl *exposure;
> +
> +	struct v4l2_ctrl *gain_auto;
> +	struct v4l2_ctrl *gain;
> +
> +	struct v4l2_ctrl *white_balance_auto;
> +	struct v4l2_ctrl *red_balance;
> +	struct v4l2_ctrl *blue_balance;
> +
> +	struct v4l2_ctrl *flip_horz;
> +	struct v4l2_ctrl *flip_vert;
> +
> +	struct v4l2_ctrl *test_pattern;
> +
> +	struct v4l2_ctrl *link_freq;
> +	struct v4l2_ctrl *pixel_rate;

If you don't need these pointers, do not keep them around. At least some
are unused.

> +
> +	struct v4l2_ctrl_handler handler;
> +} __packed;

Why packed?

> +
> +struct ov5648_sensor {
> +	struct device *dev;
> +	struct i2c_client *i2c_client;
> +	struct gpio_desc *reset;
> +	struct gpio_desc *powerdown;
> +	struct regulator *avdd;
> +	struct regulator *dvdd;
> +	struct regulator *dovdd;
> +	struct clk *xvclk;
> +
> +	struct v4l2_fwnode_endpoint endpoint;
> +	struct v4l2_subdev subdev;
> +	struct media_pad pad;
> +
> +	struct mutex mutex;
> +
> +	struct ov5648_state state;
> +	struct ov5648_ctrls ctrls;
> +};
> +
> +/* Static definitions */
> +
> +/*
> + * XVCLK = 24 MHz
> + * SCLK  = 84 MHz
> + * PCLK  = 84 MHz
> + */
> +static const struct ov5648_pll1_config ov5648_pll1_config_native_8_bits = {
> +	.pll_pre_div	= 3,
> +	.pll_mul	= 84,
> +	.sys_div	= 2,
> +	.root_div	= 1,
> +	.sclk_div	= 1,
> +	.mipi_div	= 1,
> +};
> +
> +/*
> + * XVCLK = 24 MHz
> + * SCLK  = 84 MHz
> + * PCLK  = 84 MHz
> + */
> +static const struct ov5648_pll1_config ov5648_pll1_config_native_10_bits = {
> +	.pll_pre_div	= 3,
> +	.pll_mul	= 105,
> +	.sys_div	= 2,
> +	.root_div	= 1,
> +	.sclk_div	= 1,
> +	.mipi_div	= 1,
> +};
> +
> +/*
> + * XVCLK = 24 MHz
> + * ADCLK = 200 MHz
> + */
> +static const struct ov5648_pll2_config ov5648_pll2_config_native = {
> +	.plls_pre_div	= 3,
> +	.plls_div_r	= 1,
> +	.plls_mul	= 25,
> +	.sys_div	= 1,
> +	.sel_div	= 1,
> +};
> +
> +static const struct ov5648_mode ov5648_mode_qsxga = {
> +	/* Horizontal */
> +	.crop_start_x	= 16,
> +	.offset_x	= 0,
> +	.output_size_x	= 2592,
> +	.crop_end_x	= 2607,
> +	.hts		= 2816,
> +
> +	/* Vertical */
> +	.crop_start_y	= 6,
> +	.offset_y	= 0,
> +	.output_size_y	= 1944,
> +	.crop_end_y	= 1949,
> +	.vts		= 1984,
> +
> +	/* Subsample increase */
> +	.inc_x_odd	= 1,
> +	.inc_x_even	= 1,
> +	.inc_y_odd	= 1,
> +	.inc_y_even	= 1,
> +
> +	/* Frame Interval */
> +	.frame_interval	= {
> +		{ 1,	15 },
> +		{ 1,	15 },
> +	},
> +
> +	/* PLL */
> +	.pll1_config	= {
> +		&ov5648_pll1_config_native_8_bits,
> +		&ov5648_pll1_config_native_10_bits,
> +	},
> +	.pll2_config	= &ov5648_pll2_config_native,
> +};
> +
> +static const struct ov5648_mode ov5648_mode_uxga = {
> +	/* Horizontal */
> +	.crop_start_x	= 512,
> +	.offset_x	= 0,
> +	.output_size_x	= 1600,
> +	.crop_end_x	= 2111,
> +	.hts		= 2816,
> +
> +	/* Vertical */
> +	.crop_start_y	= 378,
> +	.offset_y	= 0,
> +	.output_size_y	= 1200,
> +	.crop_end_y	= 1577,
> +	.vts		= 1984,
> +
> +	/* Subsample increase */
> +	.inc_x_odd	= 1,
> +	.inc_x_even	= 1,
> +	.inc_y_odd	= 1,
> +	.inc_y_even	= 1,
> +
> +	/* Frame Interval */
> +	.frame_interval	= {
> +		{ 1,	15 },
> +		{ 1,	15 },
> +	},
> +
> +	/* PLL */
> +	.pll1_config	= {
> +		&ov5648_pll1_config_native_8_bits,
> +		&ov5648_pll1_config_native_10_bits,
> +	},
> +	.pll2_config	= &ov5648_pll2_config_native,
> +};
> +
> +static const struct ov5648_mode ov5648_mode_1080p = {
> +	/* Horizontal */
> +	.crop_start_x	= 352,
> +	.offset_x	= 0,
> +	.output_size_x	= 1920,
> +	.crop_end_x	= 2271,
> +	.hts		= 2816,
> +
> +	/* Vertical */
> +	.crop_start_y	= 438,
> +	.offset_y	= 0,
> +	.output_size_y	= 1080,
> +	.crop_end_y	= 1517,
> +	.vts		= 1984,
> +
> +	/* Subsample increase */
> +	.inc_x_odd	= 1,
> +	.inc_x_even	= 1,
> +	.inc_y_odd	= 1,
> +	.inc_y_even	= 1,
> +
> +	/* Frame Interval */
> +	.frame_interval	= {
> +		{ 1,	15 },
> +		{ 1,	15 },
> +	},
> +
> +	/* PLL */
> +	.pll1_config	= {
> +		&ov5648_pll1_config_native_8_bits,
> +		&ov5648_pll1_config_native_10_bits,
> +	},
> +	.pll2_config	= &ov5648_pll2_config_native,
> +};
> +
> +static const struct ov5648_mode ov5648_mode_1280x960 = {
> +	/* From gf ref */
> +	/* Horizontal */
> +	.crop_start_x	= 16,
> +	.offset_x	= 8,
> +	.output_size_x	= 1280,
> +	.crop_end_x	= 2607,
> +	.hts		= 1912,
> +
> +	/* Vertical */
> +	.crop_start_y	= 6,
> +	.offset_y	= 6,
> +	.output_size_y	= 960,
> +	.crop_end_y	= 1949,
> +	.vts		= 1496,
> +
> +	/* Binning */
> +	.binning_x	= true,
> +
> +	/* Subsample increase */
> +	.inc_x_odd	= 3,
> +	.inc_x_even	= 1,
> +	.inc_y_odd	= 3,
> +	.inc_y_even	= 1,
> +
> +	/* Frame Interval */
> +	.frame_interval	= {
> +		{ 1,	30 },
> +		{ 1,	30 },
> +	},
> +
> +	/* PLL */
> +	.pll1_config	= {
> +		&ov5648_pll1_config_native_8_bits,
> +		&ov5648_pll1_config_native_10_bits,
> +	},
> +	.pll2_config	= &ov5648_pll2_config_native,
> +};
> +
> +static const struct ov5648_mode ov5648_mode_720p = {
> +	/* From gf ref */
> +	/* Horizontal */
> +	.crop_start_x	= 16,
> +	.offset_x	= 8,
> +	.output_size_x	= 1280,
> +	.crop_end_x	= 2607,
> +	.hts		= 1912,
> +
> +	/* Vertical */
> +	.crop_start_y	= 254,
> +	.offset_y	= 2,
> +	.output_size_y	= 720,
> +	.crop_end_y	= 1701,
> +	.vts		= 1496,
> +
> +	/* Binning */
> +	.binning_x	= true,
> +
> +	/* Subsample increase */
> +	.inc_x_odd	= 3,
> +	.inc_x_even	= 1,
> +	.inc_y_odd	= 3,
> +	.inc_y_even	= 1,
> +
> +	/* Frame Interval */
> +	.frame_interval	= {
> +		{ 1,	30 },
> +		{ 1,	30 },
> +	},
> +
> +	/* PLL */
> +	.pll1_config	= {
> +		&ov5648_pll1_config_native_8_bits,
> +		&ov5648_pll1_config_native_10_bits,
> +	},
> +	.pll2_config	= &ov5648_pll2_config_native,
> +};
> +
> +static const struct ov5648_mode ov5648_mode_vga = {
> +	/* From gf ref */
> +	/* Horizontal */
> +	.crop_start_x	= 0,
> +	.offset_x	= 8,
> +	.output_size_x	= 640,
> +	.crop_end_x	= 2623,
> +	.hts		= 1896,
> +
> +	/* Vertical */
> +	.crop_start_y	= 0,
> +	.offset_y	= 2,
> +	.output_size_y	= 480,
> +	.crop_end_y	= 1953,
> +	.vts		= 984,
> +
> +	/* Binning */
> +	.binning_x	= true,
> +
> +	/* Subsample increase */
> +	.inc_x_odd	= 7,
> +	.inc_x_even	= 1,
> +	.inc_y_odd	= 7,
> +	.inc_y_even	= 1,
> +
> +	/* Frame Interval */
> +	.frame_interval	= {
> +		{ 1,	30 },
> +		{ 1,	30 },
> +	},
> +
> +	/* PLL */
> +	.pll1_config	= {
> +		&ov5648_pll1_config_native_8_bits,
> +		&ov5648_pll1_config_native_10_bits,
> +	},
> +	.pll2_config	= &ov5648_pll2_config_native,
> +};
> +
> +static const struct ov5648_mode *ov5648_modes[] = {
> +	&ov5648_mode_qsxga,
> +	&ov5648_mode_uxga,
> +	&ov5648_mode_1080p,
> +	&ov5648_mode_1280x960,
> +	&ov5648_mode_720p,
> +	&ov5648_mode_vga,
> +};
> +
> +static const u32 ov5648_mbus_codes[] = {
> +	MEDIA_BUS_FMT_SBGGR8_1X8,
> +	MEDIA_BUS_FMT_SBGGR10_1X10,
> +};
> +
> +static const struct ov5648_register_value ov5648_init_sequence[] = {
> +	/* PSRAM */
> +	{ OV5648_PSRAM_CTRL1_REG, 0x0d },
> +	{ OV5648_PSRAM_CTRLF_REG, 0xf5 },
> +};
> +
> +static const s64 ov5648_link_freq_menu[] = {
> +	210000000,
> +	168000000,
> +};
> +
> +static const char *const ov5648_test_pattern_menu[] = {
> +	"Disabled",
> +	"Random data",
> +	"Color bars",
> +	"Color bars with rolling bar",
> +	"Color squares",
> +	"Color squares with rolling bar"
> +};
> +
> +static const u8 ov5648_test_pattern_bits[] = {
> +	0,
> +	OV5648_ISP_CTRL3D_PATTERN_EN | OV5648_ISP_CTRL3D_PATTERN_RANDOM_DATA,
> +	OV5648_ISP_CTRL3D_PATTERN_EN | OV5648_ISP_CTRL3D_PATTERN_COLOR_BARS,
> +	OV5648_ISP_CTRL3D_PATTERN_EN | OV5648_ISP_CTRL3D_ROLLING_BAR_EN |
> +	OV5648_ISP_CTRL3D_PATTERN_COLOR_BARS,
> +	OV5648_ISP_CTRL3D_PATTERN_EN | OV5648_ISP_CTRL3D_PATTERN_COLOR_SQUARES,
> +	OV5648_ISP_CTRL3D_PATTERN_EN | OV5648_ISP_CTRL3D_ROLLING_BAR_EN |
> +	OV5648_ISP_CTRL3D_PATTERN_COLOR_SQUARES,
> +};
> +
> +/* Input/Output */
> +
> +static int ov5648_read(struct ov5648_sensor *sensor, u16 address, u8 *value)
> +{
> +	unsigned char data[2] = { address >> 8, address & 0xff };
> +	struct i2c_client *client = sensor->i2c_client;
> +	int ret;
> +
> +	ret = i2c_master_send(client, data, sizeof(data));
> +	if (ret < 0) {
> +		dev_dbg(&client->dev, "i2c send error at address %#04x\n",
> +			address);
> +		return ret;
> +	}
> +
> +	ret = i2c_master_recv(client, value, 1);
> +	if (ret < 0) {
> +		dev_dbg(&client->dev, "i2c recv error at address %#04x\n",
> +			address);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ov5648_write(struct ov5648_sensor *sensor, u16 address, u8 value)
> +{
> +	unsigned char data[3] = { address >> 8, address & 0xff, value };
> +	struct i2c_client *client = sensor->i2c_client;
> +	int ret;
> +
> +	ret = i2c_master_send(client, data, sizeof(data));
> +	if (ret < 0) {
> +		dev_dbg(&client->dev, "i2c send error at address %#04x\n",
> +			address);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ov5648_write_sequence(struct ov5648_sensor *sensor,
> +				 const struct ov5648_register_value *sequence,
> +				 unsigned int sequence_count)
> +{
> +	unsigned int i;
> +	int ret = 0;
> +
> +	for (i = 0; i < sequence_count; i++) {
> +		ret = ov5648_write(sensor, sequence[i].address,
> +				   sequence[i].value);
> +		if (ret)
> +			break;
> +
> +		if (sequence[i].delay_ms)
> +			msleep(sequence[i].delay_ms);
> +	}
> +
> +	return ret;
> +}
> +
> +static int ov5648_update_bits(struct ov5648_sensor *sensor, u16 address,
> +			      u8 mask, u8 bits)
> +{
> +	u8 value = 0;
> +	int ret;
> +
> +	ret = ov5648_read(sensor, address, &value);
> +	if (ret)
> +		return ret;
> +
> +	value &= ~mask;
> +	value |= bits;
> +
> +	ret = ov5648_write(sensor, address, value);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +/* Sensor */
> +
> +static int ov5648_sw_reset(struct ov5648_sensor *sensor)
> +{
> +	int ret;
> +
> +	ret = ov5648_write(sensor, OV5648_SW_RESET_REG, OV5648_SW_RESET_RESET);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_sw_standby(struct ov5648_sensor *sensor, int standby)
> +{
> +	u8 value = 0;
> +	int ret;
> +
> +	if (!standby)
> +		value = OV5648_SW_STANDBY_STREAM_ON;
> +
> +	ret = ov5648_write(sensor, OV5648_SW_STANDBY_REG, value);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_chip_id_check(struct ov5648_sensor *sensor)
> +{
> +	u16 regs[] = { OV5648_CHIP_ID_H_REG, OV5648_CHIP_ID_L_REG };
> +	u8 values[] = { OV5648_CHIP_ID_H_VALUE, OV5648_CHIP_ID_L_VALUE };
> +	unsigned int i;
> +	u8 value;
> +	int ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(regs); i++) {
> +		ret = ov5648_read(sensor, regs[i], &value);
> +		if (ret < 0)
> +			return ret;
> +
> +		if (value != values[i]) {
> +			dev_err(sensor->dev,
> +				"chip id value mismatch: %#x instead of %#x\n",
> +				value, values[i]);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int ov5648_avdd_internal_power(struct ov5648_sensor *sensor, int on)
> +{
> +	int ret;
> +
> +	ret = ov5648_write(sensor, OV5648_A_PWC_PK_O0_REG,
> +			   on ? 0 : OV5648_A_PWC_PK_O0_BP_REGULATOR_N);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_pad_configure(struct ov5648_sensor *sensor)
> +{
> +	int ret;
> +
> +	/* Configure pads as input. */
> +
> +	ret = ov5648_write(sensor, OV5648_PAD_OEN1_REG, 0);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_PAD_OEN2_REG, 0);
> +	if (ret)
> +		return ret;
> +
> +	/* Disable FREX pin. */
> +
> +	ret = ov5648_write(sensor, OV5648_PAD_PK_REG,
> +			   OV5648_PAD_PK_DRIVE_STRENGTH_1X |
> +			   OV5648_PAD_PK_FREX_N);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_mipi_configure(struct ov5648_sensor *sensor)
> +{
> +	struct v4l2_fwnode_bus_mipi_csi2 *bus_mipi_csi2 =
> +		&sensor->endpoint.bus.mipi_csi2;
> +	unsigned int lanes_count = bus_mipi_csi2->num_data_lanes;
> +	int ret;
> +
> +	ret = ov5648_write(sensor, OV5648_MIPI_CTRL0_REG,
> +			   OV5648_MIPI_CTRL0_CLK_LANE_AUTOGATE |
> +			   OV5648_MIPI_CTRL0_LANE_SELECT_LANE1 |
> +			   OV5648_MIPI_CTRL0_IDLE_LP11);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_MIPI_SC_CTRL0_REG,
> +			   OV5648_MIPI_SC_CTRL0_MIPI_LANES(lanes_count) |
> +			   OV5648_MIPI_SC_CTRL0_PHY_LP_RX_PD |
> +			   OV5648_MIPI_SC_CTRL0_MIPI_EN);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_black_level_configure(struct ov5648_sensor *sensor)
> +{
> +	int ret;
> +
> +	/* Up to 6 lines are available for black level calibration. */
> +
> +	ret = ov5648_write(sensor, OV5648_BLC_CTRL1_REG,
> +			   OV5648_BLC_CTRL1_START_LINE(2));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_BLC_CTRL2_REG,
> +			   OV5648_BLC_CTRL2_AUTO_EN |
> +			   OV5648_BLC_CTRL2_RESET_FRAME_NUM(5));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_BLC_LINE_NUM_REG,
> +			   OV5648_BLC_LINE_NUM(4));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_update_bits(sensor, OV5648_BLC_CTRL5_REG,
> +				 OV5648_BLC_CTRL5_UPDATE_EN,
> +				 OV5648_BLC_CTRL5_UPDATE_EN);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_isp_configure(struct ov5648_sensor *sensor)
> +{
> +	u8 bits;
> +	int ret;
> +
> +	/* Enable black and white level correction. */
> +	bits = OV5648_ISP_CTRL0_BLACK_CORRECT_EN |
> +	       OV5648_ISP_CTRL0_WHITE_CORRECT_EN;
> +
> +	ret = ov5648_update_bits(sensor, OV5648_ISP_CTRL0_REG, bits, bits);
> +	if (ret)
> +		return ret;
> +
> +	/* Enable AWB. */
> +	ret = ov5648_write(sensor, OV5648_ISP_CTRL1_REG,
> +			   OV5648_ISP_CTRL1_AWB_EN);
> +	if (ret)
> +		return ret;
> +
> +	/* Enable AWB gain and windowing. */
> +	ret = ov5648_write(sensor, OV5648_ISP_CTRL2_REG,
> +			   OV5648_ISP_CTRL2_WIN_EN |
> +			   OV5648_ISP_CTRL2_AWB_GAIN_EN);
> +	if (ret)
> +		return ret;
> +
> +	/* Enable buffering and auto-binning. */
> +	ret = ov5648_write(sensor, OV5648_ISP_CTRL3_REG,
> +			   OV5648_ISP_CTRL3_BUF_EN |
> +			   OV5648_ISP_CTRL3_BIN_AUTO_EN);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_ISP_CTRL4_REG, 0);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_ISP_CTRL1F_REG,
> +			   OV5648_ISP_CTRL1F_OUTPUT_EN);
> +	if (ret)
> +		return ret;
> +
> +	/* Enable post-binning filters. */
> +	ret = ov5648_write(sensor, OV5648_ISP_CTRL4B_REG,
> +			   OV5648_ISP_CTRL4B_POST_BIN_H_EN |
> +			   OV5648_ISP_CTRL4B_POST_BIN_V_EN);
> +	if (ret)
> +		return ret;
> +
> +	/* Disable debanding and night mode. Debug bit seems necessary. */
> +	ret = ov5648_write(sensor, OV5648_AEC_CTRL0_REG,
> +			   OV5648_AEC_CTRL0_DEBUG |
> +			   OV5648_AEC_CTRL0_START_SEL_EN);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_MANUAL_CTRL_REG,
> +			   OV5648_MANUAL_CTRL_FRAME_DELAY(1));
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static unsigned long ov5648_mode_pll1_rate(struct ov5648_sensor *sensor,
> +					   const struct ov5648_pll1_config *config)
> +{
> +	unsigned long xvclk_rate;
> +	unsigned long pll1_rate;
> +
> +	xvclk_rate = clk_get_rate(sensor->xvclk);
> +	pll1_rate = xvclk_rate * config->pll_mul;
> +
> +	switch (config->pll_pre_div) {
> +	case 5:
> +		pll1_rate *= 3;
> +		pll1_rate /= 2;
> +		break;
> +	case 7:
> +		pll1_rate *= 5;
> +		pll1_rate /= 2;
> +		break;
> +	default:
> +		pll1_rate /= config->pll_pre_div;
> +		break;
> +	}
> +
> +	return pll1_rate;
> +}
> +
> +static int ov5648_mode_pll1_configure(struct ov5648_sensor *sensor,
> +				      const struct ov5648_mode *mode,
> +				      u32 mbus_code)
> +{
> +	const struct ov5648_pll1_config *config;
> +	u8 value;
> +	int ret;
> +
> +	value = OV5648_PLL_CTRL0_PLL_CHARGE_PUMP(1);
> +
> +	switch (mbus_code) {
> +	case MEDIA_BUS_FMT_SBGGR8_1X8:
> +		config = mode->pll1_config[0];
> +		value |= OV5648_PLL_CTRL0_BITS(8);
> +		break;
> +	case MEDIA_BUS_FMT_SBGGR10_1X10:
> +		config = mode->pll1_config[1];
> +		value |= OV5648_PLL_CTRL0_BITS(10);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	ret = ov5648_write(sensor, OV5648_PLL_CTRL0_REG, value);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_PLL_DIV_REG,
> +			   OV5648_PLL_DIV_ROOT_DIV(config->root_div) |
> +			   OV5648_PLL_DIV_PLL_PRE_DIV(config->pll_pre_div));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_PLL_MUL_REG,
> +			   OV5648_PLL_MUL(config->pll_mul));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_PLL_CTRL1_REG,
> +			   OV5648_PLL_CTRL1_SYS_DIV(config->sys_div) |
> +			   OV5648_PLL_CTRL1_MIPI_DIV(config->mipi_div));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_SRB_CTRL_REG,
> +			   OV5648_SRB_CTRL_SCLK_DIV(config->sclk_div) |
> +			   OV5648_SRB_CTRL_SCLK_ARBITER_EN);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_mode_pll2_configure(struct ov5648_sensor *sensor,
> +				      const struct ov5648_mode *mode)
> +{
> +	const struct ov5648_pll2_config *config = mode->pll2_config;
> +	int ret;
> +
> +	ret = ov5648_write(sensor, OV5648_PLLS_DIV_REG,
> +			   OV5648_PLLS_DIV_PLLS_PRE_DIV(config->plls_pre_div) |
> +			   OV5648_PLLS_DIV_PLLS_DIV_R(config->plls_div_r) |
> +			   OV5648_PLLS_DIV_PLLS_SEL_DIV(config->sel_div));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_PLLS_MUL_REG,
> +			   OV5648_PLLS_MUL(config->plls_mul));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_PLLS_CTRL_REG,
> +			   OV5648_PLLS_CTRL_PLL_CHARGE_PUMP(1) |
> +			   OV5648_PLLS_CTRL_SYS_DIV(config->sys_div));
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_mode_configure(struct ov5648_sensor *sensor,
> +				 const struct ov5648_mode *mode, u32 mbus_code)
> +{
> +	int ret;
> +
> +	/* Crop Start X */
> +
> +	ret = ov5648_write(sensor, OV5648_CROP_START_X_H_REG,
> +			   OV5648_CROP_START_X_H(mode->crop_start_x));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_CROP_START_X_L_REG,
> +			   OV5648_CROP_START_X_L(mode->crop_start_x));
> +	if (ret)
> +		return ret;
> +
> +	/* Offset X */
> +
> +	ret = ov5648_write(sensor, OV5648_OFFSET_X_H_REG,
> +			   OV5648_OFFSET_X_H(mode->offset_x));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_OFFSET_X_L_REG,
> +			   OV5648_OFFSET_X_L(mode->offset_x));
> +	if (ret)
> +		return ret;
> +
> +	/* Output Size X */
> +
> +	ret = ov5648_write(sensor, OV5648_OUTPUT_SIZE_X_H_REG,
> +			   OV5648_OUTPUT_SIZE_X_H(mode->output_size_x));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_OUTPUT_SIZE_X_L_REG,
> +			   OV5648_OUTPUT_SIZE_X_L(mode->output_size_x));
> +	if (ret)
> +		return ret;
> +
> +	/* Crop End X */
> +
> +	ret = ov5648_write(sensor, OV5648_CROP_END_X_H_REG,
> +			   OV5648_CROP_END_X_H(mode->crop_end_x));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_CROP_END_X_L_REG,
> +			   OV5648_CROP_END_X_L(mode->crop_end_x));
> +	if (ret)
> +		return ret;
> +
> +	/* Horizontal Total Size */
> +
> +	ret = ov5648_write(sensor, OV5648_HTS_H_REG, OV5648_HTS_H(mode->hts));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_HTS_L_REG, OV5648_HTS_L(mode->hts));
> +	if (ret)
> +		return ret;
> +
> +	/* Crop Start Y */
> +
> +	ret = ov5648_write(sensor, OV5648_CROP_START_Y_H_REG,
> +			   OV5648_CROP_START_Y_H(mode->crop_start_y));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_CROP_START_Y_L_REG,
> +			   OV5648_CROP_START_Y_L(mode->crop_start_y));
> +	if (ret)
> +		return ret;
> +
> +	/* Offset Y */
> +
> +	ret = ov5648_write(sensor, OV5648_OFFSET_Y_H_REG,
> +			   OV5648_OFFSET_Y_H(mode->offset_y));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_OFFSET_Y_L_REG,
> +			   OV5648_OFFSET_Y_L(mode->offset_y));
> +	if (ret)
> +		return ret;
> +
> +	/* Output Size Y */
> +
> +	ret = ov5648_write(sensor, OV5648_OUTPUT_SIZE_Y_H_REG,
> +			   OV5648_OUTPUT_SIZE_Y_H(mode->output_size_y));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_OUTPUT_SIZE_Y_L_REG,
> +			   OV5648_OUTPUT_SIZE_Y_L(mode->output_size_y));
> +	if (ret)
> +		return ret;
> +
> +	/* Crop End Y */
> +
> +	ret = ov5648_write(sensor, OV5648_CROP_END_Y_H_REG,
> +			   OV5648_CROP_END_Y_H(mode->crop_end_y));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_CROP_END_Y_L_REG,
> +			   OV5648_CROP_END_Y_L(mode->crop_end_y));
> +	if (ret)
> +		return ret;
> +
> +	/* Vertical Total Size */
> +
> +	ret = ov5648_write(sensor, OV5648_VTS_H_REG, OV5648_VTS_H(mode->vts));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_VTS_L_REG, OV5648_VTS_L(mode->vts));
> +	if (ret)
> +		return ret;
> +
> +	/* Flip/Mirror/Binning */
> +
> +	/*
> +	 * A debug bit is enabled by default and needs to be cleared for
> +	 * subsampling to work.
> +	 */
> +	ret = ov5648_update_bits(sensor, OV5648_TC20_REG,
> +				 OV5648_TC20_DEBUG |
> +				 OV5648_TC20_BINNING_VERT_EN,
> +				 mode->binning_y ? OV5648_TC20_BINNING_VERT_EN :
> +				 0);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_update_bits(sensor, OV5648_TC21_REG,
> +				 OV5648_TC21_BINNING_HORZ_EN,
> +				 mode->binning_x ? OV5648_TC21_BINNING_HORZ_EN :
> +				 0);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_SUB_INC_X_REG,
> +			   OV5648_SUB_INC_X_ODD(mode->inc_x_odd) |
> +			   OV5648_SUB_INC_X_EVEN(mode->inc_x_even));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_SUB_INC_Y_REG,
> +			   OV5648_SUB_INC_Y_ODD(mode->inc_y_odd) |
> +			   OV5648_SUB_INC_Y_EVEN(mode->inc_y_even));
> +	if (ret)
> +		return ret;
> +
> +	/* PLLs */
> +
> +	ret = ov5648_mode_pll1_configure(sensor, mode, mbus_code);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_mode_pll2_configure(sensor, mode);
> +	if (ret)
> +		return ret;
> +
> +	/* Extra registers */
> +
> +	if (mode->register_values) {
> +		ret = ov5648_write_sequence(sensor, mode->register_values,
> +					    mode->register_values_count);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static unsigned long ov5648_mode_mipi_clk_rate(struct ov5648_sensor *sensor,
> +					       const struct ov5648_mode *mode,
> +					       u32 mbus_code)
> +{
> +	const struct ov5648_pll1_config *config;
> +	unsigned long pll1_rate;
> +	unsigned long mipi_clk_rate;
> +
> +	switch (mbus_code) {
> +	case MEDIA_BUS_FMT_SBGGR8_1X8:
> +		config = mode->pll1_config[0];
> +		break;
> +	case MEDIA_BUS_FMT_SBGGR10_1X10:
> +		config = mode->pll1_config[1];
> +		break;
> +	default:
> +		return 0;
> +	}
> +
> +	pll1_rate = ov5648_mode_pll1_rate(sensor, config);
> +	mipi_clk_rate = pll1_rate / config->sys_div / config->mipi_div / 2;

You could return the result and omit mipi_clk_rate variable.

> +
> +	return mipi_clk_rate;
> +}
> +
> +/* Exposure */
> +
> +static int ov5648_exposure_auto_configure(struct ov5648_sensor *sensor,
> +					  bool enable)
> +{
> +	int ret;
> +
> +	ret = ov5648_update_bits(sensor, OV5648_MANUAL_CTRL_REG,

Could you change this to return a value you don't need to further process?

And then make the changes to other similar instances, too.

> +				 OV5648_MANUAL_CTRL_AEC_MANUAL_EN,
> +				 enable ? 0 : OV5648_MANUAL_CTRL_AEC_MANUAL_EN);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_exposure_configure(struct ov5648_sensor *sensor, u32 exposure)
> +{
> +	struct ov5648_ctrls *ctrls = &sensor->ctrls;
> +	int ret;
> +
> +	if (ctrls->exposure_auto->val != V4L2_EXPOSURE_MANUAL)
> +		return -EINVAL;
> +
> +	ret = ov5648_write(sensor, OV5648_EXPOSURE_CTRL_HH_REG,
> +			   OV5648_EXPOSURE_CTRL_HH(exposure));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_EXPOSURE_CTRL_H_REG,
> +			   OV5648_EXPOSURE_CTRL_H(exposure));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_EXPOSURE_CTRL_L_REG,
> +			   OV5648_EXPOSURE_CTRL_L(exposure));
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_exposure_value(struct ov5648_sensor *sensor,
> +				 u32 *exposure)
> +{
> +	u8 exposure_hh = 0, exposure_h = 0, exposure_l = 0;
> +	int ret;
> +
> +	ret = ov5648_read(sensor, OV5648_EXPOSURE_CTRL_HH_REG, &exposure_hh);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_read(sensor, OV5648_EXPOSURE_CTRL_H_REG, &exposure_h);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_read(sensor, OV5648_EXPOSURE_CTRL_L_REG, &exposure_l);
> +	if (ret)
> +		return ret;
> +
> +	*exposure = OV5648_EXPOSURE_CTRL_HH_VALUE((u32)exposure_hh) |
> +		    OV5648_EXPOSURE_CTRL_H_VALUE((u32)exposure_h) |
> +		    OV5648_EXPOSURE_CTRL_L_VALUE((u32)exposure_l);
> +
> +	return 0;
> +}
> +
> +/* Gain */
> +
> +static int ov5648_gain_auto_configure(struct ov5648_sensor *sensor, bool enable)
> +{
> +	int ret;
> +
> +	ret = ov5648_update_bits(sensor, OV5648_MANUAL_CTRL_REG,
> +				 OV5648_MANUAL_CTRL_AGC_MANUAL_EN,
> +				 enable ? 0 : OV5648_MANUAL_CTRL_AGC_MANUAL_EN);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_gain_configure(struct ov5648_sensor *sensor, u32 gain)
> +{
> +	struct ov5648_ctrls *ctrls = &sensor->ctrls;
> +	int ret;
> +
> +	if (ctrls->gain_auto->val)
> +		return -EINVAL;
> +
> +	ret = ov5648_write(sensor, OV5648_GAIN_CTRL_H_REG,
> +			   OV5648_GAIN_CTRL_H(gain));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_GAIN_CTRL_L_REG,
> +			   OV5648_GAIN_CTRL_L(gain));
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_gain_value(struct ov5648_sensor *sensor, u32 *gain)
> +{
> +	u8 gain_h = 0, gain_l = 0;
> +	int ret;
> +
> +	ret = ov5648_read(sensor, OV5648_GAIN_CTRL_H_REG, &gain_h);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_read(sensor, OV5648_GAIN_CTRL_L_REG, &gain_l);
> +	if (ret)
> +		return ret;
> +
> +	*gain = OV5648_GAIN_CTRL_H_VALUE((u32)gain_h) |
> +		OV5648_GAIN_CTRL_L_VALUE((u32)gain_l);
> +
> +	return 0;
> +}
> +
> +/* White Balance */
> +
> +static int ov5648_white_balance_auto_configure(struct ov5648_sensor *sensor,
> +					       bool enable)
> +{
> +	int ret;
> +
> +	ret = ov5648_write(sensor, OV5648_AWB_CTRL_REG,
> +			   enable ? 0 : OV5648_AWB_CTRL_GAIN_MANUAL_EN);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_white_balance_configure(struct ov5648_sensor *sensor,
> +					  u32 red_balance, u32 blue_balance)
> +{
> +	struct ov5648_ctrls *ctrls = &sensor->ctrls;
> +	int ret;
> +
> +	if (ctrls->white_balance_auto->val)
> +		return -EINVAL;
> +
> +	ret = ov5648_write(sensor, OV5648_GAIN_RED_MAN_H_REG,
> +			   OV5648_GAIN_RED_MAN_H(red_balance));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_GAIN_RED_MAN_L_REG,
> +			   OV5648_GAIN_RED_MAN_L(red_balance));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_GAIN_BLUE_MAN_H_REG,
> +			   OV5648_GAIN_BLUE_MAN_H(blue_balance));
> +	if (ret)
> +		return ret;
> +
> +	ret = ov5648_write(sensor, OV5648_GAIN_BLUE_MAN_L_REG,
> +			   OV5648_GAIN_BLUE_MAN_L(blue_balance));
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +/* Flip */
> +
> +static int ov5648_flip_vert_configure(struct ov5648_sensor *sensor, bool enable)
> +{
> +	u8 bits = OV5648_TC20_FLIP_VERT_ISP_EN |
> +		  OV5648_TC20_FLIP_VERT_SENSOR_EN;
> +	int ret;
> +
> +	ret = ov5648_update_bits(sensor, OV5648_TC20_REG, bits,
> +				 enable ? bits : 0);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5648_flip_horz_configure(struct ov5648_sensor *sensor, bool enable)
> +{
> +	u8 bits = OV5648_TC21_FLIP_HORZ_ISP_EN |
> +		  OV5648_TC21_FLIP_HORZ_SENSOR_EN;
> +	int ret;
> +
> +	ret = ov5648_update_bits(sensor, OV5648_TC21_REG, bits,
> +				 enable ? bits : 0);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +/* Test Pattern */
> +
> +static int ov5648_test_pattern_configure(struct ov5648_sensor *sensor, u8 bits)
> +{
> +	int ret;
> +
> +	ret = ov5648_write(sensor, OV5648_ISP_CTRL3D_REG, bits);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +/* State */
> +
> +static int ov5648_state_mipi_configure(struct ov5648_sensor *sensor,
> +				       const struct ov5648_mode *mode,
> +				       u32 mbus_code)
> +{
> +	struct ov5648_ctrls *ctrls = &sensor->ctrls;
> +	struct v4l2_fwnode_bus_mipi_csi2 *bus_mipi_csi2 =
> +		&sensor->endpoint.bus.mipi_csi2;
> +	unsigned long mipi_clk_rate;
> +	unsigned int bits_per_sample;
> +	unsigned int lanes_count;
> +	unsigned int i;
> +	s64 mipi_pixel_rate;
> +
> +	mipi_clk_rate = ov5648_mode_mipi_clk_rate(sensor, mode, mbus_code);
> +	if (!mipi_clk_rate)
> +		return -EINVAL;
> +
> +	for (i = 0; i < ARRAY_SIZE(ov5648_link_freq_menu); i++) {
> +		s64 freq = ov5648_link_freq_menu[i];
> +
> +		if (freq == mipi_clk_rate)
> +			break;
> +	}
> +
> +	if (i == ARRAY_SIZE(ov5648_link_freq_menu)) {
> +		dev_err(sensor->dev,
> +			"failed to find %lu clk rate in link freq\n",
> +			mipi_clk_rate);
> +	} else {
> +		__v4l2_ctrl_s_ctrl(ctrls->link_freq, i);
> +	}
> +
> +	switch (mbus_code) {
> +	case MEDIA_BUS_FMT_SBGGR8_1X8:
> +		bits_per_sample = 8;
> +		break;
> +	case MEDIA_BUS_FMT_SBGGR10_1X10:
> +		bits_per_sample = 10;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	lanes_count = bus_mipi_csi2->num_data_lanes;
> +	mipi_pixel_rate = mipi_clk_rate * 2 * lanes_count / bits_per_sample;
> +
> +	__v4l2_ctrl_s_ctrl_int64(ctrls->pixel_rate, mipi_pixel_rate);
> +
> +	return 0;
> +}
> +
> +static int ov5648_state_configure(struct ov5648_sensor *sensor,
> +				  const struct ov5648_mode *mode,
> +				  u32 mbus_code)
> +{
> +	int ret;
> +
> +	if (sensor->state.streaming)
> +		return -EBUSY;
> +
> +	/* State will be configured at first power on otherwise. */
> +	if (sensor->state.power_count > 0) {
> +		ret = ov5648_mode_configure(sensor, mode, mbus_code);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = ov5648_state_mipi_configure(sensor, mode, mbus_code);
> +	if (ret)
> +		return ret;
> +
> +	sensor->state.mode = mode;
> +	sensor->state.mbus_code = mbus_code;
> +
> +	return 0;
> +}
> +
> +static int ov5648_state_init(struct ov5648_sensor *sensor)
> +{
> +	return ov5648_state_configure(sensor, ov5648_modes[0],
> +				      ov5648_mbus_codes[0]);
> +}
> +
> +/* Sensor Base */
> +
> +static int ov5648_sensor_init(struct ov5648_sensor *sensor)
> +{
> +	int ret;
> +
> +	ret = ov5648_sw_reset(sensor);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to perform sw reset\n");
> +		return ret;
> +	}
> +
> +	ret = ov5648_sw_standby(sensor, 1);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to set sensor standby\n");
> +		return ret;
> +	}
> +
> +	ret = ov5648_chip_id_check(sensor);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to check sensor chip id\n");
> +		return ret;
> +	}
> +
> +	ret = ov5648_avdd_internal_power(sensor, !sensor->avdd);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to set internal avdd power\n");
> +		return ret;
> +	}
> +
> +	ret = ov5648_write_sequence(sensor, ov5648_init_sequence,
> +				    ARRAY_SIZE(ov5648_init_sequence));
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to write init sequence\n");
> +		return ret;
> +	}
> +
> +	ret = ov5648_pad_configure(sensor);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to configure pad\n");
> +		return ret;
> +	}
> +
> +	ret = ov5648_mipi_configure(sensor);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to configure MIPI\n");
> +		return ret;
> +	}
> +
> +	ret = ov5648_isp_configure(sensor);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to configure ISP\n");
> +		return ret;
> +	}
> +
> +	ret = ov5648_black_level_configure(sensor);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to configure black level\n");
> +		return ret;
> +	}
> +
> +	/* Configure current mode. */
> +	ret = ov5648_state_configure(sensor, sensor->state.mode,
> +				     sensor->state.mbus_code);
> +	if (ret) {
> +		dev_err(sensor->dev, "failed to configure state\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ov5648_sensor_power(struct ov5648_sensor *sensor, bool on)
> +{
> +	/* Keep initialized to zero for disable label. */
> +	int ret = 0;
> +
> +	/*
> +	 * General notes about the power sequence:
> +	 * - power-down GPIO must be active (low) during power-on;
> +	 * - reset GPIO state does not matter during power-on;
> +	 * - XVCLK must be provided 1 ms before register access;
> +	 * - 10 ms are needed between power-down deassert and register access.
> +	 */
> +
> +	/* Note that regulator-and-GPIO-based power is untested. */
> +	if (on) {
> +		gpiod_set_value_cansleep(sensor->reset, 1);
> +		gpiod_set_value_cansleep(sensor->powerdown, 1);
> +
> +		ret = regulator_enable(sensor->dovdd);
> +		if (ret) {
> +			dev_err(sensor->dev,
> +				"failed to enable DOVDD regulator\n");
> +			goto disable;
> +		}
> +
> +		if (sensor->avdd) {
> +			ret = regulator_enable(sensor->avdd);
> +			if (ret) {
> +				dev_err(sensor->dev,
> +					"failed to enable AVDD regulator\n");
> +				goto disable;
> +			}
> +		}
> +
> +		ret = regulator_enable(sensor->dvdd);
> +		if (ret) {
> +			dev_err(sensor->dev,
> +				"failed to enable DVDD regulator\n");
> +			goto disable;
> +		}
> +
> +		/* According to OV5648 power up diagram. */
> +		usleep_range(5000, 10000);
> +
> +		ret = clk_prepare_enable(sensor->xvclk);
> +		if (ret) {
> +			dev_err(sensor->dev, "failed to enable XVCLK clock\n");
> +			goto disable;
> +		}
> +
> +		gpiod_set_value_cansleep(sensor->reset, 0);
> +		gpiod_set_value_cansleep(sensor->powerdown, 0);
> +
> +		usleep_range(20000, 25000);
> +	} else {
> +disable:
> +		gpiod_set_value_cansleep(sensor->powerdown, 1);
> +		gpiod_set_value_cansleep(sensor->reset, 1);
> +
> +		clk_disable_unprepare(sensor->xvclk);
> +
> +		regulator_disable(sensor->dvdd);
> +
> +		if (sensor->avdd)
> +			regulator_disable(sensor->avdd);
> +
> +		regulator_disable(sensor->dovdd);
> +	}
> +
> +	return ret;
> +}
> +
> +/* Controls */
> +
> +static int ov5648_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct v4l2_subdev *subdev = ov5648_ctrl_subdev(ctrl);
> +	struct ov5648_sensor *sensor = ov5648_subdev_sensor(subdev);
> +	struct ov5648_ctrls *ctrls = &sensor->ctrls;
> +	int ret;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_EXPOSURE_AUTO:
> +		ret = ov5648_exposure_value(sensor, &ctrls->exposure->val);
> +		if (ret)
> +			return ret;
> +		break;
> +	case V4L2_CID_AUTOGAIN:
> +		ret = ov5648_gain_value(sensor, &ctrls->gain->val);
> +		if (ret)
> +			return ret;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ov5648_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct v4l2_subdev *subdev = ov5648_ctrl_subdev(ctrl);
> +	struct ov5648_sensor *sensor = ov5648_subdev_sensor(subdev);
> +	struct ov5648_state *state = &sensor->state;
> +	struct ov5648_ctrls *ctrls = &sensor->ctrls;
> +	bool enable;
> +	u8 bits;
> +	int ret;
> +
> +	/* Wait for the sensor to be on before setting controls. */
> +	if (state->power_count == 0)
> +		return 0;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_EXPOSURE_AUTO:
> +		enable = ctrl->val == V4L2_EXPOSURE_AUTO;
> +
> +		ret = ov5648_exposure_auto_configure(sensor, enable);
> +		if (ret)
> +			return ret;
> +
> +		if (!enable && ctrls->exposure->is_new) {
> +			ret = ov5648_exposure_configure(sensor,
> +							ctrls->exposure->val);
> +			if (ret)
> +				return ret;
> +		}
> +		break;
> +	case V4L2_CID_AUTOGAIN:
> +		enable = !!ctrl->val;
> +
> +		ret = ov5648_gain_auto_configure(sensor, enable);
> +		if (ret)
> +			return ret;
> +
> +		if (!enable) {
> +			ret = ov5648_gain_configure(sensor, ctrls->gain->val);
> +			if (ret)
> +				return ret;
> +		}
> +		break;
> +	case V4L2_CID_AUTO_WHITE_BALANCE:
> +		enable = !!ctrl->val;
> +
> +		ret = ov5648_white_balance_auto_configure(sensor, enable);
> +		if (ret)
> +			return ret;
> +
> +		if (!enable) {
> +			ret = ov5648_white_balance_configure(sensor,
> +							     ctrls->red_balance->val,
> +							     ctrls->blue_balance->val);
> +			if (ret)
> +				return ret;
> +		}
> +		break;
> +	case V4L2_CID_HFLIP:
> +		enable = !!ctrl->val;
> +		return ov5648_flip_horz_configure(sensor, enable);
> +	case V4L2_CID_VFLIP:
> +		enable = !!ctrl->val;
> +		return ov5648_flip_vert_configure(sensor, enable);
> +	case V4L2_CID_TEST_PATTERN:
> +		bits = ov5648_test_pattern_bits[ctrl->val];
> +		return ov5648_test_pattern_configure(sensor, bits);
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_ctrl_ops ov5648_ctrl_ops = {
> +	.g_volatile_ctrl	= ov5648_g_volatile_ctrl,
> +	.s_ctrl			= ov5648_s_ctrl,
> +};
> +
> +static int ov5648_ctrls_init(struct ov5648_sensor *sensor)
> +{
> +	struct ov5648_ctrls *ctrls = &sensor->ctrls;
> +	struct v4l2_ctrl_handler *handler = &ctrls->handler;
> +	const struct v4l2_ctrl_ops *ops = &ov5648_ctrl_ops;
> +	int ret;
> +
> +	v4l2_ctrl_handler_init(handler, 32);
> +
> +	/* Use our mutex for ctrl locking. */
> +	handler->lock = &sensor->mutex;
> +
> +	/* Exposure */
> +
> +	ctrls->exposure_auto = v4l2_ctrl_new_std_menu(handler, ops,
> +						      V4L2_CID_EXPOSURE_AUTO,
> +						      V4L2_EXPOSURE_MANUAL, 0,
> +						      V4L2_EXPOSURE_AUTO);
> +
> +	ctrls->exposure = v4l2_ctrl_new_std(handler, ops, V4L2_CID_EXPOSURE,
> +					    16, 1048575, 16, 512);
> +	ctrls->exposure->flags |= V4L2_CTRL_FLAG_VOLATILE;
> +
> +	v4l2_ctrl_auto_cluster(2, &ctrls->exposure_auto, 1, true);
> +
> +	/* Gain */
> +
> +	ctrls->gain_auto = v4l2_ctrl_new_std(handler, ops, V4L2_CID_AUTOGAIN,
> +					     0, 1, 1, 1);
> +
> +	ctrls->gain = v4l2_ctrl_new_std(handler, ops, V4L2_CID_GAIN, 16, 1023,
> +					16, 16);
> +	ctrls->gain->flags |= V4L2_CTRL_FLAG_VOLATILE;
> +
> +	v4l2_ctrl_auto_cluster(2, &ctrls->gain_auto, 0, true);
> +
> +	/* White Balance */
> +
> +	ctrls->white_balance_auto = v4l2_ctrl_new_std(handler, ops,
> +						      V4L2_CID_AUTO_WHITE_BALANCE,
> +						      0, 1, 1, 1);
> +
> +	ctrls->red_balance = v4l2_ctrl_new_std(handler, ops,
> +					       V4L2_CID_RED_BALANCE, 0, 4095,
> +					       1, 1024);
> +
> +	ctrls->blue_balance = v4l2_ctrl_new_std(handler, ops,
> +						V4L2_CID_BLUE_BALANCE, 0, 4095,
> +						1, 1024);
> +
> +	v4l2_ctrl_auto_cluster(3, &ctrls->white_balance_auto, 0, false);
> +
> +	/* Flip */
> +
> +	ctrls->flip_horz = v4l2_ctrl_new_std(handler, ops, V4L2_CID_HFLIP, 0, 1,
> +					     1, 0);
> +	ctrls->flip_vert = v4l2_ctrl_new_std(handler, ops, V4L2_CID_VFLIP, 0, 1,
> +					     1, 0);
> +
> +	/* Test Pattern */
> +
> +	ctrls->test_pattern =
> +		v4l2_ctrl_new_std_menu_items(handler, ops,
> +					     V4L2_CID_TEST_PATTERN,
> +					     ARRAY_SIZE(ov5648_test_pattern_menu) - 1,
> +					     0, 0, ov5648_test_pattern_menu);
> +
> +	/* MIPI CSI-2 */
> +
> +	ctrls->link_freq =
> +		v4l2_ctrl_new_int_menu(handler, ops, V4L2_CID_LINK_FREQ,
> +				       ARRAY_SIZE(ov5648_link_freq_menu) - 1,
> +				       0, ov5648_link_freq_menu);
> +
> +	ctrls->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> +	ctrls->pixel_rate = v4l2_ctrl_new_std(handler, ops, V4L2_CID_PIXEL_RATE,
> +					      1, INT_MAX, 1, 1);
> +
> +	ctrls->pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> +	if (handler->error) {
> +		ret = handler->error;
> +		goto error_ctrls;
> +	}
> +
> +	sensor->subdev.ctrl_handler = handler;
> +
> +	return 0;
> +
> +error_ctrls:
> +	v4l2_ctrl_handler_free(handler);
> +
> +	return ret;
> +}
> +
> +/* Subdev Core Operations */
> +
> +static int ov5648_s_power(struct v4l2_subdev *subdev, int on)

Please add support for runtime PM instead. See e.g. the ov8856 driver for
an example.

> +{
> +	struct ov5648_sensor *sensor = ov5648_subdev_sensor(subdev);
> +	struct ov5648_state *state = &sensor->state;
> +	bool ctrl_handler_setup = false;
> +	int ret = 0;
> +
> +	mutex_lock(&sensor->mutex);
> +
> +	state->power_count += on ? 1 : -1;
> +
> +	/* Neither first power on nor last power off. */
> +	if (state->power_count != !!on)
> +		goto complete;
> +
> +	ret = ov5648_sensor_power(sensor, on);
> +	if (ret)
> +		goto complete;
> +
> +	/* First power on: init sensor and set controls. */
> +	if (on) {
> +		ret = ov5648_sensor_init(sensor);
> +		if (ret)
> +			goto error_power;
> +
> +		ctrl_handler_setup = true;
> +	}
> +
> +	goto complete;
> +
> +error_power:
> +	ov5648_sensor_power(sensor, !on);
> +
> +complete:
> +	mutex_unlock(&sensor->mutex);
> +
> +	if (ctrl_handler_setup)
> +		ret = v4l2_ctrl_handler_setup(&sensor->ctrls.handler);
> +
> +	return ret;
> +}
> +
> +static const struct v4l2_subdev_core_ops ov5648_subdev_core_ops = {
> +	.s_power		= ov5648_s_power,
> +};
> +
> +/* Subdev Video Operations */
> +
> +static int ov5648_s_stream(struct v4l2_subdev *subdev, int enable)
> +{
> +	struct ov5648_sensor *sensor = ov5648_subdev_sensor(subdev);
> +	int ret = 0;
> +
> +	mutex_lock(&sensor->mutex);
> +
> +	ret = ov5648_sw_standby(sensor, !enable);
> +	if (ret)
> +		goto complete;
> +
> +	sensor->state.streaming = !!enable;
> +
> +complete:
> +	mutex_unlock(&sensor->mutex);
> +
> +	return ret;
> +}
> +
> +static int ov5648_g_frame_interval(struct v4l2_subdev *subdev,
> +				   struct v4l2_subdev_frame_interval *interval)
> +{
> +	struct ov5648_sensor *sensor = ov5648_subdev_sensor(subdev);
> +	const struct ov5648_mode *mode;
> +	int ret = 0;
> +
> +	mutex_lock(&sensor->mutex);
> +
> +	mode = sensor->state.mode;
> +
> +	switch (sensor->state.mbus_code) {
> +	case MEDIA_BUS_FMT_SBGGR8_1X8:
> +		interval->interval = mode->frame_interval[0];
> +		break;
> +	case MEDIA_BUS_FMT_SBGGR10_1X10:
> +		interval->interval = mode->frame_interval[1];
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	mutex_unlock(&sensor->mutex);
> +
> +	return ret;
> +}
> +
> +static const struct v4l2_subdev_video_ops ov5648_subdev_video_ops = {
> +	.s_stream		= ov5648_s_stream,
> +	.g_frame_interval	= ov5648_g_frame_interval,
> +	.s_frame_interval	= ov5648_g_frame_interval,
> +};
> +
> +/* Subdev Pad Operations */
> +
> +static int ov5648_enum_mbus_code(struct v4l2_subdev *subdev,
> +				 struct v4l2_subdev_pad_config *config,
> +				 struct v4l2_subdev_mbus_code_enum *code_enum)
> +{
> +	if (code_enum->index >= ARRAY_SIZE(ov5648_mbus_codes))
> +		return -EINVAL;
> +
> +	code_enum->code = ov5648_mbus_codes[code_enum->index];
> +
> +	return 0;
> +}
> +
> +static void ov5648_mbus_format_fill(struct v4l2_mbus_framefmt *mbus_format,
> +				    u32 mbus_code,
> +				    const struct ov5648_mode *mode)
> +{
> +	mbus_format->width = mode->output_size_x;
> +	mbus_format->height = mode->output_size_y;
> +	mbus_format->code = mbus_code;
> +
> +	mbus_format->field = V4L2_FIELD_NONE;
> +	mbus_format->colorspace = V4L2_COLORSPACE_RAW;
> +	mbus_format->ycbcr_enc =
> +		V4L2_MAP_YCBCR_ENC_DEFAULT(mbus_format->colorspace);
> +	mbus_format->quantization = V4L2_QUANTIZATION_FULL_RANGE;
> +	mbus_format->xfer_func =
> +		V4L2_MAP_XFER_FUNC_DEFAULT(mbus_format->colorspace);
> +}
> +
> +static int ov5648_get_fmt(struct v4l2_subdev *subdev,
> +			  struct v4l2_subdev_pad_config *cfg,
> +			  struct v4l2_subdev_format *format)
> +{
> +	struct ov5648_sensor *sensor = ov5648_subdev_sensor(subdev);
> +	struct v4l2_mbus_framefmt *mbus_format = &format->format;
> +
> +	mutex_lock(&sensor->mutex);
> +
> +	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> +		*mbus_format =
> +			*v4l2_subdev_get_try_format(subdev, cfg, format->pad);
> +	} else {
> +		ov5648_mbus_format_fill(mbus_format, sensor->state.mbus_code,
> +					sensor->state.mode);
> +	}
> +
> +	mutex_unlock(&sensor->mutex);
> +
> +	return 0;
> +}
> +
> +static int ov5648_set_fmt(struct v4l2_subdev *subdev,
> +			  struct v4l2_subdev_pad_config *cfg,
> +			  struct v4l2_subdev_format *format)
> +{
> +	struct ov5648_sensor *sensor = ov5648_subdev_sensor(subdev);
> +	struct v4l2_mbus_framefmt *mbus_format = &format->format;
> +	const struct ov5648_mode *mode = ov5648_modes[0];
> +	u32 mbus_code = ov5648_mbus_codes[0];
> +	unsigned int index;
> +	int ret = 0;
> +
> +	mutex_lock(&sensor->mutex);
> +
> +	if (sensor->state.streaming) {
> +		ret = -EBUSY;
> +		goto complete;
> +	}
> +
> +	/* Try to find requested mbus code. */
> +	for (index = 0; index < ARRAY_SIZE(ov5648_mbus_codes); index++) {
> +		if (ov5648_mbus_codes[index] == mbus_format->code) {
> +			mbus_code = mbus_format->code;
> +			break;
> +		}
> +	}
> +
> +	/* Try to find requested mode code. */
> +	for (index = 0; index < ARRAY_SIZE(ov5648_modes); index++) {
> +		if (ov5648_modes[index]->output_size_x == mbus_format->width &&
> +		    ov5648_modes[index]->output_size_y == mbus_format->height) {

Please use the closest size. You can find that using
v4l2_find_nearest_size().

> +			mode = ov5648_modes[index];
> +			break;
> +		}
> +	}
> +
> +	ov5648_mbus_format_fill(mbus_format, mbus_code, mode);
> +
> +	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> +		*v4l2_subdev_get_try_format(subdev, cfg, format->pad) =
> +			*mbus_format;
> +	} else if (sensor->state.mode != mode ||
> +		   sensor->state.mbus_code != mbus_code) {
> +		ret = ov5648_state_configure(sensor, mode, mbus_code);
> +		if (ret)
> +			goto complete;
> +	}
> +
> +complete:
> +	mutex_unlock(&sensor->mutex);
> +
> +	return ret;
> +}
> +
> +static int ov5648_enum_frame_size(struct v4l2_subdev *subdev,
> +				  struct v4l2_subdev_pad_config *config,
> +				  struct v4l2_subdev_frame_size_enum *size_enum)
> +{
> +	const struct ov5648_mode *mode;
> +
> +	if (size_enum->index >= ARRAY_SIZE(ov5648_modes))
> +		return -EINVAL;
> +
> +	mode = ov5648_modes[size_enum->index];
> +
> +	size_enum->min_width = size_enum->max_width = mode->output_size_x;
> +	size_enum->min_height = size_enum->max_height = mode->output_size_y;
> +
> +	return 0;
> +}
> +
> +static int ov5648_enum_frame_interval(struct v4l2_subdev *subdev,
> +				      struct v4l2_subdev_pad_config *config,
> +				      struct v4l2_subdev_frame_interval_enum *interval_enum)
> +{
> +	const struct ov5648_mode *mode = NULL;
> +	unsigned int mode_index;
> +	unsigned int interval_index;
> +
> +	if (interval_enum->index > 0)
> +		return -EINVAL;
> +
> +	/*
> +	 * Multiple modes with the same dimensions may have different frame
> +	 * intervals, so look up each relevant mode.
> +	 */
> +	for (mode_index = 0, interval_index = 0;
> +	     mode_index < ARRAY_SIZE(ov5648_modes); mode_index++) {
> +		mode = ov5648_modes[mode_index];
> +
> +		if (mode->output_size_x == interval_enum->width &&
> +		    mode->output_size_y == interval_enum->height) {
> +			if (interval_index == interval_enum->index)
> +				break;
> +
> +			interval_index++;
> +		}
> +	}
> +
> +	if (mode_index == ARRAY_SIZE(ov5648_modes) || !mode)
> +		return -EINVAL;
> +
> +	switch (interval_enum->code) {
> +	case MEDIA_BUS_FMT_SBGGR8_1X8:
> +		interval_enum->interval = mode->frame_interval[0];
> +		break;
> +	case MEDIA_BUS_FMT_SBGGR10_1X10:
> +		interval_enum->interval = mode->frame_interval[1];
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_pad_ops ov5648_subdev_pad_ops = {
> +	.enum_mbus_code		= ov5648_enum_mbus_code,
> +	.get_fmt		= ov5648_get_fmt,
> +	.set_fmt		= ov5648_set_fmt,
> +	.enum_frame_size	= ov5648_enum_frame_size,
> +	.enum_frame_interval	= ov5648_enum_frame_interval,
> +};
> +
> +static const struct v4l2_subdev_ops ov5648_subdev_ops = {
> +	.core		= &ov5648_subdev_core_ops,
> +	.video		= &ov5648_subdev_video_ops,
> +	.pad		= &ov5648_subdev_pad_ops,
> +};
> +
> +static int ov5648_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct fwnode_handle *handle;
> +	struct ov5648_sensor *sensor;
> +	struct v4l2_subdev *subdev;
> +	struct media_pad *pad;
> +	int ret;
> +
> +	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
> +	if (!sensor)
> +		return -ENOMEM;
> +
> +	sensor->dev = dev;
> +	sensor->i2c_client = client;
> +
> +	/* Graph Endpoint */
> +
> +	handle = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
> +	if (!handle) {
> +		dev_err(dev, "unable to find enpoint node\n");
> +		return -EINVAL;
> +	}
> +
> +	sensor->endpoint.bus_type = V4L2_MBUS_CSI2_DPHY;
> +
> +	ret = v4l2_fwnode_endpoint_parse(handle, &sensor->endpoint);
> +	fwnode_handle_put(handle);
> +	if (ret) {
> +		dev_err(dev, "failed to parse endpoint node\n");
> +		return ret;
> +	}
> +
> +	/* GPIOs */
> +
> +	sensor->powerdown = devm_gpiod_get_optional(dev, "powerdown",
> +						    GPIOD_OUT_HIGH);
> +	if (IS_ERR(sensor->powerdown))
> +		return PTR_ERR(sensor->powerdown);
> +
> +	sensor->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> +	if (IS_ERR(sensor->reset))
> +		return PTR_ERR(sensor->reset);
> +
> +	/* Regulators */
> +
> +	/* DVDD: digital core */
> +	sensor->dvdd = devm_regulator_get(dev, "dvdd");
> +	if (IS_ERR(sensor->dvdd)) {
> +		dev_err(dev, "cannot get DVDD (digital core) regulator\n");
> +		return PTR_ERR(sensor->dvdd);
> +	}
> +
> +	/* DOVDD: digital I/O */
> +	sensor->dovdd = devm_regulator_get(dev, "dovdd");
> +	if (IS_ERR(sensor->dvdd)) {
> +		dev_err(dev, "cannot get DOVDD (digital I/O) regulator\n");
> +		return PTR_ERR(sensor->dvdd);
> +	}
> +
> +	/* AVDD: analog */
> +	sensor->avdd = devm_regulator_get_optional(dev, "avdd");
> +	if (IS_ERR(sensor->avdd)) {
> +		dev_info(dev, "no AVDD regulator provided, using internal\n");
> +		sensor->avdd = NULL;
> +	}
> +
> +	/* External Clock */
> +
> +	sensor->xvclk = devm_clk_get(dev, "xvclk");
> +	if (IS_ERR(sensor->xvclk)) {
> +		dev_err(dev, "failed to get xvclk external clock\n");
> +		return PTR_ERR(sensor->xvclk);
> +	}
> +
> +	ret = clk_set_rate_exclusive(sensor->xvclk, OV5648_XVCLK_RATE);

The clock rate is specific to the driver, not to the device.

If you rely on assigned-clock-rates, you'll need to get the frequency and
compare that against what the driver can do, and fail if the driver doesn't
support the frequency. I understand this is the preferred method nowadays.

> +	if (ret) {
> +		dev_err(dev, "failed to set xvclk external clock rate\n");
> +		return ret;
> +	}
> +
> +	/* Subdev, entity and pad */
> +
> +	subdev = &sensor->subdev;
> +	v4l2_i2c_subdev_init(subdev, client, &ov5648_subdev_ops);
> +
> +	subdev->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	subdev->entity.function = MEDIA_ENT_F_CAM_SENSOR;
> +
> +	pad = &sensor->pad;
> +	pad->flags = MEDIA_PAD_FL_SOURCE;
> +
> +	ret = media_entity_pads_init(&subdev->entity, 1, pad);
> +	if (ret)
> +		goto error_entity;
> +
> +	/* Mutex */
> +
> +	mutex_init(&sensor->mutex);
> +
> +	/* Sensor */
> +
> +	ret = ov5648_ctrls_init(sensor);
> +	if (ret)
> +		goto error_mutex;
> +
> +	ret = ov5648_state_init(sensor);
> +	if (ret)
> +		goto error_ctrls;
> +
> +	/* V4L2 subdev register */
> +
> +	ret = v4l2_async_register_subdev_sensor_common(subdev);
> +	if (ret)
> +		goto error_ctrls;
> +
> +	return 0;
> +
> +error_ctrls:
> +	v4l2_ctrl_handler_free(&sensor->ctrls.handler);
> +
> +error_mutex:
> +	mutex_destroy(&sensor->mutex);
> +
> +error_entity:
> +	media_entity_cleanup(&sensor->subdev.entity);
> +
> +	return ret;
> +}
> +
> +static int ov5648_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
> +	struct ov5648_sensor *sensor = ov5648_subdev_sensor(subdev);
> +
> +	clk_rate_exclusive_put(sensor->xvclk);
> +
> +	v4l2_async_unregister_subdev(subdev);
> +	mutex_destroy(&sensor->mutex);
> +	media_entity_cleanup(&subdev->entity);
> +	v4l2_device_unregister_subdev(subdev);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id ov5648_id[] = {
> +	{ "ov5648", 0 },

Please don't add I²C ID table unless you really need it. The OF match table
is enough in general.

> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ov5648_id);
> +
> +static const struct of_device_id ov5648_of_match[] = {
> +	{ .compatible = "ovti,ov5648" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, ov5648_of_match);
> +
> +static struct i2c_driver ov5648_driver = {
> +	.driver = {
> +		.of_match_table = ov5648_of_match,
> +		.name	= "ov5648",
> +	},
> +	.probe_new = ov5648_probe,
> +	.remove	 = ov5648_remove,
> +	.id_table = ov5648_id,
> +};
> +
> +module_i2c_driver(ov5648_driver);
> +
> +MODULE_AUTHOR("Paul Kocialkowski <paul.kocialkowski@bootlin.com>");
> +MODULE_DESCRIPTION("V4L2 driver for the OmniVision OV5648 image sensor");
> +MODULE_LICENSE("GPL v2");