Re: [PATCH v1 3/5] media: i2c: imx492: driver's source

Kieran Bingham
2022-11-28T12:59:08Z

Quoting Petko Manolov (2022-11-25 15:31:18)
> imx492 is a diagonal 23.1 mm (Type 1.4) CMOS image sensor with color or
> monochrome square pixel array and approximately 47.08 M effective pixels. 12-bit
> digital output makes it possible to output the signals with high definition for
> moving pictures. It is programmable through I2C interface. The I2C client
> address can be either 0x10 or 0x1a depending on SLASEL pin. Image data is sent
> through MIPI CSI-2.
>
> Signed-off-by: Petko Manolov <petko.manolov@konsulko.com>
> ---
> drivers/media/i2c/imx492.c | 1092 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 1092 insertions(+)
> create mode 100644 drivers/media/i2c/imx492.c
>
> diff --git a/drivers/media/i2c/imx492.c b/drivers/media/i2c/imx492.c
> new file mode 100644
> index 000000000000..0713256b4b63
> --- /dev/null
> +++ b/drivers/media/i2c/imx492.c
> @@ -0,0 +1,1092 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Sony imx492 Camera Sensor Driver (based on imx412.c source);
> + *
> + * Copyright (C) 2022 Petko Manolov <petko.manolov@konsulko.com>
> + */
> +
> +#include <asm/unaligned.h>
> +
> +#include <linux/clk.h>
> +#include <linux/delay.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-fwnode.h>
> +#include <media/v4l2-subdev.h>
> +
> +#include "imx492.h"
> +
> +/* Streaming Mode */
> +#define IMX492_REG_MODE_SELECT 0x3000
> +
> +/* Chip ID */
> +#define IMX492_ID 0x13

This seems ... surprising to me.

> +
> +/* Analog gain control */
> +#define IMX492_REG_AGAIN 0x300a
> +#define IMX492_AGAIN_MIN 0
> +#define IMX492_AGAIN_MAX 978
> +#define IMX492_AGAIN_STEP 1
> +#define IMX492_AGAIN_DEFAULT 0
> +
> +/* Group hold register */
> +#define IMX492_REG_HOLD 0x302b
> +#define IMX492_REG_XMSTA 0x3033
> +#define IMX492_REG_SYSCLKEN 0x35e5
> +
> +/* CSI2 HW configuration */
> +#define IMX492_LINK_FREQ 745000000
> +#define IMX492_NUM_DATA_LANES 4
> +
> +#define IMX492_REG_MIN 0x3000
> +#define IMX492_REG_MAX 0xffff
> +
> +/* *** */
> +
> +#define IMX492_REG_STANDBY IMX492_REG_MODE_SELECT

Is it a standby register? or a mode select register ?

> +#define IMX492_BIT_STANDBY 0x01
> +#define IMX492_BIT_STBLOGIC 0x02
> +#define IMX492_BIT_STBDV 0x10
> +
> +#define IMX492_MODE_STANDBY (IMX492_BIT_STBDV | IMX492_BIT_STBLOGIC | IMX492_BIT_STANDBY)
> +#define IMX492_MODE_STREAMING 0x00
> +
> +#define IMX492_REG_TESTPTRN 0x303A
> +#define IMX492_BIT_CLKEN 0x01
> +#define IMX492_BIT_TESTPTRN 0x10
> +#define IMX492_BITS_TPTRN_ON (IMX492_BIT_TESTPTRN | IMX492_BIT_CLKEN)
> +#define IMX492_BITS_TPTRN_OFF 0x00
> +
> +#define IMX492_REG_TESTPATSEL 0x303B
> +#define IMX492_BIT_TPAT00 0x00
> +#define IMX492_BIT_TPAT01 0x01
> +#define IMX492_BIT_TPAT02 0x02
> +#define IMX492_BIT_TPAT03 0x03
> +#define IMX492_BIT_TPAT0A 0x0A
> +#define IMX492_BIT_TPAT0B 0x0B
> +
> +#define IMX492_EXPOSURE_MIN 8
> +#define IMX492_EXPOSURE_OFFSET 22
> +#define IMX492_EXPOSURE_STEP 1
> +#define IMX492_EXPOSURE_DEFAULT 0x0648
> +
> +#define DEFAULT_FPS 6
> +
> +/**
> + * struct imx492_reg_list - imx492 sensor register list
> + * @num_of_regs: Number of registers in the list
> + * @regs: Pointer to register list
> + */
> +struct imx492_reg_list {
> + u32 num_of_regs;
> + const struct imx492_reg *regs;
> +};
> +
> +/**
> + * struct imx492_mode - imx492 sensor mode structure
> + * @width: Frame width
> + * @height: Frame height
> + * @code: Format code
> + * @hblank: Horizontal blanking in lines
> + * @vblank: Vertical blanking in lines
> + * @vblank_min: Minimum vertical blanking in lines
> + * @vblank_max: Maximum vertical blanking in lines
> + * @pclk: Sensor pixel clock
> + * @link_freq_idx: Link frequency index
> + * @reg_list: Register list for sensor mode
> + */
> +struct imx492_mode {
> + u32 width;
> + u32 height;
> + u32 code;
> + u32 hblank;
> + u32 hblank_min;
> + u32 hblank_max;
> + u32 vblank;
> + u32 vblank_min;
> + u32 vblank_max;
> + u64 pclk;
> + u32 link_freq_idx;
> + struct imx492_reg_list reg_list;
> +};
> +
> +/**
> + * struct imx492 - imx492 sensor device structure
> + * @dev: Pointer to generic device
> + * @client: Pointer to i2c client
> + * @sd: V4L2 sub-device
> + * @pad: Media pad. Only one pad supported
> + * @reset_gpio: Sensor reset gpio
> + * @reset_gpio: Sensor power gpio
> + * @inclk: Sensor input clock
> + * @supplies: Regulator supplies
> + * @ctrl_handler: V4L2 control handler
> + * @link_freq_ctrl: Pointer to link frequency control
> + * @pclk_ctrl: Pointer to pixel clock control
> + * @hblank_ctrl: Pointer to horizontal blanking control
> + * @vblank_ctrl: Pointer to vertical blanking control
> + * @exp_ctrl: Pointer to exposure control
> + * @again_ctrl: Pointer to analog gain control
> + * @vblank: Vertical blanking in lines
> + * @cur_mode: Pointer to current selected sensor mode
> + * @mutex: Mutex for serializing sensor controls
> + * @streaming: Flag indicating streaming state
> + */
> +struct imx492 {
> + struct device *dev;
> + struct i2c_client *client;
> + struct v4l2_subdev sd;
> + struct media_pad pad;
> + struct v4l2_captureparm scap;
> + struct gpio_desc *reset_gpio;
> + struct gpio_desc *power_gpio;
> + struct gpio_desc *oscen_gpio;
> + struct clk *inclk;
> + struct v4l2_ctrl_handler ctrl_handler;
> + struct v4l2_ctrl *link_freq_ctrl;
> + struct v4l2_ctrl *pclk_ctrl;
> + struct v4l2_ctrl *hblank_ctrl;
> + struct v4l2_ctrl *vblank_ctrl;
> + struct v4l2_ctrl *exp_ctrl;
> + struct v4l2_ctrl *again_ctrl;
> + const struct imx492_mode *cur_mode;
> + struct mutex mutex;
> + u32 tpatt;
> + u32 vblank;
> + bool streaming;
> +};
> +
> +static const s64 link_freq[] = {
> + IMX492_LINK_FREQ,
> +};
> +
> +
> +/* Supported sensor mode configurations */
> +static const struct imx492_mode supported_modes[] = {
> + {
> + .width = 8192,
> + .height = 4320,
> + .hblank = 1108,
> + .hblank_min = 1102,
> + .hblank_max = 32768,
> + .vblank = 5728,
> + .vblank_min = 4428,
> + .vblank_max = 32768,
> + .pclk = 745000000,
> + .link_freq_idx = 0,
> + .code = MEDIA_BUS_FMT_SGBRG12_1X12,
> + .reg_list = {
> + .num_of_regs = ARRAY_SIZE(mode_17to9_regs),
> + .regs = mode_17to9_regs,
> + },
> + }, {
> + .width = 8192,
> + .height = 5556,
> + .hblank = 1108,
> + .hblank_min = 1102,
> + .hblank_max = 32768,
> + .vblank = 5728,
> + .vblank_min = 4428,
> + .vblank_max = 32768,
> + .pclk = 745000000,
> + .link_freq_idx = 0,
> + .code = MEDIA_BUS_FMT_SGBRG12_1X12,
> + .reg_list = {
> + .num_of_regs = ARRAY_SIZE(mode_all_regs),
> + .regs = mode_all_regs,
> + },
> + },
> +};
> +
> +static const char * const imx492_test_pattern_menu[] = {
> + "Disabled",
> + "Solid black",
> + "Solid white",
> + "Solid dark grey",
> + "Solid light gray",
> + "None",
> + "None",
> + "None",
> + "None",
> + "None",
> + "None",

Why so many 'none' entries. Can this be improved?

> + "Vertical color bars",
> + "Horizontal color bars",
> +};
> +
> +/**
> + * to_imx492() - imx492 V4L2 sub-device to imx492 device.
> + * @subdev: pointer to imx492 V4L2 sub-device
> + *
> + * Return: pointer to imx492 device
> + */
> +static inline struct imx492 *to_imx492(struct v4l2_subdev *subdev)
> +{
> + return container_of(subdev, struct imx492, sd);
> +}
> +
> +/**
> + * imx492_read_reg() - Read registers.
> + * @imx492: pointer to imx492 device
> + * @reg: register address
> + * @len: length of bytes to read. Max supported bytes is 4
> + * @val: pointer to register value to be filled.
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_read_reg(struct imx492 *imx492, u16 reg, u32 len, u32 *val)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&imx492->sd);
> + struct i2c_msg msgs[2] = {0};
> + u8 addr_buf[2] = {0};
> + u8 data_buf[4] = {0};
> + int ret;
> +
> + if (WARN_ON(len > 4))
> + return -EINVAL;
> +
> + put_unaligned_be16(reg, addr_buf);
> +
> + /* Write register address */
> + msgs[0].addr = client->addr;
> + msgs[0].flags = 0;
> + msgs[0].len = ARRAY_SIZE(addr_buf);
> + msgs[0].buf = addr_buf;
> +
> + /* Read data from register */
> + msgs[1].addr = client->addr;
> + msgs[1].flags = I2C_M_RD;
> + msgs[1].len = len;
> + msgs[1].buf = &data_buf[4 - len];
> +
> + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> + if (ret != ARRAY_SIZE(msgs))
> + return -EIO;
> +
> + *val = get_unaligned_be32(data_buf);
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_write_reg() - Write register
> + * @imx492: pointer to imx492 device
> + * @reg: register address
> + * @len: length of bytes. Max supported bytes is 4
> + * @val: register value
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_write_reg(struct imx492 *imx492, u16 reg, u32 len, u32 val)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&imx492->sd);
> + u8 buf[6] = {0};
> +
> + if (WARN_ON(len > 4))
> + return -EINVAL;
> +
> + put_unaligned_be16(reg, buf);
> + put_unaligned_be32(val << (8 * (4 - len)), buf + 2);
> + if (i2c_master_send(client, buf, len + 2) != len + 2)
> + return -EIO;
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_write_regs() - Write a list of registers
> + * @imx492: pointer to imx492 device
> + * @regs: list of registers to be written
> + * @len: length of registers array
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_write_regs(struct imx492 *imx492,
> + const struct imx492_reg *regs, u32 len)
> +{
> + unsigned int i;
> + int ret;
> +
> + for (i = 0; i < len; i++) {
> + ret = imx492_write_reg(imx492, regs[i].address, 1, regs[i].val);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static u32 imx492_get_format_code(struct imx492 *imx492, u32 code)
> +{
> + /* for now this is the only format we support */
> + return MEDIA_BUS_FMT_SGBRG12_1X12;
> +}
> +
> +/**
> + * imx492_update_controls() - Update control ranges based on streaming mode
> + * @imx492: pointer to imx492 device
> + * @mode: pointer to imx492_mode sensor mode
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_update_controls(struct imx492 *imx492,
> + const struct imx492_mode *mode)
> +{
> + int ret;
> +
> + ret = __v4l2_ctrl_s_ctrl(imx492->link_freq_ctrl, mode->link_freq_idx);
> + if (ret)
> + return ret;
> +
> + ret = __v4l2_ctrl_s_ctrl(imx492->hblank_ctrl, mode->hblank);
> + if (ret)
> + return ret;
> +
> + return __v4l2_ctrl_modify_range(imx492->vblank_ctrl, mode->vblank_min,
> + mode->vblank_max, 1, mode->vblank);
> +}
> +
> +/**
> + * imx492_update_exp_gain() - Set updated exposure and gain
> + * @imx492: pointer to imx492 device
> + * @exposure: updated exposure value
> + * @gain: updated analog gain value
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_update_exp_gain(struct imx492 *imx492, u32 exposure, u32 gain)
> +{
> + u32 lpfr, shutter;
> + int ret;
> +
> + lpfr = imx492->vblank + imx492->cur_mode->height;
> + shutter = lpfr - exposure;
> +
> + ret = imx492_write_reg(imx492, IMX492_REG_HOLD, 1, 1);
> + if (ret)
> + return ret;
> +
> + ret = imx492_write_reg(imx492, IMX492_REG_AGAIN, 2, gain);
> +
> + return ret;
> +}
> +
> +/**
> + * imx492_set_ctrl() - Set subdevice control
> + * @ctrl: pointer to v4l2_ctrl structure
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct imx492 *imx492 =
> + container_of(ctrl->handler, struct imx492, ctrl_handler);
> + u32 analog_gain;
> + u32 exposure;
> + int ret;
> +
> + switch (ctrl->id) {
> + case V4L2_CID_VBLANK:
> + imx492->vblank = imx492->vblank_ctrl->val;
> +
> + ret = __v4l2_ctrl_modify_range(imx492->exp_ctrl,
> + IMX492_EXPOSURE_MIN,
> + imx492->vblank +
> + imx492->cur_mode->height -
> + IMX492_EXPOSURE_OFFSET,
> + 1, IMX492_EXPOSURE_DEFAULT);
> + break;
> + case V4L2_CID_EXPOSURE:
> + /* Set controls only if sensor is in power on state */
> + if (!pm_runtime_get_if_in_use(imx492->dev))
> + return 0;
> + exposure = ctrl->val;
> + analog_gain = imx492->again_ctrl->val;
> + ret = imx492_update_exp_gain(imx492, exposure, analog_gain);
> + pm_runtime_put(imx492->dev);
> + break;
> + case V4L2_CID_TEST_PATTERN:
> + if (ctrl->val) {
> + imx492_write_reg(imx492, IMX492_REG_TESTPATSEL, 1, ctrl->val - 1);
> + imx492_write_reg(imx492, IMX492_REG_TESTPTRN, 1, IMX492_BITS_TPTRN_ON);
> + } else {
> + imx492_write_reg(imx492, IMX492_REG_TESTPTRN, 1, IMX492_BITS_TPTRN_OFF);
> + }
> + ret = 0;
> + break;
> + default:
> + dev_err(imx492->dev, "Invalid control %d", ctrl->id);
> + ret = -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> +/* V4l2 subdevice control ops*/
> +static const struct v4l2_ctrl_ops imx492_ctrl_ops = {
> + .s_ctrl = imx492_set_ctrl,
> +};
> +
> +/**
> + * imx492_enum_mbus_code() - Enumerate V4L2 sub-device mbus codes
> + * @sd: pointer to imx492 V4L2 sub-device structure
> + * @sd_state: V4L2 sub-device configuration
> + * @code: V4L2 sub-device code enumeration need to be filled
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_enum_mbus_code(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_mbus_code_enum *code)
> +{
> + if (code->index > ARRAY_SIZE(supported_modes))
> + return -EINVAL;
> +
> + code->code = supported_modes[code->index].code;
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_enum_frame_size() - Enumerate V4L2 sub-device frame sizes
> + * @sd: pointer to imx492 V4L2 sub-device structure
> + * @sd_state: V4L2 sub-device configuration
> + * @fsize: V4L2 sub-device size enumeration need to be filled
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_enum_frame_size(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_frame_size_enum *fsize)
> +{
> + if (fsize->index > ARRAY_SIZE(supported_modes))
> + return -EINVAL;
> +
> + if (fsize->code != supported_modes[fsize->index].code)
> + return -EINVAL;
> +
> + fsize->max_width = supported_modes[fsize->index].width;
> + fsize->min_width = fsize->max_width;
> + fsize->max_height = supported_modes[fsize->index].height;
> + fsize->min_height = fsize->max_height;
> +
> + return 0;
> +}
> +
> +/**
> +n * imx492_fill_pad_format() - Fill subdevice pad format
> + * from selected sensor mode
> + * @imx492: pointer to imx492 device
> + * @mode: pointer to imx492_mode sensor mode
> + * @fmt: V4L2 sub-device format need to be filled
> + */
> +static void imx492_fill_pad_format(struct imx492 *imx492,
> + const struct imx492_mode *mode,
> + struct v4l2_subdev_format *fmt)
> +{
> + fmt->format.width = mode->width;
> + fmt->format.height = mode->height;
> + fmt->format.code = mode->code;
> + fmt->format.field = V4L2_FIELD_NONE;
> + fmt->format.colorspace = V4L2_COLORSPACE_RAW;
> + fmt->format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> + fmt->format.quantization = V4L2_QUANTIZATION_DEFAULT;
> + fmt->format.xfer_func = V4L2_XFER_FUNC_NONE;
> +}
> +
> +/**
> + * imx492_get_pad_format() - Get subdevice pad format
> + * @sd: pointer to imx492 V4L2 sub-device structure
> + * @sd_state: V4L2 sub-device configuration
> + * @fmt: V4L2 sub-device format need to be set
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_get_pad_format(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_format *fmt)
> +{
> + struct imx492 *imx492 = to_imx492(sd);
> +
> + mutex_lock(&imx492->mutex);
> +
> + if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
> + struct v4l2_mbus_framefmt *framefmt;
> +
> + framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
> + fmt->format = *framefmt;
> + } else {
> + imx492_fill_pad_format(imx492, imx492->cur_mode, fmt);
> + }
> +
> + mutex_unlock(&imx492->mutex);
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_set_pad_format() - Set subdevice pad format
> + * @sd: pointer to imx492 V4L2 sub-device structure
> + * @sd_state: V4L2 sub-device configuration
> + * @fmt: V4L2 sub-device format need to be set
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_set_pad_format(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_format *fmt)
> +{
> + struct imx492 *imx492 = to_imx492(sd);
> + const struct imx492_mode *mode;
> + int ret = 0;
> +
> + mutex_lock(&imx492->mutex);
> +
> + fmt->format.code = imx492_get_format_code(imx492, 0);
> + mode = v4l2_find_nearest_size(supported_modes,
> + ARRAY_SIZE(supported_modes),
> + width, height,
> + fmt->format.width, fmt->format.height);
> + imx492_fill_pad_format(imx492, mode, fmt);
> +
> + if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
> + struct v4l2_mbus_framefmt *framefmt;
> +
> + framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
> + *framefmt = fmt->format;
> + } else {
> + ret = imx492_update_controls(imx492, mode);
> + if (!ret)
> + imx492->cur_mode = mode;
> + }
> +
> + mutex_unlock(&imx492->mutex);
> +
> + return ret;
> +}
> +
> +/**
> + * imx492_init_pad_cfg() - Initialize sub-device pad configuration
> + * @sd: pointer to imx492 V4L2 sub-device structure
> + * @sd_state: V4L2 sub-device configuration
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_init_pad_cfg(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state)
> +{
> + struct imx492 *imx492 = to_imx492(sd);
> + struct v4l2_subdev_format fmt = { 0 };
> +
> + fmt.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
> + imx492_fill_pad_format(imx492, &supported_modes[0], &fmt);
> +
> + return imx492_set_pad_format(sd, sd_state, &fmt);
> +}
> +
> +/**
> + * imx492_start_streaming() - Start sensor stream
> + * @imx492: pointer to imx492 device
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_start_streaming(struct imx492 *imx492)
> +{
> + const struct imx492_reg_list *reg_list;
> + int ret;
> +
> + /* Write sensor mode registers */
> + reg_list = &imx492->cur_mode->reg_list;
> + ret = imx492_write_regs(imx492, reg_list->regs,
> + reg_list->num_of_regs);
> + if (ret) {
> + dev_err(imx492->dev, "fail to write initial registers");
> + return ret;
> + }
> +
> + /* Setup handler will write actual exposure and gain */
> + ret = __v4l2_ctrl_handler_setup(imx492->sd.ctrl_handler);
> + if (ret) {
> + dev_err(imx492->dev, "fail to setup handler");
> + return ret;
> + }
> +
> + /* 1st stabilization period */
> + usleep_range(10000, 11000);
> + imx492_write_reg(imx492, IMX492_REG_MODE_SELECT, 1, 0x02);
> + imx492_write_reg(imx492, IMX492_REG_SYSCLKEN, 1, 0x92);
> + imx492_write_reg(imx492, IMX492_REG_SYSCLKEN, 1, 0x9a);
> + imx492_write_reg(imx492, IMX492_REG_MODE_SELECT, 1, IMX492_MODE_STREAMING);
> +
> + /* 2nd stabilization period */
> + usleep_range(7000, 8000);
> +
> + /* Start streaming */
> + ret = imx492_write_reg(imx492, IMX492_REG_XMSTA, 1, 0x20);
> +
> + if (ret) {
> + dev_err(imx492->dev, "fail to start streaming");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_stop_streaming() - Stop sensor stream
> + * @imx492: pointer to imx492 device
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static void imx492_stop_streaming(struct imx492 *imx492)
> +{
> + imx492_write_reg(imx492, IMX492_REG_MODE_SELECT, 1, IMX492_MODE_STANDBY);
> + imx492_write_reg(imx492, IMX492_REG_XMSTA, 1, 0x10);
> +}
> +
> +/**
> + * imx492_set_stream() - Enable sensor streaming
> + * @sd: pointer to imx492 subdevice
> + * @enable: set to enable sensor streaming
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_set_stream(struct v4l2_subdev *sd, int enable)
> +{
> + struct imx492 *imx492 = to_imx492(sd);
> + int ret;
> +
> + mutex_lock(&imx492->mutex);
> +
> + if (imx492->streaming == enable) {
> + mutex_unlock(&imx492->mutex);
> + return 0;
> + }
> +
> + if (enable) {
> + ret = pm_runtime_resume_and_get(imx492->dev);
> + if (ret)
> + goto error_unlock;
> + ret = imx492_start_streaming(imx492);
> + if (ret)
> + goto error_power_off;
> + } else {
> + imx492_stop_streaming(imx492);
> + pm_runtime_put(imx492->dev);
> + }
> +
> + imx492->streaming = enable;
> +
> + mutex_unlock(&imx492->mutex);
> +
> + return 0;
> +
> +error_power_off:
> + pm_runtime_put(imx492->dev);
> +error_unlock:
> + mutex_unlock(&imx492->mutex);
> +
> + return ret;
> +}
> +
> +/**
> + * imx492_detect() - Detect imx492 sensor
> + * @imx492: pointer to imx492 device
> + *
> + * Return: 0 if successful, -EIO if sensor id does not match
> + */
> +static int imx492_detect(struct imx492 *imx492)
> +{
> + int ret;
> + u32 val;
> +
> + ret = imx492_read_reg(imx492, IMX492_REG_STANDBY, 1, &val);

This seems an odd register to read for the ID?

And why is it mapped to IMX492_REG_MODE_SELECT ?
How does this give us the ID?

> + if (ret)
> + return ret;
> +
> + if (val != IMX492_ID) {

And seeing other IMX sensors, I would have expected the IMX492_ID to be
0x0492 ?

What is the contents of register 0x0016 ?

> + dev_err(imx492->dev, "chip id mismatch: %x!=%x", IMX492_ID, val);
> + return -ENXIO;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_parse_hw_config() - Parse HW configuration and check if supported
> + * @imx492: pointer to imx492 device
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_parse_hw_config(struct imx492 *imx492)
> +{
> + struct fwnode_handle *fwnode = dev_fwnode(imx492->dev);
> + struct v4l2_fwnode_endpoint bus_cfg = {
> + .bus_type = V4L2_MBUS_CSI2_DPHY
> + };
> + struct fwnode_handle *ep;
> + unsigned int i;
> + int ret;
> +
> + if (!fwnode)
> + return -ENXIO;
> +
> + imx492->power_gpio = devm_gpiod_get(imx492->dev, "power", GPIOD_OUT_HIGH);
> + if (IS_ERR(imx492->power_gpio)) {
> + dev_err(imx492->dev, "failed to get power gpio %ld",
> + PTR_ERR(imx492->power_gpio));
> + return PTR_ERR(imx492->power_gpio);
> + }
> +
> + imx492->oscen_gpio = devm_gpiod_get(imx492->dev, "oscen", GPIOD_OUT_HIGH);
> + if (IS_ERR(imx492->oscen_gpio)) {
> + dev_err(imx492->dev, "failed to get oscen gpio %ld",
> + PTR_ERR(imx492->oscen_gpio));
> + return PTR_ERR(imx492->oscen_gpio);
> + }
> +
> + imx492->reset_gpio = devm_gpiod_get(imx492->dev, "reset", GPIOD_OUT_HIGH);
> + if (IS_ERR(imx492->reset_gpio)) {
> + dev_err(imx492->dev, "failed to get reset gpio %ld",
> + PTR_ERR(imx492->reset_gpio));
> + return PTR_ERR(imx492->reset_gpio);
> + }
> +
> + if (gpiod_direction_output(imx492->power_gpio, 1) ||
> + gpiod_direction_output(imx492->oscen_gpio, 1) ||
> + gpiod_direction_output(imx492->reset_gpio, 0)) {
> + dev_err(imx492->dev, "failed to change gpio direction");
> + return -EINVAL;
> + }
> +
> + /* Get sensor input clock */
> + imx492->inclk = devm_clk_get(imx492->dev, NULL);
> + if (IS_ERR(imx492->inclk)) {
> + dev_err(imx492->dev, "could not get inclk");
> + return PTR_ERR(imx492->inclk);
> + }
> +
> + ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
> + if (!ep) {
> + dev_err(imx492->dev, "next endpoint?");
> + return -ENXIO;
> + }
> +
> + ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
> + fwnode_handle_put(ep);
> + if (ret) {
> + dev_err(imx492->dev, "endpoint alloc parse");
> + return ret;
> + }
> +
> + if (bus_cfg.bus.mipi_csi2.num_data_lanes != IMX492_NUM_DATA_LANES) {
> + dev_err(imx492->dev, "number of CSI2 data lanes %d is not supported",
> + bus_cfg.bus.mipi_csi2.num_data_lanes);
> + ret = -EINVAL;
> + goto done_endpoint_free;
> + }
> +
> + if (!bus_cfg.nr_of_link_frequencies) {
> + dev_err(imx492->dev, "no link frequencies defined");
> + ret = -EINVAL;
> + goto done_endpoint_free;
> + }
> +
> + for (i = 0; i < bus_cfg.nr_of_link_frequencies; i++) {
> + if (bus_cfg.link_frequencies[i] == IMX492_LINK_FREQ)
> + goto done_endpoint_free;
> + }
> +
> + ret = -EINVAL;
> +
> +done_endpoint_free:
> + v4l2_fwnode_endpoint_free(&bus_cfg);
> +
> + return ret;
> +}
> +
> +/* V4l2 subdevice ops */
> +static const struct v4l2_subdev_video_ops imx492_video_ops = {
> + .s_stream = imx492_set_stream,
> +};
> +
> +static const struct v4l2_subdev_pad_ops imx492_pad_ops = {
> + .init_cfg = imx492_init_pad_cfg,
> + .enum_mbus_code = imx492_enum_mbus_code,
> + .enum_frame_size = imx492_enum_frame_size,
> + .get_fmt = imx492_get_pad_format,
> + .set_fmt = imx492_set_pad_format,
> +};
> +
> +static const struct v4l2_subdev_ops imx492_subdev_ops = {
> + .video = &imx492_video_ops,
> + .pad = &imx492_pad_ops,
> +};
> +
> +/**
> + * imx492_power_on() - Sensor power on sequence
> + * @dev: pointer to i2c device
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_power_on(struct device *dev)
> +{
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct imx492 *imx492 = to_imx492(sd);
> +
> + gpiod_set_value_cansleep(imx492->power_gpio, 1);
> + msleep(1);
> + gpiod_set_value_cansleep(imx492->reset_gpio, 1);
> + msleep(1);
> + gpiod_set_value_cansleep(imx492->oscen_gpio, 1);
> + msleep(1);
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_power_off() - Sensor power off sequence
> + * @dev: pointer to i2c device
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_power_off(struct device *dev)
> +{
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct imx492 *imx492 = to_imx492(sd);
> +
> + gpiod_set_value_cansleep(imx492->oscen_gpio, 0);
> + gpiod_set_value_cansleep(imx492->reset_gpio, 0);
> + gpiod_set_value_cansleep(imx492->power_gpio, 0);
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_init_controls() - Initialize sensor subdevice controls
> + * @imx492: pointer to imx492 device
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_init_controls(struct imx492 *imx492)
> +{
> + struct v4l2_ctrl_handler *ctrl_hdlr = &imx492->ctrl_handler;
> + const struct imx492_mode *mode = imx492->cur_mode;
> + u32 lpfr;
> + int ret;
> +
> + ret = v4l2_ctrl_handler_init(ctrl_hdlr, 6);
> + if (ret)
> + return ret;
> +
> + /* Serialize controls with sensor device */
> + ctrl_hdlr->lock = &imx492->mutex;
> + /* Initialize exposure and gain */
> + lpfr = mode->vblank + mode->height;
> + imx492->exp_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> + &imx492_ctrl_ops,
> + V4L2_CID_EXPOSURE,
> + IMX492_EXPOSURE_MIN,
> + lpfr - IMX492_EXPOSURE_OFFSET,
> + IMX492_EXPOSURE_STEP,
> + IMX492_EXPOSURE_DEFAULT);
> +
> + imx492->again_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> + &imx492_ctrl_ops,
> + V4L2_CID_ANALOGUE_GAIN,
> + IMX492_AGAIN_MIN,
> + IMX492_AGAIN_MAX,
> + IMX492_AGAIN_STEP,
> + IMX492_AGAIN_DEFAULT);
> +
> + v4l2_ctrl_cluster(2, &imx492->exp_ctrl);
> +
> + imx492->vblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> + &imx492_ctrl_ops,
> + V4L2_CID_VBLANK,
> + mode->vblank_min,
> + mode->vblank_max,
> + 1, mode->vblank);
> + /* Read only controls */
> + imx492->hblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> + &imx492_ctrl_ops,
> + V4L2_CID_HBLANK,
> + mode->hblank_min,
> + mode->hblank_max,
> + 1, mode->hblank);
> + if (imx492->hblank_ctrl)
> + imx492->hblank_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> + imx492->pclk_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
> + &imx492_ctrl_ops,
> + V4L2_CID_PIXEL_RATE,
> + mode->pclk, mode->pclk,
> + 1, mode->pclk);
> +
> + imx492->link_freq_ctrl = v4l2_ctrl_new_int_menu(ctrl_hdlr,
> + &imx492_ctrl_ops,
> + V4L2_CID_LINK_FREQ,
> + ARRAY_SIZE(link_freq) -
> + 1,
> + mode->link_freq_idx,
> + link_freq);
> + if (imx492->link_freq_ctrl)
> + imx492->link_freq_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
> + v4l2_ctrl_new_std_menu_items(ctrl_hdlr, &imx492_ctrl_ops,
> + V4L2_CID_TEST_PATTERN,
> + ARRAY_SIZE(imx492_test_pattern_menu) - 1,
> + 0, 0, imx492_test_pattern_menu);
> +
> + if (ctrl_hdlr->error) {
> + dev_err(imx492->dev, "control init failed: %d", ctrl_hdlr->error);
> + v4l2_ctrl_handler_free(ctrl_hdlr);
> + return ctrl_hdlr->error;
> + }
> +
> + imx492->sd.ctrl_handler = ctrl_hdlr;
> +
> + return 0;
> +}
> +
> +/**
> + * imx492_probe() - I2C client device binding
> + * @client: pointer to i2c client device
> + *
> + * Return: 0 if successful, error code otherwise.
> + */
> +static int imx492_probe(struct i2c_client *client)
> +{
> + struct imx492 *imx492;
> + int ret;
> +
> + imx492 = devm_kzalloc(&client->dev, sizeof(*imx492), GFP_KERNEL);
> + if (!imx492)
> + return -ENOMEM;
> +
> + imx492->dev = &client->dev;
> +
> + /* Initialize subdev */
> + v4l2_i2c_subdev_init(&imx492->sd, client, &imx492_subdev_ops);
> +
> + ret = imx492_parse_hw_config(imx492);
> + if (ret) {
> + dev_err(imx492->dev, "HW configuration is not supported");
> + return ret;
> + }
> +
> + mutex_init(&imx492->mutex);
> +
> + ret = imx492_power_on(imx492->dev);
> + if (ret) {
> + dev_err(imx492->dev, "failed to power-on the sensor");
> + goto error_mutex_destroy;
> + }
> +
> + /* Check module identity */
> + ret = imx492_detect(imx492);
> + if (ret) {
> + dev_err(imx492->dev, "failed to find sensor: %d", ret);
> + goto error_power_off;
> + }
> +
> + /* Set default mode to max resolution */
> + imx492->cur_mode = &supported_modes[0];
> + imx492->vblank = imx492->cur_mode->vblank;
> +
> + ret = imx492_init_controls(imx492);
> + if (ret) {
> + dev_err(imx492->dev, "failed to init controls: %d", ret);
> + goto error_power_off;
> + }
> +
> + /* Initialize subdev */
> + imx492->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> + imx492->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> +
> + imx492->scap.capability = V4L2_MODE_HIGHQUALITY | V4L2_CAP_TIMEPERFRAME;
> + imx492->scap.capturemode = 0;
> + imx492->scap.timeperframe.denominator = DEFAULT_FPS;
> + imx492->scap.timeperframe.numerator = 1;
> +
> + /* Initialize source pad */
> + imx492->pad.flags = MEDIA_PAD_FL_SOURCE;
> + ret = media_entity_pads_init(&imx492->sd.entity, 1, &imx492->pad);
> + if (ret) {
> + dev_err(imx492->dev, "failed to init entity pads: %d", ret);
> + goto error_handler_free;
> + }
> +
> + ret = v4l2_async_register_subdev(&imx492->sd);
> + if (ret < 0) {
> + dev_err(imx492->dev, "failed to register async subdev: %d", ret);
> + goto error_media_entity;
> + }
> +
> + pm_runtime_set_active(imx492->dev);
> + pm_runtime_enable(imx492->dev);
> + pm_runtime_idle(imx492->dev);
> +
> + return 0;
> +
> +error_media_entity:
> + media_entity_cleanup(&imx492->sd.entity);
> +error_handler_free:
> + v4l2_ctrl_handler_free(imx492->sd.ctrl_handler);
> +error_power_off:
> + imx492_power_off(imx492->dev);
> +error_mutex_destroy:
> + mutex_destroy(&imx492->mutex);
> +
> + return ret;
> +}
> +
> +/**
> + * imx492_remove() - I2C client device unbinding
> + * @client: pointer to I2C client device
> + */
> +static void imx492_remove(struct i2c_client *client)
> +{
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct imx492 *imx492 = to_imx492(sd);
> +
> + v4l2_async_unregister_subdev(sd);
> + media_entity_cleanup(&sd->entity);
> + v4l2_ctrl_handler_free(sd->ctrl_handler);
> + pm_runtime_disable(&client->dev);
> + if (!pm_runtime_status_suspended(&client->dev))
> + imx492_power_off(&client->dev);
> + pm_runtime_set_suspended(&client->dev);
> + mutex_destroy(&imx492->mutex);
> +}
> +
> +static const struct dev_pm_ops imx492_pm_ops = {
> + SET_RUNTIME_PM_OPS(imx492_power_off, imx492_power_on, NULL)
> +};
> +
> +static const struct of_device_id imx492_of_match[] = {
> + { .compatible = "sony,imx492_mipi" },

This doesn't match the bindings. I think the _mipi should just be
removed.

> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(of, imx492_of_match);
> +
> +static struct i2c_driver imx492_driver = {
> + .probe_new = imx492_probe,
> + .remove = imx492_remove,
> + .driver = {
> + .name = "imx492",
> + .pm = &imx492_pm_ops,
> + .of_match_table = imx492_of_match,
> + },
> +};
> +
> +module_i2c_driver(imx492_driver);
> +
> +MODULE_DESCRIPTION("Sony imx492 sensor driver");
> +MODULE_AUTHOR("Petko Manolov <petko.manolov@konsulko.com>");
> +MODULE_LICENSE("GPL");
> --
> 2.30.2
>