Re: [PATCH v2 8/9] media: i2c: ov08d10: add support for reset and power management

[Sakari Ailus <sakari.ailus@linux.intel.com>]

On Mon, Mar 09, 2026 at 06:07:10PM +0100, Matthias Fend wrote:
> Add support for the required power supplies as well as the control of an
> optional sensor reset.
> 
> Signed-off-by: Matthias Fend <matthias.fend@emfend.at>
> ---
>  drivers/media/i2c/ov08d10.c | 93 ++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 92 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/ov08d10.c b/drivers/media/i2c/ov08d10.c
> index ce0fa30a86129302b5dda0b8796e44054fd77c88..19035991e8bb164d4fca5d87ee4551191974e8bb 100644
> --- a/drivers/media/i2c/ov08d10.c
> +++ b/drivers/media/i2c/ov08d10.c
> @@ -8,6 +8,7 @@
>  #include <linux/module.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/reset.h>
>  #include <media/v4l2-ctrls.h>
>  #include <media/v4l2-device.h>
>  #include <media/v4l2-fwnode.h>
> @@ -513,9 +514,17 @@ static const char * const ov08d10_test_pattern_menu[] = {
>  	"Standard Color Bar",
>  };
>  
> +static const char *const ov08d10_supply_names[] = {
> +	"dovdd",	/* Digital I/O power */
> +	"avdd",		/* Analog power */
> +	"dvdd",		/* Digital core power */
> +};
> +
>  struct ov08d10 {
>  	struct device *dev;
>  	struct clk *clk;
> +	struct reset_control *reset;
> +	struct regulator_bulk_data supplies[ARRAY_SIZE(ov08d10_supply_names)];
>  
>  	struct v4l2_subdev sd;
>  	struct media_pad pad;
> @@ -1265,6 +1274,56 @@ static const struct v4l2_subdev_internal_ops ov08d10_internal_ops = {
>  	.open = ov08d10_open,
>  };
>  
> +static int ov08d10_power_off(struct device *dev)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct ov08d10 *ov08d10 = to_ov08d10(sd);
> +
> +	reset_control_assert(ov08d10->reset);
> +
> +	regulator_bulk_disable(ARRAY_SIZE(ov08d10->supplies),
> +			       ov08d10->supplies);
> +
> +	clk_disable_unprepare(ov08d10->clk);
> +
> +	return 0;
> +}
> +
> +static int ov08d10_power_on(struct device *dev)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct ov08d10 *ov08d10 = to_ov08d10(sd);
> +	int ret;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ov08d10->supplies),
> +				    ov08d10->supplies);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to enable regulators: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(ov08d10->clk);
> +	if (ret < 0) {
> +		regulator_bulk_disable(ARRAY_SIZE(ov08d10->supplies),
> +				       ov08d10->supplies);
> +
> +		dev_err(dev, "failed to enable imaging clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (ov08d10->reset) {
> +		/* Delay from DVDD stable to sensor XSHUTDN pull up: 5ms */
> +		fsleep(5 * USEC_PER_MSEC);
> +
> +		reset_control_deassert(ov08d10->reset);
> +
> +		/* Delay from XSHUTDN pull up to SCCB start: 8ms */
> +		fsleep(8 * USEC_PER_MSEC);
> +	}
> +
> +	return 0;
> +}
> +
>  static int ov08d10_identify_module(struct ov08d10 *ov08d10)
>  {
>  	struct i2c_client *client = v4l2_get_subdevdata(&ov08d10->sd);
> @@ -1371,6 +1430,10 @@ static void ov08d10_remove(struct i2c_client *client)
>  	media_entity_cleanup(&sd->entity);
>  	v4l2_ctrl_handler_free(sd->ctrl_handler);
>  	pm_runtime_disable(ov08d10->dev);
> +	if (!pm_runtime_status_suspended(ov08d10->dev)) {
> +		ov08d10_power_off(ov08d10->dev);
> +		pm_runtime_set_suspended(ov08d10->dev);
> +	}
>  	mutex_destroy(&ov08d10->mutex);
>  }
>  
> @@ -1378,6 +1441,7 @@ static int ov08d10_probe(struct i2c_client *client)
>  {
>  	struct ov08d10 *ov08d10;
>  	unsigned long freq;
> +	unsigned int i;
>  	int ret;
>  
>  	ov08d10 = devm_kzalloc(&client->dev, sizeof(*ov08d10), GFP_KERNEL);
> @@ -1403,12 +1467,32 @@ static int ov08d10_probe(struct i2c_client *client)
>  		return ret;
>  	}
>  
> +	ov08d10->reset = devm_reset_control_get_optional_exclusive(ov08d10->dev, NULL);
> +	if (IS_ERR(ov08d10->reset))
> +		return dev_err_probe(ov08d10->dev, PTR_ERR(ov08d10->reset),
> +				     "failed to get reset\n");
> +	reset_control_assert(ov08d10->reset);
> +
> +	for (i = 0; i < ARRAY_SIZE(ov08d10_supply_names); i++)

You can declare i here.

> +		ov08d10->supplies[i].supply = ov08d10_supply_names[i];
> +
> +	ret = devm_regulator_bulk_get(ov08d10->dev,
> +				      ARRAY_SIZE(ov08d10->supplies),
> +				      ov08d10->supplies);
> +	if (ret)
> +		return dev_err_probe(ov08d10->dev, ret,
> +				     "failed to get regulators\n");
> +
>  	v4l2_i2c_subdev_init(&ov08d10->sd, client, &ov08d10_subdev_ops);
>  
> +	ret = ov08d10_power_on(ov08d10->dev);
> +	if (ret)
> +		return dev_err_probe(ov08d10->dev, ret, "failed to power on\n");
> +
>  	ret = ov08d10_identify_module(ov08d10);
>  	if (ret) {
>  		dev_err(ov08d10->dev, "failed to find sensor: %d\n", ret);
> -		return ret;
> +		goto probe_error_power_off;
>  	}
>  
>  	mutex_init(&ov08d10->mutex);
> @@ -1452,9 +1536,15 @@ static int ov08d10_probe(struct i2c_client *client)
>  	v4l2_ctrl_handler_free(ov08d10->sd.ctrl_handler);
>  	mutex_destroy(&ov08d10->mutex);
>  
> +probe_error_power_off:
> +	ov08d10_power_off(ov08d10->dev);
> +
>  	return ret;
>  }
>  
> +static DEFINE_RUNTIME_DEV_PM_OPS(ov08d10_pm_ops,
> +				 ov08d10_power_off, ov08d10_power_on, NULL);
> +
>  #ifdef CONFIG_ACPI
>  static const struct acpi_device_id ov08d10_acpi_ids[] = {
>  	{ "OVTI08D1" },
> @@ -1473,6 +1563,7 @@ MODULE_DEVICE_TABLE(of, ov08d10_of_match);
>  static struct i2c_driver ov08d10_i2c_driver = {
>  	.driver = {
>  		.name = "ov08d10",
> +		.pm = pm_ptr(&ov08d10_pm_ops),
>  		.acpi_match_table = ACPI_PTR(ov08d10_acpi_ids),
>  		.of_match_table = ov08d10_of_match,
>  	},
> 

-- 
Regards,

Sakari Ailus