RE: [PATCH 2/6] media: i2c: Add imx335 camera sensor driver

["Martina Krasteva" <martinax.krasteva@linux.intel.com>]

Hi Sakari,

Thank you for your review. I will address both your and Rob's comments.

I have a question regarding the switch from pm_runtime_get_sync() to pm_runtime_resume_and_get()
In my understanding get_sync() is fine to use in case the error handling is correct, but for convenience resume_and_get() is
recommended.
So should I do this change in my drivers as well? 

Best Regards,
Martina

> 
> Hi Martina,
> 
> Thanks for the a of new drivers. Also my apologies for reviewing them so
> late.
> 
> On Tue, Mar 30, 2021 at 03:20:19PM +0100, Martina Krasteva wrote:
> 
> ...
> > +static int imx335_probe(struct i2c_client *client)
> > +{
> > +	struct imx335 *imx335;
> > +	int ret;
> > +
> > +	imx335 = devm_kzalloc(&client->dev, sizeof(*imx335), GFP_KERNEL);
> > +	if (!imx335)
> > +		return -ENOMEM;
> > +
> > +	imx335->dev = &client->dev;
> > +
> > +	/* Initialize subdev */
> > +	v4l2_i2c_subdev_init(&imx335->sd, client, &imx335_subdev_ops);
> > +
> > +	ret = imx335_parse_hw_config(imx335);
> > +	if (ret) {
> > +		dev_err(imx335->dev, "HW configuration is not supported");
> > +		return ret;
> > +	}
> > +
> > +	mutex_init(&imx335->mutex);
> > +
> > +	ret = imx335_power_on(imx335->dev);
> > +	if (ret) {
> > +		dev_err(imx335->dev, "failed to power-on the sensor");
> > +		goto error_mutex_destroy;
> > +	}
> > +
> > +	/* Check module identity */
> > +	ret = imx335_detect(imx335);
> > +	if (ret) {
> > +		dev_err(imx335->dev, "failed to find sensor: %d", ret);
> > +		goto error_power_off;
> > +	}
> > +
> > +	/* Set default mode to max resolution */
> > +	imx335->cur_mode = &supported_mode;
> > +	imx335->vblank = imx335->cur_mode->vblank;
> > +
> > +	ret = imx335_init_controls(imx335);
> > +	if (ret) {
> > +		dev_err(imx335->dev, "failed to init controls: %d", ret);
> > +		goto error_power_off;
> > +	}
> > +
> > +	/* Initialize subdev */
> > +	imx335->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +	imx335->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > +
> > +	/* Initialize source pad */
> > +	imx335->pad.flags = MEDIA_PAD_FL_SOURCE;
> > +	ret = media_entity_pads_init(&imx335->sd.entity, 1, &imx335->pad);
> > +	if (ret) {
> > +		dev_err(imx335->dev, "failed to init entity pads: %d", ret);
> > +		goto error_handler_free;
> > +	}
> > +
> > +	ret = v4l2_async_register_subdev_sensor_common(&imx335->sd);
> > +	if (ret < 0) {
> > +		dev_err(imx335->dev,
> > +			"failed to register async subdev: %d", ret);
> > +		goto error_media_entity;
> > +	}
> > +
> > +	pm_runtime_set_active(imx335->dev);
> > +	pm_runtime_enable(imx335->dev);
> > +	pm_runtime_idle(imx335->dev);
> > +
> > +	return 0;
> > +
> > +error_media_entity:
> > +	media_entity_cleanup(&imx335->sd.entity);
> > +error_handler_free:
> > +	v4l2_ctrl_handler_free(imx335->sd.ctrl_handler);
> > +error_power_off:
> > +	imx335_power_off(imx335->dev);
> > +error_mutex_destroy:
> > +	mutex_destroy(&imx335->mutex);
> > +
> > +	return ret;
> > +}
> > +
> > +/**
> > + * imx335_remove() - I2C client device unbinding
> > + * @client: pointer to I2C client device
> > + *
> > + * Return: 0 if successful, error code otherwise.
> > + */
> > +static int imx335_remove(struct i2c_client *client)
> > +{
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct imx335 *imx335 = to_imx335(sd);
> > +
> > +	v4l2_async_unregister_subdev(sd);
> > +	media_entity_cleanup(&sd->entity);
> > +	v4l2_ctrl_handler_free(sd->ctrl_handler);
> > +
> > +	pm_runtime_disable(&client->dev);
> > +	pm_runtime_suspended(&client->dev);
> 
> The sensor will be powered off here only if runtime PM is enabled.
> 
> Could you use pm_runtime_status_suspended() to check whether the device is
> still powered on, as e.g. the CCS driver (drivers/media/i2c/ccs/ccs-core.c)
> does?
> 
> I think I'll merge these when this and Rob's comments have been addressed.
> 
> > +
> > +	mutex_destroy(&imx335->mutex);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct dev_pm_ops imx335_pm_ops = {
> > +	SET_RUNTIME_PM_OPS(imx335_power_off, imx335_power_on, NULL)
> > +};
> > +
> > +static const struct of_device_id imx335_of_match[] = {
> > +	{ .compatible = "sony,imx335" },
> > +	{ }
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, imx335_of_match);
> > +
> > +static struct i2c_driver imx335_driver = {
> > +	.probe_new = imx335_probe,
> > +	.remove = imx335_remove,
> > +	.driver = {
> > +		.name = "imx335",
> > +		.pm = &imx335_pm_ops,
> > +		.of_match_table = imx335_of_match,
> > +	},
> > +};
> > +
> > +module_i2c_driver(imx335_driver);
> > +
> > +MODULE_DESCRIPTION("Sony imx335 sensor driver");
> > +MODULE_LICENSE("GPL");
> 
> --
> Kind regards,
> 
> Sakari Ailus