Re: [PATCH v2 9/9] ipu3-cio2: Parse information from firmware without using callbacks

[Jacopo Mondi <jacopo@jmondi.org>]

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Hi Sakari,

On Thu, Jun 06, 2019 at 04:02:25PM +0300, Sakari Ailus wrote:
> Instead of using the convenience function
> v4l2_async_notifier_parse_fwnode_endpoints(), parse the endpoints and set
> up the async sub-devices without using callbacks. While this adds a little
> bit of code, it makes parsing the endpoints quite a bit more simple and
> gives more control to the driver over the process. The parsing assumes
> D-PHY instead of letting the V4L2 fwnode framework guess it.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>  drivers/media/pci/intel/ipu3/ipu3-cio2.c | 92 +++++++++++++++++---------------
>  1 file changed, 49 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> index 690d3bd08ddd..40e8b8617f55 100644
> --- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> @@ -1475,36 +1475,51 @@ static const struct v4l2_async_notifier_operations cio2_async_ops = {
>  	.complete = cio2_notifier_complete,
>  };
>
> -static int cio2_fwnode_parse(struct device *dev,
> -			     struct v4l2_fwnode_endpoint *vep,
> -			     struct v4l2_async_subdev *asd)
> +static int cio2_parse_firmware(struct cio2_device *cio2)
>  {
> -	struct sensor_async_subdev *s_asd =
> -			container_of(asd, struct sensor_async_subdev, asd);
> +	unsigned int i;
> +	int ret;
>
> -	if (vep->bus_type != V4L2_MBUS_CSI2_DPHY) {
> -		dev_err(dev, "Only CSI2 bus type is currently supported\n");
> -		return -EINVAL;
> -	}
> +	for (i = 0; i < CIO2_NUM_PORTS; i++) {
> +		struct v4l2_fwnode_endpoint vep = {
> +			.bus_type = V4L2_MBUS_CSI2_DPHY
> +		};
> +		struct sensor_async_subdev *s_asd = NULL;
> +		struct fwnode_handle *ep;
>
> -	s_asd->csi2.port = vep->base.port;
> -	s_asd->csi2.lanes = vep->bus.mipi_csi2.num_data_lanes;
> +		ep = fwnode_graph_get_endpoint_by_id(
> +			dev_fwnode(&cio2->pci_dev->dev), i, 0,
> +			FWNODE_GRAPH_ENDPOINT_NEXT);
>
> -	return 0;
> -}
> +		if (!ep)
> +			continue;
>
> -static int cio2_notifier_init(struct cio2_device *cio2)
> -{
> -	int ret;
> +		ret = v4l2_fwnode_endpoint_parse(ep, &vep);
> +		if (ret)
> +			goto err_parse;
>
> -	v4l2_async_notifier_init(&cio2->notifier);
> +		s_asd = kzalloc(sizeof(*s_asd), GFP_KERNEL);
> +		if (!s_asd) {
> +			ret = -ENOMEM;
> +			goto err_parse;
> +		}
>
> -	ret = v4l2_async_notifier_parse_fwnode_endpoints(

How would you feel trying to remove this function completely? There
are only 2 users mainline (rcar-vin and sunxi) and this is 'yet
another way to parse an endpoint and add it to a notifier async list'.

I would say, stabilizing on the use of one of the three
v4l2_async_notifier_add_ versions could be desirable...

> -		&cio2->pci_dev->dev, &cio2->notifier,
> -		sizeof(struct sensor_async_subdev),
> -		cio2_fwnode_parse);
> -	if (ret < 0)
> -		goto out;
> +		s_asd->csi2.port = vep.base.port;
> +		s_asd->csi2.lanes = vep.bus.mipi_csi2.num_data_lanes;
> +
> +		ret = v4l2_async_notifier_add_fwnode_remote_subdev(
> +			&cio2->notifier, ep, &s_asd->asd);
> +		fwnode_handle_put(ep);
> +		if (ret)
> +			goto err_parse;
> +
> +		continue;
> +
> +err_parse:
> +		fwnode_handle_put(ep);

Won't the notifier cleanup put this device node for us?

This apart, for the patch itself:
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

Thanks
  j

> +		kfree(s_asd);
> +		return ret;
> +	}
>
>  	/*
>  	 * Proceed even without sensors connected to allow the device to
> @@ -1512,25 +1527,13 @@ static int cio2_notifier_init(struct cio2_device *cio2)
>  	 */
>  	cio2->notifier.ops = &cio2_async_ops;
>  	ret = v4l2_async_notifier_register(&cio2->v4l2_dev, &cio2->notifier);
> -	if (ret) {
> +	if (ret)
>  		dev_err(&cio2->pci_dev->dev,
>  			"failed to register async notifier : %d\n", ret);
> -		goto out;
> -	}
> -
> -out:
> -	if (ret)
> -		v4l2_async_notifier_cleanup(&cio2->notifier);
>
>  	return ret;
>  }
>
> -static void cio2_notifier_exit(struct cio2_device *cio2)
> -{
> -	v4l2_async_notifier_unregister(&cio2->notifier);
> -	v4l2_async_notifier_cleanup(&cio2->notifier);
> -}
> -
>  /**************** Queue initialization ****************/
>  static const struct media_entity_operations cio2_media_ops = {
>  	.link_validate = v4l2_subdev_link_validate,
> @@ -1814,16 +1817,18 @@ static int cio2_pci_probe(struct pci_dev *pci_dev,
>  	if (r)
>  		goto fail_v4l2_device_unregister;
>
> +	v4l2_async_notifier_init(&cio2->notifier);
> +
>  	/* Register notifier for subdevices we care */
> -	r = cio2_notifier_init(cio2);
> +	r = cio2_parse_firmware(cio2);
>  	if (r)
> -		goto fail_cio2_queue_exit;
> +		goto fail_clean_notifier;
>
>  	r = devm_request_irq(&pci_dev->dev, pci_dev->irq, cio2_irq,
>  			     IRQF_SHARED, CIO2_NAME, cio2);
>  	if (r) {
>  		dev_err(&pci_dev->dev, "failed to request IRQ (%d)\n", r);
> -		goto fail;
> +		goto fail_clean_notifier;
>  	}
>
>  	pm_runtime_put_noidle(&pci_dev->dev);
> @@ -1831,9 +1836,9 @@ static int cio2_pci_probe(struct pci_dev *pci_dev,
>
>  	return 0;
>
> -fail:
> -	cio2_notifier_exit(cio2);
> -fail_cio2_queue_exit:
> +fail_clean_notifier:
> +	v4l2_async_notifier_unregister(&cio2->notifier);
> +	v4l2_async_notifier_cleanup(&cio2->notifier);
>  	cio2_queues_exit(cio2);
>  fail_v4l2_device_unregister:
>  	v4l2_device_unregister(&cio2->v4l2_dev);
> @@ -1852,7 +1857,8 @@ static void cio2_pci_remove(struct pci_dev *pci_dev)
>  	struct cio2_device *cio2 = pci_get_drvdata(pci_dev);
>
>  	media_device_unregister(&cio2->media_dev);
> -	cio2_notifier_exit(cio2);
> +	v4l2_async_notifier_unregister(&cio2->notifier);
> +	v4l2_async_notifier_cleanup(&cio2->notifier);
>  	cio2_queues_exit(cio2);
>  	cio2_fbpt_exit_dummy(cio2);
>  	v4l2_device_unregister(&cio2->v4l2_dev);
> --
> 2.11.0
>

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