Re: [PATCH 12/14] staging: vc04_services: bcm2835_isp: Allow multiple users

From: Laurent Pinchart
Date: Mon Nov 21 2022 - 18:30:11 EST


Hi Umang and Naush,

Thank you for the patch.

On Tue, Nov 22, 2022 at 03:17:20AM +0530, Umang Jain wrote:
> From: Naushir Patuck <naush@xxxxxxxxxxxxxxx>
>
> Add a second (identical) set of device nodes to allow concurrent use of
> the bcm2835-isp hardware by another user. This change effectively
> creates a second state structure (struct bcm2835_isp_dev) to maintain
> independent state for the second user. Node and media entity names are
> appened with the instance index appropriately.
>
> Further users can be added by changing the BCM2835_ISP_NUM_INSTANCES
> define.
>
> Signed-off-by: Naushir Patuck <naush@xxxxxxxxxxxxxxx>
> Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx>

Let's squash this with 09/14.

> ---
> .../bcm2835-isp/bcm2835-v4l2-isp.c | 77 +++++++++++++++----
> 1 file changed, 61 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/staging/vc04_services/bcm2835-isp/bcm2835-v4l2-isp.c b/drivers/staging/vc04_services/bcm2835-isp/bcm2835-v4l2-isp.c
> index cb7cdba76682..0dbcb25595e7 100644
> --- a/drivers/staging/vc04_services/bcm2835-isp/bcm2835-v4l2-isp.c
> +++ b/drivers/staging/vc04_services/bcm2835-isp/bcm2835-v4l2-isp.c
> @@ -28,13 +28,19 @@
>
> MODULE_IMPORT_NS(DMA_BUF);
>
> +/*
> + * We want to instantiate 2 independent instances allowing 2 simultaneous users
> + * of the ISP hardware.
> + */
> +#define BCM2835_ISP_NUM_INSTANCES 2
> +
> static unsigned int debug;
> module_param(debug, uint, 0644);
> MODULE_PARM_DESC(debug, "activates debug info");
>
> -static unsigned int video_nr = 13;
> -module_param(video_nr, uint, 0644);
> -MODULE_PARM_DESC(video_nr, "base video device number");
> +static unsigned int video_nr[BCM2835_ISP_NUM_INSTANCES] = { 13, 20 };
> +module_param_array(video_nr, uint, NULL, 0644);
> +MODULE_PARM_DESC(video_nr, "base video device numbers");
>
> #define BCM2835_ISP_NAME "bcm2835-isp"
> #define BCM2835_ISP_ENTITY_NAME_LEN 32
> @@ -1286,6 +1292,7 @@ static int bcm2835_isp_get_supported_fmts(struct bcm2835_isp_node *node)
> * or output nodes.
> */
> static int register_node(struct bcm2835_isp_dev *dev,
> + unsigned int instance,
> struct bcm2835_isp_node *node,
> int index)
> {
> @@ -1447,7 +1454,7 @@ static int register_node(struct bcm2835_isp_dev *dev,
> snprintf(vfd->name, sizeof(node->vfd.name), "%s-%s%d", BCM2835_ISP_NAME,
> node->name, node->id);
>
> - ret = video_register_device(vfd, VFL_TYPE_VIDEO, video_nr + index);
> + ret = video_register_device(vfd, VFL_TYPE_VIDEO, video_nr[instance]);
> if (ret) {
> v4l2_err(&dev->v4l2_dev,
> "Failed to register video %s[%d] device node\n",
> @@ -1668,9 +1675,8 @@ static int media_controller_register(struct bcm2835_isp_dev *dev)
> return ret;
> }
>
> -static int bcm2835_isp_remove(struct platform_device *pdev)
> +static void bcm2835_isp_remove_instance(struct bcm2835_isp_dev *dev)
> {
> - struct bcm2835_isp_dev *dev = platform_get_drvdata(pdev);
> unsigned int i;
>
> media_controller_unregister(dev);
> @@ -1685,11 +1691,11 @@ static int bcm2835_isp_remove(struct platform_device *pdev)
> dev->component);
>
> vchiq_mmal_finalise(dev->mmal_instance);
> -
> - return 0;
> }
>
> -static int bcm2835_isp_probe(struct platform_device *pdev)
> +static int bcm2835_isp_probe_instance(struct platform_device *pdev,
> + struct bcm2835_isp_dev **dev_int,
> + unsigned int instance)
> {
> struct bcm2835_isp_dev *dev;
> unsigned int i;
> @@ -1699,6 +1705,7 @@ static int bcm2835_isp_probe(struct platform_device *pdev)
> if (!dev)
> return -ENOMEM;
>
> + *dev_int = dev;
> dev->dev = &pdev->dev;
>
> ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
> @@ -1716,7 +1723,7 @@ static int bcm2835_isp_probe(struct platform_device *pdev)
> if (ret) {
> v4l2_err(&dev->v4l2_dev,
> "%s: failed to create ril.isp component\n", __func__);
> - goto error;
> + return ret;
> }
>
> if (dev->component->inputs < BCM2835_ISP_NUM_OUTPUTS ||
> @@ -1728,7 +1735,7 @@ static int bcm2835_isp_probe(struct platform_device *pdev)
> BCM2835_ISP_NUM_OUTPUTS,
> dev->component->outputs,
> BCM2835_ISP_NUM_CAPTURES + BCM2835_ISP_NUM_METADATA);
> - goto error;
> + return -EINVAL;
> }
>
> atomic_set(&dev->num_streaming, 0);
> @@ -1736,17 +1743,55 @@ static int bcm2835_isp_probe(struct platform_device *pdev)
> for (i = 0; i < BCM2835_ISP_NUM_NODES; i++) {
> struct bcm2835_isp_node *node = &dev->node[i];
>
> - ret = register_node(dev, node, i);
> + ret = register_node(dev, instance, node, i);
> if (ret)
> - goto error;
> + return ret;
> }
>
> ret = media_controller_register(dev);
> if (ret)
> - goto error;
> + return ret;
> +
> + return 0;
> +}
> +
> +static int bcm2835_isp_remove(struct platform_device *pdev)
> +{
> + struct bcm2835_isp_dev **bcm2835_isp_instances;
> + unsigned int i;
> +
> + bcm2835_isp_instances = platform_get_drvdata(pdev);
> + for (i = 0; i < BCM2835_ISP_NUM_INSTANCES; i++) {
> + if (bcm2835_isp_instances[i])
> + bcm2835_isp_remove_instance(bcm2835_isp_instances[i]);
> + }
> +
> + return 0;
> +}
> +
> +static int bcm2835_isp_probe(struct platform_device *pdev)
> +{
> + struct bcm2835_isp_dev **bcm2835_isp_instances;
> + unsigned int i;
> + int ret;
> +
> + bcm2835_isp_instances = devm_kzalloc(&pdev->dev,
> + sizeof(bcm2835_isp_instances) *
> + BCM2835_ISP_NUM_INSTANCES,
> + GFP_KERNEL);
> + if (!bcm2835_isp_instances)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, bcm2835_isp_instances);
> +
> + for (i = 0; i < BCM2835_ISP_NUM_INSTANCES; i++) {
> + ret = bcm2835_isp_probe_instance(pdev,
> + &bcm2835_isp_instances[i], i);
> + if (ret)
> + goto error;
> + }
>
> - platform_set_drvdata(pdev, dev);
> - v4l2_info(&dev->v4l2_dev, "Loaded V4L2 %s\n", BCM2835_ISP_NAME);
> + dev_info(&pdev->dev, "Loaded V4L2 %s\n", BCM2835_ISP_NAME);
> return 0;
>
> error:

--
Regards,

Laurent Pinchart