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

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Umang Jain <umang.jain@ideasonboard.com>
Cc: linux-media@vger.kernel.org, kernel-list@raspberrypi.com,
	linux-kernel@vger.kernel.org,
	linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-staging@lists.linux.dev,
	Broadcom internal kernel review list
	<bcm-kernel-feedback-list@broadcom.com>,
	Dave Stevenson <dave.stevenson@raspberrypi.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Naushir Patuck <naush@raspberrypi.com>,
	David Plowman <david.plowman@raspberrypi.com>,
	Kieran Bingham <kieran.bingham@ideasonboard.com>
Subject: Re: [PATCH 12/14] staging: vc04_services: bcm2835_isp: Allow multiple users
Date: Tue, 22 Nov 2022 01:35:47 +0200	[thread overview]
Message-ID: <Y3wLUwfOn0TzndZe@pendragon.ideasonboard.com> (raw)
In-Reply-To: <Y3wJ6/+Hl6JTm1Bu@pendragon.ideasonboard.com>

On Tue, Nov 22, 2022 at 01:29:48AM +0200, Laurent Pinchart wrote:
> 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@raspberrypi.com>
> > 
> > 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@raspberrypi.com>
> > Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> 
> Let's squash this with 09/14.

Also, the documentation in 13/14 should be updated.

> > ---
> >  .../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