Hi Michael,
On Thu, Jan 12, 2023 at 02:58:20PM +0100, Michael Tretter wrote:
> On Fri, 06 Jan 2023 15:32:23 +0200, Laurent Pinchart wrote:
> > Register a media device for the PXP, using the v4l2-mem2mem MC
> > infrastructure to populate the media graph. No media device operation is
> > implemented, the main use of the MC API is to allow consistent discovery
> > of media devices for userspace.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > ---
> > drivers/media/platform/nxp/imx-pxp.c | 37 ++++++++++++++++++++++++++++
> > 1 file changed, 37 insertions(+)
> >
> > diff --git a/drivers/media/platform/nxp/imx-pxp.c b/drivers/media/platform/nxp/imx-pxp.c
> > index dcb04217288b..132065c8b8b4 100644
> > --- a/drivers/media/platform/nxp/imx-pxp.c
> > +++ b/drivers/media/platform/nxp/imx-pxp.c
> > @@ -24,6 +24,7 @@
> > #include <linux/sched.h>
> > #include <linux/slab.h>
> >
> > +#include <media/media-device.h>
> > #include <media/v4l2-ctrls.h>
> > #include <media/v4l2-device.h>
> > #include <media/v4l2-event.h>
> > @@ -200,6 +201,9 @@ struct pxp_pdata {
> > struct pxp_dev {
> > struct v4l2_device v4l2_dev;
> > struct video_device vfd;
> > +#ifdef CONFIG_MEDIA_CONTROLLER
> > + struct media_device mdev;
> > +#endif
> >
> > struct clk *clk;
> > void __iomem *mmio;
> > @@ -1832,8 +1836,36 @@ static int pxp_probe(struct platform_device *pdev)
> > goto err_m2m;
> > }
> >
> > +#ifdef CONFIG_MEDIA_CONTROLLER
> > + dev->mdev.dev = &pdev->dev;
> > + strscpy(dev->mdev.model, MEM2MEM_NAME, sizeof(dev->mdev.model));
> > + snprintf(dev->mdev.bus_info, sizeof(dev->mdev.bus_info), "platform:%s",
> > + dev_name(&pdev->dev));
>
> v4l2-compliance gives the following warning:
>
> warn: v4l2-compliance.cpp(642): media bus_info 'platform:30700000.pxp' differs from V4L2 bus_info 'platform:pxp'
>
> I would change this patch to use the same name as in the V4L2 bus_info. Do you
> have a reason for including the address in the bus_info?
Actually, I should drop bus_info here. The documentation of
media_device_init() states
* The bus_info field is set by media_device_init() for PCI and platform devices
* if the field begins with '\0'.
media_device_init() calls media_set_bus_info() which is defined as
/**
* media_set_bus_info() - Set bus_info field
*
* @bus_info: Variable where to write the bus info (char array)
* @bus_info_size: Length of the bus_info
* @dev: Related struct device
*
* Sets bus information based on &dev. This is currently done for PCI and
* platform devices. dev is required to be non-NULL for this to happen.
*
* This function is not meant to be called from drivers.
*/
static inline void
media_set_bus_info(char *bus_info, size_t bus_info_size, struct device *dev)
{
if (!dev)
strscpy(bus_info, "no bus info", bus_info_size);
else if (dev_is_platform(dev))
snprintf(bus_info, bus_info_size, "platform:%s", dev_name(dev));
else if (dev_is_pci(dev))
snprintf(bus_info, bus_info_size, "PCI:%s", dev_name(dev));
}
v4l_querycap() also calls media_set_bus_info(). Including the device
name is thus the recommended option.
I'll include in v2 another patch that drops the bus_info from the
video_device to make v4l2-compliance happy.
> > + media_device_init(&dev->mdev);
> > + dev->v4l2_dev.mdev = &dev->mdev;
> > +
> > + ret = v4l2_m2m_register_media_controller(dev->m2m_dev, vfd,
> > + MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER);
> > + if (ret) {
> > + dev_err(&pdev->dev, "Failed to initialize media device\n");
> > + goto err_vfd;
> > + }
> > +
> > + ret = media_device_register(&dev->mdev);
> > + if (ret) {
> > + dev_err(&pdev->dev, "Failed to register media device\n");
> > + goto err_m2m_mc;
> > + }
> > +#endif
> > +
> > return 0;
> >
> > +#ifdef CONFIG_MEDIA_CONTROLLER
> > +err_m2m_mc:
> > + v4l2_m2m_unregister_media_controller(dev->m2m_dev);
> > +err_vfd:
> > + video_unregister_device(vfd);
> > +#endif
> > err_m2m:
> > v4l2_m2m_release(dev->m2m_dev);
> > err_v4l2:
> > @@ -1854,6 +1886,11 @@ static int pxp_remove(struct platform_device *pdev)
> > clk_disable_unprepare(dev->clk);
> >
> > v4l2_info(&dev->v4l2_dev, "Removing " MEM2MEM_NAME);
> > +
> > +#ifdef CONFIG_MEDIA_CONTROLLER
> > + media_device_unregister(&dev->mdev);
> > + v4l2_m2m_unregister_media_controller(dev->m2m_dev);
> > +#endif
> > video_unregister_device(&dev->vfd);
> > v4l2_m2m_release(dev->m2m_dev);
> > v4l2_device_unregister(&dev->v4l2_dev);
--
Regards,
Laurent Pinchart
