Em Tue, 6 Jun 2017 16:37:41 -0700
Kevin Hilman <khilman@xxxxxxxxxxxx> escreveu:
> The davinci VPIF is a single hardware block, but the existing driver
> is broken up into a common library (vpif.c), output (vpif_display.c) and
> intput (vpif_capture.c).
>
> When migrating to DT, to better model the hardware, and because
> registers, interrupts, etc. are all common,it was decided to
> have a single VPIF hardware node[1].
>
> Because davinci uses legacy, non-DT boot on several SoCs still, the
> platform_drivers need to remain. But they are also needed in DT boot.
> Since there are no DT nodes for the display/capture parts in DT
> boot (there is a single node for the parent/common device) we need to
> create platform_devices somewhere to instansiate the platform_drivers.
>
> When VPIF display/capture are needed for a DT boot, the VPIF node
> will have endpoints defined for its subdevs. Therefore, vpif_probe()
> checks for the presence of endpoints, and if detected manually creates
> the platform_devices for the display and capture platform_drivers.
>
> [1] Documentation/devicetree/bindings/media/ti,da850-vpif.txt
>
> Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
> ---
> drivers/media/platform/davinci/vpif.c | 49 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 48 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/davinci/vpif.c b/drivers/media/platform/davinci/vpif.c
> index 1b02a6363f77..502917abcb13 100644
> --- a/drivers/media/platform/davinci/vpif.c
> +++ b/drivers/media/platform/davinci/vpif.c
> @@ -26,6 +26,7 @@
> #include <linux/pm_runtime.h>
> #include <linux/spinlock.h>
> #include <linux/v4l2-dv-timings.h>
> +#include <linux/of_graph.h>
>
> #include "vpif.h"
>
> @@ -423,7 +424,9 @@ EXPORT_SYMBOL(vpif_channel_getfid);
>
> static int vpif_probe(struct platform_device *pdev)
> {
> - static struct resource *res;
> + static struct resource *res, *res_irq;
> + struct platform_device *pdev_capture, *pdev_display;
> + struct device_node *endpoint = NULL;
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> vpif_base = devm_ioremap_resource(&pdev->dev, res);
> @@ -435,6 +438,50 @@ static int vpif_probe(struct platform_device *pdev)
>
> spin_lock_init(&vpif_lock);
> dev_info(&pdev->dev, "vpif probe success\n");
> +
> + /*
> + * If VPIF Node has endpoints, assume "new" DT support,
> + * where capture and display drivers don't have DT nodes
> + * so their devices need to be registered manually here
> + * for their legacy platform_drivers to work.
> + */
> + endpoint = of_graph_get_next_endpoint(pdev->dev.of_node,
> + endpoint);
> + if (!endpoint)
> + return 0;
> +
> + /*
> + * For DT platforms, manually create platform_devices for
> + * capture/display drivers.
> + */
> + res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + if (!res_irq) {
> + dev_warn(&pdev->dev, "Missing IRQ resource.\n");
> + return -EINVAL;
> + }
> +
> + pdev_capture = devm_kzalloc(&pdev->dev, sizeof(*pdev_capture),
> + GFP_KERNEL);
You need to check if it won't return NULL here...
> + pdev_capture->name = "vpif_capture";
> + pdev_capture->id = -1;
> + pdev_capture->resource = res_irq;
> + pdev_capture->num_resources = 1;
> + pdev_capture->dev.dma_mask = pdev->dev.dma_mask;
> + pdev_capture->dev.coherent_dma_mask = pdev->dev.coherent_dma_mask;
> + pdev_capture->dev.parent = &pdev->dev;
> + platform_device_register(pdev_capture);
> +
> + pdev_display = devm_kzalloc(&pdev->dev, sizeof(*pdev_display),
> + GFP_KERNEL);
and here.
Ok, in thesis, if size is lower than page size, it shouldn't fail,
but we still want to have an explicit check[1].
[1] https://lwn.net/Articles/723317/
Thanks,
Mauro
