git.openwrt.org Git - openwrt/openwrt.git/blob

   1 From e4f0f7daebca7005c67bf7ae3f6f59df587e91d5 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
   3 Date: Sat, 3 Oct 2015 22:22:55 +0200
   4 Subject: [PATCH] dmaengine: bcm2835: Load driver early and support legacy API
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Load driver early since at least bcm2708_fb doesn't support deferred
  10 probing and even if it did, we don't want the video driver deferred.
  11 Support the legacy DMA API which is needed by bcm2708_fb.
  12 Don't mask out channel 2.
  13
  14 Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
  15 ---
  16  drivers/dma/Kconfig       |  2 +-
  17  drivers/dma/bcm2835-dma.c | 26 +++++++++++++++++++++++++-
  18  2 files changed, 26 insertions(+), 2 deletions(-)
  19
  20 --- a/drivers/dma/Kconfig
  21 +++ b/drivers/dma/Kconfig
  22 @@ -108,7 +108,7 @@ config COH901318
  23
  24  config DMA_BCM2835
  25         tristate "BCM2835 DMA engine support"
  26 -       depends on ARCH_BCM2835
  27 +       depends on ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709
  28         select DMA_ENGINE
  29         select DMA_VIRTUAL_CHANNELS
  30
  31 --- a/drivers/dma/bcm2835-dma.c
  32 +++ b/drivers/dma/bcm2835-dma.c
  33 @@ -37,6 +37,7 @@
  34  #include <linux/interrupt.h>
  35  #include <linux/list.h>
  36  #include <linux/module.h>
  37 +#include <linux/platform_data/dma-bcm2708.h>
  38  #include <linux/platform_device.h>
  39  #include <linux/slab.h>
  40  #include <linux/io.h>
  41 @@ -48,6 +49,7 @@
  42
  43  #define BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED 14
  44  #define BCM2835_DMA_CHAN_NAME_SIZE 8
  45 +#define BCM2835_DMA_BULK_MASK  BIT(0)
  46
  47  struct bcm2835_dmadev {
  48         struct dma_device ddev;
  49 @@ -925,6 +927,9 @@ static int bcm2835_dma_probe(struct plat
  50         base = devm_ioremap_resource(&pdev->dev, res);
  51         if (IS_ERR(base))
  52                 return PTR_ERR(base);
  53 +       rc = bcm_dmaman_probe(pdev, base, BCM2835_DMA_BULK_MASK);
  54 +       if (rc)
  55 +               dev_err(&pdev->dev, "Failed to initialize the legacy API\n");
  56
  57         od->base = base;
  58
  59 @@ -962,6 +967,9 @@ static int bcm2835_dma_probe(struct plat
  60                 goto err_no_dma;
  61         }
  62
  63 +       /* Channel 0 is used by the legacy API */
  64 +       chans_available &= ~BCM2835_DMA_BULK_MASK;
  65 +
  66         /* get irqs for each channel that we support */
  67         for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) {
  68                 /* skip masked out channels */
  69 @@ -1036,6 +1044,7 @@ static int bcm2835_dma_remove(struct pla
  70  {
  71         struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
  72
  73 +       bcm_dmaman_remove(pdev);
  74         dma_async_device_unregister(&od->ddev);
  75         bcm2835_dma_free(od);
  76
  77 @@ -1051,7 +1060,22 @@ static struct platform_driver bcm2835_dm
  78         },
  79  };
  80
  81 -module_platform_driver(bcm2835_dma_driver);
  82 +static int bcm2835_dma_init(void)
  83 +{
  84 +       return platform_driver_register(&bcm2835_dma_driver);
  85 +}
  86 +
  87 +static void bcm2835_dma_exit(void)
  88 +{
  89 +       platform_driver_unregister(&bcm2835_dma_driver);
  90 +}
  91 +
  92 +/*
  93 + * Load after serial driver (arch_initcall) so we see the messages if it fails,
  94 + * but before drivers (module_init) that need a DMA channel.
  95 + */
  96 +subsys_initcall(bcm2835_dma_init);
  97 +module_exit(bcm2835_dma_exit);
  98
  99  MODULE_ALIAS("platform:bcm2835-dma");
 100  MODULE_DESCRIPTION("BCM2835 DMA engine driver");