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

   1 From 9a111b4b03340341604941cb7611a2b1d16e8edd 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
   5  legacy API
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 Load driver early since at least bcm2708_fb doesn't support deferred
  11 probing and even if it did, we don't want the video driver deferred.
  12 Support the legacy DMA API which is needed by bcm2708_fb.
  13 Don't mask out channel 2.
  14
  15 Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
  16 ---
  17  drivers/dma/Kconfig       |  2 +-
  18  drivers/dma/bcm2835-dma.c | 26 +++++++++++++++++++++++++-
  19  2 files changed, 26 insertions(+), 2 deletions(-)
  20
  21 --- a/drivers/dma/Kconfig
  22 +++ b/drivers/dma/Kconfig
  23 @@ -133,7 +133,7 @@ config COH901318
  24
  25  config DMA_BCM2835
  26         tristate "BCM2835 DMA engine support"
  27 -       depends on ARCH_BCM2835
  28 +       depends on ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709
  29         select DMA_ENGINE
  30         select DMA_VIRTUAL_CHANNELS
  31
  32 --- a/drivers/dma/bcm2835-dma.c
  33 +++ b/drivers/dma/bcm2835-dma.c
  34 @@ -25,6 +25,7 @@
  35  #include <linux/interrupt.h>
  36  #include <linux/list.h>
  37  #include <linux/module.h>
  38 +#include <linux/platform_data/dma-bcm2708.h>
  39  #include <linux/platform_device.h>
  40  #include <linux/slab.h>
  41  #include <linux/io.h>
  42 @@ -36,6 +37,7 @@
  43
  44  #define BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED 14
  45  #define BCM2835_DMA_CHAN_NAME_SIZE 8
  46 +#define BCM2835_DMA_BULK_MASK  BIT(0)
  47
  48  /**
  49   * struct bcm2835_dmadev - BCM2835 DMA controller
  50 @@ -912,6 +914,9 @@ static int bcm2835_dma_probe(struct plat
  51         base = devm_ioremap_resource(&pdev->dev, res);
  52         if (IS_ERR(base))
  53                 return PTR_ERR(base);
  54 +       rc = bcm_dmaman_probe(pdev, base, BCM2835_DMA_BULK_MASK);
  55 +       if (rc)
  56 +               dev_err(&pdev->dev, "Failed to initialize the legacy API\n");
  57
  58         od->base = base;
  59
  60 @@ -957,6 +962,9 @@ static int bcm2835_dma_probe(struct plat
  61                 goto err_no_dma;
  62         }
  63
  64 +       /* Channel 0 is used by the legacy API */
  65 +       chans_available &= ~BCM2835_DMA_BULK_MASK;
  66 +
  67         /* get irqs for each channel that we support */
  68         for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) {
  69                 /* skip masked out channels */
  70 @@ -1031,6 +1039,7 @@ static int bcm2835_dma_remove(struct pla
  71  {
  72         struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
  73
  74 +       bcm_dmaman_remove(pdev);
  75         dma_async_device_unregister(&od->ddev);
  76         bcm2835_dma_free(od);
  77
  78 @@ -1046,7 +1055,22 @@ static struct platform_driver bcm2835_dm
  79         },
  80  };
  81
  82 -module_platform_driver(bcm2835_dma_driver);
  83 +static int bcm2835_dma_init(void)
  84 +{
  85 +       return platform_driver_register(&bcm2835_dma_driver);
  86 +}
  87 +
  88 +static void bcm2835_dma_exit(void)
  89 +{
  90 +       platform_driver_unregister(&bcm2835_dma_driver);
  91 +}
  92 +
  93 +/*
  94 + * Load after serial driver (arch_initcall) so we see the messages if it fails,
  95 + * but before drivers (module_init) that need a DMA channel.
  96 + */
  97 +subsys_initcall(bcm2835_dma_init);
  98 +module_exit(bcm2835_dma_exit);
  99
 100  MODULE_ALIAS("platform:bcm2835-dma");
 101  MODULE_DESCRIPTION("BCM2835 DMA engine driver");