target/linux/brcm2708/patches-4.4/0022-dmaengine-bcm2835-Load-driver-early-and-support-lega.patch

   1 From 1fcc178455d43657d3d7a318dd570b9a091a8708 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 | 30 ++++++++++++++++++++++++------
  18  2 files changed, 25 insertions(+), 7 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 @@ -36,6 +36,7 @@
  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 @@ -786,6 +787,10 @@ static int bcm2835_dma_probe(struct plat
  42         if (IS_ERR(base))
  43                 return PTR_ERR(base);
  44
  45 +       rc = bcm_dmaman_probe(pdev, base, BCM2835_DMA_BULK_MASK);
  46 +       if (rc)
  47 +               dev_err(&pdev->dev, "Failed to initialize the legacy API\n");
  48 +
  49         od->base = base;
  50
  51         dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
  52 @@ -818,11 +823,8 @@ static int bcm2835_dma_probe(struct plat
  53                 goto err_no_dma;
  54         }
  55
  56 -       /*
  57 -        * Do not use the FIQ and BULK channels,
  58 -        * because they are used by the GPU.
  59 -        */
  60 -       chans_available &= ~(BCM2835_DMA_FIQ_MASK | BCM2835_DMA_BULK_MASK);
  61 +       /* Channel 0 is used by the legacy API */
  62 +       chans_available &= ~BCM2835_DMA_BULK_MASK;
  63
  64         for (i = 0; i < pdev->num_resources; i++) {
  65                 irq = platform_get_irq(pdev, i);
  66 @@ -866,6 +868,7 @@ static int bcm2835_dma_remove(struct pla
  67  {
  68         struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
  69
  70 +       bcm_dmaman_remove(pdev);
  71         dma_async_device_unregister(&od->ddev);
  72         bcm2835_dma_free(od);
  73
  74 @@ -881,7 +884,22 @@ static struct platform_driver bcm2835_dm
  75         },
  76  };
  77
  78 -module_platform_driver(bcm2835_dma_driver);
  79 +static int bcm2835_dma_init(void)
  80 +{
  81 +       return platform_driver_register(&bcm2835_dma_driver);
  82 +}
  83 +
  84 +static void bcm2835_dma_exit(void)
  85 +{
  86 +       platform_driver_unregister(&bcm2835_dma_driver);
  87 +}
  88 +
  89 +/*
  90 + * Load after serial driver (arch_initcall) so we see the messages if it fails,
  91 + * but before drivers (module_init) that need a DMA channel.
  92 + */
  93 +subsys_initcall(bcm2835_dma_init);
  94 +module_exit(bcm2835_dma_exit);
  95
  96  MODULE_ALIAS("platform:bcm2835-dma");
  97  MODULE_DESCRIPTION("BCM2835 DMA engine driver");