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

   1 From 8da7ee8d9b714dbbac842fb5ae0471b52e0393ec 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 022/170] 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 | 30 ++++++++++++++++++++++++------
  19  2 files changed, 25 insertions(+), 7 deletions(-)
  20
  21 --- a/drivers/dma/Kconfig
  22 +++ b/drivers/dma/Kconfig
  23 @@ -108,7 +108,7 @@ 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 @@ -36,6 +36,7 @@
  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 @@ -786,6 +787,10 @@ static int bcm2835_dma_probe(struct plat
  43         if (IS_ERR(base))
  44                 return PTR_ERR(base);
  45
  46 +       rc = bcm_dmaman_probe(pdev, base, BCM2835_DMA_BULK_MASK);
  47 +       if (rc)
  48 +               dev_err(&pdev->dev, "Failed to initialize the legacy API\n");
  49 +
  50         od->base = base;
  51
  52         dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
  53 @@ -818,11 +823,8 @@ static int bcm2835_dma_probe(struct plat
  54                 goto err_no_dma;
  55         }
  56
  57 -       /*
  58 -        * Do not use the FIQ and BULK channels,
  59 -        * because they are used by the GPU.
  60 -        */
  61 -       chans_available &= ~(BCM2835_DMA_FIQ_MASK | BCM2835_DMA_BULK_MASK);
  62 +       /* Channel 0 is used by the legacy API */
  63 +       chans_available &= ~BCM2835_DMA_BULK_MASK;
  64
  65         for (i = 0; i < pdev->num_resources; i++) {
  66                 irq = platform_get_irq(pdev, i);
  67 @@ -866,6 +868,7 @@ static int bcm2835_dma_remove(struct pla
  68  {
  69         struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
  70
  71 +       bcm_dmaman_remove(pdev);
  72         dma_async_device_unregister(&od->ddev);
  73         bcm2835_dma_free(od);
  74
  75 @@ -881,7 +884,22 @@ static struct platform_driver bcm2835_dm
  76         },
  77  };
  78
  79 -module_platform_driver(bcm2835_dma_driver);
  80 +static int bcm2835_dma_init(void)
  81 +{
  82 +       return platform_driver_register(&bcm2835_dma_driver);
  83 +}
  84 +
  85 +static void bcm2835_dma_exit(void)
  86 +{
  87 +       platform_driver_unregister(&bcm2835_dma_driver);
  88 +}
  89 +
  90 +/*
  91 + * Load after serial driver (arch_initcall) so we see the messages if it fails,
  92 + * but before drivers (module_init) that need a DMA channel.
  93 + */
  94 +subsys_initcall(bcm2835_dma_init);
  95 +module_exit(bcm2835_dma_exit);
  96
  97  MODULE_ALIAS("platform:bcm2835-dma");
  98  MODULE_DESCRIPTION("BCM2835 DMA engine driver");