target/linux/brcm2708/patches-4.4/0402-dmaengine-bcm2835-Load-driver-early-and-support-lega.patch

   1 From b0ad872cdb56e3dfd36ec2fbd0aad0375609bb0f 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 402/423] 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
  13 Support the legacy DMA API which is needed by bcm2708_fb
  14 (but only using the dedicated dma channel 0).
  15
  16 Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
  17 Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
  18 ---
  19  drivers/dma/Kconfig       |  2 +-
  20  drivers/dma/bcm2835-dma.c | 27 ++++++++++++++++++++++++++-
  21  2 files changed, 27 insertions(+), 2 deletions(-)
  22
  23 --- a/drivers/dma/Kconfig
  24 +++ b/drivers/dma/Kconfig
  25 @@ -108,7 +108,7 @@ config COH901318
  26
  27  config DMA_BCM2835
  28         tristate "BCM2835 DMA engine support"
  29 -       depends on ARCH_BCM2835
  30 +       depends on ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709
  31         select DMA_ENGINE
  32         select DMA_VIRTUAL_CHANNELS
  33
  34 --- a/drivers/dma/bcm2835-dma.c
  35 +++ b/drivers/dma/bcm2835-dma.c
  36 @@ -37,6 +37,7 @@
  37  #include <linux/interrupt.h>
  38  #include <linux/list.h>
  39  #include <linux/module.h>
  40 +#include <linux/platform_data/dma-bcm2708.h>
  41  #include <linux/platform_device.h>
  42  #include <linux/slab.h>
  43  #include <linux/io.h>
  44 @@ -1021,6 +1022,14 @@ static int bcm2835_dma_probe(struct plat
  45
  46         dev_dbg(&pdev->dev, "Load BCM2835 DMA engine driver\n");
  47
  48 +       /* load the legacy api if bit 0 in the mask is cleared */
  49 +       if ((chans_available & BIT(0)) == 0) {
  50 +               rc = bcm_dmaman_probe(pdev, base, BIT(0));
  51 +               if (rc)
  52 +                       dev_err(&pdev->dev,
  53 +                               "Failed to initialize the legacy API\n");
  54 +       }
  55 +
  56         return 0;
  57
  58  err_no_dma:
  59 @@ -1032,6 +1041,7 @@ static int bcm2835_dma_remove(struct pla
  60  {
  61         struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
  62
  63 +       bcm_dmaman_remove(pdev);
  64         dma_async_device_unregister(&od->ddev);
  65         bcm2835_dma_free(od);
  66
  67 @@ -1047,7 +1057,22 @@ static struct platform_driver bcm2835_dm
  68         },
  69  };
  70
  71 -module_platform_driver(bcm2835_dma_driver);
  72 +static int bcm2835_dma_init(void)
  73 +{
  74 +       return platform_driver_register(&bcm2835_dma_driver);
  75 +}
  76 +
  77 +static void bcm2835_dma_exit(void)
  78 +{
  79 +       platform_driver_unregister(&bcm2835_dma_driver);
  80 +}
  81 +
  82 +/*
  83 + * Load after serial driver (arch_initcall) so we see the messages if it fails,
  84 + * but before drivers (module_init) that need a DMA channel.
  85 + */
  86 +subsys_initcall(bcm2835_dma_init);
  87 +module_exit(bcm2835_dma_exit);
  88
  89  MODULE_ALIAS("platform:bcm2835-dma");
  90  MODULE_DESCRIPTION("BCM2835 DMA engine driver");