dmaengine: bcm2835: Load driver early and support legacy API

Load driver early since at least bcm2708_fb doesn't support deferred
probing and even if it did, we don't want the video driver deferred.
Support the legacy DMA API which is needed by bcm2708_fb.
Don't mask out channel 2.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 80c2c03..f5afe0e 100644 (file)
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -127,7 +127,7 @@ config BCM_SBA_RAID
 
 config DMA_BCM2835
        tristate "BCM2835 DMA engine support"
-       depends on ARCH_BCM2835
+       depends on ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709
        select DMA_ENGINE
        select DMA_VIRTUAL_CHANNELS
 

diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 630dfbb..bf7ba96 100644 (file)
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -25,6 +25,7 @@
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/module.h>
+#include <linux/platform_data/dma-bcm2708.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/io.h>
@@ -36,6 +37,7 @@
 
 #define BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED 14
 #define BCM2835_DMA_CHAN_NAME_SIZE 8
+#define BCM2835_DMA_BULK_MASK  BIT(0)
 
 /**
  * struct bcm2835_dmadev - BCM2835 DMA controller
@@ -906,6 +908,9 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
        base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(base))
                return PTR_ERR(base);
+       rc = bcm_dmaman_probe(pdev, base, BCM2835_DMA_BULK_MASK);
+       if (rc)
+               dev_err(&pdev->dev, "Failed to initialize the legacy API\n");
 
        od->base = base;
 
@@ -951,6 +956,9 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
                goto err_no_dma;
        }
 
+       /* Channel 0 is used by the legacy API */
+       chans_available &= ~BCM2835_DMA_BULK_MASK;
+
        /* get irqs for each channel that we support */
        for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) {
                /* skip masked out channels */
@@ -1025,6 +1033,7 @@ static int bcm2835_dma_remove(struct platform_device *pdev)
 {
        struct bcm2835_dmadev *od = platform_get_drvdata(pdev);
 
+       bcm_dmaman_remove(pdev);
        dma_async_device_unregister(&od->ddev);
        bcm2835_dma_free(od);
 
@@ -1040,7 +1049,22 @@ static struct platform_driver bcm2835_dma_driver = {
        },
 };
 
-module_platform_driver(bcm2835_dma_driver);
+static int bcm2835_dma_init(void)
+{
+       return platform_driver_register(&bcm2835_dma_driver);
+}
+
+static void bcm2835_dma_exit(void)
+{
+       platform_driver_unregister(&bcm2835_dma_driver);
+}
+
+/*
+ * Load after serial driver (arch_initcall) so we see the messages if it fails,
+ * but before drivers (module_init) that need a DMA channel.
+ */
+subsys_initcall(bcm2835_dma_init);
+module_exit(bcm2835_dma_exit);
 
 MODULE_ALIAS("platform:bcm2835-dma");
 MODULE_DESCRIPTION("BCM2835 DMA engine driver");