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dmaengine: bcm2835: Load driver early and support legacy API

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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>
This commit is contained in:
Noralf Trønnes
2015-10-03 22:22:55 +02:00
committed by popcornmix
parent c19aeba26d
commit 21cccebc63
2 changed files with 26 additions and 2 deletions
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2
drivers/dma/Kconfig
View File

@@ -133,7 +133,7 @@ config COH901318
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

26
drivers/dma/bcm2835-dma.c
View File

@@ -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");