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authorNishanth Menon <nm@ti.com>2014-06-12 17:15:22 +0530
committerTony Lindgren <tony@atomide.com>2014-07-21 23:32:51 -0700
commit76be4a54157ab0059fb29d8d516db46d239812e2 (patch)
tree434db5329e5a6facbc1ca84bfac6c20daf9c7972
parent3db53918e306d3960bf9e12eea8b2fd3f7d0fd62 (diff)
downloadlinux-76be4a54157ab0059fb29d8d516db46d239812e2.tar.bz2
ARM: OMAP2+: DMA: remove requirement of irq for platform-dma driver
we have currently 2 DMA drivers that try to co-exist. drivers/dma/omap-dma.c which registers it's own IRQ and is device tree aware and uses arch/arm/plat-omap/dma.c instance created by arch/arm/mach-omap2/dma.c to maintain channel usage (omap_request_dma). Currently both try to register interrupts and mach-omap2/plat-omap dma.c attempts to use the IRQ number registered by hwmod to register it's own interrupt handler. Now, there is no reasonable way of static allocating DMA irq in GIC SPI when we use crossbar. However, since the dma_chan structure is freed as a result of IRQ not being present due to devm allocation, maintaining information of channel by platform code fails at a later point in time when that region of memory is reused. So, if hwmod does not indicate an IRQ number, then, assume that dma-engine will take care of the interrupt handling. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
-rw-r--r--arch/arm/mach-omap2/dma.c3
-rw-r--r--arch/arm/plat-omap/dma.c5
-rw-r--r--include/linux/omap-dma.h1
3 files changed, 7 insertions, 2 deletions
diff --git a/arch/arm/mach-omap2/dma.c b/arch/arm/mach-omap2/dma.c
index a6d2cf1f8d02..e1a56d87599e 100644
--- a/arch/arm/mach-omap2/dma.c
+++ b/arch/arm/mach-omap2/dma.c
@@ -259,6 +259,9 @@ static int __init omap2_system_dma_init_dev(struct omap_hwmod *oh, void *unused)
if (cpu_is_omap34xx() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
d->dev_caps |= HS_CHANNELS_RESERVED;
+ if (platform_get_irq_byname(pdev, "0") < 0)
+ d->dev_caps |= DMA_ENGINE_HANDLE_IRQ;
+
/* Check the capabilities register for descriptor loading feature */
if (dma_read(CAPS_0, 0) & DMA_HAS_DESCRIPTOR_CAPS)
dma_common_ch_end = CCDN;
diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index b5608b1f9fbd..7aae0e5b188c 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -2100,7 +2100,7 @@ static int omap_system_dma_probe(struct platform_device *pdev)
omap_dma_set_global_params(DMA_DEFAULT_ARB_RATE,
DMA_DEFAULT_FIFO_DEPTH, 0);
- if (dma_omap2plus()) {
+ if (dma_omap2plus() && !(d->dev_caps & DMA_ENGINE_HANDLE_IRQ)) {
strcpy(irq_name, "0");
dma_irq = platform_get_irq_byname(pdev, irq_name);
if (dma_irq < 0) {
@@ -2145,7 +2145,8 @@ static int omap_system_dma_remove(struct platform_device *pdev)
char irq_name[4];
strcpy(irq_name, "0");
dma_irq = platform_get_irq_byname(pdev, irq_name);
- remove_irq(dma_irq, &omap24xx_dma_irq);
+ if (dma_irq >= 0)
+ remove_irq(dma_irq, &omap24xx_dma_irq);
} else {
int irq_rel = 0;
for ( ; irq_rel < dma_chan_count; irq_rel++) {
diff --git a/include/linux/omap-dma.h b/include/linux/omap-dma.h
index 88e6ea4a5d36..6f06f8bc612c 100644
--- a/include/linux/omap-dma.h
+++ b/include/linux/omap-dma.h
@@ -130,6 +130,7 @@
#define IS_WORD_16 BIT(0xd)
#define ENABLE_16XX_MODE BIT(0xe)
#define HS_CHANNELS_RESERVED BIT(0xf)
+#define DMA_ENGINE_HANDLE_IRQ BIT(0x10)
/* Defines for DMA Capabilities */
#define DMA_HAS_TRANSPARENT_CAPS (0x1 << 18)