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authorHans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>2009-04-01 15:47:02 +0200
committerDan Williams <dan.j.williams@intel.com>2009-04-01 15:42:34 -0700
commitd9de451989a88a2003ca06e524aca4665c0c7f06 (patch)
treea926d4ff1b73da88d5112324611a579a94e28095 /drivers/dma/dw_dmac_regs.h
parent0f571515c332e00b3515dbe0859ceaa30ab66e00 (diff)
downloadop-kernel-dev-d9de451989a88a2003ca06e524aca4665c0c7f06.zip
op-kernel-dev-d9de451989a88a2003ca06e524aca4665c0c7f06.tar.gz
dw_dmac: add cyclic API to DW DMA driver
This patch adds a cyclic DMA interface to the DW DMA driver. This is very useful if you want to use the DMA controller in combination with a sound device which uses cyclic buffers. Using a DMA channel for cyclic DMA will disable the possibility to use it as a normal DMA engine until the user calls the cyclic free function on the DMA channel. Also a cyclic DMA list can not be prepared if the channel is already active. Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dma/dw_dmac_regs.h')
-rw-r--r--drivers/dma/dw_dmac_regs.h7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
index b252b20..13a5807 100644
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -126,6 +126,10 @@ struct dw_dma_regs {
#define DW_REGLEN 0x400
+enum dw_dmac_flags {
+ DW_DMA_IS_CYCLIC = 0,
+};
+
struct dw_dma_chan {
struct dma_chan chan;
void __iomem *ch_regs;
@@ -134,10 +138,12 @@ struct dw_dma_chan {
spinlock_t lock;
/* these other elements are all protected by lock */
+ unsigned long flags;
dma_cookie_t completed;
struct list_head active_list;
struct list_head queue;
struct list_head free_list;
+ struct dw_cyclic_desc *cdesc;
unsigned int descs_allocated;
};
@@ -158,7 +164,6 @@ static inline struct dw_dma_chan *to_dw_dma_chan(struct dma_chan *chan)
return container_of(chan, struct dw_dma_chan, chan);
}
-
struct dw_dma {
struct dma_device dma;
void __iomem *regs;
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