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dmaengine: Add DMA_CTRL_REUSE

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This adds new descriptor flag for reusing a descriptor by submitting
multiple times by a client, for example video buffer.
Add helper APIs for this as well

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by:Robert Jarzmik <robert.jarzmik@free.fr>
This commit is contained in:
Vinod Koul 2015-08-05 08:42:05 +05:30
parent 60884ddecd
commit 272420214d
1 changed files with 40 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

40
include/linux/dmaengine.h
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@ -184,6 +184,8 @@ struct dma_interleaved_template {
* operation it continues the calculation with new sources
* @DMA_PREP_FENCE - tell the driver that subsequent operations depend
* on the result of this operation
* @DMA_CTRL_REUSE: client can reuse the descriptor and submit again till
* cleared or freed
*/
enum dma_ctrl_flags {
DMA_PREP_INTERRUPT = (1 << 0),
@ -192,6 +194,7 @@ enum dma_ctrl_flags {
DMA_PREP_PQ_DISABLE_Q = (1 << 3),
DMA_PREP_CONTINUE = (1 << 4),
DMA_PREP_FENCE = (1 << 5),
DMA_CTRL_REUSE = (1 << 6),
};
/**
@ -401,6 +404,8 @@ enum dma_residue_granularity {
* @cmd_pause: true, if pause and thereby resume is supported
* @cmd_terminate: true, if terminate cmd is supported
* @residue_granularity: granularity of the reported transfer residue
* @descriptor_reuse: if a descriptor can be reused by client and
* resubmitted multiple times
*/
struct dma_slave_caps {
u32 src_addr_widths;
@ -409,6 +414,7 @@ struct dma_slave_caps {
bool cmd_pause;
bool cmd_terminate;
enum dma_residue_granularity residue_granularity;
bool descriptor_reuse;
};
static inline const char *dma_chan_name(struct dma_chan *chan)
@ -468,6 +474,7 @@ struct dma_async_tx_descriptor {
dma_addr_t phys;
struct dma_chan *chan;
dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
int (*desc_free)(struct dma_async_tx_descriptor *tx);
dma_async_tx_callback callback;
void *callback_param;
struct dmaengine_unmap_data *unmap;
@ -1175,6 +1182,39 @@ static inline int dma_get_slave_caps(struct dma_chan *chan,
}
#endif
static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx)
{
struct dma_slave_caps caps;
dma_get_slave_caps(tx->chan, &caps);
if (caps.descriptor_reuse) {
tx->flags |= DMA_CTRL_REUSE;
return 0;
} else {
return -EPERM;
}
}
static inline void dmaengine_desc_clear_reuse(struct dma_async_tx_descriptor *tx)
{
tx->flags &= ~DMA_CTRL_REUSE;
}
static inline bool dmaengine_desc_test_reuse(struct dma_async_tx_descriptor *tx)
{
return (tx->flags & DMA_CTRL_REUSE) == DMA_CTRL_REUSE;
}
static inline int dmaengine_desc_free(struct dma_async_tx_descriptor *desc)
{
/* this is supported for reusable desc, so check that */
if (dmaengine_desc_test_reuse(desc))
return desc->desc_free(desc);
else
return -EPERM;
}
/* --- DMA device --- */
int dma_async_device_register(struct dma_device *device);