dmaengine: Introduce min burst length capability

Some hardware aside from default 0/1 may have greater minimum burst transactions length constraints. Here we introduce the DMA device and slave capability, which if required can be initialized by the DMA engine driver with the device-specific value.

Serge Semin committed 6 years ago

Commit d97758e1 parent 2e7d7422 files · +5 −0Browse files

Showing the changes to include/linux (1 of 2 files). Show all

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include/linux/dmaengine.h+4−0

@@ -467,6 +467,7 @@ enum dma_residue_granularity { · 466 unmodified lines
467	467	* Since the enum dma_transfer_direction is not defined as bit flag for
468	468	* each type, the dma controller should set BIT(<TYPE>) and same
469	469	* should be checked by controller as well
	470	+ * @min_burst: min burst capability per-transfer
470	471	* @max_burst: max burst capability per-transfer
471	472	* @cmd_pause: true, if pause is supported (i.e. for reading residue or
472	473	* for resume later)
@@ -480,6 +481,7 @@ struct dma_slave_caps { · 7 unmodified lines
480	481	u32 src_addr_widths;
481	482	u32 dst_addr_widths;
482	483	u32 directions;
	484	+ u32 min_burst;
483	485	u32 max_burst;
484	486	bool cmd_pause;
485	487	bool cmd_resume;
@@ -771,6 +773,7 @@ struct dma_filter { · 285 unmodified lines
771	773	* Since the enum dma_transfer_direction is not defined as bit flag for
772	774	* each type, the dma controller should set BIT(<TYPE>) and same
773	775	* should be checked by controller as well
	776	+ * @min_burst: min burst capability per-transfer
774	777	* @max_burst: max burst capability per-transfer
775	778	* @residue_granularity: granularity of the transfer residue reported
776	779	* by tx_status
@@ -841,6 +844,7 @@ struct dma_device { · 64 unmodified lines
841	844	u32 src_addr_widths;
842	845	u32 dst_addr_widths;
843	846	u32 directions;
	847	+ u32 min_burst;
844	848	u32 max_burst;
845	849	bool descriptor_reuse;
846	850	enum dma_residue_granularity residue_granularity;