On Thu, May 08, 2014 at 01:49:20PM +0400, Alexander Popov wrote:

quoted

quoted

+     case DMA_SLAVE_CONFIG:
+             /*
+              * Constraints:
+              *  - only transfers between a peripheral device and
+              *     memory are supported;
+              *  - minimal transfer chunk is 4 bytes and consequently
+              *     source and destination addresses must be 4-byte aligned
+              *     and transfer size must be aligned on (4 * maxburst)
+              *     boundary;
+              *  - during the transfer RAM address is being incremented by
+              *     the size of minimal transfer chunk;
+              *  - peripheral port's address is constant during the transfer.
+              */
+
+             cfg = (void *)arg;
+
+             if (cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES ||
+                 cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES ||

and why this limtation, doesnt seem covered above?

I created this limitation because FIFO registers of LPC and SDHC
support _only_ 4-byte access.

I tried to cover this limitation in the statement "minimal transfer chunk
is 4 bytes". Should I make it more explicit?

expose these as capablities and try to use these in your client driver. Already
we have audio drivers using those...

-- 
~Vinod