From 34b664a20e2664de0d0d7990ca60276b96c08c75 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Fri, 24 Jun 2011 13:57:56 +0100 Subject: mmc: dw_mmc: handle unaligned buffers and sizes Update functions for PIO pushing and pulling data to and from the FIFO so that they can handle unaligned output buffers and unaligned buffer lengths. This makes more of the tests in mmc_test pass. Unaligned lengths in pulls are handled by reading the full FIFO item, and storing the remaining bytes in a small internal buffer (part_buf). The next data pull will copy data out of this buffer first before accessing the FIFO again. Similarly, for pushes the final bytes that don't fill a FIFO item are stored in the part_buf (or sent anyway if it's the last transfer), and then the part_buf is included at the beginning of the next buffer pushed. Unaligned buffers in pulls are handled specially if the architecture cannot do efficient unaligned accesses, by reading FIFO items into a aligned local buffer, and memcpy'ing them into the output buffer, again storing any remaining bytes in the internal buffer. Similarly for pushes the buffer is memcpy'd into an aligned local buffer then written to the FIFO. Signed-off-by: James Hogan Acked-by: Will Newton Signed-off-by: Chris Ball --- include/linux/mmc/dw_mmc.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux/mmc') diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h index 01db1a0b3dd1..f3f68ee08a1e 100644 --- a/include/linux/mmc/dw_mmc.h +++ b/include/linux/mmc/dw_mmc.h @@ -76,6 +76,9 @@ struct mmc_data; * @slot: Slots sharing this MMC controller. * @fifo_depth: depth of FIFO. * @data_shift: log2 of FIFO item size. + * @part_buf_start: Start index in part_buf. + * @part_buf_count: Bytes of partial data in part_buf. + * @part_buf: Simple buffer for partial fifo reads/writes. * @push_data: Pointer to FIFO push function. * @pull_data: Pointer to FIFO pull function. * @quirks: Set of quirks that apply to specific versions of the IP. @@ -149,6 +152,13 @@ struct dw_mci { /* FIFO push and pull */ int fifo_depth; int data_shift; + u8 part_buf_start; + u8 part_buf_count; + union { + u16 part_buf16; + u32 part_buf32; + u64 part_buf; + }; void (*push_data)(struct dw_mci *host, void *buf, int cnt); void (*pull_data)(struct dw_mci *host, void *buf, int cnt); -- cgit v1.2.1