Commit f0816a36 authored by Maxime Ripard's avatar Maxime Ripard Committed by Vinod Koul
Browse files

dmaengine: xdmac: Add function to align width 



The code has some logic to compute the burst width according to the alignment
of the address we're using.

Move that in a function of its own to reduce code duplication.

Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: default avatarLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent ee0fe35c

drivers/dma/at_xdmac.c

+32 −31
Original line number Diff line number Diff line
@@ -749,6 +749,35 @@ at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, 
	return &first->tx_dma_desc;

}



static inline u32 at_xdmac_align_width(struct dma_chan *chan, dma_addr_t addr)

{

	u32 width;



	/*

	 * Check address alignment to select the greater data width we

	 * can use.

	 *

	 * Some XDMAC implementations don't provide dword transfer, in

	 * this case selecting dword has the same behavior as

	 * selecting word transfers.

	 */

	if (!(addr & 7)) {

		width = AT_XDMAC_CC_DWIDTH_DWORD;

		dev_dbg(chan2dev(chan), "%s: dwidth: double word\n", __func__);

	} else if (!(addr & 3)) {

		width = AT_XDMAC_CC_DWIDTH_WORD;

		dev_dbg(chan2dev(chan), "%s: dwidth: word\n", __func__);

	} else if (!(addr & 1)) {

		width = AT_XDMAC_CC_DWIDTH_HALFWORD;

		dev_dbg(chan2dev(chan), "%s: dwidth: half word\n", __func__);

	} else {

		width = AT_XDMAC_CC_DWIDTH_BYTE;

		dev_dbg(chan2dev(chan), "%s: dwidth: byte\n", __func__);

	}



	return width;

}



static struct dma_async_tx_descriptor *

at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,

			 size_t len, unsigned long flags)
@@ -779,24 +808,7 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 
	if (unlikely(!len))

		return NULL;



	/*

	 * Check address alignment to select the greater data width we can use.

	 * Some XDMAC implementations don't provide dword transfer, in this

	 * case selecting dword has the same behavior as selecting word transfers.

	 */

	if (!((src_addr | dst_addr) & 7)) {

		dwidth = AT_XDMAC_CC_DWIDTH_DWORD;

		dev_dbg(chan2dev(chan), "%s: dwidth: double word\n", __func__);

	} else if (!((src_addr | dst_addr)  & 3)) {

		dwidth = AT_XDMAC_CC_DWIDTH_WORD;

		dev_dbg(chan2dev(chan), "%s: dwidth: word\n", __func__);

	} else if (!((src_addr | dst_addr) & 1)) {

		dwidth = AT_XDMAC_CC_DWIDTH_HALFWORD;

		dev_dbg(chan2dev(chan), "%s: dwidth: half word\n", __func__);

	} else {

		dwidth = AT_XDMAC_CC_DWIDTH_BYTE;

		dev_dbg(chan2dev(chan), "%s: dwidth: byte\n", __func__);

	}

	dwidth = at_xdmac_align_width(chan, src_addr | dst_addr);



	/* Prepare descriptors. */

	while (remaining_size) {
@@ -826,19 +838,8 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 
		dev_dbg(chan2dev(chan), "%s: xfer_size=%zu\n", __func__, xfer_size);



		/* Check remaining length and change data width if needed. */

		if (!((src_addr | dst_addr | xfer_size) & 7)) {

			dwidth = AT_XDMAC_CC_DWIDTH_DWORD;

			dev_dbg(chan2dev(chan), "%s: dwidth: double word\n", __func__);

		} else if (!((src_addr | dst_addr | xfer_size)  & 3)) {

			dwidth = AT_XDMAC_CC_DWIDTH_WORD;

			dev_dbg(chan2dev(chan), "%s: dwidth: word\n", __func__);

		} else if (!((src_addr | dst_addr | xfer_size) & 1)) {

			dwidth = AT_XDMAC_CC_DWIDTH_HALFWORD;

			dev_dbg(chan2dev(chan), "%s: dwidth: half word\n", __func__);

		} else if ((src_addr | dst_addr | xfer_size) & 1) {

			dwidth = AT_XDMAC_CC_DWIDTH_BYTE;

			dev_dbg(chan2dev(chan), "%s: dwidth: byte\n", __func__);

		}

		dwidth = at_xdmac_align_width(chan,

					      src_addr | dst_addr | xfer_size);

		chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth);



		ublen = xfer_size >> dwidth;