On Tue, Apr 28, 2015 at 11:03:21AM +0200, Maxime Ripard wrote:
> 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: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
> ---
> drivers/dma/at_xdmac.c | 63 +++++++++++++++++++++++++-------------------------
> 1 file changed, 32 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> index 2d039512ecb3..cbeadeeed9c0 100644
> --- a/drivers/dma/at_xdmac.c
> +++ b/drivers/dma/at_xdmac.c
> @@ -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;
> --
> 2.3.6
>
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