Re: [PATCH 2/4] dmaengine/dw_dmac: allow src/dst masters to beconfigured at runtime

[Dan Williams]

[ copying Haavard's new address ]

On Tue, Nov 23, 2010 at 3:06 AM, Jamie Iles <jamie@xxxxxxxxxxxxx> wrote:
> Some platforms have flexible mastering capabilities and this needs
> to be selected at runtime. If the platform has specified private
> data in the form of the dw_dma_slave then fetch the source and
> destination masters from here. If this isn't present, default to
> the previous of 0 and 1.
>
> Cc: Haavard Skinnemoen <haavard.skinnemoen@xxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Signed-off-by: Jamie Iles <jamie.iles@xxxxxxxxxxxx>
> ---
>  drivers/dma/dw_dmac.c   |   31 +++++++++++++++++--------------
>  include/linux/dw_dmac.h |    2 ++
>  2 files changed, 19 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> index 08c51d4..64024f1 100644
> --- a/drivers/dma/dw_dmac.c
> +++ b/drivers/dma/dw_dmac.c
> @@ -32,15 +32,18 @@
>  * which does not support descriptor writeback.
>  */
>
> -/* NOTE:  DMS+SMS is system-specific. We should get this information
> - * from the platform code somehow.
> - */
> -#define DWC_DEFAULT_CTLLO      (DWC_CTLL_DST_MSIZE(0)          \
> -                               | DWC_CTLL_SRC_MSIZE(0)         \
> -                               | DWC_CTLL_DMS(0)               \
> -                               | DWC_CTLL_SMS(1)               \
> -                               | DWC_CTLL_LLP_D_EN             \
> -                               | DWC_CTLL_LLP_S_EN)
> +#define DWC_DEFAULT_CTLLO(private) ({                           \
> +                struct dw_dma_slave *__slave = (private);       \
> +                int dms = __slave ? __slave->dst_master : 0;    \
> +                int sms = __slave ? __slave->src_master : 1;    \
> +                                                                \
> +                (DWC_CTLL_DST_MSIZE(0)                         \
> +                 | DWC_CTLL_SRC_MSIZE(0)                       \
> +                 | DWC_CTLL_LLP_D_EN                           \
> +                 | DWC_CTLL_LLP_S_EN                            \
> +                 | DWC_CTLL_DMS(dms)                           \
> +                 | DWC_CTLL_SMS(sms));                         \
> +        })
>
>  /*
>  * This is configuration-dependent and usually a funny size like 4095.
> @@ -591,7 +594,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
>        else
>                src_width = dst_width = 0;
>
> -       ctllo = DWC_DEFAULT_CTLLO
> +       ctllo = DWC_DEFAULT_CTLLO(chan->private)
>                        | DWC_CTLL_DST_WIDTH(dst_width)
>                        | DWC_CTLL_SRC_WIDTH(src_width)
>                        | DWC_CTLL_DST_INC
> @@ -672,7 +675,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
>
>        switch (direction) {
>        case DMA_TO_DEVICE:
> -               ctllo = (DWC_DEFAULT_CTLLO
> +               ctllo = (DWC_DEFAULT_CTLLO(chan->private)
>                                | DWC_CTLL_DST_WIDTH(reg_width)
>                                | DWC_CTLL_DST_FIX
>                                | DWC_CTLL_SRC_INC
> @@ -717,7 +720,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
>                }
>                break;
>        case DMA_FROM_DEVICE:
> -               ctllo = (DWC_DEFAULT_CTLLO
> +               ctllo = (DWC_DEFAULT_CTLLO(chan->private)
>                                | DWC_CTLL_SRC_WIDTH(reg_width)
>                                | DWC_CTLL_DST_INC
>                                | DWC_CTLL_SRC_FIX
> @@ -1129,7 +1132,7 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
>                case DMA_TO_DEVICE:
>                        desc->lli.dar = dws->tx_reg;
>                        desc->lli.sar = buf_addr + (period_len * i);
> -                       desc->lli.ctllo = (DWC_DEFAULT_CTLLO
> +                       desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
>                                        | DWC_CTLL_DST_WIDTH(reg_width)
>                                        | DWC_CTLL_SRC_WIDTH(reg_width)
>                                        | DWC_CTLL_DST_FIX
> @@ -1140,7 +1143,7 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
>                case DMA_FROM_DEVICE:
>                        desc->lli.dar = buf_addr + (period_len * i);
>                        desc->lli.sar = dws->rx_reg;
> -                       desc->lli.ctllo = (DWC_DEFAULT_CTLLO
> +                       desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
>                                        | DWC_CTLL_SRC_WIDTH(reg_width)
>                                        | DWC_CTLL_DST_WIDTH(reg_width)
>                                        | DWC_CTLL_DST_INC
> diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h
> index c8aad71..8014eb8 100644
> --- a/include/linux/dw_dmac.h
> +++ b/include/linux/dw_dmac.h
> @@ -52,6 +52,8 @@ struct dw_dma_slave {
>        enum dw_dma_slave_width reg_width;
>        u32                     cfg_hi;
>        u32                     cfg_lo;
> +       int                     src_master;
> +       int                     dst_master;
>  };
>
>  /* Platform-configurable bits in CFG_HI */
> --
> 1.7.2.3
>
> --
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