Re: [PATCH] dw_dmac: adjust slave_id accordingly to request line base

From: Viresh Kumar
Date: Tue Jan 29 2013 - 01:27:05 EST


Next time, please direct these mails to my Linaro id :)

On Mon, Jan 28, 2013 at 4:34 PM, Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> On some hardware configurations we have got the request line with the offset.
> The patch introduces convert_slave_id() helper for that cases. The request line
> base is got from the platform device resources provided by the IORESOURCE_DMA
> type.

@Vinod: Is IORESOURCE_DMA suitable for this purpose?

> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> drivers/dma/dw_dmac.c | 13 +++++++++++++
> drivers/dma/dw_dmac_regs.h | 1 +
> 2 files changed, 14 insertions(+)
>
> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> index 3155c11..8484ca1 100644
> --- a/drivers/dma/dw_dmac.c
> +++ b/drivers/dma/dw_dmac.c
> @@ -995,6 +995,13 @@ static inline void convert_burst(u32 *maxburst)
> *maxburst = 0;
> }
>
> +static inline void convert_slave_id(struct dw_dma_chan *dwc)
> +{
> + struct dw_dma *dw = to_dw_dma(dwc->chan.device);
> +
> + dwc->dma_sconfig.slave_id -= dw->request_line_base;
> +}
> +
> static int
> set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
> {
> @@ -1009,6 +1016,7 @@ set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
>
> convert_burst(&dwc->dma_sconfig.src_maxburst);
> convert_burst(&dwc->dma_sconfig.dst_maxburst);
> + convert_slave_id(dwc);
>
> return 0;
> }
> @@ -1717,6 +1725,11 @@ static int dw_probe(struct platform_device *pdev)
> memcpy(dw->data_width, pdata->data_width, 4);
> }
>
> + /* Get the base request line if set */
> + io = platform_get_resource(pdev, IORESOURCE_DMA, 0);
> + if (io)
> + dw->request_line_base = (unsigned int)io->start;
> +

How will it work in case of DT?

> /* Calculate all channel mask before DMA setup */
> dw->all_chan_mask = (1 << nr_channels) - 1;
>
> diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
> index 88dd8eb..3eeb766 100644
> --- a/drivers/dma/dw_dmac_regs.h
> +++ b/drivers/dma/dw_dmac_regs.h
> @@ -248,6 +248,7 @@ struct dw_dma {
> /* hardware configuration */
> unsigned char nr_masters;
> unsigned char data_width[4];
> + unsigned int request_line_base;
>
> struct dw_dma_chan chan[0];
> };

--
viresh
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