[PATCH v2 3/4] dmaengine: pl330: Store pointer to slave device

[Krzysztof Kozlowski]

On Mon, Jan 9, 2017 at 4:03 PM, Marek Szyprowski
<m.szyprowski at samsung.com> wrote:
> Store the pointer to slave device, which requested our channel. It will be
> later used to implement runtime PM of PL330 DMA controller. Although
> DMA channels might be requested many times, each DMA peripheral channel is
> physically dedicated only for specific hardware, so there should be only
> one slave device for each channel.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
> ---
>  drivers/dma/pl330.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 3c80e71271a2..9c72f535739c 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -450,6 +450,7 @@ struct dma_pl330_chan {
>
>         /* for runtime pm tracking */
>         bool active;
> +       struct device *slave;
>  };
>
>  struct pl330_dmac {
> @@ -2113,6 +2114,14 @@ static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,
>         if (chan_id >= pl330->num_peripherals)
>                 return NULL;
>
> +       if (!pl330->peripherals[chan_id].slave)
> +               pl330->peripherals[chan_id].slave = slave;

Following coding style, this should be inside {} because the other
branch has them. Beside that:
Reviewed-by: Krzysztof Kozlowski <krzk at kernel.org>

Best regards,
Krzysztof

> +       else if (pl330->peripherals[chan_id].slave != slave) {
> +               dev_err(pl330->ddma.dev,
> +                       "Can't use same channel with multiple slave devices!\n");
> +               return NULL;
> +       }
> +
>         return dma_get_slave_channel(&pl330->peripherals[chan_id].chan);
>  }
>
> --
> 1.9.1
>