[PATCH v5 3/4] dmaengine: pl330: Store pointer to slave device

Krzysztof Kozlowski krzk at kernel.org
Tue Jan 17 09:29:42 PST 2017


On Tue, Jan 17, 2017 at 01:48:57PM +0100, Marek Szyprowski 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>
> Acked-by: Arnd Bergmann <arnd at arndb.de>

Any particular reason for removing my Reviewed-by? Any changes here?

Best regards,
Krzysztof

> ---
>  drivers/dma/pl330.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index b6b2cc912380..c77a3494659c 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 {
> @@ -2093,6 +2094,14 @@ 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;
> +	} 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
> 



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