[PATCH v2 3/4] dmaengine: pl330: Store pointer to slave device
flat view
From: Krzysztof Kozlowski <krzk@kernel.org>
Date: 2017-01-09 18:08:21
Also in:
linux-pm, linux-samsung-soc
On Mon, Jan 9, 2017 at 4:03 PM, Marek Szyprowski [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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@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@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