This patch adds dma-channel-mask property support not to reserve
some DMA channels for some reasons. (for example: a heterogeneous
CPU uses it.)
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
drivers/dma/sh/rcar-dmac.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 542786d..f06016d 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -203,7 +203,7 @@ struct rcar_dmac {
unsigned int n_channels;
struct rcar_dmac_chan *channels;
- unsigned int channels_mask;
+ u32 channels_mask;
DECLARE_BITMAP(modules, 256);
};
@@ -1810,7 +1810,15 @@ static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac)
return -EINVAL;
}
+ /*
+ * If the driver is unable to read dma-channel-mask property,
+ * the driver assumes that it can use all channels.
+ */
dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0);
+ of_property_read_u32(np, "dma-channel-mask", &dmac->channels_mask);
+
+ /* If the property has out-of-channel mask, this driver clears it */
+ dmac->channels_mask &= GENMASK(dmac->n_channels - 1, 0);
return 0;
}
--
2.7.4
