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...@renesas.com>
---
drivers/dma/sh/rcar-dmac.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 204160e..bae0fe8 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1806,7 +1806,17 @@ static int rcar_dmac_parse_of(struct device *dev, struct
rcar_dmac *dmac)
return -EINVAL;
}
- dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0);
+ /*
+ * If the driver is unable to read dma-channel-mask property,
+ * the driver assumes that it can use all channels.
+ */
+ ret = of_property_read_u32(np, "dma-channel-mask",
+ &dmac->channels_mask);
+ if (ret < 0)
+ dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0);
+
+ /* 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
