From fcf8adb787073ba6c673c1bb9900a059c7f6676f Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda Date: Mon, 9 Sep 2019 15:34:52 +0900 Subject: dmaengine: rcar-dmac: Add dma-channel-mask property support 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 Reviewed-by: Simon Horman Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/1568010892-17606-5-git-send-email-yoshihiro.shimoda.uh@renesas.com Signed-off-by: Vinod Koul --- 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 542786de69a9..f06016d38a05 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; } -- cgit v1.2.3