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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 <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/1568010892-17606-5-git-send-email-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Yoshihiro Shimoda 2019-09-09 15:34:52 +09:00 committed by Vinod Koul
parent d832c481bf
commit fcf8adb787
1 changed files with 9 additions and 1 deletions
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10
drivers/dma/sh/rcar-dmac.c
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@ -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;
}