DMA: shdma: support the new CHCLR register layout
On newer r-car SoCs the CHCLR register only contains one bit per channel,
to which a 1 has to be written to reset the channel. Older SoC versions had
one CHCLR register per channel, to which a 0 must be written to reset the
channel and clear its buffers. This patch adds support for the newer
layout.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
index 9ee1272..53bd630 100644
--- a/drivers/dma/sh/shdma.c
+++ b/drivers/dma/sh/shdma.c
@@ -49,12 +49,22 @@
static DEFINE_SPINLOCK(sh_dmae_lock);
static LIST_HEAD(sh_dmae_devices);
+/*
+ * Different DMAC implementations provide different ways to clear DMA channels:
+ * (1) none - no CHCLR registers are available
+ * (2) one CHCLR register per channel - 0 has to be written to it to clear
+ * channel buffers
+ * (3) one CHCLR per several channels - 1 has to be written to the bit,
+ * corresponding to the specific channel to reset it
+ */
static void channel_clear(struct sh_dmae_chan *sh_dc)
{
struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
+ const struct sh_dmae_channel *chan_pdata = shdev->pdata->channel +
+ sh_dc->shdma_chan.id;
+ u32 val = shdev->pdata->chclr_bitwise ? 1 << chan_pdata->chclr_bit : 0;
- __raw_writel(0, shdev->chan_reg +
- shdev->pdata->channel[sh_dc->shdma_chan.id].chclr_offset);
+ __raw_writel(val, shdev->chan_reg + chan_pdata->chclr_offset);
}
static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)