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authorAngus Ainslie (Purism) <angus@akkea.ca>2019-01-28 09:03:21 -0700
committerVinod Koul <vkoul@kernel.org>2019-02-25 23:25:42 +0530
commit25aaa75df1e659901d77085bcdd25eaabf265688 (patch)
treedfbc427cf2fa786c976bcd0b5edeebd3d39b15fd /drivers/dma
parent3b6679f91e6f7772b7bfa3417b637f09e5998357 (diff)
dmaengine: imx-sdma: add clock ratio 1:1 check
On i.mx8 mscale B0 chip, AHB/SDMA clock ratio 2:1 can't be supportted, since SDMA clock ratio has to be increased to 250Mhz, AHB can't reach to 500Mhz, so use 1:1 instead. Based on NXP commit MLK-16841-1 by Robin Gong <yibin.gong@nxp.com> Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/imx-sdma.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index a2b0a0e71168..fc8bc80617d8 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -440,6 +440,8 @@ struct sdma_engine {
unsigned int irq;
dma_addr_t bd0_phys;
struct sdma_buffer_descriptor *bd0;
+ /* clock ratio for AHB:SDMA core. 1:1 is 1, 2:1 is 0*/
+ bool clk_ratio;
};
static int sdma_config_write(struct dma_chan *chan,
@@ -662,8 +664,11 @@ static int sdma_run_channel0(struct sdma_engine *sdma)
dev_err(sdma->dev, "Timeout waiting for CH0 ready\n");
/* Set bits of CONFIG register with dynamic context switching */
- if (readl(sdma->regs + SDMA_H_CONFIG) == 0)
- writel_relaxed(SDMA_H_CONFIG_CSM, sdma->regs + SDMA_H_CONFIG);
+ reg = readl(sdma->regs + SDMA_H_CONFIG);
+ if ((reg & SDMA_H_CONFIG_CSM) == 0) {
+ reg |= SDMA_H_CONFIG_CSM;
+ writel_relaxed(reg, sdma->regs + SDMA_H_CONFIG);
+ }
return ret;
}
@@ -1839,6 +1844,9 @@ static int sdma_init(struct sdma_engine *sdma)
if (ret)
goto disable_clk_ipg;
+ if (clk_get_rate(sdma->clk_ahb) == clk_get_rate(sdma->clk_ipg))
+ sdma->clk_ratio = 1;
+
/* Be sure SDMA has not started yet */
writel_relaxed(0, sdma->regs + SDMA_H_C0PTR);
@@ -1879,8 +1887,10 @@ static int sdma_init(struct sdma_engine *sdma)
writel_relaxed(0x4050, sdma->regs + SDMA_CHN0ADDR);
/* Set bits of CONFIG register but with static context switching */
- /* FIXME: Check whether to set ACR bit depending on clock ratios */
- writel_relaxed(0, sdma->regs + SDMA_H_CONFIG);
+ if (sdma->clk_ratio)
+ writel_relaxed(SDMA_H_CONFIG_ACR, sdma->regs + SDMA_H_CONFIG);
+ else
+ writel_relaxed(0, sdma->regs + SDMA_H_CONFIG);
writel_relaxed(ccb_phys, sdma->regs + SDMA_H_C0PTR);