diff options
| author | Angus Ainslie (Purism) <angus@akkea.ca> | 2019-01-28 09:03:21 -0700 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2019-02-25 23:25:42 +0530 |
| commit | 25aaa75df1e659901d77085bcdd25eaabf265688 (patch) | |
| tree | dfbc427cf2fa786c976bcd0b5edeebd3d39b15fd /drivers/dma | |
| parent | 3b6679f91e6f7772b7bfa3417b637f09e5998357 (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.c | 18 |
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); |