From 6bcd67be8e3257d7f6e882359689dd48ae681cdd Mon Sep 17 00:00:00 2001
From: Robin Gong <yibin.gong@nxp.com>
Date: Thu, 16 Nov 2017 17:23:40 +0800
Subject: [PATCH] MLK-16841-1: dma: imx-sdma: add clock ration 1:1 check
On i.mx8 mscale B0 chip, AHB/SDMA clock ratio 2:1 can't be supportted,
since SDMA clock ration has to be increased to 250Mhz, AHB can't reach
to 500Mhz, so use 1:1 instead.
TODO: checkpatch warnings
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
Signed-off-by: Srikanth Krishnakar <Srikanth_Krishnakar@mentor.com>
---
Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt | 1 +
drivers/dma/imx-sdma.c | 9 ++++++++-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
index 0839b70f0261d3..81b8cad86d1705 100644
--- a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
+++ b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
@@ -69,6 +69,7 @@ Optional properties:
reg is the GPR register offset.
shift is the bit position inside the GPR register.
val is the value of the bit (0 or 1).
+- fsl,ratio-1-1: AHB/SDMA core clock ration 1:1, 2:1 without this.
Examples:
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 97bb4630b9c983..ebfc585db4ca4c 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -462,6 +462,8 @@ struct sdma_engine {
struct sdma_buffer_descriptor *bd0;
bool suspend_off;
int idx;
+ /* clock ration for AHB:SDMA core. 1:1 is 1, 2:1 is 0*/
+ bool clk_ratio;
};
static struct sdma_driver_data sdma_imx31 = {
@@ -2175,7 +2177,10 @@ static int sdma_init(struct sdma_engine *sdma)
/* 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);
@@ -2268,6 +2273,8 @@ static int sdma_probe(struct platform_device *pdev)
if (!sdma)
return -ENOMEM;
+ sdma->clk_ratio = of_property_read_bool(np, "fsl,ratio-1-1");
+
spin_lock_init(&sdma->channel_0_lock);
sdma->dev = &pdev->dev;
--
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