[PATCH v2 2/3] dmaengine: imx-sdma: Only check ratio on parts that support 1:1

[Angus Ainslie (Purism)]

On imx8mq B0 chip, AHB/SDMA clock ratio 2:1 can't be supported,
since SDMA clock ratio has to be increased to 250Mhz, AHB can't reach
to 500Mhz, so use 1:1 instead.

To limit this change to the imx8mq for now this patch also adds an
im8mq-sdma compatible string.

Signed-off-by: Angus Ainslie (Purism) <an...@akkea.ca>
---
 drivers/dma/imx-sdma.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 5f3c1378b90e..99d9f431ae2c 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -419,6 +419,7 @@ struct sdma_driver_data {
        int chnenbl0;
        int num_events;
        struct sdma_script_start_addrs  *script_addrs;
+       bool check_ratio;
 };
 
 struct sdma_engine {
@@ -557,6 +558,13 @@ static struct sdma_driver_data sdma_imx7d = {
        .script_addrs = &sdma_script_imx7d,
 };
 
+static struct sdma_driver_data sdma_imx8mq = {
+       .chnenbl0 = SDMA_CHNENBL0_IMX35,
+       .num_events = 48,
+       .script_addrs = &sdma_script_imx7d,
+       .check_ratio = 1,
+};
+
 static const struct platform_device_id sdma_devtypes[] = {
        {
                .name = "imx25-sdma",
@@ -579,6 +587,9 @@ static const struct platform_device_id sdma_devtypes[] = {
        }, {
                .name = "imx7d-sdma",
                .driver_data = (unsigned long)&sdma_imx7d,
+       }, {
+               .name = "imx8mq-sdma",
+               .driver_data = (unsigned long)&sdma_imx8mq,
        }, {
                /* sentinel */
        }
@@ -593,6 +604,7 @@ static const struct of_device_id sdma_dt_ids[] = {
        { .compatible = "fsl,imx31-sdma", .data = &sdma_imx31, },
        { .compatible = "fsl,imx25-sdma", .data = &sdma_imx25, },
        { .compatible = "fsl,imx7d-sdma", .data = &sdma_imx7d, },
+       { .compatible = "fsl,imx8mq-sdma", .data = &sdma_imx8mq, },
        { /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, sdma_dt_ids);
@@ -1852,7 +1864,8 @@ 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))
+       if (sdma->drvdata->check_ratio &&
+           (clk_get_rate(sdma->clk_ahb) == clk_get_rate(sdma->clk_ipg)))
                sdma->clk_ratio = 1;
 
        /* Be sure SDMA has not started yet */
-- 
2.17.1