clk: meson: reset mmc clock on probe

On some SoCs, depending on the boot device, the MMC clock block may be
left in a weird state by the ROM code, in which no decent clock may be
provided. Reset the related register to make sure a sane MMC clock is
ready for the controller.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

diff --git a/drivers/clk/meson/axg.c b/drivers/clk/meson/axg.c
index 7035b59..4b0028d 100644 (file)
--- a/drivers/clk/meson/axg.c
+++ b/drivers/clk/meson/axg.c
@@ -291,6 +291,13 @@ static int meson_clk_probe(struct udevice *dev)
        if (IS_ERR(priv->map))
                return PTR_ERR(priv->map);
 
+       /*
+        * Depending on the boot src, the state of the MMC clock might
+        * be different. Reset it to make sure we won't get stuck
+        */
+       regmap_write(priv->map, HHI_NAND_CLK_CNTL, 0);
+       regmap_write(priv->map, HHI_SD_EMMC_CLK_CNTL, 0);
+
        debug("meson-clk-axg: probed\n");
 
        return 0;

diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c
index cada80e..c1976aa 100644 (file)
--- a/drivers/clk/meson/g12a.c
+++ b/drivers/clk/meson/g12a.c
@@ -978,6 +978,13 @@ static int meson_clk_probe(struct udevice *dev)
        if (IS_ERR(priv->map))
                return PTR_ERR(priv->map);
 
+       /*
+        * Depending on the boot src, the state of the MMC clock might
+        * be different. Reset it to make sure we won't get stuck
+        */
+       regmap_write(priv->map, HHI_NAND_CLK_CNTL, 0);
+       regmap_write(priv->map, HHI_SD_EMMC_CLK_CNTL, 0);
+
        debug("meson-clk-g12a: probed\n");
 
        return 0;

diff --git a/drivers/clk/meson/gxbb.c b/drivers/clk/meson/gxbb.c
index e781e08..5ef4dd7 100644 (file)
--- a/drivers/clk/meson/gxbb.c
+++ b/drivers/clk/meson/gxbb.c
@@ -887,6 +887,13 @@ static int meson_clk_probe(struct udevice *dev)
        if (IS_ERR(priv->map))
                return PTR_ERR(priv->map);
 
+       /*
+        * Depending on the boot src, the state of the MMC clock might
+        * be different. Reset it to make sure we won't get stuck
+        */
+       regmap_write(priv->map, HHI_NAND_CLK_CNTL, 0);
+       regmap_write(priv->map, HHI_SD_EMMC_CLK_CNTL, 0);
+
        debug("meson-clk: probed\n");
 
        return 0;