[PATCH v3 3/6] clk: meson: reset mmc clock on probe

[Jerome Brunet]

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 at baylibre.com>
Tested-by: Anand Moon <linux.amoon at gmail.com>
Signed-off-by: Jerome Brunet <jbrunet at baylibre.com>
---
 drivers/clk/meson/axg.c  | 7 +++++++
 drivers/clk/meson/g12a.c | 7 +++++++
 drivers/clk/meson/gxbb.c | 7 +++++++
 3 files changed, 21 insertions(+)

diff --git a/drivers/clk/meson/axg.c b/drivers/clk/meson/axg.c
index 7035b59a1379..4b0028d04bf6 100644
--- 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 686d94ebfe85..9e6beca94ac3 100644
--- a/drivers/clk/meson/g12a.c
+++ b/drivers/clk/meson/g12a.c
@@ -977,6 +977,13 @@ 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 e781e08d9d5d..5ef4dd794d52 100644
--- 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;
-- 
2.24.1