From patchwork Thu Feb 27 11:27:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jerome Brunet X-Patchwork-Id: 236943 List-Id: U-Boot discussion From: jbrunet at baylibre.com (Jerome Brunet) Date: Thu, 27 Feb 2020 12:27:35 +0100 Subject: [PATCH v2 3/6] clk: meson: reset mmc clock on probe In-Reply-To: <20200227112738.494579-1-jbrunet@baylibre.com> References: <20200227112738.494579-1-jbrunet@baylibre.com> Message-ID: <20200227112738.494579-4-jbrunet@baylibre.com> 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 Tested-by: Anand Moon Signed-off-by: Jerome Brunet --- 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 32cbf752aed8..0ba6c303e122 100644 --- a/drivers/clk/meson/axg.c +++ b/drivers/clk/meson/axg.c @@ -290,6 +290,13 @@ 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 1b2523bbf1fe..03d885d986b8 100644 --- a/drivers/clk/meson/g12a.c +++ b/drivers/clk/meson/g12a.c @@ -976,6 +976,13 @@ 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 abb5337e7829..aedba991603f 100644 --- a/drivers/clk/meson/gxbb.c +++ b/drivers/clk/meson/gxbb.c @@ -886,6 +886,13 @@ 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;