From 4a89a24e26670921614a83098e5c0692de2be86e Mon Sep 17 00:00:00 2001 From: Masahiro Yamada <yamada.masahiro@socionext.com> Date: Thu, 25 Aug 2016 14:52:38 +0900 Subject: [PATCH] mmc: uniphier-sd: just return if already set to desired clock rate With this, we can save unnecessary udelay(). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- drivers/mmc/uniphier-sd.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/uniphier-sd.c b/drivers/mmc/uniphier-sd.c index 40a5c85e37..701b26f44c 100644 --- a/drivers/mmc/uniphier-sd.c +++ b/drivers/mmc/uniphier-sd.c @@ -571,6 +571,9 @@ static void uniphier_sd_set_clk_rate(struct uniphier_sd_priv *priv, val = UNIPHIER_SD_CLKCTL_DIV1024; tmp = readl(priv->regbase + UNIPHIER_SD_CLKCTL); + if (tmp & UNIPHIER_SD_CLKCTL_SCLKEN && + (tmp & UNIPHIER_SD_CLKCTL_DIV_MASK) == val) + return; /* stop the clock before changing its rate to avoid a glitch signal */ tmp &= ~UNIPHIER_SD_CLKCTL_SCLKEN; @@ -582,6 +585,8 @@ static void uniphier_sd_set_clk_rate(struct uniphier_sd_priv *priv, tmp |= UNIPHIER_SD_CLKCTL_SCLKEN; writel(tmp, priv->regbase + UNIPHIER_SD_CLKCTL); + + udelay(1000); } static int uniphier_sd_set_ios(struct udevice *dev) @@ -599,8 +604,6 @@ static int uniphier_sd_set_ios(struct udevice *dev) uniphier_sd_set_ddr_mode(priv, mmc); uniphier_sd_set_clk_rate(priv, mmc); - udelay(1000); - return 0; } -- 2.39.5