[U-Boot] [PATCH 3/9] ARM: exynos: clock: modify the set_mmc_clk for exynos4

[U-Boot] [PATCH 3/9] ARM: exynos: clock: modify the set_mmc_clk for exynos4

[Jaehoon Chung]

Modified the mmc_set_clock for exynos4.
The goal of this patch is that fsys-div register should be reset.
And restore the div-value, not using the value of lowlevel_init.
(For using SDMMC4, this patch is needs)

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
 arch/arm/cpu/armv7/exynos/clock.c |   16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
index 2c2029a..5ebdda0 100644
--- a/arch/arm/cpu/armv7/exynos/clock.c
+++ b/arch/arm/cpu/armv7/exynos/clock.c
@@ -869,7 +869,7 @@ static void exynos4_set_mmc_clk(int dev_index, unsigned int div)
 {
 	struct exynos4_clock *clk =
 		(struct exynos4_clock *)samsung_get_base_clock();
-	unsigned int addr;
+	unsigned int addr, clear_bit, set_bit;
 
 	/*
 	 * CLK_DIV_FSYS1
@@ -877,20 +877,26 @@ static void exynos4_set_mmc_clk(int dev_index, unsigned int div)
 	 * CLK_DIV_FSYS2
 	 * MMC2_PRE_RATIO [15:8], MMC3_PRE_RATIO [31:24]
 	 * CLK_DIV_FSYS3
-	 * MMC4_PRE_RATIO [15:8]
+	 * MMC4_PRE_RATIO [15:8], MMC4_RATIO [3:0]
 	 */
 	if (dev_index < 2) {
 		addr = (unsigned int)&clk->div_fsys1;
-	}  else if (dev_index == 4) {
+		clear_bit = 0xff << ((dev_index << 4) + 8);
+		set_bit = (div & 0xff) << ((dev_index << 4) + 8);
+	} else if (dev_index == 4) {
 		addr = (unsigned int)&clk->div_fsys3;
 		dev_index -= 4;
+		/* Clear all bit, and restore the MMC4_PRE_RATIO value wit div */
+		clear_bit = 0xffff << dev_index;
+		set_bit = (div & 0xff) << (dev_index + 8);
 	} else {
 		addr = (unsigned int)&clk->div_fsys2;
 		dev_index -= 2;
+		clear_bit = 0xff << ((dev_index << 4) + 8);
+		set_bit = (div & 0xff) << ((dev_index << 4) + 8);
 	}
 
-	clrsetbits_le32(addr, 0xff << ((dev_index << 4) + 8),
-			(div & 0xff) << ((dev_index << 4) + 8));
+	clrsetbits_le32(addr, clear_bit, set_bit);
 }
 
 /* exynos5: set the mmc clock */
-- 
1.7.9.5