[U-Boot] [PATCH] Exynos: clock: support get_mmc_clk for exynos

[Jaehoon Chung <jh80.chung@samsung.com>]

To get exactly clock value for mmc, support the get_mmc_clk() like
set_mmc_clk().

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 arch/arm/cpu/armv7/exynos/clock.c      |  107 ++++++++++++++++++++++++++++++++
 arch/arm/include/asm/arch-exynos/clk.h |    1 +
 2 files changed, 108 insertions(+), 0 deletions(-)

diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
index fe61f88..731bbff 100644
--- a/arch/arm/cpu/armv7/exynos/clock.c
+++ b/arch/arm/cpu/armv7/exynos/clock.c
@@ -373,6 +373,100 @@ static unsigned long exynos5_get_uart_clk(int dev_index)
 	return uclk;
 }
 
+static unsigned long exynos4_get_mmc_clk(int dev_index)
+{
+	struct exynos4_clock *clk =
+		(struct exynos4_clock *)samsung_get_base_clock();
+	unsigned long uclk, sclk;
+	unsigned int sel, ratio, pre_ratio;
+	int shift;
+
+	sel = readl(&clk->src_fsys);
+	sel = (sel >> (dev_index << 2)) & 0xf;
+
+	if (sel == 0x6)
+		sclk = get_pll_clk(MPLL);
+	else if (sel == 0x7)
+		sclk = get_pll_clk(EPLL);
+	else if (sel == 0x8)
+		sclk = get_pll_clk(VPLL);
+	else
+		return 0;
+
+	switch (dev_index) {
+	case 0:
+	case 1:
+		ratio = readl(&clk->div_fsys1);
+		pre_ratio = readl(&clk->div_fsys1);
+		break;
+	case 2:
+	case 3:
+		ratio = readl(&clk->div_fsys2);
+		pre_ratio = readl(&clk->div_fsys2);
+		break;
+	case 4:
+		ratio = readl(&clk->div_fsys3);
+		pre_ratio = readl(&clk->div_fsys3);
+		break;
+	default:
+		return 0;
+	}
+
+	if (dev_index == 1 || dev_index == 3)
+		shift = 16;
+
+	ratio = (ratio >> shift) & 0xf;
+	pre_ratio = (pre_ratio >> (shift + 8)) & 0xff;
+	uclk = (sclk / (ratio + 1)) / (pre_ratio + 1);
+
+	return uclk;
+}
+
+static unsigned long exynos5_get_mmc_clk(int dev_index)
+{
+	struct exynos5_clock *clk =
+		(struct exynos5_clock *)samsung_get_base_clock();
+	unsigned long uclk, sclk;
+	unsigned int sel, ratio, pre_ratio;
+	int shift;
+
+	sel = readl(&clk->src_fsys);
+	sel = (sel >> (dev_index << 2)) & 0xf;
+
+	if (sel == 0x6)
+		sclk = get_pll_clk(MPLL);
+	else if (sel == 0x7)
+		sclk = get_pll_clk(EPLL);
+	else if (sel == 0x8)
+		sclk = get_pll_clk(VPLL);
+	else
+		return 0;
+
+	switch (dev_index) {
+	case 0:
+	case 1:
+		ratio = readl(&clk->div_fsys1);
+		pre_ratio = readl(&clk->div_fsys1);
+		break;
+	case 2:
+	case 3:
+		ratio = readl(&clk->div_fsys2);
+		pre_ratio = readl(&clk->div_fsys2);
+		break;
+	default:
+		return 0;
+	}
+
+	if (dev_index == 1 || dev_index == 3)
+		shift = 16;
+
+	ratio = (ratio >> shift) & 0xf;
+	pre_ratio = (pre_ratio >> (shift + 8)) & 0xff;
+	uclk = (sclk / (ratio + 1)) / (pre_ratio + 1);
+
+	return uclk;
+}
+
 /* exynos4: set the mmc clock */
 static void exynos4_set_mmc_clk(int dev_index, unsigned int div)
 {
@@ -386,9 +480,14 @@ static void exynos4_set_mmc_clk(int dev_index, unsigned int div)
 	 * MMC0_PRE_RATIO [15:8], MMC1_PRE_RATIO [31:24]
 	 * CLK_DIV_FSYS2
 	 * MMC2_PRE_RATIO [15:8], MMC3_PRE_RATIO [31:24]
+	 * CLK_DIV_FSYS3
+	 * MMC4_PRE_RATIO [15:8]
 	 */
 	if (dev_index < 2) {
 		addr = (unsigned int)&clk->div_fsys1;
+	}  else if (dev_index == 4) {
+		addr = (unsigned int)&clk->div_fsys3;
+		dev_index -= 4;
 	} else {
 		addr = (unsigned int)&clk->div_fsys2;
 		dev_index -= 2;
@@ -963,6 +1062,14 @@ unsigned long get_uart_clk(int dev_index)
 		return exynos4_get_uart_clk(dev_index);
 }
 
+unsigned long get_mmc_clk(int dev_index)
+{
+	if (cpu_is_exynos5())
+		return exynos5_get_mmc_clk(dev_index);
+	else
+		return exynos4_get_mmc_clk(dev_index);
+}
+
 void set_mmc_clk(int dev_index, unsigned int div)
 {
 	if (cpu_is_exynos5())
diff --git a/arch/arm/include/asm/arch-exynos/clk.h b/arch/arm/include/asm/arch-exynos/clk.h
index cd12323..ff155d8 100644
--- a/arch/arm/include/asm/arch-exynos/clk.h
+++ b/arch/arm/include/asm/arch-exynos/clk.h
@@ -34,6 +34,7 @@ unsigned long get_arm_clk(void);
 unsigned long get_i2c_clk(void);
 unsigned long get_pwm_clk(void);
 unsigned long get_uart_clk(int dev_index);
+unsigned long get_mmc_clk(int deV_index);
 void set_mmc_clk(int dev_index, unsigned int div);
 unsigned long get_lcd_clk(void);
 void set_lcd_clk(void);
-- 
1.7.4.1