exynos:clock: Add i2c clock

This patch adds i2c clock for Exynos4
Signed-off-by: NPiotr Wilczek <p.wilczek@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
CC: Minkyu Kang <mk7.kang@samsung.com>

arch/arm/cpu/armv7/exynos/clock.c

@@ -732,6 +732,21 @@ static unsigned long exynos5_get_i2c_clk(void)
 	return aclk_66;
 }
 
+static unsigned long exynos4_get_i2c_clk(void)
+{
+	struct exynos4_clock *clk =
+		(struct exynos4_clock *)samsung_get_base_clock();
+	unsigned long sclk, aclk_100;
+	unsigned int ratio;
+
+	sclk = get_pll_clk(APLL);
+
+	ratio = (readl(&clk->div_top)) >> 4;
+	ratio &= 0xf;
+	aclk_100 = sclk / (ratio + 1);
+	return aclk_100;
+}
+
 unsigned long get_pll_clk(int pllreg)
 {
 	if (cpu_is_exynos5())
@@ -752,6 +767,8 @@ unsigned long get_i2c_clk(void)
 {
 	if (cpu_is_exynos5()) {
 		return exynos5_get_i2c_clk();
+	} else if (cpu_is_exynos4()) {
+		return exynos4_get_i2c_clk();
 	} else {
 		debug("I2C clock is not set for this CPU\n");
 		return 0;