[U-Boot] [PATCH v2] arm: exynos: fix clock calculation

Minkyu Kang mk7.kang at samsung.com
Tue Jul 9 09:37:22 CEST 2013


There are differnce with clock calcuation by cpu variations.
This patch will fix it according to user manual.

Signed-off-by: Minkyu Kang <mk7.kang at samsung.com>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com>
---
Changes for v2:
 - remove hard-coded constants. 

 arch/arm/cpu/armv7/exynos/clock.c |   43 ++++++++++++++++++++++++++++++++-----
 1 file changed, 38 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/armv7/exynos/clock.c b/arch/arm/cpu/armv7/exynos/clock.c
index e1c4246..9f07181 100644
--- a/arch/arm/cpu/armv7/exynos/clock.c
+++ b/arch/arm/cpu/armv7/exynos/clock.c
@@ -27,6 +27,10 @@
 #include <asm/arch/clk.h>
 #include <asm/arch/periph.h>
 
+#define PLL_DIV_1024	1024
+#define PLL_DIV_65535	65535
+#define PLL_DIV_65536	65536
+
 /* *
  * This structure is to store the src bit, div bit and prediv bit
  * positions of the peripheral clocks of the src and div registers
@@ -85,6 +89,7 @@ static struct set_epll_con_val exynos5_epll_div[] = {
 static int exynos_get_pll_clk(int pllreg, unsigned int r, unsigned int k)
 {
 	unsigned long m, p, s = 0, mask, fout;
+	unsigned int div;
 	unsigned int freq;
 	/*
 	 * APLL_CON: MIDV [25:16]
@@ -110,14 +115,42 @@ static int exynos_get_pll_clk(int pllreg, unsigned int r, unsigned int k)
 	if (pllreg == EPLL) {
 		k = k & 0xffff;
 		/* FOUT = (MDIV + K / 65536) * FIN / (PDIV * 2^SDIV) */
-		fout = (m + k / 65536) * (freq / (p * (1 << s)));
+		fout = (m + k / PLL_DIV_65536) * (freq / (p * (1 << s)));
 	} else if (pllreg == VPLL) {
 		k = k & 0xfff;
-		/* FOUT = (MDIV + K / 1024) * FIN / (PDIV * 2^SDIV) */
-		fout = (m + k / 1024) * (freq / (p * (1 << s)));
+
+		/*
+		 * Exynos4210
+		 * FOUT = (MDIV + K / 1024) * FIN / (PDIV * 2^SDIV)
+		 *
+		 * Exynos4412
+		 * FOUT = (MDIV + K / 65535) * FIN / (PDIV * 2^SDIV)
+		 *
+		 * Exynos5250
+		 * FOUT = (MDIV + K / 65536) * FIN / (PDIV * 2^SDIV)
+		 */
+		if (proid_is_exynos4210())
+			div = PLL_DIV_1024;
+		else if (proid_is_exynos4412())
+			div = PLL_DIV_65535;
+		else if (proid_is_exynos5250())
+			div = PLL_DIV_65536;
+		else
+			return 0;
+
+		fout = (m + k / div) * (freq / (p * (1 << s)));
 	} else {
-		/* FOUT = MDIV * FIN / (PDIV * 2^SDIV) */
-		fout = m * (freq / (p * (1 << s)));
+		/*
+		 * Exynos4210
+		 * FOUT = MDIV * FIN / (PDIV * 2^SDIV)
+		 *
+		 * Exynos4412 / Exynos5250
+		 * FOUT = MDIV * FIN / (PDIV * 2^(SDIV-1))
+		 */
+		if (proid_is_exynos4210())
+			fout = m * (freq / (p * (1 << s)));
+		else
+			fout = m * (freq / (p * (1 << (s - 1))));
 	}
 
 	return fout;
-- 
1.7.9.5


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