[U-Boot] [PATCH v2 1/3] sunxi: sun4i: improve cpu clock selection method

[Iain Paton]

clock_set_pll1 would pick the next highest available cpu clock speed if
a value not in the pre defined table was selected. this potentially
results in overclocking the soc.

reverse the selection method so that we select the next lowest speed
and add the missing 912Mhz setting that's requested by sun7i which also
uses the sun4i clock code.

Signed-off-by: Iain Paton <ipaton0 at gmail.com>
---
 arch/arm/cpu/armv7/sunxi/clock_sun4i.c | 35 ++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/arch/arm/cpu/armv7/sunxi/clock_sun4i.c b/arch/arm/cpu/armv7/sunxi/clock_sun4i.c
index 49f4032..c3e04af 100644
--- a/arch/arm/cpu/armv7/sunxi/clock_sun4i.c
+++ b/arch/arm/cpu/armv7/sunxi/clock_sun4i.c
@@ -100,22 +100,23 @@ static struct {
 	unsigned int freq;
 } pll1_para[] = {
 	/* This array must be ordered by frequency. */
-	{ PLL1_CFG(16, 0, 0, 0), 384000000 },
-	{ PLL1_CFG(16, 1, 0, 0), 768000000 },
-	{ PLL1_CFG(20, 1, 0, 0), 960000000 },
-	{ PLL1_CFG(21, 1, 0, 0), 1008000000},
-	{ PLL1_CFG(22, 1, 0, 0), 1056000000},
-	{ PLL1_CFG(23, 1, 0, 0), 1104000000},
-	{ PLL1_CFG(24, 1, 0, 0), 1152000000},
-	{ PLL1_CFG(25, 1, 0, 0), 1200000000},
-	{ PLL1_CFG(26, 1, 0, 0), 1248000000},
-	{ PLL1_CFG(27, 1, 0, 0), 1296000000},
-	{ PLL1_CFG(28, 1, 0, 0), 1344000000},
-	{ PLL1_CFG(29, 1, 0, 0), 1392000000},
-	{ PLL1_CFG(30, 1, 0, 0), 1440000000},
 	{ PLL1_CFG(31, 1, 0, 0), 1488000000},
-	/* Final catchall entry */
-	{ PLL1_CFG(31, 1, 0, 0), ~0},
+	{ PLL1_CFG(30, 1, 0, 0), 1440000000},
+	{ PLL1_CFG(29, 1, 0, 0), 1392000000},
+	{ PLL1_CFG(28, 1, 0, 0), 1344000000},
+	{ PLL1_CFG(27, 1, 0, 0), 1296000000},
+	{ PLL1_CFG(26, 1, 0, 0), 1248000000},
+	{ PLL1_CFG(25, 1, 0, 0), 1200000000},
+	{ PLL1_CFG(24, 1, 0, 0), 1152000000},
+	{ PLL1_CFG(23, 1, 0, 0), 1104000000},
+	{ PLL1_CFG(22, 1, 0, 0), 1056000000},
+	{ PLL1_CFG(21, 1, 0, 0), 1008000000},
+	{ PLL1_CFG(20, 1, 0, 0), 960000000 },
+	{ PLL1_CFG(19, 1, 0, 0), 912000000 },
+	{ PLL1_CFG(16, 1, 0, 0), 768000000 },
+	/* Final catchall entry 384MHz*/
+	{ PLL1_CFG(16, 0, 0, 0), 0 },
+
 };
 
 void clock_set_pll1(unsigned int hz)
@@ -126,10 +127,12 @@ void clock_set_pll1(unsigned int hz)
 		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
 
 	/* Find target frequency */
-	while (pll1_para[i].freq < hz)
+	while (pll1_para[i].freq > hz)
 		i++;
 
 	hz = pll1_para[i].freq;
+	if (! hz)
+		hz = 384000000;
 
 	/* Calculate system clock divisors */
 	axi = DIV_ROUND_UP(hz, 432000000);	/* Max 450MHz */
-- 
2.1.3