mx6: soc: Clear the LDO ramp values up prior to setting the LDO voltages

Since ROM may modify the LDO ramp up time according to fuse setting,
it is safer to reset the ramp up field to its default value of 00:

00: 64 cycles of 24MHz clock;
01: 128 cycles of 24MHz clock;
02: 256 cycles of 24MHz clock;
03: 512 cycles of 24MHz clock;

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Jason Liu <r64343@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
index 2eee6e9a2db2a7c1730b01cc731ae5b6f55fba65..486b870312c179c789cfac42a0fb9db3bf5804e5 100644 (file)
--- a/arch/arm/cpu/armv7/mx6/soc.c
+++ b/arch/arm/cpu/armv7/mx6/soc.c
@@ -93,6 +93,20 @@ void init_aips(void)
        writel(0x00000000, &aips2->opacr4);
 }
 
+static void clear_ldo_ramp(void)
+{
+       struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
+       int reg;
+
+       /* ROM may modify LDO ramp up time according to fuse setting, so in
+        * order to be in the safe side we neeed to reset these settings to
+        * match the reset value: 0'b00
+        */
+       reg = readl(&anatop->ana_misc2);
+       reg &= ~(0x3f << 24);
+       writel(reg, &anatop->ana_misc2);
+}
+
 /*
  * Set the VDDSOC
  *
@@ -113,6 +127,8 @@ static void set_vddsoc(u32 mv)
        else
                val = (mv - 700) / 25;
 
+       clear_ldo_ramp();
+
        /*
         * Mask out the REG_CORE[22:18] bits (REG2_TRIG)
         * and set them to the calculated value (0.7V + val * 0.25V)