From: Fabio Estevam fabio.estevam@freescale.com
When changing LDO voltages we need to wait for the required amount of time for the voltage to settle.
Also, as the timer is still not available when arch_cpu_init() is called, we need to call it later at board_postclk_init() phase.
Signed-off-by: Fabio Estevam fabio.estevam@freescale.com --- arch/arm/cpu/armv7/mx6/soc.c | 22 +++++++++++++++++++--- include/configs/mx6_common.h | 1 + 2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c index ee888ce..3aa3bb0 100644 --- a/arch/arm/cpu/armv7/mx6/soc.c +++ b/arch/arm/cpu/armv7/mx6/soc.c @@ -124,7 +124,7 @@ static void clear_ldo_ramp(void) static int set_ldo_voltage(enum ldo_reg ldo, u32 mv) { struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR; - u32 val, reg = readl(&anatop->reg_core); + u32 val, step, old, reg = readl(&anatop->reg_core); u8 shift;
if (mv < 725) @@ -150,9 +150,20 @@ static int set_ldo_voltage(enum ldo_reg ldo, u32 mv) return -EINVAL; }
+ old = (reg & (0x1F << shift)) >> shift; + step = abs(val - old); + if (step == 0) + return 0; + reg = (reg & ~(0x1F << shift)) | (val << shift); writel(reg, &anatop->reg_core);
+ /* + * The LDO ramp-up is based on 64 clock cycles of 24 MHz = 2.6 us per + * step + */ + udelay(3 * step); + return 0; }
@@ -170,8 +181,6 @@ int arch_cpu_init(void) { init_aips();
- set_ldo_voltage(LDO_SOC, 1175); /* Set VDDSOC to 1.175V */ - imx_set_wdog_powerdown(false); /* Disable PDE bit of WMCR register */
#ifdef CONFIG_APBH_DMA @@ -182,6 +191,13 @@ int arch_cpu_init(void) return 0; }
+int board_postclk_init(void) +{ + set_ldo_voltage(LDO_SOC, 1175); /* Set VDDSOC to 1.175V */ + + return 0; +} + #ifndef CONFIG_SYS_DCACHE_OFF void enable_caches(void) { diff --git a/include/configs/mx6_common.h b/include/configs/mx6_common.h index 674bcd3..514d634 100644 --- a/include/configs/mx6_common.h +++ b/include/configs/mx6_common.h @@ -20,5 +20,6 @@ #define CONFIG_ARM_ERRATA_742230 #define CONFIG_ARM_ERRATA_743622 #define CONFIG_ARM_ERRATA_751472 +#define CONFIG_BOARD_POSTCLK_INIT
#endif