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mx6: soc: Add the required LDO ramp up delay

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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>
This commit is contained in:
Fabio Estevam 2013-12-26 14:51:34 -02:00 • committed by Stefano Babic
parent 3d622b78bd
commit 39f0ac9347
2 changed files with 20 additions and 3 deletions
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22
arch/arm/cpu/armv7/mx6/soc.c
View file

@ -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)
{

1
include/configs/mx6_common.h
View file

@ -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