diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/power/Kconfig | 34 | ||||
| -rw-r--r-- | drivers/power/axp209.c | 24 |
2 files changed, 58 insertions, 0 deletions
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig index 1a3852442a8..e83036fd660 100644 --- a/drivers/power/Kconfig +++ b/drivers/power/Kconfig @@ -197,6 +197,40 @@ config AXP_ALDO3_VOLT On A83T / H8 boards aldo3 is AVCC, VCC-PL, and VCC-LED, and should be 3.0V. +choice + prompt "axp pmic (a)ldo3 voltage rate control" + depends on AXP209_POWER + default AXP_ALDO3_VOLT_SLOPE_NONE + ---help--- + The AXP can slowly ramp up voltage to reduce the inrush current when + changing voltages. + Note, this does not apply when enabling/disabling LDO3. See + "axp pmic (a)ldo3 inrush quirk" below to enable a slew rate to limit + inrush current on broken board designs. + +config AXP_ALDO3_VOLT_SLOPE_NONE + bool "No voltage slope" + ---help--- + Tries to reach the next voltage setting near instantaneously. Measurements + indicate that this is about 0.0167 V/uS. + +config AXP_ALDO3_VOLT_SLOPE_16 + bool "1.6 mV per uS" + ---help--- + Increases the voltage by 1.6 mV per uS until the final voltage has + been reached. Note that the scaling is in 25 mV steps and thus + the slew rate in reality is about 25 mV/31.250 uS. + +config AXP_ALDO3_VOLT_SLOPE_08 + bool "0.8 mV per uS" + ---help--- + Increases the voltage by 0.8 mV per uS until the final voltage has + been reached. Note that the scaling is in 25 mV steps however and thus + the slew rate in reality is about 25 mV/15.625 uS. + This is the slowest supported rate. + +endchoice + config AXP_ALDO4_VOLT int "axp pmic (a)ldo4 voltage" depends on AXP209_POWER diff --git a/drivers/power/axp209.c b/drivers/power/axp209.c index 819b168a84b..cf138fc7227 100644 --- a/drivers/power/axp209.c +++ b/drivers/power/axp209.c @@ -9,6 +9,16 @@ #include <asm/arch/pmic_bus.h> #include <axp_pmic.h> +#ifdef CONFIG_AXP_ALDO3_VOLT_SLOPE_08 +# define AXP209_VRC_SLOPE AXP209_VRC_LDO3_800uV_uS +#endif +#ifdef CONFIG_AXP_ALDO3_VOLT_SLOPE_16 +# define AXP209_VRC_SLOPE AXP209_VRC_LDO3_1600uV_uS +#endif +#if defined CONFIG_AXP_ALDO3_VOLT_SLOPE_NONE || !defined AXP209_VRC_SLOPE +# define AXP209_VRC_SLOPE 0x00 +#endif + static u8 axp209_mvolt_to_cfg(int mvolt, int min, int max, int div) { if (mvolt < min) @@ -98,6 +108,20 @@ int axp_set_aldo3(unsigned int mvolt) return pmic_bus_clrbits(AXP209_OUTPUT_CTRL, AXP209_OUTPUT_CTRL_LDO3); + /* + * Some boards have trouble reaching the target voltage without causing + * great inrush currents. To prevent this, boards can enable a certain + * slope to ramp up voltage. Note, this only works when changing an + * already active power rail. When toggling power on, the AXP ramps up + * steeply at 0.0167 V/uS. + */ + rc = pmic_bus_read(AXP209_VRC_DCDC2_LDO3, &cfg); + cfg = AXP209_VRC_LDO3_SLOPE_SET(cfg, AXP209_VRC_SLOPE); + rc |= pmic_bus_write(AXP209_VRC_DCDC2_LDO3, cfg); + + if (rc) + return rc; + if (mvolt == -1) { cfg = AXP209_LDO3_VOLTAGE_FROM_LDO3IN; } else { |