diff options
| author | Anson Huang <b20788@freescale.com> | 2013-01-31 11:23:53 -0500 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2013-01-31 14:40:49 +0800 |
| commit | 9ee417c07479b9a87d0808dd3c8b4ce3925983f1 (patch) | |
| tree | 639728c1c15217843d2d4641cdf13c5146d39aa8 /drivers/regulator | |
| parent | 949db153b6466c6f7cad5a427ecea94985927311 (diff) | |
regulators: anatop: add set_voltage_time_sel interface
some of anatop's regulators(cpu, vddpu and vddsoc) have
register settings about LDO's step time, which will impact
the LDO ramp up speed, need to use set_voltage_time_sel
interface to add necessary delay everytime LDOs' voltage
is increased.
offset 0x170:
bit [24-25]: cpu
bit [26-27]: vddpu
bit [28-29]: vddsoc
field definition:
0'b00: 64 cycles of 24M clock;
0'b01: 128 cycles of 24M clock;
0'b02: 256 cycles of 24M clock;
0'b03: 512 cycles of 24M clock;
Signed-off-by: Anson Huang <b20788@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'drivers/regulator')
| -rw-r--r-- | drivers/regulator/anatop-regulator.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/regulator/anatop-regulator.c b/drivers/regulator/anatop-regulator.c index 8f39cac661d2..0df9c6a97604 100644 --- a/drivers/regulator/anatop-regulator.c +++ b/drivers/regulator/anatop-regulator.c @@ -31,12 +31,18 @@ #include <linux/regulator/driver.h> #include <linux/regulator/of_regulator.h> +#define LDO_RAMP_UP_UNIT_IN_CYCLES 64 /* 64 cycles per step */ +#define LDO_RAMP_UP_FREQ_IN_MHZ 24 /* cycle based on 24M OSC */ + struct anatop_regulator { const char *name; u32 control_reg; struct regmap *anatop; int vol_bit_shift; int vol_bit_width; + u32 delay_reg; + int delay_bit_shift; + int delay_bit_width; int min_bit_val; int min_voltage; int max_voltage; @@ -55,6 +61,32 @@ static int anatop_regmap_set_voltage_sel(struct regulator_dev *reg, return regulator_set_voltage_sel_regmap(reg, selector); } +static int anatop_regmap_set_voltage_time_sel(struct regulator_dev *reg, + unsigned int old_sel, + unsigned int new_sel) +{ + struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg); + u32 val; + int ret = 0; + + /* check whether need to care about LDO ramp up speed */ + if (anatop_reg->delay_bit_width && new_sel > old_sel) { + /* + * the delay for LDO ramp up time is + * based on the register setting, we need + * to calculate how many steps LDO need to + * ramp up, and how much delay needed. (us) + */ + regmap_read(anatop_reg->anatop, anatop_reg->delay_reg, &val); + val = (val >> anatop_reg->delay_bit_shift) & + ((1 << anatop_reg->delay_bit_width) - 1); + ret = (new_sel - old_sel) * ((LDO_RAMP_UP_UNIT_IN_CYCLES << + val) / LDO_RAMP_UP_FREQ_IN_MHZ + 1); + } + + return ret; +} + static int anatop_regmap_get_voltage_sel(struct regulator_dev *reg) { struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg); @@ -67,6 +99,7 @@ static int anatop_regmap_get_voltage_sel(struct regulator_dev *reg) static struct regulator_ops anatop_rops = { .set_voltage_sel = anatop_regmap_set_voltage_sel, + .set_voltage_time_sel = anatop_regmap_set_voltage_time_sel, .get_voltage_sel = anatop_regmap_get_voltage_sel, .list_voltage = regulator_list_voltage_linear, .map_voltage = regulator_map_voltage_linear, @@ -143,6 +176,14 @@ static int anatop_regulator_probe(struct platform_device *pdev) goto anatop_probe_end; } + /* read LDO ramp up setting, only for core reg */ + of_property_read_u32(np, "anatop-delay-reg-offset", + &sreg->delay_reg); + of_property_read_u32(np, "anatop-delay-bit-width", + &sreg->delay_bit_width); + of_property_read_u32(np, "anatop-delay-bit-shift", + &sreg->delay_bit_shift); + rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage) / 25000 + 1 + sreg->min_bit_val; rdesc->min_uV = sreg->min_voltage; |