diff options
Diffstat (limited to 'drivers/regulator')
| -rw-r--r-- | drivers/regulator/pwm-regulator.c | 114 |
1 files changed, 106 insertions, 8 deletions
diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 25560fc519b7..dac145db305c 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -10,6 +10,7 @@ * published by the Free Software Foundation. */ +#include <linux/delay.h> #include <linux/module.h> #include <linux/init.h> #include <linux/err.h> @@ -21,9 +22,16 @@ #include <linux/pwm.h> struct pwm_regulator_data { - struct pwm_voltages *duty_cycle_table; + /* Shared */ struct pwm_device *pwm; + + /* Voltage table */ + struct pwm_voltages *duty_cycle_table; int state; + + /* Continuous voltage */ + u32 max_duty_cycle; + int volt_uV; }; struct pwm_voltages { @@ -31,6 +39,9 @@ struct pwm_voltages { unsigned int dutycycle; }; +/** + * Voltage table call-backs + */ static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); @@ -78,6 +89,71 @@ static int pwm_regulator_list_voltage(struct regulator_dev *rdev, return drvdata->duty_cycle_table[selector].uV; } + +/** + * Continuous voltage call-backs + */ +static int pwm_voltage_to_duty_cycle(struct regulator_dev *rdev, + int volt_mV) +{ + struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + int min_mV = rdev->constraints->min_uV / 1000; + int max_mV = rdev->constraints->max_uV / 1000; + int max_duty_cycle = drvdata->max_duty_cycle; + int vdiff = min_mV - max_mV; + int pwm_code; + int tmp; + + tmp = ((max_duty_cycle - min_mV) * max_duty_cycle) / vdiff; + pwm_code = ((tmp + max_duty_cycle) * volt_mV) / vdiff; + + if (pwm_code < 0) + pwm_code = 0; + if (pwm_code > max_duty_cycle) + pwm_code = max_duty_cycle; + + return pwm_code * 100 / max_duty_cycle; +} + +static int pwm_regulator_get_voltage(struct regulator_dev *rdev) +{ + struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + + return drvdata->volt_uV; +} + +static int pwm_regulator_set_voltage(struct regulator_dev *rdev, + int min_uV, int max_uV, + unsigned *selector) +{ + struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + unsigned int ramp_delay = rdev->constraints->ramp_delay; + int duty_cycle; + int ret; + + duty_cycle = pwm_voltage_to_duty_cycle(rdev, min_uV / 1000); + + ret = pwm_config(drvdata->pwm, + (drvdata->pwm->period / 100) * duty_cycle, + drvdata->pwm->period); + if (ret) { + dev_err(&rdev->dev, "Failed to configure PWM\n"); + return ret; + } + + ret = pwm_enable(drvdata->pwm); + if (ret) { + dev_err(&rdev->dev, "Failed to enable PWM\n"); + return ret; + } + drvdata->volt_uV = min_uV; + + /* Delay required by PWM regulator to settle to the new voltage */ + usleep_range(ramp_delay, ramp_delay + 1000); + + return 0; +} + static struct regulator_ops pwm_regulator_voltage_table_ops = { .set_voltage_sel = pwm_regulator_set_voltage_sel, .get_voltage_sel = pwm_regulator_get_voltage_sel, @@ -85,6 +161,11 @@ static struct regulator_ops pwm_regulator_voltage_table_ops = { .map_voltage = regulator_map_voltage_iterate, }; +static struct regulator_ops pwm_regulator_voltage_continuous_ops = { + .get_voltage = pwm_regulator_get_voltage, + .set_voltage = pwm_regulator_set_voltage, +}; + static struct regulator_desc pwm_regulator_desc = { .name = "pwm-regulator", .type = REGULATOR_VOLTAGE, @@ -129,6 +210,25 @@ static int pwm_regulator_init_table(struct platform_device *pdev, return 0; } +static int pwm_regulator_init_continuous(struct platform_device *pdev, + struct pwm_regulator_data *drvdata) +{ + struct device_node *np = pdev->dev.of_node; + int ret; + + ret = of_property_read_u32(np, "max-duty-cycle", + &drvdata->max_duty_cycle); + if (ret) { + dev_err(&pdev->dev, "Failed to read \"pwm-max-value\"\n"); + return ret; + } + + pwm_regulator_desc.ops = &pwm_regulator_voltage_continuous_ops; + pwm_regulator_desc.continuous_voltage_range = true; + + return 0; +} + static int pwm_regulator_probe(struct platform_device *pdev) { struct pwm_regulator_data *drvdata; @@ -146,14 +246,12 @@ static int pwm_regulator_probe(struct platform_device *pdev) if (!drvdata) return -ENOMEM; - if (of_find_property(np, "voltage-table", NULL)) { + if (of_find_property(np, "voltage-table", NULL)) ret = pwm_regulator_init_table(pdev, drvdata); - if (ret) - return ret; - } else { - dev_err(&pdev->dev, "No \"voltage-table\" supplied\n"); - return -EINVAL; - } + else + ret = pwm_regulator_init_continuous(pdev, drvdata); + if (ret) + return ret; config.init_data = of_get_regulator_init_data(&pdev->dev, np, &pwm_regulator_desc); |