Currently PWM regulator support the multiple voltage by
two different mechanism: Voltage table based and continuous
steps which divides duty cycle into 100 parts.
There is a use cases where entire voltage ranges from minimum
to maximum is divided into n equal steps and just providing the
steps count, the voltage table with duty cycles is linearly
calculated.
Add support to have specified linear n equal steps for specified
regulator's minimum and maximum voltage range for PWM regulators.
Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
Cc: Lee Jones <lee.jones@xxxxxxxxxx>
---
drivers/regulator/pwm-regulator.c | 76 ++++++++++++++++++++++++++++++++++-----
1 file changed, 68 insertions(+), 8 deletions(-)
diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 9db67a1..060e5cf 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -38,6 +38,9 @@ struct pwm_regulator_data {
/* Continuous voltage */
int volt_uV;
+
+ /* Regulator n linear steps */
+ unsigned int regulator_n_steps;
};
struct pwm_voltages {
@@ -65,7 +68,11 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
pwm_reg_period = pwm_get_period(drvdata->pwm);
- dutycycle = (pwm_reg_period *
+ if (drvdata->regulator_n_steps)
+ dutycycle = (pwm_reg_period * selector) /
+ (drvdata->regulator_n_steps - 1);
+ else
+ dutycycle = (pwm_reg_period *
drvdata->duty_cycle_table[selector].dutycycle) / 100;
ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period);
@@ -227,6 +234,41 @@ static int pwm_regulator_init_table(struct platform_device *pdev,
return 0;
}
+static int pwm_regulator_init_linear_steps(struct platform_device *pdev,
+ struct pwm_regulator_data *drvdata)
+{
+ struct device_node *np = pdev->dev.of_node;
+ unsigned int period;
+ u32 uval;
+ int ret;
+
+ ret = of_property_read_u32(np, "regulator-n-voltages", &uval);
+ if (ret < 0)
+ return ret;
+ if (uval < 2) {
+ dev_err(&pdev->dev, "Invalid number of voltage steps\n");
+ return -EINVAL;
+ }
+
+ period = pwm_get_period(drvdata->pwm);
+ if (period % (uval - 1)) {
+ dev_err(&pdev->dev, "PWM Period must multiple of n_voltages\n");
+ return -EINVAL;
+ }
+
+ memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops,
+ sizeof(drvdata->ops));
+ drvdata->ops.list_voltage = regulator_list_voltage_linear;
+ drvdata->ops.map_voltage = regulator_map_voltage_linear;
+
+ drvdata->regulator_n_steps = uval;
+ drvdata->desc.ops = &drvdata->ops;
+ drvdata->desc.linear_min_sel = 0;
+ drvdata->desc.n_voltages = drvdata->regulator_n_steps;
+
+ return 0;
+}
+
static int pwm_regulator_init_continuous(struct platform_device *pdev,
struct pwm_regulator_data *drvdata)
{
@@ -256,10 +298,19 @@ static int pwm_regulator_probe(struct platform_device *pdev)
if (!drvdata)
return -ENOMEM;
+ drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
+ if (IS_ERR(drvdata->pwm)) {
+ ret = PTR_ERR(drvdata->pwm);
+ dev_err(&pdev->dev, "Failed to get PWM, %d\n", ret);
+ return ret;
+ }
+
memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc));
if (of_find_property(np, "voltage-table", NULL))
ret = pwm_regulator_init_table(pdev, drvdata);
+ else if (of_find_property(np, "regulator-n-voltages", NULL))
+ ret = pwm_regulator_init_linear_steps(pdev, drvdata);
else
ret = pwm_regulator_init_continuous(pdev, drvdata);
if (ret)
@@ -270,18 +321,27 @@ static int pwm_regulator_probe(struct platform_device *pdev)
if (!init_data)
return -ENOMEM;
+ if (drvdata->regulator_n_steps) {
+ int min_uV = init_data->constraints.min_uV;
+ int max_uV = init_data->constraints.max_uV;
+ int step_uV;
+
+ if ((max_uV - min_uV) % (drvdata->regulator_n_steps - 1)) {
+ dev_err(&pdev->dev,
+ "Min/Max is not proper to get step voltage\n");
+ return -EINVAL;
+ }
+
+ step_uV = (max_uV - min_uV) / (drvdata->regulator_n_steps - 1);
+ drvdata->desc.min_uV = min_uV;
+ drvdata->desc.uV_step = step_uV;
+ }
+
config.of_node = np;
config.dev = &pdev->dev;
config.driver_data = drvdata;
config.init_data = init_data;
- drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
- if (IS_ERR(drvdata->pwm)) {
- ret = PTR_ERR(drvdata->pwm);
- dev_err(&pdev->dev, "Failed to get PWM, %d\n", ret);
- return ret;
- }
-
regulator = devm_regulator_register(&pdev->dev,
&drvdata->desc, &config);
if (IS_ERR(regulator)) {
--
2.1.4
--
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