* published by the Free Software Foundation.
*/
+#include <linux/delay.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#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 */
+ int volt_uV;
};
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);
return drvdata->duty_cycle_table[selector].uV;
}
-static struct regulator_ops pwm_regulator_voltage_ops = {
+/**
+ * Continuous voltage call-backs
+ */
+static int pwm_voltage_to_duty_cycle_percentage(struct regulator_dev *rdev, int req_uV)
+{
+ int min_uV = rdev->constraints->min_uV;
+ int max_uV = rdev->constraints->max_uV;
+ int diff = max_uV - min_uV;
+
+ return 100 - (((req_uV * 100) - (min_uV * 100)) / diff);
+}
+
+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;
+ unsigned int period = pwm_get_period(drvdata->pwm);
+ int duty_cycle;
+ int ret;
+
+ duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV);
+
+ ret = pwm_config(drvdata->pwm, (period / 100) * duty_cycle, 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,
.list_voltage = pwm_regulator_list_voltage,
.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",
- .ops = &pwm_regulator_voltage_ops,
.type = REGULATOR_VOLTAGE,
.owner = THIS_MODULE,
.supply_name = "pwm",
};
+static int pwm_regulator_init_table(struct platform_device *pdev,
+ struct pwm_regulator_data *drvdata)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct pwm_voltages *duty_cycle_table;
+ unsigned int length = 0;
+ int ret;
+
+ of_find_property(np, "voltage-table", &length);
+
+ if ((length < sizeof(*duty_cycle_table)) ||
+ (length % sizeof(*duty_cycle_table))) {
+ dev_err(&pdev->dev,
+ "voltage-table length(%d) is invalid\n",
+ length);
+ return -EINVAL;
+ }
+
+ duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL);
+ if (!duty_cycle_table)
+ return -ENOMEM;
+
+ ret = of_property_read_u32_array(np, "voltage-table",
+ (u32 *)duty_cycle_table,
+ length / sizeof(u32));
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to read voltage-table\n");
+ return ret;
+ }
+
+ drvdata->duty_cycle_table = duty_cycle_table;
+ pwm_regulator_desc.ops = &pwm_regulator_voltage_table_ops;
+ pwm_regulator_desc.n_voltages = length / sizeof(*duty_cycle_table);
+
+ return 0;
+}
+
+static int pwm_regulator_init_continuous(struct platform_device *pdev,
+ struct pwm_regulator_data *drvdata)
+{
+ 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)
{
+ const struct regulator_init_data *init_data;
struct pwm_regulator_data *drvdata;
- struct property *prop;
struct regulator_dev *regulator;
struct regulator_config config = { };
struct device_node *np = pdev->dev.of_node;
- int length, ret;
+ int ret;
if (!np) {
dev_err(&pdev->dev, "Device Tree node missing\n");
if (!drvdata)
return -ENOMEM;
- /* determine the number of voltage-table */
- prop = of_find_property(np, "voltage-table", &length);
- if (!prop) {
- dev_err(&pdev->dev, "No voltage-table\n");
- return -EINVAL;
- }
-
- if ((length < sizeof(*drvdata->duty_cycle_table)) ||
- (length % sizeof(*drvdata->duty_cycle_table))) {
- dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n",
- length);
- return -EINVAL;
- }
-
- pwm_regulator_desc.n_voltages = length / sizeof(*drvdata->duty_cycle_table);
-
- drvdata->duty_cycle_table = devm_kzalloc(&pdev->dev,
- length, GFP_KERNEL);
- if (!drvdata->duty_cycle_table)
- return -ENOMEM;
-
- /* read voltage table from DT property */
- ret = of_property_read_u32_array(np, "voltage-table",
- (u32 *)drvdata->duty_cycle_table,
- length / sizeof(u32));
- if (ret < 0) {
- dev_err(&pdev->dev, "read voltage-table failed\n");
+ if (of_find_property(np, "voltage-table", NULL))
+ ret = pwm_regulator_init_table(pdev, drvdata);
+ 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);
- if (!config.init_data)
+ init_data = of_get_regulator_init_data(&pdev->dev, np,
+ &pwm_regulator_desc);
+ if (!init_data)
return -ENOMEM;
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)) {
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