regulator: Add new driver for ST's PWM controlled voltage regulators
On some STMicroelectronics hardware reside regulators consisting partly of a PWM input connected to the feedback loop. As the PWM duty-cycle is varied the output voltage adapts. This driver allows us to vary the output voltage by adapting the PWM input duty-cycle. Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>hifive-unleashed-5.1
Lee Jones
Mark Brown
parent
38dbfb59d1
commit
4a5d301328
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@ -432,6 +432,12 @@ config REGULATOR_S5M8767
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via I2C bus. S5M8767A have 9 Bucks and 28 LDOs output and
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supports DVS mode with 8bits of output voltage control.
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config REGULATOR_ST_PWM
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tristate "STMicroelectronics PWM voltage regulator"
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depends on ARCH_STI
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help
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This driver supports ST's PWM controlled voltage regulators.
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config REGULATOR_TI_ABB
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tristate "TI Adaptive Body Bias on-chip LDO"
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depends on ARCH_OMAP
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@ -59,6 +59,7 @@ obj-$(CONFIG_REGULATOR_PCF50633) += pcf50633-regulator.o
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obj-$(CONFIG_REGULATOR_RC5T583) += rc5t583-regulator.o
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obj-$(CONFIG_REGULATOR_S2MPS11) += s2mps11.o
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obj-$(CONFIG_REGULATOR_S5M8767) += s5m8767.o
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obj-$(CONFIG_REGULATOR_ST_PWM) += st-pwm.o
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obj-$(CONFIG_REGULATOR_STW481X_VMMC) += stw481x-vmmc.o
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obj-$(CONFIG_REGULATOR_TI_ABB) += ti-abb-regulator.o
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obj-$(CONFIG_REGULATOR_TPS6105X) += tps6105x-regulator.o
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@ -0,0 +1,193 @@
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/*
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* Regulator driver for ST's PWM Regulators
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*
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* Copyright (C) 2014 - STMicroelectronics Inc.
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*
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* Author: Lee Jones <lee.jones@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/err.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/machine.h>
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#include <linux/regulator/of_regulator.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/pwm.h>
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#define ST_PWM_REG_PERIOD 8448
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struct st_pwm_regulator_pdata {
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const struct regulator_desc *desc;
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struct st_pwm_voltages *duty_cycle_table;
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};
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struct st_pwm_regulator_data {
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const struct st_pwm_regulator_pdata *pdata;
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struct pwm_device *pwm;
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bool enabled;
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int state;
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};
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struct st_pwm_voltages {
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unsigned int uV;
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unsigned int dutycycle;
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};
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static int st_pwm_regulator_get_voltage(struct regulator_dev *dev)
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{
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struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
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return drvdata->pdata->duty_cycle_table[drvdata->state].uV;
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}
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static int st_pwm_regulator_set_voltage_sel(struct regulator_dev *dev,
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unsigned selector)
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{
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struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
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int dutycycle;
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int ret;
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if (selector >= dev->desc->n_voltages)
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return -EINVAL;
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dutycycle = (ST_PWM_REG_PERIOD / 100) *
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drvdata->pdata->duty_cycle_table[selector].dutycycle;
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ret = pwm_config(drvdata->pwm, dutycycle, ST_PWM_REG_PERIOD);
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if (ret) {
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dev_err(&dev->dev, "Failed to configure PWM\n");
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return ret;
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}
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drvdata->state = selector;
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if (!drvdata->enabled) {
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ret = pwm_enable(drvdata->pwm);
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if (ret) {
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dev_err(&dev->dev, "Failed to enable PWM\n");
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return ret;
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}
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drvdata->enabled = true;
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}
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return 0;
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}
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static int st_pwm_regulator_list_voltage(struct regulator_dev *dev,
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unsigned selector)
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{
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struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
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if (selector >= dev->desc->n_voltages)
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return -EINVAL;
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return drvdata->pdata->duty_cycle_table[selector].uV;
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}
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static struct regulator_ops st_pwm_regulator_voltage_ops = {
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.set_voltage_sel = st_pwm_regulator_set_voltage_sel,
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.get_voltage = st_pwm_regulator_get_voltage,
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.list_voltage = st_pwm_regulator_list_voltage,
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.map_voltage = regulator_map_voltage_iterate,
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};
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static struct st_pwm_voltages b2105_duty_cycle_table[] = {
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{ .uV = 1114000, .dutycycle = 0, },
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{ .uV = 1095000, .dutycycle = 10, },
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{ .uV = 1076000, .dutycycle = 20, },
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{ .uV = 1056000, .dutycycle = 30, },
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{ .uV = 1036000, .dutycycle = 40, },
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{ .uV = 1016000, .dutycycle = 50, },
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/* WARNING: Values above 50% duty-cycle cause boot failures. */
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};
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static const struct regulator_desc b2105_desc = {
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.name = "b2105-pwm-regulator",
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.ops = &st_pwm_regulator_voltage_ops,
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.type = REGULATOR_VOLTAGE,
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.owner = THIS_MODULE,
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.n_voltages = ARRAY_SIZE(b2105_duty_cycle_table),
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.supply_name = "pwm",
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};
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static const struct st_pwm_regulator_pdata b2105_info = {
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.desc = &b2105_desc,
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.duty_cycle_table = b2105_duty_cycle_table,
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};
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static struct of_device_id st_pwm_of_match[] = {
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{ .compatible = "st,b2105-pwm-regulator", .data = &b2105_info, },
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{ },
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};
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MODULE_DEVICE_TABLE(of, st_pwm_of_match);
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static int st_pwm_regulator_probe(struct platform_device *pdev)
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{
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struct st_pwm_regulator_data *drvdata;
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struct regulator_dev *regulator;
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struct regulator_config config = { };
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struct device_node *np = pdev->dev.of_node;
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const struct of_device_id *of_match;
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if (!np) {
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dev_err(&pdev->dev, "Device Tree node missing\n");
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return -EINVAL;
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}
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drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
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if (!drvdata)
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return -ENOMEM;
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of_match = of_match_device(st_pwm_of_match, &pdev->dev);
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if (!of_match) {
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dev_err(&pdev->dev, "failed to match of device\n");
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return -ENODEV;
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}
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drvdata->pdata = of_match->data;
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config.init_data = of_get_regulator_init_data(&pdev->dev, np);
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if (!config.init_data)
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return -ENOMEM;
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config.of_node = np;
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config.dev = &pdev->dev;
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config.driver_data = drvdata;
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drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
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if (IS_ERR(drvdata->pwm)) {
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dev_err(&pdev->dev, "Failed to get PWM\n");
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return PTR_ERR(drvdata->pwm);
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}
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regulator = devm_regulator_register(&pdev->dev,
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drvdata->pdata->desc, &config);
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if (IS_ERR(regulator)) {
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dev_err(&pdev->dev, "Failed to register regulator %s\n",
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drvdata->pdata->desc->name);
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return PTR_ERR(regulator);
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}
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return 0;
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}
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static struct platform_driver st_pwm_regulator_driver = {
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.driver = {
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.name = "st-pwm-regulator",
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.owner = THIS_MODULE,
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.of_match_table = of_match_ptr(st_pwm_of_match),
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},
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.probe = st_pwm_regulator_probe,
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};
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module_platform_driver(st_pwm_regulator_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
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MODULE_DESCRIPTION("ST PWM Regulator Driver");
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MODULE_ALIAS("platform:st_pwm-regulator");
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