2 * Regulator driver for ST's PWM Regulators
4 * Copyright (C) 2014 - STMicroelectronics Inc.
6 * Author: Lee Jones <lee.jones@linaro.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/err.h>
16 #include <linux/regulator/driver.h>
17 #include <linux/regulator/machine.h>
18 #include <linux/regulator/of_regulator.h>
20 #include <linux/of_device.h>
21 #include <linux/pwm.h>
23 #define ST_PWM_REG_PERIOD 8448
25 struct st_pwm_regulator_pdata {
26 const struct regulator_desc *desc;
27 struct st_pwm_voltages *duty_cycle_table;
30 struct st_pwm_regulator_data {
31 const struct st_pwm_regulator_pdata *pdata;
32 struct pwm_device *pwm;
37 struct st_pwm_voltages {
39 unsigned int dutycycle;
42 static int st_pwm_regulator_get_voltage(struct regulator_dev *dev)
44 struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
46 return drvdata->pdata->duty_cycle_table[drvdata->state].uV;
49 static int st_pwm_regulator_set_voltage_sel(struct regulator_dev *dev,
52 struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
56 if (selector >= dev->desc->n_voltages)
59 dutycycle = (ST_PWM_REG_PERIOD / 100) *
60 drvdata->pdata->duty_cycle_table[selector].dutycycle;
62 ret = pwm_config(drvdata->pwm, dutycycle, ST_PWM_REG_PERIOD);
64 dev_err(&dev->dev, "Failed to configure PWM\n");
68 drvdata->state = selector;
70 if (!drvdata->enabled) {
71 ret = pwm_enable(drvdata->pwm);
73 dev_err(&dev->dev, "Failed to enable PWM\n");
76 drvdata->enabled = true;
82 static int st_pwm_regulator_list_voltage(struct regulator_dev *dev,
85 struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
87 if (selector >= dev->desc->n_voltages)
90 return drvdata->pdata->duty_cycle_table[selector].uV;
93 static struct regulator_ops st_pwm_regulator_voltage_ops = {
94 .set_voltage_sel = st_pwm_regulator_set_voltage_sel,
95 .get_voltage = st_pwm_regulator_get_voltage,
96 .list_voltage = st_pwm_regulator_list_voltage,
97 .map_voltage = regulator_map_voltage_iterate,
100 static struct st_pwm_voltages b2105_duty_cycle_table[] = {
101 { .uV = 1114000, .dutycycle = 0, },
102 { .uV = 1095000, .dutycycle = 10, },
103 { .uV = 1076000, .dutycycle = 20, },
104 { .uV = 1056000, .dutycycle = 30, },
105 { .uV = 1036000, .dutycycle = 40, },
106 { .uV = 1016000, .dutycycle = 50, },
107 /* WARNING: Values above 50% duty-cycle cause boot failures. */
110 static const struct regulator_desc b2105_desc = {
111 .name = "b2105-pwm-regulator",
112 .ops = &st_pwm_regulator_voltage_ops,
113 .type = REGULATOR_VOLTAGE,
114 .owner = THIS_MODULE,
115 .n_voltages = ARRAY_SIZE(b2105_duty_cycle_table),
116 .supply_name = "pwm",
119 static const struct st_pwm_regulator_pdata b2105_info = {
121 .duty_cycle_table = b2105_duty_cycle_table,
124 static struct of_device_id st_pwm_of_match[] = {
125 { .compatible = "st,b2105-pwm-regulator", .data = &b2105_info, },
128 MODULE_DEVICE_TABLE(of, st_pwm_of_match);
130 static int st_pwm_regulator_probe(struct platform_device *pdev)
132 struct st_pwm_regulator_data *drvdata;
133 struct regulator_dev *regulator;
134 struct regulator_config config = { };
135 struct device_node *np = pdev->dev.of_node;
136 const struct of_device_id *of_match;
139 dev_err(&pdev->dev, "Device Tree node missing\n");
143 drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
147 of_match = of_match_device(st_pwm_of_match, &pdev->dev);
149 dev_err(&pdev->dev, "failed to match of device\n");
152 drvdata->pdata = of_match->data;
154 config.init_data = of_get_regulator_init_data(&pdev->dev, np);
155 if (!config.init_data)
159 config.dev = &pdev->dev;
160 config.driver_data = drvdata;
162 drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
163 if (IS_ERR(drvdata->pwm)) {
164 dev_err(&pdev->dev, "Failed to get PWM\n");
165 return PTR_ERR(drvdata->pwm);
168 regulator = devm_regulator_register(&pdev->dev,
169 drvdata->pdata->desc, &config);
170 if (IS_ERR(regulator)) {
171 dev_err(&pdev->dev, "Failed to register regulator %s\n",
172 drvdata->pdata->desc->name);
173 return PTR_ERR(regulator);
179 static struct platform_driver st_pwm_regulator_driver = {
181 .name = "st-pwm-regulator",
182 .owner = THIS_MODULE,
183 .of_match_table = of_match_ptr(st_pwm_of_match),
185 .probe = st_pwm_regulator_probe,
188 module_platform_driver(st_pwm_regulator_driver);
190 MODULE_LICENSE("GPL");
191 MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
192 MODULE_DESCRIPTION("ST PWM Regulator Driver");
193 MODULE_ALIAS("platform:st_pwm-regulator");