1aa66cc66SChris Zhong /* 2aa66cc66SChris Zhong * Regulator driver for PWM Regulators 3aa66cc66SChris Zhong * 4aa66cc66SChris Zhong * Copyright (C) 2014 - STMicroelectronics Inc. 5aa66cc66SChris Zhong * 6aa66cc66SChris Zhong * Author: Lee Jones <lee.jones@linaro.org> 7aa66cc66SChris Zhong * 8aa66cc66SChris Zhong * This program is free software; you can redistribute it and/or modify 9aa66cc66SChris Zhong * it under the terms of the GNU General Public License version 2 as 10aa66cc66SChris Zhong * published by the Free Software Foundation. 11aa66cc66SChris Zhong */ 12aa66cc66SChris Zhong 13aa66cc66SChris Zhong #include <linux/module.h> 14aa66cc66SChris Zhong #include <linux/init.h> 15aa66cc66SChris Zhong #include <linux/err.h> 16aa66cc66SChris Zhong #include <linux/regulator/driver.h> 17aa66cc66SChris Zhong #include <linux/regulator/machine.h> 18aa66cc66SChris Zhong #include <linux/regulator/of_regulator.h> 19aa66cc66SChris Zhong #include <linux/of.h> 20aa66cc66SChris Zhong #include <linux/of_device.h> 21aa66cc66SChris Zhong #include <linux/pwm.h> 22aa66cc66SChris Zhong 23aa66cc66SChris Zhong struct pwm_regulator_data { 24aa66cc66SChris Zhong struct regulator_desc desc; 25aa66cc66SChris Zhong struct pwm_voltages *duty_cycle_table; 26aa66cc66SChris Zhong struct pwm_device *pwm; 27aa66cc66SChris Zhong bool enabled; 28aa66cc66SChris Zhong int state; 29aa66cc66SChris Zhong }; 30aa66cc66SChris Zhong 31aa66cc66SChris Zhong struct pwm_voltages { 32aa66cc66SChris Zhong unsigned int uV; 33aa66cc66SChris Zhong unsigned int dutycycle; 34aa66cc66SChris Zhong }; 35aa66cc66SChris Zhong 36aa66cc66SChris Zhong static int pwm_regulator_get_voltage_sel(struct regulator_dev *dev) 37aa66cc66SChris Zhong { 38aa66cc66SChris Zhong struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); 39aa66cc66SChris Zhong 40aa66cc66SChris Zhong return drvdata->state; 41aa66cc66SChris Zhong } 42aa66cc66SChris Zhong 43aa66cc66SChris Zhong static int pwm_regulator_set_voltage_sel(struct regulator_dev *dev, 44aa66cc66SChris Zhong unsigned selector) 45aa66cc66SChris Zhong { 46aa66cc66SChris Zhong struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); 47aa66cc66SChris Zhong unsigned int pwm_reg_period; 48aa66cc66SChris Zhong int dutycycle; 49aa66cc66SChris Zhong int ret; 50aa66cc66SChris Zhong 51aa66cc66SChris Zhong pwm_reg_period = pwm_get_period(drvdata->pwm); 52aa66cc66SChris Zhong 53aa66cc66SChris Zhong dutycycle = (pwm_reg_period * 54aa66cc66SChris Zhong drvdata->duty_cycle_table[selector].dutycycle) / 100; 55aa66cc66SChris Zhong 56aa66cc66SChris Zhong ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period); 57aa66cc66SChris Zhong if (ret) { 58aa66cc66SChris Zhong dev_err(&dev->dev, "Failed to configure PWM\n"); 59aa66cc66SChris Zhong return ret; 60aa66cc66SChris Zhong } 61aa66cc66SChris Zhong 62aa66cc66SChris Zhong drvdata->state = selector; 63aa66cc66SChris Zhong 64aa66cc66SChris Zhong if (!drvdata->enabled) { 65aa66cc66SChris Zhong ret = pwm_enable(drvdata->pwm); 66aa66cc66SChris Zhong if (ret) { 67aa66cc66SChris Zhong dev_err(&dev->dev, "Failed to enable PWM\n"); 68aa66cc66SChris Zhong return ret; 69aa66cc66SChris Zhong } 70aa66cc66SChris Zhong drvdata->enabled = true; 71aa66cc66SChris Zhong } 72aa66cc66SChris Zhong 73aa66cc66SChris Zhong return 0; 74aa66cc66SChris Zhong } 75aa66cc66SChris Zhong 76aa66cc66SChris Zhong static int pwm_regulator_list_voltage(struct regulator_dev *dev, 77aa66cc66SChris Zhong unsigned selector) 78aa66cc66SChris Zhong { 79aa66cc66SChris Zhong struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); 80aa66cc66SChris Zhong 81aa66cc66SChris Zhong if (selector >= drvdata->desc.n_voltages) 82aa66cc66SChris Zhong return -EINVAL; 83aa66cc66SChris Zhong 84aa66cc66SChris Zhong return drvdata->duty_cycle_table[selector].uV; 85aa66cc66SChris Zhong } 86aa66cc66SChris Zhong 87aa66cc66SChris Zhong static struct regulator_ops pwm_regulator_voltage_ops = { 88aa66cc66SChris Zhong .set_voltage_sel = pwm_regulator_set_voltage_sel, 89aa66cc66SChris Zhong .get_voltage_sel = pwm_regulator_get_voltage_sel, 90aa66cc66SChris Zhong .list_voltage = pwm_regulator_list_voltage, 91aa66cc66SChris Zhong .map_voltage = regulator_map_voltage_iterate, 92aa66cc66SChris Zhong }; 93aa66cc66SChris Zhong 94aa66cc66SChris Zhong static const struct regulator_desc pwm_regulator_desc = { 95aa66cc66SChris Zhong .name = "pwm-regulator", 96aa66cc66SChris Zhong .ops = &pwm_regulator_voltage_ops, 97aa66cc66SChris Zhong .type = REGULATOR_VOLTAGE, 98aa66cc66SChris Zhong .owner = THIS_MODULE, 99aa66cc66SChris Zhong .supply_name = "pwm", 100aa66cc66SChris Zhong }; 101aa66cc66SChris Zhong 102aa66cc66SChris Zhong static int pwm_regulator_probe(struct platform_device *pdev) 103aa66cc66SChris Zhong { 104aa66cc66SChris Zhong struct pwm_regulator_data *drvdata; 105aa66cc66SChris Zhong struct property *prop; 106aa66cc66SChris Zhong struct regulator_dev *regulator; 107aa66cc66SChris Zhong struct regulator_config config = { }; 108aa66cc66SChris Zhong struct device_node *np = pdev->dev.of_node; 109aa66cc66SChris Zhong int length, ret; 110aa66cc66SChris Zhong 111aa66cc66SChris Zhong if (!np) { 112aa66cc66SChris Zhong dev_err(&pdev->dev, "Device Tree node missing\n"); 113aa66cc66SChris Zhong return -EINVAL; 114aa66cc66SChris Zhong } 115aa66cc66SChris Zhong 116aa66cc66SChris Zhong drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); 117aa66cc66SChris Zhong if (!drvdata) 118aa66cc66SChris Zhong return -ENOMEM; 119aa66cc66SChris Zhong 120aa66cc66SChris Zhong memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(pwm_regulator_desc)); 121aa66cc66SChris Zhong 122aa66cc66SChris Zhong /* determine the number of voltage-table */ 123aa66cc66SChris Zhong prop = of_find_property(np, "voltage-table", &length); 124aa66cc66SChris Zhong if (!prop) { 125aa66cc66SChris Zhong dev_err(&pdev->dev, "No voltage-table\n"); 126aa66cc66SChris Zhong return -EINVAL; 127aa66cc66SChris Zhong } 128aa66cc66SChris Zhong 129aa66cc66SChris Zhong if ((length < sizeof(*drvdata->duty_cycle_table)) || 130aa66cc66SChris Zhong (length % sizeof(*drvdata->duty_cycle_table))) { 131aa66cc66SChris Zhong dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n", 132aa66cc66SChris Zhong length); 133aa66cc66SChris Zhong return -EINVAL; 134aa66cc66SChris Zhong } 135aa66cc66SChris Zhong 136aa66cc66SChris Zhong drvdata->desc.n_voltages = length / sizeof(*drvdata->duty_cycle_table); 137aa66cc66SChris Zhong 138aa66cc66SChris Zhong drvdata->duty_cycle_table = devm_kzalloc(&pdev->dev, 139aa66cc66SChris Zhong length, GFP_KERNEL); 140aa66cc66SChris Zhong if (!drvdata->duty_cycle_table) 141aa66cc66SChris Zhong return -ENOMEM; 142aa66cc66SChris Zhong 143aa66cc66SChris Zhong /* read voltage table from DT property */ 144aa66cc66SChris Zhong ret = of_property_read_u32_array(np, "voltage-table", 145aa66cc66SChris Zhong (u32 *)drvdata->duty_cycle_table, 146aa66cc66SChris Zhong length / sizeof(u32)); 147aa66cc66SChris Zhong if (ret < 0) { 148aa66cc66SChris Zhong dev_err(&pdev->dev, "read voltage-table failed\n"); 149aa66cc66SChris Zhong return ret; 150aa66cc66SChris Zhong } 151aa66cc66SChris Zhong 152*072e78b1SJavier Martinez Canillas config.init_data = of_get_regulator_init_data(&pdev->dev, np, 153*072e78b1SJavier Martinez Canillas &drvdata->desc); 154aa66cc66SChris Zhong if (!config.init_data) 155aa66cc66SChris Zhong return -ENOMEM; 156aa66cc66SChris Zhong 157aa66cc66SChris Zhong config.of_node = np; 158aa66cc66SChris Zhong config.dev = &pdev->dev; 159aa66cc66SChris Zhong config.driver_data = drvdata; 160aa66cc66SChris Zhong 161aa66cc66SChris Zhong drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); 162aa66cc66SChris Zhong if (IS_ERR(drvdata->pwm)) { 163aa66cc66SChris Zhong dev_err(&pdev->dev, "Failed to get PWM\n"); 164aa66cc66SChris Zhong return PTR_ERR(drvdata->pwm); 165aa66cc66SChris Zhong } 166aa66cc66SChris Zhong 167aa66cc66SChris Zhong regulator = devm_regulator_register(&pdev->dev, 168aa66cc66SChris Zhong &drvdata->desc, &config); 169aa66cc66SChris Zhong if (IS_ERR(regulator)) { 170aa66cc66SChris Zhong dev_err(&pdev->dev, "Failed to register regulator %s\n", 171aa66cc66SChris Zhong drvdata->desc.name); 172aa66cc66SChris Zhong return PTR_ERR(regulator); 173aa66cc66SChris Zhong } 174aa66cc66SChris Zhong 175aa66cc66SChris Zhong return 0; 176aa66cc66SChris Zhong } 177aa66cc66SChris Zhong 178aa66cc66SChris Zhong static const struct of_device_id pwm_of_match[] = { 179aa66cc66SChris Zhong { .compatible = "pwm-regulator" }, 180aa66cc66SChris Zhong { }, 181aa66cc66SChris Zhong }; 182aa66cc66SChris Zhong MODULE_DEVICE_TABLE(of, pwm_of_match); 183aa66cc66SChris Zhong 184aa66cc66SChris Zhong static struct platform_driver pwm_regulator_driver = { 185aa66cc66SChris Zhong .driver = { 186aa66cc66SChris Zhong .name = "pwm-regulator", 187aa66cc66SChris Zhong .owner = THIS_MODULE, 188aa66cc66SChris Zhong .of_match_table = of_match_ptr(pwm_of_match), 189aa66cc66SChris Zhong }, 190aa66cc66SChris Zhong .probe = pwm_regulator_probe, 191aa66cc66SChris Zhong }; 192aa66cc66SChris Zhong 193aa66cc66SChris Zhong module_platform_driver(pwm_regulator_driver); 194aa66cc66SChris Zhong 195aa66cc66SChris Zhong MODULE_LICENSE("GPL"); 196aa66cc66SChris Zhong MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); 197aa66cc66SChris Zhong MODULE_DESCRIPTION("PWM Regulator Driver"); 198aa66cc66SChris Zhong MODULE_ALIAS("platform:pwm-regulator"); 199