Lee Jones | 4a5d301 | 2014-03-21 10:21:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Regulator driver for ST's PWM Regulators |
| 3 | * |
| 4 | * Copyright (C) 2014 - STMicroelectronics Inc. |
| 5 | * |
| 6 | * Author: Lee Jones <lee.jones@linaro.org> |
| 7 | * |
| 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. |
| 11 | */ |
| 12 | |
| 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> |
| 19 | #include <linux/of.h> |
| 20 | #include <linux/of_device.h> |
| 21 | #include <linux/pwm.h> |
| 22 | |
| 23 | #define ST_PWM_REG_PERIOD 8448 |
| 24 | |
| 25 | struct st_pwm_regulator_pdata { |
| 26 | const struct regulator_desc *desc; |
| 27 | struct st_pwm_voltages *duty_cycle_table; |
| 28 | }; |
| 29 | |
| 30 | struct st_pwm_regulator_data { |
| 31 | const struct st_pwm_regulator_pdata *pdata; |
| 32 | struct pwm_device *pwm; |
| 33 | bool enabled; |
| 34 | int state; |
| 35 | }; |
| 36 | |
| 37 | struct st_pwm_voltages { |
| 38 | unsigned int uV; |
| 39 | unsigned int dutycycle; |
| 40 | }; |
| 41 | |
Axel Lin | d8eb6fa | 2014-03-22 07:22:38 +0800 | [diff] [blame] | 42 | static int st_pwm_regulator_get_voltage_sel(struct regulator_dev *dev) |
Lee Jones | 4a5d301 | 2014-03-21 10:21:36 +0000 | [diff] [blame] | 43 | { |
| 44 | struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
| 45 | |
Axel Lin | d8eb6fa | 2014-03-22 07:22:38 +0800 | [diff] [blame] | 46 | return drvdata->state; |
Lee Jones | 4a5d301 | 2014-03-21 10:21:36 +0000 | [diff] [blame] | 47 | } |
| 48 | |
| 49 | static int st_pwm_regulator_set_voltage_sel(struct regulator_dev *dev, |
| 50 | unsigned selector) |
| 51 | { |
| 52 | struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
| 53 | int dutycycle; |
| 54 | int ret; |
| 55 | |
Lee Jones | 4a5d301 | 2014-03-21 10:21:36 +0000 | [diff] [blame] | 56 | dutycycle = (ST_PWM_REG_PERIOD / 100) * |
| 57 | drvdata->pdata->duty_cycle_table[selector].dutycycle; |
| 58 | |
| 59 | ret = pwm_config(drvdata->pwm, dutycycle, ST_PWM_REG_PERIOD); |
| 60 | if (ret) { |
| 61 | dev_err(&dev->dev, "Failed to configure PWM\n"); |
| 62 | return ret; |
| 63 | } |
| 64 | |
| 65 | drvdata->state = selector; |
| 66 | |
| 67 | if (!drvdata->enabled) { |
| 68 | ret = pwm_enable(drvdata->pwm); |
| 69 | if (ret) { |
| 70 | dev_err(&dev->dev, "Failed to enable PWM\n"); |
| 71 | return ret; |
| 72 | } |
| 73 | drvdata->enabled = true; |
| 74 | } |
| 75 | |
| 76 | return 0; |
| 77 | } |
| 78 | |
| 79 | static int st_pwm_regulator_list_voltage(struct regulator_dev *dev, |
| 80 | unsigned selector) |
| 81 | { |
| 82 | struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
| 83 | |
| 84 | if (selector >= dev->desc->n_voltages) |
| 85 | return -EINVAL; |
| 86 | |
| 87 | return drvdata->pdata->duty_cycle_table[selector].uV; |
| 88 | } |
| 89 | |
| 90 | static struct regulator_ops st_pwm_regulator_voltage_ops = { |
| 91 | .set_voltage_sel = st_pwm_regulator_set_voltage_sel, |
Axel Lin | d8eb6fa | 2014-03-22 07:22:38 +0800 | [diff] [blame] | 92 | .get_voltage_sel = st_pwm_regulator_get_voltage_sel, |
Lee Jones | 4a5d301 | 2014-03-21 10:21:36 +0000 | [diff] [blame] | 93 | .list_voltage = st_pwm_regulator_list_voltage, |
| 94 | .map_voltage = regulator_map_voltage_iterate, |
| 95 | }; |
| 96 | |
| 97 | static struct st_pwm_voltages b2105_duty_cycle_table[] = { |
| 98 | { .uV = 1114000, .dutycycle = 0, }, |
| 99 | { .uV = 1095000, .dutycycle = 10, }, |
| 100 | { .uV = 1076000, .dutycycle = 20, }, |
| 101 | { .uV = 1056000, .dutycycle = 30, }, |
| 102 | { .uV = 1036000, .dutycycle = 40, }, |
| 103 | { .uV = 1016000, .dutycycle = 50, }, |
| 104 | /* WARNING: Values above 50% duty-cycle cause boot failures. */ |
| 105 | }; |
| 106 | |
| 107 | static const struct regulator_desc b2105_desc = { |
| 108 | .name = "b2105-pwm-regulator", |
| 109 | .ops = &st_pwm_regulator_voltage_ops, |
| 110 | .type = REGULATOR_VOLTAGE, |
| 111 | .owner = THIS_MODULE, |
| 112 | .n_voltages = ARRAY_SIZE(b2105_duty_cycle_table), |
| 113 | .supply_name = "pwm", |
| 114 | }; |
| 115 | |
| 116 | static const struct st_pwm_regulator_pdata b2105_info = { |
| 117 | .desc = &b2105_desc, |
| 118 | .duty_cycle_table = b2105_duty_cycle_table, |
| 119 | }; |
| 120 | |
Jingoo Han | a74cf0c | 2014-05-07 17:08:35 +0900 | [diff] [blame] | 121 | static const struct of_device_id st_pwm_of_match[] = { |
Lee Jones | 4a5d301 | 2014-03-21 10:21:36 +0000 | [diff] [blame] | 122 | { .compatible = "st,b2105-pwm-regulator", .data = &b2105_info, }, |
| 123 | { }, |
| 124 | }; |
| 125 | MODULE_DEVICE_TABLE(of, st_pwm_of_match); |
| 126 | |
| 127 | static int st_pwm_regulator_probe(struct platform_device *pdev) |
| 128 | { |
| 129 | struct st_pwm_regulator_data *drvdata; |
| 130 | struct regulator_dev *regulator; |
| 131 | struct regulator_config config = { }; |
| 132 | struct device_node *np = pdev->dev.of_node; |
| 133 | const struct of_device_id *of_match; |
| 134 | |
| 135 | if (!np) { |
| 136 | dev_err(&pdev->dev, "Device Tree node missing\n"); |
| 137 | return -EINVAL; |
| 138 | } |
| 139 | |
| 140 | drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); |
| 141 | if (!drvdata) |
| 142 | return -ENOMEM; |
| 143 | |
| 144 | of_match = of_match_device(st_pwm_of_match, &pdev->dev); |
| 145 | if (!of_match) { |
| 146 | dev_err(&pdev->dev, "failed to match of device\n"); |
| 147 | return -ENODEV; |
| 148 | } |
| 149 | drvdata->pdata = of_match->data; |
| 150 | |
| 151 | config.init_data = of_get_regulator_init_data(&pdev->dev, np); |
| 152 | if (!config.init_data) |
| 153 | return -ENOMEM; |
| 154 | |
| 155 | config.of_node = np; |
| 156 | config.dev = &pdev->dev; |
| 157 | config.driver_data = drvdata; |
| 158 | |
| 159 | drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); |
| 160 | if (IS_ERR(drvdata->pwm)) { |
| 161 | dev_err(&pdev->dev, "Failed to get PWM\n"); |
| 162 | return PTR_ERR(drvdata->pwm); |
| 163 | } |
| 164 | |
| 165 | regulator = devm_regulator_register(&pdev->dev, |
| 166 | drvdata->pdata->desc, &config); |
| 167 | if (IS_ERR(regulator)) { |
| 168 | dev_err(&pdev->dev, "Failed to register regulator %s\n", |
| 169 | drvdata->pdata->desc->name); |
| 170 | return PTR_ERR(regulator); |
| 171 | } |
| 172 | |
| 173 | return 0; |
| 174 | } |
| 175 | |
| 176 | static struct platform_driver st_pwm_regulator_driver = { |
| 177 | .driver = { |
| 178 | .name = "st-pwm-regulator", |
| 179 | .owner = THIS_MODULE, |
| 180 | .of_match_table = of_match_ptr(st_pwm_of_match), |
| 181 | }, |
| 182 | .probe = st_pwm_regulator_probe, |
| 183 | }; |
| 184 | |
| 185 | module_platform_driver(st_pwm_regulator_driver); |
| 186 | |
| 187 | MODULE_LICENSE("GPL"); |
| 188 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); |
| 189 | MODULE_DESCRIPTION("ST PWM Regulator Driver"); |
| 190 | MODULE_ALIAS("platform:st_pwm-regulator"); |