Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Regulator driver for 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 | |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 13 | #include <linux/delay.h> |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 14 | #include <linux/module.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/err.h> |
| 17 | #include <linux/regulator/driver.h> |
| 18 | #include <linux/regulator/machine.h> |
| 19 | #include <linux/regulator/of_regulator.h> |
| 20 | #include <linux/of.h> |
| 21 | #include <linux/of_device.h> |
| 22 | #include <linux/pwm.h> |
| 23 | |
| 24 | struct pwm_regulator_data { |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 25 | /* Shared */ |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 26 | struct pwm_device *pwm; |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 27 | |
| 28 | /* Voltage table */ |
| 29 | struct pwm_voltages *duty_cycle_table; |
Laxman Dewangan | f907a0a | 2016-03-08 16:23:22 +0530 | [diff] [blame] | 30 | |
| 31 | /* regulator descriptor */ |
| 32 | struct regulator_desc desc; |
| 33 | |
| 34 | /* Regulator ops */ |
| 35 | struct regulator_ops ops; |
| 36 | |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 37 | int state; |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 38 | |
| 39 | /* Continuous voltage */ |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 40 | int volt_uV; |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 41 | }; |
| 42 | |
| 43 | struct pwm_voltages { |
| 44 | unsigned int uV; |
| 45 | unsigned int dutycycle; |
| 46 | }; |
| 47 | |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 48 | /** |
| 49 | * Voltage table call-backs |
| 50 | */ |
Lee Jones | ab101e3 | 2015-06-05 19:42:47 +0100 | [diff] [blame] | 51 | static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev) |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 52 | { |
Lee Jones | ab101e3 | 2015-06-05 19:42:47 +0100 | [diff] [blame] | 53 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 54 | |
| 55 | return drvdata->state; |
| 56 | } |
| 57 | |
Lee Jones | ab101e3 | 2015-06-05 19:42:47 +0100 | [diff] [blame] | 58 | static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 59 | unsigned selector) |
| 60 | { |
Lee Jones | ab101e3 | 2015-06-05 19:42:47 +0100 | [diff] [blame] | 61 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 62 | unsigned int pwm_reg_period; |
| 63 | int dutycycle; |
| 64 | int ret; |
| 65 | |
| 66 | pwm_reg_period = pwm_get_period(drvdata->pwm); |
| 67 | |
| 68 | dutycycle = (pwm_reg_period * |
| 69 | drvdata->duty_cycle_table[selector].dutycycle) / 100; |
| 70 | |
| 71 | ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period); |
| 72 | if (ret) { |
Laxman Dewangan | 5bf59bd | 2016-03-14 18:20:13 +0530 | [diff] [blame] | 73 | dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 74 | return ret; |
| 75 | } |
| 76 | |
| 77 | drvdata->state = selector; |
| 78 | |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 79 | return 0; |
| 80 | } |
| 81 | |
Lee Jones | ab101e3 | 2015-06-05 19:42:47 +0100 | [diff] [blame] | 82 | static int pwm_regulator_list_voltage(struct regulator_dev *rdev, |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 83 | unsigned selector) |
| 84 | { |
Lee Jones | ab101e3 | 2015-06-05 19:42:47 +0100 | [diff] [blame] | 85 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 86 | |
Lee Jones | ab101e3 | 2015-06-05 19:42:47 +0100 | [diff] [blame] | 87 | if (selector >= rdev->desc->n_voltages) |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 88 | return -EINVAL; |
| 89 | |
| 90 | return drvdata->duty_cycle_table[selector].uV; |
| 91 | } |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 92 | |
Boris Brezillon | 1de7d80 | 2015-09-21 11:33:28 +0200 | [diff] [blame] | 93 | static int pwm_regulator_enable(struct regulator_dev *dev) |
| 94 | { |
| 95 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
| 96 | |
| 97 | return pwm_enable(drvdata->pwm); |
| 98 | } |
| 99 | |
| 100 | static int pwm_regulator_disable(struct regulator_dev *dev) |
| 101 | { |
| 102 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
| 103 | |
| 104 | pwm_disable(drvdata->pwm); |
| 105 | |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | static int pwm_regulator_is_enabled(struct regulator_dev *dev) |
| 110 | { |
| 111 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
| 112 | |
| 113 | return pwm_is_enabled(drvdata->pwm); |
| 114 | } |
| 115 | |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 116 | static int pwm_regulator_get_voltage(struct regulator_dev *rdev) |
| 117 | { |
| 118 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
| 119 | |
| 120 | return drvdata->volt_uV; |
| 121 | } |
| 122 | |
| 123 | static int pwm_regulator_set_voltage(struct regulator_dev *rdev, |
| 124 | int min_uV, int max_uV, |
| 125 | unsigned *selector) |
| 126 | { |
| 127 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
| 128 | unsigned int ramp_delay = rdev->constraints->ramp_delay; |
Lee Jones | f3f6439 | 2015-07-09 16:35:28 +0100 | [diff] [blame] | 129 | unsigned int period = pwm_get_period(drvdata->pwm); |
Laxman Dewangan | fd786fb0 | 2016-04-05 15:09:48 +0530 | [diff] [blame^] | 130 | unsigned int req_diff = min_uV - rdev->constraints->min_uV; |
| 131 | unsigned int diff; |
| 132 | unsigned int duty_pulse; |
| 133 | u64 req_period; |
| 134 | u32 rem; |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 135 | int ret; |
| 136 | |
Laxman Dewangan | fd786fb0 | 2016-04-05 15:09:48 +0530 | [diff] [blame^] | 137 | diff = rdev->constraints->max_uV - rdev->constraints->min_uV; |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 138 | |
Laxman Dewangan | fd786fb0 | 2016-04-05 15:09:48 +0530 | [diff] [blame^] | 139 | /* First try to find out if we get the iduty cycle time which is |
| 140 | * factor of PWM period time. If (request_diff_to_min * pwm_period) |
| 141 | * is perfect divided by voltage_range_diff then it is possible to |
| 142 | * get duty cycle time which is factor of PWM period. This will help |
| 143 | * to get output voltage nearer to requested value as there is no |
| 144 | * calculation loss. |
| 145 | */ |
| 146 | req_period = req_diff * period; |
| 147 | div_u64_rem(req_period, diff, &rem); |
| 148 | if (!rem) { |
| 149 | do_div(req_period, diff); |
| 150 | duty_pulse = (unsigned int)req_period; |
| 151 | } else { |
| 152 | duty_pulse = (period / 100) * ((req_diff * 100) / diff); |
| 153 | } |
| 154 | |
| 155 | ret = pwm_config(drvdata->pwm, duty_pulse, period); |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 156 | if (ret) { |
Laxman Dewangan | 5bf59bd | 2016-03-14 18:20:13 +0530 | [diff] [blame] | 157 | dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 158 | return ret; |
| 159 | } |
| 160 | |
| 161 | ret = pwm_enable(drvdata->pwm); |
| 162 | if (ret) { |
Laxman Dewangan | 5bf59bd | 2016-03-14 18:20:13 +0530 | [diff] [blame] | 163 | dev_err(&rdev->dev, "Failed to enable PWM: %d\n", ret); |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 164 | return ret; |
| 165 | } |
| 166 | drvdata->volt_uV = min_uV; |
| 167 | |
| 168 | /* Delay required by PWM regulator to settle to the new voltage */ |
| 169 | usleep_range(ramp_delay, ramp_delay + 1000); |
| 170 | |
| 171 | return 0; |
| 172 | } |
| 173 | |
Lee Jones | f9178da | 2015-07-06 09:58:29 +0100 | [diff] [blame] | 174 | static struct regulator_ops pwm_regulator_voltage_table_ops = { |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 175 | .set_voltage_sel = pwm_regulator_set_voltage_sel, |
| 176 | .get_voltage_sel = pwm_regulator_get_voltage_sel, |
| 177 | .list_voltage = pwm_regulator_list_voltage, |
| 178 | .map_voltage = regulator_map_voltage_iterate, |
Boris Brezillon | 1de7d80 | 2015-09-21 11:33:28 +0200 | [diff] [blame] | 179 | .enable = pwm_regulator_enable, |
| 180 | .disable = pwm_regulator_disable, |
| 181 | .is_enabled = pwm_regulator_is_enabled, |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 182 | }; |
| 183 | |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 184 | static struct regulator_ops pwm_regulator_voltage_continuous_ops = { |
| 185 | .get_voltage = pwm_regulator_get_voltage, |
| 186 | .set_voltage = pwm_regulator_set_voltage, |
Boris Brezillon | 1de7d80 | 2015-09-21 11:33:28 +0200 | [diff] [blame] | 187 | .enable = pwm_regulator_enable, |
| 188 | .disable = pwm_regulator_disable, |
| 189 | .is_enabled = pwm_regulator_is_enabled, |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 190 | }; |
| 191 | |
Lee Jones | b6f55e7 | 2015-06-05 19:42:45 +0100 | [diff] [blame] | 192 | static struct regulator_desc pwm_regulator_desc = { |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 193 | .name = "pwm-regulator", |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 194 | .type = REGULATOR_VOLTAGE, |
| 195 | .owner = THIS_MODULE, |
| 196 | .supply_name = "pwm", |
| 197 | }; |
| 198 | |
Lee Jones | f9178da | 2015-07-06 09:58:29 +0100 | [diff] [blame] | 199 | static int pwm_regulator_init_table(struct platform_device *pdev, |
| 200 | struct pwm_regulator_data *drvdata) |
| 201 | { |
| 202 | struct device_node *np = pdev->dev.of_node; |
| 203 | struct pwm_voltages *duty_cycle_table; |
Lee Jones | 60cb65e | 2015-07-10 08:45:36 +0100 | [diff] [blame] | 204 | unsigned int length = 0; |
Lee Jones | f9178da | 2015-07-06 09:58:29 +0100 | [diff] [blame] | 205 | int ret; |
| 206 | |
| 207 | of_find_property(np, "voltage-table", &length); |
| 208 | |
| 209 | if ((length < sizeof(*duty_cycle_table)) || |
| 210 | (length % sizeof(*duty_cycle_table))) { |
Laxman Dewangan | 5bf59bd | 2016-03-14 18:20:13 +0530 | [diff] [blame] | 211 | dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n", |
Lee Jones | f9178da | 2015-07-06 09:58:29 +0100 | [diff] [blame] | 212 | length); |
| 213 | return -EINVAL; |
| 214 | } |
| 215 | |
| 216 | duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL); |
| 217 | if (!duty_cycle_table) |
| 218 | return -ENOMEM; |
| 219 | |
| 220 | ret = of_property_read_u32_array(np, "voltage-table", |
| 221 | (u32 *)duty_cycle_table, |
| 222 | length / sizeof(u32)); |
| 223 | if (ret) { |
Laxman Dewangan | 5bf59bd | 2016-03-14 18:20:13 +0530 | [diff] [blame] | 224 | dev_err(&pdev->dev, "Failed to read voltage-table: %d\n", ret); |
Lee Jones | f9178da | 2015-07-06 09:58:29 +0100 | [diff] [blame] | 225 | return ret; |
| 226 | } |
| 227 | |
| 228 | drvdata->duty_cycle_table = duty_cycle_table; |
Laxman Dewangan | f907a0a | 2016-03-08 16:23:22 +0530 | [diff] [blame] | 229 | memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops, |
| 230 | sizeof(drvdata->ops)); |
| 231 | drvdata->desc.ops = &drvdata->ops; |
| 232 | drvdata->desc.n_voltages = length / sizeof(*duty_cycle_table); |
Lee Jones | f9178da | 2015-07-06 09:58:29 +0100 | [diff] [blame] | 233 | |
| 234 | return 0; |
| 235 | } |
| 236 | |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 237 | static int pwm_regulator_init_continuous(struct platform_device *pdev, |
| 238 | struct pwm_regulator_data *drvdata) |
| 239 | { |
Laxman Dewangan | f907a0a | 2016-03-08 16:23:22 +0530 | [diff] [blame] | 240 | memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops, |
| 241 | sizeof(drvdata->ops)); |
| 242 | drvdata->desc.ops = &drvdata->ops; |
| 243 | drvdata->desc.continuous_voltage_range = true; |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 244 | |
| 245 | return 0; |
| 246 | } |
| 247 | |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 248 | static int pwm_regulator_probe(struct platform_device *pdev) |
| 249 | { |
Lee Jones | 5ad2cb1 | 2015-07-07 16:06:53 +0100 | [diff] [blame] | 250 | const struct regulator_init_data *init_data; |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 251 | struct pwm_regulator_data *drvdata; |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 252 | struct regulator_dev *regulator; |
| 253 | struct regulator_config config = { }; |
| 254 | struct device_node *np = pdev->dev.of_node; |
Lee Jones | f9178da | 2015-07-06 09:58:29 +0100 | [diff] [blame] | 255 | int ret; |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 256 | |
| 257 | if (!np) { |
| 258 | dev_err(&pdev->dev, "Device Tree node missing\n"); |
| 259 | return -EINVAL; |
| 260 | } |
| 261 | |
| 262 | drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); |
| 263 | if (!drvdata) |
| 264 | return -ENOMEM; |
| 265 | |
Laxman Dewangan | f907a0a | 2016-03-08 16:23:22 +0530 | [diff] [blame] | 266 | memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc)); |
| 267 | |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 268 | if (of_find_property(np, "voltage-table", NULL)) |
Lee Jones | f9178da | 2015-07-06 09:58:29 +0100 | [diff] [blame] | 269 | ret = pwm_regulator_init_table(pdev, drvdata); |
Lee Jones | 4773be1 | 2015-07-07 16:06:51 +0100 | [diff] [blame] | 270 | else |
| 271 | ret = pwm_regulator_init_continuous(pdev, drvdata); |
| 272 | if (ret) |
| 273 | return ret; |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 274 | |
Lee Jones | 5ad2cb1 | 2015-07-07 16:06:53 +0100 | [diff] [blame] | 275 | init_data = of_get_regulator_init_data(&pdev->dev, np, |
Laxman Dewangan | f907a0a | 2016-03-08 16:23:22 +0530 | [diff] [blame] | 276 | &drvdata->desc); |
Lee Jones | 5ad2cb1 | 2015-07-07 16:06:53 +0100 | [diff] [blame] | 277 | if (!init_data) |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 278 | return -ENOMEM; |
| 279 | |
| 280 | config.of_node = np; |
| 281 | config.dev = &pdev->dev; |
| 282 | config.driver_data = drvdata; |
Lee Jones | 5ad2cb1 | 2015-07-07 16:06:53 +0100 | [diff] [blame] | 283 | config.init_data = init_data; |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 284 | |
| 285 | drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); |
| 286 | if (IS_ERR(drvdata->pwm)) { |
Laxman Dewangan | 5bf59bd | 2016-03-14 18:20:13 +0530 | [diff] [blame] | 287 | ret = PTR_ERR(drvdata->pwm); |
| 288 | dev_err(&pdev->dev, "Failed to get PWM: %d\n", ret); |
| 289 | return ret; |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 290 | } |
| 291 | |
| 292 | regulator = devm_regulator_register(&pdev->dev, |
Laxman Dewangan | f907a0a | 2016-03-08 16:23:22 +0530 | [diff] [blame] | 293 | &drvdata->desc, &config); |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 294 | if (IS_ERR(regulator)) { |
Laxman Dewangan | 5bf59bd | 2016-03-14 18:20:13 +0530 | [diff] [blame] | 295 | ret = PTR_ERR(regulator); |
| 296 | dev_err(&pdev->dev, "Failed to register regulator %s: %d\n", |
| 297 | drvdata->desc.name, ret); |
| 298 | return ret; |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 299 | } |
| 300 | |
| 301 | return 0; |
| 302 | } |
| 303 | |
| 304 | static const struct of_device_id pwm_of_match[] = { |
| 305 | { .compatible = "pwm-regulator" }, |
| 306 | { }, |
| 307 | }; |
| 308 | MODULE_DEVICE_TABLE(of, pwm_of_match); |
| 309 | |
| 310 | static struct platform_driver pwm_regulator_driver = { |
| 311 | .driver = { |
| 312 | .name = "pwm-regulator", |
Chris Zhong | aa66cc6 | 2014-09-28 10:28:53 +0800 | [diff] [blame] | 313 | .of_match_table = of_match_ptr(pwm_of_match), |
| 314 | }, |
| 315 | .probe = pwm_regulator_probe, |
| 316 | }; |
| 317 | |
| 318 | module_platform_driver(pwm_regulator_driver); |
| 319 | |
| 320 | MODULE_LICENSE("GPL"); |
| 321 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); |
| 322 | MODULE_DESCRIPTION("PWM Regulator Driver"); |
| 323 | MODULE_ALIAS("platform:pwm-regulator"); |