| 1 | /* |
| 2 | * reg-virtual-consumer.c |
| 3 | * |
| 4 | * Copyright 2008 Wolfson Microelectronics PLC. |
| 5 | * |
| 6 | * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of the |
| 11 | * License, or (at your option) any later version. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/err.h> |
| 15 | #include <linux/mutex.h> |
| 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/regulator/consumer.h> |
| 18 | |
| 19 | struct virtual_consumer_data { |
| 20 | struct mutex lock; |
| 21 | struct regulator *regulator; |
| 22 | int enabled; |
| 23 | int min_uV; |
| 24 | int max_uV; |
| 25 | int min_uA; |
| 26 | int max_uA; |
| 27 | unsigned int mode; |
| 28 | }; |
| 29 | |
| 30 | static void update_voltage_constraints(struct device *dev, |
| 31 | struct virtual_consumer_data *data) |
| 32 | { |
| 33 | int ret; |
| 34 | |
| 35 | if (data->min_uV && data->max_uV |
| 36 | && data->min_uV <= data->max_uV) { |
| 37 | dev_dbg(dev, "Requesting %d-%duV\n", |
| 38 | data->min_uV, data->max_uV); |
| 39 | ret = regulator_set_voltage(data->regulator, |
| 40 | data->min_uV, data->max_uV); |
| 41 | if (ret != 0) { |
| 42 | dev_err(dev, |
| 43 | "regulator_set_voltage() failed: %d\n", ret); |
| 44 | return; |
| 45 | } |
| 46 | } |
| 47 | |
| 48 | if (data->min_uV && data->max_uV && !data->enabled) { |
| 49 | dev_dbg(dev, "Enabling regulator\n"); |
| 50 | ret = regulator_enable(data->regulator); |
| 51 | if (ret == 0) |
| 52 | data->enabled = 1; |
| 53 | else |
| 54 | dev_err(dev, "regulator_enable() failed: %d\n", |
| 55 | ret); |
| 56 | } |
| 57 | |
| 58 | if (!(data->min_uV && data->max_uV) && data->enabled) { |
| 59 | dev_dbg(dev, "Disabling regulator\n"); |
| 60 | ret = regulator_disable(data->regulator); |
| 61 | if (ret == 0) |
| 62 | data->enabled = 0; |
| 63 | else |
| 64 | dev_err(dev, "regulator_disable() failed: %d\n", |
| 65 | ret); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | static void update_current_limit_constraints(struct device *dev, |
| 70 | struct virtual_consumer_data *data) |
| 71 | { |
| 72 | int ret; |
| 73 | |
| 74 | if (data->max_uA |
| 75 | && data->min_uA <= data->max_uA) { |
| 76 | dev_dbg(dev, "Requesting %d-%duA\n", |
| 77 | data->min_uA, data->max_uA); |
| 78 | ret = regulator_set_current_limit(data->regulator, |
| 79 | data->min_uA, data->max_uA); |
| 80 | if (ret != 0) { |
| 81 | dev_err(dev, |
| 82 | "regulator_set_current_limit() failed: %d\n", |
| 83 | ret); |
| 84 | return; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | if (data->max_uA && !data->enabled) { |
| 89 | dev_dbg(dev, "Enabling regulator\n"); |
| 90 | ret = regulator_enable(data->regulator); |
| 91 | if (ret == 0) |
| 92 | data->enabled = 1; |
| 93 | else |
| 94 | dev_err(dev, "regulator_enable() failed: %d\n", |
| 95 | ret); |
| 96 | } |
| 97 | |
| 98 | if (!(data->min_uA && data->max_uA) && data->enabled) { |
| 99 | dev_dbg(dev, "Disabling regulator\n"); |
| 100 | ret = regulator_disable(data->regulator); |
| 101 | if (ret == 0) |
| 102 | data->enabled = 0; |
| 103 | else |
| 104 | dev_err(dev, "regulator_disable() failed: %d\n", |
| 105 | ret); |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | static ssize_t show_min_uV(struct device *dev, |
| 110 | struct device_attribute *attr, char *buf) |
| 111 | { |
| 112 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 113 | return sprintf(buf, "%d\n", data->min_uV); |
| 114 | } |
| 115 | |
| 116 | static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr, |
| 117 | const char *buf, size_t count) |
| 118 | { |
| 119 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 120 | long val; |
| 121 | |
| 122 | if (strict_strtol(buf, 10, &val) != 0) |
| 123 | return count; |
| 124 | |
| 125 | mutex_lock(&data->lock); |
| 126 | |
| 127 | data->min_uV = val; |
| 128 | update_voltage_constraints(dev, data); |
| 129 | |
| 130 | mutex_unlock(&data->lock); |
| 131 | |
| 132 | return count; |
| 133 | } |
| 134 | |
| 135 | static ssize_t show_max_uV(struct device *dev, |
| 136 | struct device_attribute *attr, char *buf) |
| 137 | { |
| 138 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 139 | return sprintf(buf, "%d\n", data->max_uV); |
| 140 | } |
| 141 | |
| 142 | static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr, |
| 143 | const char *buf, size_t count) |
| 144 | { |
| 145 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 146 | long val; |
| 147 | |
| 148 | if (strict_strtol(buf, 10, &val) != 0) |
| 149 | return count; |
| 150 | |
| 151 | mutex_lock(&data->lock); |
| 152 | |
| 153 | data->max_uV = val; |
| 154 | update_voltage_constraints(dev, data); |
| 155 | |
| 156 | mutex_unlock(&data->lock); |
| 157 | |
| 158 | return count; |
| 159 | } |
| 160 | |
| 161 | static ssize_t show_min_uA(struct device *dev, |
| 162 | struct device_attribute *attr, char *buf) |
| 163 | { |
| 164 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 165 | return sprintf(buf, "%d\n", data->min_uA); |
| 166 | } |
| 167 | |
| 168 | static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr, |
| 169 | const char *buf, size_t count) |
| 170 | { |
| 171 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 172 | long val; |
| 173 | |
| 174 | if (strict_strtol(buf, 10, &val) != 0) |
| 175 | return count; |
| 176 | |
| 177 | mutex_lock(&data->lock); |
| 178 | |
| 179 | data->min_uA = val; |
| 180 | update_current_limit_constraints(dev, data); |
| 181 | |
| 182 | mutex_unlock(&data->lock); |
| 183 | |
| 184 | return count; |
| 185 | } |
| 186 | |
| 187 | static ssize_t show_max_uA(struct device *dev, |
| 188 | struct device_attribute *attr, char *buf) |
| 189 | { |
| 190 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 191 | return sprintf(buf, "%d\n", data->max_uA); |
| 192 | } |
| 193 | |
| 194 | static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr, |
| 195 | const char *buf, size_t count) |
| 196 | { |
| 197 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 198 | long val; |
| 199 | |
| 200 | if (strict_strtol(buf, 10, &val) != 0) |
| 201 | return count; |
| 202 | |
| 203 | mutex_lock(&data->lock); |
| 204 | |
| 205 | data->max_uA = val; |
| 206 | update_current_limit_constraints(dev, data); |
| 207 | |
| 208 | mutex_unlock(&data->lock); |
| 209 | |
| 210 | return count; |
| 211 | } |
| 212 | |
| 213 | static ssize_t show_mode(struct device *dev, |
| 214 | struct device_attribute *attr, char *buf) |
| 215 | { |
| 216 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 217 | |
| 218 | switch (data->mode) { |
| 219 | case REGULATOR_MODE_FAST: |
| 220 | return sprintf(buf, "fast\n"); |
| 221 | case REGULATOR_MODE_NORMAL: |
| 222 | return sprintf(buf, "normal\n"); |
| 223 | case REGULATOR_MODE_IDLE: |
| 224 | return sprintf(buf, "idle\n"); |
| 225 | case REGULATOR_MODE_STANDBY: |
| 226 | return sprintf(buf, "standby\n"); |
| 227 | default: |
| 228 | return sprintf(buf, "unknown\n"); |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | static ssize_t set_mode(struct device *dev, struct device_attribute *attr, |
| 233 | const char *buf, size_t count) |
| 234 | { |
| 235 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 236 | unsigned int mode; |
| 237 | int ret; |
| 238 | |
| 239 | /* |
| 240 | * sysfs_streq() doesn't need the \n's, but we add them so the strings |
| 241 | * will be shared with show_mode(), above. |
| 242 | */ |
| 243 | if (sysfs_streq(buf, "fast\n")) |
| 244 | mode = REGULATOR_MODE_FAST; |
| 245 | else if (sysfs_streq(buf, "normal\n")) |
| 246 | mode = REGULATOR_MODE_NORMAL; |
| 247 | else if (sysfs_streq(buf, "idle\n")) |
| 248 | mode = REGULATOR_MODE_IDLE; |
| 249 | else if (sysfs_streq(buf, "standby\n")) |
| 250 | mode = REGULATOR_MODE_STANDBY; |
| 251 | else { |
| 252 | dev_err(dev, "Configuring invalid mode\n"); |
| 253 | return count; |
| 254 | } |
| 255 | |
| 256 | mutex_lock(&data->lock); |
| 257 | ret = regulator_set_mode(data->regulator, mode); |
| 258 | if (ret == 0) |
| 259 | data->mode = mode; |
| 260 | else |
| 261 | dev_err(dev, "Failed to configure mode: %d\n", ret); |
| 262 | mutex_unlock(&data->lock); |
| 263 | |
| 264 | return count; |
| 265 | } |
| 266 | |
| 267 | static DEVICE_ATTR(min_microvolts, 0666, show_min_uV, set_min_uV); |
| 268 | static DEVICE_ATTR(max_microvolts, 0666, show_max_uV, set_max_uV); |
| 269 | static DEVICE_ATTR(min_microamps, 0666, show_min_uA, set_min_uA); |
| 270 | static DEVICE_ATTR(max_microamps, 0666, show_max_uA, set_max_uA); |
| 271 | static DEVICE_ATTR(mode, 0666, show_mode, set_mode); |
| 272 | |
| 273 | static struct device_attribute *attributes[] = { |
| 274 | &dev_attr_min_microvolts, |
| 275 | &dev_attr_max_microvolts, |
| 276 | &dev_attr_min_microamps, |
| 277 | &dev_attr_max_microamps, |
| 278 | &dev_attr_mode, |
| 279 | }; |
| 280 | |
| 281 | static int regulator_virtual_consumer_probe(struct platform_device *pdev) |
| 282 | { |
| 283 | char *reg_id = pdev->dev.platform_data; |
| 284 | struct virtual_consumer_data *drvdata; |
| 285 | int ret, i; |
| 286 | |
| 287 | drvdata = kzalloc(sizeof(struct virtual_consumer_data), GFP_KERNEL); |
| 288 | if (drvdata == NULL) { |
| 289 | return -ENOMEM; |
| 290 | } |
| 291 | |
| 292 | mutex_init(&drvdata->lock); |
| 293 | |
| 294 | drvdata->regulator = regulator_get(&pdev->dev, reg_id); |
| 295 | if (IS_ERR(drvdata->regulator)) { |
| 296 | ret = PTR_ERR(drvdata->regulator); |
| 297 | dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n", |
| 298 | reg_id, ret); |
| 299 | goto err; |
| 300 | } |
| 301 | |
| 302 | for (i = 0; i < ARRAY_SIZE(attributes); i++) { |
| 303 | ret = device_create_file(&pdev->dev, attributes[i]); |
| 304 | if (ret != 0) { |
| 305 | dev_err(&pdev->dev, "Failed to create attr %d: %d\n", |
| 306 | i, ret); |
| 307 | goto err_regulator; |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | drvdata->mode = regulator_get_mode(drvdata->regulator); |
| 312 | |
| 313 | platform_set_drvdata(pdev, drvdata); |
| 314 | |
| 315 | return 0; |
| 316 | |
| 317 | err_regulator: |
| 318 | regulator_put(drvdata->regulator); |
| 319 | err: |
| 320 | for (i = 0; i < ARRAY_SIZE(attributes); i++) |
| 321 | device_remove_file(&pdev->dev, attributes[i]); |
| 322 | kfree(drvdata); |
| 323 | return ret; |
| 324 | } |
| 325 | |
| 326 | static int regulator_virtual_consumer_remove(struct platform_device *pdev) |
| 327 | { |
| 328 | struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev); |
| 329 | int i; |
| 330 | |
| 331 | for (i = 0; i < ARRAY_SIZE(attributes); i++) |
| 332 | device_remove_file(&pdev->dev, attributes[i]); |
| 333 | if (drvdata->enabled) |
| 334 | regulator_disable(drvdata->regulator); |
| 335 | regulator_put(drvdata->regulator); |
| 336 | |
| 337 | kfree(drvdata); |
| 338 | |
| 339 | return 0; |
| 340 | } |
| 341 | |
| 342 | static struct platform_driver regulator_virtual_consumer_driver = { |
| 343 | .probe = regulator_virtual_consumer_probe, |
| 344 | .remove = regulator_virtual_consumer_remove, |
| 345 | .driver = { |
| 346 | .name = "reg-virt-consumer", |
| 347 | }, |
| 348 | }; |
| 349 | |
| 350 | |
| 351 | static int __init regulator_virtual_consumer_init(void) |
| 352 | { |
| 353 | return platform_driver_register(®ulator_virtual_consumer_driver); |
| 354 | } |
| 355 | module_init(regulator_virtual_consumer_init); |
| 356 | |
| 357 | static void __exit regulator_virtual_consumer_exit(void) |
| 358 | { |
| 359 | platform_driver_unregister(®ulator_virtual_consumer_driver); |
| 360 | } |
| 361 | module_exit(regulator_virtual_consumer_exit); |
| 362 | |
| 363 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); |
| 364 | MODULE_DESCRIPTION("Virtual regulator consumer"); |
| 365 | MODULE_LICENSE("GPL"); |
| 366 | MODULE_ALIAS("platform:reg-virt-consumer"); |