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 #include <linux/slab.h> 19 #include <linux/module.h> 20 21 struct virtual_consumer_data { 22 struct mutex lock; 23 struct regulator *regulator; 24 bool enabled; 25 int min_uV; 26 int max_uV; 27 int min_uA; 28 int max_uA; 29 unsigned int mode; 30 }; 31 32 static void update_voltage_constraints(struct device *dev, 33 struct virtual_consumer_data *data) 34 { 35 int ret; 36 37 if (data->min_uV && data->max_uV 38 && data->min_uV <= data->max_uV) { 39 dev_dbg(dev, "Requesting %d-%duV\n", 40 data->min_uV, data->max_uV); 41 ret = regulator_set_voltage(data->regulator, 42 data->min_uV, data->max_uV); 43 if (ret != 0) { 44 dev_err(dev, 45 "regulator_set_voltage() failed: %d\n", ret); 46 return; 47 } 48 } 49 50 if (data->min_uV && data->max_uV && !data->enabled) { 51 dev_dbg(dev, "Enabling regulator\n"); 52 ret = regulator_enable(data->regulator); 53 if (ret == 0) 54 data->enabled = true; 55 else 56 dev_err(dev, "regulator_enable() failed: %d\n", 57 ret); 58 } 59 60 if (!(data->min_uV && data->max_uV) && data->enabled) { 61 dev_dbg(dev, "Disabling regulator\n"); 62 ret = regulator_disable(data->regulator); 63 if (ret == 0) 64 data->enabled = false; 65 else 66 dev_err(dev, "regulator_disable() failed: %d\n", 67 ret); 68 } 69 } 70 71 static void update_current_limit_constraints(struct device *dev, 72 struct virtual_consumer_data *data) 73 { 74 int ret; 75 76 if (data->max_uA 77 && data->min_uA <= data->max_uA) { 78 dev_dbg(dev, "Requesting %d-%duA\n", 79 data->min_uA, data->max_uA); 80 ret = regulator_set_current_limit(data->regulator, 81 data->min_uA, data->max_uA); 82 if (ret != 0) { 83 dev_err(dev, 84 "regulator_set_current_limit() failed: %d\n", 85 ret); 86 return; 87 } 88 } 89 90 if (data->max_uA && !data->enabled) { 91 dev_dbg(dev, "Enabling regulator\n"); 92 ret = regulator_enable(data->regulator); 93 if (ret == 0) 94 data->enabled = true; 95 else 96 dev_err(dev, "regulator_enable() failed: %d\n", 97 ret); 98 } 99 100 if (!(data->min_uA && data->max_uA) && data->enabled) { 101 dev_dbg(dev, "Disabling regulator\n"); 102 ret = regulator_disable(data->regulator); 103 if (ret == 0) 104 data->enabled = false; 105 else 106 dev_err(dev, "regulator_disable() failed: %d\n", 107 ret); 108 } 109 } 110 111 static ssize_t show_min_uV(struct device *dev, 112 struct device_attribute *attr, char *buf) 113 { 114 struct virtual_consumer_data *data = dev_get_drvdata(dev); 115 return sprintf(buf, "%d\n", data->min_uV); 116 } 117 118 static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr, 119 const char *buf, size_t count) 120 { 121 struct virtual_consumer_data *data = dev_get_drvdata(dev); 122 long val; 123 124 if (kstrtol(buf, 10, &val) != 0) 125 return count; 126 127 mutex_lock(&data->lock); 128 129 data->min_uV = val; 130 update_voltage_constraints(dev, data); 131 132 mutex_unlock(&data->lock); 133 134 return count; 135 } 136 137 static ssize_t show_max_uV(struct device *dev, 138 struct device_attribute *attr, char *buf) 139 { 140 struct virtual_consumer_data *data = dev_get_drvdata(dev); 141 return sprintf(buf, "%d\n", data->max_uV); 142 } 143 144 static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr, 145 const char *buf, size_t count) 146 { 147 struct virtual_consumer_data *data = dev_get_drvdata(dev); 148 long val; 149 150 if (kstrtol(buf, 10, &val) != 0) 151 return count; 152 153 mutex_lock(&data->lock); 154 155 data->max_uV = val; 156 update_voltage_constraints(dev, data); 157 158 mutex_unlock(&data->lock); 159 160 return count; 161 } 162 163 static ssize_t show_min_uA(struct device *dev, 164 struct device_attribute *attr, char *buf) 165 { 166 struct virtual_consumer_data *data = dev_get_drvdata(dev); 167 return sprintf(buf, "%d\n", data->min_uA); 168 } 169 170 static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr, 171 const char *buf, size_t count) 172 { 173 struct virtual_consumer_data *data = dev_get_drvdata(dev); 174 long val; 175 176 if (kstrtol(buf, 10, &val) != 0) 177 return count; 178 179 mutex_lock(&data->lock); 180 181 data->min_uA = val; 182 update_current_limit_constraints(dev, data); 183 184 mutex_unlock(&data->lock); 185 186 return count; 187 } 188 189 static ssize_t show_max_uA(struct device *dev, 190 struct device_attribute *attr, char *buf) 191 { 192 struct virtual_consumer_data *data = dev_get_drvdata(dev); 193 return sprintf(buf, "%d\n", data->max_uA); 194 } 195 196 static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr, 197 const char *buf, size_t count) 198 { 199 struct virtual_consumer_data *data = dev_get_drvdata(dev); 200 long val; 201 202 if (kstrtol(buf, 10, &val) != 0) 203 return count; 204 205 mutex_lock(&data->lock); 206 207 data->max_uA = val; 208 update_current_limit_constraints(dev, data); 209 210 mutex_unlock(&data->lock); 211 212 return count; 213 } 214 215 static ssize_t show_mode(struct device *dev, 216 struct device_attribute *attr, char *buf) 217 { 218 struct virtual_consumer_data *data = dev_get_drvdata(dev); 219 220 switch (data->mode) { 221 case REGULATOR_MODE_FAST: 222 return sprintf(buf, "fast\n"); 223 case REGULATOR_MODE_NORMAL: 224 return sprintf(buf, "normal\n"); 225 case REGULATOR_MODE_IDLE: 226 return sprintf(buf, "idle\n"); 227 case REGULATOR_MODE_STANDBY: 228 return sprintf(buf, "standby\n"); 229 default: 230 return sprintf(buf, "unknown\n"); 231 } 232 } 233 234 static ssize_t set_mode(struct device *dev, struct device_attribute *attr, 235 const char *buf, size_t count) 236 { 237 struct virtual_consumer_data *data = dev_get_drvdata(dev); 238 unsigned int mode; 239 int ret; 240 241 /* 242 * sysfs_streq() doesn't need the \n's, but we add them so the strings 243 * will be shared with show_mode(), above. 244 */ 245 if (sysfs_streq(buf, "fast\n")) 246 mode = REGULATOR_MODE_FAST; 247 else if (sysfs_streq(buf, "normal\n")) 248 mode = REGULATOR_MODE_NORMAL; 249 else if (sysfs_streq(buf, "idle\n")) 250 mode = REGULATOR_MODE_IDLE; 251 else if (sysfs_streq(buf, "standby\n")) 252 mode = REGULATOR_MODE_STANDBY; 253 else { 254 dev_err(dev, "Configuring invalid mode\n"); 255 return count; 256 } 257 258 mutex_lock(&data->lock); 259 ret = regulator_set_mode(data->regulator, mode); 260 if (ret == 0) 261 data->mode = mode; 262 else 263 dev_err(dev, "Failed to configure mode: %d\n", ret); 264 mutex_unlock(&data->lock); 265 266 return count; 267 } 268 269 static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV); 270 static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV); 271 static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA); 272 static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA); 273 static DEVICE_ATTR(mode, 0664, show_mode, set_mode); 274 275 static struct attribute *regulator_virtual_attributes[] = { 276 &dev_attr_min_microvolts.attr, 277 &dev_attr_max_microvolts.attr, 278 &dev_attr_min_microamps.attr, 279 &dev_attr_max_microamps.attr, 280 &dev_attr_mode.attr, 281 NULL 282 }; 283 284 static const struct attribute_group regulator_virtual_attr_group = { 285 .attrs = regulator_virtual_attributes, 286 }; 287 288 static int regulator_virtual_probe(struct platform_device *pdev) 289 { 290 char *reg_id = dev_get_platdata(&pdev->dev); 291 struct virtual_consumer_data *drvdata; 292 int ret; 293 294 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data), 295 GFP_KERNEL); 296 if (drvdata == NULL) 297 return -ENOMEM; 298 299 mutex_init(&drvdata->lock); 300 301 drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id); 302 if (IS_ERR(drvdata->regulator)) { 303 ret = PTR_ERR(drvdata->regulator); 304 dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n", 305 reg_id, ret); 306 return ret; 307 } 308 309 ret = sysfs_create_group(&pdev->dev.kobj, 310 ®ulator_virtual_attr_group); 311 if (ret != 0) { 312 dev_err(&pdev->dev, 313 "Failed to create attribute group: %d\n", ret); 314 return ret; 315 } 316 317 drvdata->mode = regulator_get_mode(drvdata->regulator); 318 319 platform_set_drvdata(pdev, drvdata); 320 321 return 0; 322 } 323 324 static int regulator_virtual_remove(struct platform_device *pdev) 325 { 326 struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev); 327 328 sysfs_remove_group(&pdev->dev.kobj, ®ulator_virtual_attr_group); 329 330 if (drvdata->enabled) 331 regulator_disable(drvdata->regulator); 332 333 return 0; 334 } 335 336 static struct platform_driver regulator_virtual_consumer_driver = { 337 .probe = regulator_virtual_probe, 338 .remove = regulator_virtual_remove, 339 .driver = { 340 .name = "reg-virt-consumer", 341 }, 342 }; 343 344 module_platform_driver(regulator_virtual_consumer_driver); 345 346 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 347 MODULE_DESCRIPTION("Virtual regulator consumer"); 348 MODULE_LICENSE("GPL"); 349 MODULE_ALIAS("platform:reg-virt-consumer"); 350