| 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* |
| 3 | * reg-virtual-consumer.c |
| 4 | * |
| 5 | * Copyright 2008 Wolfson Microelectronics PLC. |
| 6 | * |
| 7 | * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/err.h> |
| 11 | #include <linux/mutex.h> |
| 12 | #include <linux/platform_device.h> |
| 13 | #include <linux/regulator/consumer.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/of.h> |
| 17 | |
| 18 | struct virtual_consumer_data { |
| 19 | struct mutex lock; |
| 20 | struct regulator *regulator; |
| 21 | bool enabled; |
| 22 | int min_uV; |
| 23 | int max_uV; |
| 24 | int min_uA; |
| 25 | int max_uA; |
| 26 | unsigned int mode; |
| 27 | }; |
| 28 | |
| 29 | static void update_voltage_constraints(struct device *dev, |
| 30 | struct virtual_consumer_data *data) |
| 31 | { |
| 32 | int ret; |
| 33 | |
| 34 | if (data->min_uV && data->max_uV |
| 35 | && data->min_uV <= data->max_uV) { |
| 36 | dev_dbg(dev, "Requesting %d-%duV\n", |
| 37 | data->min_uV, data->max_uV); |
| 38 | ret = regulator_set_voltage(data->regulator, |
| 39 | data->min_uV, data->max_uV); |
| 40 | if (ret != 0) { |
| 41 | dev_err(dev, |
| 42 | "regulator_set_voltage() failed: %d\n", ret); |
| 43 | return; |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | if (data->min_uV && data->max_uV && !data->enabled) { |
| 48 | dev_dbg(dev, "Enabling regulator\n"); |
| 49 | ret = regulator_enable(data->regulator); |
| 50 | if (ret == 0) |
| 51 | data->enabled = true; |
| 52 | else |
| 53 | dev_err(dev, "regulator_enable() failed: %d\n", |
| 54 | ret); |
| 55 | } |
| 56 | |
| 57 | if (!(data->min_uV && data->max_uV) && data->enabled) { |
| 58 | dev_dbg(dev, "Disabling regulator\n"); |
| 59 | ret = regulator_disable(data->regulator); |
| 60 | if (ret == 0) |
| 61 | data->enabled = false; |
| 62 | else |
| 63 | dev_err(dev, "regulator_disable() failed: %d\n", |
| 64 | ret); |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | static void update_current_limit_constraints(struct device *dev, |
| 69 | struct virtual_consumer_data *data) |
| 70 | { |
| 71 | int ret; |
| 72 | |
| 73 | if (data->max_uA |
| 74 | && data->min_uA <= data->max_uA) { |
| 75 | dev_dbg(dev, "Requesting %d-%duA\n", |
| 76 | data->min_uA, data->max_uA); |
| 77 | ret = regulator_set_current_limit(data->regulator, |
| 78 | data->min_uA, data->max_uA); |
| 79 | if (ret != 0) { |
| 80 | dev_err(dev, |
| 81 | "regulator_set_current_limit() failed: %d\n", |
| 82 | ret); |
| 83 | return; |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | if (data->max_uA && !data->enabled) { |
| 88 | dev_dbg(dev, "Enabling regulator\n"); |
| 89 | ret = regulator_enable(data->regulator); |
| 90 | if (ret == 0) |
| 91 | data->enabled = true; |
| 92 | else |
| 93 | dev_err(dev, "regulator_enable() failed: %d\n", |
| 94 | ret); |
| 95 | } |
| 96 | |
| 97 | if (!(data->min_uA && data->max_uA) && data->enabled) { |
| 98 | dev_dbg(dev, "Disabling regulator\n"); |
| 99 | ret = regulator_disable(data->regulator); |
| 100 | if (ret == 0) |
| 101 | data->enabled = false; |
| 102 | else |
| 103 | dev_err(dev, "regulator_disable() failed: %d\n", |
| 104 | ret); |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | static ssize_t show_min_uV(struct device *dev, |
| 109 | struct device_attribute *attr, char *buf) |
| 110 | { |
| 111 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 112 | return sprintf(buf, "%d\n", data->min_uV); |
| 113 | } |
| 114 | |
| 115 | static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr, |
| 116 | const char *buf, size_t count) |
| 117 | { |
| 118 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 119 | long val; |
| 120 | |
| 121 | if (kstrtol(buf, 10, &val) != 0) |
| 122 | return count; |
| 123 | |
| 124 | mutex_lock(&data->lock); |
| 125 | |
| 126 | data->min_uV = val; |
| 127 | update_voltage_constraints(dev, data); |
| 128 | |
| 129 | mutex_unlock(&data->lock); |
| 130 | |
| 131 | return count; |
| 132 | } |
| 133 | |
| 134 | static ssize_t show_max_uV(struct device *dev, |
| 135 | struct device_attribute *attr, char *buf) |
| 136 | { |
| 137 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 138 | return sprintf(buf, "%d\n", data->max_uV); |
| 139 | } |
| 140 | |
| 141 | static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr, |
| 142 | const char *buf, size_t count) |
| 143 | { |
| 144 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 145 | long val; |
| 146 | |
| 147 | if (kstrtol(buf, 10, &val) != 0) |
| 148 | return count; |
| 149 | |
| 150 | mutex_lock(&data->lock); |
| 151 | |
| 152 | data->max_uV = val; |
| 153 | update_voltage_constraints(dev, data); |
| 154 | |
| 155 | mutex_unlock(&data->lock); |
| 156 | |
| 157 | return count; |
| 158 | } |
| 159 | |
| 160 | static ssize_t show_min_uA(struct device *dev, |
| 161 | struct device_attribute *attr, char *buf) |
| 162 | { |
| 163 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 164 | return sprintf(buf, "%d\n", data->min_uA); |
| 165 | } |
| 166 | |
| 167 | static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr, |
| 168 | const char *buf, size_t count) |
| 169 | { |
| 170 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 171 | long val; |
| 172 | |
| 173 | if (kstrtol(buf, 10, &val) != 0) |
| 174 | return count; |
| 175 | |
| 176 | mutex_lock(&data->lock); |
| 177 | |
| 178 | data->min_uA = val; |
| 179 | update_current_limit_constraints(dev, data); |
| 180 | |
| 181 | mutex_unlock(&data->lock); |
| 182 | |
| 183 | return count; |
| 184 | } |
| 185 | |
| 186 | static ssize_t show_max_uA(struct device *dev, |
| 187 | struct device_attribute *attr, char *buf) |
| 188 | { |
| 189 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 190 | return sprintf(buf, "%d\n", data->max_uA); |
| 191 | } |
| 192 | |
| 193 | static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr, |
| 194 | const char *buf, size_t count) |
| 195 | { |
| 196 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 197 | long val; |
| 198 | |
| 199 | if (kstrtol(buf, 10, &val) != 0) |
| 200 | return count; |
| 201 | |
| 202 | mutex_lock(&data->lock); |
| 203 | |
| 204 | data->max_uA = val; |
| 205 | update_current_limit_constraints(dev, data); |
| 206 | |
| 207 | mutex_unlock(&data->lock); |
| 208 | |
| 209 | return count; |
| 210 | } |
| 211 | |
| 212 | static ssize_t show_mode(struct device *dev, |
| 213 | struct device_attribute *attr, char *buf) |
| 214 | { |
| 215 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 216 | |
| 217 | switch (data->mode) { |
| 218 | case REGULATOR_MODE_FAST: |
| 219 | return sprintf(buf, "fast\n"); |
| 220 | case REGULATOR_MODE_NORMAL: |
| 221 | return sprintf(buf, "normal\n"); |
| 222 | case REGULATOR_MODE_IDLE: |
| 223 | return sprintf(buf, "idle\n"); |
| 224 | case REGULATOR_MODE_STANDBY: |
| 225 | return sprintf(buf, "standby\n"); |
| 226 | default: |
| 227 | return sprintf(buf, "unknown\n"); |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | static ssize_t set_mode(struct device *dev, struct device_attribute *attr, |
| 232 | const char *buf, size_t count) |
| 233 | { |
| 234 | struct virtual_consumer_data *data = dev_get_drvdata(dev); |
| 235 | unsigned int mode; |
| 236 | int ret; |
| 237 | |
| 238 | /* |
| 239 | * sysfs_streq() doesn't need the \n's, but we add them so the strings |
| 240 | * will be shared with show_mode(), above. |
| 241 | */ |
| 242 | if (sysfs_streq(buf, "fast\n")) |
| 243 | mode = REGULATOR_MODE_FAST; |
| 244 | else if (sysfs_streq(buf, "normal\n")) |
| 245 | mode = REGULATOR_MODE_NORMAL; |
| 246 | else if (sysfs_streq(buf, "idle\n")) |
| 247 | mode = REGULATOR_MODE_IDLE; |
| 248 | else if (sysfs_streq(buf, "standby\n")) |
| 249 | mode = REGULATOR_MODE_STANDBY; |
| 250 | else { |
| 251 | dev_err(dev, "Configuring invalid mode\n"); |
| 252 | return count; |
| 253 | } |
| 254 | |
| 255 | mutex_lock(&data->lock); |
| 256 | ret = regulator_set_mode(data->regulator, mode); |
| 257 | if (ret == 0) |
| 258 | data->mode = mode; |
| 259 | else |
| 260 | dev_err(dev, "Failed to configure mode: %d\n", ret); |
| 261 | mutex_unlock(&data->lock); |
| 262 | |
| 263 | return count; |
| 264 | } |
| 265 | |
| 266 | static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV); |
| 267 | static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV); |
| 268 | static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA); |
| 269 | static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA); |
| 270 | static DEVICE_ATTR(mode, 0664, show_mode, set_mode); |
| 271 | |
| 272 | static struct attribute *regulator_virtual_attributes[] = { |
| 273 | &dev_attr_min_microvolts.attr, |
| 274 | &dev_attr_max_microvolts.attr, |
| 275 | &dev_attr_min_microamps.attr, |
| 276 | &dev_attr_max_microamps.attr, |
| 277 | &dev_attr_mode.attr, |
| 278 | NULL |
| 279 | }; |
| 280 | |
| 281 | static const struct attribute_group regulator_virtual_attr_group = { |
| 282 | .attrs = regulator_virtual_attributes, |
| 283 | }; |
| 284 | |
| 285 | #ifdef CONFIG_OF |
| 286 | static const struct of_device_id regulator_virtual_consumer_of_match[] = { |
| 287 | { .compatible = "regulator-virtual-consumer" }, |
| 288 | {}, |
| 289 | }; |
| 290 | MODULE_DEVICE_TABLE(of, regulator_virtual_consumer_of_match); |
| 291 | #endif |
| 292 | |
| 293 | static int regulator_virtual_probe(struct platform_device *pdev) |
| 294 | { |
| 295 | char *reg_id = dev_get_platdata(&pdev->dev); |
| 296 | struct virtual_consumer_data *drvdata; |
| 297 | static bool warned; |
| 298 | int ret; |
| 299 | |
| 300 | if (!warned) { |
| 301 | warned = true; |
| 302 | pr_warn("**********************************************************\n"); |
| 303 | pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); |
| 304 | pr_warn("** **\n"); |
| 305 | pr_warn("** regulator-virtual-consumer is only for testing and **\n"); |
| 306 | pr_warn("** debugging. Do not use it in a production kernel. **\n"); |
| 307 | pr_warn("** **\n"); |
| 308 | pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); |
| 309 | pr_warn("**********************************************************\n"); |
| 310 | } |
| 311 | |
| 312 | drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data), |
| 313 | GFP_KERNEL); |
| 314 | if (drvdata == NULL) |
| 315 | return -ENOMEM; |
| 316 | |
| 317 | /* |
| 318 | * This virtual consumer does not have any hardware-defined supply |
| 319 | * name, so just allow the regulator to be specified in a property |
| 320 | * named "default-supply" when we're being probed from devicetree. |
| 321 | */ |
| 322 | if (!reg_id && pdev->dev.of_node) |
| 323 | reg_id = "default"; |
| 324 | |
| 325 | mutex_init(&drvdata->lock); |
| 326 | |
| 327 | drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id); |
| 328 | if (IS_ERR(drvdata->regulator)) |
| 329 | return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->regulator), |
| 330 | "Failed to obtain supply '%s'\n", |
| 331 | reg_id); |
| 332 | |
| 333 | ret = sysfs_create_group(&pdev->dev.kobj, |
| 334 | ®ulator_virtual_attr_group); |
| 335 | if (ret != 0) { |
| 336 | dev_err(&pdev->dev, |
| 337 | "Failed to create attribute group: %d\n", ret); |
| 338 | return ret; |
| 339 | } |
| 340 | |
| 341 | drvdata->mode = regulator_get_mode(drvdata->regulator); |
| 342 | |
| 343 | platform_set_drvdata(pdev, drvdata); |
| 344 | |
| 345 | return 0; |
| 346 | } |
| 347 | |
| 348 | static int regulator_virtual_remove(struct platform_device *pdev) |
| 349 | { |
| 350 | struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev); |
| 351 | |
| 352 | sysfs_remove_group(&pdev->dev.kobj, ®ulator_virtual_attr_group); |
| 353 | |
| 354 | if (drvdata->enabled) |
| 355 | regulator_disable(drvdata->regulator); |
| 356 | |
| 357 | return 0; |
| 358 | } |
| 359 | |
| 360 | static struct platform_driver regulator_virtual_consumer_driver = { |
| 361 | .probe = regulator_virtual_probe, |
| 362 | .remove = regulator_virtual_remove, |
| 363 | .driver = { |
| 364 | .name = "reg-virt-consumer", |
| 365 | .of_match_table = of_match_ptr(regulator_virtual_consumer_of_match), |
| 366 | }, |
| 367 | }; |
| 368 | |
| 369 | module_platform_driver(regulator_virtual_consumer_driver); |
| 370 | |
| 371 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); |
| 372 | MODULE_DESCRIPTION("Virtual regulator consumer"); |
| 373 | MODULE_LICENSE("GPL"); |
| 374 | MODULE_ALIAS("platform:reg-virt-consumer"); |