1 /* 2 * gpio-regulator.c 3 * 4 * Copyright 2011 Heiko Stuebner <heiko@sntech.de> 5 * 6 * based on fixed.c 7 * 8 * Copyright 2008 Wolfson Microelectronics PLC. 9 * 10 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 11 * 12 * Copyright (c) 2009 Nokia Corporation 13 * Roger Quadros <ext-roger.quadros@nokia.com> 14 * 15 * This program is free software; you can redistribute it and/or 16 * modify it under the terms of the GNU General Public License as 17 * published by the Free Software Foundation; either version 2 of the 18 * License, or (at your option) any later version. 19 * 20 * This is useful for systems with mixed controllable and 21 * non-controllable regulators, as well as for allowing testing on 22 * systems with no controllable regulators. 23 */ 24 25 #include <linux/err.h> 26 #include <linux/mutex.h> 27 #include <linux/module.h> 28 #include <linux/platform_device.h> 29 #include <linux/regulator/driver.h> 30 #include <linux/regulator/machine.h> 31 #include <linux/regulator/of_regulator.h> 32 #include <linux/regulator/gpio-regulator.h> 33 #include <linux/gpio.h> 34 #include <linux/slab.h> 35 #include <linux/of.h> 36 #include <linux/of_gpio.h> 37 38 struct gpio_regulator_data { 39 struct regulator_desc desc; 40 struct regulator_dev *dev; 41 42 struct gpio *gpios; 43 int nr_gpios; 44 45 struct gpio_regulator_state *states; 46 int nr_states; 47 48 int state; 49 }; 50 51 static int gpio_regulator_get_value(struct regulator_dev *dev) 52 { 53 struct gpio_regulator_data *data = rdev_get_drvdata(dev); 54 int ptr; 55 56 for (ptr = 0; ptr < data->nr_states; ptr++) 57 if (data->states[ptr].gpios == data->state) 58 return data->states[ptr].value; 59 60 return -EINVAL; 61 } 62 63 static int gpio_regulator_set_voltage(struct regulator_dev *dev, 64 int min_uV, int max_uV, 65 unsigned *selector) 66 { 67 struct gpio_regulator_data *data = rdev_get_drvdata(dev); 68 int ptr, target = 0, state, best_val = INT_MAX; 69 70 for (ptr = 0; ptr < data->nr_states; ptr++) 71 if (data->states[ptr].value < best_val && 72 data->states[ptr].value >= min_uV && 73 data->states[ptr].value <= max_uV) { 74 target = data->states[ptr].gpios; 75 best_val = data->states[ptr].value; 76 if (selector) 77 *selector = ptr; 78 } 79 80 if (best_val == INT_MAX) 81 return -EINVAL; 82 83 for (ptr = 0; ptr < data->nr_gpios; ptr++) { 84 state = (target & (1 << ptr)) >> ptr; 85 gpio_set_value_cansleep(data->gpios[ptr].gpio, state); 86 } 87 data->state = target; 88 89 return 0; 90 } 91 92 static int gpio_regulator_list_voltage(struct regulator_dev *dev, 93 unsigned selector) 94 { 95 struct gpio_regulator_data *data = rdev_get_drvdata(dev); 96 97 if (selector >= data->nr_states) 98 return -EINVAL; 99 100 return data->states[selector].value; 101 } 102 103 static int gpio_regulator_set_current_limit(struct regulator_dev *dev, 104 int min_uA, int max_uA) 105 { 106 struct gpio_regulator_data *data = rdev_get_drvdata(dev); 107 int ptr, target = 0, state, best_val = 0; 108 109 for (ptr = 0; ptr < data->nr_states; ptr++) 110 if (data->states[ptr].value > best_val && 111 data->states[ptr].value >= min_uA && 112 data->states[ptr].value <= max_uA) { 113 target = data->states[ptr].gpios; 114 best_val = data->states[ptr].value; 115 } 116 117 if (best_val == 0) 118 return -EINVAL; 119 120 for (ptr = 0; ptr < data->nr_gpios; ptr++) { 121 state = (target & (1 << ptr)) >> ptr; 122 gpio_set_value_cansleep(data->gpios[ptr].gpio, state); 123 } 124 data->state = target; 125 126 return 0; 127 } 128 129 static struct regulator_ops gpio_regulator_voltage_ops = { 130 .get_voltage = gpio_regulator_get_value, 131 .set_voltage = gpio_regulator_set_voltage, 132 .list_voltage = gpio_regulator_list_voltage, 133 }; 134 135 struct gpio_regulator_config * 136 of_get_gpio_regulator_config(struct device *dev, struct device_node *np) 137 { 138 struct gpio_regulator_config *config; 139 struct property *prop; 140 const char *regtype; 141 int proplen, gpio, i; 142 143 config = devm_kzalloc(dev, 144 sizeof(struct gpio_regulator_config), 145 GFP_KERNEL); 146 if (!config) 147 return ERR_PTR(-ENOMEM); 148 149 config->init_data = of_get_regulator_init_data(dev, np); 150 if (!config->init_data) 151 return ERR_PTR(-EINVAL); 152 153 config->supply_name = config->init_data->constraints.name; 154 155 if (of_property_read_bool(np, "enable-active-high")) 156 config->enable_high = true; 157 158 if (of_property_read_bool(np, "enable-at-boot")) 159 config->enabled_at_boot = true; 160 161 of_property_read_u32(np, "startup-delay-us", &config->startup_delay); 162 163 config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0); 164 165 /* Fetch GPIOs. */ 166 for (i = 0; ; i++) 167 if (of_get_named_gpio(np, "gpios", i) < 0) 168 break; 169 config->nr_gpios = i; 170 171 config->gpios = devm_kzalloc(dev, 172 sizeof(struct gpio) * config->nr_gpios, 173 GFP_KERNEL); 174 if (!config->gpios) 175 return ERR_PTR(-ENOMEM); 176 177 for (i = 0; i < config->nr_gpios; i++) { 178 gpio = of_get_named_gpio(np, "gpios", i); 179 if (gpio < 0) 180 break; 181 config->gpios[i].gpio = gpio; 182 } 183 184 /* Fetch states. */ 185 prop = of_find_property(np, "states", NULL); 186 if (!prop) { 187 dev_err(dev, "No 'states' property found\n"); 188 return ERR_PTR(-EINVAL); 189 } 190 191 proplen = prop->length / sizeof(int); 192 193 config->states = devm_kzalloc(dev, 194 sizeof(struct gpio_regulator_state) 195 * (proplen / 2), 196 GFP_KERNEL); 197 if (!config->states) 198 return ERR_PTR(-ENOMEM); 199 200 for (i = 0; i < proplen / 2; i++) { 201 config->states[i].value = 202 be32_to_cpup((int *)prop->value + (i * 2)); 203 config->states[i].gpios = 204 be32_to_cpup((int *)prop->value + (i * 2 + 1)); 205 } 206 config->nr_states = i; 207 208 of_property_read_string(np, "regulator-type", ®type); 209 210 if (!strncmp("voltage", regtype, 7)) 211 config->type = REGULATOR_VOLTAGE; 212 else if (!strncmp("current", regtype, 7)) 213 config->type = REGULATOR_CURRENT; 214 215 return config; 216 } 217 218 static struct regulator_ops gpio_regulator_current_ops = { 219 .get_current_limit = gpio_regulator_get_value, 220 .set_current_limit = gpio_regulator_set_current_limit, 221 }; 222 223 static int gpio_regulator_probe(struct platform_device *pdev) 224 { 225 struct gpio_regulator_config *config = pdev->dev.platform_data; 226 struct device_node *np = pdev->dev.of_node; 227 struct gpio_regulator_data *drvdata; 228 struct regulator_config cfg = { }; 229 int ptr, ret, state; 230 231 if (np) { 232 config = of_get_gpio_regulator_config(&pdev->dev, np); 233 if (IS_ERR(config)) 234 return PTR_ERR(config); 235 } 236 237 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data), 238 GFP_KERNEL); 239 if (drvdata == NULL) { 240 dev_err(&pdev->dev, "Failed to allocate device data\n"); 241 return -ENOMEM; 242 } 243 244 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL); 245 if (drvdata->desc.name == NULL) { 246 dev_err(&pdev->dev, "Failed to allocate supply name\n"); 247 ret = -ENOMEM; 248 goto err; 249 } 250 251 drvdata->gpios = kmemdup(config->gpios, 252 config->nr_gpios * sizeof(struct gpio), 253 GFP_KERNEL); 254 if (drvdata->gpios == NULL) { 255 dev_err(&pdev->dev, "Failed to allocate gpio data\n"); 256 ret = -ENOMEM; 257 goto err_name; 258 } 259 260 drvdata->states = kmemdup(config->states, 261 config->nr_states * 262 sizeof(struct gpio_regulator_state), 263 GFP_KERNEL); 264 if (drvdata->states == NULL) { 265 dev_err(&pdev->dev, "Failed to allocate state data\n"); 266 ret = -ENOMEM; 267 goto err_memgpio; 268 } 269 drvdata->nr_states = config->nr_states; 270 271 drvdata->desc.owner = THIS_MODULE; 272 drvdata->desc.enable_time = config->startup_delay; 273 274 /* handle regulator type*/ 275 switch (config->type) { 276 case REGULATOR_VOLTAGE: 277 drvdata->desc.type = REGULATOR_VOLTAGE; 278 drvdata->desc.ops = &gpio_regulator_voltage_ops; 279 drvdata->desc.n_voltages = config->nr_states; 280 break; 281 case REGULATOR_CURRENT: 282 drvdata->desc.type = REGULATOR_CURRENT; 283 drvdata->desc.ops = &gpio_regulator_current_ops; 284 break; 285 default: 286 dev_err(&pdev->dev, "No regulator type set\n"); 287 ret = -EINVAL; 288 goto err_memgpio; 289 break; 290 } 291 292 drvdata->nr_gpios = config->nr_gpios; 293 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios); 294 if (ret) { 295 dev_err(&pdev->dev, 296 "Could not obtain regulator setting GPIOs: %d\n", ret); 297 goto err_memstate; 298 } 299 300 /* build initial state from gpio init data. */ 301 state = 0; 302 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) { 303 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH) 304 state |= (1 << ptr); 305 } 306 drvdata->state = state; 307 308 cfg.dev = &pdev->dev; 309 cfg.init_data = config->init_data; 310 cfg.driver_data = drvdata; 311 cfg.of_node = np; 312 313 if (config->enable_gpio >= 0) 314 cfg.ena_gpio = config->enable_gpio; 315 cfg.ena_gpio_invert = !config->enable_high; 316 if (config->enabled_at_boot) { 317 if (config->enable_high) 318 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH; 319 else 320 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW; 321 } else { 322 if (config->enable_high) 323 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW; 324 else 325 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH; 326 } 327 328 drvdata->dev = regulator_register(&drvdata->desc, &cfg); 329 if (IS_ERR(drvdata->dev)) { 330 ret = PTR_ERR(drvdata->dev); 331 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); 332 goto err_stategpio; 333 } 334 335 platform_set_drvdata(pdev, drvdata); 336 337 return 0; 338 339 err_stategpio: 340 gpio_free_array(drvdata->gpios, drvdata->nr_gpios); 341 err_memstate: 342 kfree(drvdata->states); 343 err_memgpio: 344 kfree(drvdata->gpios); 345 err_name: 346 kfree(drvdata->desc.name); 347 err: 348 return ret; 349 } 350 351 static int gpio_regulator_remove(struct platform_device *pdev) 352 { 353 struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev); 354 355 regulator_unregister(drvdata->dev); 356 357 gpio_free_array(drvdata->gpios, drvdata->nr_gpios); 358 359 kfree(drvdata->states); 360 kfree(drvdata->gpios); 361 362 kfree(drvdata->desc.name); 363 364 return 0; 365 } 366 367 #if defined(CONFIG_OF) 368 static const struct of_device_id regulator_gpio_of_match[] __devinitconst = { 369 { .compatible = "regulator-gpio", }, 370 {}, 371 }; 372 #endif 373 374 static struct platform_driver gpio_regulator_driver = { 375 .probe = gpio_regulator_probe, 376 .remove = gpio_regulator_remove, 377 .driver = { 378 .name = "gpio-regulator", 379 .owner = THIS_MODULE, 380 .of_match_table = of_match_ptr(regulator_gpio_of_match), 381 }, 382 }; 383 384 static int __init gpio_regulator_init(void) 385 { 386 return platform_driver_register(&gpio_regulator_driver); 387 } 388 subsys_initcall(gpio_regulator_init); 389 390 static void __exit gpio_regulator_exit(void) 391 { 392 platform_driver_unregister(&gpio_regulator_driver); 393 } 394 module_exit(gpio_regulator_exit); 395 396 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>"); 397 MODULE_DESCRIPTION("gpio voltage regulator"); 398 MODULE_LICENSE("GPL"); 399 MODULE_ALIAS("platform:gpio-regulator"); 400