1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * fixed.c 4 * 5 * Copyright 2008 Wolfson Microelectronics PLC. 6 * 7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 8 * 9 * Copyright (c) 2009 Nokia Corporation 10 * Roger Quadros <ext-roger.quadros@nokia.com> 11 * 12 * This is useful for systems with mixed controllable and 13 * non-controllable regulators, as well as for allowing testing on 14 * systems with no controllable regulators. 15 */ 16 17 #include <linux/err.h> 18 #include <linux/mutex.h> 19 #include <linux/module.h> 20 #include <linux/platform_device.h> 21 #include <linux/pm_domain.h> 22 #include <linux/pm_opp.h> 23 #include <linux/regulator/driver.h> 24 #include <linux/regulator/fixed.h> 25 #include <linux/gpio/consumer.h> 26 #include <linux/slab.h> 27 #include <linux/of.h> 28 #include <linux/regulator/of_regulator.h> 29 #include <linux/regulator/machine.h> 30 #include <linux/clk.h> 31 #include <linux/string.h> 32 33 struct fixed_voltage_data { 34 struct regulator_desc desc; 35 struct regulator_dev *dev; 36 37 struct clk *enable_clock; 38 unsigned int enable_counter; 39 int performance_state; 40 }; 41 42 struct fixed_dev_type { 43 bool has_enable_clock; 44 bool has_performance_state; 45 }; 46 47 static int reg_clock_enable(struct regulator_dev *rdev) 48 { 49 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 50 int ret = 0; 51 52 ret = clk_prepare_enable(priv->enable_clock); 53 if (ret) 54 return ret; 55 56 priv->enable_counter++; 57 58 return ret; 59 } 60 61 static int reg_clock_disable(struct regulator_dev *rdev) 62 { 63 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 64 65 clk_disable_unprepare(priv->enable_clock); 66 priv->enable_counter--; 67 68 return 0; 69 } 70 71 static int reg_domain_enable(struct regulator_dev *rdev) 72 { 73 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 74 struct device *dev = rdev->dev.parent; 75 int ret; 76 77 ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state); 78 if (ret) 79 return ret; 80 81 priv->enable_counter++; 82 83 return ret; 84 } 85 86 static int reg_domain_disable(struct regulator_dev *rdev) 87 { 88 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 89 struct device *dev = rdev->dev.parent; 90 int ret; 91 92 ret = dev_pm_genpd_set_performance_state(dev, 0); 93 if (ret) 94 return ret; 95 96 priv->enable_counter--; 97 98 return 0; 99 } 100 101 static int reg_is_enabled(struct regulator_dev *rdev) 102 { 103 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 104 105 return priv->enable_counter > 0; 106 } 107 108 static irqreturn_t reg_fixed_under_voltage_irq_handler(int irq, void *data) 109 { 110 struct fixed_voltage_data *priv = data; 111 struct regulator_dev *rdev = priv->dev; 112 113 regulator_notifier_call_chain(rdev, REGULATOR_EVENT_UNDER_VOLTAGE, 114 NULL); 115 116 return IRQ_HANDLED; 117 } 118 119 /** 120 * reg_fixed_get_irqs - Get and register the optional IRQ for fixed voltage 121 * regulator. 122 * @dev: Pointer to the device structure. 123 * @priv: Pointer to fixed_voltage_data structure containing private data. 124 * 125 * This function tries to get the IRQ from the device firmware node. 126 * If it's an optional IRQ and not found, it returns 0. 127 * Otherwise, it attempts to request the threaded IRQ. 128 * 129 * Return: 0 on success, or a negative error number on failure. 130 */ 131 static int reg_fixed_get_irqs(struct device *dev, 132 struct fixed_voltage_data *priv) 133 { 134 int ret; 135 136 ret = fwnode_irq_get(dev_fwnode(dev), 0); 137 /* This is optional IRQ. If not found we will get -EINVAL */ 138 if (ret == -EINVAL) 139 return 0; 140 if (ret < 0) 141 return dev_err_probe(dev, ret, "Failed to get IRQ\n"); 142 143 ret = devm_request_threaded_irq(dev, ret, NULL, 144 reg_fixed_under_voltage_irq_handler, 145 IRQF_ONESHOT, "under-voltage", priv); 146 if (ret) 147 return dev_err_probe(dev, ret, "Failed to request IRQ\n"); 148 149 return 0; 150 } 151 152 /** 153 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info 154 * @dev: device requesting for fixed_voltage_config 155 * @desc: regulator description 156 * 157 * Populates fixed_voltage_config structure by extracting data from device 158 * tree node. 159 * 160 * Return: Pointer to a populated &struct fixed_voltage_config or %NULL if 161 * memory allocation fails. 162 */ 163 static struct fixed_voltage_config * 164 of_get_fixed_voltage_config(struct device *dev, 165 const struct regulator_desc *desc) 166 { 167 struct fixed_voltage_config *config; 168 struct device_node *np = dev->of_node; 169 struct regulator_init_data *init_data; 170 171 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), 172 GFP_KERNEL); 173 if (!config) 174 return ERR_PTR(-ENOMEM); 175 176 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc); 177 if (!config->init_data) 178 return ERR_PTR(-EINVAL); 179 180 init_data = config->init_data; 181 init_data->constraints.apply_uV = 0; 182 183 config->supply_name = init_data->constraints.name; 184 if (init_data->constraints.min_uV == init_data->constraints.max_uV) { 185 config->microvolts = init_data->constraints.min_uV; 186 } else { 187 dev_err(dev, 188 "Fixed regulator specified with variable voltages\n"); 189 return ERR_PTR(-EINVAL); 190 } 191 192 if (init_data->constraints.boot_on) 193 config->enabled_at_boot = true; 194 195 of_property_read_u32(np, "startup-delay-us", &config->startup_delay); 196 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay); 197 198 if (of_property_present(np, "vin-supply")) 199 config->input_supply = "vin"; 200 201 return config; 202 } 203 204 static const struct regulator_ops fixed_voltage_ops = { 205 }; 206 207 static const struct regulator_ops fixed_voltage_clkenabled_ops = { 208 .enable = reg_clock_enable, 209 .disable = reg_clock_disable, 210 .is_enabled = reg_is_enabled, 211 }; 212 213 static const struct regulator_ops fixed_voltage_domain_ops = { 214 .enable = reg_domain_enable, 215 .disable = reg_domain_disable, 216 .is_enabled = reg_is_enabled, 217 }; 218 219 static int reg_fixed_voltage_probe(struct platform_device *pdev) 220 { 221 struct device *dev = &pdev->dev; 222 struct fixed_voltage_config *config; 223 struct fixed_voltage_data *drvdata; 224 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev); 225 struct regulator_config cfg = { }; 226 enum gpiod_flags gflags; 227 int ret; 228 229 if (!pdev->dev.of_node && strcmp(pdev->name, "reg-fixed-voltage")) 230 return -ENODEV; 231 232 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data), 233 GFP_KERNEL); 234 if (!drvdata) 235 return -ENOMEM; 236 237 if (pdev->dev.of_node) { 238 config = of_get_fixed_voltage_config(&pdev->dev, 239 &drvdata->desc); 240 if (IS_ERR(config)) 241 return PTR_ERR(config); 242 } else { 243 config = dev_get_platdata(&pdev->dev); 244 } 245 246 if (!config) 247 return -ENOMEM; 248 249 drvdata->desc.name = devm_kstrdup(&pdev->dev, 250 config->supply_name, 251 GFP_KERNEL); 252 if (drvdata->desc.name == NULL) { 253 dev_err(&pdev->dev, "Failed to allocate supply name\n"); 254 return -ENOMEM; 255 } 256 drvdata->desc.type = REGULATOR_VOLTAGE; 257 drvdata->desc.owner = THIS_MODULE; 258 259 if (drvtype && drvtype->has_enable_clock) { 260 drvdata->desc.ops = &fixed_voltage_clkenabled_ops; 261 262 drvdata->enable_clock = devm_clk_get(dev, NULL); 263 if (IS_ERR(drvdata->enable_clock)) { 264 dev_err(dev, "Can't get enable-clock from devicetree\n"); 265 return PTR_ERR(drvdata->enable_clock); 266 } 267 } else if (drvtype && drvtype->has_performance_state) { 268 drvdata->desc.ops = &fixed_voltage_domain_ops; 269 270 drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0); 271 if (drvdata->performance_state < 0) { 272 dev_err(dev, "Can't get performance state from devicetree\n"); 273 return drvdata->performance_state; 274 } 275 } else { 276 drvdata->desc.ops = &fixed_voltage_ops; 277 } 278 279 drvdata->desc.enable_time = config->startup_delay; 280 drvdata->desc.off_on_delay = config->off_on_delay; 281 282 if (config->input_supply) { 283 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev, 284 config->input_supply, 285 GFP_KERNEL); 286 if (!drvdata->desc.supply_name) 287 return -ENOMEM; 288 } 289 290 if (config->microvolts) 291 drvdata->desc.n_voltages = 1; 292 293 drvdata->desc.fixed_uV = config->microvolts; 294 295 /* 296 * The signal will be inverted by the GPIO core if flagged so in the 297 * descriptor. 298 */ 299 if (config->enabled_at_boot) 300 gflags = GPIOD_OUT_HIGH; 301 else 302 gflags = GPIOD_OUT_LOW; 303 304 /* 305 * Some fixed regulators share the enable line between two 306 * regulators which makes it necessary to get a handle on the 307 * same descriptor for two different consumers. This will get 308 * the GPIO descriptor, but only the first call will initialize 309 * it so any flags such as inversion or open drain will only 310 * be set up by the first caller and assumed identical on the 311 * next caller. 312 * 313 * FIXME: find a better way to deal with this. 314 */ 315 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE; 316 317 /* 318 * Do not use devm* here: the regulator core takes over the 319 * lifecycle management of the GPIO descriptor. 320 */ 321 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags); 322 if (IS_ERR(cfg.ena_gpiod)) 323 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod), 324 "can't get GPIO\n"); 325 326 cfg.dev = &pdev->dev; 327 cfg.init_data = config->init_data; 328 cfg.driver_data = drvdata; 329 cfg.of_node = pdev->dev.of_node; 330 331 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc, 332 &cfg); 333 if (IS_ERR(drvdata->dev)) 334 return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev), 335 "Failed to register regulator: %ld\n", 336 PTR_ERR(drvdata->dev)); 337 338 platform_set_drvdata(pdev, drvdata); 339 340 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, 341 drvdata->desc.fixed_uV); 342 343 ret = reg_fixed_get_irqs(dev, drvdata); 344 if (ret) 345 return ret; 346 347 return 0; 348 } 349 350 #if defined(CONFIG_OF) 351 static const struct fixed_dev_type fixed_voltage_data = { 352 .has_enable_clock = false, 353 }; 354 355 static const struct fixed_dev_type fixed_clkenable_data = { 356 .has_enable_clock = true, 357 }; 358 359 static const struct fixed_dev_type fixed_domain_data = { 360 .has_performance_state = true, 361 }; 362 363 static const struct of_device_id fixed_of_match[] = { 364 { 365 .compatible = "regulator-fixed", 366 .data = &fixed_voltage_data, 367 }, 368 { 369 .compatible = "regulator-fixed-clock", 370 .data = &fixed_clkenable_data, 371 }, 372 { 373 .compatible = "regulator-fixed-domain", 374 .data = &fixed_domain_data, 375 }, 376 { 377 }, 378 }; 379 MODULE_DEVICE_TABLE(of, fixed_of_match); 380 #endif 381 382 static struct platform_driver regulator_fixed_voltage_driver = { 383 .probe = reg_fixed_voltage_probe, 384 .driver = { 385 .name = "reg-fixed-voltage", 386 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 387 .of_match_table = of_match_ptr(fixed_of_match), 388 }, 389 }; 390 391 static int __init regulator_fixed_voltage_init(void) 392 { 393 return platform_driver_register(®ulator_fixed_voltage_driver); 394 } 395 subsys_initcall(regulator_fixed_voltage_init); 396 397 static void __exit regulator_fixed_voltage_exit(void) 398 { 399 platform_driver_unregister(®ulator_fixed_voltage_driver); 400 } 401 module_exit(regulator_fixed_voltage_exit); 402 403 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 404 MODULE_DESCRIPTION("Fixed voltage regulator"); 405 MODULE_LICENSE("GPL"); 406 MODULE_ALIAS("platform:reg-fixed-voltage"); 407