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_obj(dev, struct fixed_voltage_config); 172 if (!config) 173 return ERR_PTR(-ENOMEM); 174 175 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc); 176 if (!config->init_data) 177 return ERR_PTR(-EINVAL); 178 179 init_data = config->init_data; 180 init_data->constraints.apply_uV = 0; 181 182 config->supply_name = init_data->constraints.name; 183 if (init_data->constraints.min_uV == init_data->constraints.max_uV) { 184 config->microvolts = init_data->constraints.min_uV; 185 } else { 186 dev_err(dev, 187 "Fixed regulator specified with variable voltages\n"); 188 return ERR_PTR(-EINVAL); 189 } 190 191 if (init_data->constraints.boot_on) 192 config->enabled_at_boot = true; 193 194 of_property_read_u32(np, "startup-delay-us", &config->startup_delay); 195 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay); 196 197 if (of_property_present(np, "vin-supply")) 198 config->input_supply = "vin"; 199 200 return config; 201 } 202 203 static const struct regulator_ops fixed_voltage_ops = { 204 }; 205 206 static const struct regulator_ops fixed_voltage_clkenabled_ops = { 207 .enable = reg_clock_enable, 208 .disable = reg_clock_disable, 209 .is_enabled = reg_is_enabled, 210 }; 211 212 static const struct regulator_ops fixed_voltage_domain_ops = { 213 .enable = reg_domain_enable, 214 .disable = reg_domain_disable, 215 .is_enabled = reg_is_enabled, 216 }; 217 218 static int reg_fixed_voltage_probe(struct platform_device *pdev) 219 { 220 struct device *dev = &pdev->dev; 221 struct fixed_voltage_config *config; 222 struct fixed_voltage_data *drvdata; 223 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev); 224 struct regulator_config cfg = { }; 225 enum gpiod_flags gflags; 226 int ret; 227 228 if (!pdev->dev.of_node && strcmp(pdev->name, "reg-fixed-voltage")) 229 return -ENODEV; 230 231 drvdata = devm_kzalloc_obj(&pdev->dev, struct fixed_voltage_data); 232 if (!drvdata) 233 return -ENOMEM; 234 235 if (pdev->dev.of_node) { 236 config = of_get_fixed_voltage_config(&pdev->dev, 237 &drvdata->desc); 238 if (IS_ERR(config)) 239 return PTR_ERR(config); 240 } else { 241 config = dev_get_platdata(&pdev->dev); 242 } 243 244 if (!config) 245 return -ENOMEM; 246 247 drvdata->desc.name = devm_kstrdup(&pdev->dev, 248 config->supply_name, 249 GFP_KERNEL); 250 if (drvdata->desc.name == NULL) { 251 dev_err(&pdev->dev, "Failed to allocate supply name\n"); 252 return -ENOMEM; 253 } 254 drvdata->desc.type = REGULATOR_VOLTAGE; 255 drvdata->desc.owner = THIS_MODULE; 256 257 if (drvtype && drvtype->has_enable_clock) { 258 drvdata->desc.ops = &fixed_voltage_clkenabled_ops; 259 260 drvdata->enable_clock = devm_clk_get(dev, NULL); 261 if (IS_ERR(drvdata->enable_clock)) { 262 dev_err(dev, "Can't get enable-clock from devicetree\n"); 263 return PTR_ERR(drvdata->enable_clock); 264 } 265 } else if (drvtype && drvtype->has_performance_state) { 266 drvdata->desc.ops = &fixed_voltage_domain_ops; 267 268 drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0); 269 if (drvdata->performance_state < 0) { 270 dev_err(dev, "Can't get performance state from devicetree\n"); 271 return drvdata->performance_state; 272 } 273 } else { 274 drvdata->desc.ops = &fixed_voltage_ops; 275 } 276 277 drvdata->desc.enable_time = config->startup_delay; 278 drvdata->desc.off_on_delay = config->off_on_delay; 279 280 if (config->input_supply) { 281 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev, 282 config->input_supply, 283 GFP_KERNEL); 284 if (!drvdata->desc.supply_name) 285 return -ENOMEM; 286 } 287 288 if (config->microvolts) 289 drvdata->desc.n_voltages = 1; 290 291 drvdata->desc.fixed_uV = config->microvolts; 292 293 /* 294 * The signal will be inverted by the GPIO core if flagged so in the 295 * descriptor. 296 */ 297 if (config->enabled_at_boot) 298 gflags = GPIOD_OUT_HIGH; 299 else 300 gflags = GPIOD_OUT_LOW; 301 302 /* 303 * Some fixed regulators share the enable line between two 304 * regulators which makes it necessary to get a handle on the 305 * same descriptor for two different consumers. This will get 306 * the GPIO descriptor, but only the first call will initialize 307 * it so any flags such as inversion or open drain will only 308 * be set up by the first caller and assumed identical on the 309 * next caller. 310 * 311 * FIXME: find a better way to deal with this. 312 */ 313 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE; 314 315 /* 316 * Do not use devm* here: the regulator core takes over the 317 * lifecycle management of the GPIO descriptor. 318 */ 319 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags); 320 if (IS_ERR(cfg.ena_gpiod)) 321 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod), 322 "can't get GPIO\n"); 323 324 cfg.dev = &pdev->dev; 325 cfg.init_data = config->init_data; 326 cfg.driver_data = drvdata; 327 cfg.of_node = pdev->dev.of_node; 328 329 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc, 330 &cfg); 331 if (IS_ERR(drvdata->dev)) 332 return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev), 333 "Failed to register regulator: %ld\n", 334 PTR_ERR(drvdata->dev)); 335 336 platform_set_drvdata(pdev, drvdata); 337 338 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, 339 drvdata->desc.fixed_uV); 340 341 ret = reg_fixed_get_irqs(dev, drvdata); 342 if (ret) 343 return ret; 344 345 return 0; 346 } 347 348 #if defined(CONFIG_OF) 349 static const struct fixed_dev_type fixed_voltage_data = { 350 .has_enable_clock = false, 351 }; 352 353 static const struct fixed_dev_type fixed_clkenable_data = { 354 .has_enable_clock = true, 355 }; 356 357 static const struct fixed_dev_type fixed_domain_data = { 358 .has_performance_state = true, 359 }; 360 361 static const struct of_device_id fixed_of_match[] = { 362 { 363 .compatible = "regulator-fixed", 364 .data = &fixed_voltage_data, 365 }, 366 { 367 .compatible = "regulator-fixed-clock", 368 .data = &fixed_clkenable_data, 369 }, 370 { 371 .compatible = "regulator-fixed-domain", 372 .data = &fixed_domain_data, 373 }, 374 { 375 }, 376 }; 377 MODULE_DEVICE_TABLE(of, fixed_of_match); 378 #endif 379 380 static struct platform_driver regulator_fixed_voltage_driver = { 381 .probe = reg_fixed_voltage_probe, 382 .driver = { 383 .name = "reg-fixed-voltage", 384 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 385 .of_match_table = of_match_ptr(fixed_of_match), 386 }, 387 }; 388 389 static int __init regulator_fixed_voltage_init(void) 390 { 391 return platform_driver_register(®ulator_fixed_voltage_driver); 392 } 393 subsys_initcall(regulator_fixed_voltage_init); 394 395 static void __exit regulator_fixed_voltage_exit(void) 396 { 397 platform_driver_unregister(®ulator_fixed_voltage_driver); 398 } 399 module_exit(regulator_fixed_voltage_exit); 400 401 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 402 MODULE_DESCRIPTION("Fixed voltage regulator"); 403 MODULE_LICENSE("GPL"); 404 MODULE_ALIAS("platform:reg-fixed-voltage"); 405