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/reboot.h> 24 #include <linux/regulator/driver.h> 25 #include <linux/regulator/fixed.h> 26 #include <linux/gpio/consumer.h> 27 #include <linux/slab.h> 28 #include <linux/of.h> 29 #include <linux/regulator/of_regulator.h> 30 #include <linux/regulator/machine.h> 31 #include <linux/clk.h> 32 33 /* Default time in millisecond to wait for emergency shutdown */ 34 #define FV_DEF_EMERG_SHUTDWN_TMO 10 35 36 struct fixed_voltage_data { 37 struct regulator_desc desc; 38 struct regulator_dev *dev; 39 40 struct clk *enable_clock; 41 unsigned int enable_counter; 42 int performance_state; 43 }; 44 45 struct fixed_dev_type { 46 bool has_enable_clock; 47 bool has_performance_state; 48 }; 49 50 static int reg_clock_enable(struct regulator_dev *rdev) 51 { 52 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 53 int ret = 0; 54 55 ret = clk_prepare_enable(priv->enable_clock); 56 if (ret) 57 return ret; 58 59 priv->enable_counter++; 60 61 return ret; 62 } 63 64 static int reg_clock_disable(struct regulator_dev *rdev) 65 { 66 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 67 68 clk_disable_unprepare(priv->enable_clock); 69 priv->enable_counter--; 70 71 return 0; 72 } 73 74 static int reg_domain_enable(struct regulator_dev *rdev) 75 { 76 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 77 struct device *dev = rdev->dev.parent; 78 int ret; 79 80 ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state); 81 if (ret) 82 return ret; 83 84 priv->enable_counter++; 85 86 return ret; 87 } 88 89 static int reg_domain_disable(struct regulator_dev *rdev) 90 { 91 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 92 struct device *dev = rdev->dev.parent; 93 int ret; 94 95 ret = dev_pm_genpd_set_performance_state(dev, 0); 96 if (ret) 97 return ret; 98 99 priv->enable_counter--; 100 101 return 0; 102 } 103 104 static int reg_is_enabled(struct regulator_dev *rdev) 105 { 106 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 107 108 return priv->enable_counter > 0; 109 } 110 111 static irqreturn_t reg_fixed_under_voltage_irq_handler(int irq, void *data) 112 { 113 struct fixed_voltage_data *priv = data; 114 struct regulator_dev *rdev = priv->dev; 115 116 regulator_notifier_call_chain(rdev, REGULATOR_EVENT_UNDER_VOLTAGE, 117 NULL); 118 119 return IRQ_HANDLED; 120 } 121 122 /** 123 * reg_fixed_get_irqs - Get and register the optional IRQ for fixed voltage 124 * regulator. 125 * @dev: Pointer to the device structure. 126 * @priv: Pointer to fixed_voltage_data structure containing private data. 127 * 128 * This function tries to get the IRQ from the device firmware node. 129 * If it's an optional IRQ and not found, it returns 0. 130 * Otherwise, it attempts to request the threaded IRQ. 131 * 132 * Return: 0 on success, or error code on failure. 133 */ 134 static int reg_fixed_get_irqs(struct device *dev, 135 struct fixed_voltage_data *priv) 136 { 137 int ret; 138 139 ret = fwnode_irq_get(dev_fwnode(dev), 0); 140 /* This is optional IRQ. If not found we will get -EINVAL */ 141 if (ret == -EINVAL) 142 return 0; 143 if (ret < 0) 144 return dev_err_probe(dev, ret, "Failed to get IRQ\n"); 145 146 ret = devm_request_threaded_irq(dev, ret, NULL, 147 reg_fixed_under_voltage_irq_handler, 148 IRQF_ONESHOT, "under-voltage", priv); 149 if (ret) 150 return dev_err_probe(dev, ret, "Failed to request IRQ\n"); 151 152 return 0; 153 } 154 155 /** 156 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info 157 * @dev: device requesting for fixed_voltage_config 158 * @desc: regulator description 159 * 160 * Populates fixed_voltage_config structure by extracting data from device 161 * tree node, returns a pointer to the populated structure of NULL if memory 162 * alloc fails. 163 */ 164 static struct fixed_voltage_config * 165 of_get_fixed_voltage_config(struct device *dev, 166 const struct regulator_desc *desc) 167 { 168 struct fixed_voltage_config *config; 169 struct device_node *np = dev->of_node; 170 struct regulator_init_data *init_data; 171 172 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), 173 GFP_KERNEL); 174 if (!config) 175 return ERR_PTR(-ENOMEM); 176 177 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc); 178 if (!config->init_data) 179 return ERR_PTR(-EINVAL); 180 181 init_data = config->init_data; 182 init_data->constraints.apply_uV = 0; 183 184 config->supply_name = init_data->constraints.name; 185 if (init_data->constraints.min_uV == init_data->constraints.max_uV) { 186 config->microvolts = init_data->constraints.min_uV; 187 } else { 188 dev_err(dev, 189 "Fixed regulator specified with variable voltages\n"); 190 return ERR_PTR(-EINVAL); 191 } 192 193 if (init_data->constraints.boot_on) 194 config->enabled_at_boot = true; 195 196 of_property_read_u32(np, "startup-delay-us", &config->startup_delay); 197 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay); 198 199 if (of_property_present(np, "vin-supply")) 200 config->input_supply = "vin"; 201 202 return config; 203 } 204 205 static const struct regulator_ops fixed_voltage_ops = { 206 }; 207 208 static const struct regulator_ops fixed_voltage_clkenabled_ops = { 209 .enable = reg_clock_enable, 210 .disable = reg_clock_disable, 211 .is_enabled = reg_is_enabled, 212 }; 213 214 static const struct regulator_ops fixed_voltage_domain_ops = { 215 .enable = reg_domain_enable, 216 .disable = reg_domain_disable, 217 .is_enabled = reg_is_enabled, 218 }; 219 220 static int reg_fixed_voltage_probe(struct platform_device *pdev) 221 { 222 struct device *dev = &pdev->dev; 223 struct fixed_voltage_config *config; 224 struct fixed_voltage_data *drvdata; 225 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev); 226 struct regulator_config cfg = { }; 227 enum gpiod_flags gflags; 228 int ret; 229 230 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data), 231 GFP_KERNEL); 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 ret = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev), 333 "Failed to register regulator: %ld\n", 334 PTR_ERR(drvdata->dev)); 335 return ret; 336 } 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