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 a negative error number 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. 162 * 163 * Return: Pointer to a populated &struct fixed_voltage_config or %NULL if 164 * memory allocation fails. 165 */ 166 static struct fixed_voltage_config * 167 of_get_fixed_voltage_config(struct device *dev, 168 const struct regulator_desc *desc) 169 { 170 struct fixed_voltage_config *config; 171 struct device_node *np = dev->of_node; 172 struct regulator_init_data *init_data; 173 174 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), 175 GFP_KERNEL); 176 if (!config) 177 return ERR_PTR(-ENOMEM); 178 179 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc); 180 if (!config->init_data) 181 return ERR_PTR(-EINVAL); 182 183 init_data = config->init_data; 184 init_data->constraints.apply_uV = 0; 185 186 config->supply_name = init_data->constraints.name; 187 if (init_data->constraints.min_uV == init_data->constraints.max_uV) { 188 config->microvolts = init_data->constraints.min_uV; 189 } else { 190 dev_err(dev, 191 "Fixed regulator specified with variable voltages\n"); 192 return ERR_PTR(-EINVAL); 193 } 194 195 if (init_data->constraints.boot_on) 196 config->enabled_at_boot = true; 197 198 of_property_read_u32(np, "startup-delay-us", &config->startup_delay); 199 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay); 200 201 if (of_property_present(np, "vin-supply")) 202 config->input_supply = "vin"; 203 204 return config; 205 } 206 207 static const struct regulator_ops fixed_voltage_ops = { 208 }; 209 210 static const struct regulator_ops fixed_voltage_clkenabled_ops = { 211 .enable = reg_clock_enable, 212 .disable = reg_clock_disable, 213 .is_enabled = reg_is_enabled, 214 }; 215 216 static const struct regulator_ops fixed_voltage_domain_ops = { 217 .enable = reg_domain_enable, 218 .disable = reg_domain_disable, 219 .is_enabled = reg_is_enabled, 220 }; 221 222 static int reg_fixed_voltage_probe(struct platform_device *pdev) 223 { 224 struct device *dev = &pdev->dev; 225 struct fixed_voltage_config *config; 226 struct fixed_voltage_data *drvdata; 227 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev); 228 struct regulator_config cfg = { }; 229 enum gpiod_flags gflags; 230 int ret; 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 ret = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev), 335 "Failed to register regulator: %ld\n", 336 PTR_ERR(drvdata->dev)); 337 return ret; 338 } 339 340 platform_set_drvdata(pdev, drvdata); 341 342 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, 343 drvdata->desc.fixed_uV); 344 345 ret = reg_fixed_get_irqs(dev, drvdata); 346 if (ret) 347 return ret; 348 349 return 0; 350 } 351 352 #if defined(CONFIG_OF) 353 static const struct fixed_dev_type fixed_voltage_data = { 354 .has_enable_clock = false, 355 }; 356 357 static const struct fixed_dev_type fixed_clkenable_data = { 358 .has_enable_clock = true, 359 }; 360 361 static const struct fixed_dev_type fixed_domain_data = { 362 .has_performance_state = true, 363 }; 364 365 static const struct of_device_id fixed_of_match[] = { 366 { 367 .compatible = "regulator-fixed", 368 .data = &fixed_voltage_data, 369 }, 370 { 371 .compatible = "regulator-fixed-clock", 372 .data = &fixed_clkenable_data, 373 }, 374 { 375 .compatible = "regulator-fixed-domain", 376 .data = &fixed_domain_data, 377 }, 378 { 379 }, 380 }; 381 MODULE_DEVICE_TABLE(of, fixed_of_match); 382 #endif 383 384 static struct platform_driver regulator_fixed_voltage_driver = { 385 .probe = reg_fixed_voltage_probe, 386 .driver = { 387 .name = "reg-fixed-voltage", 388 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 389 .of_match_table = of_match_ptr(fixed_of_match), 390 }, 391 }; 392 393 static int __init regulator_fixed_voltage_init(void) 394 { 395 return platform_driver_register(®ulator_fixed_voltage_driver); 396 } 397 subsys_initcall(regulator_fixed_voltage_init); 398 399 static void __exit regulator_fixed_voltage_exit(void) 400 { 401 platform_driver_unregister(®ulator_fixed_voltage_driver); 402 } 403 module_exit(regulator_fixed_voltage_exit); 404 405 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 406 MODULE_DESCRIPTION("Fixed voltage regulator"); 407 MODULE_LICENSE("GPL"); 408 MODULE_ALIAS("platform:reg-fixed-voltage"); 409