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/of_device.h> 29 #include <linux/regulator/of_regulator.h> 30 #include <linux/regulator/machine.h> 31 #include <linux/clk.h> 32 33 34 struct fixed_voltage_data { 35 struct regulator_desc desc; 36 struct regulator_dev *dev; 37 38 struct clk *enable_clock; 39 unsigned int enable_counter; 40 int performance_state; 41 }; 42 43 struct fixed_dev_type { 44 bool has_enable_clock; 45 bool has_performance_state; 46 }; 47 48 static int reg_clock_enable(struct regulator_dev *rdev) 49 { 50 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 51 int ret = 0; 52 53 ret = clk_prepare_enable(priv->enable_clock); 54 if (ret) 55 return ret; 56 57 priv->enable_counter++; 58 59 return ret; 60 } 61 62 static int reg_clock_disable(struct regulator_dev *rdev) 63 { 64 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 65 66 clk_disable_unprepare(priv->enable_clock); 67 priv->enable_counter--; 68 69 return 0; 70 } 71 72 static int reg_domain_enable(struct regulator_dev *rdev) 73 { 74 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 75 struct device *dev = rdev->dev.parent; 76 int ret; 77 78 ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state); 79 if (ret) 80 return ret; 81 82 priv->enable_counter++; 83 84 return ret; 85 } 86 87 static int reg_domain_disable(struct regulator_dev *rdev) 88 { 89 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 90 struct device *dev = rdev->dev.parent; 91 int ret; 92 93 ret = dev_pm_genpd_set_performance_state(dev, 0); 94 if (ret) 95 return ret; 96 97 priv->enable_counter--; 98 99 return 0; 100 } 101 102 static int reg_is_enabled(struct regulator_dev *rdev) 103 { 104 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); 105 106 return priv->enable_counter > 0; 107 } 108 109 110 /** 111 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info 112 * @dev: device requesting for fixed_voltage_config 113 * @desc: regulator description 114 * 115 * Populates fixed_voltage_config structure by extracting data from device 116 * tree node, returns a pointer to the populated structure of NULL if memory 117 * alloc fails. 118 */ 119 static struct fixed_voltage_config * 120 of_get_fixed_voltage_config(struct device *dev, 121 const struct regulator_desc *desc) 122 { 123 struct fixed_voltage_config *config; 124 struct device_node *np = dev->of_node; 125 struct regulator_init_data *init_data; 126 127 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), 128 GFP_KERNEL); 129 if (!config) 130 return ERR_PTR(-ENOMEM); 131 132 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc); 133 if (!config->init_data) 134 return ERR_PTR(-EINVAL); 135 136 init_data = config->init_data; 137 init_data->constraints.apply_uV = 0; 138 139 config->supply_name = init_data->constraints.name; 140 if (init_data->constraints.min_uV == init_data->constraints.max_uV) { 141 config->microvolts = init_data->constraints.min_uV; 142 } else { 143 dev_err(dev, 144 "Fixed regulator specified with variable voltages\n"); 145 return ERR_PTR(-EINVAL); 146 } 147 148 if (init_data->constraints.boot_on) 149 config->enabled_at_boot = true; 150 151 of_property_read_u32(np, "startup-delay-us", &config->startup_delay); 152 of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay); 153 154 if (of_find_property(np, "vin-supply", NULL)) 155 config->input_supply = "vin"; 156 157 return config; 158 } 159 160 static const struct regulator_ops fixed_voltage_ops = { 161 }; 162 163 static const struct regulator_ops fixed_voltage_clkenabled_ops = { 164 .enable = reg_clock_enable, 165 .disable = reg_clock_disable, 166 .is_enabled = reg_is_enabled, 167 }; 168 169 static const struct regulator_ops fixed_voltage_domain_ops = { 170 .enable = reg_domain_enable, 171 .disable = reg_domain_disable, 172 .is_enabled = reg_is_enabled, 173 }; 174 175 static int reg_fixed_voltage_probe(struct platform_device *pdev) 176 { 177 struct device *dev = &pdev->dev; 178 struct fixed_voltage_config *config; 179 struct fixed_voltage_data *drvdata; 180 const struct fixed_dev_type *drvtype = of_device_get_match_data(dev); 181 struct regulator_config cfg = { }; 182 enum gpiod_flags gflags; 183 int ret; 184 185 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data), 186 GFP_KERNEL); 187 if (!drvdata) 188 return -ENOMEM; 189 190 if (pdev->dev.of_node) { 191 config = of_get_fixed_voltage_config(&pdev->dev, 192 &drvdata->desc); 193 if (IS_ERR(config)) 194 return PTR_ERR(config); 195 } else { 196 config = dev_get_platdata(&pdev->dev); 197 } 198 199 if (!config) 200 return -ENOMEM; 201 202 drvdata->desc.name = devm_kstrdup(&pdev->dev, 203 config->supply_name, 204 GFP_KERNEL); 205 if (drvdata->desc.name == NULL) { 206 dev_err(&pdev->dev, "Failed to allocate supply name\n"); 207 return -ENOMEM; 208 } 209 drvdata->desc.type = REGULATOR_VOLTAGE; 210 drvdata->desc.owner = THIS_MODULE; 211 212 if (drvtype && drvtype->has_enable_clock) { 213 drvdata->desc.ops = &fixed_voltage_clkenabled_ops; 214 215 drvdata->enable_clock = devm_clk_get(dev, NULL); 216 if (IS_ERR(drvdata->enable_clock)) { 217 dev_err(dev, "Can't get enable-clock from devicetree\n"); 218 return -ENOENT; 219 } 220 } else if (drvtype && drvtype->has_performance_state) { 221 drvdata->desc.ops = &fixed_voltage_domain_ops; 222 223 drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0); 224 if (drvdata->performance_state < 0) { 225 dev_err(dev, "Can't get performance state from devicetree\n"); 226 return drvdata->performance_state; 227 } 228 } else { 229 drvdata->desc.ops = &fixed_voltage_ops; 230 } 231 232 drvdata->desc.enable_time = config->startup_delay; 233 drvdata->desc.off_on_delay = config->off_on_delay; 234 235 if (config->input_supply) { 236 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev, 237 config->input_supply, 238 GFP_KERNEL); 239 if (!drvdata->desc.supply_name) { 240 dev_err(&pdev->dev, 241 "Failed to allocate input supply\n"); 242 return -ENOMEM; 243 } 244 } 245 246 if (config->microvolts) 247 drvdata->desc.n_voltages = 1; 248 249 drvdata->desc.fixed_uV = config->microvolts; 250 251 /* 252 * The signal will be inverted by the GPIO core if flagged so in the 253 * descriptor. 254 */ 255 if (config->enabled_at_boot) 256 gflags = GPIOD_OUT_HIGH; 257 else 258 gflags = GPIOD_OUT_LOW; 259 260 /* 261 * Some fixed regulators share the enable line between two 262 * regulators which makes it necessary to get a handle on the 263 * same descriptor for two different consumers. This will get 264 * the GPIO descriptor, but only the first call will initialize 265 * it so any flags such as inversion or open drain will only 266 * be set up by the first caller and assumed identical on the 267 * next caller. 268 * 269 * FIXME: find a better way to deal with this. 270 */ 271 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE; 272 273 /* 274 * Do not use devm* here: the regulator core takes over the 275 * lifecycle management of the GPIO descriptor. 276 */ 277 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags); 278 if (IS_ERR(cfg.ena_gpiod)) 279 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod), 280 "can't get GPIO\n"); 281 282 cfg.dev = &pdev->dev; 283 cfg.init_data = config->init_data; 284 cfg.driver_data = drvdata; 285 cfg.of_node = pdev->dev.of_node; 286 287 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc, 288 &cfg); 289 if (IS_ERR(drvdata->dev)) { 290 ret = PTR_ERR(drvdata->dev); 291 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); 292 return ret; 293 } 294 295 platform_set_drvdata(pdev, drvdata); 296 297 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, 298 drvdata->desc.fixed_uV); 299 300 return 0; 301 } 302 303 #if defined(CONFIG_OF) 304 static const struct fixed_dev_type fixed_voltage_data = { 305 .has_enable_clock = false, 306 }; 307 308 static const struct fixed_dev_type fixed_clkenable_data = { 309 .has_enable_clock = true, 310 }; 311 312 static const struct fixed_dev_type fixed_domain_data = { 313 .has_performance_state = true, 314 }; 315 316 static const struct of_device_id fixed_of_match[] = { 317 { 318 .compatible = "regulator-fixed", 319 .data = &fixed_voltage_data, 320 }, 321 { 322 .compatible = "regulator-fixed-clock", 323 .data = &fixed_clkenable_data, 324 }, 325 { 326 .compatible = "regulator-fixed-domain", 327 .data = &fixed_domain_data, 328 }, 329 { 330 }, 331 }; 332 MODULE_DEVICE_TABLE(of, fixed_of_match); 333 #endif 334 335 static struct platform_driver regulator_fixed_voltage_driver = { 336 .probe = reg_fixed_voltage_probe, 337 .driver = { 338 .name = "reg-fixed-voltage", 339 .of_match_table = of_match_ptr(fixed_of_match), 340 }, 341 }; 342 343 static int __init regulator_fixed_voltage_init(void) 344 { 345 return platform_driver_register(®ulator_fixed_voltage_driver); 346 } 347 subsys_initcall(regulator_fixed_voltage_init); 348 349 static void __exit regulator_fixed_voltage_exit(void) 350 { 351 platform_driver_unregister(®ulator_fixed_voltage_driver); 352 } 353 module_exit(regulator_fixed_voltage_exit); 354 355 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 356 MODULE_DESCRIPTION("Fixed voltage regulator"); 357 MODULE_LICENSE("GPL"); 358 MODULE_ALIAS("platform:reg-fixed-voltage"); 359