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