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