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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * fixed.c4 *5 * Copyright 2008 Wolfson Microelectronics PLC.6 *7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>8 *9 * Copyright (c) 2009 Nokia Corporation10 * Roger Quadros <ext-roger.quadros@nokia.com>11 *12 * This is useful for systems with mixed controllable and13 * non-controllable regulators, as well as for allowing testing on14 * 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 1035 36struct 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 45struct fixed_dev_type {46 bool has_enable_clock;47 bool has_performance_state;48};49 50static 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 64static 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 74static 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 89static 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 104static 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 111static 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 voltage124 * 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 */134static 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 info157 * @dev: device requesting for fixed_voltage_config158 * @desc: regulator description159 *160 * Populates fixed_voltage_config structure by extracting data from device161 * tree node.162 *163 * Return: Pointer to a populated &struct fixed_voltage_config or %NULL if164 * memory allocation fails.165 */166static struct fixed_voltage_config *167of_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 207static const struct regulator_ops fixed_voltage_ops = {208};209 210static 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 216static 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 222static 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 the297 * descriptor.298 */299 if (config->enabled_at_boot)300 gflags = GPIOD_OUT_HIGH;301 else302 gflags = GPIOD_OUT_LOW;303 304 /*305 * Some fixed regulators share the enable line between two306 * regulators which makes it necessary to get a handle on the307 * same descriptor for two different consumers. This will get308 * the GPIO descriptor, but only the first call will initialize309 * it so any flags such as inversion or open drain will only310 * be set up by the first caller and assumed identical on the311 * 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 the319 * 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)353static const struct fixed_dev_type fixed_voltage_data = {354 .has_enable_clock = false,355};356 357static const struct fixed_dev_type fixed_clkenable_data = {358 .has_enable_clock = true,359};360 361static const struct fixed_dev_type fixed_domain_data = {362 .has_performance_state = true,363};364 365static 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};381MODULE_DEVICE_TABLE(of, fixed_of_match);382#endif383 384static 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 393static int __init regulator_fixed_voltage_init(void)394{395 return platform_driver_register(®ulator_fixed_voltage_driver);396}397subsys_initcall(regulator_fixed_voltage_init);398 399static void __exit regulator_fixed_voltage_exit(void)400{401 platform_driver_unregister(®ulator_fixed_voltage_driver);402}403module_exit(regulator_fixed_voltage_exit);404 405MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");406MODULE_DESCRIPTION("Fixed voltage regulator");407MODULE_LICENSE("GPL");408MODULE_ALIAS("platform:reg-fixed-voltage");409