1 // SPDX-License-Identifier: GPL-2.0-or-later
5 * Copyright 2008 Wolfson Microelectronics PLC.
7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
9 * Copyright (c) 2009 Nokia Corporation
10 * Roger Quadros <ext-roger.quadros@nokia.com>
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.
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>
28 #include <linux/of_device.h>
29 #include <linux/regulator/of_regulator.h>
30 #include <linux/regulator/machine.h>
31 #include <linux/clk.h>
34 struct fixed_voltage_data {
35 struct regulator_desc desc;
36 struct regulator_dev *dev;
38 struct clk *enable_clock;
39 unsigned int enable_counter;
40 int performance_state;
43 struct fixed_dev_type {
44 bool has_enable_clock;
45 bool has_performance_state;
48 static int reg_clock_enable(struct regulator_dev *rdev)
50 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
53 ret = clk_prepare_enable(priv->enable_clock);
57 priv->enable_counter++;
62 static int reg_clock_disable(struct regulator_dev *rdev)
64 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
66 clk_disable_unprepare(priv->enable_clock);
67 priv->enable_counter--;
72 static int reg_domain_enable(struct regulator_dev *rdev)
74 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
75 struct device *dev = rdev->dev.parent;
78 ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state);
82 priv->enable_counter++;
87 static int reg_domain_disable(struct regulator_dev *rdev)
89 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
90 struct device *dev = rdev->dev.parent;
93 ret = dev_pm_genpd_set_performance_state(dev, 0);
97 priv->enable_counter--;
102 static int reg_is_enabled(struct regulator_dev *rdev)
104 struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
106 return priv->enable_counter > 0;
111 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
112 * @dev: device requesting for fixed_voltage_config
113 * @desc: regulator description
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
119 static struct fixed_voltage_config *
120 of_get_fixed_voltage_config(struct device *dev,
121 const struct regulator_desc *desc)
123 struct fixed_voltage_config *config;
124 struct device_node *np = dev->of_node;
125 struct regulator_init_data *init_data;
127 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
130 return ERR_PTR(-ENOMEM);
132 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
133 if (!config->init_data)
134 return ERR_PTR(-EINVAL);
136 init_data = config->init_data;
137 init_data->constraints.apply_uV = 0;
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;
144 "Fixed regulator specified with variable voltages\n");
145 return ERR_PTR(-EINVAL);
148 if (init_data->constraints.boot_on)
149 config->enabled_at_boot = true;
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);
154 if (of_find_property(np, "vin-supply", NULL))
155 config->input_supply = "vin";
160 static const struct regulator_ops fixed_voltage_ops = {
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,
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,
175 static int reg_fixed_voltage_probe(struct platform_device *pdev)
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;
185 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
190 if (pdev->dev.of_node) {
191 config = of_get_fixed_voltage_config(&pdev->dev,
194 return PTR_ERR(config);
196 config = dev_get_platdata(&pdev->dev);
202 drvdata->desc.name = devm_kstrdup(&pdev->dev,
205 if (drvdata->desc.name == NULL) {
206 dev_err(&pdev->dev, "Failed to allocate supply name\n");
209 drvdata->desc.type = REGULATOR_VOLTAGE;
210 drvdata->desc.owner = THIS_MODULE;
212 if (drvtype && drvtype->has_enable_clock) {
213 drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
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");
220 } else if (drvtype && drvtype->has_performance_state) {
221 drvdata->desc.ops = &fixed_voltage_domain_ops;
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;
229 drvdata->desc.ops = &fixed_voltage_ops;
232 drvdata->desc.enable_time = config->startup_delay;
233 drvdata->desc.off_on_delay = config->off_on_delay;
235 if (config->input_supply) {
236 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
237 config->input_supply,
239 if (!drvdata->desc.supply_name)
243 if (config->microvolts)
244 drvdata->desc.n_voltages = 1;
246 drvdata->desc.fixed_uV = config->microvolts;
249 * The signal will be inverted by the GPIO core if flagged so in the
252 if (config->enabled_at_boot)
253 gflags = GPIOD_OUT_HIGH;
255 gflags = GPIOD_OUT_LOW;
258 * Some fixed regulators share the enable line between two
259 * regulators which makes it necessary to get a handle on the
260 * same descriptor for two different consumers. This will get
261 * the GPIO descriptor, but only the first call will initialize
262 * it so any flags such as inversion or open drain will only
263 * be set up by the first caller and assumed identical on the
266 * FIXME: find a better way to deal with this.
268 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
271 * Do not use devm* here: the regulator core takes over the
272 * lifecycle management of the GPIO descriptor.
274 cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
275 if (IS_ERR(cfg.ena_gpiod))
276 return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod),
279 cfg.dev = &pdev->dev;
280 cfg.init_data = config->init_data;
281 cfg.driver_data = drvdata;
282 cfg.of_node = pdev->dev.of_node;
284 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
286 if (IS_ERR(drvdata->dev)) {
287 ret = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev),
288 "Failed to register regulator: %ld\n",
289 PTR_ERR(drvdata->dev));
293 platform_set_drvdata(pdev, drvdata);
295 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
296 drvdata->desc.fixed_uV);
301 #if defined(CONFIG_OF)
302 static const struct fixed_dev_type fixed_voltage_data = {
303 .has_enable_clock = false,
306 static const struct fixed_dev_type fixed_clkenable_data = {
307 .has_enable_clock = true,
310 static const struct fixed_dev_type fixed_domain_data = {
311 .has_performance_state = true,
314 static const struct of_device_id fixed_of_match[] = {
316 .compatible = "regulator-fixed",
317 .data = &fixed_voltage_data,
320 .compatible = "regulator-fixed-clock",
321 .data = &fixed_clkenable_data,
324 .compatible = "regulator-fixed-domain",
325 .data = &fixed_domain_data,
330 MODULE_DEVICE_TABLE(of, fixed_of_match);
333 static struct platform_driver regulator_fixed_voltage_driver = {
334 .probe = reg_fixed_voltage_probe,
336 .name = "reg-fixed-voltage",
337 .of_match_table = of_match_ptr(fixed_of_match),
341 static int __init regulator_fixed_voltage_init(void)
343 return platform_driver_register(®ulator_fixed_voltage_driver);
345 subsys_initcall(regulator_fixed_voltage_init);
347 static void __exit regulator_fixed_voltage_exit(void)
349 platform_driver_unregister(®ulator_fixed_voltage_driver);
351 module_exit(regulator_fixed_voltage_exit);
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");