GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / regulator / fixed.c
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/regulator/driver.h>
22 #include <linux/regulator/fixed.h>
23 #include <linux/gpio/consumer.h>
24 #include <linux/slab.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27 #include <linux/regulator/of_regulator.h>
28 #include <linux/regulator/machine.h>
29 #include <linux/clk.h>
30
31
32 struct fixed_voltage_data {
33         struct regulator_desc desc;
34         struct regulator_dev *dev;
35
36         struct clk *enable_clock;
37         unsigned int clk_enable_counter;
38 };
39
40 struct fixed_dev_type {
41         bool has_enable_clock;
42 };
43
44 static int reg_clock_enable(struct regulator_dev *rdev)
45 {
46         struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
47         int ret = 0;
48
49         ret = clk_prepare_enable(priv->enable_clock);
50         if (ret)
51                 return ret;
52
53         priv->clk_enable_counter++;
54
55         return ret;
56 }
57
58 static int reg_clock_disable(struct regulator_dev *rdev)
59 {
60         struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
61
62         clk_disable_unprepare(priv->enable_clock);
63         priv->clk_enable_counter--;
64
65         return 0;
66 }
67
68 static int reg_clock_is_enabled(struct regulator_dev *rdev)
69 {
70         struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
71
72         return priv->clk_enable_counter > 0;
73 }
74
75
76 /**
77  * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
78  * @dev: device requesting for fixed_voltage_config
79  * @desc: regulator description
80  *
81  * Populates fixed_voltage_config structure by extracting data from device
82  * tree node, returns a pointer to the populated structure of NULL if memory
83  * alloc fails.
84  */
85 static struct fixed_voltage_config *
86 of_get_fixed_voltage_config(struct device *dev,
87                             const struct regulator_desc *desc)
88 {
89         struct fixed_voltage_config *config;
90         struct device_node *np = dev->of_node;
91         struct regulator_init_data *init_data;
92
93         config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
94                                                                  GFP_KERNEL);
95         if (!config)
96                 return ERR_PTR(-ENOMEM);
97
98         config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
99         if (!config->init_data)
100                 return ERR_PTR(-EINVAL);
101
102         init_data = config->init_data;
103         init_data->constraints.apply_uV = 0;
104
105         config->supply_name = init_data->constraints.name;
106         if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
107                 config->microvolts = init_data->constraints.min_uV;
108         } else {
109                 dev_err(dev,
110                          "Fixed regulator specified with variable voltages\n");
111                 return ERR_PTR(-EINVAL);
112         }
113
114         if (init_data->constraints.boot_on)
115                 config->enabled_at_boot = true;
116
117         of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
118         of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay);
119
120         if (of_find_property(np, "vin-supply", NULL))
121                 config->input_supply = "vin";
122
123         return config;
124 }
125
126 static const struct regulator_ops fixed_voltage_ops = {
127 };
128
129 static const struct regulator_ops fixed_voltage_clkenabled_ops = {
130         .enable = reg_clock_enable,
131         .disable = reg_clock_disable,
132         .is_enabled = reg_clock_is_enabled,
133 };
134
135 static int reg_fixed_voltage_probe(struct platform_device *pdev)
136 {
137         struct device *dev = &pdev->dev;
138         struct fixed_voltage_config *config;
139         struct fixed_voltage_data *drvdata;
140         const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
141         struct regulator_config cfg = { };
142         enum gpiod_flags gflags;
143         int ret;
144
145         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
146                                GFP_KERNEL);
147         if (!drvdata)
148                 return -ENOMEM;
149
150         if (pdev->dev.of_node) {
151                 config = of_get_fixed_voltage_config(&pdev->dev,
152                                                      &drvdata->desc);
153                 if (IS_ERR(config))
154                         return PTR_ERR(config);
155         } else {
156                 config = dev_get_platdata(&pdev->dev);
157         }
158
159         if (!config)
160                 return -ENOMEM;
161
162         drvdata->desc.name = devm_kstrdup(&pdev->dev,
163                                           config->supply_name,
164                                           GFP_KERNEL);
165         if (drvdata->desc.name == NULL) {
166                 dev_err(&pdev->dev, "Failed to allocate supply name\n");
167                 return -ENOMEM;
168         }
169         drvdata->desc.type = REGULATOR_VOLTAGE;
170         drvdata->desc.owner = THIS_MODULE;
171
172         if (drvtype && drvtype->has_enable_clock) {
173                 drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
174
175                 drvdata->enable_clock = devm_clk_get(dev, NULL);
176                 if (IS_ERR(drvdata->enable_clock)) {
177                         dev_err(dev, "Can't get enable-clock from devicetree\n");
178                         return PTR_ERR(drvdata->enable_clock);
179                 }
180         } else {
181                 drvdata->desc.ops = &fixed_voltage_ops;
182         }
183
184         drvdata->desc.enable_time = config->startup_delay;
185         drvdata->desc.off_on_delay = config->off_on_delay;
186
187         if (config->input_supply) {
188                 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
189                                             config->input_supply,
190                                             GFP_KERNEL);
191                 if (!drvdata->desc.supply_name) {
192                         dev_err(&pdev->dev,
193                                 "Failed to allocate input supply\n");
194                         return -ENOMEM;
195                 }
196         }
197
198         if (config->microvolts)
199                 drvdata->desc.n_voltages = 1;
200
201         drvdata->desc.fixed_uV = config->microvolts;
202
203         /*
204          * The signal will be inverted by the GPIO core if flagged so in the
205          * descriptor.
206          */
207         if (config->enabled_at_boot)
208                 gflags = GPIOD_OUT_HIGH;
209         else
210                 gflags = GPIOD_OUT_LOW;
211
212         /*
213          * Some fixed regulators share the enable line between two
214          * regulators which makes it necessary to get a handle on the
215          * same descriptor for two different consumers. This will get
216          * the GPIO descriptor, but only the first call will initialize
217          * it so any flags such as inversion or open drain will only
218          * be set up by the first caller and assumed identical on the
219          * next caller.
220          *
221          * FIXME: find a better way to deal with this.
222          */
223         gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
224
225         /*
226          * Do not use devm* here: the regulator core takes over the
227          * lifecycle management of the GPIO descriptor.
228          */
229         cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
230         if (IS_ERR(cfg.ena_gpiod))
231                 return PTR_ERR(cfg.ena_gpiod);
232
233         cfg.dev = &pdev->dev;
234         cfg.init_data = config->init_data;
235         cfg.driver_data = drvdata;
236         cfg.of_node = pdev->dev.of_node;
237
238         drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
239                                                &cfg);
240         if (IS_ERR(drvdata->dev)) {
241                 ret = PTR_ERR(drvdata->dev);
242                 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
243                 return ret;
244         }
245
246         platform_set_drvdata(pdev, drvdata);
247
248         dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
249                 drvdata->desc.fixed_uV);
250
251         return 0;
252 }
253
254 #if defined(CONFIG_OF)
255 static const struct fixed_dev_type fixed_voltage_data = {
256         .has_enable_clock = false,
257 };
258
259 static const struct fixed_dev_type fixed_clkenable_data = {
260         .has_enable_clock = true,
261 };
262
263 static const struct of_device_id fixed_of_match[] = {
264         {
265                 .compatible = "regulator-fixed",
266                 .data = &fixed_voltage_data,
267         },
268         {
269                 .compatible = "regulator-fixed-clock",
270                 .data = &fixed_clkenable_data,
271         },
272         {
273         },
274 };
275 MODULE_DEVICE_TABLE(of, fixed_of_match);
276 #endif
277
278 static struct platform_driver regulator_fixed_voltage_driver = {
279         .probe          = reg_fixed_voltage_probe,
280         .driver         = {
281                 .name           = "reg-fixed-voltage",
282                 .of_match_table = of_match_ptr(fixed_of_match),
283         },
284 };
285
286 static int __init regulator_fixed_voltage_init(void)
287 {
288         return platform_driver_register(&regulator_fixed_voltage_driver);
289 }
290 subsys_initcall(regulator_fixed_voltage_init);
291
292 static void __exit regulator_fixed_voltage_exit(void)
293 {
294         platform_driver_unregister(&regulator_fixed_voltage_driver);
295 }
296 module_exit(regulator_fixed_voltage_exit);
297
298 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
299 MODULE_DESCRIPTION("Fixed voltage regulator");
300 MODULE_LICENSE("GPL");
301 MODULE_ALIAS("platform:reg-fixed-voltage");