Merge branches 'pm-opp', 'pm-misc', 'pm-avs' and 'pm-tools'
[linux-2.6-microblaze.git] / drivers / regulator / gpio-regulator.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * gpio-regulator.c
4  *
5  * Copyright 2011 Heiko Stuebner <heiko@sntech.de>
6  *
7  * based on fixed.c
8  *
9  * Copyright 2008 Wolfson Microelectronics PLC.
10  *
11  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
12  *
13  * Copyright (c) 2009 Nokia Corporation
14  * Roger Quadros <ext-roger.quadros@nokia.com>
15  *
16  * This is useful for systems with mixed controllable and
17  * non-controllable regulators, as well as for allowing testing on
18  * systems with no controllable regulators.
19  */
20
21 #include <linux/err.h>
22 #include <linux/mutex.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/regulator/driver.h>
26 #include <linux/regulator/machine.h>
27 #include <linux/regulator/of_regulator.h>
28 #include <linux/regulator/gpio-regulator.h>
29 #include <linux/gpio/consumer.h>
30 #include <linux/slab.h>
31 #include <linux/of.h>
32
33 struct gpio_regulator_data {
34         struct regulator_desc desc;
35
36         struct gpio_desc **gpiods;
37         int nr_gpios;
38
39         struct gpio_regulator_state *states;
40         int nr_states;
41
42         int state;
43 };
44
45 static int gpio_regulator_get_value(struct regulator_dev *dev)
46 {
47         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
48         int ptr;
49
50         for (ptr = 0; ptr < data->nr_states; ptr++)
51                 if (data->states[ptr].gpios == data->state)
52                         return data->states[ptr].value;
53
54         return -EINVAL;
55 }
56
57 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
58                                         int min_uV, int max_uV,
59                                         unsigned *selector)
60 {
61         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
62         int ptr, target = 0, state, best_val = INT_MAX;
63
64         for (ptr = 0; ptr < data->nr_states; ptr++)
65                 if (data->states[ptr].value < best_val &&
66                     data->states[ptr].value >= min_uV &&
67                     data->states[ptr].value <= max_uV) {
68                         target = data->states[ptr].gpios;
69                         best_val = data->states[ptr].value;
70                         if (selector)
71                                 *selector = ptr;
72                 }
73
74         if (best_val == INT_MAX)
75                 return -EINVAL;
76
77         for (ptr = 0; ptr < data->nr_gpios; ptr++) {
78                 state = (target & (1 << ptr)) >> ptr;
79                 gpiod_set_value_cansleep(data->gpiods[ptr], state);
80         }
81         data->state = target;
82
83         return 0;
84 }
85
86 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
87                                       unsigned selector)
88 {
89         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
90
91         if (selector >= data->nr_states)
92                 return -EINVAL;
93
94         return data->states[selector].value;
95 }
96
97 static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
98                                         int min_uA, int max_uA)
99 {
100         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
101         int ptr, target = 0, state, best_val = 0;
102
103         for (ptr = 0; ptr < data->nr_states; ptr++)
104                 if (data->states[ptr].value > best_val &&
105                     data->states[ptr].value >= min_uA &&
106                     data->states[ptr].value <= max_uA) {
107                         target = data->states[ptr].gpios;
108                         best_val = data->states[ptr].value;
109                 }
110
111         if (best_val == 0)
112                 return -EINVAL;
113
114         for (ptr = 0; ptr < data->nr_gpios; ptr++) {
115                 state = (target & (1 << ptr)) >> ptr;
116                 gpiod_set_value_cansleep(data->gpiods[ptr], state);
117         }
118         data->state = target;
119
120         return 0;
121 }
122
123 static const struct regulator_ops gpio_regulator_voltage_ops = {
124         .get_voltage = gpio_regulator_get_value,
125         .set_voltage = gpio_regulator_set_voltage,
126         .list_voltage = gpio_regulator_list_voltage,
127 };
128
129 static struct gpio_regulator_config *
130 of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
131                              const struct regulator_desc *desc)
132 {
133         struct gpio_regulator_config *config;
134         const char *regtype;
135         int proplen, i;
136         int ngpios;
137         int ret;
138
139         config = devm_kzalloc(dev,
140                         sizeof(struct gpio_regulator_config),
141                         GFP_KERNEL);
142         if (!config)
143                 return ERR_PTR(-ENOMEM);
144
145         config->init_data = of_get_regulator_init_data(dev, np, desc);
146         if (!config->init_data)
147                 return ERR_PTR(-EINVAL);
148
149         config->supply_name = config->init_data->constraints.name;
150
151         if (of_property_read_bool(np, "enable-at-boot"))
152                 config->enabled_at_boot = true;
153
154         of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
155
156         /* Fetch GPIO init levels */
157         ngpios = gpiod_count(dev, NULL);
158         if (ngpios > 0) {
159                 config->gflags = devm_kzalloc(dev,
160                                               sizeof(enum gpiod_flags)
161                                               * ngpios,
162                                               GFP_KERNEL);
163                 if (!config->gflags)
164                         return ERR_PTR(-ENOMEM);
165
166                 for (i = 0; i < ngpios; i++) {
167                         u32 val;
168
169                         ret = of_property_read_u32_index(np, "gpios-states", i,
170                                                          &val);
171
172                         /* Default to high per specification */
173                         if (ret)
174                                 config->gflags[i] = GPIOD_OUT_HIGH;
175                         else
176                                 config->gflags[i] =
177                                         val ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
178                 }
179         }
180         config->ngpios = ngpios;
181
182         /* Fetch states. */
183         proplen = of_property_count_u32_elems(np, "states");
184         if (proplen < 0) {
185                 dev_err(dev, "No 'states' property found\n");
186                 return ERR_PTR(-EINVAL);
187         }
188
189         config->states = devm_kcalloc(dev,
190                                 proplen / 2,
191                                 sizeof(struct gpio_regulator_state),
192                                 GFP_KERNEL);
193         if (!config->states)
194                 return ERR_PTR(-ENOMEM);
195
196         for (i = 0; i < proplen / 2; i++) {
197                 of_property_read_u32_index(np, "states", i * 2,
198                                            &config->states[i].value);
199                 of_property_read_u32_index(np, "states", i * 2 + 1,
200                                            &config->states[i].gpios);
201         }
202         config->nr_states = i;
203
204         config->type = REGULATOR_VOLTAGE;
205         ret = of_property_read_string(np, "regulator-type", &regtype);
206         if (ret >= 0) {
207                 if (!strncmp("voltage", regtype, 7))
208                         config->type = REGULATOR_VOLTAGE;
209                 else if (!strncmp("current", regtype, 7))
210                         config->type = REGULATOR_CURRENT;
211                 else
212                         dev_warn(dev, "Unknown regulator-type '%s'\n",
213                                  regtype);
214         }
215
216         return config;
217 }
218
219 static const struct regulator_ops gpio_regulator_current_ops = {
220         .get_current_limit = gpio_regulator_get_value,
221         .set_current_limit = gpio_regulator_set_current_limit,
222 };
223
224 static int gpio_regulator_probe(struct platform_device *pdev)
225 {
226         struct device *dev = &pdev->dev;
227         struct gpio_regulator_config *config = dev_get_platdata(dev);
228         struct device_node *np = dev->of_node;
229         struct gpio_regulator_data *drvdata;
230         struct regulator_config cfg = { };
231         struct regulator_dev *rdev;
232         enum gpiod_flags gflags;
233         int ptr, ret, state, i;
234
235         drvdata = devm_kzalloc(dev, sizeof(struct gpio_regulator_data),
236                                GFP_KERNEL);
237         if (drvdata == NULL)
238                 return -ENOMEM;
239
240         if (np) {
241                 config = of_get_gpio_regulator_config(dev, np,
242                                                       &drvdata->desc);
243                 if (IS_ERR(config))
244                         return PTR_ERR(config);
245         }
246
247         drvdata->desc.name = devm_kstrdup(dev, config->supply_name, GFP_KERNEL);
248         if (drvdata->desc.name == NULL) {
249                 dev_err(dev, "Failed to allocate supply name\n");
250                 return -ENOMEM;
251         }
252
253         drvdata->gpiods = devm_kzalloc(dev, sizeof(struct gpio_desc *),
254                                        GFP_KERNEL);
255         if (!drvdata->gpiods)
256                 return -ENOMEM;
257         for (i = 0; i < config->ngpios; i++) {
258                 drvdata->gpiods[i] = devm_gpiod_get_index(dev,
259                                                           NULL,
260                                                           i,
261                                                           config->gflags[i]);
262                 if (IS_ERR(drvdata->gpiods[i]))
263                         return PTR_ERR(drvdata->gpiods[i]);
264                 /* This is good to know */
265                 gpiod_set_consumer_name(drvdata->gpiods[i], drvdata->desc.name);
266         }
267         drvdata->nr_gpios = config->ngpios;
268
269         drvdata->states = devm_kmemdup(dev,
270                                        config->states,
271                                        config->nr_states *
272                                        sizeof(struct gpio_regulator_state),
273                                        GFP_KERNEL);
274         if (drvdata->states == NULL) {
275                 dev_err(dev, "Failed to allocate state data\n");
276                 return -ENOMEM;
277         }
278         drvdata->nr_states = config->nr_states;
279
280         drvdata->desc.owner = THIS_MODULE;
281         drvdata->desc.enable_time = config->startup_delay;
282
283         /* handle regulator type*/
284         switch (config->type) {
285         case REGULATOR_VOLTAGE:
286                 drvdata->desc.type = REGULATOR_VOLTAGE;
287                 drvdata->desc.ops = &gpio_regulator_voltage_ops;
288                 drvdata->desc.n_voltages = config->nr_states;
289                 break;
290         case REGULATOR_CURRENT:
291                 drvdata->desc.type = REGULATOR_CURRENT;
292                 drvdata->desc.ops = &gpio_regulator_current_ops;
293                 break;
294         default:
295                 dev_err(dev, "No regulator type set\n");
296                 return -EINVAL;
297         }
298
299         /* build initial state from gpio init data. */
300         state = 0;
301         for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
302                 if (config->gflags[ptr] == GPIOD_OUT_HIGH)
303                         state |= (1 << ptr);
304         }
305         drvdata->state = state;
306
307         cfg.dev = dev;
308         cfg.init_data = config->init_data;
309         cfg.driver_data = drvdata;
310         cfg.of_node = np;
311
312         /*
313          * The signal will be inverted by the GPIO core if flagged so in the
314          * decriptor.
315          */
316         if (config->enabled_at_boot)
317                 gflags = GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
318         else
319                 gflags = GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
320
321         cfg.ena_gpiod = gpiod_get_optional(dev, "enable", gflags);
322         if (IS_ERR(cfg.ena_gpiod))
323                 return PTR_ERR(cfg.ena_gpiod);
324
325         rdev = devm_regulator_register(dev, &drvdata->desc, &cfg);
326         if (IS_ERR(rdev)) {
327                 ret = PTR_ERR(rdev);
328                 dev_err(dev, "Failed to register regulator: %d\n", ret);
329                 return ret;
330         }
331
332         platform_set_drvdata(pdev, drvdata);
333
334         return 0;
335 }
336
337 #if defined(CONFIG_OF)
338 static const struct of_device_id regulator_gpio_of_match[] = {
339         { .compatible = "regulator-gpio", },
340         {},
341 };
342 MODULE_DEVICE_TABLE(of, regulator_gpio_of_match);
343 #endif
344
345 static struct platform_driver gpio_regulator_driver = {
346         .probe          = gpio_regulator_probe,
347         .driver         = {
348                 .name           = "gpio-regulator",
349                 .of_match_table = of_match_ptr(regulator_gpio_of_match),
350         },
351 };
352
353 static int __init gpio_regulator_init(void)
354 {
355         return platform_driver_register(&gpio_regulator_driver);
356 }
357 subsys_initcall(gpio_regulator_init);
358
359 static void __exit gpio_regulator_exit(void)
360 {
361         platform_driver_unregister(&gpio_regulator_driver);
362 }
363 module_exit(gpio_regulator_exit);
364
365 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
366 MODULE_DESCRIPTION("gpio voltage regulator");
367 MODULE_LICENSE("GPL");
368 MODULE_ALIAS("platform:gpio-regulator");