Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
[linux-2.6-microblaze.git] / drivers / regulator / gpio-regulator.c
1 /*
2  * gpio-regulator.c
3  *
4  * Copyright 2011 Heiko Stuebner <heiko@sntech.de>
5  *
6  * based on fixed.c
7  *
8  * Copyright 2008 Wolfson Microelectronics PLC.
9  *
10  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
11  *
12  * Copyright (c) 2009 Nokia Corporation
13  * Roger Quadros <ext-roger.quadros@nokia.com>
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License as
17  * published by the Free Software Foundation; either version 2 of the
18  * License, or (at your option) any later version.
19  *
20  * This is useful for systems with mixed controllable and
21  * non-controllable regulators, as well as for allowing testing on
22  * systems with no controllable regulators.
23  */
24
25 #include <linux/err.h>
26 #include <linux/mutex.h>
27 #include <linux/module.h>
28 #include <linux/platform_device.h>
29 #include <linux/regulator/driver.h>
30 #include <linux/regulator/machine.h>
31 #include <linux/regulator/of_regulator.h>
32 #include <linux/regulator/gpio-regulator.h>
33 #include <linux/gpio.h>
34 #include <linux/slab.h>
35 #include <linux/of.h>
36 #include <linux/of_gpio.h>
37
38 struct gpio_regulator_data {
39         struct regulator_desc desc;
40         struct regulator_dev *dev;
41
42         struct gpio *gpios;
43         int nr_gpios;
44
45         struct gpio_regulator_state *states;
46         int nr_states;
47
48         int state;
49 };
50
51 static int gpio_regulator_get_value(struct regulator_dev *dev)
52 {
53         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
54         int ptr;
55
56         for (ptr = 0; ptr < data->nr_states; ptr++)
57                 if (data->states[ptr].gpios == data->state)
58                         return data->states[ptr].value;
59
60         return -EINVAL;
61 }
62
63 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
64                                         int min_uV, int max_uV,
65                                         unsigned *selector)
66 {
67         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
68         int ptr, target = 0, state, best_val = INT_MAX;
69
70         for (ptr = 0; ptr < data->nr_states; ptr++)
71                 if (data->states[ptr].value < best_val &&
72                     data->states[ptr].value >= min_uV &&
73                     data->states[ptr].value <= max_uV) {
74                         target = data->states[ptr].gpios;
75                         best_val = data->states[ptr].value;
76                         if (selector)
77                                 *selector = ptr;
78                 }
79
80         if (best_val == INT_MAX)
81                 return -EINVAL;
82
83         for (ptr = 0; ptr < data->nr_gpios; ptr++) {
84                 state = (target & (1 << ptr)) >> ptr;
85                 gpio_set_value_cansleep(data->gpios[ptr].gpio, state);
86         }
87         data->state = target;
88
89         return 0;
90 }
91
92 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
93                                       unsigned selector)
94 {
95         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
96
97         if (selector >= data->nr_states)
98                 return -EINVAL;
99
100         return data->states[selector].value;
101 }
102
103 static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
104                                         int min_uA, int max_uA)
105 {
106         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
107         int ptr, target = 0, state, best_val = 0;
108
109         for (ptr = 0; ptr < data->nr_states; ptr++)
110                 if (data->states[ptr].value > best_val &&
111                     data->states[ptr].value >= min_uA &&
112                     data->states[ptr].value <= max_uA) {
113                         target = data->states[ptr].gpios;
114                         best_val = data->states[ptr].value;
115                 }
116
117         if (best_val == 0)
118                 return -EINVAL;
119
120         for (ptr = 0; ptr < data->nr_gpios; ptr++) {
121                 state = (target & (1 << ptr)) >> ptr;
122                 gpio_set_value_cansleep(data->gpios[ptr].gpio, state);
123         }
124         data->state = target;
125
126         return 0;
127 }
128
129 static struct regulator_ops gpio_regulator_voltage_ops = {
130         .get_voltage = gpio_regulator_get_value,
131         .set_voltage = gpio_regulator_set_voltage,
132         .list_voltage = gpio_regulator_list_voltage,
133 };
134
135 static struct gpio_regulator_config *
136 of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
137                              const struct regulator_desc *desc)
138 {
139         struct gpio_regulator_config *config;
140         const char *regtype;
141         int proplen, gpio, i;
142         int ret;
143
144         config = devm_kzalloc(dev,
145                         sizeof(struct gpio_regulator_config),
146                         GFP_KERNEL);
147         if (!config)
148                 return ERR_PTR(-ENOMEM);
149
150         config->init_data = of_get_regulator_init_data(dev, np, desc);
151         if (!config->init_data)
152                 return ERR_PTR(-EINVAL);
153
154         config->supply_name = config->init_data->constraints.name;
155
156         if (of_property_read_bool(np, "enable-active-high"))
157                 config->enable_high = true;
158
159         if (of_property_read_bool(np, "enable-at-boot"))
160                 config->enabled_at_boot = true;
161
162         of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
163
164         config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
165         if (config->enable_gpio < 0 && config->enable_gpio != -ENOENT)
166                 return ERR_PTR(config->enable_gpio);
167
168         /* Fetch GPIOs. - optional property*/
169         ret = of_gpio_count(np);
170         if ((ret < 0) && (ret != -ENOENT))
171                 return ERR_PTR(ret);
172
173         if (ret > 0) {
174                 config->nr_gpios = ret;
175                 config->gpios = devm_kcalloc(dev,
176                                         config->nr_gpios, sizeof(struct gpio),
177                                         GFP_KERNEL);
178                 if (!config->gpios)
179                         return ERR_PTR(-ENOMEM);
180
181                 proplen = of_property_count_u32_elems(np, "gpios-states");
182                 /* optional property */
183                 if (proplen < 0)
184                         proplen = 0;
185
186                 if (proplen > 0 && proplen != config->nr_gpios) {
187                         dev_warn(dev, "gpios <-> gpios-states mismatch\n");
188                         proplen = 0;
189                 }
190
191                 for (i = 0; i < config->nr_gpios; i++) {
192                         gpio = of_get_named_gpio(np, "gpios", i);
193                         if (gpio < 0) {
194                                 if (gpio != -ENOENT)
195                                         return ERR_PTR(gpio);
196                                 break;
197                         }
198                         config->gpios[i].gpio = gpio;
199                         config->gpios[i].label = config->supply_name;
200                         if (proplen > 0) {
201                                 of_property_read_u32_index(np, "gpios-states",
202                                                            i, &ret);
203                                 if (ret)
204                                         config->gpios[i].flags =
205                                                            GPIOF_OUT_INIT_HIGH;
206                         }
207                 }
208         }
209
210         /* Fetch states. */
211         proplen = of_property_count_u32_elems(np, "states");
212         if (proplen < 0) {
213                 dev_err(dev, "No 'states' property found\n");
214                 return ERR_PTR(-EINVAL);
215         }
216
217         config->states = devm_kcalloc(dev,
218                                 proplen / 2,
219                                 sizeof(struct gpio_regulator_state),
220                                 GFP_KERNEL);
221         if (!config->states)
222                 return ERR_PTR(-ENOMEM);
223
224         for (i = 0; i < proplen / 2; i++) {
225                 of_property_read_u32_index(np, "states", i * 2,
226                                            &config->states[i].value);
227                 of_property_read_u32_index(np, "states", i * 2 + 1,
228                                            &config->states[i].gpios);
229         }
230         config->nr_states = i;
231
232         config->type = REGULATOR_VOLTAGE;
233         ret = of_property_read_string(np, "regulator-type", &regtype);
234         if (ret >= 0) {
235                 if (!strncmp("voltage", regtype, 7))
236                         config->type = REGULATOR_VOLTAGE;
237                 else if (!strncmp("current", regtype, 7))
238                         config->type = REGULATOR_CURRENT;
239                 else
240                         dev_warn(dev, "Unknown regulator-type '%s'\n",
241                                  regtype);
242         }
243
244         return config;
245 }
246
247 static struct regulator_ops gpio_regulator_current_ops = {
248         .get_current_limit = gpio_regulator_get_value,
249         .set_current_limit = gpio_regulator_set_current_limit,
250 };
251
252 static int gpio_regulator_probe(struct platform_device *pdev)
253 {
254         struct gpio_regulator_config *config = dev_get_platdata(&pdev->dev);
255         struct device_node *np = pdev->dev.of_node;
256         struct gpio_regulator_data *drvdata;
257         struct regulator_config cfg = { };
258         int ptr, ret, state;
259
260         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
261                                GFP_KERNEL);
262         if (drvdata == NULL)
263                 return -ENOMEM;
264
265         if (np) {
266                 config = of_get_gpio_regulator_config(&pdev->dev, np,
267                                                       &drvdata->desc);
268                 if (IS_ERR(config))
269                         return PTR_ERR(config);
270         }
271
272         drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
273         if (drvdata->desc.name == NULL) {
274                 dev_err(&pdev->dev, "Failed to allocate supply name\n");
275                 return -ENOMEM;
276         }
277
278         if (config->nr_gpios != 0) {
279                 drvdata->gpios = kmemdup(config->gpios,
280                                          config->nr_gpios * sizeof(struct gpio),
281                                          GFP_KERNEL);
282                 if (drvdata->gpios == NULL) {
283                         dev_err(&pdev->dev, "Failed to allocate gpio data\n");
284                         ret = -ENOMEM;
285                         goto err_name;
286                 }
287
288                 drvdata->nr_gpios = config->nr_gpios;
289                 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
290                 if (ret) {
291                         if (ret != -EPROBE_DEFER)
292                                 dev_err(&pdev->dev,
293                                         "Could not obtain regulator setting GPIOs: %d\n",
294                                         ret);
295                         goto err_memgpio;
296                 }
297         }
298
299         drvdata->states = kmemdup(config->states,
300                                   config->nr_states *
301                                          sizeof(struct gpio_regulator_state),
302                                   GFP_KERNEL);
303         if (drvdata->states == NULL) {
304                 dev_err(&pdev->dev, "Failed to allocate state data\n");
305                 ret = -ENOMEM;
306                 goto err_stategpio;
307         }
308         drvdata->nr_states = config->nr_states;
309
310         drvdata->desc.owner = THIS_MODULE;
311         drvdata->desc.enable_time = config->startup_delay;
312
313         /* handle regulator type*/
314         switch (config->type) {
315         case REGULATOR_VOLTAGE:
316                 drvdata->desc.type = REGULATOR_VOLTAGE;
317                 drvdata->desc.ops = &gpio_regulator_voltage_ops;
318                 drvdata->desc.n_voltages = config->nr_states;
319                 break;
320         case REGULATOR_CURRENT:
321                 drvdata->desc.type = REGULATOR_CURRENT;
322                 drvdata->desc.ops = &gpio_regulator_current_ops;
323                 break;
324         default:
325                 dev_err(&pdev->dev, "No regulator type set\n");
326                 ret = -EINVAL;
327                 goto err_memstate;
328         }
329
330         /* build initial state from gpio init data. */
331         state = 0;
332         for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
333                 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
334                         state |= (1 << ptr);
335         }
336         drvdata->state = state;
337
338         cfg.dev = &pdev->dev;
339         cfg.init_data = config->init_data;
340         cfg.driver_data = drvdata;
341         cfg.of_node = np;
342
343         if (gpio_is_valid(config->enable_gpio)) {
344                 cfg.ena_gpio = config->enable_gpio;
345                 cfg.ena_gpio_initialized = true;
346         }
347         cfg.ena_gpio_invert = !config->enable_high;
348         if (config->enabled_at_boot) {
349                 if (config->enable_high)
350                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
351                 else
352                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
353         } else {
354                 if (config->enable_high)
355                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
356                 else
357                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
358         }
359
360         drvdata->dev = regulator_register(&drvdata->desc, &cfg);
361         if (IS_ERR(drvdata->dev)) {
362                 ret = PTR_ERR(drvdata->dev);
363                 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
364                 goto err_memstate;
365         }
366
367         platform_set_drvdata(pdev, drvdata);
368
369         return 0;
370
371 err_memstate:
372         kfree(drvdata->states);
373 err_stategpio:
374         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
375 err_memgpio:
376         kfree(drvdata->gpios);
377 err_name:
378         kfree(drvdata->desc.name);
379         return ret;
380 }
381
382 static int gpio_regulator_remove(struct platform_device *pdev)
383 {
384         struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
385
386         regulator_unregister(drvdata->dev);
387
388         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
389
390         kfree(drvdata->states);
391         kfree(drvdata->gpios);
392
393         kfree(drvdata->desc.name);
394
395         return 0;
396 }
397
398 #if defined(CONFIG_OF)
399 static const struct of_device_id regulator_gpio_of_match[] = {
400         { .compatible = "regulator-gpio", },
401         {},
402 };
403 MODULE_DEVICE_TABLE(of, regulator_gpio_of_match);
404 #endif
405
406 static struct platform_driver gpio_regulator_driver = {
407         .probe          = gpio_regulator_probe,
408         .remove         = gpio_regulator_remove,
409         .driver         = {
410                 .name           = "gpio-regulator",
411                 .of_match_table = of_match_ptr(regulator_gpio_of_match),
412         },
413 };
414
415 static int __init gpio_regulator_init(void)
416 {
417         return platform_driver_register(&gpio_regulator_driver);
418 }
419 subsys_initcall(gpio_regulator_init);
420
421 static void __exit gpio_regulator_exit(void)
422 {
423         platform_driver_unregister(&gpio_regulator_driver);
424 }
425 module_exit(gpio_regulator_exit);
426
427 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
428 MODULE_DESCRIPTION("gpio voltage regulator");
429 MODULE_LICENSE("GPL");
430 MODULE_ALIAS("platform:gpio-regulator");