Merge remote-tracking branch 'regulator/topic/gpio' into regulator-next
[~shefty/rdma-dev.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 struct gpio_regulator_config *
136 of_get_gpio_regulator_config(struct device *dev, struct device_node *np)
137 {
138         struct gpio_regulator_config *config;
139         struct property *prop;
140         const char *regtype;
141         int proplen, gpio, i;
142
143         config = devm_kzalloc(dev,
144                         sizeof(struct gpio_regulator_config),
145                         GFP_KERNEL);
146         if (!config)
147                 return ERR_PTR(-ENOMEM);
148
149         config->init_data = of_get_regulator_init_data(dev, np);
150         if (!config->init_data)
151                 return ERR_PTR(-EINVAL);
152
153         config->supply_name = config->init_data->constraints.name;
154
155         if (of_property_read_bool(np, "enable-active-high"))
156                 config->enable_high = true;
157
158         if (of_property_read_bool(np, "enable-at-boot"))
159                 config->enabled_at_boot = true;
160
161         of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
162
163         config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
164
165         /* Fetch GPIOs. */
166         for (i = 0; ; i++)
167                 if (of_get_named_gpio(np, "gpios", i) < 0)
168                         break;
169         config->nr_gpios = i;
170
171         config->gpios = devm_kzalloc(dev,
172                                 sizeof(struct gpio) * config->nr_gpios,
173                                 GFP_KERNEL);
174         if (!config->gpios)
175                 return ERR_PTR(-ENOMEM);
176
177         for (i = 0; i < config->nr_gpios; i++) {
178                 gpio = of_get_named_gpio(np, "gpios", i);
179                 if (gpio < 0)
180                         break;
181                 config->gpios[i].gpio = gpio;
182         }
183
184         /* Fetch states. */
185         prop = of_find_property(np, "states", NULL);
186         if (!prop) {
187                 dev_err(dev, "No 'states' property found\n");
188                 return ERR_PTR(-EINVAL);
189         }
190
191         proplen = prop->length / sizeof(int);
192
193         config->states = devm_kzalloc(dev,
194                                 sizeof(struct gpio_regulator_state)
195                                 * (proplen / 2),
196                                 GFP_KERNEL);
197         if (!config->states)
198                 return ERR_PTR(-ENOMEM);
199
200         for (i = 0; i < proplen / 2; i++) {
201                 config->states[i].value =
202                         be32_to_cpup((int *)prop->value + (i * 2));
203                 config->states[i].gpios =
204                         be32_to_cpup((int *)prop->value + (i * 2 + 1));
205         }
206         config->nr_states = i;
207
208         of_property_read_string(np, "regulator-type", &regtype);
209
210         if (!strncmp("voltage", regtype, 7))
211                 config->type = REGULATOR_VOLTAGE;
212         else if (!strncmp("current", regtype, 7))
213                 config->type = REGULATOR_CURRENT;
214
215         return config;
216 }
217
218 static struct regulator_ops gpio_regulator_current_ops = {
219         .get_current_limit = gpio_regulator_get_value,
220         .set_current_limit = gpio_regulator_set_current_limit,
221 };
222
223 static int gpio_regulator_probe(struct platform_device *pdev)
224 {
225         struct gpio_regulator_config *config = pdev->dev.platform_data;
226         struct device_node *np = pdev->dev.of_node;
227         struct gpio_regulator_data *drvdata;
228         struct regulator_config cfg = { };
229         int ptr, ret, state;
230
231         if (np) {
232                 config = of_get_gpio_regulator_config(&pdev->dev, np);
233                 if (IS_ERR(config))
234                         return PTR_ERR(config);
235         }
236
237         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
238                                GFP_KERNEL);
239         if (drvdata == NULL) {
240                 dev_err(&pdev->dev, "Failed to allocate device data\n");
241                 return -ENOMEM;
242         }
243
244         drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
245         if (drvdata->desc.name == NULL) {
246                 dev_err(&pdev->dev, "Failed to allocate supply name\n");
247                 ret = -ENOMEM;
248                 goto err;
249         }
250
251         drvdata->gpios = kmemdup(config->gpios,
252                                  config->nr_gpios * sizeof(struct gpio),
253                                  GFP_KERNEL);
254         if (drvdata->gpios == NULL) {
255                 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
256                 ret = -ENOMEM;
257                 goto err_name;
258         }
259
260         drvdata->states = kmemdup(config->states,
261                                   config->nr_states *
262                                          sizeof(struct gpio_regulator_state),
263                                   GFP_KERNEL);
264         if (drvdata->states == NULL) {
265                 dev_err(&pdev->dev, "Failed to allocate state data\n");
266                 ret = -ENOMEM;
267                 goto err_memgpio;
268         }
269         drvdata->nr_states = config->nr_states;
270
271         drvdata->desc.owner = THIS_MODULE;
272         drvdata->desc.enable_time = config->startup_delay;
273
274         /* handle regulator type*/
275         switch (config->type) {
276         case REGULATOR_VOLTAGE:
277                 drvdata->desc.type = REGULATOR_VOLTAGE;
278                 drvdata->desc.ops = &gpio_regulator_voltage_ops;
279                 drvdata->desc.n_voltages = config->nr_states;
280                 break;
281         case REGULATOR_CURRENT:
282                 drvdata->desc.type = REGULATOR_CURRENT;
283                 drvdata->desc.ops = &gpio_regulator_current_ops;
284                 break;
285         default:
286                 dev_err(&pdev->dev, "No regulator type set\n");
287                 ret = -EINVAL;
288                 goto err_memgpio;
289                 break;
290         }
291
292         drvdata->nr_gpios = config->nr_gpios;
293         ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
294         if (ret) {
295                 dev_err(&pdev->dev,
296                    "Could not obtain regulator setting GPIOs: %d\n", ret);
297                 goto err_memstate;
298         }
299
300         /* build initial state from gpio init data. */
301         state = 0;
302         for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
303                 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
304                         state |= (1 << ptr);
305         }
306         drvdata->state = state;
307
308         cfg.dev = &pdev->dev;
309         cfg.init_data = config->init_data;
310         cfg.driver_data = drvdata;
311         cfg.of_node = np;
312
313         if (config->enable_gpio >= 0)
314                 cfg.ena_gpio = config->enable_gpio;
315         cfg.ena_gpio_invert = !config->enable_high;
316         if (config->enabled_at_boot) {
317                 if (config->enable_high)
318                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
319                 else
320                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
321         } else {
322                 if (config->enable_high)
323                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
324                 else
325                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
326         }
327
328         drvdata->dev = regulator_register(&drvdata->desc, &cfg);
329         if (IS_ERR(drvdata->dev)) {
330                 ret = PTR_ERR(drvdata->dev);
331                 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
332                 goto err_stategpio;
333         }
334
335         platform_set_drvdata(pdev, drvdata);
336
337         return 0;
338
339 err_stategpio:
340         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
341 err_memstate:
342         kfree(drvdata->states);
343 err_memgpio:
344         kfree(drvdata->gpios);
345 err_name:
346         kfree(drvdata->desc.name);
347 err:
348         return ret;
349 }
350
351 static int gpio_regulator_remove(struct platform_device *pdev)
352 {
353         struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
354
355         regulator_unregister(drvdata->dev);
356
357         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
358
359         kfree(drvdata->states);
360         kfree(drvdata->gpios);
361
362         kfree(drvdata->desc.name);
363
364         return 0;
365 }
366
367 #if defined(CONFIG_OF)
368 static const struct of_device_id regulator_gpio_of_match[] __devinitconst = {
369         { .compatible = "regulator-gpio", },
370         {},
371 };
372 #endif
373
374 static struct platform_driver gpio_regulator_driver = {
375         .probe          = gpio_regulator_probe,
376         .remove         = gpio_regulator_remove,
377         .driver         = {
378                 .name           = "gpio-regulator",
379                 .owner          = THIS_MODULE,
380                 .of_match_table = of_match_ptr(regulator_gpio_of_match),
381         },
382 };
383
384 static int __init gpio_regulator_init(void)
385 {
386         return platform_driver_register(&gpio_regulator_driver);
387 }
388 subsys_initcall(gpio_regulator_init);
389
390 static void __exit gpio_regulator_exit(void)
391 {
392         platform_driver_unregister(&gpio_regulator_driver);
393 }
394 module_exit(gpio_regulator_exit);
395
396 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
397 MODULE_DESCRIPTION("gpio voltage regulator");
398 MODULE_LICENSE("GPL");
399 MODULE_ALIAS("platform:gpio-regulator");