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3f0292ae HS |
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> | |
ecc37edf | 27 | #include <linux/module.h> |
3f0292ae HS |
28 | #include <linux/platform_device.h> |
29 | #include <linux/regulator/driver.h> | |
30 | #include <linux/regulator/machine.h> | |
31 | #include <linux/regulator/gpio-regulator.h> | |
32 | #include <linux/gpio.h> | |
33 | #include <linux/delay.h> | |
34 | #include <linux/slab.h> | |
35 | ||
36 | struct gpio_regulator_data { | |
37 | struct regulator_desc desc; | |
38 | struct regulator_dev *dev; | |
39 | ||
40 | int enable_gpio; | |
41 | bool enable_high; | |
42 | bool is_enabled; | |
43 | unsigned startup_delay; | |
44 | ||
45 | struct gpio *gpios; | |
46 | int nr_gpios; | |
47 | ||
48 | struct gpio_regulator_state *states; | |
49 | int nr_states; | |
50 | ||
51 | int state; | |
52 | }; | |
53 | ||
54 | static int gpio_regulator_is_enabled(struct regulator_dev *dev) | |
55 | { | |
56 | struct gpio_regulator_data *data = rdev_get_drvdata(dev); | |
57 | ||
58 | return data->is_enabled; | |
59 | } | |
60 | ||
61 | static int gpio_regulator_enable(struct regulator_dev *dev) | |
62 | { | |
63 | struct gpio_regulator_data *data = rdev_get_drvdata(dev); | |
64 | ||
65 | if (gpio_is_valid(data->enable_gpio)) { | |
66 | gpio_set_value_cansleep(data->enable_gpio, data->enable_high); | |
67 | data->is_enabled = true; | |
68 | } | |
69 | ||
70 | return 0; | |
71 | } | |
72 | ||
73 | static int gpio_regulator_disable(struct regulator_dev *dev) | |
74 | { | |
75 | struct gpio_regulator_data *data = rdev_get_drvdata(dev); | |
76 | ||
77 | if (gpio_is_valid(data->enable_gpio)) { | |
78 | gpio_set_value_cansleep(data->enable_gpio, !data->enable_high); | |
79 | data->is_enabled = false; | |
80 | } | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | static int gpio_regulator_enable_time(struct regulator_dev *dev) | |
86 | { | |
87 | struct gpio_regulator_data *data = rdev_get_drvdata(dev); | |
88 | ||
89 | return data->startup_delay; | |
90 | } | |
91 | ||
92 | static int gpio_regulator_get_value(struct regulator_dev *dev) | |
93 | { | |
94 | struct gpio_regulator_data *data = rdev_get_drvdata(dev); | |
95 | int ptr; | |
96 | ||
97 | for (ptr = 0; ptr < data->nr_states; ptr++) | |
98 | if (data->states[ptr].gpios == data->state) | |
99 | return data->states[ptr].value; | |
100 | ||
101 | return -EINVAL; | |
102 | } | |
103 | ||
104 | static int gpio_regulator_set_value(struct regulator_dev *dev, | |
105 | int min, int max) | |
106 | { | |
107 | struct gpio_regulator_data *data = rdev_get_drvdata(dev); | |
108 | int ptr, target, state; | |
109 | ||
110 | target = -1; | |
111 | for (ptr = 0; ptr < data->nr_states; ptr++) | |
112 | if (data->states[ptr].value >= min && | |
113 | data->states[ptr].value <= max) | |
114 | target = data->states[ptr].gpios; | |
115 | ||
116 | if (target < 0) | |
117 | return -EINVAL; | |
118 | ||
119 | for (ptr = 0; ptr < data->nr_gpios; ptr++) { | |
120 | state = (target & (1 << ptr)) >> ptr; | |
121 | gpio_set_value(data->gpios[ptr].gpio, state); | |
122 | } | |
123 | data->state = target; | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
128 | static int gpio_regulator_set_voltage(struct regulator_dev *dev, | |
129 | int min_uV, int max_uV, | |
130 | unsigned *selector) | |
131 | { | |
132 | return gpio_regulator_set_value(dev, min_uV, max_uV); | |
133 | } | |
134 | ||
135 | static int gpio_regulator_list_voltage(struct regulator_dev *dev, | |
136 | unsigned selector) | |
137 | { | |
138 | struct gpio_regulator_data *data = rdev_get_drvdata(dev); | |
139 | ||
140 | if (selector >= data->nr_states) | |
141 | return -EINVAL; | |
142 | ||
143 | return data->states[selector].value; | |
144 | } | |
145 | ||
146 | static int gpio_regulator_set_current_limit(struct regulator_dev *dev, | |
147 | int min_uA, int max_uA) | |
148 | { | |
149 | return gpio_regulator_set_value(dev, min_uA, max_uA); | |
150 | } | |
151 | ||
152 | static struct regulator_ops gpio_regulator_voltage_ops = { | |
153 | .is_enabled = gpio_regulator_is_enabled, | |
154 | .enable = gpio_regulator_enable, | |
155 | .disable = gpio_regulator_disable, | |
156 | .enable_time = gpio_regulator_enable_time, | |
157 | .get_voltage = gpio_regulator_get_value, | |
158 | .set_voltage = gpio_regulator_set_voltage, | |
159 | .list_voltage = gpio_regulator_list_voltage, | |
160 | }; | |
161 | ||
162 | static struct regulator_ops gpio_regulator_current_ops = { | |
163 | .is_enabled = gpio_regulator_is_enabled, | |
164 | .enable = gpio_regulator_enable, | |
165 | .disable = gpio_regulator_disable, | |
166 | .enable_time = gpio_regulator_enable_time, | |
167 | .get_current_limit = gpio_regulator_get_value, | |
168 | .set_current_limit = gpio_regulator_set_current_limit, | |
169 | }; | |
170 | ||
171 | static int __devinit gpio_regulator_probe(struct platform_device *pdev) | |
172 | { | |
173 | struct gpio_regulator_config *config = pdev->dev.platform_data; | |
174 | struct gpio_regulator_data *drvdata; | |
175 | int ptr, ret, state; | |
176 | ||
177 | drvdata = kzalloc(sizeof(struct gpio_regulator_data), GFP_KERNEL); | |
178 | if (drvdata == NULL) { | |
179 | dev_err(&pdev->dev, "Failed to allocate device data\n"); | |
180 | return -ENOMEM; | |
181 | } | |
182 | ||
183 | drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL); | |
184 | if (drvdata->desc.name == NULL) { | |
185 | dev_err(&pdev->dev, "Failed to allocate supply name\n"); | |
186 | ret = -ENOMEM; | |
187 | goto err; | |
188 | } | |
189 | ||
190 | drvdata->gpios = kmemdup(config->gpios, | |
191 | config->nr_gpios * sizeof(struct gpio), | |
192 | GFP_KERNEL); | |
193 | if (drvdata->gpios == NULL) { | |
194 | dev_err(&pdev->dev, "Failed to allocate gpio data\n"); | |
195 | ret = -ENOMEM; | |
196 | goto err_name; | |
197 | } | |
198 | ||
199 | drvdata->states = kmemdup(config->states, | |
200 | config->nr_states * | |
201 | sizeof(struct gpio_regulator_state), | |
202 | GFP_KERNEL); | |
203 | if (drvdata->states == NULL) { | |
204 | dev_err(&pdev->dev, "Failed to allocate state data\n"); | |
205 | ret = -ENOMEM; | |
206 | goto err_memgpio; | |
207 | } | |
208 | drvdata->nr_states = config->nr_states; | |
209 | ||
210 | drvdata->desc.owner = THIS_MODULE; | |
211 | ||
212 | /* handle regulator type*/ | |
213 | switch (config->type) { | |
214 | case REGULATOR_VOLTAGE: | |
215 | drvdata->desc.type = REGULATOR_VOLTAGE; | |
216 | drvdata->desc.ops = &gpio_regulator_voltage_ops; | |
217 | drvdata->desc.n_voltages = config->nr_states; | |
218 | break; | |
219 | case REGULATOR_CURRENT: | |
220 | drvdata->desc.type = REGULATOR_CURRENT; | |
221 | drvdata->desc.ops = &gpio_regulator_current_ops; | |
222 | break; | |
223 | default: | |
224 | dev_err(&pdev->dev, "No regulator type set\n"); | |
225 | ret = -EINVAL; | |
226 | goto err_memgpio; | |
227 | break; | |
228 | } | |
229 | ||
230 | drvdata->enable_gpio = config->enable_gpio; | |
231 | drvdata->startup_delay = config->startup_delay; | |
232 | ||
233 | if (gpio_is_valid(config->enable_gpio)) { | |
234 | drvdata->enable_high = config->enable_high; | |
235 | ||
236 | ret = gpio_request(config->enable_gpio, config->supply_name); | |
237 | if (ret) { | |
238 | dev_err(&pdev->dev, | |
239 | "Could not obtain regulator enable GPIO %d: %d\n", | |
240 | config->enable_gpio, ret); | |
241 | goto err_memstate; | |
242 | } | |
243 | ||
244 | /* set output direction without changing state | |
245 | * to prevent glitch | |
246 | */ | |
247 | if (config->enabled_at_boot) { | |
248 | drvdata->is_enabled = true; | |
249 | ret = gpio_direction_output(config->enable_gpio, | |
250 | config->enable_high); | |
251 | } else { | |
252 | drvdata->is_enabled = false; | |
253 | ret = gpio_direction_output(config->enable_gpio, | |
254 | !config->enable_high); | |
255 | } | |
256 | ||
257 | if (ret) { | |
258 | dev_err(&pdev->dev, | |
259 | "Could not configure regulator enable GPIO %d direction: %d\n", | |
260 | config->enable_gpio, ret); | |
261 | goto err_enablegpio; | |
262 | } | |
263 | } else { | |
264 | /* Regulator without GPIO control is considered | |
265 | * always enabled | |
266 | */ | |
267 | drvdata->is_enabled = true; | |
268 | } | |
269 | ||
270 | drvdata->nr_gpios = config->nr_gpios; | |
271 | ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios); | |
272 | if (ret) { | |
273 | dev_err(&pdev->dev, | |
274 | "Could not obtain regulator setting GPIOs: %d\n", ret); | |
275 | goto err_enablegpio; | |
276 | } | |
277 | ||
278 | /* build initial state from gpio init data. */ | |
279 | state = 0; | |
280 | for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) { | |
281 | if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH) | |
282 | state |= (1 << ptr); | |
283 | } | |
284 | drvdata->state = state; | |
285 | ||
286 | drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev, | |
15684347 | 287 | config->init_data, drvdata, NULL); |
3f0292ae HS |
288 | if (IS_ERR(drvdata->dev)) { |
289 | ret = PTR_ERR(drvdata->dev); | |
290 | dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); | |
291 | goto err_stategpio; | |
292 | } | |
293 | ||
294 | platform_set_drvdata(pdev, drvdata); | |
295 | ||
296 | return 0; | |
297 | ||
298 | err_stategpio: | |
299 | gpio_free_array(drvdata->gpios, drvdata->nr_gpios); | |
300 | err_enablegpio: | |
301 | if (gpio_is_valid(config->enable_gpio)) | |
302 | gpio_free(config->enable_gpio); | |
303 | err_memstate: | |
304 | kfree(drvdata->states); | |
305 | err_memgpio: | |
306 | kfree(drvdata->gpios); | |
307 | err_name: | |
308 | kfree(drvdata->desc.name); | |
309 | err: | |
310 | kfree(drvdata); | |
311 | return ret; | |
312 | } | |
313 | ||
314 | static int __devexit gpio_regulator_remove(struct platform_device *pdev) | |
315 | { | |
316 | struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev); | |
317 | ||
318 | regulator_unregister(drvdata->dev); | |
319 | ||
320 | gpio_free_array(drvdata->gpios, drvdata->nr_gpios); | |
321 | ||
322 | kfree(drvdata->states); | |
323 | kfree(drvdata->gpios); | |
324 | ||
325 | if (gpio_is_valid(drvdata->enable_gpio)) | |
326 | gpio_free(drvdata->enable_gpio); | |
327 | ||
328 | kfree(drvdata->desc.name); | |
329 | kfree(drvdata); | |
330 | ||
331 | return 0; | |
332 | } | |
333 | ||
334 | static struct platform_driver gpio_regulator_driver = { | |
335 | .probe = gpio_regulator_probe, | |
336 | .remove = __devexit_p(gpio_regulator_remove), | |
337 | .driver = { | |
338 | .name = "gpio-regulator", | |
339 | .owner = THIS_MODULE, | |
340 | }, | |
341 | }; | |
342 | ||
343 | static int __init gpio_regulator_init(void) | |
344 | { | |
345 | return platform_driver_register(&gpio_regulator_driver); | |
346 | } | |
347 | subsys_initcall(gpio_regulator_init); | |
348 | ||
349 | static void __exit gpio_regulator_exit(void) | |
350 | { | |
351 | platform_driver_unregister(&gpio_regulator_driver); | |
352 | } | |
353 | module_exit(gpio_regulator_exit); | |
354 | ||
355 | MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>"); | |
356 | MODULE_DESCRIPTION("gpio voltage regulator"); | |
357 | MODULE_LICENSE("GPL"); | |
358 | MODULE_ALIAS("platform:gpio-regulator"); |