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