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4b74ff65 MB |
1 | /* |
2 | * fixed.c | |
3 | * | |
4 | * Copyright 2008 Wolfson Microelectronics PLC. | |
5 | * | |
6 | * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> | |
7 | * | |
86d9884b RQ |
8 | * Copyright (c) 2009 Nokia Corporation |
9 | * Roger Quadros <ext-roger.quadros@nokia.com> | |
10 | * | |
4b74ff65 MB |
11 | * This program is free software; you can redistribute it and/or |
12 | * modify it under the terms of the GNU General Public License as | |
13 | * published by the Free Software Foundation; either version 2 of the | |
14 | * License, or (at your option) any later version. | |
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> | |
65602c32 | 23 | #include <linux/module.h> |
4b74ff65 MB |
24 | #include <linux/platform_device.h> |
25 | #include <linux/regulator/driver.h> | |
26 | #include <linux/regulator/fixed.h> | |
86d9884b | 27 | #include <linux/gpio.h> |
5a0e3ad6 | 28 | #include <linux/slab.h> |
cef49102 RN |
29 | #include <linux/of.h> |
30 | #include <linux/of_gpio.h> | |
31 | #include <linux/regulator/of_regulator.h> | |
32 | #include <linux/regulator/machine.h> | |
4b74ff65 MB |
33 | |
34 | struct fixed_voltage_data { | |
35 | struct regulator_desc desc; | |
36 | struct regulator_dev *dev; | |
37 | int microvolts; | |
86d9884b | 38 | int gpio; |
eda79a30 | 39 | unsigned startup_delay; |
8ab3343d DT |
40 | bool enable_high; |
41 | bool is_enabled; | |
4b74ff65 MB |
42 | }; |
43 | ||
cef49102 RN |
44 | |
45 | /** | |
46 | * of_get_fixed_voltage_config - extract fixed_voltage_config structure info | |
47 | * @dev: device requesting for fixed_voltage_config | |
48 | * | |
49 | * Populates fixed_voltage_config structure by extracting data from device | |
50 | * tree node, returns a pointer to the populated structure of NULL if memory | |
51 | * alloc fails. | |
52 | */ | |
bc91396b AL |
53 | static struct fixed_voltage_config * |
54 | of_get_fixed_voltage_config(struct device *dev) | |
cef49102 RN |
55 | { |
56 | struct fixed_voltage_config *config; | |
57 | struct device_node *np = dev->of_node; | |
58 | const __be32 *delay; | |
59 | struct regulator_init_data *init_data; | |
60 | ||
61 | config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), | |
62 | GFP_KERNEL); | |
63 | if (!config) | |
f141822b | 64 | return ERR_PTR(-ENOMEM); |
cef49102 | 65 | |
d9a861cc | 66 | config->init_data = of_get_regulator_init_data(dev, dev->of_node); |
4b864af1 | 67 | if (!config->init_data) |
f141822b | 68 | return ERR_PTR(-EINVAL); |
4b864af1 | 69 | |
cef49102 | 70 | init_data = config->init_data; |
0c437c4a | 71 | init_data->constraints.apply_uV = 0; |
cef49102 RN |
72 | |
73 | config->supply_name = init_data->constraints.name; | |
74 | if (init_data->constraints.min_uV == init_data->constraints.max_uV) { | |
75 | config->microvolts = init_data->constraints.min_uV; | |
76 | } else { | |
77 | dev_err(dev, | |
78 | "Fixed regulator specified with variable voltages\n"); | |
f141822b | 79 | return ERR_PTR(-EINVAL); |
cef49102 RN |
80 | } |
81 | ||
82 | if (init_data->constraints.boot_on) | |
83 | config->enabled_at_boot = true; | |
84 | ||
85 | config->gpio = of_get_named_gpio(np, "gpio", 0); | |
f141822b SW |
86 | /* |
87 | * of_get_named_gpio() currently returns ENODEV rather than | |
88 | * EPROBE_DEFER. This code attempts to be compatible with both | |
89 | * for now; the ENODEV check can be removed once the API is fixed. | |
90 | * of_get_named_gpio() doesn't differentiate between a missing | |
91 | * property (which would be fine here, since the GPIO is optional) | |
92 | * and some other error. Patches have been posted for both issues. | |
93 | * Once they are check in, we should replace this with: | |
94 | * if (config->gpio < 0 && config->gpio != -ENOENT) | |
95 | */ | |
96 | if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER)) | |
97 | return ERR_PTR(-EPROBE_DEFER); | |
98 | ||
cef49102 RN |
99 | delay = of_get_property(np, "startup-delay-us", NULL); |
100 | if (delay) | |
101 | config->startup_delay = be32_to_cpu(*delay); | |
102 | ||
103 | if (of_find_property(np, "enable-active-high", NULL)) | |
104 | config->enable_high = true; | |
105 | ||
9a50dba5 LD |
106 | if (of_find_property(np, "gpio-open-drain", NULL)) |
107 | config->gpio_is_open_drain = true; | |
108 | ||
cef49102 RN |
109 | return config; |
110 | } | |
111 | ||
4b74ff65 MB |
112 | static int fixed_voltage_is_enabled(struct regulator_dev *dev) |
113 | { | |
86d9884b RQ |
114 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
115 | ||
116 | return data->is_enabled; | |
4b74ff65 MB |
117 | } |
118 | ||
119 | static int fixed_voltage_enable(struct regulator_dev *dev) | |
120 | { | |
86d9884b RQ |
121 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
122 | ||
9d442061 MB |
123 | gpio_set_value_cansleep(data->gpio, data->enable_high); |
124 | data->is_enabled = true; | |
86d9884b RQ |
125 | |
126 | return 0; | |
127 | } | |
128 | ||
129 | static int fixed_voltage_disable(struct regulator_dev *dev) | |
130 | { | |
131 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
132 | ||
9d442061 MB |
133 | gpio_set_value_cansleep(data->gpio, !data->enable_high); |
134 | data->is_enabled = false; | |
86d9884b | 135 | |
4b74ff65 MB |
136 | return 0; |
137 | } | |
138 | ||
17133dc8 MB |
139 | static int fixed_voltage_enable_time(struct regulator_dev *dev) |
140 | { | |
141 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
142 | ||
143 | return data->startup_delay; | |
144 | } | |
145 | ||
4b74ff65 MB |
146 | static int fixed_voltage_get_voltage(struct regulator_dev *dev) |
147 | { | |
148 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
149 | ||
aebe4958 MB |
150 | if (data->microvolts) |
151 | return data->microvolts; | |
152 | else | |
153 | return -EINVAL; | |
4b74ff65 MB |
154 | } |
155 | ||
9035cefc MB |
156 | static int fixed_voltage_list_voltage(struct regulator_dev *dev, |
157 | unsigned selector) | |
158 | { | |
159 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
160 | ||
161 | if (selector != 0) | |
162 | return -EINVAL; | |
163 | ||
164 | return data->microvolts; | |
165 | } | |
166 | ||
9d442061 | 167 | static struct regulator_ops fixed_voltage_gpio_ops = { |
4b74ff65 MB |
168 | .is_enabled = fixed_voltage_is_enabled, |
169 | .enable = fixed_voltage_enable, | |
86d9884b | 170 | .disable = fixed_voltage_disable, |
17133dc8 | 171 | .enable_time = fixed_voltage_enable_time, |
4b74ff65 | 172 | .get_voltage = fixed_voltage_get_voltage, |
9035cefc | 173 | .list_voltage = fixed_voltage_list_voltage, |
4b74ff65 MB |
174 | }; |
175 | ||
9d442061 MB |
176 | static struct regulator_ops fixed_voltage_ops = { |
177 | .get_voltage = fixed_voltage_get_voltage, | |
178 | .list_voltage = fixed_voltage_list_voltage, | |
179 | }; | |
180 | ||
8ab3343d | 181 | static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev) |
4b74ff65 | 182 | { |
22d881c0 | 183 | struct fixed_voltage_config *config; |
4b74ff65 | 184 | struct fixed_voltage_data *drvdata; |
c172708d | 185 | struct regulator_config cfg = { }; |
4b74ff65 MB |
186 | int ret; |
187 | ||
f141822b | 188 | if (pdev->dev.of_node) { |
cef49102 | 189 | config = of_get_fixed_voltage_config(&pdev->dev); |
f141822b SW |
190 | if (IS_ERR(config)) |
191 | return PTR_ERR(config); | |
192 | } else { | |
22d881c0 | 193 | config = pdev->dev.platform_data; |
f141822b | 194 | } |
22d881c0 AL |
195 | |
196 | if (!config) | |
197 | return -ENOMEM; | |
cef49102 | 198 | |
c45bb35f MB |
199 | drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data), |
200 | GFP_KERNEL); | |
4b74ff65 | 201 | if (drvdata == NULL) { |
c53ad7fe | 202 | dev_err(&pdev->dev, "Failed to allocate device data\n"); |
4b74ff65 MB |
203 | ret = -ENOMEM; |
204 | goto err; | |
205 | } | |
206 | ||
207 | drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL); | |
208 | if (drvdata->desc.name == NULL) { | |
c53ad7fe | 209 | dev_err(&pdev->dev, "Failed to allocate supply name\n"); |
4b74ff65 MB |
210 | ret = -ENOMEM; |
211 | goto err; | |
212 | } | |
213 | drvdata->desc.type = REGULATOR_VOLTAGE; | |
214 | drvdata->desc.owner = THIS_MODULE; | |
1c37f8a8 SH |
215 | |
216 | if (config->microvolts) | |
217 | drvdata->desc.n_voltages = 1; | |
4b74ff65 MB |
218 | |
219 | drvdata->microvolts = config->microvolts; | |
86d9884b | 220 | drvdata->gpio = config->gpio; |
eda79a30 | 221 | drvdata->startup_delay = config->startup_delay; |
86d9884b RQ |
222 | |
223 | if (gpio_is_valid(config->gpio)) { | |
a4d9f179 | 224 | int gpio_flag; |
86d9884b RQ |
225 | drvdata->enable_high = config->enable_high; |
226 | ||
227 | /* FIXME: Remove below print warning | |
228 | * | |
229 | * config->gpio must be set to -EINVAL by platform code if | |
230 | * GPIO control is not required. However, early adopters | |
231 | * not requiring GPIO control may forget to initialize | |
232 | * config->gpio to -EINVAL. This will cause GPIO 0 to be used | |
233 | * for GPIO control. | |
234 | * | |
235 | * This warning will be removed once there are a couple of users | |
236 | * for this driver. | |
237 | */ | |
238 | if (!config->gpio) | |
239 | dev_warn(&pdev->dev, | |
240 | "using GPIO 0 for regulator enable control\n"); | |
241 | ||
a4d9f179 LD |
242 | /* |
243 | * set output direction without changing state | |
86d9884b RQ |
244 | * to prevent glitch |
245 | */ | |
246 | drvdata->is_enabled = config->enabled_at_boot; | |
247 | ret = drvdata->is_enabled ? | |
248 | config->enable_high : !config->enable_high; | |
a4d9f179 LD |
249 | gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; |
250 | ||
251 | if (config->gpio_is_open_drain) | |
252 | gpio_flag |= GPIOF_OPEN_DRAIN; | |
86d9884b | 253 | |
a4d9f179 LD |
254 | ret = gpio_request_one(config->gpio, gpio_flag, |
255 | config->supply_name); | |
86d9884b RQ |
256 | if (ret) { |
257 | dev_err(&pdev->dev, | |
a4d9f179 | 258 | "Could not obtain regulator enable GPIO %d: %d\n", |
86d9884b | 259 | config->gpio, ret); |
a4d9f179 | 260 | goto err_name; |
86d9884b RQ |
261 | } |
262 | ||
9d442061 MB |
263 | drvdata->desc.ops = &fixed_voltage_gpio_ops; |
264 | ||
86d9884b | 265 | } else { |
9d442061 | 266 | drvdata->desc.ops = &fixed_voltage_ops; |
86d9884b | 267 | } |
4b74ff65 | 268 | |
c172708d MB |
269 | cfg.dev = &pdev->dev; |
270 | cfg.init_data = config->init_data; | |
271 | cfg.driver_data = drvdata; | |
272 | cfg.of_node = pdev->dev.of_node; | |
273 | ||
274 | drvdata->dev = regulator_register(&drvdata->desc, &cfg); | |
4b74ff65 MB |
275 | if (IS_ERR(drvdata->dev)) { |
276 | ret = PTR_ERR(drvdata->dev); | |
c53ad7fe | 277 | dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); |
86d9884b | 278 | goto err_gpio; |
4b74ff65 MB |
279 | } |
280 | ||
281 | platform_set_drvdata(pdev, drvdata); | |
282 | ||
283 | dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, | |
284 | drvdata->microvolts); | |
285 | ||
286 | return 0; | |
287 | ||
86d9884b RQ |
288 | err_gpio: |
289 | if (gpio_is_valid(config->gpio)) | |
290 | gpio_free(config->gpio); | |
4b74ff65 MB |
291 | err_name: |
292 | kfree(drvdata->desc.name); | |
293 | err: | |
4b74ff65 MB |
294 | return ret; |
295 | } | |
296 | ||
8ab3343d | 297 | static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev) |
4b74ff65 MB |
298 | { |
299 | struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev); | |
300 | ||
301 | regulator_unregister(drvdata->dev); | |
86d9884b RQ |
302 | if (gpio_is_valid(drvdata->gpio)) |
303 | gpio_free(drvdata->gpio); | |
80099c70 | 304 | kfree(drvdata->desc.name); |
86d9884b | 305 | |
4b74ff65 MB |
306 | return 0; |
307 | } | |
308 | ||
cef49102 RN |
309 | #if defined(CONFIG_OF) |
310 | static const struct of_device_id fixed_of_match[] __devinitconst = { | |
311 | { .compatible = "regulator-fixed", }, | |
312 | {}, | |
313 | }; | |
314 | MODULE_DEVICE_TABLE(of, fixed_of_match); | |
cef49102 RN |
315 | #endif |
316 | ||
4b74ff65 | 317 | static struct platform_driver regulator_fixed_voltage_driver = { |
8ab3343d DT |
318 | .probe = reg_fixed_voltage_probe, |
319 | .remove = __devexit_p(reg_fixed_voltage_remove), | |
4b74ff65 MB |
320 | .driver = { |
321 | .name = "reg-fixed-voltage", | |
8ab3343d | 322 | .owner = THIS_MODULE, |
abcfaf23 | 323 | .of_match_table = of_match_ptr(fixed_of_match), |
4b74ff65 MB |
324 | }, |
325 | }; | |
326 | ||
327 | static int __init regulator_fixed_voltage_init(void) | |
328 | { | |
329 | return platform_driver_register(®ulator_fixed_voltage_driver); | |
330 | } | |
5a1b22be | 331 | subsys_initcall(regulator_fixed_voltage_init); |
4b74ff65 MB |
332 | |
333 | static void __exit regulator_fixed_voltage_exit(void) | |
334 | { | |
335 | platform_driver_unregister(®ulator_fixed_voltage_driver); | |
336 | } | |
337 | module_exit(regulator_fixed_voltage_exit); | |
338 | ||
339 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); | |
340 | MODULE_DESCRIPTION("Fixed voltage regulator"); | |
341 | MODULE_LICENSE("GPL"); | |
38c53c89 | 342 | MODULE_ALIAS("platform:reg-fixed-voltage"); |