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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> |
eda79a30 | 28 | #include <linux/delay.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
cef49102 RN |
30 | #include <linux/of.h> |
31 | #include <linux/of_gpio.h> | |
32 | #include <linux/regulator/of_regulator.h> | |
33 | #include <linux/regulator/machine.h> | |
4b74ff65 MB |
34 | |
35 | struct fixed_voltage_data { | |
36 | struct regulator_desc desc; | |
37 | struct regulator_dev *dev; | |
38 | int microvolts; | |
86d9884b | 39 | int gpio; |
eda79a30 | 40 | unsigned startup_delay; |
8ab3343d DT |
41 | bool enable_high; |
42 | bool is_enabled; | |
4b74ff65 MB |
43 | }; |
44 | ||
cef49102 RN |
45 | |
46 | /** | |
47 | * of_get_fixed_voltage_config - extract fixed_voltage_config structure info | |
48 | * @dev: device requesting for fixed_voltage_config | |
49 | * | |
50 | * Populates fixed_voltage_config structure by extracting data from device | |
51 | * tree node, returns a pointer to the populated structure of NULL if memory | |
52 | * alloc fails. | |
53 | */ | |
54 | struct fixed_voltage_config *of_get_fixed_voltage_config(struct device *dev) | |
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) | |
64 | return NULL; | |
65 | ||
66 | config->init_data = of_get_regulator_init_data(dev); | |
67 | init_data = config->init_data; | |
68 | ||
69 | config->supply_name = init_data->constraints.name; | |
70 | if (init_data->constraints.min_uV == init_data->constraints.max_uV) { | |
71 | config->microvolts = init_data->constraints.min_uV; | |
72 | } else { | |
73 | dev_err(dev, | |
74 | "Fixed regulator specified with variable voltages\n"); | |
75 | return NULL; | |
76 | } | |
77 | ||
78 | if (init_data->constraints.boot_on) | |
79 | config->enabled_at_boot = true; | |
80 | ||
81 | config->gpio = of_get_named_gpio(np, "gpio", 0); | |
82 | delay = of_get_property(np, "startup-delay-us", NULL); | |
83 | if (delay) | |
84 | config->startup_delay = be32_to_cpu(*delay); | |
85 | ||
86 | if (of_find_property(np, "enable-active-high", NULL)) | |
87 | config->enable_high = true; | |
88 | ||
89 | return config; | |
90 | } | |
91 | ||
4b74ff65 MB |
92 | static int fixed_voltage_is_enabled(struct regulator_dev *dev) |
93 | { | |
86d9884b RQ |
94 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
95 | ||
96 | return data->is_enabled; | |
4b74ff65 MB |
97 | } |
98 | ||
99 | static int fixed_voltage_enable(struct regulator_dev *dev) | |
100 | { | |
86d9884b RQ |
101 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
102 | ||
103 | if (gpio_is_valid(data->gpio)) { | |
104 | gpio_set_value_cansleep(data->gpio, data->enable_high); | |
8ab3343d | 105 | data->is_enabled = true; |
86d9884b RQ |
106 | } |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | static int fixed_voltage_disable(struct regulator_dev *dev) | |
112 | { | |
113 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
114 | ||
115 | if (gpio_is_valid(data->gpio)) { | |
116 | gpio_set_value_cansleep(data->gpio, !data->enable_high); | |
8ab3343d | 117 | data->is_enabled = false; |
86d9884b RQ |
118 | } |
119 | ||
4b74ff65 MB |
120 | return 0; |
121 | } | |
122 | ||
17133dc8 MB |
123 | static int fixed_voltage_enable_time(struct regulator_dev *dev) |
124 | { | |
125 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
126 | ||
127 | return data->startup_delay; | |
128 | } | |
129 | ||
4b74ff65 MB |
130 | static int fixed_voltage_get_voltage(struct regulator_dev *dev) |
131 | { | |
132 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
133 | ||
134 | return data->microvolts; | |
135 | } | |
136 | ||
9035cefc MB |
137 | static int fixed_voltage_list_voltage(struct regulator_dev *dev, |
138 | unsigned selector) | |
139 | { | |
140 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
141 | ||
142 | if (selector != 0) | |
143 | return -EINVAL; | |
144 | ||
145 | return data->microvolts; | |
146 | } | |
147 | ||
4b74ff65 MB |
148 | static struct regulator_ops fixed_voltage_ops = { |
149 | .is_enabled = fixed_voltage_is_enabled, | |
150 | .enable = fixed_voltage_enable, | |
86d9884b | 151 | .disable = fixed_voltage_disable, |
17133dc8 | 152 | .enable_time = fixed_voltage_enable_time, |
4b74ff65 | 153 | .get_voltage = fixed_voltage_get_voltage, |
9035cefc | 154 | .list_voltage = fixed_voltage_list_voltage, |
4b74ff65 MB |
155 | }; |
156 | ||
8ab3343d | 157 | static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev) |
4b74ff65 MB |
158 | { |
159 | struct fixed_voltage_config *config = pdev->dev.platform_data; | |
160 | struct fixed_voltage_data *drvdata; | |
161 | int ret; | |
162 | ||
cef49102 RN |
163 | if (pdev->dev.of_node) |
164 | config = of_get_fixed_voltage_config(&pdev->dev); | |
165 | ||
4b74ff65 MB |
166 | drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL); |
167 | if (drvdata == NULL) { | |
c53ad7fe | 168 | dev_err(&pdev->dev, "Failed to allocate device data\n"); |
4b74ff65 MB |
169 | ret = -ENOMEM; |
170 | goto err; | |
171 | } | |
172 | ||
173 | drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL); | |
174 | if (drvdata->desc.name == NULL) { | |
c53ad7fe | 175 | dev_err(&pdev->dev, "Failed to allocate supply name\n"); |
4b74ff65 MB |
176 | ret = -ENOMEM; |
177 | goto err; | |
178 | } | |
179 | drvdata->desc.type = REGULATOR_VOLTAGE; | |
180 | drvdata->desc.owner = THIS_MODULE; | |
9035cefc MB |
181 | drvdata->desc.ops = &fixed_voltage_ops; |
182 | drvdata->desc.n_voltages = 1; | |
4b74ff65 MB |
183 | |
184 | drvdata->microvolts = config->microvolts; | |
86d9884b | 185 | drvdata->gpio = config->gpio; |
eda79a30 | 186 | drvdata->startup_delay = config->startup_delay; |
86d9884b RQ |
187 | |
188 | if (gpio_is_valid(config->gpio)) { | |
189 | drvdata->enable_high = config->enable_high; | |
190 | ||
191 | /* FIXME: Remove below print warning | |
192 | * | |
193 | * config->gpio must be set to -EINVAL by platform code if | |
194 | * GPIO control is not required. However, early adopters | |
195 | * not requiring GPIO control may forget to initialize | |
196 | * config->gpio to -EINVAL. This will cause GPIO 0 to be used | |
197 | * for GPIO control. | |
198 | * | |
199 | * This warning will be removed once there are a couple of users | |
200 | * for this driver. | |
201 | */ | |
202 | if (!config->gpio) | |
203 | dev_warn(&pdev->dev, | |
204 | "using GPIO 0 for regulator enable control\n"); | |
205 | ||
206 | ret = gpio_request(config->gpio, config->supply_name); | |
207 | if (ret) { | |
208 | dev_err(&pdev->dev, | |
209 | "Could not obtain regulator enable GPIO %d: %d\n", | |
210 | config->gpio, ret); | |
211 | goto err_name; | |
212 | } | |
213 | ||
214 | /* set output direction without changing state | |
215 | * to prevent glitch | |
216 | */ | |
217 | drvdata->is_enabled = config->enabled_at_boot; | |
218 | ret = drvdata->is_enabled ? | |
219 | config->enable_high : !config->enable_high; | |
220 | ||
221 | ret = gpio_direction_output(config->gpio, ret); | |
222 | if (ret) { | |
223 | dev_err(&pdev->dev, | |
224 | "Could not configure regulator enable GPIO %d direction: %d\n", | |
225 | config->gpio, ret); | |
226 | goto err_gpio; | |
227 | } | |
228 | ||
229 | } else { | |
230 | /* Regulator without GPIO control is considered | |
231 | * always enabled | |
232 | */ | |
8ab3343d | 233 | drvdata->is_enabled = true; |
86d9884b | 234 | } |
4b74ff65 | 235 | |
bcf3402c | 236 | drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev, |
2c043bcb | 237 | config->init_data, drvdata, NULL); |
4b74ff65 MB |
238 | if (IS_ERR(drvdata->dev)) { |
239 | ret = PTR_ERR(drvdata->dev); | |
c53ad7fe | 240 | dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); |
86d9884b | 241 | goto err_gpio; |
4b74ff65 MB |
242 | } |
243 | ||
244 | platform_set_drvdata(pdev, drvdata); | |
245 | ||
246 | dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, | |
247 | drvdata->microvolts); | |
248 | ||
249 | return 0; | |
250 | ||
86d9884b RQ |
251 | err_gpio: |
252 | if (gpio_is_valid(config->gpio)) | |
253 | gpio_free(config->gpio); | |
4b74ff65 MB |
254 | err_name: |
255 | kfree(drvdata->desc.name); | |
256 | err: | |
257 | kfree(drvdata); | |
258 | return ret; | |
259 | } | |
260 | ||
8ab3343d | 261 | static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev) |
4b74ff65 MB |
262 | { |
263 | struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev); | |
264 | ||
265 | regulator_unregister(drvdata->dev); | |
86d9884b RQ |
266 | if (gpio_is_valid(drvdata->gpio)) |
267 | gpio_free(drvdata->gpio); | |
80099c70 DC |
268 | kfree(drvdata->desc.name); |
269 | kfree(drvdata); | |
86d9884b | 270 | |
4b74ff65 MB |
271 | return 0; |
272 | } | |
273 | ||
cef49102 RN |
274 | #if defined(CONFIG_OF) |
275 | static const struct of_device_id fixed_of_match[] __devinitconst = { | |
276 | { .compatible = "regulator-fixed", }, | |
277 | {}, | |
278 | }; | |
279 | MODULE_DEVICE_TABLE(of, fixed_of_match); | |
280 | #else | |
281 | #define fixed_of_match NULL | |
282 | #endif | |
283 | ||
4b74ff65 | 284 | static struct platform_driver regulator_fixed_voltage_driver = { |
8ab3343d DT |
285 | .probe = reg_fixed_voltage_probe, |
286 | .remove = __devexit_p(reg_fixed_voltage_remove), | |
4b74ff65 MB |
287 | .driver = { |
288 | .name = "reg-fixed-voltage", | |
8ab3343d | 289 | .owner = THIS_MODULE, |
cef49102 | 290 | .of_match_table = fixed_of_match, |
4b74ff65 MB |
291 | }, |
292 | }; | |
293 | ||
294 | static int __init regulator_fixed_voltage_init(void) | |
295 | { | |
296 | return platform_driver_register(®ulator_fixed_voltage_driver); | |
297 | } | |
5a1b22be | 298 | subsys_initcall(regulator_fixed_voltage_init); |
4b74ff65 MB |
299 | |
300 | static void __exit regulator_fixed_voltage_exit(void) | |
301 | { | |
302 | platform_driver_unregister(®ulator_fixed_voltage_driver); | |
303 | } | |
304 | module_exit(regulator_fixed_voltage_exit); | |
305 | ||
306 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); | |
307 | MODULE_DESCRIPTION("Fixed voltage regulator"); | |
308 | MODULE_LICENSE("GPL"); | |
38c53c89 | 309 | MODULE_ALIAS("platform:reg-fixed-voltage"); |