regulator: core: fix race condition in regulator_put()
[pandora-kernel.git] / drivers / regulator / wm8400-regulator.c
1 /*
2  * Regulator support for WM8400
3  *
4  * Copyright 2008 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of the
11  * License, or (at your option) any later version.
12  *
13  */
14
15 #include <linux/bug.h>
16 #include <linux/err.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/regulator/driver.h>
20 #include <linux/mfd/wm8400-private.h>
21
22 static int wm8400_ldo_is_enabled(struct regulator_dev *dev)
23 {
24         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
25         u16 val;
26
27         val = wm8400_reg_read(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev));
28         return (val & WM8400_LDO1_ENA) != 0;
29 }
30
31 static int wm8400_ldo_enable(struct regulator_dev *dev)
32 {
33         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
34
35         return wm8400_set_bits(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev),
36                                WM8400_LDO1_ENA, WM8400_LDO1_ENA);
37 }
38
39 static int wm8400_ldo_disable(struct regulator_dev *dev)
40 {
41         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
42
43         return wm8400_set_bits(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev),
44                                WM8400_LDO1_ENA, 0);
45 }
46
47 static int wm8400_ldo_list_voltage(struct regulator_dev *dev,
48                                    unsigned selector)
49 {
50         if (selector > WM8400_LDO1_VSEL_MASK)
51                 return -EINVAL;
52
53         if (selector < 15)
54                 return 900000 + (selector * 50000);
55         else
56                 return 1600000 + ((selector - 14) * 100000);
57 }
58
59 static int wm8400_ldo_get_voltage_sel(struct regulator_dev *dev)
60 {
61         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
62         u16 val;
63
64         val = wm8400_reg_read(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev));
65         val &= WM8400_LDO1_VSEL_MASK;
66
67         return val;
68 }
69
70 static int wm8400_ldo_set_voltage(struct regulator_dev *dev,
71                                   int min_uV, int max_uV, unsigned *selector)
72 {
73         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
74         u16 val;
75
76         if (min_uV < 900000 || min_uV > 3300000)
77                 return -EINVAL;
78
79         if (min_uV < 1700000) {
80                 /* Steps of 50mV from 900mV;  */
81                 val = (min_uV - 850001) / 50000;
82
83                 if ((val * 50000) + 900000 > max_uV)
84                         return -EINVAL;
85                 BUG_ON((val * 50000) + 900000 < min_uV);
86         } else {
87                 /* Steps of 100mV from 1700mV */
88                 val = ((min_uV - 1600001) / 100000);
89
90                 if ((val * 100000) + 1700000 > max_uV)
91                         return -EINVAL;
92                 BUG_ON((val * 100000) + 1700000 < min_uV);
93
94                 val += 0xf;
95         }
96
97         *selector = val;
98
99         return wm8400_set_bits(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev),
100                                WM8400_LDO1_VSEL_MASK, val);
101 }
102
103 static struct regulator_ops wm8400_ldo_ops = {
104         .is_enabled = wm8400_ldo_is_enabled,
105         .enable = wm8400_ldo_enable,
106         .disable = wm8400_ldo_disable,
107         .list_voltage = wm8400_ldo_list_voltage,
108         .get_voltage_sel = wm8400_ldo_get_voltage_sel,
109         .set_voltage = wm8400_ldo_set_voltage,
110 };
111
112 static int wm8400_dcdc_is_enabled(struct regulator_dev *dev)
113 {
114         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
115         int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
116         u16 val;
117
118         val = wm8400_reg_read(wm8400, WM8400_DCDC1_CONTROL_1 + offset);
119         return (val & WM8400_DC1_ENA) != 0;
120 }
121
122 static int wm8400_dcdc_enable(struct regulator_dev *dev)
123 {
124         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
125         int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
126
127         return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
128                                WM8400_DC1_ENA, WM8400_DC1_ENA);
129 }
130
131 static int wm8400_dcdc_disable(struct regulator_dev *dev)
132 {
133         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
134         int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
135
136         return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
137                                WM8400_DC1_ENA, 0);
138 }
139
140 static int wm8400_dcdc_list_voltage(struct regulator_dev *dev,
141                                     unsigned selector)
142 {
143         if (selector > WM8400_DC1_VSEL_MASK)
144                 return -EINVAL;
145
146         return 850000 + (selector * 25000);
147 }
148
149 static int wm8400_dcdc_get_voltage_sel(struct regulator_dev *dev)
150 {
151         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
152         u16 val;
153         int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
154
155         val = wm8400_reg_read(wm8400, WM8400_DCDC1_CONTROL_1 + offset);
156         val &= WM8400_DC1_VSEL_MASK;
157
158         return val;
159 }
160
161 static int wm8400_dcdc_set_voltage(struct regulator_dev *dev,
162                                    int min_uV, int max_uV, unsigned *selector)
163 {
164         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
165         u16 val;
166         int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
167
168         if (min_uV < 850000)
169                 return -EINVAL;
170
171         val = (min_uV - 825001) / 25000;
172
173         if (850000 + (25000 * val) > max_uV)
174                 return -EINVAL;
175         BUG_ON(850000 + (25000 * val) < min_uV);
176
177         *selector = val;
178
179         return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
180                                WM8400_DC1_VSEL_MASK, val);
181 }
182
183 static unsigned int wm8400_dcdc_get_mode(struct regulator_dev *dev)
184 {
185         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
186         int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
187         u16 data[2];
188         int ret;
189
190         ret = wm8400_block_read(wm8400, WM8400_DCDC1_CONTROL_1 + offset, 2,
191                                 data);
192         if (ret != 0)
193                 return 0;
194
195         /* Datasheet: hibernate */
196         if (data[0] & WM8400_DC1_SLEEP)
197                 return REGULATOR_MODE_STANDBY;
198
199         /* Datasheet: standby */
200         if (!(data[0] & WM8400_DC1_ACTIVE))
201                 return REGULATOR_MODE_IDLE;
202
203         /* Datasheet: active with or without force PWM */
204         if (data[1] & WM8400_DC1_FRC_PWM)
205                 return REGULATOR_MODE_FAST;
206         else
207                 return REGULATOR_MODE_NORMAL;
208 }
209
210 static int wm8400_dcdc_set_mode(struct regulator_dev *dev, unsigned int mode)
211 {
212         struct wm8400 *wm8400 = rdev_get_drvdata(dev);
213         int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
214         int ret;
215
216         switch (mode) {
217         case REGULATOR_MODE_FAST:
218                 /* Datasheet: active with force PWM */
219                 ret = wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_2 + offset,
220                                       WM8400_DC1_FRC_PWM, WM8400_DC1_FRC_PWM);
221                 if (ret != 0)
222                         return ret;
223
224                 return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
225                                        WM8400_DC1_ACTIVE | WM8400_DC1_SLEEP,
226                                        WM8400_DC1_ACTIVE);
227
228         case REGULATOR_MODE_NORMAL:
229                 /* Datasheet: active */
230                 ret = wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_2 + offset,
231                                       WM8400_DC1_FRC_PWM, 0);
232                 if (ret != 0)
233                         return ret;
234
235                 return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
236                                        WM8400_DC1_ACTIVE | WM8400_DC1_SLEEP,
237                                        WM8400_DC1_ACTIVE);
238
239         case REGULATOR_MODE_IDLE:
240                 /* Datasheet: standby */
241                 ret = wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
242                                       WM8400_DC1_ACTIVE, 0);
243                 if (ret != 0)
244                         return ret;
245                 return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
246                                        WM8400_DC1_SLEEP, 0);
247
248         default:
249                 return -EINVAL;
250         }
251 }
252
253 static unsigned int wm8400_dcdc_get_optimum_mode(struct regulator_dev *dev,
254                                                  int input_uV, int output_uV,
255                                                  int load_uA)
256 {
257         return REGULATOR_MODE_NORMAL;
258 }
259
260 static struct regulator_ops wm8400_dcdc_ops = {
261         .is_enabled = wm8400_dcdc_is_enabled,
262         .enable = wm8400_dcdc_enable,
263         .disable = wm8400_dcdc_disable,
264         .list_voltage = wm8400_dcdc_list_voltage,
265         .get_voltage_sel = wm8400_dcdc_get_voltage_sel,
266         .set_voltage = wm8400_dcdc_set_voltage,
267         .get_mode = wm8400_dcdc_get_mode,
268         .set_mode = wm8400_dcdc_set_mode,
269         .get_optimum_mode = wm8400_dcdc_get_optimum_mode,
270 };
271
272 static struct regulator_desc regulators[] = {
273         {
274                 .name = "LDO1",
275                 .id = WM8400_LDO1,
276                 .ops = &wm8400_ldo_ops,
277                 .n_voltages = WM8400_LDO1_VSEL_MASK + 1,
278                 .type = REGULATOR_VOLTAGE,
279                 .owner = THIS_MODULE,
280         },
281         {
282                 .name = "LDO2",
283                 .id = WM8400_LDO2,
284                 .ops = &wm8400_ldo_ops,
285                 .n_voltages = WM8400_LDO2_VSEL_MASK + 1,
286                 .type = REGULATOR_VOLTAGE,
287                 .owner = THIS_MODULE,
288         },
289         {
290                 .name = "LDO3",
291                 .id = WM8400_LDO3,
292                 .ops = &wm8400_ldo_ops,
293                 .n_voltages = WM8400_LDO3_VSEL_MASK + 1,
294                 .type = REGULATOR_VOLTAGE,
295                 .owner = THIS_MODULE,
296         },
297         {
298                 .name = "LDO4",
299                 .id = WM8400_LDO4,
300                 .ops = &wm8400_ldo_ops,
301                 .n_voltages = WM8400_LDO4_VSEL_MASK + 1,
302                 .type = REGULATOR_VOLTAGE,
303                 .owner = THIS_MODULE,
304         },
305         {
306                 .name = "DCDC1",
307                 .id = WM8400_DCDC1,
308                 .ops = &wm8400_dcdc_ops,
309                 .n_voltages = WM8400_DC1_VSEL_MASK + 1,
310                 .type = REGULATOR_VOLTAGE,
311                 .owner = THIS_MODULE,
312         },
313         {
314                 .name = "DCDC2",
315                 .id = WM8400_DCDC2,
316                 .ops = &wm8400_dcdc_ops,
317                 .n_voltages = WM8400_DC2_VSEL_MASK + 1,
318                 .type = REGULATOR_VOLTAGE,
319                 .owner = THIS_MODULE,
320         },
321 };
322
323 static int __devinit wm8400_regulator_probe(struct platform_device *pdev)
324 {
325         struct wm8400 *wm8400 = container_of(pdev, struct wm8400, regulators[pdev->id]);
326         struct regulator_dev *rdev;
327
328         rdev = regulator_register(&regulators[pdev->id], &pdev->dev,
329                                   pdev->dev.platform_data, wm8400);
330
331         if (IS_ERR(rdev))
332                 return PTR_ERR(rdev);
333
334         platform_set_drvdata(pdev, rdev);
335
336         return 0;
337 }
338
339 static int __devexit wm8400_regulator_remove(struct platform_device *pdev)
340 {
341         struct regulator_dev *rdev = platform_get_drvdata(pdev);
342
343         platform_set_drvdata(pdev, NULL);
344         regulator_unregister(rdev);
345
346         return 0;
347 }
348
349 static struct platform_driver wm8400_regulator_driver = {
350         .driver = {
351                 .name = "wm8400-regulator",
352         },
353         .probe = wm8400_regulator_probe,
354         .remove = __devexit_p(wm8400_regulator_remove),
355 };
356
357 /**
358  * wm8400_register_regulator - enable software control of a WM8400 regulator
359  *
360  * This function enables software control of a WM8400 regulator via
361  * the regulator API.  It is intended to be called from the
362  * platform_init() callback of the WM8400 MFD driver.
363  *
364  * @param dev      The WM8400 device to operate on.
365  * @param reg      The regulator to control.
366  * @param initdata Regulator initdata for the regulator.
367  */
368 int wm8400_register_regulator(struct device *dev, int reg,
369                               struct regulator_init_data *initdata)
370 {
371         struct wm8400 *wm8400 = dev_get_drvdata(dev);
372
373         if (wm8400->regulators[reg].name)
374                 return -EBUSY;
375
376         initdata->driver_data = wm8400;
377
378         wm8400->regulators[reg].name = "wm8400-regulator";
379         wm8400->regulators[reg].id = reg;
380         wm8400->regulators[reg].dev.parent = dev;
381         wm8400->regulators[reg].dev.platform_data = initdata;
382
383         return platform_device_register(&wm8400->regulators[reg]);
384 }
385 EXPORT_SYMBOL_GPL(wm8400_register_regulator);
386
387 static int __init wm8400_regulator_init(void)
388 {
389         return platform_driver_register(&wm8400_regulator_driver);
390 }
391 subsys_initcall(wm8400_regulator_init);
392
393 static void __exit wm8400_regulator_exit(void)
394 {
395         platform_driver_unregister(&wm8400_regulator_driver);
396 }
397 module_exit(wm8400_regulator_exit);
398
399 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
400 MODULE_DESCRIPTION("WM8400 regulator driver");
401 MODULE_LICENSE("GPL");
402 MODULE_ALIAS("platform:wm8400-regulator");