xref: /linux/drivers/regulator/core.c (revision f8324e20f8289dffc646d64366332e05eaacab25)
1 /*
2  * core.c  --  Voltage/Current Regulator framework.
3  *
4  * Copyright 2007, 2008 Wolfson Microelectronics PLC.
5  * Copyright 2008 SlimLogic Ltd.
6  *
7  * Author: Liam Girdwood <lrg@slimlogic.co.uk>
8  *
9  *  This program is free software; you can redistribute  it and/or modify it
10  *  under  the terms of  the GNU General  Public License as published by the
11  *  Free Software Foundation;  either version 2 of the  License, or (at your
12  *  option) any later version.
13  *
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/device.h>
19 #include <linux/slab.h>
20 #include <linux/err.h>
21 #include <linux/mutex.h>
22 #include <linux/suspend.h>
23 #include <linux/delay.h>
24 #include <linux/regulator/consumer.h>
25 #include <linux/regulator/driver.h>
26 #include <linux/regulator/machine.h>
27 
28 #include "dummy.h"
29 
30 #define REGULATOR_VERSION "0.5"
31 
32 static DEFINE_MUTEX(regulator_list_mutex);
33 static LIST_HEAD(regulator_list);
34 static LIST_HEAD(regulator_map_list);
35 static int has_full_constraints;
36 
37 /*
38  * struct regulator_map
39  *
40  * Used to provide symbolic supply names to devices.
41  */
42 struct regulator_map {
43 	struct list_head list;
44 	const char *dev_name;   /* The dev_name() for the consumer */
45 	const char *supply;
46 	struct regulator_dev *regulator;
47 };
48 
49 /*
50  * struct regulator
51  *
52  * One for each consumer device.
53  */
54 struct regulator {
55 	struct device *dev;
56 	struct list_head list;
57 	int uA_load;
58 	int min_uV;
59 	int max_uV;
60 	char *supply_name;
61 	struct device_attribute dev_attr;
62 	struct regulator_dev *rdev;
63 };
64 
65 static int _regulator_is_enabled(struct regulator_dev *rdev);
66 static int _regulator_disable(struct regulator_dev *rdev);
67 static int _regulator_get_voltage(struct regulator_dev *rdev);
68 static int _regulator_get_current_limit(struct regulator_dev *rdev);
69 static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
70 static void _notifier_call_chain(struct regulator_dev *rdev,
71 				  unsigned long event, void *data);
72 
73 static const char *rdev_get_name(struct regulator_dev *rdev)
74 {
75 	if (rdev->constraints && rdev->constraints->name)
76 		return rdev->constraints->name;
77 	else if (rdev->desc->name)
78 		return rdev->desc->name;
79 	else
80 		return "";
81 }
82 
83 /* gets the regulator for a given consumer device */
84 static struct regulator *get_device_regulator(struct device *dev)
85 {
86 	struct regulator *regulator = NULL;
87 	struct regulator_dev *rdev;
88 
89 	mutex_lock(&regulator_list_mutex);
90 	list_for_each_entry(rdev, &regulator_list, list) {
91 		mutex_lock(&rdev->mutex);
92 		list_for_each_entry(regulator, &rdev->consumer_list, list) {
93 			if (regulator->dev == dev) {
94 				mutex_unlock(&rdev->mutex);
95 				mutex_unlock(&regulator_list_mutex);
96 				return regulator;
97 			}
98 		}
99 		mutex_unlock(&rdev->mutex);
100 	}
101 	mutex_unlock(&regulator_list_mutex);
102 	return NULL;
103 }
104 
105 /* Platform voltage constraint check */
106 static int regulator_check_voltage(struct regulator_dev *rdev,
107 				   int *min_uV, int *max_uV)
108 {
109 	BUG_ON(*min_uV > *max_uV);
110 
111 	if (!rdev->constraints) {
112 		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
113 		       rdev_get_name(rdev));
114 		return -ENODEV;
115 	}
116 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE)) {
117 		printk(KERN_ERR "%s: operation not allowed for %s\n",
118 		       __func__, rdev_get_name(rdev));
119 		return -EPERM;
120 	}
121 
122 	if (*max_uV > rdev->constraints->max_uV)
123 		*max_uV = rdev->constraints->max_uV;
124 	if (*min_uV < rdev->constraints->min_uV)
125 		*min_uV = rdev->constraints->min_uV;
126 
127 	if (*min_uV > *max_uV)
128 		return -EINVAL;
129 
130 	return 0;
131 }
132 
133 /* current constraint check */
134 static int regulator_check_current_limit(struct regulator_dev *rdev,
135 					int *min_uA, int *max_uA)
136 {
137 	BUG_ON(*min_uA > *max_uA);
138 
139 	if (!rdev->constraints) {
140 		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
141 		       rdev_get_name(rdev));
142 		return -ENODEV;
143 	}
144 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_CURRENT)) {
145 		printk(KERN_ERR "%s: operation not allowed for %s\n",
146 		       __func__, rdev_get_name(rdev));
147 		return -EPERM;
148 	}
149 
150 	if (*max_uA > rdev->constraints->max_uA)
151 		*max_uA = rdev->constraints->max_uA;
152 	if (*min_uA < rdev->constraints->min_uA)
153 		*min_uA = rdev->constraints->min_uA;
154 
155 	if (*min_uA > *max_uA)
156 		return -EINVAL;
157 
158 	return 0;
159 }
160 
161 /* operating mode constraint check */
162 static int regulator_check_mode(struct regulator_dev *rdev, int mode)
163 {
164 	switch (mode) {
165 	case REGULATOR_MODE_FAST:
166 	case REGULATOR_MODE_NORMAL:
167 	case REGULATOR_MODE_IDLE:
168 	case REGULATOR_MODE_STANDBY:
169 		break;
170 	default:
171 		return -EINVAL;
172 	}
173 
174 	if (!rdev->constraints) {
175 		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
176 		       rdev_get_name(rdev));
177 		return -ENODEV;
178 	}
179 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_MODE)) {
180 		printk(KERN_ERR "%s: operation not allowed for %s\n",
181 		       __func__, rdev_get_name(rdev));
182 		return -EPERM;
183 	}
184 	if (!(rdev->constraints->valid_modes_mask & mode)) {
185 		printk(KERN_ERR "%s: invalid mode %x for %s\n",
186 		       __func__, mode, rdev_get_name(rdev));
187 		return -EINVAL;
188 	}
189 	return 0;
190 }
191 
192 /* dynamic regulator mode switching constraint check */
193 static int regulator_check_drms(struct regulator_dev *rdev)
194 {
195 	if (!rdev->constraints) {
196 		printk(KERN_ERR "%s: no constraints for %s\n", __func__,
197 		       rdev_get_name(rdev));
198 		return -ENODEV;
199 	}
200 	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS)) {
201 		printk(KERN_ERR "%s: operation not allowed for %s\n",
202 		       __func__, rdev_get_name(rdev));
203 		return -EPERM;
204 	}
205 	return 0;
206 }
207 
208 static ssize_t device_requested_uA_show(struct device *dev,
209 			     struct device_attribute *attr, char *buf)
210 {
211 	struct regulator *regulator;
212 
213 	regulator = get_device_regulator(dev);
214 	if (regulator == NULL)
215 		return 0;
216 
217 	return sprintf(buf, "%d\n", regulator->uA_load);
218 }
219 
220 static ssize_t regulator_uV_show(struct device *dev,
221 				struct device_attribute *attr, char *buf)
222 {
223 	struct regulator_dev *rdev = dev_get_drvdata(dev);
224 	ssize_t ret;
225 
226 	mutex_lock(&rdev->mutex);
227 	ret = sprintf(buf, "%d\n", _regulator_get_voltage(rdev));
228 	mutex_unlock(&rdev->mutex);
229 
230 	return ret;
231 }
232 static DEVICE_ATTR(microvolts, 0444, regulator_uV_show, NULL);
233 
234 static ssize_t regulator_uA_show(struct device *dev,
235 				struct device_attribute *attr, char *buf)
236 {
237 	struct regulator_dev *rdev = dev_get_drvdata(dev);
238 
239 	return sprintf(buf, "%d\n", _regulator_get_current_limit(rdev));
240 }
241 static DEVICE_ATTR(microamps, 0444, regulator_uA_show, NULL);
242 
243 static ssize_t regulator_name_show(struct device *dev,
244 			     struct device_attribute *attr, char *buf)
245 {
246 	struct regulator_dev *rdev = dev_get_drvdata(dev);
247 
248 	return sprintf(buf, "%s\n", rdev_get_name(rdev));
249 }
250 
251 static ssize_t regulator_print_opmode(char *buf, int mode)
252 {
253 	switch (mode) {
254 	case REGULATOR_MODE_FAST:
255 		return sprintf(buf, "fast\n");
256 	case REGULATOR_MODE_NORMAL:
257 		return sprintf(buf, "normal\n");
258 	case REGULATOR_MODE_IDLE:
259 		return sprintf(buf, "idle\n");
260 	case REGULATOR_MODE_STANDBY:
261 		return sprintf(buf, "standby\n");
262 	}
263 	return sprintf(buf, "unknown\n");
264 }
265 
266 static ssize_t regulator_opmode_show(struct device *dev,
267 				    struct device_attribute *attr, char *buf)
268 {
269 	struct regulator_dev *rdev = dev_get_drvdata(dev);
270 
271 	return regulator_print_opmode(buf, _regulator_get_mode(rdev));
272 }
273 static DEVICE_ATTR(opmode, 0444, regulator_opmode_show, NULL);
274 
275 static ssize_t regulator_print_state(char *buf, int state)
276 {
277 	if (state > 0)
278 		return sprintf(buf, "enabled\n");
279 	else if (state == 0)
280 		return sprintf(buf, "disabled\n");
281 	else
282 		return sprintf(buf, "unknown\n");
283 }
284 
285 static ssize_t regulator_state_show(struct device *dev,
286 				   struct device_attribute *attr, char *buf)
287 {
288 	struct regulator_dev *rdev = dev_get_drvdata(dev);
289 	ssize_t ret;
290 
291 	mutex_lock(&rdev->mutex);
292 	ret = regulator_print_state(buf, _regulator_is_enabled(rdev));
293 	mutex_unlock(&rdev->mutex);
294 
295 	return ret;
296 }
297 static DEVICE_ATTR(state, 0444, regulator_state_show, NULL);
298 
299 static ssize_t regulator_status_show(struct device *dev,
300 				   struct device_attribute *attr, char *buf)
301 {
302 	struct regulator_dev *rdev = dev_get_drvdata(dev);
303 	int status;
304 	char *label;
305 
306 	status = rdev->desc->ops->get_status(rdev);
307 	if (status < 0)
308 		return status;
309 
310 	switch (status) {
311 	case REGULATOR_STATUS_OFF:
312 		label = "off";
313 		break;
314 	case REGULATOR_STATUS_ON:
315 		label = "on";
316 		break;
317 	case REGULATOR_STATUS_ERROR:
318 		label = "error";
319 		break;
320 	case REGULATOR_STATUS_FAST:
321 		label = "fast";
322 		break;
323 	case REGULATOR_STATUS_NORMAL:
324 		label = "normal";
325 		break;
326 	case REGULATOR_STATUS_IDLE:
327 		label = "idle";
328 		break;
329 	case REGULATOR_STATUS_STANDBY:
330 		label = "standby";
331 		break;
332 	default:
333 		return -ERANGE;
334 	}
335 
336 	return sprintf(buf, "%s\n", label);
337 }
338 static DEVICE_ATTR(status, 0444, regulator_status_show, NULL);
339 
340 static ssize_t regulator_min_uA_show(struct device *dev,
341 				    struct device_attribute *attr, char *buf)
342 {
343 	struct regulator_dev *rdev = dev_get_drvdata(dev);
344 
345 	if (!rdev->constraints)
346 		return sprintf(buf, "constraint not defined\n");
347 
348 	return sprintf(buf, "%d\n", rdev->constraints->min_uA);
349 }
350 static DEVICE_ATTR(min_microamps, 0444, regulator_min_uA_show, NULL);
351 
352 static ssize_t regulator_max_uA_show(struct device *dev,
353 				    struct device_attribute *attr, char *buf)
354 {
355 	struct regulator_dev *rdev = dev_get_drvdata(dev);
356 
357 	if (!rdev->constraints)
358 		return sprintf(buf, "constraint not defined\n");
359 
360 	return sprintf(buf, "%d\n", rdev->constraints->max_uA);
361 }
362 static DEVICE_ATTR(max_microamps, 0444, regulator_max_uA_show, NULL);
363 
364 static ssize_t regulator_min_uV_show(struct device *dev,
365 				    struct device_attribute *attr, char *buf)
366 {
367 	struct regulator_dev *rdev = dev_get_drvdata(dev);
368 
369 	if (!rdev->constraints)
370 		return sprintf(buf, "constraint not defined\n");
371 
372 	return sprintf(buf, "%d\n", rdev->constraints->min_uV);
373 }
374 static DEVICE_ATTR(min_microvolts, 0444, regulator_min_uV_show, NULL);
375 
376 static ssize_t regulator_max_uV_show(struct device *dev,
377 				    struct device_attribute *attr, char *buf)
378 {
379 	struct regulator_dev *rdev = dev_get_drvdata(dev);
380 
381 	if (!rdev->constraints)
382 		return sprintf(buf, "constraint not defined\n");
383 
384 	return sprintf(buf, "%d\n", rdev->constraints->max_uV);
385 }
386 static DEVICE_ATTR(max_microvolts, 0444, regulator_max_uV_show, NULL);
387 
388 static ssize_t regulator_total_uA_show(struct device *dev,
389 				      struct device_attribute *attr, char *buf)
390 {
391 	struct regulator_dev *rdev = dev_get_drvdata(dev);
392 	struct regulator *regulator;
393 	int uA = 0;
394 
395 	mutex_lock(&rdev->mutex);
396 	list_for_each_entry(regulator, &rdev->consumer_list, list)
397 		uA += regulator->uA_load;
398 	mutex_unlock(&rdev->mutex);
399 	return sprintf(buf, "%d\n", uA);
400 }
401 static DEVICE_ATTR(requested_microamps, 0444, regulator_total_uA_show, NULL);
402 
403 static ssize_t regulator_num_users_show(struct device *dev,
404 				      struct device_attribute *attr, char *buf)
405 {
406 	struct regulator_dev *rdev = dev_get_drvdata(dev);
407 	return sprintf(buf, "%d\n", rdev->use_count);
408 }
409 
410 static ssize_t regulator_type_show(struct device *dev,
411 				  struct device_attribute *attr, char *buf)
412 {
413 	struct regulator_dev *rdev = dev_get_drvdata(dev);
414 
415 	switch (rdev->desc->type) {
416 	case REGULATOR_VOLTAGE:
417 		return sprintf(buf, "voltage\n");
418 	case REGULATOR_CURRENT:
419 		return sprintf(buf, "current\n");
420 	}
421 	return sprintf(buf, "unknown\n");
422 }
423 
424 static ssize_t regulator_suspend_mem_uV_show(struct device *dev,
425 				struct device_attribute *attr, char *buf)
426 {
427 	struct regulator_dev *rdev = dev_get_drvdata(dev);
428 
429 	return sprintf(buf, "%d\n", rdev->constraints->state_mem.uV);
430 }
431 static DEVICE_ATTR(suspend_mem_microvolts, 0444,
432 		regulator_suspend_mem_uV_show, NULL);
433 
434 static ssize_t regulator_suspend_disk_uV_show(struct device *dev,
435 				struct device_attribute *attr, char *buf)
436 {
437 	struct regulator_dev *rdev = dev_get_drvdata(dev);
438 
439 	return sprintf(buf, "%d\n", rdev->constraints->state_disk.uV);
440 }
441 static DEVICE_ATTR(suspend_disk_microvolts, 0444,
442 		regulator_suspend_disk_uV_show, NULL);
443 
444 static ssize_t regulator_suspend_standby_uV_show(struct device *dev,
445 				struct device_attribute *attr, char *buf)
446 {
447 	struct regulator_dev *rdev = dev_get_drvdata(dev);
448 
449 	return sprintf(buf, "%d\n", rdev->constraints->state_standby.uV);
450 }
451 static DEVICE_ATTR(suspend_standby_microvolts, 0444,
452 		regulator_suspend_standby_uV_show, NULL);
453 
454 static ssize_t regulator_suspend_mem_mode_show(struct device *dev,
455 				struct device_attribute *attr, char *buf)
456 {
457 	struct regulator_dev *rdev = dev_get_drvdata(dev);
458 
459 	return regulator_print_opmode(buf,
460 		rdev->constraints->state_mem.mode);
461 }
462 static DEVICE_ATTR(suspend_mem_mode, 0444,
463 		regulator_suspend_mem_mode_show, NULL);
464 
465 static ssize_t regulator_suspend_disk_mode_show(struct device *dev,
466 				struct device_attribute *attr, char *buf)
467 {
468 	struct regulator_dev *rdev = dev_get_drvdata(dev);
469 
470 	return regulator_print_opmode(buf,
471 		rdev->constraints->state_disk.mode);
472 }
473 static DEVICE_ATTR(suspend_disk_mode, 0444,
474 		regulator_suspend_disk_mode_show, NULL);
475 
476 static ssize_t regulator_suspend_standby_mode_show(struct device *dev,
477 				struct device_attribute *attr, char *buf)
478 {
479 	struct regulator_dev *rdev = dev_get_drvdata(dev);
480 
481 	return regulator_print_opmode(buf,
482 		rdev->constraints->state_standby.mode);
483 }
484 static DEVICE_ATTR(suspend_standby_mode, 0444,
485 		regulator_suspend_standby_mode_show, NULL);
486 
487 static ssize_t regulator_suspend_mem_state_show(struct device *dev,
488 				   struct device_attribute *attr, char *buf)
489 {
490 	struct regulator_dev *rdev = dev_get_drvdata(dev);
491 
492 	return regulator_print_state(buf,
493 			rdev->constraints->state_mem.enabled);
494 }
495 static DEVICE_ATTR(suspend_mem_state, 0444,
496 		regulator_suspend_mem_state_show, NULL);
497 
498 static ssize_t regulator_suspend_disk_state_show(struct device *dev,
499 				   struct device_attribute *attr, char *buf)
500 {
501 	struct regulator_dev *rdev = dev_get_drvdata(dev);
502 
503 	return regulator_print_state(buf,
504 			rdev->constraints->state_disk.enabled);
505 }
506 static DEVICE_ATTR(suspend_disk_state, 0444,
507 		regulator_suspend_disk_state_show, NULL);
508 
509 static ssize_t regulator_suspend_standby_state_show(struct device *dev,
510 				   struct device_attribute *attr, char *buf)
511 {
512 	struct regulator_dev *rdev = dev_get_drvdata(dev);
513 
514 	return regulator_print_state(buf,
515 			rdev->constraints->state_standby.enabled);
516 }
517 static DEVICE_ATTR(suspend_standby_state, 0444,
518 		regulator_suspend_standby_state_show, NULL);
519 
520 
521 /*
522  * These are the only attributes are present for all regulators.
523  * Other attributes are a function of regulator functionality.
524  */
525 static struct device_attribute regulator_dev_attrs[] = {
526 	__ATTR(name, 0444, regulator_name_show, NULL),
527 	__ATTR(num_users, 0444, regulator_num_users_show, NULL),
528 	__ATTR(type, 0444, regulator_type_show, NULL),
529 	__ATTR_NULL,
530 };
531 
532 static void regulator_dev_release(struct device *dev)
533 {
534 	struct regulator_dev *rdev = dev_get_drvdata(dev);
535 	kfree(rdev);
536 }
537 
538 static struct class regulator_class = {
539 	.name = "regulator",
540 	.dev_release = regulator_dev_release,
541 	.dev_attrs = regulator_dev_attrs,
542 };
543 
544 /* Calculate the new optimum regulator operating mode based on the new total
545  * consumer load. All locks held by caller */
546 static void drms_uA_update(struct regulator_dev *rdev)
547 {
548 	struct regulator *sibling;
549 	int current_uA = 0, output_uV, input_uV, err;
550 	unsigned int mode;
551 
552 	err = regulator_check_drms(rdev);
553 	if (err < 0 || !rdev->desc->ops->get_optimum_mode ||
554 	    !rdev->desc->ops->get_voltage || !rdev->desc->ops->set_mode)
555 		return;
556 
557 	/* get output voltage */
558 	output_uV = rdev->desc->ops->get_voltage(rdev);
559 	if (output_uV <= 0)
560 		return;
561 
562 	/* get input voltage */
563 	if (rdev->supply && rdev->supply->desc->ops->get_voltage)
564 		input_uV = rdev->supply->desc->ops->get_voltage(rdev->supply);
565 	else
566 		input_uV = rdev->constraints->input_uV;
567 	if (input_uV <= 0)
568 		return;
569 
570 	/* calc total requested load */
571 	list_for_each_entry(sibling, &rdev->consumer_list, list)
572 		current_uA += sibling->uA_load;
573 
574 	/* now get the optimum mode for our new total regulator load */
575 	mode = rdev->desc->ops->get_optimum_mode(rdev, input_uV,
576 						  output_uV, current_uA);
577 
578 	/* check the new mode is allowed */
579 	err = regulator_check_mode(rdev, mode);
580 	if (err == 0)
581 		rdev->desc->ops->set_mode(rdev, mode);
582 }
583 
584 static int suspend_set_state(struct regulator_dev *rdev,
585 	struct regulator_state *rstate)
586 {
587 	int ret = 0;
588 	bool can_set_state;
589 
590 	can_set_state = rdev->desc->ops->set_suspend_enable &&
591 		rdev->desc->ops->set_suspend_disable;
592 
593 	/* If we have no suspend mode configration don't set anything;
594 	 * only warn if the driver actually makes the suspend mode
595 	 * configurable.
596 	 */
597 	if (!rstate->enabled && !rstate->disabled) {
598 		if (can_set_state)
599 			printk(KERN_WARNING "%s: No configuration for %s\n",
600 			       __func__, rdev_get_name(rdev));
601 		return 0;
602 	}
603 
604 	if (rstate->enabled && rstate->disabled) {
605 		printk(KERN_ERR "%s: invalid configuration for %s\n",
606 		       __func__, rdev_get_name(rdev));
607 		return -EINVAL;
608 	}
609 
610 	if (!can_set_state) {
611 		printk(KERN_ERR "%s: no way to set suspend state\n",
612 			__func__);
613 		return -EINVAL;
614 	}
615 
616 	if (rstate->enabled)
617 		ret = rdev->desc->ops->set_suspend_enable(rdev);
618 	else
619 		ret = rdev->desc->ops->set_suspend_disable(rdev);
620 	if (ret < 0) {
621 		printk(KERN_ERR "%s: failed to enabled/disable\n", __func__);
622 		return ret;
623 	}
624 
625 	if (rdev->desc->ops->set_suspend_voltage && rstate->uV > 0) {
626 		ret = rdev->desc->ops->set_suspend_voltage(rdev, rstate->uV);
627 		if (ret < 0) {
628 			printk(KERN_ERR "%s: failed to set voltage\n",
629 				__func__);
630 			return ret;
631 		}
632 	}
633 
634 	if (rdev->desc->ops->set_suspend_mode && rstate->mode > 0) {
635 		ret = rdev->desc->ops->set_suspend_mode(rdev, rstate->mode);
636 		if (ret < 0) {
637 			printk(KERN_ERR "%s: failed to set mode\n", __func__);
638 			return ret;
639 		}
640 	}
641 	return ret;
642 }
643 
644 /* locks held by caller */
645 static int suspend_prepare(struct regulator_dev *rdev, suspend_state_t state)
646 {
647 	if (!rdev->constraints)
648 		return -EINVAL;
649 
650 	switch (state) {
651 	case PM_SUSPEND_STANDBY:
652 		return suspend_set_state(rdev,
653 			&rdev->constraints->state_standby);
654 	case PM_SUSPEND_MEM:
655 		return suspend_set_state(rdev,
656 			&rdev->constraints->state_mem);
657 	case PM_SUSPEND_MAX:
658 		return suspend_set_state(rdev,
659 			&rdev->constraints->state_disk);
660 	default:
661 		return -EINVAL;
662 	}
663 }
664 
665 static void print_constraints(struct regulator_dev *rdev)
666 {
667 	struct regulation_constraints *constraints = rdev->constraints;
668 	char buf[80] = "";
669 	int count = 0;
670 	int ret;
671 
672 	if (constraints->min_uV && constraints->max_uV) {
673 		if (constraints->min_uV == constraints->max_uV)
674 			count += sprintf(buf + count, "%d mV ",
675 					 constraints->min_uV / 1000);
676 		else
677 			count += sprintf(buf + count, "%d <--> %d mV ",
678 					 constraints->min_uV / 1000,
679 					 constraints->max_uV / 1000);
680 	}
681 
682 	if (!constraints->min_uV ||
683 	    constraints->min_uV != constraints->max_uV) {
684 		ret = _regulator_get_voltage(rdev);
685 		if (ret > 0)
686 			count += sprintf(buf + count, "at %d mV ", ret / 1000);
687 	}
688 
689 	if (constraints->min_uA && constraints->max_uA) {
690 		if (constraints->min_uA == constraints->max_uA)
691 			count += sprintf(buf + count, "%d mA ",
692 					 constraints->min_uA / 1000);
693 		else
694 			count += sprintf(buf + count, "%d <--> %d mA ",
695 					 constraints->min_uA / 1000,
696 					 constraints->max_uA / 1000);
697 	}
698 
699 	if (!constraints->min_uA ||
700 	    constraints->min_uA != constraints->max_uA) {
701 		ret = _regulator_get_current_limit(rdev);
702 		if (ret > 0)
703 			count += sprintf(buf + count, "at %d uA ", ret / 1000);
704 	}
705 
706 	if (constraints->valid_modes_mask & REGULATOR_MODE_FAST)
707 		count += sprintf(buf + count, "fast ");
708 	if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
709 		count += sprintf(buf + count, "normal ");
710 	if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
711 		count += sprintf(buf + count, "idle ");
712 	if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
713 		count += sprintf(buf + count, "standby");
714 
715 	printk(KERN_INFO "regulator: %s: %s\n", rdev_get_name(rdev), buf);
716 }
717 
718 static int machine_constraints_voltage(struct regulator_dev *rdev,
719 	struct regulation_constraints *constraints)
720 {
721 	struct regulator_ops *ops = rdev->desc->ops;
722 	const char *name = rdev_get_name(rdev);
723 	int ret;
724 
725 	/* do we need to apply the constraint voltage */
726 	if (rdev->constraints->apply_uV &&
727 		rdev->constraints->min_uV == rdev->constraints->max_uV &&
728 		ops->set_voltage) {
729 		ret = ops->set_voltage(rdev,
730 			rdev->constraints->min_uV, rdev->constraints->max_uV);
731 			if (ret < 0) {
732 				printk(KERN_ERR "%s: failed to apply %duV constraint to %s\n",
733 				       __func__,
734 				       rdev->constraints->min_uV, name);
735 				rdev->constraints = NULL;
736 				return ret;
737 			}
738 	}
739 
740 	/* constrain machine-level voltage specs to fit
741 	 * the actual range supported by this regulator.
742 	 */
743 	if (ops->list_voltage && rdev->desc->n_voltages) {
744 		int	count = rdev->desc->n_voltages;
745 		int	i;
746 		int	min_uV = INT_MAX;
747 		int	max_uV = INT_MIN;
748 		int	cmin = constraints->min_uV;
749 		int	cmax = constraints->max_uV;
750 
751 		/* it's safe to autoconfigure fixed-voltage supplies
752 		   and the constraints are used by list_voltage. */
753 		if (count == 1 && !cmin) {
754 			cmin = 1;
755 			cmax = INT_MAX;
756 			constraints->min_uV = cmin;
757 			constraints->max_uV = cmax;
758 		}
759 
760 		/* voltage constraints are optional */
761 		if ((cmin == 0) && (cmax == 0))
762 			return 0;
763 
764 		/* else require explicit machine-level constraints */
765 		if (cmin <= 0 || cmax <= 0 || cmax < cmin) {
766 			pr_err("%s: %s '%s' voltage constraints\n",
767 				       __func__, "invalid", name);
768 			return -EINVAL;
769 		}
770 
771 		/* initial: [cmin..cmax] valid, [min_uV..max_uV] not */
772 		for (i = 0; i < count; i++) {
773 			int	value;
774 
775 			value = ops->list_voltage(rdev, i);
776 			if (value <= 0)
777 				continue;
778 
779 			/* maybe adjust [min_uV..max_uV] */
780 			if (value >= cmin && value < min_uV)
781 				min_uV = value;
782 			if (value <= cmax && value > max_uV)
783 				max_uV = value;
784 		}
785 
786 		/* final: [min_uV..max_uV] valid iff constraints valid */
787 		if (max_uV < min_uV) {
788 			pr_err("%s: %s '%s' voltage constraints\n",
789 				       __func__, "unsupportable", name);
790 			return -EINVAL;
791 		}
792 
793 		/* use regulator's subset of machine constraints */
794 		if (constraints->min_uV < min_uV) {
795 			pr_debug("%s: override '%s' %s, %d -> %d\n",
796 				       __func__, name, "min_uV",
797 					constraints->min_uV, min_uV);
798 			constraints->min_uV = min_uV;
799 		}
800 		if (constraints->max_uV > max_uV) {
801 			pr_debug("%s: override '%s' %s, %d -> %d\n",
802 				       __func__, name, "max_uV",
803 					constraints->max_uV, max_uV);
804 			constraints->max_uV = max_uV;
805 		}
806 	}
807 
808 	return 0;
809 }
810 
811 /**
812  * set_machine_constraints - sets regulator constraints
813  * @rdev: regulator source
814  * @constraints: constraints to apply
815  *
816  * Allows platform initialisation code to define and constrain
817  * regulator circuits e.g. valid voltage/current ranges, etc.  NOTE:
818  * Constraints *must* be set by platform code in order for some
819  * regulator operations to proceed i.e. set_voltage, set_current_limit,
820  * set_mode.
821  */
822 static int set_machine_constraints(struct regulator_dev *rdev,
823 	struct regulation_constraints *constraints)
824 {
825 	int ret = 0;
826 	const char *name;
827 	struct regulator_ops *ops = rdev->desc->ops;
828 
829 	rdev->constraints = constraints;
830 
831 	name = rdev_get_name(rdev);
832 
833 	ret = machine_constraints_voltage(rdev, constraints);
834 	if (ret != 0)
835 		goto out;
836 
837 	/* do we need to setup our suspend state */
838 	if (constraints->initial_state) {
839 		ret = suspend_prepare(rdev, constraints->initial_state);
840 		if (ret < 0) {
841 			printk(KERN_ERR "%s: failed to set suspend state for %s\n",
842 			       __func__, name);
843 			rdev->constraints = NULL;
844 			goto out;
845 		}
846 	}
847 
848 	if (constraints->initial_mode) {
849 		if (!ops->set_mode) {
850 			printk(KERN_ERR "%s: no set_mode operation for %s\n",
851 			       __func__, name);
852 			ret = -EINVAL;
853 			goto out;
854 		}
855 
856 		ret = ops->set_mode(rdev, constraints->initial_mode);
857 		if (ret < 0) {
858 			printk(KERN_ERR
859 			       "%s: failed to set initial mode for %s: %d\n",
860 			       __func__, name, ret);
861 			goto out;
862 		}
863 	}
864 
865 	/* If the constraints say the regulator should be on at this point
866 	 * and we have control then make sure it is enabled.
867 	 */
868 	if ((constraints->always_on || constraints->boot_on) && ops->enable) {
869 		ret = ops->enable(rdev);
870 		if (ret < 0) {
871 			printk(KERN_ERR "%s: failed to enable %s\n",
872 			       __func__, name);
873 			rdev->constraints = NULL;
874 			goto out;
875 		}
876 	}
877 
878 	print_constraints(rdev);
879 out:
880 	return ret;
881 }
882 
883 /**
884  * set_supply - set regulator supply regulator
885  * @rdev: regulator name
886  * @supply_rdev: supply regulator name
887  *
888  * Called by platform initialisation code to set the supply regulator for this
889  * regulator. This ensures that a regulators supply will also be enabled by the
890  * core if it's child is enabled.
891  */
892 static int set_supply(struct regulator_dev *rdev,
893 	struct regulator_dev *supply_rdev)
894 {
895 	int err;
896 
897 	err = sysfs_create_link(&rdev->dev.kobj, &supply_rdev->dev.kobj,
898 				"supply");
899 	if (err) {
900 		printk(KERN_ERR
901 		       "%s: could not add device link %s err %d\n",
902 		       __func__, supply_rdev->dev.kobj.name, err);
903 		       goto out;
904 	}
905 	rdev->supply = supply_rdev;
906 	list_add(&rdev->slist, &supply_rdev->supply_list);
907 out:
908 	return err;
909 }
910 
911 /**
912  * set_consumer_device_supply: Bind a regulator to a symbolic supply
913  * @rdev:         regulator source
914  * @consumer_dev: device the supply applies to
915  * @consumer_dev_name: dev_name() string for device supply applies to
916  * @supply:       symbolic name for supply
917  *
918  * Allows platform initialisation code to map physical regulator
919  * sources to symbolic names for supplies for use by devices.  Devices
920  * should use these symbolic names to request regulators, avoiding the
921  * need to provide board-specific regulator names as platform data.
922  *
923  * Only one of consumer_dev and consumer_dev_name may be specified.
924  */
925 static int set_consumer_device_supply(struct regulator_dev *rdev,
926 	struct device *consumer_dev, const char *consumer_dev_name,
927 	const char *supply)
928 {
929 	struct regulator_map *node;
930 	int has_dev;
931 
932 	if (consumer_dev && consumer_dev_name)
933 		return -EINVAL;
934 
935 	if (!consumer_dev_name && consumer_dev)
936 		consumer_dev_name = dev_name(consumer_dev);
937 
938 	if (supply == NULL)
939 		return -EINVAL;
940 
941 	if (consumer_dev_name != NULL)
942 		has_dev = 1;
943 	else
944 		has_dev = 0;
945 
946 	list_for_each_entry(node, &regulator_map_list, list) {
947 		if (node->dev_name && consumer_dev_name) {
948 			if (strcmp(node->dev_name, consumer_dev_name) != 0)
949 				continue;
950 		} else if (node->dev_name || consumer_dev_name) {
951 			continue;
952 		}
953 
954 		if (strcmp(node->supply, supply) != 0)
955 			continue;
956 
957 		dev_dbg(consumer_dev, "%s/%s is '%s' supply; fail %s/%s\n",
958 				dev_name(&node->regulator->dev),
959 				node->regulator->desc->name,
960 				supply,
961 				dev_name(&rdev->dev), rdev_get_name(rdev));
962 		return -EBUSY;
963 	}
964 
965 	node = kzalloc(sizeof(struct regulator_map), GFP_KERNEL);
966 	if (node == NULL)
967 		return -ENOMEM;
968 
969 	node->regulator = rdev;
970 	node->supply = supply;
971 
972 	if (has_dev) {
973 		node->dev_name = kstrdup(consumer_dev_name, GFP_KERNEL);
974 		if (node->dev_name == NULL) {
975 			kfree(node);
976 			return -ENOMEM;
977 		}
978 	}
979 
980 	list_add(&node->list, &regulator_map_list);
981 	return 0;
982 }
983 
984 static void unset_regulator_supplies(struct regulator_dev *rdev)
985 {
986 	struct regulator_map *node, *n;
987 
988 	list_for_each_entry_safe(node, n, &regulator_map_list, list) {
989 		if (rdev == node->regulator) {
990 			list_del(&node->list);
991 			kfree(node->dev_name);
992 			kfree(node);
993 		}
994 	}
995 }
996 
997 #define REG_STR_SIZE	32
998 
999 static struct regulator *create_regulator(struct regulator_dev *rdev,
1000 					  struct device *dev,
1001 					  const char *supply_name)
1002 {
1003 	struct regulator *regulator;
1004 	char buf[REG_STR_SIZE];
1005 	int err, size;
1006 
1007 	regulator = kzalloc(sizeof(*regulator), GFP_KERNEL);
1008 	if (regulator == NULL)
1009 		return NULL;
1010 
1011 	mutex_lock(&rdev->mutex);
1012 	regulator->rdev = rdev;
1013 	list_add(&regulator->list, &rdev->consumer_list);
1014 
1015 	if (dev) {
1016 		/* create a 'requested_microamps_name' sysfs entry */
1017 		size = scnprintf(buf, REG_STR_SIZE, "microamps_requested_%s",
1018 			supply_name);
1019 		if (size >= REG_STR_SIZE)
1020 			goto overflow_err;
1021 
1022 		regulator->dev = dev;
1023 		sysfs_attr_init(&regulator->dev_attr.attr);
1024 		regulator->dev_attr.attr.name = kstrdup(buf, GFP_KERNEL);
1025 		if (regulator->dev_attr.attr.name == NULL)
1026 			goto attr_name_err;
1027 
1028 		regulator->dev_attr.attr.owner = THIS_MODULE;
1029 		regulator->dev_attr.attr.mode = 0444;
1030 		regulator->dev_attr.show = device_requested_uA_show;
1031 		err = device_create_file(dev, &regulator->dev_attr);
1032 		if (err < 0) {
1033 			printk(KERN_WARNING "%s: could not add regulator_dev"
1034 				" load sysfs\n", __func__);
1035 			goto attr_name_err;
1036 		}
1037 
1038 		/* also add a link to the device sysfs entry */
1039 		size = scnprintf(buf, REG_STR_SIZE, "%s-%s",
1040 				 dev->kobj.name, supply_name);
1041 		if (size >= REG_STR_SIZE)
1042 			goto attr_err;
1043 
1044 		regulator->supply_name = kstrdup(buf, GFP_KERNEL);
1045 		if (regulator->supply_name == NULL)
1046 			goto attr_err;
1047 
1048 		err = sysfs_create_link(&rdev->dev.kobj, &dev->kobj,
1049 					buf);
1050 		if (err) {
1051 			printk(KERN_WARNING
1052 			       "%s: could not add device link %s err %d\n",
1053 			       __func__, dev->kobj.name, err);
1054 			device_remove_file(dev, &regulator->dev_attr);
1055 			goto link_name_err;
1056 		}
1057 	}
1058 	mutex_unlock(&rdev->mutex);
1059 	return regulator;
1060 link_name_err:
1061 	kfree(regulator->supply_name);
1062 attr_err:
1063 	device_remove_file(regulator->dev, &regulator->dev_attr);
1064 attr_name_err:
1065 	kfree(regulator->dev_attr.attr.name);
1066 overflow_err:
1067 	list_del(&regulator->list);
1068 	kfree(regulator);
1069 	mutex_unlock(&rdev->mutex);
1070 	return NULL;
1071 }
1072 
1073 static int _regulator_get_enable_time(struct regulator_dev *rdev)
1074 {
1075 	if (!rdev->desc->ops->enable_time)
1076 		return 0;
1077 	return rdev->desc->ops->enable_time(rdev);
1078 }
1079 
1080 /* Internal regulator request function */
1081 static struct regulator *_regulator_get(struct device *dev, const char *id,
1082 					int exclusive)
1083 {
1084 	struct regulator_dev *rdev;
1085 	struct regulator_map *map;
1086 	struct regulator *regulator = ERR_PTR(-ENODEV);
1087 	const char *devname = NULL;
1088 	int ret;
1089 
1090 	if (id == NULL) {
1091 		printk(KERN_ERR "regulator: get() with no identifier\n");
1092 		return regulator;
1093 	}
1094 
1095 	if (dev)
1096 		devname = dev_name(dev);
1097 
1098 	mutex_lock(&regulator_list_mutex);
1099 
1100 	list_for_each_entry(map, &regulator_map_list, list) {
1101 		/* If the mapping has a device set up it must match */
1102 		if (map->dev_name &&
1103 		    (!devname || strcmp(map->dev_name, devname)))
1104 			continue;
1105 
1106 		if (strcmp(map->supply, id) == 0) {
1107 			rdev = map->regulator;
1108 			goto found;
1109 		}
1110 	}
1111 
1112 #ifdef CONFIG_REGULATOR_DUMMY
1113 	if (!devname)
1114 		devname = "deviceless";
1115 
1116 	/* If the board didn't flag that it was fully constrained then
1117 	 * substitute in a dummy regulator so consumers can continue.
1118 	 */
1119 	if (!has_full_constraints) {
1120 		pr_warning("%s supply %s not found, using dummy regulator\n",
1121 			   devname, id);
1122 		rdev = dummy_regulator_rdev;
1123 		goto found;
1124 	}
1125 #endif
1126 
1127 	mutex_unlock(&regulator_list_mutex);
1128 	return regulator;
1129 
1130 found:
1131 	if (rdev->exclusive) {
1132 		regulator = ERR_PTR(-EPERM);
1133 		goto out;
1134 	}
1135 
1136 	if (exclusive && rdev->open_count) {
1137 		regulator = ERR_PTR(-EBUSY);
1138 		goto out;
1139 	}
1140 
1141 	if (!try_module_get(rdev->owner))
1142 		goto out;
1143 
1144 	regulator = create_regulator(rdev, dev, id);
1145 	if (regulator == NULL) {
1146 		regulator = ERR_PTR(-ENOMEM);
1147 		module_put(rdev->owner);
1148 	}
1149 
1150 	rdev->open_count++;
1151 	if (exclusive) {
1152 		rdev->exclusive = 1;
1153 
1154 		ret = _regulator_is_enabled(rdev);
1155 		if (ret > 0)
1156 			rdev->use_count = 1;
1157 		else
1158 			rdev->use_count = 0;
1159 	}
1160 
1161 out:
1162 	mutex_unlock(&regulator_list_mutex);
1163 
1164 	return regulator;
1165 }
1166 
1167 /**
1168  * regulator_get - lookup and obtain a reference to a regulator.
1169  * @dev: device for regulator "consumer"
1170  * @id: Supply name or regulator ID.
1171  *
1172  * Returns a struct regulator corresponding to the regulator producer,
1173  * or IS_ERR() condition containing errno.
1174  *
1175  * Use of supply names configured via regulator_set_device_supply() is
1176  * strongly encouraged.  It is recommended that the supply name used
1177  * should match the name used for the supply and/or the relevant
1178  * device pins in the datasheet.
1179  */
1180 struct regulator *regulator_get(struct device *dev, const char *id)
1181 {
1182 	return _regulator_get(dev, id, 0);
1183 }
1184 EXPORT_SYMBOL_GPL(regulator_get);
1185 
1186 /**
1187  * regulator_get_exclusive - obtain exclusive access to a regulator.
1188  * @dev: device for regulator "consumer"
1189  * @id: Supply name or regulator ID.
1190  *
1191  * Returns a struct regulator corresponding to the regulator producer,
1192  * or IS_ERR() condition containing errno.  Other consumers will be
1193  * unable to obtain this reference is held and the use count for the
1194  * regulator will be initialised to reflect the current state of the
1195  * regulator.
1196  *
1197  * This is intended for use by consumers which cannot tolerate shared
1198  * use of the regulator such as those which need to force the
1199  * regulator off for correct operation of the hardware they are
1200  * controlling.
1201  *
1202  * Use of supply names configured via regulator_set_device_supply() is
1203  * strongly encouraged.  It is recommended that the supply name used
1204  * should match the name used for the supply and/or the relevant
1205  * device pins in the datasheet.
1206  */
1207 struct regulator *regulator_get_exclusive(struct device *dev, const char *id)
1208 {
1209 	return _regulator_get(dev, id, 1);
1210 }
1211 EXPORT_SYMBOL_GPL(regulator_get_exclusive);
1212 
1213 /**
1214  * regulator_put - "free" the regulator source
1215  * @regulator: regulator source
1216  *
1217  * Note: drivers must ensure that all regulator_enable calls made on this
1218  * regulator source are balanced by regulator_disable calls prior to calling
1219  * this function.
1220  */
1221 void regulator_put(struct regulator *regulator)
1222 {
1223 	struct regulator_dev *rdev;
1224 
1225 	if (regulator == NULL || IS_ERR(regulator))
1226 		return;
1227 
1228 	mutex_lock(&regulator_list_mutex);
1229 	rdev = regulator->rdev;
1230 
1231 	/* remove any sysfs entries */
1232 	if (regulator->dev) {
1233 		sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
1234 		kfree(regulator->supply_name);
1235 		device_remove_file(regulator->dev, &regulator->dev_attr);
1236 		kfree(regulator->dev_attr.attr.name);
1237 	}
1238 	list_del(&regulator->list);
1239 	kfree(regulator);
1240 
1241 	rdev->open_count--;
1242 	rdev->exclusive = 0;
1243 
1244 	module_put(rdev->owner);
1245 	mutex_unlock(&regulator_list_mutex);
1246 }
1247 EXPORT_SYMBOL_GPL(regulator_put);
1248 
1249 static int _regulator_can_change_status(struct regulator_dev *rdev)
1250 {
1251 	if (!rdev->constraints)
1252 		return 0;
1253 
1254 	if (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_STATUS)
1255 		return 1;
1256 	else
1257 		return 0;
1258 }
1259 
1260 /* locks held by regulator_enable() */
1261 static int _regulator_enable(struct regulator_dev *rdev)
1262 {
1263 	int ret, delay;
1264 
1265 	/* do we need to enable the supply regulator first */
1266 	if (rdev->supply) {
1267 		ret = _regulator_enable(rdev->supply);
1268 		if (ret < 0) {
1269 			printk(KERN_ERR "%s: failed to enable %s: %d\n",
1270 			       __func__, rdev_get_name(rdev), ret);
1271 			return ret;
1272 		}
1273 	}
1274 
1275 	/* check voltage and requested load before enabling */
1276 	if (rdev->constraints &&
1277 	    (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS))
1278 		drms_uA_update(rdev);
1279 
1280 	if (rdev->use_count == 0) {
1281 		/* The regulator may on if it's not switchable or left on */
1282 		ret = _regulator_is_enabled(rdev);
1283 		if (ret == -EINVAL || ret == 0) {
1284 			if (!_regulator_can_change_status(rdev))
1285 				return -EPERM;
1286 
1287 			if (!rdev->desc->ops->enable)
1288 				return -EINVAL;
1289 
1290 			/* Query before enabling in case configuration
1291 			 * dependant.  */
1292 			ret = _regulator_get_enable_time(rdev);
1293 			if (ret >= 0) {
1294 				delay = ret;
1295 			} else {
1296 				printk(KERN_WARNING
1297 					"%s: enable_time() failed for %s: %d\n",
1298 					__func__, rdev_get_name(rdev),
1299 					ret);
1300 				delay = 0;
1301 			}
1302 
1303 			/* Allow the regulator to ramp; it would be useful
1304 			 * to extend this for bulk operations so that the
1305 			 * regulators can ramp together.  */
1306 			ret = rdev->desc->ops->enable(rdev);
1307 			if (ret < 0)
1308 				return ret;
1309 
1310 			if (delay >= 1000)
1311 				mdelay(delay / 1000);
1312 			else if (delay)
1313 				udelay(delay);
1314 
1315 		} else if (ret < 0) {
1316 			printk(KERN_ERR "%s: is_enabled() failed for %s: %d\n",
1317 			       __func__, rdev_get_name(rdev), ret);
1318 			return ret;
1319 		}
1320 		/* Fallthrough on positive return values - already enabled */
1321 	}
1322 
1323 	rdev->use_count++;
1324 
1325 	return 0;
1326 }
1327 
1328 /**
1329  * regulator_enable - enable regulator output
1330  * @regulator: regulator source
1331  *
1332  * Request that the regulator be enabled with the regulator output at
1333  * the predefined voltage or current value.  Calls to regulator_enable()
1334  * must be balanced with calls to regulator_disable().
1335  *
1336  * NOTE: the output value can be set by other drivers, boot loader or may be
1337  * hardwired in the regulator.
1338  */
1339 int regulator_enable(struct regulator *regulator)
1340 {
1341 	struct regulator_dev *rdev = regulator->rdev;
1342 	int ret = 0;
1343 
1344 	mutex_lock(&rdev->mutex);
1345 	ret = _regulator_enable(rdev);
1346 	mutex_unlock(&rdev->mutex);
1347 	return ret;
1348 }
1349 EXPORT_SYMBOL_GPL(regulator_enable);
1350 
1351 /* locks held by regulator_disable() */
1352 static int _regulator_disable(struct regulator_dev *rdev)
1353 {
1354 	int ret = 0;
1355 
1356 	if (WARN(rdev->use_count <= 0,
1357 			"unbalanced disables for %s\n",
1358 			rdev_get_name(rdev)))
1359 		return -EIO;
1360 
1361 	/* are we the last user and permitted to disable ? */
1362 	if (rdev->use_count == 1 &&
1363 	    (rdev->constraints && !rdev->constraints->always_on)) {
1364 
1365 		/* we are last user */
1366 		if (_regulator_can_change_status(rdev) &&
1367 		    rdev->desc->ops->disable) {
1368 			ret = rdev->desc->ops->disable(rdev);
1369 			if (ret < 0) {
1370 				printk(KERN_ERR "%s: failed to disable %s\n",
1371 				       __func__, rdev_get_name(rdev));
1372 				return ret;
1373 			}
1374 
1375 			_notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE,
1376 					     NULL);
1377 		}
1378 
1379 		/* decrease our supplies ref count and disable if required */
1380 		if (rdev->supply)
1381 			_regulator_disable(rdev->supply);
1382 
1383 		rdev->use_count = 0;
1384 	} else if (rdev->use_count > 1) {
1385 
1386 		if (rdev->constraints &&
1387 			(rdev->constraints->valid_ops_mask &
1388 			REGULATOR_CHANGE_DRMS))
1389 			drms_uA_update(rdev);
1390 
1391 		rdev->use_count--;
1392 	}
1393 	return ret;
1394 }
1395 
1396 /**
1397  * regulator_disable - disable regulator output
1398  * @regulator: regulator source
1399  *
1400  * Disable the regulator output voltage or current.  Calls to
1401  * regulator_enable() must be balanced with calls to
1402  * regulator_disable().
1403  *
1404  * NOTE: this will only disable the regulator output if no other consumer
1405  * devices have it enabled, the regulator device supports disabling and
1406  * machine constraints permit this operation.
1407  */
1408 int regulator_disable(struct regulator *regulator)
1409 {
1410 	struct regulator_dev *rdev = regulator->rdev;
1411 	int ret = 0;
1412 
1413 	mutex_lock(&rdev->mutex);
1414 	ret = _regulator_disable(rdev);
1415 	mutex_unlock(&rdev->mutex);
1416 	return ret;
1417 }
1418 EXPORT_SYMBOL_GPL(regulator_disable);
1419 
1420 /* locks held by regulator_force_disable() */
1421 static int _regulator_force_disable(struct regulator_dev *rdev)
1422 {
1423 	int ret = 0;
1424 
1425 	/* force disable */
1426 	if (rdev->desc->ops->disable) {
1427 		/* ah well, who wants to live forever... */
1428 		ret = rdev->desc->ops->disable(rdev);
1429 		if (ret < 0) {
1430 			printk(KERN_ERR "%s: failed to force disable %s\n",
1431 			       __func__, rdev_get_name(rdev));
1432 			return ret;
1433 		}
1434 		/* notify other consumers that power has been forced off */
1435 		_notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE |
1436 			REGULATOR_EVENT_DISABLE, NULL);
1437 	}
1438 
1439 	/* decrease our supplies ref count and disable if required */
1440 	if (rdev->supply)
1441 		_regulator_disable(rdev->supply);
1442 
1443 	rdev->use_count = 0;
1444 	return ret;
1445 }
1446 
1447 /**
1448  * regulator_force_disable - force disable regulator output
1449  * @regulator: regulator source
1450  *
1451  * Forcibly disable the regulator output voltage or current.
1452  * NOTE: this *will* disable the regulator output even if other consumer
1453  * devices have it enabled. This should be used for situations when device
1454  * damage will likely occur if the regulator is not disabled (e.g. over temp).
1455  */
1456 int regulator_force_disable(struct regulator *regulator)
1457 {
1458 	int ret;
1459 
1460 	mutex_lock(&regulator->rdev->mutex);
1461 	regulator->uA_load = 0;
1462 	ret = _regulator_force_disable(regulator->rdev);
1463 	mutex_unlock(&regulator->rdev->mutex);
1464 	return ret;
1465 }
1466 EXPORT_SYMBOL_GPL(regulator_force_disable);
1467 
1468 static int _regulator_is_enabled(struct regulator_dev *rdev)
1469 {
1470 	/* If we don't know then assume that the regulator is always on */
1471 	if (!rdev->desc->ops->is_enabled)
1472 		return 1;
1473 
1474 	return rdev->desc->ops->is_enabled(rdev);
1475 }
1476 
1477 /**
1478  * regulator_is_enabled - is the regulator output enabled
1479  * @regulator: regulator source
1480  *
1481  * Returns positive if the regulator driver backing the source/client
1482  * has requested that the device be enabled, zero if it hasn't, else a
1483  * negative errno code.
1484  *
1485  * Note that the device backing this regulator handle can have multiple
1486  * users, so it might be enabled even if regulator_enable() was never
1487  * called for this particular source.
1488  */
1489 int regulator_is_enabled(struct regulator *regulator)
1490 {
1491 	int ret;
1492 
1493 	mutex_lock(&regulator->rdev->mutex);
1494 	ret = _regulator_is_enabled(regulator->rdev);
1495 	mutex_unlock(&regulator->rdev->mutex);
1496 
1497 	return ret;
1498 }
1499 EXPORT_SYMBOL_GPL(regulator_is_enabled);
1500 
1501 /**
1502  * regulator_count_voltages - count regulator_list_voltage() selectors
1503  * @regulator: regulator source
1504  *
1505  * Returns number of selectors, or negative errno.  Selectors are
1506  * numbered starting at zero, and typically correspond to bitfields
1507  * in hardware registers.
1508  */
1509 int regulator_count_voltages(struct regulator *regulator)
1510 {
1511 	struct regulator_dev	*rdev = regulator->rdev;
1512 
1513 	return rdev->desc->n_voltages ? : -EINVAL;
1514 }
1515 EXPORT_SYMBOL_GPL(regulator_count_voltages);
1516 
1517 /**
1518  * regulator_list_voltage - enumerate supported voltages
1519  * @regulator: regulator source
1520  * @selector: identify voltage to list
1521  * Context: can sleep
1522  *
1523  * Returns a voltage that can be passed to @regulator_set_voltage(),
1524  * zero if this selector code can't be used on this system, or a
1525  * negative errno.
1526  */
1527 int regulator_list_voltage(struct regulator *regulator, unsigned selector)
1528 {
1529 	struct regulator_dev	*rdev = regulator->rdev;
1530 	struct regulator_ops	*ops = rdev->desc->ops;
1531 	int			ret;
1532 
1533 	if (!ops->list_voltage || selector >= rdev->desc->n_voltages)
1534 		return -EINVAL;
1535 
1536 	mutex_lock(&rdev->mutex);
1537 	ret = ops->list_voltage(rdev, selector);
1538 	mutex_unlock(&rdev->mutex);
1539 
1540 	if (ret > 0) {
1541 		if (ret < rdev->constraints->min_uV)
1542 			ret = 0;
1543 		else if (ret > rdev->constraints->max_uV)
1544 			ret = 0;
1545 	}
1546 
1547 	return ret;
1548 }
1549 EXPORT_SYMBOL_GPL(regulator_list_voltage);
1550 
1551 /**
1552  * regulator_is_supported_voltage - check if a voltage range can be supported
1553  *
1554  * @regulator: Regulator to check.
1555  * @min_uV: Minimum required voltage in uV.
1556  * @max_uV: Maximum required voltage in uV.
1557  *
1558  * Returns a boolean or a negative error code.
1559  */
1560 int regulator_is_supported_voltage(struct regulator *regulator,
1561 				   int min_uV, int max_uV)
1562 {
1563 	int i, voltages, ret;
1564 
1565 	ret = regulator_count_voltages(regulator);
1566 	if (ret < 0)
1567 		return ret;
1568 	voltages = ret;
1569 
1570 	for (i = 0; i < voltages; i++) {
1571 		ret = regulator_list_voltage(regulator, i);
1572 
1573 		if (ret >= min_uV && ret <= max_uV)
1574 			return 1;
1575 	}
1576 
1577 	return 0;
1578 }
1579 
1580 /**
1581  * regulator_set_voltage - set regulator output voltage
1582  * @regulator: regulator source
1583  * @min_uV: Minimum required voltage in uV
1584  * @max_uV: Maximum acceptable voltage in uV
1585  *
1586  * Sets a voltage regulator to the desired output voltage. This can be set
1587  * during any regulator state. IOW, regulator can be disabled or enabled.
1588  *
1589  * If the regulator is enabled then the voltage will change to the new value
1590  * immediately otherwise if the regulator is disabled the regulator will
1591  * output at the new voltage when enabled.
1592  *
1593  * NOTE: If the regulator is shared between several devices then the lowest
1594  * request voltage that meets the system constraints will be used.
1595  * Regulator system constraints must be set for this regulator before
1596  * calling this function otherwise this call will fail.
1597  */
1598 int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
1599 {
1600 	struct regulator_dev *rdev = regulator->rdev;
1601 	int ret;
1602 
1603 	mutex_lock(&rdev->mutex);
1604 
1605 	/* sanity check */
1606 	if (!rdev->desc->ops->set_voltage) {
1607 		ret = -EINVAL;
1608 		goto out;
1609 	}
1610 
1611 	/* constraints check */
1612 	ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
1613 	if (ret < 0)
1614 		goto out;
1615 	regulator->min_uV = min_uV;
1616 	regulator->max_uV = max_uV;
1617 	ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV);
1618 
1619 out:
1620 	_notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE, NULL);
1621 	mutex_unlock(&rdev->mutex);
1622 	return ret;
1623 }
1624 EXPORT_SYMBOL_GPL(regulator_set_voltage);
1625 
1626 static int _regulator_get_voltage(struct regulator_dev *rdev)
1627 {
1628 	/* sanity check */
1629 	if (rdev->desc->ops->get_voltage)
1630 		return rdev->desc->ops->get_voltage(rdev);
1631 	else
1632 		return -EINVAL;
1633 }
1634 
1635 /**
1636  * regulator_get_voltage - get regulator output voltage
1637  * @regulator: regulator source
1638  *
1639  * This returns the current regulator voltage in uV.
1640  *
1641  * NOTE: If the regulator is disabled it will return the voltage value. This
1642  * function should not be used to determine regulator state.
1643  */
1644 int regulator_get_voltage(struct regulator *regulator)
1645 {
1646 	int ret;
1647 
1648 	mutex_lock(&regulator->rdev->mutex);
1649 
1650 	ret = _regulator_get_voltage(regulator->rdev);
1651 
1652 	mutex_unlock(&regulator->rdev->mutex);
1653 
1654 	return ret;
1655 }
1656 EXPORT_SYMBOL_GPL(regulator_get_voltage);
1657 
1658 /**
1659  * regulator_set_current_limit - set regulator output current limit
1660  * @regulator: regulator source
1661  * @min_uA: Minimuum supported current in uA
1662  * @max_uA: Maximum supported current in uA
1663  *
1664  * Sets current sink to the desired output current. This can be set during
1665  * any regulator state. IOW, regulator can be disabled or enabled.
1666  *
1667  * If the regulator is enabled then the current will change to the new value
1668  * immediately otherwise if the regulator is disabled the regulator will
1669  * output at the new current when enabled.
1670  *
1671  * NOTE: Regulator system constraints must be set for this regulator before
1672  * calling this function otherwise this call will fail.
1673  */
1674 int regulator_set_current_limit(struct regulator *regulator,
1675 			       int min_uA, int max_uA)
1676 {
1677 	struct regulator_dev *rdev = regulator->rdev;
1678 	int ret;
1679 
1680 	mutex_lock(&rdev->mutex);
1681 
1682 	/* sanity check */
1683 	if (!rdev->desc->ops->set_current_limit) {
1684 		ret = -EINVAL;
1685 		goto out;
1686 	}
1687 
1688 	/* constraints check */
1689 	ret = regulator_check_current_limit(rdev, &min_uA, &max_uA);
1690 	if (ret < 0)
1691 		goto out;
1692 
1693 	ret = rdev->desc->ops->set_current_limit(rdev, min_uA, max_uA);
1694 out:
1695 	mutex_unlock(&rdev->mutex);
1696 	return ret;
1697 }
1698 EXPORT_SYMBOL_GPL(regulator_set_current_limit);
1699 
1700 static int _regulator_get_current_limit(struct regulator_dev *rdev)
1701 {
1702 	int ret;
1703 
1704 	mutex_lock(&rdev->mutex);
1705 
1706 	/* sanity check */
1707 	if (!rdev->desc->ops->get_current_limit) {
1708 		ret = -EINVAL;
1709 		goto out;
1710 	}
1711 
1712 	ret = rdev->desc->ops->get_current_limit(rdev);
1713 out:
1714 	mutex_unlock(&rdev->mutex);
1715 	return ret;
1716 }
1717 
1718 /**
1719  * regulator_get_current_limit - get regulator output current
1720  * @regulator: regulator source
1721  *
1722  * This returns the current supplied by the specified current sink in uA.
1723  *
1724  * NOTE: If the regulator is disabled it will return the current value. This
1725  * function should not be used to determine regulator state.
1726  */
1727 int regulator_get_current_limit(struct regulator *regulator)
1728 {
1729 	return _regulator_get_current_limit(regulator->rdev);
1730 }
1731 EXPORT_SYMBOL_GPL(regulator_get_current_limit);
1732 
1733 /**
1734  * regulator_set_mode - set regulator operating mode
1735  * @regulator: regulator source
1736  * @mode: operating mode - one of the REGULATOR_MODE constants
1737  *
1738  * Set regulator operating mode to increase regulator efficiency or improve
1739  * regulation performance.
1740  *
1741  * NOTE: Regulator system constraints must be set for this regulator before
1742  * calling this function otherwise this call will fail.
1743  */
1744 int regulator_set_mode(struct regulator *regulator, unsigned int mode)
1745 {
1746 	struct regulator_dev *rdev = regulator->rdev;
1747 	int ret;
1748 	int regulator_curr_mode;
1749 
1750 	mutex_lock(&rdev->mutex);
1751 
1752 	/* sanity check */
1753 	if (!rdev->desc->ops->set_mode) {
1754 		ret = -EINVAL;
1755 		goto out;
1756 	}
1757 
1758 	/* return if the same mode is requested */
1759 	if (rdev->desc->ops->get_mode) {
1760 		regulator_curr_mode = rdev->desc->ops->get_mode(rdev);
1761 		if (regulator_curr_mode == mode) {
1762 			ret = 0;
1763 			goto out;
1764 		}
1765 	}
1766 
1767 	/* constraints check */
1768 	ret = regulator_check_mode(rdev, mode);
1769 	if (ret < 0)
1770 		goto out;
1771 
1772 	ret = rdev->desc->ops->set_mode(rdev, mode);
1773 out:
1774 	mutex_unlock(&rdev->mutex);
1775 	return ret;
1776 }
1777 EXPORT_SYMBOL_GPL(regulator_set_mode);
1778 
1779 static unsigned int _regulator_get_mode(struct regulator_dev *rdev)
1780 {
1781 	int ret;
1782 
1783 	mutex_lock(&rdev->mutex);
1784 
1785 	/* sanity check */
1786 	if (!rdev->desc->ops->get_mode) {
1787 		ret = -EINVAL;
1788 		goto out;
1789 	}
1790 
1791 	ret = rdev->desc->ops->get_mode(rdev);
1792 out:
1793 	mutex_unlock(&rdev->mutex);
1794 	return ret;
1795 }
1796 
1797 /**
1798  * regulator_get_mode - get regulator operating mode
1799  * @regulator: regulator source
1800  *
1801  * Get the current regulator operating mode.
1802  */
1803 unsigned int regulator_get_mode(struct regulator *regulator)
1804 {
1805 	return _regulator_get_mode(regulator->rdev);
1806 }
1807 EXPORT_SYMBOL_GPL(regulator_get_mode);
1808 
1809 /**
1810  * regulator_set_optimum_mode - set regulator optimum operating mode
1811  * @regulator: regulator source
1812  * @uA_load: load current
1813  *
1814  * Notifies the regulator core of a new device load. This is then used by
1815  * DRMS (if enabled by constraints) to set the most efficient regulator
1816  * operating mode for the new regulator loading.
1817  *
1818  * Consumer devices notify their supply regulator of the maximum power
1819  * they will require (can be taken from device datasheet in the power
1820  * consumption tables) when they change operational status and hence power
1821  * state. Examples of operational state changes that can affect power
1822  * consumption are :-
1823  *
1824  *    o Device is opened / closed.
1825  *    o Device I/O is about to begin or has just finished.
1826  *    o Device is idling in between work.
1827  *
1828  * This information is also exported via sysfs to userspace.
1829  *
1830  * DRMS will sum the total requested load on the regulator and change
1831  * to the most efficient operating mode if platform constraints allow.
1832  *
1833  * Returns the new regulator mode or error.
1834  */
1835 int regulator_set_optimum_mode(struct regulator *regulator, int uA_load)
1836 {
1837 	struct regulator_dev *rdev = regulator->rdev;
1838 	struct regulator *consumer;
1839 	int ret, output_uV, input_uV, total_uA_load = 0;
1840 	unsigned int mode;
1841 
1842 	mutex_lock(&rdev->mutex);
1843 
1844 	regulator->uA_load = uA_load;
1845 	ret = regulator_check_drms(rdev);
1846 	if (ret < 0)
1847 		goto out;
1848 	ret = -EINVAL;
1849 
1850 	/* sanity check */
1851 	if (!rdev->desc->ops->get_optimum_mode)
1852 		goto out;
1853 
1854 	/* get output voltage */
1855 	output_uV = rdev->desc->ops->get_voltage(rdev);
1856 	if (output_uV <= 0) {
1857 		printk(KERN_ERR "%s: invalid output voltage found for %s\n",
1858 			__func__, rdev_get_name(rdev));
1859 		goto out;
1860 	}
1861 
1862 	/* get input voltage */
1863 	if (rdev->supply && rdev->supply->desc->ops->get_voltage)
1864 		input_uV = rdev->supply->desc->ops->get_voltage(rdev->supply);
1865 	else
1866 		input_uV = rdev->constraints->input_uV;
1867 	if (input_uV <= 0) {
1868 		printk(KERN_ERR "%s: invalid input voltage found for %s\n",
1869 			__func__, rdev_get_name(rdev));
1870 		goto out;
1871 	}
1872 
1873 	/* calc total requested load for this regulator */
1874 	list_for_each_entry(consumer, &rdev->consumer_list, list)
1875 		total_uA_load += consumer->uA_load;
1876 
1877 	mode = rdev->desc->ops->get_optimum_mode(rdev,
1878 						 input_uV, output_uV,
1879 						 total_uA_load);
1880 	ret = regulator_check_mode(rdev, mode);
1881 	if (ret < 0) {
1882 		printk(KERN_ERR "%s: failed to get optimum mode for %s @"
1883 			" %d uA %d -> %d uV\n", __func__, rdev_get_name(rdev),
1884 			total_uA_load, input_uV, output_uV);
1885 		goto out;
1886 	}
1887 
1888 	ret = rdev->desc->ops->set_mode(rdev, mode);
1889 	if (ret < 0) {
1890 		printk(KERN_ERR "%s: failed to set optimum mode %x for %s\n",
1891 			__func__, mode, rdev_get_name(rdev));
1892 		goto out;
1893 	}
1894 	ret = mode;
1895 out:
1896 	mutex_unlock(&rdev->mutex);
1897 	return ret;
1898 }
1899 EXPORT_SYMBOL_GPL(regulator_set_optimum_mode);
1900 
1901 /**
1902  * regulator_register_notifier - register regulator event notifier
1903  * @regulator: regulator source
1904  * @nb: notifier block
1905  *
1906  * Register notifier block to receive regulator events.
1907  */
1908 int regulator_register_notifier(struct regulator *regulator,
1909 			      struct notifier_block *nb)
1910 {
1911 	return blocking_notifier_chain_register(&regulator->rdev->notifier,
1912 						nb);
1913 }
1914 EXPORT_SYMBOL_GPL(regulator_register_notifier);
1915 
1916 /**
1917  * regulator_unregister_notifier - unregister regulator event notifier
1918  * @regulator: regulator source
1919  * @nb: notifier block
1920  *
1921  * Unregister regulator event notifier block.
1922  */
1923 int regulator_unregister_notifier(struct regulator *regulator,
1924 				struct notifier_block *nb)
1925 {
1926 	return blocking_notifier_chain_unregister(&regulator->rdev->notifier,
1927 						  nb);
1928 }
1929 EXPORT_SYMBOL_GPL(regulator_unregister_notifier);
1930 
1931 /* notify regulator consumers and downstream regulator consumers.
1932  * Note mutex must be held by caller.
1933  */
1934 static void _notifier_call_chain(struct regulator_dev *rdev,
1935 				  unsigned long event, void *data)
1936 {
1937 	struct regulator_dev *_rdev;
1938 
1939 	/* call rdev chain first */
1940 	blocking_notifier_call_chain(&rdev->notifier, event, NULL);
1941 
1942 	/* now notify regulator we supply */
1943 	list_for_each_entry(_rdev, &rdev->supply_list, slist) {
1944 		mutex_lock(&_rdev->mutex);
1945 		_notifier_call_chain(_rdev, event, data);
1946 		mutex_unlock(&_rdev->mutex);
1947 	}
1948 }
1949 
1950 /**
1951  * regulator_bulk_get - get multiple regulator consumers
1952  *
1953  * @dev:           Device to supply
1954  * @num_consumers: Number of consumers to register
1955  * @consumers:     Configuration of consumers; clients are stored here.
1956  *
1957  * @return 0 on success, an errno on failure.
1958  *
1959  * This helper function allows drivers to get several regulator
1960  * consumers in one operation.  If any of the regulators cannot be
1961  * acquired then any regulators that were allocated will be freed
1962  * before returning to the caller.
1963  */
1964 int regulator_bulk_get(struct device *dev, int num_consumers,
1965 		       struct regulator_bulk_data *consumers)
1966 {
1967 	int i;
1968 	int ret;
1969 
1970 	for (i = 0; i < num_consumers; i++)
1971 		consumers[i].consumer = NULL;
1972 
1973 	for (i = 0; i < num_consumers; i++) {
1974 		consumers[i].consumer = regulator_get(dev,
1975 						      consumers[i].supply);
1976 		if (IS_ERR(consumers[i].consumer)) {
1977 			ret = PTR_ERR(consumers[i].consumer);
1978 			dev_err(dev, "Failed to get supply '%s': %d\n",
1979 				consumers[i].supply, ret);
1980 			consumers[i].consumer = NULL;
1981 			goto err;
1982 		}
1983 	}
1984 
1985 	return 0;
1986 
1987 err:
1988 	for (i = 0; i < num_consumers && consumers[i].consumer; i++)
1989 		regulator_put(consumers[i].consumer);
1990 
1991 	return ret;
1992 }
1993 EXPORT_SYMBOL_GPL(regulator_bulk_get);
1994 
1995 /**
1996  * regulator_bulk_enable - enable multiple regulator consumers
1997  *
1998  * @num_consumers: Number of consumers
1999  * @consumers:     Consumer data; clients are stored here.
2000  * @return         0 on success, an errno on failure
2001  *
2002  * This convenience API allows consumers to enable multiple regulator
2003  * clients in a single API call.  If any consumers cannot be enabled
2004  * then any others that were enabled will be disabled again prior to
2005  * return.
2006  */
2007 int regulator_bulk_enable(int num_consumers,
2008 			  struct regulator_bulk_data *consumers)
2009 {
2010 	int i;
2011 	int ret;
2012 
2013 	for (i = 0; i < num_consumers; i++) {
2014 		ret = regulator_enable(consumers[i].consumer);
2015 		if (ret != 0)
2016 			goto err;
2017 	}
2018 
2019 	return 0;
2020 
2021 err:
2022 	printk(KERN_ERR "Failed to enable %s: %d\n", consumers[i].supply, ret);
2023 	for (--i; i >= 0; --i)
2024 		regulator_disable(consumers[i].consumer);
2025 
2026 	return ret;
2027 }
2028 EXPORT_SYMBOL_GPL(regulator_bulk_enable);
2029 
2030 /**
2031  * regulator_bulk_disable - disable multiple regulator consumers
2032  *
2033  * @num_consumers: Number of consumers
2034  * @consumers:     Consumer data; clients are stored here.
2035  * @return         0 on success, an errno on failure
2036  *
2037  * This convenience API allows consumers to disable multiple regulator
2038  * clients in a single API call.  If any consumers cannot be enabled
2039  * then any others that were disabled will be disabled again prior to
2040  * return.
2041  */
2042 int regulator_bulk_disable(int num_consumers,
2043 			   struct regulator_bulk_data *consumers)
2044 {
2045 	int i;
2046 	int ret;
2047 
2048 	for (i = 0; i < num_consumers; i++) {
2049 		ret = regulator_disable(consumers[i].consumer);
2050 		if (ret != 0)
2051 			goto err;
2052 	}
2053 
2054 	return 0;
2055 
2056 err:
2057 	printk(KERN_ERR "Failed to disable %s: %d\n", consumers[i].supply,
2058 	       ret);
2059 	for (--i; i >= 0; --i)
2060 		regulator_enable(consumers[i].consumer);
2061 
2062 	return ret;
2063 }
2064 EXPORT_SYMBOL_GPL(regulator_bulk_disable);
2065 
2066 /**
2067  * regulator_bulk_free - free multiple regulator consumers
2068  *
2069  * @num_consumers: Number of consumers
2070  * @consumers:     Consumer data; clients are stored here.
2071  *
2072  * This convenience API allows consumers to free multiple regulator
2073  * clients in a single API call.
2074  */
2075 void regulator_bulk_free(int num_consumers,
2076 			 struct regulator_bulk_data *consumers)
2077 {
2078 	int i;
2079 
2080 	for (i = 0; i < num_consumers; i++) {
2081 		regulator_put(consumers[i].consumer);
2082 		consumers[i].consumer = NULL;
2083 	}
2084 }
2085 EXPORT_SYMBOL_GPL(regulator_bulk_free);
2086 
2087 /**
2088  * regulator_notifier_call_chain - call regulator event notifier
2089  * @rdev: regulator source
2090  * @event: notifier block
2091  * @data: callback-specific data.
2092  *
2093  * Called by regulator drivers to notify clients a regulator event has
2094  * occurred. We also notify regulator clients downstream.
2095  * Note lock must be held by caller.
2096  */
2097 int regulator_notifier_call_chain(struct regulator_dev *rdev,
2098 				  unsigned long event, void *data)
2099 {
2100 	_notifier_call_chain(rdev, event, data);
2101 	return NOTIFY_DONE;
2102 
2103 }
2104 EXPORT_SYMBOL_GPL(regulator_notifier_call_chain);
2105 
2106 /**
2107  * regulator_mode_to_status - convert a regulator mode into a status
2108  *
2109  * @mode: Mode to convert
2110  *
2111  * Convert a regulator mode into a status.
2112  */
2113 int regulator_mode_to_status(unsigned int mode)
2114 {
2115 	switch (mode) {
2116 	case REGULATOR_MODE_FAST:
2117 		return REGULATOR_STATUS_FAST;
2118 	case REGULATOR_MODE_NORMAL:
2119 		return REGULATOR_STATUS_NORMAL;
2120 	case REGULATOR_MODE_IDLE:
2121 		return REGULATOR_STATUS_IDLE;
2122 	case REGULATOR_STATUS_STANDBY:
2123 		return REGULATOR_STATUS_STANDBY;
2124 	default:
2125 		return 0;
2126 	}
2127 }
2128 EXPORT_SYMBOL_GPL(regulator_mode_to_status);
2129 
2130 /*
2131  * To avoid cluttering sysfs (and memory) with useless state, only
2132  * create attributes that can be meaningfully displayed.
2133  */
2134 static int add_regulator_attributes(struct regulator_dev *rdev)
2135 {
2136 	struct device		*dev = &rdev->dev;
2137 	struct regulator_ops	*ops = rdev->desc->ops;
2138 	int			status = 0;
2139 
2140 	/* some attributes need specific methods to be displayed */
2141 	if (ops->get_voltage) {
2142 		status = device_create_file(dev, &dev_attr_microvolts);
2143 		if (status < 0)
2144 			return status;
2145 	}
2146 	if (ops->get_current_limit) {
2147 		status = device_create_file(dev, &dev_attr_microamps);
2148 		if (status < 0)
2149 			return status;
2150 	}
2151 	if (ops->get_mode) {
2152 		status = device_create_file(dev, &dev_attr_opmode);
2153 		if (status < 0)
2154 			return status;
2155 	}
2156 	if (ops->is_enabled) {
2157 		status = device_create_file(dev, &dev_attr_state);
2158 		if (status < 0)
2159 			return status;
2160 	}
2161 	if (ops->get_status) {
2162 		status = device_create_file(dev, &dev_attr_status);
2163 		if (status < 0)
2164 			return status;
2165 	}
2166 
2167 	/* some attributes are type-specific */
2168 	if (rdev->desc->type == REGULATOR_CURRENT) {
2169 		status = device_create_file(dev, &dev_attr_requested_microamps);
2170 		if (status < 0)
2171 			return status;
2172 	}
2173 
2174 	/* all the other attributes exist to support constraints;
2175 	 * don't show them if there are no constraints, or if the
2176 	 * relevant supporting methods are missing.
2177 	 */
2178 	if (!rdev->constraints)
2179 		return status;
2180 
2181 	/* constraints need specific supporting methods */
2182 	if (ops->set_voltage) {
2183 		status = device_create_file(dev, &dev_attr_min_microvolts);
2184 		if (status < 0)
2185 			return status;
2186 		status = device_create_file(dev, &dev_attr_max_microvolts);
2187 		if (status < 0)
2188 			return status;
2189 	}
2190 	if (ops->set_current_limit) {
2191 		status = device_create_file(dev, &dev_attr_min_microamps);
2192 		if (status < 0)
2193 			return status;
2194 		status = device_create_file(dev, &dev_attr_max_microamps);
2195 		if (status < 0)
2196 			return status;
2197 	}
2198 
2199 	/* suspend mode constraints need multiple supporting methods */
2200 	if (!(ops->set_suspend_enable && ops->set_suspend_disable))
2201 		return status;
2202 
2203 	status = device_create_file(dev, &dev_attr_suspend_standby_state);
2204 	if (status < 0)
2205 		return status;
2206 	status = device_create_file(dev, &dev_attr_suspend_mem_state);
2207 	if (status < 0)
2208 		return status;
2209 	status = device_create_file(dev, &dev_attr_suspend_disk_state);
2210 	if (status < 0)
2211 		return status;
2212 
2213 	if (ops->set_suspend_voltage) {
2214 		status = device_create_file(dev,
2215 				&dev_attr_suspend_standby_microvolts);
2216 		if (status < 0)
2217 			return status;
2218 		status = device_create_file(dev,
2219 				&dev_attr_suspend_mem_microvolts);
2220 		if (status < 0)
2221 			return status;
2222 		status = device_create_file(dev,
2223 				&dev_attr_suspend_disk_microvolts);
2224 		if (status < 0)
2225 			return status;
2226 	}
2227 
2228 	if (ops->set_suspend_mode) {
2229 		status = device_create_file(dev,
2230 				&dev_attr_suspend_standby_mode);
2231 		if (status < 0)
2232 			return status;
2233 		status = device_create_file(dev,
2234 				&dev_attr_suspend_mem_mode);
2235 		if (status < 0)
2236 			return status;
2237 		status = device_create_file(dev,
2238 				&dev_attr_suspend_disk_mode);
2239 		if (status < 0)
2240 			return status;
2241 	}
2242 
2243 	return status;
2244 }
2245 
2246 /**
2247  * regulator_register - register regulator
2248  * @regulator_desc: regulator to register
2249  * @dev: struct device for the regulator
2250  * @init_data: platform provided init data, passed through by driver
2251  * @driver_data: private regulator data
2252  *
2253  * Called by regulator drivers to register a regulator.
2254  * Returns 0 on success.
2255  */
2256 struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
2257 	struct device *dev, struct regulator_init_data *init_data,
2258 	void *driver_data)
2259 {
2260 	static atomic_t regulator_no = ATOMIC_INIT(0);
2261 	struct regulator_dev *rdev;
2262 	int ret, i;
2263 
2264 	if (regulator_desc == NULL)
2265 		return ERR_PTR(-EINVAL);
2266 
2267 	if (regulator_desc->name == NULL || regulator_desc->ops == NULL)
2268 		return ERR_PTR(-EINVAL);
2269 
2270 	if (regulator_desc->type != REGULATOR_VOLTAGE &&
2271 	    regulator_desc->type != REGULATOR_CURRENT)
2272 		return ERR_PTR(-EINVAL);
2273 
2274 	if (!init_data)
2275 		return ERR_PTR(-EINVAL);
2276 
2277 	rdev = kzalloc(sizeof(struct regulator_dev), GFP_KERNEL);
2278 	if (rdev == NULL)
2279 		return ERR_PTR(-ENOMEM);
2280 
2281 	mutex_lock(&regulator_list_mutex);
2282 
2283 	mutex_init(&rdev->mutex);
2284 	rdev->reg_data = driver_data;
2285 	rdev->owner = regulator_desc->owner;
2286 	rdev->desc = regulator_desc;
2287 	INIT_LIST_HEAD(&rdev->consumer_list);
2288 	INIT_LIST_HEAD(&rdev->supply_list);
2289 	INIT_LIST_HEAD(&rdev->list);
2290 	INIT_LIST_HEAD(&rdev->slist);
2291 	BLOCKING_INIT_NOTIFIER_HEAD(&rdev->notifier);
2292 
2293 	/* preform any regulator specific init */
2294 	if (init_data->regulator_init) {
2295 		ret = init_data->regulator_init(rdev->reg_data);
2296 		if (ret < 0)
2297 			goto clean;
2298 	}
2299 
2300 	/* register with sysfs */
2301 	rdev->dev.class = &regulator_class;
2302 	rdev->dev.parent = dev;
2303 	dev_set_name(&rdev->dev, "regulator.%d",
2304 		     atomic_inc_return(&regulator_no) - 1);
2305 	ret = device_register(&rdev->dev);
2306 	if (ret != 0)
2307 		goto clean;
2308 
2309 	dev_set_drvdata(&rdev->dev, rdev);
2310 
2311 	/* set regulator constraints */
2312 	ret = set_machine_constraints(rdev, &init_data->constraints);
2313 	if (ret < 0)
2314 		goto scrub;
2315 
2316 	/* add attributes supported by this regulator */
2317 	ret = add_regulator_attributes(rdev);
2318 	if (ret < 0)
2319 		goto scrub;
2320 
2321 	/* set supply regulator if it exists */
2322 	if (init_data->supply_regulator && init_data->supply_regulator_dev) {
2323 		dev_err(dev,
2324 			"Supply regulator specified by both name and dev\n");
2325 		goto scrub;
2326 	}
2327 
2328 	if (init_data->supply_regulator) {
2329 		struct regulator_dev *r;
2330 		int found = 0;
2331 
2332 		list_for_each_entry(r, &regulator_list, list) {
2333 			if (strcmp(rdev_get_name(r),
2334 				   init_data->supply_regulator) == 0) {
2335 				found = 1;
2336 				break;
2337 			}
2338 		}
2339 
2340 		if (!found) {
2341 			dev_err(dev, "Failed to find supply %s\n",
2342 				init_data->supply_regulator);
2343 			goto scrub;
2344 		}
2345 
2346 		ret = set_supply(rdev, r);
2347 		if (ret < 0)
2348 			goto scrub;
2349 	}
2350 
2351 	if (init_data->supply_regulator_dev) {
2352 		dev_warn(dev, "Uses supply_regulator_dev instead of regulator_supply\n");
2353 		ret = set_supply(rdev,
2354 			dev_get_drvdata(init_data->supply_regulator_dev));
2355 		if (ret < 0)
2356 			goto scrub;
2357 	}
2358 
2359 	/* add consumers devices */
2360 	for (i = 0; i < init_data->num_consumer_supplies; i++) {
2361 		ret = set_consumer_device_supply(rdev,
2362 			init_data->consumer_supplies[i].dev,
2363 			init_data->consumer_supplies[i].dev_name,
2364 			init_data->consumer_supplies[i].supply);
2365 		if (ret < 0)
2366 			goto unset_supplies;
2367 	}
2368 
2369 	list_add(&rdev->list, &regulator_list);
2370 out:
2371 	mutex_unlock(&regulator_list_mutex);
2372 	return rdev;
2373 
2374 unset_supplies:
2375 	unset_regulator_supplies(rdev);
2376 
2377 scrub:
2378 	device_unregister(&rdev->dev);
2379 	/* device core frees rdev */
2380 	rdev = ERR_PTR(ret);
2381 	goto out;
2382 
2383 clean:
2384 	kfree(rdev);
2385 	rdev = ERR_PTR(ret);
2386 	goto out;
2387 }
2388 EXPORT_SYMBOL_GPL(regulator_register);
2389 
2390 /**
2391  * regulator_unregister - unregister regulator
2392  * @rdev: regulator to unregister
2393  *
2394  * Called by regulator drivers to unregister a regulator.
2395  */
2396 void regulator_unregister(struct regulator_dev *rdev)
2397 {
2398 	if (rdev == NULL)
2399 		return;
2400 
2401 	mutex_lock(&regulator_list_mutex);
2402 	WARN_ON(rdev->open_count);
2403 	unset_regulator_supplies(rdev);
2404 	list_del(&rdev->list);
2405 	if (rdev->supply)
2406 		sysfs_remove_link(&rdev->dev.kobj, "supply");
2407 	device_unregister(&rdev->dev);
2408 	mutex_unlock(&regulator_list_mutex);
2409 }
2410 EXPORT_SYMBOL_GPL(regulator_unregister);
2411 
2412 /**
2413  * regulator_suspend_prepare - prepare regulators for system wide suspend
2414  * @state: system suspend state
2415  *
2416  * Configure each regulator with it's suspend operating parameters for state.
2417  * This will usually be called by machine suspend code prior to supending.
2418  */
2419 int regulator_suspend_prepare(suspend_state_t state)
2420 {
2421 	struct regulator_dev *rdev;
2422 	int ret = 0;
2423 
2424 	/* ON is handled by regulator active state */
2425 	if (state == PM_SUSPEND_ON)
2426 		return -EINVAL;
2427 
2428 	mutex_lock(&regulator_list_mutex);
2429 	list_for_each_entry(rdev, &regulator_list, list) {
2430 
2431 		mutex_lock(&rdev->mutex);
2432 		ret = suspend_prepare(rdev, state);
2433 		mutex_unlock(&rdev->mutex);
2434 
2435 		if (ret < 0) {
2436 			printk(KERN_ERR "%s: failed to prepare %s\n",
2437 				__func__, rdev_get_name(rdev));
2438 			goto out;
2439 		}
2440 	}
2441 out:
2442 	mutex_unlock(&regulator_list_mutex);
2443 	return ret;
2444 }
2445 EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
2446 
2447 /**
2448  * regulator_has_full_constraints - the system has fully specified constraints
2449  *
2450  * Calling this function will cause the regulator API to disable all
2451  * regulators which have a zero use count and don't have an always_on
2452  * constraint in a late_initcall.
2453  *
2454  * The intention is that this will become the default behaviour in a
2455  * future kernel release so users are encouraged to use this facility
2456  * now.
2457  */
2458 void regulator_has_full_constraints(void)
2459 {
2460 	has_full_constraints = 1;
2461 }
2462 EXPORT_SYMBOL_GPL(regulator_has_full_constraints);
2463 
2464 /**
2465  * rdev_get_drvdata - get rdev regulator driver data
2466  * @rdev: regulator
2467  *
2468  * Get rdev regulator driver private data. This call can be used in the
2469  * regulator driver context.
2470  */
2471 void *rdev_get_drvdata(struct regulator_dev *rdev)
2472 {
2473 	return rdev->reg_data;
2474 }
2475 EXPORT_SYMBOL_GPL(rdev_get_drvdata);
2476 
2477 /**
2478  * regulator_get_drvdata - get regulator driver data
2479  * @regulator: regulator
2480  *
2481  * Get regulator driver private data. This call can be used in the consumer
2482  * driver context when non API regulator specific functions need to be called.
2483  */
2484 void *regulator_get_drvdata(struct regulator *regulator)
2485 {
2486 	return regulator->rdev->reg_data;
2487 }
2488 EXPORT_SYMBOL_GPL(regulator_get_drvdata);
2489 
2490 /**
2491  * regulator_set_drvdata - set regulator driver data
2492  * @regulator: regulator
2493  * @data: data
2494  */
2495 void regulator_set_drvdata(struct regulator *regulator, void *data)
2496 {
2497 	regulator->rdev->reg_data = data;
2498 }
2499 EXPORT_SYMBOL_GPL(regulator_set_drvdata);
2500 
2501 /**
2502  * regulator_get_id - get regulator ID
2503  * @rdev: regulator
2504  */
2505 int rdev_get_id(struct regulator_dev *rdev)
2506 {
2507 	return rdev->desc->id;
2508 }
2509 EXPORT_SYMBOL_GPL(rdev_get_id);
2510 
2511 struct device *rdev_get_dev(struct regulator_dev *rdev)
2512 {
2513 	return &rdev->dev;
2514 }
2515 EXPORT_SYMBOL_GPL(rdev_get_dev);
2516 
2517 void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data)
2518 {
2519 	return reg_init_data->driver_data;
2520 }
2521 EXPORT_SYMBOL_GPL(regulator_get_init_drvdata);
2522 
2523 static int __init regulator_init(void)
2524 {
2525 	int ret;
2526 
2527 	printk(KERN_INFO "regulator: core version %s\n", REGULATOR_VERSION);
2528 
2529 	ret = class_register(&regulator_class);
2530 
2531 	regulator_dummy_init();
2532 
2533 	return ret;
2534 }
2535 
2536 /* init early to allow our consumers to complete system booting */
2537 core_initcall(regulator_init);
2538 
2539 static int __init regulator_init_complete(void)
2540 {
2541 	struct regulator_dev *rdev;
2542 	struct regulator_ops *ops;
2543 	struct regulation_constraints *c;
2544 	int enabled, ret;
2545 	const char *name;
2546 
2547 	mutex_lock(&regulator_list_mutex);
2548 
2549 	/* If we have a full configuration then disable any regulators
2550 	 * which are not in use or always_on.  This will become the
2551 	 * default behaviour in the future.
2552 	 */
2553 	list_for_each_entry(rdev, &regulator_list, list) {
2554 		ops = rdev->desc->ops;
2555 		c = rdev->constraints;
2556 
2557 		name = rdev_get_name(rdev);
2558 
2559 		if (!ops->disable || (c && c->always_on))
2560 			continue;
2561 
2562 		mutex_lock(&rdev->mutex);
2563 
2564 		if (rdev->use_count)
2565 			goto unlock;
2566 
2567 		/* If we can't read the status assume it's on. */
2568 		if (ops->is_enabled)
2569 			enabled = ops->is_enabled(rdev);
2570 		else
2571 			enabled = 1;
2572 
2573 		if (!enabled)
2574 			goto unlock;
2575 
2576 		if (has_full_constraints) {
2577 			/* We log since this may kill the system if it
2578 			 * goes wrong. */
2579 			printk(KERN_INFO "%s: disabling %s\n",
2580 			       __func__, name);
2581 			ret = ops->disable(rdev);
2582 			if (ret != 0) {
2583 				printk(KERN_ERR
2584 				       "%s: couldn't disable %s: %d\n",
2585 				       __func__, name, ret);
2586 			}
2587 		} else {
2588 			/* The intention is that in future we will
2589 			 * assume that full constraints are provided
2590 			 * so warn even if we aren't going to do
2591 			 * anything here.
2592 			 */
2593 			printk(KERN_WARNING
2594 			       "%s: incomplete constraints, leaving %s on\n",
2595 			       __func__, name);
2596 		}
2597 
2598 unlock:
2599 		mutex_unlock(&rdev->mutex);
2600 	}
2601 
2602 	mutex_unlock(&regulator_list_mutex);
2603 
2604 	return 0;
2605 }
2606 late_initcall(regulator_init_complete);
2607