1/*
2 * helpers.c  --  Voltage/Current Regulator framework helper functions.
3 *
4 * Copyright 2007, 2008 Wolfson Microelectronics PLC.
5 * Copyright 2008 SlimLogic Ltd.
6 *
7 *  This program is free software; you can redistribute  it and/or modify it
8 *  under  the terms of  the GNU General  Public License as published by the
9 *  Free Software Foundation;  either version 2 of the  License, or (at your
10 *  option) any later version.
11 *
12 */
13
14#include <linux/kernel.h>
15#include <linux/err.h>
16#include <linux/delay.h>
17#include <linux/regmap.h>
18#include <linux/regulator/consumer.h>
19#include <linux/regulator/driver.h>
20#include <linux/module.h>
21
22/**
23 * regulator_is_enabled_regmap - standard is_enabled() for regmap users
24 *
25 * @rdev: regulator to operate on
26 *
27 * Regulators that use regmap for their register I/O can set the
28 * enable_reg and enable_mask fields in their descriptor and then use
29 * this as their is_enabled operation, saving some code.
30 */
31int regulator_is_enabled_regmap(struct regulator_dev *rdev)
32{
33	unsigned int val;
34	int ret;
35
36	ret = regmap_read(rdev->regmap, rdev->desc->enable_reg, &val);
37	if (ret != 0)
38		return ret;
39
40	val &= rdev->desc->enable_mask;
41
42	if (rdev->desc->enable_is_inverted) {
43		if (rdev->desc->enable_val)
44			return val != rdev->desc->enable_val;
45		return val == 0;
46	} else {
47		if (rdev->desc->enable_val)
48			return val == rdev->desc->enable_val;
49		return val != 0;
50	}
51}
52EXPORT_SYMBOL_GPL(regulator_is_enabled_regmap);
53
54/**
55 * regulator_enable_regmap - standard enable() for regmap users
56 *
57 * @rdev: regulator to operate on
58 *
59 * Regulators that use regmap for their register I/O can set the
60 * enable_reg and enable_mask fields in their descriptor and then use
61 * this as their enable() operation, saving some code.
62 */
63int regulator_enable_regmap(struct regulator_dev *rdev)
64{
65	unsigned int val;
66
67	if (rdev->desc->enable_is_inverted) {
68		val = rdev->desc->disable_val;
69	} else {
70		val = rdev->desc->enable_val;
71		if (!val)
72			val = rdev->desc->enable_mask;
73	}
74
75	return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
76				  rdev->desc->enable_mask, val);
77}
78EXPORT_SYMBOL_GPL(regulator_enable_regmap);
79
80/**
81 * regulator_disable_regmap - standard disable() for regmap users
82 *
83 * @rdev: regulator to operate on
84 *
85 * Regulators that use regmap for their register I/O can set the
86 * enable_reg and enable_mask fields in their descriptor and then use
87 * this as their disable() operation, saving some code.
88 */
89int regulator_disable_regmap(struct regulator_dev *rdev)
90{
91	unsigned int val;
92
93	if (rdev->desc->enable_is_inverted) {
94		val = rdev->desc->enable_val;
95		if (!val)
96			val = rdev->desc->enable_mask;
97	} else {
98		val = rdev->desc->disable_val;
99	}
100
101	return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
102				  rdev->desc->enable_mask, val);
103}
104EXPORT_SYMBOL_GPL(regulator_disable_regmap);
105
106/**
107 * regulator_get_voltage_sel_regmap - standard get_voltage_sel for regmap users
108 *
109 * @rdev: regulator to operate on
110 *
111 * Regulators that use regmap for their register I/O can set the
112 * vsel_reg and vsel_mask fields in their descriptor and then use this
113 * as their get_voltage_vsel operation, saving some code.
114 */
115int regulator_get_voltage_sel_regmap(struct regulator_dev *rdev)
116{
117	unsigned int val;
118	int ret;
119
120	ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
121	if (ret != 0)
122		return ret;
123
124	val &= rdev->desc->vsel_mask;
125	val >>= ffs(rdev->desc->vsel_mask) - 1;
126
127	return val;
128}
129EXPORT_SYMBOL_GPL(regulator_get_voltage_sel_regmap);
130
131/**
132 * regulator_set_voltage_sel_regmap - standard set_voltage_sel for regmap users
133 *
134 * @rdev: regulator to operate on
135 * @sel: Selector to set
136 *
137 * Regulators that use regmap for their register I/O can set the
138 * vsel_reg and vsel_mask fields in their descriptor and then use this
139 * as their set_voltage_vsel operation, saving some code.
140 */
141int regulator_set_voltage_sel_regmap(struct regulator_dev *rdev, unsigned sel)
142{
143	int ret;
144
145	sel <<= ffs(rdev->desc->vsel_mask) - 1;
146
147	ret = regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
148				  rdev->desc->vsel_mask, sel);
149	if (ret)
150		return ret;
151
152	if (rdev->desc->apply_bit)
153		ret = regmap_update_bits(rdev->regmap, rdev->desc->apply_reg,
154					 rdev->desc->apply_bit,
155					 rdev->desc->apply_bit);
156	return ret;
157}
158EXPORT_SYMBOL_GPL(regulator_set_voltage_sel_regmap);
159
160/**
161 * regulator_map_voltage_iterate - map_voltage() based on list_voltage()
162 *
163 * @rdev: Regulator to operate on
164 * @min_uV: Lower bound for voltage
165 * @max_uV: Upper bound for voltage
166 *
167 * Drivers implementing set_voltage_sel() and list_voltage() can use
168 * this as their map_voltage() operation.  It will find a suitable
169 * voltage by calling list_voltage() until it gets something in bounds
170 * for the requested voltages.
171 */
172int regulator_map_voltage_iterate(struct regulator_dev *rdev,
173				  int min_uV, int max_uV)
174{
175	int best_val = INT_MAX;
176	int selector = 0;
177	int i, ret;
178
179	/* Find the smallest voltage that falls within the specified
180	 * range.
181	 */
182	for (i = 0; i < rdev->desc->n_voltages; i++) {
183		ret = rdev->desc->ops->list_voltage(rdev, i);
184		if (ret < 0)
185			continue;
186
187		if (ret < best_val && ret >= min_uV && ret <= max_uV) {
188			best_val = ret;
189			selector = i;
190		}
191	}
192
193	if (best_val != INT_MAX)
194		return selector;
195	else
196		return -EINVAL;
197}
198EXPORT_SYMBOL_GPL(regulator_map_voltage_iterate);
199
200/**
201 * regulator_map_voltage_ascend - map_voltage() for ascendant voltage list
202 *
203 * @rdev: Regulator to operate on
204 * @min_uV: Lower bound for voltage
205 * @max_uV: Upper bound for voltage
206 *
207 * Drivers that have ascendant voltage list can use this as their
208 * map_voltage() operation.
209 */
210int regulator_map_voltage_ascend(struct regulator_dev *rdev,
211				 int min_uV, int max_uV)
212{
213	int i, ret;
214
215	for (i = 0; i < rdev->desc->n_voltages; i++) {
216		ret = rdev->desc->ops->list_voltage(rdev, i);
217		if (ret < 0)
218			continue;
219
220		if (ret > max_uV)
221			break;
222
223		if (ret >= min_uV && ret <= max_uV)
224			return i;
225	}
226
227	return -EINVAL;
228}
229EXPORT_SYMBOL_GPL(regulator_map_voltage_ascend);
230
231/**
232 * regulator_map_voltage_linear - map_voltage() for simple linear mappings
233 *
234 * @rdev: Regulator to operate on
235 * @min_uV: Lower bound for voltage
236 * @max_uV: Upper bound for voltage
237 *
238 * Drivers providing min_uV and uV_step in their regulator_desc can
239 * use this as their map_voltage() operation.
240 */
241int regulator_map_voltage_linear(struct regulator_dev *rdev,
242				 int min_uV, int max_uV)
243{
244	int ret, voltage;
245
246	/* Allow uV_step to be 0 for fixed voltage */
247	if (rdev->desc->n_voltages == 1 && rdev->desc->uV_step == 0) {
248		if (min_uV <= rdev->desc->min_uV && rdev->desc->min_uV <= max_uV)
249			return 0;
250		else
251			return -EINVAL;
252	}
253
254	if (!rdev->desc->uV_step) {
255		BUG_ON(!rdev->desc->uV_step);
256		return -EINVAL;
257	}
258
259	if (min_uV < rdev->desc->min_uV)
260		min_uV = rdev->desc->min_uV;
261
262	ret = DIV_ROUND_UP(min_uV - rdev->desc->min_uV, rdev->desc->uV_step);
263	if (ret < 0)
264		return ret;
265
266	ret += rdev->desc->linear_min_sel;
267
268	/* Map back into a voltage to verify we're still in bounds */
269	voltage = rdev->desc->ops->list_voltage(rdev, ret);
270	if (voltage < min_uV || voltage > max_uV)
271		return -EINVAL;
272
273	return ret;
274}
275EXPORT_SYMBOL_GPL(regulator_map_voltage_linear);
276
277/**
278 * regulator_map_voltage_linear - map_voltage() for multiple linear ranges
279 *
280 * @rdev: Regulator to operate on
281 * @min_uV: Lower bound for voltage
282 * @max_uV: Upper bound for voltage
283 *
284 * Drivers providing linear_ranges in their descriptor can use this as
285 * their map_voltage() callback.
286 */
287int regulator_map_voltage_linear_range(struct regulator_dev *rdev,
288				       int min_uV, int max_uV)
289{
290	const struct regulator_linear_range *range;
291	int ret = -EINVAL;
292	int voltage, i;
293
294	if (!rdev->desc->n_linear_ranges) {
295		BUG_ON(!rdev->desc->n_linear_ranges);
296		return -EINVAL;
297	}
298
299	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {
300		int linear_max_uV;
301
302		range = &rdev->desc->linear_ranges[i];
303		linear_max_uV = range->min_uV +
304			(range->max_sel - range->min_sel) * range->uV_step;
305
306		if (!(min_uV <= linear_max_uV && max_uV >= range->min_uV))
307			continue;
308
309		if (min_uV <= range->min_uV)
310			min_uV = range->min_uV;
311
312		/* range->uV_step == 0 means fixed voltage range */
313		if (range->uV_step == 0) {
314			ret = 0;
315		} else {
316			ret = DIV_ROUND_UP(min_uV - range->min_uV,
317					   range->uV_step);
318			if (ret < 0)
319				return ret;
320		}
321
322		ret += range->min_sel;
323
324		break;
325	}
326
327	if (i == rdev->desc->n_linear_ranges)
328		return -EINVAL;
329
330	/* Map back into a voltage to verify we're still in bounds */
331	voltage = rdev->desc->ops->list_voltage(rdev, ret);
332	if (voltage < min_uV || voltage > max_uV)
333		return -EINVAL;
334
335	return ret;
336}
337EXPORT_SYMBOL_GPL(regulator_map_voltage_linear_range);
338
339/**
340 * regulator_list_voltage_linear - List voltages with simple calculation
341 *
342 * @rdev: Regulator device
343 * @selector: Selector to convert into a voltage
344 *
345 * Regulators with a simple linear mapping between voltages and
346 * selectors can set min_uV and uV_step in the regulator descriptor
347 * and then use this function as their list_voltage() operation,
348 */
349int regulator_list_voltage_linear(struct regulator_dev *rdev,
350				  unsigned int selector)
351{
352	if (selector >= rdev->desc->n_voltages)
353		return -EINVAL;
354	if (selector < rdev->desc->linear_min_sel)
355		return 0;
356
357	selector -= rdev->desc->linear_min_sel;
358
359	return rdev->desc->min_uV + (rdev->desc->uV_step * selector);
360}
361EXPORT_SYMBOL_GPL(regulator_list_voltage_linear);
362
363/**
364 * regulator_list_voltage_linear_range - List voltages for linear ranges
365 *
366 * @rdev: Regulator device
367 * @selector: Selector to convert into a voltage
368 *
369 * Regulators with a series of simple linear mappings between voltages
370 * and selectors can set linear_ranges in the regulator descriptor and
371 * then use this function as their list_voltage() operation,
372 */
373int regulator_list_voltage_linear_range(struct regulator_dev *rdev,
374					unsigned int selector)
375{
376	const struct regulator_linear_range *range;
377	int i;
378
379	if (!rdev->desc->n_linear_ranges) {
380		BUG_ON(!rdev->desc->n_linear_ranges);
381		return -EINVAL;
382	}
383
384	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {
385		range = &rdev->desc->linear_ranges[i];
386
387		if (!(selector >= range->min_sel &&
388		      selector <= range->max_sel))
389			continue;
390
391		selector -= range->min_sel;
392
393		return range->min_uV + (range->uV_step * selector);
394	}
395
396	return -EINVAL;
397}
398EXPORT_SYMBOL_GPL(regulator_list_voltage_linear_range);
399
400/**
401 * regulator_list_voltage_table - List voltages with table based mapping
402 *
403 * @rdev: Regulator device
404 * @selector: Selector to convert into a voltage
405 *
406 * Regulators with table based mapping between voltages and
407 * selectors can set volt_table in the regulator descriptor
408 * and then use this function as their list_voltage() operation.
409 */
410int regulator_list_voltage_table(struct regulator_dev *rdev,
411				 unsigned int selector)
412{
413	if (!rdev->desc->volt_table) {
414		BUG_ON(!rdev->desc->volt_table);
415		return -EINVAL;
416	}
417
418	if (selector >= rdev->desc->n_voltages)
419		return -EINVAL;
420
421	return rdev->desc->volt_table[selector];
422}
423EXPORT_SYMBOL_GPL(regulator_list_voltage_table);
424
425/**
426 * regulator_set_bypass_regmap - Default set_bypass() using regmap
427 *
428 * @rdev: device to operate on.
429 * @enable: state to set.
430 */
431int regulator_set_bypass_regmap(struct regulator_dev *rdev, bool enable)
432{
433	unsigned int val;
434
435	if (enable) {
436		val = rdev->desc->bypass_val_on;
437		if (!val)
438			val = rdev->desc->bypass_mask;
439	} else {
440		val = rdev->desc->bypass_val_off;
441	}
442
443	return regmap_update_bits(rdev->regmap, rdev->desc->bypass_reg,
444				  rdev->desc->bypass_mask, val);
445}
446EXPORT_SYMBOL_GPL(regulator_set_bypass_regmap);
447
448/**
449 * regulator_get_bypass_regmap - Default get_bypass() using regmap
450 *
451 * @rdev: device to operate on.
452 * @enable: current state.
453 */
454int regulator_get_bypass_regmap(struct regulator_dev *rdev, bool *enable)
455{
456	unsigned int val;
457	int ret;
458
459	ret = regmap_read(rdev->regmap, rdev->desc->bypass_reg, &val);
460	if (ret != 0)
461		return ret;
462
463	*enable = val & rdev->desc->bypass_mask;
464
465	return 0;
466}
467EXPORT_SYMBOL_GPL(regulator_get_bypass_regmap);
468