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Linus Walleijd619bc12009-09-09 11:31:00 +02001/*
2 * drivers/regulator/ab3100.c
3 *
4 * Copyright (C) 2008-2009 ST-Ericsson AB
5 * License terms: GNU General Public License (GPL) version 2
6 * Low-level control of the AB3100 IC Low Dropout (LDO)
7 * regulators, external regulator and buck converter
8 * Author: Mattias Wallin <mattias.wallin@stericsson.com>
9 * Author: Linus Walleij <linus.walleij@stericsson.com>
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/err.h>
16#include <linux/delay.h>
17#include <linux/platform_device.h>
18#include <linux/regulator/driver.h>
19#include <linux/mfd/ab3100.h>
20
21/* LDO registers and some handy masking definitions for AB3100 */
22#define AB3100_LDO_A 0x40
23#define AB3100_LDO_C 0x41
24#define AB3100_LDO_D 0x42
25#define AB3100_LDO_E 0x43
26#define AB3100_LDO_E_SLEEP 0x44
27#define AB3100_LDO_F 0x45
28#define AB3100_LDO_G 0x46
29#define AB3100_LDO_H 0x47
30#define AB3100_LDO_H_SLEEP_MODE 0
31#define AB3100_LDO_H_SLEEP_EN 2
32#define AB3100_LDO_ON 4
33#define AB3100_LDO_H_VSEL_AC 5
34#define AB3100_LDO_K 0x48
35#define AB3100_LDO_EXT 0x49
36#define AB3100_BUCK 0x4A
37#define AB3100_BUCK_SLEEP 0x4B
38#define AB3100_REG_ON_MASK 0x10
39
40/**
41 * struct ab3100_regulator
42 * A struct passed around the individual regulator functions
43 * @platform_device: platform device holding this regulator
44 * @ab3100: handle to the AB3100 parent chip
45 * @plfdata: AB3100 platform data passed in at probe time
46 * @regreg: regulator register number in the AB3100
47 * @fixed_voltage: a fixed voltage for this regulator, if this
48 * 0 the voltages array is used instead.
49 * @typ_voltages: an array of available typical voltages for
50 * this regulator
51 * @voltages_len: length of the array of available voltages
52 */
53struct ab3100_regulator {
54 struct regulator_dev *rdev;
55 struct ab3100 *ab3100;
56 struct ab3100_platform_data *plfdata;
57 u8 regreg;
58 int fixed_voltage;
59 int const *typ_voltages;
60 u8 voltages_len;
61};
62
63/* The order in which registers are initialized */
64static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = {
65 AB3100_LDO_A,
66 AB3100_LDO_C,
67 AB3100_LDO_E,
68 AB3100_LDO_E_SLEEP,
69 AB3100_LDO_F,
70 AB3100_LDO_G,
71 AB3100_LDO_H,
72 AB3100_LDO_K,
73 AB3100_LDO_EXT,
74 AB3100_BUCK,
75 AB3100_BUCK_SLEEP,
76 AB3100_LDO_D,
77};
78
79/* Preset (hardware defined) voltages for these regulators */
80#define LDO_A_VOLTAGE 2750000
81#define LDO_C_VOLTAGE 2650000
82#define LDO_D_VOLTAGE 2650000
83
Mark Brown9992ef42009-10-22 16:31:34 +010084static const int ldo_e_buck_typ_voltages[] = {
Linus Walleijd619bc12009-09-09 11:31:00 +020085 1800000,
86 1400000,
87 1300000,
88 1200000,
89 1100000,
90 1050000,
91 900000,
92};
93
Mark Brown9992ef42009-10-22 16:31:34 +010094static const int ldo_f_typ_voltages[] = {
Linus Walleijd619bc12009-09-09 11:31:00 +020095 1800000,
96 1400000,
97 1300000,
98 1200000,
99 1100000,
100 1050000,
101 2500000,
102 2650000,
103};
104
Mark Brown9992ef42009-10-22 16:31:34 +0100105static const int ldo_g_typ_voltages[] = {
Linus Walleijd619bc12009-09-09 11:31:00 +0200106 2850000,
107 2750000,
108 1800000,
109 1500000,
110};
111
Mark Brown9992ef42009-10-22 16:31:34 +0100112static const int ldo_h_typ_voltages[] = {
Linus Walleijd619bc12009-09-09 11:31:00 +0200113 2750000,
114 1800000,
115 1500000,
116 1200000,
117};
118
Mark Brown9992ef42009-10-22 16:31:34 +0100119static const int ldo_k_typ_voltages[] = {
Linus Walleijd619bc12009-09-09 11:31:00 +0200120 2750000,
121 1800000,
122};
123
124
125/* The regulator devices */
126static struct ab3100_regulator
127ab3100_regulators[AB3100_NUM_REGULATORS] = {
128 {
129 .regreg = AB3100_LDO_A,
130 .fixed_voltage = LDO_A_VOLTAGE,
131 },
132 {
133 .regreg = AB3100_LDO_C,
134 .fixed_voltage = LDO_C_VOLTAGE,
135 },
136 {
137 .regreg = AB3100_LDO_D,
138 .fixed_voltage = LDO_D_VOLTAGE,
139 },
140 {
141 .regreg = AB3100_LDO_E,
142 .typ_voltages = ldo_e_buck_typ_voltages,
143 .voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
144 },
145 {
146 .regreg = AB3100_LDO_F,
147 .typ_voltages = ldo_f_typ_voltages,
148 .voltages_len = ARRAY_SIZE(ldo_f_typ_voltages),
149 },
150 {
151 .regreg = AB3100_LDO_G,
152 .typ_voltages = ldo_g_typ_voltages,
153 .voltages_len = ARRAY_SIZE(ldo_g_typ_voltages),
154 },
155 {
156 .regreg = AB3100_LDO_H,
157 .typ_voltages = ldo_h_typ_voltages,
158 .voltages_len = ARRAY_SIZE(ldo_h_typ_voltages),
159 },
160 {
161 .regreg = AB3100_LDO_K,
162 .typ_voltages = ldo_k_typ_voltages,
163 .voltages_len = ARRAY_SIZE(ldo_k_typ_voltages),
164 },
165 {
166 .regreg = AB3100_LDO_EXT,
167 /* No voltages for the external regulator */
168 },
169 {
170 .regreg = AB3100_BUCK,
171 .typ_voltages = ldo_e_buck_typ_voltages,
172 .voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages),
173 },
174};
175
176/*
177 * General functions for enable, disable and is_enabled used for
178 * LDO: A,C,E,F,G,H,K,EXT and BUCK
179 */
180static int ab3100_enable_regulator(struct regulator_dev *reg)
181{
182 struct ab3100_regulator *abreg = reg->reg_data;
183 int err;
184 u8 regval;
185
186 err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
187 &regval);
188 if (err) {
189 dev_warn(&reg->dev, "failed to get regid %d value\n",
190 abreg->regreg);
191 return err;
192 }
193
194 /* The regulator is already on, no reason to go further */
195 if (regval & AB3100_REG_ON_MASK)
196 return 0;
197
198 regval |= AB3100_REG_ON_MASK;
199
200 err = ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
201 regval);
202 if (err) {
203 dev_warn(&reg->dev, "failed to set regid %d value\n",
204 abreg->regreg);
205 return err;
206 }
207
208 /* Per-regulator power on delay from spec */
209 switch (abreg->regreg) {
210 case AB3100_LDO_A: /* Fallthrough */
211 case AB3100_LDO_C: /* Fallthrough */
212 case AB3100_LDO_D: /* Fallthrough */
213 case AB3100_LDO_E: /* Fallthrough */
214 case AB3100_LDO_H: /* Fallthrough */
215 case AB3100_LDO_K:
216 udelay(200);
217 break;
218 case AB3100_LDO_F:
219 udelay(600);
220 break;
221 case AB3100_LDO_G:
222 udelay(400);
223 break;
224 case AB3100_BUCK:
225 mdelay(1);
226 break;
227 default:
228 break;
229 }
230
231 return 0;
232}
233
234static int ab3100_disable_regulator(struct regulator_dev *reg)
235{
236 struct ab3100_regulator *abreg = reg->reg_data;
237 int err;
238 u8 regval;
239
240 /*
241 * LDO D is a special regulator. When it is disabled, the entire
242 * system is shut down. So this is handled specially.
243 */
Linus Walleij176f45b2009-10-28 17:30:15 +0100244 pr_info("Called ab3100_disable_regulator\n");
Linus Walleijd619bc12009-09-09 11:31:00 +0200245 if (abreg->regreg == AB3100_LDO_D) {
Linus Walleijd619bc12009-09-09 11:31:00 +0200246 dev_info(&reg->dev, "disabling LDO D - shut down system\n");
Linus Walleijd619bc12009-09-09 11:31:00 +0200247 /* Setting LDO D to 0x00 cuts the power to the SoC */
248 return ab3100_set_register_interruptible(abreg->ab3100,
249 AB3100_LDO_D, 0x00U);
Linus Walleijd619bc12009-09-09 11:31:00 +0200250 }
251
252 /*
253 * All other regulators are handled here
254 */
255 err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
256 &regval);
257 if (err) {
258 dev_err(&reg->dev, "unable to get register 0x%x\n",
259 abreg->regreg);
260 return err;
261 }
262 regval &= ~AB3100_REG_ON_MASK;
263 return ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg,
264 regval);
265}
266
267static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
268{
269 struct ab3100_regulator *abreg = reg->reg_data;
270 u8 regval;
271 int err;
272
273 err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg,
274 &regval);
275 if (err) {
276 dev_err(&reg->dev, "unable to get register 0x%x\n",
277 abreg->regreg);
278 return err;
279 }
280
281 return regval & AB3100_REG_ON_MASK;
282}
283
284static int ab3100_list_voltage_regulator(struct regulator_dev *reg,
285 unsigned selector)
286{
287 struct ab3100_regulator *abreg = reg->reg_data;
288
289 if (selector > abreg->voltages_len)
290 return -EINVAL;
291 return abreg->typ_voltages[selector];
292}
293
294static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
295{
296 struct ab3100_regulator *abreg = reg->reg_data;
297 u8 regval;
298 int err;
299
300 /* Return the voltage for fixed regulators immediately */
301 if (abreg->fixed_voltage)
302 return abreg->fixed_voltage;
303
304 /*
305 * For variable types, read out setting and index into
306 * supplied voltage list.
307 */
308 err = ab3100_get_register_interruptible(abreg->ab3100,
309 abreg->regreg, &regval);
310 if (err) {
311 dev_warn(&reg->dev,
312 "failed to get regulator value in register %02x\n",
313 abreg->regreg);
314 return err;
315 }
316
317 /* The 3 highest bits index voltages */
318 regval &= 0xE0;
319 regval >>= 5;
320
321 if (regval > abreg->voltages_len) {
322 dev_err(&reg->dev,
323 "regulator register %02x contains an illegal voltage setting\n",
324 abreg->regreg);
325 return -EINVAL;
326 }
327
328 return abreg->typ_voltages[regval];
329}
330
331static int ab3100_get_best_voltage_index(struct regulator_dev *reg,
332 int min_uV, int max_uV)
333{
334 struct ab3100_regulator *abreg = reg->reg_data;
335 int i;
336 int bestmatch;
337 int bestindex;
338
339 /*
340 * Locate the minimum voltage fitting the criteria on
341 * this regulator. The switchable voltages are not
342 * in strict falling order so we need to check them
343 * all for the best match.
344 */
345 bestmatch = INT_MAX;
346 bestindex = -1;
347 for (i = 0; i < abreg->voltages_len; i++) {
348 if (abreg->typ_voltages[i] <= max_uV &&
349 abreg->typ_voltages[i] >= min_uV &&
350 abreg->typ_voltages[i] < bestmatch) {
351 bestmatch = abreg->typ_voltages[i];
352 bestindex = i;
353 }
354 }
355
356 if (bestindex < 0) {
357 dev_warn(&reg->dev, "requested %d<=x<=%d uV, out of range!\n",
358 min_uV, max_uV);
359 return -EINVAL;
360 }
361 return bestindex;
362}
363
364static int ab3100_set_voltage_regulator(struct regulator_dev *reg,
365 int min_uV, int max_uV)
366{
367 struct ab3100_regulator *abreg = reg->reg_data;
368 u8 regval;
369 int err;
370 int bestindex;
371
372 bestindex = ab3100_get_best_voltage_index(reg, min_uV, max_uV);
373 if (bestindex < 0)
374 return bestindex;
375
376 err = ab3100_get_register_interruptible(abreg->ab3100,
377 abreg->regreg, &regval);
378 if (err) {
379 dev_warn(&reg->dev,
380 "failed to get regulator register %02x\n",
381 abreg->regreg);
382 return err;
383 }
384
385 /* The highest three bits control the variable regulators */
386 regval &= ~0xE0;
387 regval |= (bestindex << 5);
388
389 err = ab3100_set_register_interruptible(abreg->ab3100,
390 abreg->regreg, regval);
391 if (err)
392 dev_warn(&reg->dev, "failed to set regulator register %02x\n",
393 abreg->regreg);
394
395 return err;
396}
397
398static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
399 int uV)
400{
401 struct ab3100_regulator *abreg = reg->reg_data;
402 u8 regval;
403 int err;
404 int bestindex;
405 u8 targetreg;
406
407 if (abreg->regreg == AB3100_LDO_E)
408 targetreg = AB3100_LDO_E_SLEEP;
409 else if (abreg->regreg == AB3100_BUCK)
410 targetreg = AB3100_BUCK_SLEEP;
411 else
412 return -EINVAL;
413
414 /* LDO E and BUCK have special suspend voltages you can set */
415 bestindex = ab3100_get_best_voltage_index(reg, uV, uV);
416
417 err = ab3100_get_register_interruptible(abreg->ab3100,
418 targetreg, &regval);
419 if (err) {
420 dev_warn(&reg->dev,
421 "failed to get regulator register %02x\n",
422 targetreg);
423 return err;
424 }
425
426 /* The highest three bits control the variable regulators */
427 regval &= ~0xE0;
428 regval |= (bestindex << 5);
429
430 err = ab3100_set_register_interruptible(abreg->ab3100,
431 targetreg, regval);
432 if (err)
433 dev_warn(&reg->dev, "failed to set regulator register %02x\n",
434 abreg->regreg);
435
436 return err;
437}
438
439/*
440 * The external regulator can just define a fixed voltage.
441 */
442static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
443{
444 struct ab3100_regulator *abreg = reg->reg_data;
445
446 return abreg->plfdata->external_voltage;
447}
448
449static struct regulator_ops regulator_ops_fixed = {
450 .enable = ab3100_enable_regulator,
451 .disable = ab3100_disable_regulator,
452 .is_enabled = ab3100_is_enabled_regulator,
453 .get_voltage = ab3100_get_voltage_regulator,
454};
455
456static struct regulator_ops regulator_ops_variable = {
457 .enable = ab3100_enable_regulator,
458 .disable = ab3100_disable_regulator,
459 .is_enabled = ab3100_is_enabled_regulator,
460 .get_voltage = ab3100_get_voltage_regulator,
461 .set_voltage = ab3100_set_voltage_regulator,
462 .list_voltage = ab3100_list_voltage_regulator,
463};
464
465static struct regulator_ops regulator_ops_variable_sleepable = {
466 .enable = ab3100_enable_regulator,
467 .disable = ab3100_disable_regulator,
468 .is_enabled = ab3100_is_enabled_regulator,
469 .get_voltage = ab3100_get_voltage_regulator,
470 .set_voltage = ab3100_set_voltage_regulator,
471 .set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
472 .list_voltage = ab3100_list_voltage_regulator,
473};
474
475/*
476 * LDO EXT is an external regulator so it is really
477 * not possible to set any voltage locally here, AB3100
478 * is an on/off switch plain an simple. The external
479 * voltage is defined in the board set-up if any.
480 */
481static struct regulator_ops regulator_ops_external = {
482 .enable = ab3100_enable_regulator,
483 .disable = ab3100_disable_regulator,
484 .is_enabled = ab3100_is_enabled_regulator,
485 .get_voltage = ab3100_get_voltage_regulator_external,
486};
487
488static struct regulator_desc
489ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
490 {
491 .name = "LDO_A",
492 .id = AB3100_LDO_A,
493 .ops = &regulator_ops_fixed,
494 .type = REGULATOR_VOLTAGE,
495 },
496 {
497 .name = "LDO_C",
498 .id = AB3100_LDO_C,
499 .ops = &regulator_ops_fixed,
500 .type = REGULATOR_VOLTAGE,
501 },
502 {
503 .name = "LDO_D",
504 .id = AB3100_LDO_D,
505 .ops = &regulator_ops_fixed,
506 .type = REGULATOR_VOLTAGE,
507 },
508 {
509 .name = "LDO_E",
510 .id = AB3100_LDO_E,
511 .ops = &regulator_ops_variable_sleepable,
Linus Walleij75f2ba82009-09-17 09:17:33 +0200512 .n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
Linus Walleijd619bc12009-09-09 11:31:00 +0200513 .type = REGULATOR_VOLTAGE,
514 },
515 {
516 .name = "LDO_F",
517 .id = AB3100_LDO_F,
518 .ops = &regulator_ops_variable,
Linus Walleij75f2ba82009-09-17 09:17:33 +0200519 .n_voltages = ARRAY_SIZE(ldo_f_typ_voltages),
Linus Walleijd619bc12009-09-09 11:31:00 +0200520 .type = REGULATOR_VOLTAGE,
521 },
522 {
523 .name = "LDO_G",
524 .id = AB3100_LDO_G,
525 .ops = &regulator_ops_variable,
Linus Walleij75f2ba82009-09-17 09:17:33 +0200526 .n_voltages = ARRAY_SIZE(ldo_g_typ_voltages),
Linus Walleijd619bc12009-09-09 11:31:00 +0200527 .type = REGULATOR_VOLTAGE,
528 },
529 {
530 .name = "LDO_H",
531 .id = AB3100_LDO_H,
532 .ops = &regulator_ops_variable,
Linus Walleij75f2ba82009-09-17 09:17:33 +0200533 .n_voltages = ARRAY_SIZE(ldo_h_typ_voltages),
Linus Walleijd619bc12009-09-09 11:31:00 +0200534 .type = REGULATOR_VOLTAGE,
535 },
536 {
537 .name = "LDO_K",
538 .id = AB3100_LDO_K,
539 .ops = &regulator_ops_variable,
Linus Walleij75f2ba82009-09-17 09:17:33 +0200540 .n_voltages = ARRAY_SIZE(ldo_k_typ_voltages),
Linus Walleijd619bc12009-09-09 11:31:00 +0200541 .type = REGULATOR_VOLTAGE,
542 },
543 {
544 .name = "LDO_EXT",
545 .id = AB3100_LDO_EXT,
546 .ops = &regulator_ops_external,
547 .type = REGULATOR_VOLTAGE,
548 },
549 {
550 .name = "BUCK",
551 .id = AB3100_BUCK,
552 .ops = &regulator_ops_variable_sleepable,
Linus Walleij75f2ba82009-09-17 09:17:33 +0200553 .n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
Linus Walleijd619bc12009-09-09 11:31:00 +0200554 .type = REGULATOR_VOLTAGE,
555 },
556};
557
558/*
559 * NOTE: the following functions are regulators pluralis - it is the
560 * binding to the AB3100 core driver and the parent platform device
561 * for all the different regulators.
562 */
563
564static int __init ab3100_regulators_probe(struct platform_device *pdev)
565{
566 struct ab3100_platform_data *plfdata = pdev->dev.platform_data;
567 struct ab3100 *ab3100 = platform_get_drvdata(pdev);
568 int err = 0;
569 u8 data;
570 int i;
571
572 /* Check chip state */
573 err = ab3100_get_register_interruptible(ab3100,
574 AB3100_LDO_D, &data);
575 if (err) {
576 dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
577 return err;
578 }
579 if (data & 0x10)
580 dev_notice(&pdev->dev,
581 "chip is already in active mode (Warm start)\n");
582 else
583 dev_notice(&pdev->dev,
584 "chip is in inactive mode (Cold start)\n");
585
586 /* Set up regulators */
587 for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
588 err = ab3100_set_register_interruptible(ab3100,
589 ab3100_reg_init_order[i],
590 plfdata->reg_initvals[i]);
591 if (err) {
592 dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
593 err);
594 return err;
595 }
596 }
597
Linus Walleijd619bc12009-09-09 11:31:00 +0200598 /* Register the regulators */
599 for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
600 struct ab3100_regulator *reg = &ab3100_regulators[i];
601 struct regulator_dev *rdev;
602
603 /*
604 * Initialize per-regulator struct.
605 * Inherit platform data, this comes down from the
606 * i2c boarddata, from the machine. So if you want to
607 * see what it looks like for a certain machine, go
608 * into the machine I2C setup.
609 */
610 reg->ab3100 = ab3100;
611 reg->plfdata = plfdata;
612
613 /*
614 * Register the regulator, pass around
615 * the ab3100_regulator struct
616 */
617 rdev = regulator_register(&ab3100_regulator_desc[i],
618 &pdev->dev,
619 &plfdata->reg_constraints[i],
620 reg);
621
622 if (IS_ERR(rdev)) {
623 err = PTR_ERR(rdev);
624 dev_err(&pdev->dev,
625 "%s: failed to register regulator %s err %d\n",
626 __func__, ab3100_regulator_desc[i].name,
627 err);
628 i--;
629 /* remove the already registered regulators */
630 while (i > 0) {
631 regulator_unregister(ab3100_regulators[i].rdev);
632 i--;
633 }
634 return err;
635 }
636
637 /* Then set a pointer back to the registered regulator */
638 reg->rdev = rdev;
639 }
640
641 return 0;
642}
643
644static int __exit ab3100_regulators_remove(struct platform_device *pdev)
645{
646 int i;
647
648 for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
649 struct ab3100_regulator *reg = &ab3100_regulators[i];
650
651 regulator_unregister(reg->rdev);
652 }
653 return 0;
654}
655
656static struct platform_driver ab3100_regulators_driver = {
657 .driver = {
658 .name = "ab3100-regulators",
659 .owner = THIS_MODULE,
660 },
661 .probe = ab3100_regulators_probe,
662 .remove = __exit_p(ab3100_regulators_remove),
663};
664
665static __init int ab3100_regulators_init(void)
666{
667 return platform_driver_register(&ab3100_regulators_driver);
668}
669
670static __exit void ab3100_regulators_exit(void)
671{
Linus Walleij176f45b2009-10-28 17:30:15 +0100672 platform_driver_unregister(&ab3100_regulators_driver);
Linus Walleijd619bc12009-09-09 11:31:00 +0200673}
674
675subsys_initcall(ab3100_regulators_init);
676module_exit(ab3100_regulators_exit);
677
678MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
679MODULE_DESCRIPTION("AB3100 Regulator driver");
680MODULE_LICENSE("GPL");
681MODULE_ALIAS("platform:ab3100-regulators");