1 /*
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/abx500.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 * @dev: handle to the device
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 */
53 struct ab3100_regulator {
54 struct regulator_dev *rdev;
55 struct device *dev;
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 */
64 static 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
84 static const int ldo_e_buck_typ_voltages[] = {
85 1800000,
86 1400000,
87 1300000,
88 1200000,
89 1100000,
90 1050000,
91 900000,
92 };
93
94 static const int ldo_f_typ_voltages[] = {
95 1800000,
96 1400000,
97 1300000,
98 1200000,
99 1100000,
100 1050000,
101 2500000,
102 2650000,
103 };
104
105 static const int ldo_g_typ_voltages[] = {
106 2850000,
107 2750000,
108 1800000,
109 1500000,
110 };
111
112 static const int ldo_h_typ_voltages[] = {
113 2750000,
114 1800000,
115 1500000,
116 1200000,
117 };
118
119 static const int ldo_k_typ_voltages[] = {
120 2750000,
121 1800000,
122 };
123
124
125 /* The regulator devices */
126 static struct ab3100_regulator
127 ab3100_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 */
ab3100_enable_regulator(struct regulator_dev * reg)180 static 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 = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
187 ®val);
188 if (err) {
189 dev_warn(®->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 = abx500_set_register_interruptible(abreg->dev, 0, abreg->regreg,
201 regval);
202 if (err) {
203 dev_warn(®->dev, "failed to set regid %d value\n",
204 abreg->regreg);
205 return err;
206 }
207
208 return 0;
209 }
210
ab3100_disable_regulator(struct regulator_dev * reg)211 static int ab3100_disable_regulator(struct regulator_dev *reg)
212 {
213 struct ab3100_regulator *abreg = reg->reg_data;
214 int err;
215 u8 regval;
216
217 /*
218 * LDO D is a special regulator. When it is disabled, the entire
219 * system is shut down. So this is handled specially.
220 */
221 pr_info("Called ab3100_disable_regulator\n");
222 if (abreg->regreg == AB3100_LDO_D) {
223 dev_info(®->dev, "disabling LDO D - shut down system\n");
224 /* Setting LDO D to 0x00 cuts the power to the SoC */
225 return abx500_set_register_interruptible(abreg->dev, 0,
226 AB3100_LDO_D, 0x00U);
227 }
228
229 /*
230 * All other regulators are handled here
231 */
232 err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
233 ®val);
234 if (err) {
235 dev_err(®->dev, "unable to get register 0x%x\n",
236 abreg->regreg);
237 return err;
238 }
239 regval &= ~AB3100_REG_ON_MASK;
240 return abx500_set_register_interruptible(abreg->dev, 0, abreg->regreg,
241 regval);
242 }
243
ab3100_is_enabled_regulator(struct regulator_dev * reg)244 static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
245 {
246 struct ab3100_regulator *abreg = reg->reg_data;
247 u8 regval;
248 int err;
249
250 err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
251 ®val);
252 if (err) {
253 dev_err(®->dev, "unable to get register 0x%x\n",
254 abreg->regreg);
255 return err;
256 }
257
258 return regval & AB3100_REG_ON_MASK;
259 }
260
ab3100_list_voltage_regulator(struct regulator_dev * reg,unsigned selector)261 static int ab3100_list_voltage_regulator(struct regulator_dev *reg,
262 unsigned selector)
263 {
264 struct ab3100_regulator *abreg = reg->reg_data;
265
266 if (selector >= abreg->voltages_len)
267 return -EINVAL;
268 return abreg->typ_voltages[selector];
269 }
270
ab3100_get_voltage_regulator(struct regulator_dev * reg)271 static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
272 {
273 struct ab3100_regulator *abreg = reg->reg_data;
274 u8 regval;
275 int err;
276
277 /* Return the voltage for fixed regulators immediately */
278 if (abreg->fixed_voltage)
279 return abreg->fixed_voltage;
280
281 /*
282 * For variable types, read out setting and index into
283 * supplied voltage list.
284 */
285 err = abx500_get_register_interruptible(abreg->dev, 0,
286 abreg->regreg, ®val);
287 if (err) {
288 dev_warn(®->dev,
289 "failed to get regulator value in register %02x\n",
290 abreg->regreg);
291 return err;
292 }
293
294 /* The 3 highest bits index voltages */
295 regval &= 0xE0;
296 regval >>= 5;
297
298 if (regval >= abreg->voltages_len) {
299 dev_err(®->dev,
300 "regulator register %02x contains an illegal voltage setting\n",
301 abreg->regreg);
302 return -EINVAL;
303 }
304
305 return abreg->typ_voltages[regval];
306 }
307
ab3100_get_best_voltage_index(struct regulator_dev * reg,int min_uV,int max_uV)308 static int ab3100_get_best_voltage_index(struct regulator_dev *reg,
309 int min_uV, int max_uV)
310 {
311 struct ab3100_regulator *abreg = reg->reg_data;
312 int i;
313 int bestmatch;
314 int bestindex;
315
316 /*
317 * Locate the minimum voltage fitting the criteria on
318 * this regulator. The switchable voltages are not
319 * in strict falling order so we need to check them
320 * all for the best match.
321 */
322 bestmatch = INT_MAX;
323 bestindex = -1;
324 for (i = 0; i < abreg->voltages_len; i++) {
325 if (abreg->typ_voltages[i] <= max_uV &&
326 abreg->typ_voltages[i] >= min_uV &&
327 abreg->typ_voltages[i] < bestmatch) {
328 bestmatch = abreg->typ_voltages[i];
329 bestindex = i;
330 }
331 }
332
333 if (bestindex < 0) {
334 dev_warn(®->dev, "requested %d<=x<=%d uV, out of range!\n",
335 min_uV, max_uV);
336 return -EINVAL;
337 }
338 return bestindex;
339 }
340
ab3100_set_voltage_regulator(struct regulator_dev * reg,int min_uV,int max_uV,unsigned * selector)341 static int ab3100_set_voltage_regulator(struct regulator_dev *reg,
342 int min_uV, int max_uV,
343 unsigned *selector)
344 {
345 struct ab3100_regulator *abreg = reg->reg_data;
346 u8 regval;
347 int err;
348 int bestindex;
349
350 bestindex = ab3100_get_best_voltage_index(reg, min_uV, max_uV);
351 if (bestindex < 0)
352 return bestindex;
353
354 *selector = bestindex;
355
356 err = abx500_get_register_interruptible(abreg->dev, 0,
357 abreg->regreg, ®val);
358 if (err) {
359 dev_warn(®->dev,
360 "failed to get regulator register %02x\n",
361 abreg->regreg);
362 return err;
363 }
364
365 /* The highest three bits control the variable regulators */
366 regval &= ~0xE0;
367 regval |= (bestindex << 5);
368
369 err = abx500_set_register_interruptible(abreg->dev, 0,
370 abreg->regreg, regval);
371 if (err)
372 dev_warn(®->dev, "failed to set regulator register %02x\n",
373 abreg->regreg);
374
375 return err;
376 }
377
ab3100_set_suspend_voltage_regulator(struct regulator_dev * reg,int uV)378 static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
379 int uV)
380 {
381 struct ab3100_regulator *abreg = reg->reg_data;
382 u8 regval;
383 int err;
384 int bestindex;
385 u8 targetreg;
386
387 if (abreg->regreg == AB3100_LDO_E)
388 targetreg = AB3100_LDO_E_SLEEP;
389 else if (abreg->regreg == AB3100_BUCK)
390 targetreg = AB3100_BUCK_SLEEP;
391 else
392 return -EINVAL;
393
394 /* LDO E and BUCK have special suspend voltages you can set */
395 bestindex = ab3100_get_best_voltage_index(reg, uV, uV);
396
397 err = abx500_get_register_interruptible(abreg->dev, 0,
398 targetreg, ®val);
399 if (err) {
400 dev_warn(®->dev,
401 "failed to get regulator register %02x\n",
402 targetreg);
403 return err;
404 }
405
406 /* The highest three bits control the variable regulators */
407 regval &= ~0xE0;
408 regval |= (bestindex << 5);
409
410 err = abx500_set_register_interruptible(abreg->dev, 0,
411 targetreg, regval);
412 if (err)
413 dev_warn(®->dev, "failed to set regulator register %02x\n",
414 abreg->regreg);
415
416 return err;
417 }
418
419 /*
420 * The external regulator can just define a fixed voltage.
421 */
ab3100_get_voltage_regulator_external(struct regulator_dev * reg)422 static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
423 {
424 struct ab3100_regulator *abreg = reg->reg_data;
425
426 return abreg->plfdata->external_voltage;
427 }
428
ab3100_enable_time_regulator(struct regulator_dev * reg)429 static int ab3100_enable_time_regulator(struct regulator_dev *reg)
430 {
431 struct ab3100_regulator *abreg = reg->reg_data;
432
433 /* Per-regulator power on delay from spec */
434 switch (abreg->regreg) {
435 case AB3100_LDO_A: /* Fallthrough */
436 case AB3100_LDO_C: /* Fallthrough */
437 case AB3100_LDO_D: /* Fallthrough */
438 case AB3100_LDO_E: /* Fallthrough */
439 case AB3100_LDO_H: /* Fallthrough */
440 case AB3100_LDO_K:
441 return 200;
442 case AB3100_LDO_F:
443 return 600;
444 case AB3100_LDO_G:
445 return 400;
446 case AB3100_BUCK:
447 return 1000;
448 default:
449 break;
450 }
451 return 0;
452 }
453
454 static struct regulator_ops regulator_ops_fixed = {
455 .enable = ab3100_enable_regulator,
456 .disable = ab3100_disable_regulator,
457 .is_enabled = ab3100_is_enabled_regulator,
458 .get_voltage = ab3100_get_voltage_regulator,
459 .enable_time = ab3100_enable_time_regulator,
460 };
461
462 static struct regulator_ops regulator_ops_variable = {
463 .enable = ab3100_enable_regulator,
464 .disable = ab3100_disable_regulator,
465 .is_enabled = ab3100_is_enabled_regulator,
466 .get_voltage = ab3100_get_voltage_regulator,
467 .set_voltage = ab3100_set_voltage_regulator,
468 .list_voltage = ab3100_list_voltage_regulator,
469 .enable_time = ab3100_enable_time_regulator,
470 };
471
472 static struct regulator_ops regulator_ops_variable_sleepable = {
473 .enable = ab3100_enable_regulator,
474 .disable = ab3100_disable_regulator,
475 .is_enabled = ab3100_is_enabled_regulator,
476 .get_voltage = ab3100_get_voltage_regulator,
477 .set_voltage = ab3100_set_voltage_regulator,
478 .set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
479 .list_voltage = ab3100_list_voltage_regulator,
480 .enable_time = ab3100_enable_time_regulator,
481 };
482
483 /*
484 * LDO EXT is an external regulator so it is really
485 * not possible to set any voltage locally here, AB3100
486 * is an on/off switch plain an simple. The external
487 * voltage is defined in the board set-up if any.
488 */
489 static struct regulator_ops regulator_ops_external = {
490 .enable = ab3100_enable_regulator,
491 .disable = ab3100_disable_regulator,
492 .is_enabled = ab3100_is_enabled_regulator,
493 .get_voltage = ab3100_get_voltage_regulator_external,
494 };
495
496 static struct regulator_desc
497 ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
498 {
499 .name = "LDO_A",
500 .id = AB3100_LDO_A,
501 .ops = ®ulator_ops_fixed,
502 .type = REGULATOR_VOLTAGE,
503 .owner = THIS_MODULE,
504 },
505 {
506 .name = "LDO_C",
507 .id = AB3100_LDO_C,
508 .ops = ®ulator_ops_fixed,
509 .type = REGULATOR_VOLTAGE,
510 .owner = THIS_MODULE,
511 },
512 {
513 .name = "LDO_D",
514 .id = AB3100_LDO_D,
515 .ops = ®ulator_ops_fixed,
516 .type = REGULATOR_VOLTAGE,
517 .owner = THIS_MODULE,
518 },
519 {
520 .name = "LDO_E",
521 .id = AB3100_LDO_E,
522 .ops = ®ulator_ops_variable_sleepable,
523 .n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
524 .type = REGULATOR_VOLTAGE,
525 .owner = THIS_MODULE,
526 },
527 {
528 .name = "LDO_F",
529 .id = AB3100_LDO_F,
530 .ops = ®ulator_ops_variable,
531 .n_voltages = ARRAY_SIZE(ldo_f_typ_voltages),
532 .type = REGULATOR_VOLTAGE,
533 .owner = THIS_MODULE,
534 },
535 {
536 .name = "LDO_G",
537 .id = AB3100_LDO_G,
538 .ops = ®ulator_ops_variable,
539 .n_voltages = ARRAY_SIZE(ldo_g_typ_voltages),
540 .type = REGULATOR_VOLTAGE,
541 .owner = THIS_MODULE,
542 },
543 {
544 .name = "LDO_H",
545 .id = AB3100_LDO_H,
546 .ops = ®ulator_ops_variable,
547 .n_voltages = ARRAY_SIZE(ldo_h_typ_voltages),
548 .type = REGULATOR_VOLTAGE,
549 .owner = THIS_MODULE,
550 },
551 {
552 .name = "LDO_K",
553 .id = AB3100_LDO_K,
554 .ops = ®ulator_ops_variable,
555 .n_voltages = ARRAY_SIZE(ldo_k_typ_voltages),
556 .type = REGULATOR_VOLTAGE,
557 .owner = THIS_MODULE,
558 },
559 {
560 .name = "LDO_EXT",
561 .id = AB3100_LDO_EXT,
562 .ops = ®ulator_ops_external,
563 .type = REGULATOR_VOLTAGE,
564 .owner = THIS_MODULE,
565 },
566 {
567 .name = "BUCK",
568 .id = AB3100_BUCK,
569 .ops = ®ulator_ops_variable_sleepable,
570 .n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
571 .type = REGULATOR_VOLTAGE,
572 .owner = THIS_MODULE,
573 },
574 };
575
576 /*
577 * NOTE: the following functions are regulators pluralis - it is the
578 * binding to the AB3100 core driver and the parent platform device
579 * for all the different regulators.
580 */
581
ab3100_regulators_probe(struct platform_device * pdev)582 static int __devinit ab3100_regulators_probe(struct platform_device *pdev)
583 {
584 struct ab3100_platform_data *plfdata = pdev->dev.platform_data;
585 int err = 0;
586 u8 data;
587 int i;
588
589 /* Check chip state */
590 err = abx500_get_register_interruptible(&pdev->dev, 0,
591 AB3100_LDO_D, &data);
592 if (err) {
593 dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
594 return err;
595 }
596 if (data & 0x10)
597 dev_notice(&pdev->dev,
598 "chip is already in active mode (Warm start)\n");
599 else
600 dev_notice(&pdev->dev,
601 "chip is in inactive mode (Cold start)\n");
602
603 /* Set up regulators */
604 for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
605 err = abx500_set_register_interruptible(&pdev->dev, 0,
606 ab3100_reg_init_order[i],
607 plfdata->reg_initvals[i]);
608 if (err) {
609 dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
610 err);
611 return err;
612 }
613 }
614
615 /* Register the regulators */
616 for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
617 struct ab3100_regulator *reg = &ab3100_regulators[i];
618 struct regulator_dev *rdev;
619
620 /*
621 * Initialize per-regulator struct.
622 * Inherit platform data, this comes down from the
623 * i2c boarddata, from the machine. So if you want to
624 * see what it looks like for a certain machine, go
625 * into the machine I2C setup.
626 */
627 reg->dev = &pdev->dev;
628 reg->plfdata = plfdata;
629
630 /*
631 * Register the regulator, pass around
632 * the ab3100_regulator struct
633 */
634 rdev = regulator_register(&ab3100_regulator_desc[i],
635 &pdev->dev,
636 &plfdata->reg_constraints[i],
637 reg, NULL);
638
639 if (IS_ERR(rdev)) {
640 err = PTR_ERR(rdev);
641 dev_err(&pdev->dev,
642 "%s: failed to register regulator %s err %d\n",
643 __func__, ab3100_regulator_desc[i].name,
644 err);
645 /* remove the already registered regulators */
646 while (--i >= 0)
647 regulator_unregister(ab3100_regulators[i].rdev);
648 return err;
649 }
650
651 /* Then set a pointer back to the registered regulator */
652 reg->rdev = rdev;
653 }
654
655 return 0;
656 }
657
ab3100_regulators_remove(struct platform_device * pdev)658 static int __devexit ab3100_regulators_remove(struct platform_device *pdev)
659 {
660 int i;
661
662 for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
663 struct ab3100_regulator *reg = &ab3100_regulators[i];
664
665 regulator_unregister(reg->rdev);
666 }
667 return 0;
668 }
669
670 static struct platform_driver ab3100_regulators_driver = {
671 .driver = {
672 .name = "ab3100-regulators",
673 .owner = THIS_MODULE,
674 },
675 .probe = ab3100_regulators_probe,
676 .remove = __devexit_p(ab3100_regulators_remove),
677 };
678
ab3100_regulators_init(void)679 static __init int ab3100_regulators_init(void)
680 {
681 return platform_driver_register(&ab3100_regulators_driver);
682 }
683
ab3100_regulators_exit(void)684 static __exit void ab3100_regulators_exit(void)
685 {
686 platform_driver_unregister(&ab3100_regulators_driver);
687 }
688
689 subsys_initcall(ab3100_regulators_init);
690 module_exit(ab3100_regulators_exit);
691
692 MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
693 MODULE_DESCRIPTION("AB3100 Regulator driver");
694 MODULE_LICENSE("GPL");
695 MODULE_ALIAS("platform:ab3100-regulators");
696