xref: /linux/drivers/regulator/max8998.c (revision 6e7fd890f1d6ac83805409e9c346240de2705584)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // max8998.c - Voltage regulator driver for the Maxim 8998
4 //
5 //  Copyright (C) 2009-2010 Samsung Electronics
6 //  Kyungmin Park <kyungmin.park@samsung.com>
7 //  Marek Szyprowski <m.szyprowski@samsung.com>
8 
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/i2c.h>
12 #include <linux/err.h>
13 #include <linux/bits.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/slab.h>
16 #include <linux/interrupt.h>
17 #include <linux/mutex.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/regulator/driver.h>
21 #include <linux/regulator/of_regulator.h>
22 #include <linux/mfd/max8998.h>
23 #include <linux/mfd/max8998-private.h>
24 
25 struct max8998_data {
26 	struct device		*dev;
27 	struct max8998_dev	*iodev;
28 	int			num_regulators;
29 	u8                      buck1_vol[4]; /* voltages for selection */
30 	u8                      buck2_vol[2];
31 	unsigned int		buck1_idx; /* index to last changed voltage */
32 					   /* value in a set */
33 	unsigned int		buck2_idx;
34 	struct gpio_desc	*buck1_gpio1;
35 	struct gpio_desc	*buck1_gpio2;
36 	struct gpio_desc	*buck2_gpio;
37 };
38 
39 static const unsigned int charger_current_table[] = {
40 	90000, 380000, 475000, 550000, 570000, 600000, 700000, 800000,
41 };
42 
43 static int max8998_get_enable_register(struct regulator_dev *rdev,
44 					int *reg, int *shift)
45 {
46 	int ldo = rdev_get_id(rdev);
47 
48 	switch (ldo) {
49 	case MAX8998_LDO2 ... MAX8998_LDO5:
50 		*reg = MAX8998_REG_ONOFF1;
51 		*shift = 3 - (ldo - MAX8998_LDO2);
52 		break;
53 	case MAX8998_LDO6 ... MAX8998_LDO13:
54 		*reg = MAX8998_REG_ONOFF2;
55 		*shift = 7 - (ldo - MAX8998_LDO6);
56 		break;
57 	case MAX8998_LDO14 ... MAX8998_LDO17:
58 		*reg = MAX8998_REG_ONOFF3;
59 		*shift = 7 - (ldo - MAX8998_LDO14);
60 		break;
61 	case MAX8998_BUCK1 ... MAX8998_BUCK4:
62 		*reg = MAX8998_REG_ONOFF1;
63 		*shift = 7 - (ldo - MAX8998_BUCK1);
64 		break;
65 	case MAX8998_EN32KHZ_AP ... MAX8998_ENVICHG:
66 		*reg = MAX8998_REG_ONOFF4;
67 		*shift = 7 - (ldo - MAX8998_EN32KHZ_AP);
68 		break;
69 	case MAX8998_ESAFEOUT1 ... MAX8998_ESAFEOUT2:
70 		*reg = MAX8998_REG_CHGR2;
71 		*shift = 7 - (ldo - MAX8998_ESAFEOUT1);
72 		break;
73 	case MAX8998_CHARGER:
74 		*reg = MAX8998_REG_CHGR2;
75 		*shift = 0;
76 		break;
77 	default:
78 		return -EINVAL;
79 	}
80 
81 	return 0;
82 }
83 
84 static int max8998_ldo_is_enabled(struct regulator_dev *rdev)
85 {
86 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
87 	struct i2c_client *i2c = max8998->iodev->i2c;
88 	int ret, reg, shift = 8;
89 	u8 val;
90 
91 	ret = max8998_get_enable_register(rdev, &reg, &shift);
92 	if (ret)
93 		return ret;
94 
95 	ret = max8998_read_reg(i2c, reg, &val);
96 	if (ret)
97 		return ret;
98 
99 	return val & (1 << shift);
100 }
101 
102 static int max8998_ldo_is_enabled_inverted(struct regulator_dev *rdev)
103 {
104 	return (!max8998_ldo_is_enabled(rdev));
105 }
106 
107 static int max8998_ldo_enable(struct regulator_dev *rdev)
108 {
109 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
110 	struct i2c_client *i2c = max8998->iodev->i2c;
111 	int reg, shift = 8, ret;
112 
113 	ret = max8998_get_enable_register(rdev, &reg, &shift);
114 	if (ret)
115 		return ret;
116 
117 	return max8998_update_reg(i2c, reg, 1<<shift, 1<<shift);
118 }
119 
120 static int max8998_ldo_disable(struct regulator_dev *rdev)
121 {
122 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
123 	struct i2c_client *i2c = max8998->iodev->i2c;
124 	int reg, shift = 8, ret;
125 
126 	ret = max8998_get_enable_register(rdev, &reg, &shift);
127 	if (ret)
128 		return ret;
129 
130 	return max8998_update_reg(i2c, reg, 0, 1<<shift);
131 }
132 
133 static int max8998_get_voltage_register(struct regulator_dev *rdev,
134 				int *_reg, int *_shift, int *_mask)
135 {
136 	int ldo = rdev_get_id(rdev);
137 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
138 	int reg, shift = 0, mask = 0xff;
139 
140 	switch (ldo) {
141 	case MAX8998_LDO2 ... MAX8998_LDO3:
142 		reg = MAX8998_REG_LDO2_LDO3;
143 		mask = 0xf;
144 		if (ldo == MAX8998_LDO2)
145 			shift = 4;
146 		else
147 			shift = 0;
148 		break;
149 	case MAX8998_LDO4 ... MAX8998_LDO7:
150 		reg = MAX8998_REG_LDO4 + (ldo - MAX8998_LDO4);
151 		break;
152 	case MAX8998_LDO8 ... MAX8998_LDO9:
153 		reg = MAX8998_REG_LDO8_LDO9;
154 		mask = 0xf;
155 		if (ldo == MAX8998_LDO8)
156 			shift = 4;
157 		else
158 			shift = 0;
159 		break;
160 	case MAX8998_LDO10 ... MAX8998_LDO11:
161 		reg = MAX8998_REG_LDO10_LDO11;
162 		if (ldo == MAX8998_LDO10) {
163 			shift = 5;
164 			mask = 0x7;
165 		} else {
166 			shift = 0;
167 			mask = 0x1f;
168 		}
169 		break;
170 	case MAX8998_LDO12 ... MAX8998_LDO17:
171 		reg = MAX8998_REG_LDO12 + (ldo - MAX8998_LDO12);
172 		break;
173 	case MAX8998_BUCK1:
174 		reg = MAX8998_REG_BUCK1_VOLTAGE1 + max8998->buck1_idx;
175 		break;
176 	case MAX8998_BUCK2:
177 		reg = MAX8998_REG_BUCK2_VOLTAGE1 + max8998->buck2_idx;
178 		break;
179 	case MAX8998_BUCK3:
180 		reg = MAX8998_REG_BUCK3;
181 		break;
182 	case MAX8998_BUCK4:
183 		reg = MAX8998_REG_BUCK4;
184 		break;
185 	default:
186 		return -EINVAL;
187 	}
188 
189 	*_reg = reg;
190 	*_shift = shift;
191 	*_mask = mask;
192 
193 	return 0;
194 }
195 
196 static int max8998_get_voltage_sel(struct regulator_dev *rdev)
197 {
198 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
199 	struct i2c_client *i2c = max8998->iodev->i2c;
200 	int reg, shift = 0, mask, ret;
201 	u8 val;
202 
203 	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
204 	if (ret)
205 		return ret;
206 
207 	ret = max8998_read_reg(i2c, reg, &val);
208 	if (ret)
209 		return ret;
210 
211 	val >>= shift;
212 	val &= mask;
213 
214 	return val;
215 }
216 
217 static int max8998_set_voltage_ldo_sel(struct regulator_dev *rdev,
218 				       unsigned selector)
219 {
220 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
221 	struct i2c_client *i2c = max8998->iodev->i2c;
222 	int reg, shift = 0, mask, ret;
223 
224 	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
225 	if (ret)
226 		return ret;
227 
228 	ret = max8998_update_reg(i2c, reg, selector<<shift, mask<<shift);
229 
230 	return ret;
231 }
232 
233 static inline void buck1_gpio_set(struct gpio_desc *gpio1, struct gpio_desc *gpio2, int v)
234 {
235 	gpiod_set_value(gpio1, v & 0x1);
236 	gpiod_set_value(gpio2, (v >> 1) & 0x1);
237 }
238 
239 static inline void buck2_gpio_set(struct gpio_desc *gpio, int v)
240 {
241 	gpiod_set_value(gpio, v & 0x1);
242 }
243 
244 static int max8998_set_voltage_buck_sel(struct regulator_dev *rdev,
245 					unsigned selector)
246 {
247 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
248 	struct max8998_platform_data *pdata = max8998->iodev->pdata;
249 	struct i2c_client *i2c = max8998->iodev->i2c;
250 	int buck = rdev_get_id(rdev);
251 	int reg, shift = 0, mask, ret, j;
252 	static u8 buck1_last_val;
253 
254 	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
255 	if (ret)
256 		return ret;
257 
258 	switch (buck) {
259 	case MAX8998_BUCK1:
260 		dev_dbg(max8998->dev,
261 			"BUCK1, selector:%d, buck1_vol1:%d, buck1_vol2:%d\n"
262 			"buck1_vol3:%d, buck1_vol4:%d\n",
263 			selector, max8998->buck1_vol[0], max8998->buck1_vol[1],
264 			max8998->buck1_vol[2], max8998->buck1_vol[3]);
265 
266 		if (max8998->buck1_gpio1 && max8998->buck1_gpio2) {
267 
268 			/* check if requested voltage */
269 			/* value is already defined */
270 			for (j = 0; j < ARRAY_SIZE(max8998->buck1_vol); j++) {
271 				if (max8998->buck1_vol[j] == selector) {
272 					max8998->buck1_idx = j;
273 					buck1_gpio_set(max8998->buck1_gpio1,
274 						       max8998->buck1_gpio2, j);
275 					goto buck1_exit;
276 				}
277 			}
278 
279 			if (pdata->buck_voltage_lock)
280 				return -EINVAL;
281 
282 			/* no predefine regulator found */
283 			max8998->buck1_idx = (buck1_last_val % 2) + 2;
284 			dev_dbg(max8998->dev, "max8998->buck1_idx:%d\n",
285 				max8998->buck1_idx);
286 			max8998->buck1_vol[max8998->buck1_idx] = selector;
287 			ret = max8998_get_voltage_register(rdev, &reg,
288 							   &shift,
289 							   &mask);
290 			ret = max8998_write_reg(i2c, reg, selector);
291 			buck1_gpio_set(max8998->buck1_gpio1,
292 				       max8998->buck1_gpio2, max8998->buck1_idx);
293 			buck1_last_val++;
294 buck1_exit:
295 			dev_dbg(max8998->dev, "%s: SET1:%d, SET2:%d\n",
296 				i2c->name, gpiod_get_value(max8998->buck1_gpio1),
297 				gpiod_get_value(max8998->buck1_gpio2));
298 			break;
299 		} else {
300 			ret = max8998_write_reg(i2c, reg, selector);
301 		}
302 		break;
303 
304 	case MAX8998_BUCK2:
305 		dev_dbg(max8998->dev,
306 			"BUCK2, selector:%d buck2_vol1:%d, buck2_vol2:%d\n",
307 			selector, max8998->buck2_vol[0], max8998->buck2_vol[1]);
308 		if (max8998->buck2_gpio) {
309 			/* check if requested voltage */
310 			/* value is already defined */
311 			for (j = 0; j < ARRAY_SIZE(max8998->buck2_vol); j++) {
312 				if (max8998->buck2_vol[j] == selector) {
313 					max8998->buck2_idx = j;
314 					buck2_gpio_set(max8998->buck2_gpio, j);
315 					goto buck2_exit;
316 				}
317 			}
318 
319 			if (pdata->buck_voltage_lock)
320 				return -EINVAL;
321 
322 			max8998_get_voltage_register(rdev,
323 					&reg, &shift, &mask);
324 			ret = max8998_write_reg(i2c, reg, selector);
325 			max8998->buck2_vol[max8998->buck2_idx] = selector;
326 			buck2_gpio_set(max8998->buck2_gpio, max8998->buck2_idx);
327 buck2_exit:
328 			dev_dbg(max8998->dev, "%s: SET3:%d\n", i2c->name,
329 				gpiod_get_value(max8998->buck2_gpio));
330 		} else {
331 			ret = max8998_write_reg(i2c, reg, selector);
332 		}
333 		break;
334 
335 	case MAX8998_BUCK3:
336 	case MAX8998_BUCK4:
337 		ret = max8998_update_reg(i2c, reg, selector<<shift,
338 					 mask<<shift);
339 		break;
340 	}
341 
342 	return ret;
343 }
344 
345 static int max8998_set_voltage_buck_time_sel(struct regulator_dev *rdev,
346 					     unsigned int old_selector,
347 					     unsigned int new_selector)
348 {
349 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
350 	struct i2c_client *i2c = max8998->iodev->i2c;
351 	int buck = rdev_get_id(rdev);
352 	u8 val = 0;
353 	int difference, ret;
354 
355 	if (buck < MAX8998_BUCK1 || buck > MAX8998_BUCK4)
356 		return -EINVAL;
357 
358 	/* Voltage stabilization */
359 	ret = max8998_read_reg(i2c, MAX8998_REG_ONOFF4, &val);
360 	if (ret)
361 		return ret;
362 
363 	/* lp3974 hasn't got ENRAMP bit - ramp is assumed as true */
364 	/* MAX8998 has ENRAMP bit implemented, so test it*/
365 	if (max8998->iodev->type == TYPE_MAX8998 && !(val & MAX8998_ENRAMP))
366 		return 0;
367 
368 	difference = (new_selector - old_selector) * rdev->desc->uV_step / 1000;
369 	if (difference > 0)
370 		return DIV_ROUND_UP(difference, (val & 0x0f) + 1);
371 
372 	return 0;
373 }
374 
375 static int max8998_set_current_limit(struct regulator_dev *rdev,
376 				     int min_uA, int max_uA)
377 {
378 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
379 	struct i2c_client *i2c = max8998->iodev->i2c;
380 	unsigned int n_currents = rdev->desc->n_current_limits;
381 	int i, sel = -1;
382 
383 	if (n_currents == 0)
384 		return -EINVAL;
385 
386 	if (rdev->desc->curr_table) {
387 		const unsigned int *curr_table = rdev->desc->curr_table;
388 		bool ascend = curr_table[n_currents - 1] > curr_table[0];
389 
390 		/* search for closest to maximum */
391 		if (ascend) {
392 			for (i = n_currents - 1; i >= 0; i--) {
393 				if (min_uA <= curr_table[i] &&
394 				    curr_table[i] <= max_uA) {
395 					sel = i;
396 					break;
397 				}
398 			}
399 		} else {
400 			for (i = 0; i < n_currents; i++) {
401 				if (min_uA <= curr_table[i] &&
402 				    curr_table[i] <= max_uA) {
403 					sel = i;
404 					break;
405 				}
406 			}
407 		}
408 	}
409 
410 	if (sel < 0)
411 		return -EINVAL;
412 
413 	sel <<= ffs(rdev->desc->csel_mask) - 1;
414 
415 	return max8998_update_reg(i2c, rdev->desc->csel_reg,
416 				  sel, rdev->desc->csel_mask);
417 }
418 
419 static int max8998_get_current_limit(struct regulator_dev *rdev)
420 {
421 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
422 	struct i2c_client *i2c = max8998->iodev->i2c;
423 	u8 val;
424 	int ret;
425 
426 	ret = max8998_read_reg(i2c, rdev->desc->csel_reg, &val);
427 	if (ret != 0)
428 		return ret;
429 
430 	val &= rdev->desc->csel_mask;
431 	val >>= ffs(rdev->desc->csel_mask) - 1;
432 
433 	if (rdev->desc->curr_table) {
434 		if (val >= rdev->desc->n_current_limits)
435 			return -EINVAL;
436 
437 		return rdev->desc->curr_table[val];
438 	}
439 
440 	return -EINVAL;
441 }
442 
443 static const struct regulator_ops max8998_ldo_ops = {
444 	.list_voltage		= regulator_list_voltage_linear,
445 	.map_voltage		= regulator_map_voltage_linear,
446 	.is_enabled		= max8998_ldo_is_enabled,
447 	.enable			= max8998_ldo_enable,
448 	.disable		= max8998_ldo_disable,
449 	.get_voltage_sel	= max8998_get_voltage_sel,
450 	.set_voltage_sel	= max8998_set_voltage_ldo_sel,
451 };
452 
453 static const struct regulator_ops max8998_buck_ops = {
454 	.list_voltage		= regulator_list_voltage_linear,
455 	.map_voltage		= regulator_map_voltage_linear,
456 	.is_enabled		= max8998_ldo_is_enabled,
457 	.enable			= max8998_ldo_enable,
458 	.disable		= max8998_ldo_disable,
459 	.get_voltage_sel	= max8998_get_voltage_sel,
460 	.set_voltage_sel	= max8998_set_voltage_buck_sel,
461 	.set_voltage_time_sel	= max8998_set_voltage_buck_time_sel,
462 };
463 
464 static const struct regulator_ops max8998_charger_ops = {
465 	.set_current_limit	= max8998_set_current_limit,
466 	.get_current_limit	= max8998_get_current_limit,
467 	.is_enabled		= max8998_ldo_is_enabled_inverted,
468 	/* Swapped as register is inverted */
469 	.enable			= max8998_ldo_disable,
470 	.disable		= max8998_ldo_enable,
471 };
472 
473 static const struct regulator_ops max8998_others_ops = {
474 	.is_enabled		= max8998_ldo_is_enabled,
475 	.enable			= max8998_ldo_enable,
476 	.disable		= max8998_ldo_disable,
477 };
478 
479 #define MAX8998_LINEAR_REG(_name, _ops, _min, _step, _max) \
480 	{ \
481 		.name = #_name, \
482 		.id = MAX8998_##_name, \
483 		.ops = _ops, \
484 		.min_uV = (_min), \
485 		.uV_step = (_step), \
486 		.n_voltages = ((_max) - (_min)) / (_step) + 1, \
487 		.type = REGULATOR_VOLTAGE, \
488 		.owner = THIS_MODULE, \
489 	}
490 
491 #define MAX8998_CURRENT_REG(_name, _ops, _table, _reg, _mask) \
492 	{ \
493 		.name = #_name, \
494 		.id = MAX8998_##_name, \
495 		.ops = _ops, \
496 		.curr_table = _table, \
497 		.n_current_limits = ARRAY_SIZE(_table), \
498 		.csel_reg = _reg, \
499 		.csel_mask = _mask, \
500 		.type = REGULATOR_CURRENT, \
501 		.owner = THIS_MODULE, \
502 	}
503 
504 #define MAX8998_OTHERS_REG(_name, _id) \
505 	{ \
506 		.name = #_name, \
507 		.id = _id, \
508 		.ops = &max8998_others_ops, \
509 		.type = REGULATOR_VOLTAGE, \
510 		.owner = THIS_MODULE, \
511 	}
512 
513 static const struct regulator_desc regulators[] = {
514 	MAX8998_LINEAR_REG(LDO2, &max8998_ldo_ops, 800000, 50000, 1300000),
515 	MAX8998_LINEAR_REG(LDO3, &max8998_ldo_ops, 800000, 50000, 1300000),
516 	MAX8998_LINEAR_REG(LDO4, &max8998_ldo_ops, 1600000, 100000, 3600000),
517 	MAX8998_LINEAR_REG(LDO5, &max8998_ldo_ops, 1600000, 100000, 3600000),
518 	MAX8998_LINEAR_REG(LDO6, &max8998_ldo_ops, 1600000, 100000, 3600000),
519 	MAX8998_LINEAR_REG(LDO7, &max8998_ldo_ops, 1600000, 100000, 3600000),
520 	MAX8998_LINEAR_REG(LDO8, &max8998_ldo_ops, 3000000, 100000, 3600000),
521 	MAX8998_LINEAR_REG(LDO9, &max8998_ldo_ops, 2800000, 100000, 3100000),
522 	MAX8998_LINEAR_REG(LDO10, &max8998_ldo_ops, 950000, 50000, 1300000),
523 	MAX8998_LINEAR_REG(LDO11, &max8998_ldo_ops, 1600000, 100000, 3600000),
524 	MAX8998_LINEAR_REG(LDO12, &max8998_ldo_ops, 800000, 100000, 3300000),
525 	MAX8998_LINEAR_REG(LDO13, &max8998_ldo_ops, 800000, 100000, 3300000),
526 	MAX8998_LINEAR_REG(LDO14, &max8998_ldo_ops, 1200000, 100000, 3300000),
527 	MAX8998_LINEAR_REG(LDO15, &max8998_ldo_ops, 1200000, 100000, 3300000),
528 	MAX8998_LINEAR_REG(LDO16, &max8998_ldo_ops, 1600000, 100000, 3600000),
529 	MAX8998_LINEAR_REG(LDO17, &max8998_ldo_ops, 1600000, 100000, 3600000),
530 	MAX8998_LINEAR_REG(BUCK1, &max8998_buck_ops, 750000, 25000, 1525000),
531 	MAX8998_LINEAR_REG(BUCK2, &max8998_buck_ops, 750000, 25000, 1525000),
532 	MAX8998_LINEAR_REG(BUCK3, &max8998_buck_ops, 1600000, 100000, 3600000),
533 	MAX8998_LINEAR_REG(BUCK4, &max8998_buck_ops, 800000, 100000, 2300000),
534 	MAX8998_OTHERS_REG(EN32KHz-AP, MAX8998_EN32KHZ_AP),
535 	MAX8998_OTHERS_REG(EN32KHz-CP, MAX8998_EN32KHZ_CP),
536 	MAX8998_OTHERS_REG(ENVICHG, MAX8998_ENVICHG),
537 	MAX8998_OTHERS_REG(ESAFEOUT1, MAX8998_ESAFEOUT1),
538 	MAX8998_OTHERS_REG(ESAFEOUT2, MAX8998_ESAFEOUT2),
539 	MAX8998_CURRENT_REG(CHARGER, &max8998_charger_ops,
540 			    charger_current_table, MAX8998_REG_CHGR1, 0x7),
541 };
542 
543 static int max8998_pmic_dt_parse_pdata(struct max8998_dev *iodev,
544 					struct max8998_platform_data *pdata)
545 {
546 	struct device_node *pmic_np = iodev->dev->of_node;
547 	struct device_node *regulators_np, *reg_np;
548 	struct max8998_regulator_data *rdata;
549 	unsigned int i;
550 	int ret;
551 
552 	regulators_np = of_get_child_by_name(pmic_np, "regulators");
553 	if (!regulators_np) {
554 		dev_err(iodev->dev, "could not find regulators sub-node\n");
555 		return -EINVAL;
556 	}
557 
558 	/* count the number of regulators to be supported in pmic */
559 	pdata->num_regulators = of_get_child_count(regulators_np);
560 
561 	rdata = devm_kcalloc(iodev->dev,
562 			     pdata->num_regulators, sizeof(*rdata),
563 			     GFP_KERNEL);
564 	if (!rdata) {
565 		of_node_put(regulators_np);
566 		return -ENOMEM;
567 	}
568 
569 	pdata->regulators = rdata;
570 	for (i = 0; i < ARRAY_SIZE(regulators); ++i) {
571 		reg_np = of_get_child_by_name(regulators_np,
572 							regulators[i].name);
573 		if (!reg_np)
574 			continue;
575 
576 		rdata->id = regulators[i].id;
577 		rdata->initdata = of_get_regulator_init_data(iodev->dev,
578 							     reg_np,
579 							     &regulators[i]);
580 		rdata->reg_node = reg_np;
581 		++rdata;
582 	}
583 	pdata->num_regulators = rdata - pdata->regulators;
584 
585 	of_node_put(reg_np);
586 	of_node_put(regulators_np);
587 
588 	pdata->buck_voltage_lock = of_property_read_bool(pmic_np, "max8998,pmic-buck-voltage-lock");
589 
590 	ret = of_property_read_u32(pmic_np,
591 					"max8998,pmic-buck1-default-dvs-idx",
592 					&pdata->buck1_default_idx);
593 	if (!ret && pdata->buck1_default_idx >= 4) {
594 		pdata->buck1_default_idx = 0;
595 		dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
596 	}
597 
598 	ret = of_property_read_u32(pmic_np,
599 					"max8998,pmic-buck2-default-dvs-idx",
600 					&pdata->buck2_default_idx);
601 	if (!ret && pdata->buck2_default_idx >= 2) {
602 		pdata->buck2_default_idx = 0;
603 		dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
604 	}
605 
606 	ret = of_property_read_u32_array(pmic_np,
607 					"max8998,pmic-buck1-dvs-voltage",
608 					pdata->buck1_voltage,
609 					ARRAY_SIZE(pdata->buck1_voltage));
610 	if (ret) {
611 		dev_err(iodev->dev, "buck1 voltages not specified\n");
612 		return -EINVAL;
613 	}
614 
615 	ret = of_property_read_u32_array(pmic_np,
616 					"max8998,pmic-buck2-dvs-voltage",
617 					pdata->buck2_voltage,
618 					ARRAY_SIZE(pdata->buck2_voltage));
619 	if (ret) {
620 		dev_err(iodev->dev, "buck2 voltages not specified\n");
621 		return -EINVAL;
622 	}
623 
624 	return 0;
625 }
626 
627 static int max8998_pmic_probe(struct platform_device *pdev)
628 {
629 	struct max8998_dev *iodev = dev_get_drvdata(pdev->dev.parent);
630 	struct max8998_platform_data *pdata = iodev->pdata;
631 	struct regulator_config config = { };
632 	struct regulator_dev *rdev;
633 	struct max8998_data *max8998;
634 	struct i2c_client *i2c;
635 	enum gpiod_flags flags;
636 	int i, ret;
637 	unsigned int v;
638 
639 	if (!pdata) {
640 		dev_err(pdev->dev.parent, "No platform init data supplied\n");
641 		return -ENODEV;
642 	}
643 
644 	if (IS_ENABLED(CONFIG_OF) && iodev->dev->of_node) {
645 		ret = max8998_pmic_dt_parse_pdata(iodev, pdata);
646 		if (ret)
647 			return ret;
648 	}
649 
650 	max8998 = devm_kzalloc(&pdev->dev, sizeof(struct max8998_data),
651 			       GFP_KERNEL);
652 	if (!max8998)
653 		return -ENOMEM;
654 
655 	max8998->dev = &pdev->dev;
656 	max8998->iodev = iodev;
657 	max8998->num_regulators = pdata->num_regulators;
658 	platform_set_drvdata(pdev, max8998);
659 	i2c = max8998->iodev->i2c;
660 
661 	max8998->buck1_idx = pdata->buck1_default_idx;
662 	max8998->buck2_idx = pdata->buck2_default_idx;
663 
664 	/* Check if MAX8998 voltage selection GPIOs are defined */
665 	flags = (max8998->buck1_idx & BIT(0)) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
666 	max8998->buck1_gpio1 = devm_gpiod_get_index_optional(iodev->dev,
667 							     "max8998,pmic-buck1-dvs",
668 							     0,
669 							     flags);
670 	if (IS_ERR(max8998->buck1_gpio1))
671 		return dev_err_probe(&pdev->dev, PTR_ERR(max8998->buck1_gpio1),
672 				     "could not get BUCK1 GPIO1\n");
673 	gpiod_set_consumer_name(max8998->buck1_gpio1, "MAX8998 BUCK1_SET1");
674 
675 	flags = (max8998->buck1_idx & BIT(1)) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
676 	max8998->buck1_gpio2 = devm_gpiod_get_index_optional(iodev->dev,
677 							     "max8998,pmic-buck1-dvs",
678 							     1,
679 							     flags);
680 	if (IS_ERR(max8998->buck1_gpio2))
681 		return dev_err_probe(&pdev->dev, PTR_ERR(max8998->buck1_gpio2),
682 				     "could not get BUCK1 GPIO2\n");
683 	gpiod_set_consumer_name(max8998->buck1_gpio1, "MAX8998 BUCK1_SET2");
684 
685 	flags = (max8998->buck2_idx & BIT(0)) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
686 	max8998->buck2_gpio = devm_gpiod_get_index_optional(iodev->dev,
687 							     "max8998,pmic-buck2-dvs",
688 							     0,
689 							     flags);
690 	if (IS_ERR(max8998->buck2_gpio))
691 		return dev_err_probe(&pdev->dev, PTR_ERR(max8998->buck2_gpio),
692 				     "could not get BUCK2 GPIO\n");
693 	gpiod_set_consumer_name(max8998->buck1_gpio1, "MAX8998 BUCK2_SET3");
694 
695 	if (max8998->buck1_gpio1 && max8998->buck1_gpio2) {
696 		/* Set predefined values for BUCK1 registers */
697 		for (v = 0; v < ARRAY_SIZE(pdata->buck1_voltage); ++v) {
698 			int index = MAX8998_BUCK1 - MAX8998_LDO2;
699 
700 			i = 0;
701 			while (regulators[index].min_uV +
702 			       regulators[index].uV_step * i
703 			       < pdata->buck1_voltage[v])
704 				i++;
705 
706 			max8998->buck1_vol[v] = i;
707 			ret = max8998_write_reg(i2c,
708 					MAX8998_REG_BUCK1_VOLTAGE1 + v, i);
709 			if (ret)
710 				return ret;
711 		}
712 	}
713 
714 	if (max8998->buck2_gpio) {
715 		/* Set predefined values for BUCK2 registers */
716 		for (v = 0; v < ARRAY_SIZE(pdata->buck2_voltage); ++v) {
717 			int index = MAX8998_BUCK2 - MAX8998_LDO2;
718 
719 			i = 0;
720 			while (regulators[index].min_uV +
721 			       regulators[index].uV_step * i
722 			       < pdata->buck2_voltage[v])
723 				i++;
724 
725 			max8998->buck2_vol[v] = i;
726 			ret = max8998_write_reg(i2c,
727 					MAX8998_REG_BUCK2_VOLTAGE1 + v, i);
728 			if (ret)
729 				return ret;
730 		}
731 	}
732 
733 	for (i = 0; i < pdata->num_regulators; i++) {
734 		int index = pdata->regulators[i].id - MAX8998_LDO2;
735 
736 		config.dev = max8998->dev;
737 		config.of_node = pdata->regulators[i].reg_node;
738 		config.init_data = pdata->regulators[i].initdata;
739 		config.driver_data = max8998;
740 
741 		rdev = devm_regulator_register(&pdev->dev, &regulators[index],
742 					       &config);
743 		if (IS_ERR(rdev)) {
744 			ret = PTR_ERR(rdev);
745 			dev_err(max8998->dev, "regulator %s init failed (%d)\n",
746 						regulators[index].name, ret);
747 			return ret;
748 		}
749 	}
750 
751 	return 0;
752 }
753 
754 static const struct platform_device_id max8998_pmic_id[] = {
755 	{ "max8998-pmic", TYPE_MAX8998 },
756 	{ "lp3974-pmic", TYPE_LP3974 },
757 	{ }
758 };
759 MODULE_DEVICE_TABLE(platform, max8998_pmic_id);
760 
761 static struct platform_driver max8998_pmic_driver = {
762 	.driver = {
763 		.name = "max8998-pmic",
764 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
765 	},
766 	.probe = max8998_pmic_probe,
767 	.id_table = max8998_pmic_id,
768 };
769 
770 static int __init max8998_pmic_init(void)
771 {
772 	return platform_driver_register(&max8998_pmic_driver);
773 }
774 subsys_initcall(max8998_pmic_init);
775 
776 static void __exit max8998_pmic_cleanup(void)
777 {
778 	platform_driver_unregister(&max8998_pmic_driver);
779 }
780 module_exit(max8998_pmic_cleanup);
781 
782 MODULE_DESCRIPTION("MAXIM 8998 voltage regulator driver");
783 MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
784 MODULE_LICENSE("GPL");
785