xref: /linux/drivers/regulator/max8998.c (revision 561add0da6d3d07c9bccb0832fb6ed5619167d26)
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/gpio.h>
14 #include <linux/slab.h>
15 #include <linux/interrupt.h>
16 #include <linux/mutex.h>
17 #include <linux/of.h>
18 #include <linux/of_gpio.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 };
35 
36 static const unsigned int charger_current_table[] = {
37 	90000, 380000, 475000, 550000, 570000, 600000, 700000, 800000,
38 };
39 
40 static int max8998_get_enable_register(struct regulator_dev *rdev,
41 					int *reg, int *shift)
42 {
43 	int ldo = rdev_get_id(rdev);
44 
45 	switch (ldo) {
46 	case MAX8998_LDO2 ... MAX8998_LDO5:
47 		*reg = MAX8998_REG_ONOFF1;
48 		*shift = 3 - (ldo - MAX8998_LDO2);
49 		break;
50 	case MAX8998_LDO6 ... MAX8998_LDO13:
51 		*reg = MAX8998_REG_ONOFF2;
52 		*shift = 7 - (ldo - MAX8998_LDO6);
53 		break;
54 	case MAX8998_LDO14 ... MAX8998_LDO17:
55 		*reg = MAX8998_REG_ONOFF3;
56 		*shift = 7 - (ldo - MAX8998_LDO14);
57 		break;
58 	case MAX8998_BUCK1 ... MAX8998_BUCK4:
59 		*reg = MAX8998_REG_ONOFF1;
60 		*shift = 7 - (ldo - MAX8998_BUCK1);
61 		break;
62 	case MAX8998_EN32KHZ_AP ... MAX8998_ENVICHG:
63 		*reg = MAX8998_REG_ONOFF4;
64 		*shift = 7 - (ldo - MAX8998_EN32KHZ_AP);
65 		break;
66 	case MAX8998_ESAFEOUT1 ... MAX8998_ESAFEOUT2:
67 		*reg = MAX8998_REG_CHGR2;
68 		*shift = 7 - (ldo - MAX8998_ESAFEOUT1);
69 		break;
70 	case MAX8998_CHARGER:
71 		*reg = MAX8998_REG_CHGR2;
72 		*shift = 0;
73 		break;
74 	default:
75 		return -EINVAL;
76 	}
77 
78 	return 0;
79 }
80 
81 static int max8998_ldo_is_enabled(struct regulator_dev *rdev)
82 {
83 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
84 	struct i2c_client *i2c = max8998->iodev->i2c;
85 	int ret, reg, shift = 8;
86 	u8 val;
87 
88 	ret = max8998_get_enable_register(rdev, &reg, &shift);
89 	if (ret)
90 		return ret;
91 
92 	ret = max8998_read_reg(i2c, reg, &val);
93 	if (ret)
94 		return ret;
95 
96 	return val & (1 << shift);
97 }
98 
99 static int max8998_ldo_is_enabled_inverted(struct regulator_dev *rdev)
100 {
101 	return (!max8998_ldo_is_enabled(rdev));
102 }
103 
104 static int max8998_ldo_enable(struct regulator_dev *rdev)
105 {
106 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
107 	struct i2c_client *i2c = max8998->iodev->i2c;
108 	int reg, shift = 8, ret;
109 
110 	ret = max8998_get_enable_register(rdev, &reg, &shift);
111 	if (ret)
112 		return ret;
113 
114 	return max8998_update_reg(i2c, reg, 1<<shift, 1<<shift);
115 }
116 
117 static int max8998_ldo_disable(struct regulator_dev *rdev)
118 {
119 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
120 	struct i2c_client *i2c = max8998->iodev->i2c;
121 	int reg, shift = 8, ret;
122 
123 	ret = max8998_get_enable_register(rdev, &reg, &shift);
124 	if (ret)
125 		return ret;
126 
127 	return max8998_update_reg(i2c, reg, 0, 1<<shift);
128 }
129 
130 static int max8998_get_voltage_register(struct regulator_dev *rdev,
131 				int *_reg, int *_shift, int *_mask)
132 {
133 	int ldo = rdev_get_id(rdev);
134 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
135 	int reg, shift = 0, mask = 0xff;
136 
137 	switch (ldo) {
138 	case MAX8998_LDO2 ... MAX8998_LDO3:
139 		reg = MAX8998_REG_LDO2_LDO3;
140 		mask = 0xf;
141 		if (ldo == MAX8998_LDO2)
142 			shift = 4;
143 		else
144 			shift = 0;
145 		break;
146 	case MAX8998_LDO4 ... MAX8998_LDO7:
147 		reg = MAX8998_REG_LDO4 + (ldo - MAX8998_LDO4);
148 		break;
149 	case MAX8998_LDO8 ... MAX8998_LDO9:
150 		reg = MAX8998_REG_LDO8_LDO9;
151 		mask = 0xf;
152 		if (ldo == MAX8998_LDO8)
153 			shift = 4;
154 		else
155 			shift = 0;
156 		break;
157 	case MAX8998_LDO10 ... MAX8998_LDO11:
158 		reg = MAX8998_REG_LDO10_LDO11;
159 		if (ldo == MAX8998_LDO10) {
160 			shift = 5;
161 			mask = 0x7;
162 		} else {
163 			shift = 0;
164 			mask = 0x1f;
165 		}
166 		break;
167 	case MAX8998_LDO12 ... MAX8998_LDO17:
168 		reg = MAX8998_REG_LDO12 + (ldo - MAX8998_LDO12);
169 		break;
170 	case MAX8998_BUCK1:
171 		reg = MAX8998_REG_BUCK1_VOLTAGE1 + max8998->buck1_idx;
172 		break;
173 	case MAX8998_BUCK2:
174 		reg = MAX8998_REG_BUCK2_VOLTAGE1 + max8998->buck2_idx;
175 		break;
176 	case MAX8998_BUCK3:
177 		reg = MAX8998_REG_BUCK3;
178 		break;
179 	case MAX8998_BUCK4:
180 		reg = MAX8998_REG_BUCK4;
181 		break;
182 	default:
183 		return -EINVAL;
184 	}
185 
186 	*_reg = reg;
187 	*_shift = shift;
188 	*_mask = mask;
189 
190 	return 0;
191 }
192 
193 static int max8998_get_voltage_sel(struct regulator_dev *rdev)
194 {
195 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
196 	struct i2c_client *i2c = max8998->iodev->i2c;
197 	int reg, shift = 0, mask, ret;
198 	u8 val;
199 
200 	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
201 	if (ret)
202 		return ret;
203 
204 	ret = max8998_read_reg(i2c, reg, &val);
205 	if (ret)
206 		return ret;
207 
208 	val >>= shift;
209 	val &= mask;
210 
211 	return val;
212 }
213 
214 static int max8998_set_voltage_ldo_sel(struct regulator_dev *rdev,
215 				       unsigned selector)
216 {
217 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
218 	struct i2c_client *i2c = max8998->iodev->i2c;
219 	int reg, shift = 0, mask, ret;
220 
221 	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
222 	if (ret)
223 		return ret;
224 
225 	ret = max8998_update_reg(i2c, reg, selector<<shift, mask<<shift);
226 
227 	return ret;
228 }
229 
230 static inline void buck1_gpio_set(int gpio1, int gpio2, int v)
231 {
232 	gpio_set_value(gpio1, v & 0x1);
233 	gpio_set_value(gpio2, (v >> 1) & 0x1);
234 }
235 
236 static inline void buck2_gpio_set(int gpio, int v)
237 {
238 	gpio_set_value(gpio, v & 0x1);
239 }
240 
241 static int max8998_set_voltage_buck_sel(struct regulator_dev *rdev,
242 					unsigned selector)
243 {
244 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
245 	struct max8998_platform_data *pdata = max8998->iodev->pdata;
246 	struct i2c_client *i2c = max8998->iodev->i2c;
247 	int buck = rdev_get_id(rdev);
248 	int reg, shift = 0, mask, ret, j;
249 	static u8 buck1_last_val;
250 
251 	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
252 	if (ret)
253 		return ret;
254 
255 	switch (buck) {
256 	case MAX8998_BUCK1:
257 		dev_dbg(max8998->dev,
258 			"BUCK1, selector:%d, buck1_vol1:%d, buck1_vol2:%d\n"
259 			"buck1_vol3:%d, buck1_vol4:%d\n",
260 			selector, max8998->buck1_vol[0], max8998->buck1_vol[1],
261 			max8998->buck1_vol[2], max8998->buck1_vol[3]);
262 
263 		if (gpio_is_valid(pdata->buck1_set1) &&
264 		    gpio_is_valid(pdata->buck1_set2)) {
265 
266 			/* check if requested voltage */
267 			/* value is already defined */
268 			for (j = 0; j < ARRAY_SIZE(max8998->buck1_vol); j++) {
269 				if (max8998->buck1_vol[j] == selector) {
270 					max8998->buck1_idx = j;
271 					buck1_gpio_set(pdata->buck1_set1,
272 						       pdata->buck1_set2, j);
273 					goto buck1_exit;
274 				}
275 			}
276 
277 			if (pdata->buck_voltage_lock)
278 				return -EINVAL;
279 
280 			/* no predefine regulator found */
281 			max8998->buck1_idx = (buck1_last_val % 2) + 2;
282 			dev_dbg(max8998->dev, "max8998->buck1_idx:%d\n",
283 				max8998->buck1_idx);
284 			max8998->buck1_vol[max8998->buck1_idx] = selector;
285 			ret = max8998_get_voltage_register(rdev, &reg,
286 							   &shift,
287 							   &mask);
288 			ret = max8998_write_reg(i2c, reg, selector);
289 			buck1_gpio_set(pdata->buck1_set1,
290 				       pdata->buck1_set2, max8998->buck1_idx);
291 			buck1_last_val++;
292 buck1_exit:
293 			dev_dbg(max8998->dev, "%s: SET1:%d, SET2:%d\n",
294 				i2c->name, gpio_get_value(pdata->buck1_set1),
295 				gpio_get_value(pdata->buck1_set2));
296 			break;
297 		} else {
298 			ret = max8998_write_reg(i2c, reg, selector);
299 		}
300 		break;
301 
302 	case MAX8998_BUCK2:
303 		dev_dbg(max8998->dev,
304 			"BUCK2, selector:%d buck2_vol1:%d, buck2_vol2:%d\n",
305 			selector, max8998->buck2_vol[0], max8998->buck2_vol[1]);
306 		if (gpio_is_valid(pdata->buck2_set3)) {
307 
308 			/* check if requested voltage */
309 			/* value is already defined */
310 			for (j = 0; j < ARRAY_SIZE(max8998->buck2_vol); j++) {
311 				if (max8998->buck2_vol[j] == selector) {
312 					max8998->buck2_idx = j;
313 					buck2_gpio_set(pdata->buck2_set3, j);
314 					goto buck2_exit;
315 				}
316 			}
317 
318 			if (pdata->buck_voltage_lock)
319 				return -EINVAL;
320 
321 			max8998_get_voltage_register(rdev,
322 					&reg, &shift, &mask);
323 			ret = max8998_write_reg(i2c, reg, selector);
324 			max8998->buck2_vol[max8998->buck2_idx] = selector;
325 			buck2_gpio_set(pdata->buck2_set3, max8998->buck2_idx);
326 buck2_exit:
327 			dev_dbg(max8998->dev, "%s: SET3:%d\n", i2c->name,
328 				gpio_get_value(pdata->buck2_set3));
329 		} else {
330 			ret = max8998_write_reg(i2c, reg, selector);
331 		}
332 		break;
333 
334 	case MAX8998_BUCK3:
335 	case MAX8998_BUCK4:
336 		ret = max8998_update_reg(i2c, reg, selector<<shift,
337 					 mask<<shift);
338 		break;
339 	}
340 
341 	return ret;
342 }
343 
344 static int max8998_set_voltage_buck_time_sel(struct regulator_dev *rdev,
345 					     unsigned int old_selector,
346 					     unsigned int new_selector)
347 {
348 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
349 	struct i2c_client *i2c = max8998->iodev->i2c;
350 	int buck = rdev_get_id(rdev);
351 	u8 val = 0;
352 	int difference, ret;
353 
354 	if (buck < MAX8998_BUCK1 || buck > MAX8998_BUCK4)
355 		return -EINVAL;
356 
357 	/* Voltage stabilization */
358 	ret = max8998_read_reg(i2c, MAX8998_REG_ONOFF4, &val);
359 	if (ret)
360 		return ret;
361 
362 	/* lp3974 hasn't got ENRAMP bit - ramp is assumed as true */
363 	/* MAX8998 has ENRAMP bit implemented, so test it*/
364 	if (max8998->iodev->type == TYPE_MAX8998 && !(val & MAX8998_ENRAMP))
365 		return 0;
366 
367 	difference = (new_selector - old_selector) * rdev->desc->uV_step / 1000;
368 	if (difference > 0)
369 		return DIV_ROUND_UP(difference, (val & 0x0f) + 1);
370 
371 	return 0;
372 }
373 
374 static int max8998_set_current_limit(struct regulator_dev *rdev,
375 				     int min_uA, int max_uA)
376 {
377 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
378 	struct i2c_client *i2c = max8998->iodev->i2c;
379 	unsigned int n_currents = rdev->desc->n_current_limits;
380 	int i, sel = -1;
381 
382 	if (n_currents == 0)
383 		return -EINVAL;
384 
385 	if (rdev->desc->curr_table) {
386 		const unsigned int *curr_table = rdev->desc->curr_table;
387 		bool ascend = curr_table[n_currents - 1] > curr_table[0];
388 
389 		/* search for closest to maximum */
390 		if (ascend) {
391 			for (i = n_currents - 1; i >= 0; i--) {
392 				if (min_uA <= curr_table[i] &&
393 				    curr_table[i] <= max_uA) {
394 					sel = i;
395 					break;
396 				}
397 			}
398 		} else {
399 			for (i = 0; i < n_currents; i++) {
400 				if (min_uA <= curr_table[i] &&
401 				    curr_table[i] <= max_uA) {
402 					sel = i;
403 					break;
404 				}
405 			}
406 		}
407 	}
408 
409 	if (sel < 0)
410 		return -EINVAL;
411 
412 	sel <<= ffs(rdev->desc->csel_mask) - 1;
413 
414 	return max8998_update_reg(i2c, rdev->desc->csel_reg,
415 				  sel, rdev->desc->csel_mask);
416 }
417 
418 static int max8998_get_current_limit(struct regulator_dev *rdev)
419 {
420 	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
421 	struct i2c_client *i2c = max8998->iodev->i2c;
422 	u8 val;
423 	int ret;
424 
425 	ret = max8998_read_reg(i2c, rdev->desc->csel_reg, &val);
426 	if (ret != 0)
427 		return ret;
428 
429 	val &= rdev->desc->csel_mask;
430 	val >>= ffs(rdev->desc->csel_mask) - 1;
431 
432 	if (rdev->desc->curr_table) {
433 		if (val >= rdev->desc->n_current_limits)
434 			return -EINVAL;
435 
436 		return rdev->desc->curr_table[val];
437 	}
438 
439 	return -EINVAL;
440 }
441 
442 static const struct regulator_ops max8998_ldo_ops = {
443 	.list_voltage		= regulator_list_voltage_linear,
444 	.map_voltage		= regulator_map_voltage_linear,
445 	.is_enabled		= max8998_ldo_is_enabled,
446 	.enable			= max8998_ldo_enable,
447 	.disable		= max8998_ldo_disable,
448 	.get_voltage_sel	= max8998_get_voltage_sel,
449 	.set_voltage_sel	= max8998_set_voltage_ldo_sel,
450 };
451 
452 static const struct regulator_ops max8998_buck_ops = {
453 	.list_voltage		= regulator_list_voltage_linear,
454 	.map_voltage		= regulator_map_voltage_linear,
455 	.is_enabled		= max8998_ldo_is_enabled,
456 	.enable			= max8998_ldo_enable,
457 	.disable		= max8998_ldo_disable,
458 	.get_voltage_sel	= max8998_get_voltage_sel,
459 	.set_voltage_sel	= max8998_set_voltage_buck_sel,
460 	.set_voltage_time_sel	= max8998_set_voltage_buck_time_sel,
461 };
462 
463 static const struct regulator_ops max8998_charger_ops = {
464 	.set_current_limit	= max8998_set_current_limit,
465 	.get_current_limit	= max8998_get_current_limit,
466 	.is_enabled		= max8998_ldo_is_enabled_inverted,
467 	/* Swapped as register is inverted */
468 	.enable			= max8998_ldo_disable,
469 	.disable		= max8998_ldo_enable,
470 };
471 
472 static const struct regulator_ops max8998_others_ops = {
473 	.is_enabled		= max8998_ldo_is_enabled,
474 	.enable			= max8998_ldo_enable,
475 	.disable		= max8998_ldo_disable,
476 };
477 
478 #define MAX8998_LINEAR_REG(_name, _ops, _min, _step, _max) \
479 	{ \
480 		.name = #_name, \
481 		.id = MAX8998_##_name, \
482 		.ops = _ops, \
483 		.min_uV = (_min), \
484 		.uV_step = (_step), \
485 		.n_voltages = ((_max) - (_min)) / (_step) + 1, \
486 		.type = REGULATOR_VOLTAGE, \
487 		.owner = THIS_MODULE, \
488 	}
489 
490 #define MAX8998_CURRENT_REG(_name, _ops, _table, _reg, _mask) \
491 	{ \
492 		.name = #_name, \
493 		.id = MAX8998_##_name, \
494 		.ops = _ops, \
495 		.curr_table = _table, \
496 		.n_current_limits = ARRAY_SIZE(_table), \
497 		.csel_reg = _reg, \
498 		.csel_mask = _mask, \
499 		.type = REGULATOR_CURRENT, \
500 		.owner = THIS_MODULE, \
501 	}
502 
503 #define MAX8998_OTHERS_REG(_name, _id) \
504 	{ \
505 		.name = #_name, \
506 		.id = _id, \
507 		.ops = &max8998_others_ops, \
508 		.type = REGULATOR_VOLTAGE, \
509 		.owner = THIS_MODULE, \
510 	}
511 
512 static const struct regulator_desc regulators[] = {
513 	MAX8998_LINEAR_REG(LDO2, &max8998_ldo_ops, 800000, 50000, 1300000),
514 	MAX8998_LINEAR_REG(LDO3, &max8998_ldo_ops, 800000, 50000, 1300000),
515 	MAX8998_LINEAR_REG(LDO4, &max8998_ldo_ops, 1600000, 100000, 3600000),
516 	MAX8998_LINEAR_REG(LDO5, &max8998_ldo_ops, 1600000, 100000, 3600000),
517 	MAX8998_LINEAR_REG(LDO6, &max8998_ldo_ops, 1600000, 100000, 3600000),
518 	MAX8998_LINEAR_REG(LDO7, &max8998_ldo_ops, 1600000, 100000, 3600000),
519 	MAX8998_LINEAR_REG(LDO8, &max8998_ldo_ops, 3000000, 100000, 3600000),
520 	MAX8998_LINEAR_REG(LDO9, &max8998_ldo_ops, 2800000, 100000, 3100000),
521 	MAX8998_LINEAR_REG(LDO10, &max8998_ldo_ops, 950000, 50000, 1300000),
522 	MAX8998_LINEAR_REG(LDO11, &max8998_ldo_ops, 1600000, 100000, 3600000),
523 	MAX8998_LINEAR_REG(LDO12, &max8998_ldo_ops, 800000, 100000, 3300000),
524 	MAX8998_LINEAR_REG(LDO13, &max8998_ldo_ops, 800000, 100000, 3300000),
525 	MAX8998_LINEAR_REG(LDO14, &max8998_ldo_ops, 1200000, 100000, 3300000),
526 	MAX8998_LINEAR_REG(LDO15, &max8998_ldo_ops, 1200000, 100000, 3300000),
527 	MAX8998_LINEAR_REG(LDO16, &max8998_ldo_ops, 1600000, 100000, 3600000),
528 	MAX8998_LINEAR_REG(LDO17, &max8998_ldo_ops, 1600000, 100000, 3600000),
529 	MAX8998_LINEAR_REG(BUCK1, &max8998_buck_ops, 750000, 25000, 1525000),
530 	MAX8998_LINEAR_REG(BUCK2, &max8998_buck_ops, 750000, 25000, 1525000),
531 	MAX8998_LINEAR_REG(BUCK3, &max8998_buck_ops, 1600000, 100000, 3600000),
532 	MAX8998_LINEAR_REG(BUCK4, &max8998_buck_ops, 800000, 100000, 2300000),
533 	MAX8998_OTHERS_REG(EN32KHz-AP, MAX8998_EN32KHZ_AP),
534 	MAX8998_OTHERS_REG(EN32KHz-CP, MAX8998_EN32KHZ_CP),
535 	MAX8998_OTHERS_REG(ENVICHG, MAX8998_ENVICHG),
536 	MAX8998_OTHERS_REG(ESAFEOUT1, MAX8998_ESAFEOUT1),
537 	MAX8998_OTHERS_REG(ESAFEOUT2, MAX8998_ESAFEOUT2),
538 	MAX8998_CURRENT_REG(CHARGER, &max8998_charger_ops,
539 			    charger_current_table, MAX8998_REG_CHGR1, 0x7),
540 };
541 
542 static int max8998_pmic_dt_parse_dvs_gpio(struct max8998_dev *iodev,
543 			struct max8998_platform_data *pdata,
544 			struct device_node *pmic_np)
545 {
546 	int gpio;
547 
548 	gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck1-dvs-gpios", 0);
549 	if (!gpio_is_valid(gpio)) {
550 		dev_err(iodev->dev, "invalid buck1 gpio[0]: %d\n", gpio);
551 		return -EINVAL;
552 	}
553 	pdata->buck1_set1 = gpio;
554 
555 	gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck1-dvs-gpios", 1);
556 	if (!gpio_is_valid(gpio)) {
557 		dev_err(iodev->dev, "invalid buck1 gpio[1]: %d\n", gpio);
558 		return -EINVAL;
559 	}
560 	pdata->buck1_set2 = gpio;
561 
562 	gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck2-dvs-gpio", 0);
563 	if (!gpio_is_valid(gpio)) {
564 		dev_err(iodev->dev, "invalid buck 2 gpio: %d\n", gpio);
565 		return -EINVAL;
566 	}
567 	pdata->buck2_set3 = gpio;
568 
569 	return 0;
570 }
571 
572 static int max8998_pmic_dt_parse_pdata(struct max8998_dev *iodev,
573 					struct max8998_platform_data *pdata)
574 {
575 	struct device_node *pmic_np = iodev->dev->of_node;
576 	struct device_node *regulators_np, *reg_np;
577 	struct max8998_regulator_data *rdata;
578 	unsigned int i;
579 	int ret;
580 
581 	regulators_np = of_get_child_by_name(pmic_np, "regulators");
582 	if (!regulators_np) {
583 		dev_err(iodev->dev, "could not find regulators sub-node\n");
584 		return -EINVAL;
585 	}
586 
587 	/* count the number of regulators to be supported in pmic */
588 	pdata->num_regulators = of_get_child_count(regulators_np);
589 
590 	rdata = devm_kcalloc(iodev->dev,
591 			     pdata->num_regulators, sizeof(*rdata),
592 			     GFP_KERNEL);
593 	if (!rdata) {
594 		of_node_put(regulators_np);
595 		return -ENOMEM;
596 	}
597 
598 	pdata->regulators = rdata;
599 	for (i = 0; i < ARRAY_SIZE(regulators); ++i) {
600 		reg_np = of_get_child_by_name(regulators_np,
601 							regulators[i].name);
602 		if (!reg_np)
603 			continue;
604 
605 		rdata->id = regulators[i].id;
606 		rdata->initdata = of_get_regulator_init_data(iodev->dev,
607 							     reg_np,
608 							     &regulators[i]);
609 		rdata->reg_node = reg_np;
610 		++rdata;
611 	}
612 	pdata->num_regulators = rdata - pdata->regulators;
613 
614 	of_node_put(reg_np);
615 	of_node_put(regulators_np);
616 
617 	ret = max8998_pmic_dt_parse_dvs_gpio(iodev, pdata, pmic_np);
618 	if (ret)
619 		return -EINVAL;
620 
621 	pdata->buck_voltage_lock = of_property_read_bool(pmic_np, "max8998,pmic-buck-voltage-lock");
622 
623 	ret = of_property_read_u32(pmic_np,
624 					"max8998,pmic-buck1-default-dvs-idx",
625 					&pdata->buck1_default_idx);
626 	if (!ret && pdata->buck1_default_idx >= 4) {
627 		pdata->buck1_default_idx = 0;
628 		dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
629 	}
630 
631 	ret = of_property_read_u32(pmic_np,
632 					"max8998,pmic-buck2-default-dvs-idx",
633 					&pdata->buck2_default_idx);
634 	if (!ret && pdata->buck2_default_idx >= 2) {
635 		pdata->buck2_default_idx = 0;
636 		dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
637 	}
638 
639 	ret = of_property_read_u32_array(pmic_np,
640 					"max8998,pmic-buck1-dvs-voltage",
641 					pdata->buck1_voltage,
642 					ARRAY_SIZE(pdata->buck1_voltage));
643 	if (ret) {
644 		dev_err(iodev->dev, "buck1 voltages not specified\n");
645 		return -EINVAL;
646 	}
647 
648 	ret = of_property_read_u32_array(pmic_np,
649 					"max8998,pmic-buck2-dvs-voltage",
650 					pdata->buck2_voltage,
651 					ARRAY_SIZE(pdata->buck2_voltage));
652 	if (ret) {
653 		dev_err(iodev->dev, "buck2 voltages not specified\n");
654 		return -EINVAL;
655 	}
656 
657 	return 0;
658 }
659 
660 static int max8998_pmic_probe(struct platform_device *pdev)
661 {
662 	struct max8998_dev *iodev = dev_get_drvdata(pdev->dev.parent);
663 	struct max8998_platform_data *pdata = iodev->pdata;
664 	struct regulator_config config = { };
665 	struct regulator_dev *rdev;
666 	struct max8998_data *max8998;
667 	struct i2c_client *i2c;
668 	int i, ret;
669 	unsigned int v;
670 
671 	if (!pdata) {
672 		dev_err(pdev->dev.parent, "No platform init data supplied\n");
673 		return -ENODEV;
674 	}
675 
676 	if (IS_ENABLED(CONFIG_OF) && iodev->dev->of_node) {
677 		ret = max8998_pmic_dt_parse_pdata(iodev, pdata);
678 		if (ret)
679 			return ret;
680 	}
681 
682 	max8998 = devm_kzalloc(&pdev->dev, sizeof(struct max8998_data),
683 			       GFP_KERNEL);
684 	if (!max8998)
685 		return -ENOMEM;
686 
687 	max8998->dev = &pdev->dev;
688 	max8998->iodev = iodev;
689 	max8998->num_regulators = pdata->num_regulators;
690 	platform_set_drvdata(pdev, max8998);
691 	i2c = max8998->iodev->i2c;
692 
693 	max8998->buck1_idx = pdata->buck1_default_idx;
694 	max8998->buck2_idx = pdata->buck2_default_idx;
695 
696 	/* NOTE: */
697 	/* For unused GPIO NOT marked as -1 (thereof equal to 0)  WARN_ON */
698 	/* will be displayed */
699 
700 	/* Check if MAX8998 voltage selection GPIOs are defined */
701 	if (gpio_is_valid(pdata->buck1_set1) &&
702 	    gpio_is_valid(pdata->buck1_set2)) {
703 		/* Check if SET1 is not equal to 0 */
704 		if (!pdata->buck1_set1) {
705 			dev_err(&pdev->dev,
706 				"MAX8998 SET1 GPIO defined as 0 !\n");
707 			WARN_ON(!pdata->buck1_set1);
708 			return -EIO;
709 		}
710 		/* Check if SET2 is not equal to 0 */
711 		if (!pdata->buck1_set2) {
712 			dev_err(&pdev->dev,
713 				"MAX8998 SET2 GPIO defined as 0 !\n");
714 			WARN_ON(!pdata->buck1_set2);
715 			return -EIO;
716 		}
717 
718 		gpio_request(pdata->buck1_set1, "MAX8998 BUCK1_SET1");
719 		gpio_direction_output(pdata->buck1_set1,
720 				      max8998->buck1_idx & 0x1);
721 
722 
723 		gpio_request(pdata->buck1_set2, "MAX8998 BUCK1_SET2");
724 		gpio_direction_output(pdata->buck1_set2,
725 				      (max8998->buck1_idx >> 1) & 0x1);
726 
727 		/* Set predefined values for BUCK1 registers */
728 		for (v = 0; v < ARRAY_SIZE(pdata->buck1_voltage); ++v) {
729 			int index = MAX8998_BUCK1 - MAX8998_LDO2;
730 
731 			i = 0;
732 			while (regulators[index].min_uV +
733 			       regulators[index].uV_step * i
734 			       < pdata->buck1_voltage[v])
735 				i++;
736 
737 			max8998->buck1_vol[v] = i;
738 			ret = max8998_write_reg(i2c,
739 					MAX8998_REG_BUCK1_VOLTAGE1 + v, i);
740 			if (ret)
741 				return ret;
742 		}
743 	}
744 
745 	if (gpio_is_valid(pdata->buck2_set3)) {
746 		/* Check if SET3 is not equal to 0 */
747 		if (!pdata->buck2_set3) {
748 			dev_err(&pdev->dev,
749 				"MAX8998 SET3 GPIO defined as 0 !\n");
750 			WARN_ON(!pdata->buck2_set3);
751 			return -EIO;
752 		}
753 		gpio_request(pdata->buck2_set3, "MAX8998 BUCK2_SET3");
754 		gpio_direction_output(pdata->buck2_set3,
755 				      max8998->buck2_idx & 0x1);
756 
757 		/* Set predefined values for BUCK2 registers */
758 		for (v = 0; v < ARRAY_SIZE(pdata->buck2_voltage); ++v) {
759 			int index = MAX8998_BUCK2 - MAX8998_LDO2;
760 
761 			i = 0;
762 			while (regulators[index].min_uV +
763 			       regulators[index].uV_step * i
764 			       < pdata->buck2_voltage[v])
765 				i++;
766 
767 			max8998->buck2_vol[v] = i;
768 			ret = max8998_write_reg(i2c,
769 					MAX8998_REG_BUCK2_VOLTAGE1 + v, i);
770 			if (ret)
771 				return ret;
772 		}
773 	}
774 
775 	for (i = 0; i < pdata->num_regulators; i++) {
776 		int index = pdata->regulators[i].id - MAX8998_LDO2;
777 
778 		config.dev = max8998->dev;
779 		config.of_node = pdata->regulators[i].reg_node;
780 		config.init_data = pdata->regulators[i].initdata;
781 		config.driver_data = max8998;
782 
783 		rdev = devm_regulator_register(&pdev->dev, &regulators[index],
784 					       &config);
785 		if (IS_ERR(rdev)) {
786 			ret = PTR_ERR(rdev);
787 			dev_err(max8998->dev, "regulator %s init failed (%d)\n",
788 						regulators[index].name, ret);
789 			return ret;
790 		}
791 	}
792 
793 	return 0;
794 }
795 
796 static const struct platform_device_id max8998_pmic_id[] = {
797 	{ "max8998-pmic", TYPE_MAX8998 },
798 	{ "lp3974-pmic", TYPE_LP3974 },
799 	{ }
800 };
801 MODULE_DEVICE_TABLE(platform, max8998_pmic_id);
802 
803 static struct platform_driver max8998_pmic_driver = {
804 	.driver = {
805 		.name = "max8998-pmic",
806 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
807 	},
808 	.probe = max8998_pmic_probe,
809 	.id_table = max8998_pmic_id,
810 };
811 
812 static int __init max8998_pmic_init(void)
813 {
814 	return platform_driver_register(&max8998_pmic_driver);
815 }
816 subsys_initcall(max8998_pmic_init);
817 
818 static void __exit max8998_pmic_cleanup(void)
819 {
820 	platform_driver_unregister(&max8998_pmic_driver);
821 }
822 module_exit(max8998_pmic_cleanup);
823 
824 MODULE_DESCRIPTION("MAXIM 8998 voltage regulator driver");
825 MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
826 MODULE_LICENSE("GPL");
827