xref: /linux/drivers/regulator/max77686-regulator.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // max77686.c - Regulator driver for the Maxim 77686
4 //
5 // Copyright (C) 2012 Samsung Electronics
6 // Chiwoong Byun <woong.byun@samsung.com>
7 // Jonghwa Lee <jonghwa3.lee@samsung.com>
8 //
9 // This driver is based on max8997.c
10 
11 #include <linux/kernel.h>
12 #include <linux/bug.h>
13 #include <linux/err.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/slab.h>
16 #include <linux/platform_device.h>
17 #include <linux/regulator/driver.h>
18 #include <linux/regulator/machine.h>
19 #include <linux/regulator/of_regulator.h>
20 #include <linux/mfd/max77686.h>
21 #include <linux/mfd/max77686-private.h>
22 
23 #define MAX77686_LDO_MINUV	800000
24 #define MAX77686_LDO_UVSTEP	50000
25 #define MAX77686_LDO_LOW_MINUV	800000
26 #define MAX77686_LDO_LOW_UVSTEP	25000
27 #define MAX77686_BUCK_MINUV	750000
28 #define MAX77686_BUCK_UVSTEP	50000
29 #define MAX77686_BUCK_ENABLE_TIME	40		/* us */
30 #define MAX77686_DVS_ENABLE_TIME	22		/* us */
31 #define MAX77686_RAMP_DELAY	100000			/* uV/us */
32 #define MAX77686_DVS_RAMP_DELAY	27500			/* uV/us */
33 #define MAX77686_DVS_MINUV	600000
34 #define MAX77686_DVS_UVSTEP	12500
35 
36 /*
37  * Value for configuring buck[89] and LDO{20,21,22} as GPIO control.
38  * It is the same as 'off' for other regulators.
39  */
40 #define MAX77686_GPIO_CONTROL		0x0
41 /*
42  * Values used for configuring LDOs and bucks.
43  * Forcing low power mode: LDO1, 3-5, 9, 13, 17-26
44  */
45 #define MAX77686_LDO_LOWPOWER		0x1
46 /*
47  * On/off controlled by PWRREQ:
48  *  - LDO2, 6-8, 10-12, 14-16
49  *  - buck[1234]
50  */
51 #define MAX77686_OFF_PWRREQ		0x1
52 /* Low power mode controlled by PWRREQ: All LDOs */
53 #define MAX77686_LDO_LOWPOWER_PWRREQ	0x2
54 /* Forcing low power mode: buck[234] */
55 #define MAX77686_BUCK_LOWPOWER		0x2
56 #define MAX77686_NORMAL			0x3
57 
58 #define MAX77686_OPMODE_SHIFT	6
59 #define MAX77686_OPMODE_BUCK234_SHIFT	4
60 #define MAX77686_OPMODE_MASK	0x3
61 
62 #define MAX77686_VSEL_MASK	0x3F
63 #define MAX77686_DVS_VSEL_MASK	0xFF
64 
65 #define MAX77686_RAMP_RATE_MASK	0xC0
66 
67 #define MAX77686_REGULATORS	MAX77686_REG_MAX
68 #define MAX77686_LDOS		26
69 
70 struct max77686_data {
71 	struct device *dev;
72 	DECLARE_BITMAP(gpio_enabled, MAX77686_REGULATORS);
73 
74 	/* Array indexed by regulator id */
75 	unsigned int opmode[MAX77686_REGULATORS];
76 };
77 
78 static unsigned int max77686_get_opmode_shift(int id)
79 {
80 	switch (id) {
81 	case MAX77686_BUCK1:
82 	case MAX77686_BUCK5 ... MAX77686_BUCK9:
83 		return 0;
84 	case MAX77686_BUCK2 ... MAX77686_BUCK4:
85 		return MAX77686_OPMODE_BUCK234_SHIFT;
86 	default:
87 		/* all LDOs */
88 		return MAX77686_OPMODE_SHIFT;
89 	}
90 }
91 
92 /*
93  * When regulator is configured for GPIO control then it
94  * replaces "normal" mode. Any change from low power mode to normal
95  * should actually change to GPIO control.
96  * Map normal mode to proper value for such regulators.
97  */
98 static unsigned int max77686_map_normal_mode(struct max77686_data *max77686,
99 					     int id)
100 {
101 	switch (id) {
102 	case MAX77686_BUCK8:
103 	case MAX77686_BUCK9:
104 	case MAX77686_LDO20 ... MAX77686_LDO22:
105 		if (test_bit(id, max77686->gpio_enabled))
106 			return MAX77686_GPIO_CONTROL;
107 	}
108 
109 	return MAX77686_NORMAL;
110 }
111 
112 /* Some BUCKs and LDOs supports Normal[ON/OFF] mode during suspend */
113 static int max77686_set_suspend_disable(struct regulator_dev *rdev)
114 {
115 	unsigned int val, shift;
116 	struct max77686_data *max77686 = rdev_get_drvdata(rdev);
117 	int ret, id = rdev_get_id(rdev);
118 
119 	shift = max77686_get_opmode_shift(id);
120 	val = MAX77686_OFF_PWRREQ;
121 
122 	ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
123 				 rdev->desc->enable_mask, val << shift);
124 	if (ret)
125 		return ret;
126 
127 	max77686->opmode[id] = val;
128 	return 0;
129 }
130 
131 /* Some LDOs supports [LPM/Normal]ON mode during suspend state */
132 static int max77686_set_suspend_mode(struct regulator_dev *rdev,
133 				     unsigned int mode)
134 {
135 	struct max77686_data *max77686 = rdev_get_drvdata(rdev);
136 	unsigned int val;
137 	int ret, id = rdev_get_id(rdev);
138 
139 	/* BUCK[5-9] doesn't support this feature */
140 	if (id >= MAX77686_BUCK5)
141 		return 0;
142 
143 	switch (mode) {
144 	case REGULATOR_MODE_IDLE:			/* ON in LP Mode */
145 		val = MAX77686_LDO_LOWPOWER_PWRREQ;
146 		break;
147 	case REGULATOR_MODE_NORMAL:			/* ON in Normal Mode */
148 		val = max77686_map_normal_mode(max77686, id);
149 		break;
150 	default:
151 		pr_warn("%s: regulator_suspend_mode : 0x%x not supported\n",
152 			rdev->desc->name, mode);
153 		return -EINVAL;
154 	}
155 
156 	ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
157 				  rdev->desc->enable_mask,
158 				  val << MAX77686_OPMODE_SHIFT);
159 	if (ret)
160 		return ret;
161 
162 	max77686->opmode[id] = val;
163 	return 0;
164 }
165 
166 /* Some LDOs supports LPM-ON/OFF/Normal-ON mode during suspend state */
167 static int max77686_ldo_set_suspend_mode(struct regulator_dev *rdev,
168 				     unsigned int mode)
169 {
170 	unsigned int val;
171 	struct max77686_data *max77686 = rdev_get_drvdata(rdev);
172 	int ret, id = rdev_get_id(rdev);
173 
174 	switch (mode) {
175 	case REGULATOR_MODE_STANDBY:			/* switch off */
176 		val = MAX77686_OFF_PWRREQ;
177 		break;
178 	case REGULATOR_MODE_IDLE:			/* ON in LP Mode */
179 		val = MAX77686_LDO_LOWPOWER_PWRREQ;
180 		break;
181 	case REGULATOR_MODE_NORMAL:			/* ON in Normal Mode */
182 		val = max77686_map_normal_mode(max77686, id);
183 		break;
184 	default:
185 		pr_warn("%s: regulator_suspend_mode : 0x%x not supported\n",
186 			rdev->desc->name, mode);
187 		return -EINVAL;
188 	}
189 
190 	ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
191 				 rdev->desc->enable_mask,
192 				 val << MAX77686_OPMODE_SHIFT);
193 	if (ret)
194 		return ret;
195 
196 	max77686->opmode[id] = val;
197 	return 0;
198 }
199 
200 static int max77686_enable(struct regulator_dev *rdev)
201 {
202 	struct max77686_data *max77686 = rdev_get_drvdata(rdev);
203 	unsigned int shift;
204 	int id = rdev_get_id(rdev);
205 
206 	shift = max77686_get_opmode_shift(id);
207 
208 	if (max77686->opmode[id] == MAX77686_OFF_PWRREQ)
209 		max77686->opmode[id] = max77686_map_normal_mode(max77686, id);
210 
211 	return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
212 				  rdev->desc->enable_mask,
213 				  max77686->opmode[id] << shift);
214 }
215 
216 static int max77686_of_parse_cb(struct device_node *np,
217 		const struct regulator_desc *desc,
218 		struct regulator_config *config)
219 {
220 	struct max77686_data *max77686 = config->driver_data;
221 	int ret;
222 
223 	switch (desc->id) {
224 	case MAX77686_BUCK8:
225 	case MAX77686_BUCK9:
226 	case MAX77686_LDO20 ... MAX77686_LDO22:
227 		config->ena_gpiod = fwnode_gpiod_get_index(
228 				of_fwnode_handle(np),
229 				"maxim,ena",
230 				0,
231 				GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE,
232 				"max77686-regulator");
233 		if (IS_ERR(config->ena_gpiod))
234 			config->ena_gpiod = NULL;
235 		break;
236 	default:
237 		return 0;
238 	}
239 
240 	if (config->ena_gpiod) {
241 		set_bit(desc->id, max77686->gpio_enabled);
242 
243 		ret = regmap_update_bits(config->regmap, desc->enable_reg,
244 					 desc->enable_mask,
245 					 MAX77686_GPIO_CONTROL);
246 		if (ret) {
247 			gpiod_put(config->ena_gpiod);
248 			config->ena_gpiod = NULL;
249 		}
250 	}
251 
252 	return 0;
253 }
254 
255 static const unsigned int max77686_buck_dvs_ramp_table[] = {
256 	13750, 27500, 55000, 100000
257 };
258 
259 static const struct regulator_ops max77686_ops = {
260 	.list_voltage		= regulator_list_voltage_linear,
261 	.map_voltage		= regulator_map_voltage_linear,
262 	.is_enabled		= regulator_is_enabled_regmap,
263 	.enable			= max77686_enable,
264 	.disable		= regulator_disable_regmap,
265 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
266 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
267 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
268 	.set_suspend_mode	= max77686_set_suspend_mode,
269 };
270 
271 static const struct regulator_ops max77686_ldo_ops = {
272 	.list_voltage		= regulator_list_voltage_linear,
273 	.map_voltage		= regulator_map_voltage_linear,
274 	.is_enabled		= regulator_is_enabled_regmap,
275 	.enable			= max77686_enable,
276 	.disable		= regulator_disable_regmap,
277 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
278 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
279 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
280 	.set_suspend_mode	= max77686_ldo_set_suspend_mode,
281 	.set_suspend_disable	= max77686_set_suspend_disable,
282 };
283 
284 static const struct regulator_ops max77686_buck1_ops = {
285 	.list_voltage		= regulator_list_voltage_linear,
286 	.map_voltage		= regulator_map_voltage_linear,
287 	.is_enabled		= regulator_is_enabled_regmap,
288 	.enable			= max77686_enable,
289 	.disable		= regulator_disable_regmap,
290 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
291 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
292 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
293 	.set_suspend_disable	= max77686_set_suspend_disable,
294 };
295 
296 static const struct regulator_ops max77686_buck_dvs_ops = {
297 	.list_voltage		= regulator_list_voltage_linear,
298 	.map_voltage		= regulator_map_voltage_linear,
299 	.is_enabled		= regulator_is_enabled_regmap,
300 	.enable			= max77686_enable,
301 	.disable		= regulator_disable_regmap,
302 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
303 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
304 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
305 	.set_ramp_delay		= regulator_set_ramp_delay_regmap,
306 	.set_suspend_disable	= max77686_set_suspend_disable,
307 };
308 
309 #define regulator_desc_ldo(num)		{				\
310 	.name		= "LDO"#num,					\
311 	.of_match	= of_match_ptr("LDO"#num),			\
312 	.regulators_node	= of_match_ptr("voltage-regulators"),	\
313 	.of_parse_cb	= max77686_of_parse_cb,				\
314 	.id		= MAX77686_LDO##num,				\
315 	.ops		= &max77686_ops,				\
316 	.type		= REGULATOR_VOLTAGE,				\
317 	.owner		= THIS_MODULE,					\
318 	.min_uV		= MAX77686_LDO_MINUV,				\
319 	.uV_step	= MAX77686_LDO_UVSTEP,				\
320 	.ramp_delay	= MAX77686_RAMP_DELAY,				\
321 	.n_voltages	= MAX77686_VSEL_MASK + 1,			\
322 	.vsel_reg	= MAX77686_REG_LDO1CTRL1 + num - 1,		\
323 	.vsel_mask	= MAX77686_VSEL_MASK,				\
324 	.enable_reg	= MAX77686_REG_LDO1CTRL1 + num - 1,		\
325 	.enable_mask	= MAX77686_OPMODE_MASK				\
326 			<< MAX77686_OPMODE_SHIFT,			\
327 }
328 #define regulator_desc_lpm_ldo(num)	{				\
329 	.name		= "LDO"#num,					\
330 	.of_match	= of_match_ptr("LDO"#num),			\
331 	.regulators_node	= of_match_ptr("voltage-regulators"),	\
332 	.id		= MAX77686_LDO##num,				\
333 	.ops		= &max77686_ldo_ops,				\
334 	.type		= REGULATOR_VOLTAGE,				\
335 	.owner		= THIS_MODULE,					\
336 	.min_uV		= MAX77686_LDO_MINUV,				\
337 	.uV_step	= MAX77686_LDO_UVSTEP,				\
338 	.ramp_delay	= MAX77686_RAMP_DELAY,				\
339 	.n_voltages	= MAX77686_VSEL_MASK + 1,			\
340 	.vsel_reg	= MAX77686_REG_LDO1CTRL1 + num - 1,		\
341 	.vsel_mask	= MAX77686_VSEL_MASK,				\
342 	.enable_reg	= MAX77686_REG_LDO1CTRL1 + num - 1,		\
343 	.enable_mask	= MAX77686_OPMODE_MASK				\
344 			<< MAX77686_OPMODE_SHIFT,			\
345 }
346 #define regulator_desc_ldo_low(num)		{			\
347 	.name		= "LDO"#num,					\
348 	.of_match	= of_match_ptr("LDO"#num),			\
349 	.regulators_node	= of_match_ptr("voltage-regulators"),	\
350 	.id		= MAX77686_LDO##num,				\
351 	.ops		= &max77686_ldo_ops,				\
352 	.type		= REGULATOR_VOLTAGE,				\
353 	.owner		= THIS_MODULE,					\
354 	.min_uV		= MAX77686_LDO_LOW_MINUV,			\
355 	.uV_step	= MAX77686_LDO_LOW_UVSTEP,			\
356 	.ramp_delay	= MAX77686_RAMP_DELAY,				\
357 	.n_voltages	= MAX77686_VSEL_MASK + 1,			\
358 	.vsel_reg	= MAX77686_REG_LDO1CTRL1 + num - 1,		\
359 	.vsel_mask	= MAX77686_VSEL_MASK,				\
360 	.enable_reg	= MAX77686_REG_LDO1CTRL1 + num - 1,		\
361 	.enable_mask	= MAX77686_OPMODE_MASK				\
362 			<< MAX77686_OPMODE_SHIFT,			\
363 }
364 #define regulator_desc_ldo1_low(num)		{			\
365 	.name		= "LDO"#num,					\
366 	.of_match	= of_match_ptr("LDO"#num),			\
367 	.regulators_node	= of_match_ptr("voltage-regulators"),	\
368 	.id		= MAX77686_LDO##num,				\
369 	.ops		= &max77686_ops,				\
370 	.type		= REGULATOR_VOLTAGE,				\
371 	.owner		= THIS_MODULE,					\
372 	.min_uV		= MAX77686_LDO_LOW_MINUV,			\
373 	.uV_step	= MAX77686_LDO_LOW_UVSTEP,			\
374 	.ramp_delay	= MAX77686_RAMP_DELAY,				\
375 	.n_voltages	= MAX77686_VSEL_MASK + 1,			\
376 	.vsel_reg	= MAX77686_REG_LDO1CTRL1 + num - 1,		\
377 	.vsel_mask	= MAX77686_VSEL_MASK,				\
378 	.enable_reg	= MAX77686_REG_LDO1CTRL1 + num - 1,		\
379 	.enable_mask	= MAX77686_OPMODE_MASK				\
380 			<< MAX77686_OPMODE_SHIFT,			\
381 }
382 #define regulator_desc_buck(num)		{			\
383 	.name		= "BUCK"#num,					\
384 	.of_match	= of_match_ptr("BUCK"#num),			\
385 	.regulators_node	= of_match_ptr("voltage-regulators"),	\
386 	.of_parse_cb	= max77686_of_parse_cb,				\
387 	.id		= MAX77686_BUCK##num,				\
388 	.ops		= &max77686_ops,				\
389 	.type		= REGULATOR_VOLTAGE,				\
390 	.owner		= THIS_MODULE,					\
391 	.min_uV		= MAX77686_BUCK_MINUV,				\
392 	.uV_step	= MAX77686_BUCK_UVSTEP,				\
393 	.ramp_delay	= MAX77686_RAMP_DELAY,				\
394 	.enable_time	= MAX77686_BUCK_ENABLE_TIME,			\
395 	.n_voltages	= MAX77686_VSEL_MASK + 1,			\
396 	.vsel_reg	= MAX77686_REG_BUCK5OUT + (num - 5) * 2,	\
397 	.vsel_mask	= MAX77686_VSEL_MASK,				\
398 	.enable_reg	= MAX77686_REG_BUCK5CTRL + (num - 5) * 2,	\
399 	.enable_mask	= MAX77686_OPMODE_MASK,				\
400 }
401 #define regulator_desc_buck1(num)		{			\
402 	.name		= "BUCK"#num,					\
403 	.of_match	= of_match_ptr("BUCK"#num),			\
404 	.regulators_node	= of_match_ptr("voltage-regulators"),	\
405 	.id		= MAX77686_BUCK##num,				\
406 	.ops		= &max77686_buck1_ops,				\
407 	.type		= REGULATOR_VOLTAGE,				\
408 	.owner		= THIS_MODULE,					\
409 	.min_uV		= MAX77686_BUCK_MINUV,				\
410 	.uV_step	= MAX77686_BUCK_UVSTEP,				\
411 	.ramp_delay	= MAX77686_RAMP_DELAY,				\
412 	.enable_time	= MAX77686_BUCK_ENABLE_TIME,			\
413 	.n_voltages	= MAX77686_VSEL_MASK + 1,			\
414 	.vsel_reg	= MAX77686_REG_BUCK1OUT,			\
415 	.vsel_mask	= MAX77686_VSEL_MASK,				\
416 	.enable_reg	= MAX77686_REG_BUCK1CTRL,			\
417 	.enable_mask	= MAX77686_OPMODE_MASK,				\
418 }
419 #define regulator_desc_buck_dvs(num)		{			\
420 	.name		= "BUCK"#num,					\
421 	.of_match	= of_match_ptr("BUCK"#num),			\
422 	.regulators_node	= of_match_ptr("voltage-regulators"),	\
423 	.id		= MAX77686_BUCK##num,				\
424 	.ops		= &max77686_buck_dvs_ops,			\
425 	.type		= REGULATOR_VOLTAGE,				\
426 	.owner		= THIS_MODULE,					\
427 	.min_uV		= MAX77686_DVS_MINUV,				\
428 	.uV_step	= MAX77686_DVS_UVSTEP,				\
429 	.ramp_delay	= MAX77686_DVS_RAMP_DELAY,			\
430 	.enable_time	= MAX77686_DVS_ENABLE_TIME,			\
431 	.n_voltages	= MAX77686_DVS_VSEL_MASK + 1,			\
432 	.vsel_reg	= MAX77686_REG_BUCK2DVS1 + (num - 2) * 10,	\
433 	.vsel_mask	= MAX77686_DVS_VSEL_MASK,			\
434 	.enable_reg	= MAX77686_REG_BUCK2CTRL1 + (num - 2) * 10,	\
435 	.enable_mask	= MAX77686_OPMODE_MASK				\
436 			<< MAX77686_OPMODE_BUCK234_SHIFT,		\
437 	.ramp_reg	= MAX77686_REG_BUCK2CTRL1 + (num - 2) * 10,	\
438 	.ramp_mask	= MAX77686_RAMP_RATE_MASK,			\
439 	.ramp_delay_table = max77686_buck_dvs_ramp_table,		\
440 	.n_ramp_values	= ARRAY_SIZE(max77686_buck_dvs_ramp_table),	\
441 }
442 
443 static const struct regulator_desc regulators[] = {
444 	regulator_desc_ldo1_low(1),
445 	regulator_desc_ldo_low(2),
446 	regulator_desc_ldo(3),
447 	regulator_desc_ldo(4),
448 	regulator_desc_ldo(5),
449 	regulator_desc_ldo_low(6),
450 	regulator_desc_ldo_low(7),
451 	regulator_desc_ldo_low(8),
452 	regulator_desc_ldo(9),
453 	regulator_desc_lpm_ldo(10),
454 	regulator_desc_lpm_ldo(11),
455 	regulator_desc_lpm_ldo(12),
456 	regulator_desc_ldo(13),
457 	regulator_desc_lpm_ldo(14),
458 	regulator_desc_ldo_low(15),
459 	regulator_desc_lpm_ldo(16),
460 	regulator_desc_ldo(17),
461 	regulator_desc_ldo(18),
462 	regulator_desc_ldo(19),
463 	regulator_desc_ldo(20),
464 	regulator_desc_ldo(21),
465 	regulator_desc_ldo(22),
466 	regulator_desc_ldo(23),
467 	regulator_desc_ldo(24),
468 	regulator_desc_ldo(25),
469 	regulator_desc_ldo(26),
470 	regulator_desc_buck1(1),
471 	regulator_desc_buck_dvs(2),
472 	regulator_desc_buck_dvs(3),
473 	regulator_desc_buck_dvs(4),
474 	regulator_desc_buck(5),
475 	regulator_desc_buck(6),
476 	regulator_desc_buck(7),
477 	regulator_desc_buck(8),
478 	regulator_desc_buck(9),
479 };
480 
481 static int max77686_pmic_probe(struct platform_device *pdev)
482 {
483 	struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
484 	struct max77686_data *max77686;
485 	int i;
486 	struct regulator_config config = { };
487 
488 	dev_dbg(&pdev->dev, "%s\n", __func__);
489 
490 	max77686 = devm_kzalloc(&pdev->dev, sizeof(struct max77686_data),
491 				GFP_KERNEL);
492 	if (!max77686)
493 		return -ENOMEM;
494 
495 	max77686->dev = &pdev->dev;
496 	config.dev = iodev->dev;
497 	config.regmap = iodev->regmap;
498 	config.driver_data = max77686;
499 	platform_set_drvdata(pdev, max77686);
500 
501 	for (i = 0; i < MAX77686_REGULATORS; i++) {
502 		struct regulator_dev *rdev;
503 		int id = regulators[i].id;
504 
505 		max77686->opmode[id] = MAX77686_NORMAL;
506 		rdev = devm_regulator_register(&pdev->dev,
507 						&regulators[i], &config);
508 		if (IS_ERR(rdev)) {
509 			int ret = PTR_ERR(rdev);
510 			dev_err(&pdev->dev,
511 				"regulator init failed for %d: %d\n", i, ret);
512 			return ret;
513 		}
514 	}
515 
516 	return 0;
517 }
518 
519 static const struct platform_device_id max77686_pmic_id[] = {
520 	{"max77686-pmic", 0},
521 	{ },
522 };
523 MODULE_DEVICE_TABLE(platform, max77686_pmic_id);
524 
525 static struct platform_driver max77686_pmic_driver = {
526 	.driver = {
527 		.name = "max77686-pmic",
528 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
529 	},
530 	.probe = max77686_pmic_probe,
531 	.id_table = max77686_pmic_id,
532 };
533 
534 module_platform_driver(max77686_pmic_driver);
535 
536 MODULE_DESCRIPTION("MAXIM 77686 Regulator Driver");
537 MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
538 MODULE_LICENSE("GPL");
539