1 /*
2  * Regulator driver for National Semiconductors LP3971 PMIC chip
3  *
4  *  Copyright (C) 2009 Samsung Electronics
5  *  Author: Marek Szyprowski <m.szyprowski@samsung.com>
6  *
7  * Based on wm8350.c
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  */
14 
15 #include <linux/bug.h>
16 #include <linux/err.h>
17 #include <linux/i2c.h>
18 #include <linux/kernel.h>
19 #include <linux/regulator/driver.h>
20 #include <linux/regulator/lp3971.h>
21 #include <linux/slab.h>
22 
23 struct lp3971 {
24 	struct device *dev;
25 	struct mutex io_lock;
26 	struct i2c_client *i2c;
27 	int num_regulators;
28 	struct regulator_dev **rdev;
29 };
30 
31 static u8 lp3971_reg_read(struct lp3971 *lp3971, u8 reg);
32 static int lp3971_set_bits(struct lp3971 *lp3971, u8 reg, u16 mask, u16 val);
33 
34 #define LP3971_SYS_CONTROL1_REG 0x07
35 
36 /* System control register 1 initial value,
37    bits 4 and 5 are EPROM programmable */
38 #define SYS_CONTROL1_INIT_VAL 0x40
39 #define SYS_CONTROL1_INIT_MASK 0xCF
40 
41 #define LP3971_BUCK_VOL_ENABLE_REG 0x10
42 #define LP3971_BUCK_VOL_CHANGE_REG 0x20
43 
44 /*	Voltage control registers shift:
45 	LP3971_BUCK1 -> 0
46 	LP3971_BUCK2 -> 4
47 	LP3971_BUCK3 -> 6
48 */
49 #define BUCK_VOL_CHANGE_SHIFT(x) (((!!x) << 2) | (x & ~0x01))
50 #define BUCK_VOL_CHANGE_FLAG_GO 0x01
51 #define BUCK_VOL_CHANGE_FLAG_TARGET 0x02
52 #define BUCK_VOL_CHANGE_FLAG_MASK 0x03
53 
54 #define LP3971_BUCK1_BASE 0x23
55 #define LP3971_BUCK2_BASE 0x29
56 #define LP3971_BUCK3_BASE 0x32
57 
58 static const int buck_base_addr[] = {
59 	LP3971_BUCK1_BASE,
60 	LP3971_BUCK2_BASE,
61 	LP3971_BUCK3_BASE,
62 };
63 
64 #define LP3971_BUCK_TARGET_VOL1_REG(x) (buck_base_addr[x])
65 #define LP3971_BUCK_TARGET_VOL2_REG(x) (buck_base_addr[x]+1)
66 
67 static const int buck_voltage_map[] = {
68 	   0,  800,  850,  900,  950, 1000, 1050, 1100,
69 	1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500,
70 	1550, 1600, 1650, 1700, 1800, 1900, 2500, 2800,
71 	3000, 3300,
72 };
73 
74 #define BUCK_TARGET_VOL_MASK 0x3f
75 #define BUCK_TARGET_VOL_MIN_IDX 0x01
76 #define BUCK_TARGET_VOL_MAX_IDX 0x19
77 
78 #define LP3971_BUCK_RAMP_REG(x)	(buck_base_addr[x]+2)
79 
80 #define LP3971_LDO_ENABLE_REG 0x12
81 #define LP3971_LDO_VOL_CONTR_BASE 0x39
82 
83 /*	Voltage control registers:
84 	LP3971_LDO1 -> LP3971_LDO_VOL_CONTR_BASE + 0
85 	LP3971_LDO2 -> LP3971_LDO_VOL_CONTR_BASE + 0
86 	LP3971_LDO3 -> LP3971_LDO_VOL_CONTR_BASE + 1
87 	LP3971_LDO4 -> LP3971_LDO_VOL_CONTR_BASE + 1
88 	LP3971_LDO5 -> LP3971_LDO_VOL_CONTR_BASE + 2
89 */
90 #define LP3971_LDO_VOL_CONTR_REG(x)	(LP3971_LDO_VOL_CONTR_BASE + (x >> 1))
91 
92 /*	Voltage control registers shift:
93 	LP3971_LDO1 -> 0, LP3971_LDO2 -> 4
94 	LP3971_LDO3 -> 0, LP3971_LDO4 -> 4
95 	LP3971_LDO5 -> 0
96 */
97 #define LDO_VOL_CONTR_SHIFT(x) ((x & 1) << 2)
98 #define LDO_VOL_CONTR_MASK 0x0f
99 
100 static const int ldo45_voltage_map[] = {
101 	1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350,
102 	1400, 1500, 1800, 1900, 2500, 2800, 3000, 3300,
103 };
104 
105 static const int ldo123_voltage_map[] = {
106 	1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500,
107 	2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300,
108 };
109 
110 static const int *ldo_voltage_map[] = {
111 	ldo123_voltage_map, /* LDO1 */
112 	ldo123_voltage_map, /* LDO2 */
113 	ldo123_voltage_map, /* LDO3 */
114 	ldo45_voltage_map, /* LDO4 */
115 	ldo45_voltage_map, /* LDO5 */
116 };
117 
118 #define LDO_VOL_VALUE_MAP(x) (ldo_voltage_map[(x - LP3971_LDO1)])
119 
120 #define LDO_VOL_MIN_IDX 0x00
121 #define LDO_VOL_MAX_IDX 0x0f
122 
lp3971_ldo_list_voltage(struct regulator_dev * dev,unsigned index)123 static int lp3971_ldo_list_voltage(struct regulator_dev *dev, unsigned index)
124 {
125 	int ldo = rdev_get_id(dev) - LP3971_LDO1;
126 	return 1000 * LDO_VOL_VALUE_MAP(ldo)[index];
127 }
128 
lp3971_ldo_is_enabled(struct regulator_dev * dev)129 static int lp3971_ldo_is_enabled(struct regulator_dev *dev)
130 {
131 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
132 	int ldo = rdev_get_id(dev) - LP3971_LDO1;
133 	u16 mask = 1 << (1 + ldo);
134 	u16 val;
135 
136 	val = lp3971_reg_read(lp3971, LP3971_LDO_ENABLE_REG);
137 	return (val & mask) != 0;
138 }
139 
lp3971_ldo_enable(struct regulator_dev * dev)140 static int lp3971_ldo_enable(struct regulator_dev *dev)
141 {
142 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
143 	int ldo = rdev_get_id(dev) - LP3971_LDO1;
144 	u16 mask = 1 << (1 + ldo);
145 
146 	return lp3971_set_bits(lp3971, LP3971_LDO_ENABLE_REG, mask, mask);
147 }
148 
lp3971_ldo_disable(struct regulator_dev * dev)149 static int lp3971_ldo_disable(struct regulator_dev *dev)
150 {
151 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
152 	int ldo = rdev_get_id(dev) - LP3971_LDO1;
153 	u16 mask = 1 << (1 + ldo);
154 
155 	return lp3971_set_bits(lp3971, LP3971_LDO_ENABLE_REG, mask, 0);
156 }
157 
lp3971_ldo_get_voltage(struct regulator_dev * dev)158 static int lp3971_ldo_get_voltage(struct regulator_dev *dev)
159 {
160 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
161 	int ldo = rdev_get_id(dev) - LP3971_LDO1;
162 	u16 val, reg;
163 
164 	reg = lp3971_reg_read(lp3971, LP3971_LDO_VOL_CONTR_REG(ldo));
165 	val = (reg >> LDO_VOL_CONTR_SHIFT(ldo)) & LDO_VOL_CONTR_MASK;
166 
167 	return 1000 * LDO_VOL_VALUE_MAP(ldo)[val];
168 }
169 
lp3971_ldo_set_voltage(struct regulator_dev * dev,int min_uV,int max_uV,unsigned int * selector)170 static int lp3971_ldo_set_voltage(struct regulator_dev *dev,
171 				  int min_uV, int max_uV,
172 				  unsigned int *selector)
173 {
174 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
175 	int ldo = rdev_get_id(dev) - LP3971_LDO1;
176 	int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
177 	const int *vol_map = LDO_VOL_VALUE_MAP(ldo);
178 	u16 val;
179 
180 	if (min_vol < vol_map[LDO_VOL_MIN_IDX] ||
181 	    min_vol > vol_map[LDO_VOL_MAX_IDX])
182 		return -EINVAL;
183 
184 	for (val = LDO_VOL_MIN_IDX; val <= LDO_VOL_MAX_IDX; val++)
185 		if (vol_map[val] >= min_vol)
186 			break;
187 
188 	if (val > LDO_VOL_MAX_IDX || vol_map[val] > max_vol)
189 		return -EINVAL;
190 
191 	*selector = val;
192 
193 	return lp3971_set_bits(lp3971, LP3971_LDO_VOL_CONTR_REG(ldo),
194 			LDO_VOL_CONTR_MASK << LDO_VOL_CONTR_SHIFT(ldo),
195 			val << LDO_VOL_CONTR_SHIFT(ldo));
196 }
197 
198 static struct regulator_ops lp3971_ldo_ops = {
199 	.list_voltage = lp3971_ldo_list_voltage,
200 	.is_enabled = lp3971_ldo_is_enabled,
201 	.enable = lp3971_ldo_enable,
202 	.disable = lp3971_ldo_disable,
203 	.get_voltage = lp3971_ldo_get_voltage,
204 	.set_voltage = lp3971_ldo_set_voltage,
205 };
206 
lp3971_dcdc_list_voltage(struct regulator_dev * dev,unsigned index)207 static int lp3971_dcdc_list_voltage(struct regulator_dev *dev, unsigned index)
208 {
209 	return 1000 * buck_voltage_map[index];
210 }
211 
lp3971_dcdc_is_enabled(struct regulator_dev * dev)212 static int lp3971_dcdc_is_enabled(struct regulator_dev *dev)
213 {
214 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
215 	int buck = rdev_get_id(dev) - LP3971_DCDC1;
216 	u16 mask = 1 << (buck * 2);
217 	u16 val;
218 
219 	val = lp3971_reg_read(lp3971, LP3971_BUCK_VOL_ENABLE_REG);
220 	return (val & mask) != 0;
221 }
222 
lp3971_dcdc_enable(struct regulator_dev * dev)223 static int lp3971_dcdc_enable(struct regulator_dev *dev)
224 {
225 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
226 	int buck = rdev_get_id(dev) - LP3971_DCDC1;
227 	u16 mask = 1 << (buck * 2);
228 
229 	return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_ENABLE_REG, mask, mask);
230 }
231 
lp3971_dcdc_disable(struct regulator_dev * dev)232 static int lp3971_dcdc_disable(struct regulator_dev *dev)
233 {
234 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
235 	int buck = rdev_get_id(dev) - LP3971_DCDC1;
236 	u16 mask = 1 << (buck * 2);
237 
238 	return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_ENABLE_REG, mask, 0);
239 }
240 
lp3971_dcdc_get_voltage(struct regulator_dev * dev)241 static int lp3971_dcdc_get_voltage(struct regulator_dev *dev)
242 {
243 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
244 	int buck = rdev_get_id(dev) - LP3971_DCDC1;
245 	u16 reg;
246 	int val;
247 
248 	reg = lp3971_reg_read(lp3971, LP3971_BUCK_TARGET_VOL1_REG(buck));
249 	reg &= BUCK_TARGET_VOL_MASK;
250 
251 	if (reg <= BUCK_TARGET_VOL_MAX_IDX)
252 		val = 1000 * buck_voltage_map[reg];
253 	else {
254 		val = 0;
255 		dev_warn(&dev->dev, "chip reported incorrect voltage value.\n");
256 	}
257 
258 	return val;
259 }
260 
lp3971_dcdc_set_voltage(struct regulator_dev * dev,int min_uV,int max_uV,unsigned int * selector)261 static int lp3971_dcdc_set_voltage(struct regulator_dev *dev,
262 				   int min_uV, int max_uV,
263 				   unsigned int *selector)
264 {
265 	struct lp3971 *lp3971 = rdev_get_drvdata(dev);
266 	int buck = rdev_get_id(dev) - LP3971_DCDC1;
267 	int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
268 	const int *vol_map = buck_voltage_map;
269 	u16 val;
270 	int ret;
271 
272 	if (min_vol < vol_map[BUCK_TARGET_VOL_MIN_IDX] ||
273 	    min_vol > vol_map[BUCK_TARGET_VOL_MAX_IDX])
274 		return -EINVAL;
275 
276 	for (val = BUCK_TARGET_VOL_MIN_IDX; val <= BUCK_TARGET_VOL_MAX_IDX;
277 	     val++)
278 		if (vol_map[val] >= min_vol)
279 			break;
280 
281 	if (val > BUCK_TARGET_VOL_MAX_IDX || vol_map[val] > max_vol)
282 		return -EINVAL;
283 
284 	*selector = val;
285 
286 	ret = lp3971_set_bits(lp3971, LP3971_BUCK_TARGET_VOL1_REG(buck),
287 	       BUCK_TARGET_VOL_MASK, val);
288 	if (ret)
289 		return ret;
290 
291 	ret = lp3971_set_bits(lp3971, LP3971_BUCK_VOL_CHANGE_REG,
292 	       BUCK_VOL_CHANGE_FLAG_MASK << BUCK_VOL_CHANGE_SHIFT(buck),
293 	       BUCK_VOL_CHANGE_FLAG_GO << BUCK_VOL_CHANGE_SHIFT(buck));
294 	if (ret)
295 		return ret;
296 
297 	return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_CHANGE_REG,
298 	       BUCK_VOL_CHANGE_FLAG_MASK << BUCK_VOL_CHANGE_SHIFT(buck),
299 	       0 << BUCK_VOL_CHANGE_SHIFT(buck));
300 }
301 
302 static struct regulator_ops lp3971_dcdc_ops = {
303 	.list_voltage = lp3971_dcdc_list_voltage,
304 	.is_enabled = lp3971_dcdc_is_enabled,
305 	.enable = lp3971_dcdc_enable,
306 	.disable = lp3971_dcdc_disable,
307 	.get_voltage = lp3971_dcdc_get_voltage,
308 	.set_voltage = lp3971_dcdc_set_voltage,
309 };
310 
311 static struct regulator_desc regulators[] = {
312 	{
313 		.name = "LDO1",
314 		.id = LP3971_LDO1,
315 		.ops = &lp3971_ldo_ops,
316 		.n_voltages = ARRAY_SIZE(ldo123_voltage_map),
317 		.type = REGULATOR_VOLTAGE,
318 		.owner = THIS_MODULE,
319 	},
320 	{
321 		.name = "LDO2",
322 		.id = LP3971_LDO2,
323 		.ops = &lp3971_ldo_ops,
324 		.n_voltages = ARRAY_SIZE(ldo123_voltage_map),
325 		.type = REGULATOR_VOLTAGE,
326 		.owner = THIS_MODULE,
327 	},
328 	{
329 		.name = "LDO3",
330 		.id = LP3971_LDO3,
331 		.ops = &lp3971_ldo_ops,
332 		.n_voltages = ARRAY_SIZE(ldo123_voltage_map),
333 		.type = REGULATOR_VOLTAGE,
334 		.owner = THIS_MODULE,
335 	},
336 	{
337 		.name = "LDO4",
338 		.id = LP3971_LDO4,
339 		.ops = &lp3971_ldo_ops,
340 		.n_voltages = ARRAY_SIZE(ldo45_voltage_map),
341 		.type = REGULATOR_VOLTAGE,
342 		.owner = THIS_MODULE,
343 	},
344 	{
345 		.name = "LDO5",
346 		.id = LP3971_LDO5,
347 		.ops = &lp3971_ldo_ops,
348 		.n_voltages = ARRAY_SIZE(ldo45_voltage_map),
349 		.type = REGULATOR_VOLTAGE,
350 		.owner = THIS_MODULE,
351 	},
352 	{
353 		.name = "DCDC1",
354 		.id = LP3971_DCDC1,
355 		.ops = &lp3971_dcdc_ops,
356 		.n_voltages = ARRAY_SIZE(buck_voltage_map),
357 		.type = REGULATOR_VOLTAGE,
358 		.owner = THIS_MODULE,
359 	},
360 	{
361 		.name = "DCDC2",
362 		.id = LP3971_DCDC2,
363 		.ops = &lp3971_dcdc_ops,
364 		.n_voltages = ARRAY_SIZE(buck_voltage_map),
365 		.type = REGULATOR_VOLTAGE,
366 		.owner = THIS_MODULE,
367 	},
368 	{
369 		.name = "DCDC3",
370 		.id = LP3971_DCDC3,
371 		.ops = &lp3971_dcdc_ops,
372 		.n_voltages = ARRAY_SIZE(buck_voltage_map),
373 		.type = REGULATOR_VOLTAGE,
374 		.owner = THIS_MODULE,
375 	},
376 };
377 
lp3971_i2c_read(struct i2c_client * i2c,char reg,int count,u16 * dest)378 static int lp3971_i2c_read(struct i2c_client *i2c, char reg, int count,
379 	u16 *dest)
380 {
381 	int ret;
382 
383 	if (count != 1)
384 		return -EIO;
385 	ret = i2c_smbus_read_byte_data(i2c, reg);
386 	if (ret < 0)
387 		return -EIO;
388 
389 	*dest = ret;
390 	return 0;
391 }
392 
lp3971_i2c_write(struct i2c_client * i2c,char reg,int count,const u16 * src)393 static int lp3971_i2c_write(struct i2c_client *i2c, char reg, int count,
394 	const u16 *src)
395 {
396 	if (count != 1)
397 		return -EIO;
398 	return i2c_smbus_write_byte_data(i2c, reg, *src);
399 }
400 
lp3971_reg_read(struct lp3971 * lp3971,u8 reg)401 static u8 lp3971_reg_read(struct lp3971 *lp3971, u8 reg)
402 {
403 	u16 val = 0;
404 
405 	mutex_lock(&lp3971->io_lock);
406 
407 	lp3971_i2c_read(lp3971->i2c, reg, 1, &val);
408 
409 	dev_dbg(lp3971->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
410 		(unsigned)val&0xff);
411 
412 	mutex_unlock(&lp3971->io_lock);
413 
414 	return val & 0xff;
415 }
416 
lp3971_set_bits(struct lp3971 * lp3971,u8 reg,u16 mask,u16 val)417 static int lp3971_set_bits(struct lp3971 *lp3971, u8 reg, u16 mask, u16 val)
418 {
419 	u16 tmp;
420 	int ret;
421 
422 	mutex_lock(&lp3971->io_lock);
423 
424 	ret = lp3971_i2c_read(lp3971->i2c, reg, 1, &tmp);
425 	tmp = (tmp & ~mask) | val;
426 	if (ret == 0) {
427 		ret = lp3971_i2c_write(lp3971->i2c, reg, 1, &tmp);
428 		dev_dbg(lp3971->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
429 			(unsigned)val&0xff);
430 	}
431 	mutex_unlock(&lp3971->io_lock);
432 
433 	return ret;
434 }
435 
setup_regulators(struct lp3971 * lp3971,struct lp3971_platform_data * pdata)436 static int __devinit setup_regulators(struct lp3971 *lp3971,
437 				      struct lp3971_platform_data *pdata)
438 {
439 	int i, err;
440 
441 	lp3971->num_regulators = pdata->num_regulators;
442 	lp3971->rdev = kcalloc(pdata->num_regulators,
443 				sizeof(struct regulator_dev *), GFP_KERNEL);
444 	if (!lp3971->rdev) {
445 		err = -ENOMEM;
446 		goto err_nomem;
447 	}
448 
449 	/* Instantiate the regulators */
450 	for (i = 0; i < pdata->num_regulators; i++) {
451 		struct lp3971_regulator_subdev *reg = &pdata->regulators[i];
452 		lp3971->rdev[i] = regulator_register(&regulators[reg->id],
453 					lp3971->dev, reg->initdata, lp3971);
454 
455 		if (IS_ERR(lp3971->rdev[i])) {
456 			err = PTR_ERR(lp3971->rdev[i]);
457 			dev_err(lp3971->dev, "regulator init failed: %d\n",
458 				err);
459 			goto error;
460 		}
461 	}
462 
463 	return 0;
464 
465 error:
466 	while (--i >= 0)
467 		regulator_unregister(lp3971->rdev[i]);
468 	kfree(lp3971->rdev);
469 	lp3971->rdev = NULL;
470 err_nomem:
471 	return err;
472 }
473 
lp3971_i2c_probe(struct i2c_client * i2c,const struct i2c_device_id * id)474 static int __devinit lp3971_i2c_probe(struct i2c_client *i2c,
475 			    const struct i2c_device_id *id)
476 {
477 	struct lp3971 *lp3971;
478 	struct lp3971_platform_data *pdata = i2c->dev.platform_data;
479 	int ret;
480 	u16 val;
481 
482 	if (!pdata) {
483 		dev_dbg(&i2c->dev, "No platform init data supplied\n");
484 		return -ENODEV;
485 	}
486 
487 	lp3971 = kzalloc(sizeof(struct lp3971), GFP_KERNEL);
488 	if (lp3971 == NULL)
489 		return -ENOMEM;
490 
491 	lp3971->i2c = i2c;
492 	lp3971->dev = &i2c->dev;
493 
494 	mutex_init(&lp3971->io_lock);
495 
496 	/* Detect LP3971 */
497 	ret = lp3971_i2c_read(i2c, LP3971_SYS_CONTROL1_REG, 1, &val);
498 	if (ret == 0 && (val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL)
499 		ret = -ENODEV;
500 	if (ret < 0) {
501 		dev_err(&i2c->dev, "failed to detect device\n");
502 		goto err_detect;
503 	}
504 
505 	ret = setup_regulators(lp3971, pdata);
506 	if (ret < 0)
507 		goto err_detect;
508 
509 	i2c_set_clientdata(i2c, lp3971);
510 	return 0;
511 
512 err_detect:
513 	kfree(lp3971);
514 	return ret;
515 }
516 
lp3971_i2c_remove(struct i2c_client * i2c)517 static int __devexit lp3971_i2c_remove(struct i2c_client *i2c)
518 {
519 	struct lp3971 *lp3971 = i2c_get_clientdata(i2c);
520 	int i;
521 
522 	for (i = 0; i < lp3971->num_regulators; i++)
523 		regulator_unregister(lp3971->rdev[i]);
524 
525 	kfree(lp3971->rdev);
526 	kfree(lp3971);
527 
528 	return 0;
529 }
530 
531 static const struct i2c_device_id lp3971_i2c_id[] = {
532        { "lp3971", 0 },
533        { }
534 };
535 MODULE_DEVICE_TABLE(i2c, lp3971_i2c_id);
536 
537 static struct i2c_driver lp3971_i2c_driver = {
538 	.driver = {
539 		.name = "LP3971",
540 		.owner = THIS_MODULE,
541 	},
542 	.probe    = lp3971_i2c_probe,
543 	.remove   = __devexit_p(lp3971_i2c_remove),
544 	.id_table = lp3971_i2c_id,
545 };
546 
lp3971_module_init(void)547 static int __init lp3971_module_init(void)
548 {
549 	int ret;
550 
551 	ret = i2c_add_driver(&lp3971_i2c_driver);
552 	if (ret != 0)
553 		pr_err("Failed to register I2C driver: %d\n", ret);
554 
555 	return ret;
556 }
557 module_init(lp3971_module_init);
558 
lp3971_module_exit(void)559 static void __exit lp3971_module_exit(void)
560 {
561 	i2c_del_driver(&lp3971_i2c_driver);
562 }
563 module_exit(lp3971_module_exit);
564 
565 MODULE_LICENSE("GPL");
566 MODULE_AUTHOR("Marek Szyprowski <m.szyprowski@samsung.com>");
567 MODULE_DESCRIPTION("LP3971 PMIC driver");
568