aboutsummaryrefslogtreecommitdiff
path: root/drivers/mfd/ab8500-gpadc.c
blob: bc93b2e8230cec9382bcacdf9425e5c429703610 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * License Terms: GNU General Public License v2
 * Author: Arun R Murthy <arun.murthy@stericsson.com>
 * Author: Daniel Willerud <daniel.willerud@stericsson.com>
 * Author: Johan Palsson <johan.palsson@stericsson.com>
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/completion.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/mfd/ab8500.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/ab8500/gpadc.h>

/*
 * GPADC register offsets
 * Bank : 0x0A
 */
#define AB8500_GPADC_CTRL1_REG		0x00
#define AB8500_GPADC_CTRL2_REG		0x01
#define AB8500_GPADC_CTRL3_REG		0x02
#define AB8500_GPADC_AUTO_TIMER_REG	0x03
#define AB8500_GPADC_STAT_REG		0x04
#define AB8500_GPADC_MANDATAL_REG	0x05
#define AB8500_GPADC_MANDATAH_REG	0x06
#define AB8500_GPADC_AUTODATAL_REG	0x07
#define AB8500_GPADC_AUTODATAH_REG	0x08
#define AB8500_GPADC_MUX_CTRL_REG	0x09

/*
 * OTP register offsets
 * Bank : 0x15
 */
#define AB8500_GPADC_CAL_1		0x0F
#define AB8500_GPADC_CAL_2		0x10
#define AB8500_GPADC_CAL_3		0x11
#define AB8500_GPADC_CAL_4		0x12
#define AB8500_GPADC_CAL_5		0x13
#define AB8500_GPADC_CAL_6		0x14
#define AB8500_GPADC_CAL_7		0x15

/* gpadc constants */
#define EN_VINTCORE12			0x04
#define EN_VTVOUT			0x02
#define EN_GPADC			0x01
#define DIS_GPADC			0x00
#define SW_AVG_16			0x60
#define ADC_SW_CONV			0x04
#define EN_ICHAR			0x80
#define EN_BUF				0x40
#define DIS_ZERO			0x00
#define GPADC_BUSY			0x01

/* GPADC constants from AB8500 spec, UM0836 */
#define ADC_RESOLUTION			1024
#define ADC_CH_BTEMP_MIN		0
#define ADC_CH_BTEMP_MAX		1350
#define ADC_CH_DIETEMP_MIN		0
#define ADC_CH_DIETEMP_MAX		1350
#define ADC_CH_CHG_V_MIN		0
#define ADC_CH_CHG_V_MAX		20030
#define ADC_CH_ACCDET2_MIN		0
#define ADC_CH_ACCDET2_MAX		2500
#define ADC_CH_VBAT_MIN			2300
#define ADC_CH_VBAT_MAX			4800
#define ADC_CH_CHG_I_MIN		0
#define ADC_CH_CHG_I_MAX		1500
#define ADC_CH_BKBAT_MIN		0
#define ADC_CH_BKBAT_MAX		3200

/* This is used to not lose precision when dividing to get gain and offset */
#define CALIB_SCALE			1000

enum cal_channels {
	ADC_INPUT_VMAIN = 0,
	ADC_INPUT_BTEMP,
	ADC_INPUT_VBAT,
	NBR_CAL_INPUTS,
};

/**
 * struct adc_cal_data - Table for storing gain and offset for the calibrated
 * ADC channels
 * @gain:		Gain of the ADC channel
 * @offset:		Offset of the ADC channel
 */
struct adc_cal_data {
	u64 gain;
	u64 offset;
};

/**
 * struct ab8500_gpadc - AB8500 GPADC device information
 * @dev:			pointer to the struct device
 * @node:			a list of AB8500 GPADCs, hence prepared for
				reentrance
 * @ab8500_gpadc_complete:	pointer to the struct completion, to indicate
 *				the completion of gpadc conversion
 * @ab8500_gpadc_lock:		structure of type mutex
 * @regu:			pointer to the struct regulator
 * @irq:			interrupt number that is used by gpadc
 * @cal_data			array of ADC calibration data structs
 */
struct ab8500_gpadc {
	struct device *dev;
	struct list_head node;
	struct completion ab8500_gpadc_complete;
	struct mutex ab8500_gpadc_lock;
	struct regulator *regu;
	int irq;
	struct adc_cal_data cal_data[NBR_CAL_INPUTS];
};

static LIST_HEAD(ab8500_gpadc_list);

/**
 * ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC
 * (i.e. the first GPADC in the instance list)
 */
struct ab8500_gpadc *ab8500_gpadc_get(char *name)
{
	struct ab8500_gpadc *gpadc;

	list_for_each_entry(gpadc, &ab8500_gpadc_list, node) {
		if (!strcmp(name, dev_name(gpadc->dev)))
		    return gpadc;
	}

	return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(ab8500_gpadc_get);

static int ab8500_gpadc_ad_to_voltage(struct ab8500_gpadc *gpadc, u8 input,
	int ad_value)
{
	int res;

	switch (input) {
	case MAIN_CHARGER_V:
		/* For some reason we don't have calibrated data */
		if (!gpadc->cal_data[ADC_INPUT_VMAIN].gain) {
			res = ADC_CH_CHG_V_MIN + (ADC_CH_CHG_V_MAX -
				ADC_CH_CHG_V_MIN) * ad_value /
				ADC_RESOLUTION;
			break;
		}
		/* Here we can use the calibrated data */
		res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VMAIN].gain +
			gpadc->cal_data[ADC_INPUT_VMAIN].offset) / CALIB_SCALE;
		break;

	case BAT_CTRL:
	case BTEMP_BALL:
	case ACC_DETECT1:
	case ADC_AUX1:
	case ADC_AUX2:
		/* For some reason we don't have calibrated data */
		if (!gpadc->cal_data[ADC_INPUT_BTEMP].gain) {
			res = ADC_CH_BTEMP_MIN + (ADC_CH_BTEMP_MAX -
				ADC_CH_BTEMP_MIN) * ad_value /
				ADC_RESOLUTION;
			break;
		}
		/* Here we can use the calibrated data */
		res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_BTEMP].gain +
			gpadc->cal_data[ADC_INPUT_BTEMP].offset) / CALIB_SCALE;
		break;

	case MAIN_BAT_V:
		/* For some reason we don't have calibrated data */
		if (!gpadc->cal_data[ADC_INPUT_VBAT].gain) {
			res = ADC_CH_VBAT_MIN + (ADC_CH_VBAT_MAX -
				ADC_CH_VBAT_MIN) * ad_value /
				ADC_RESOLUTION;
			break;
		}
		/* Here we can use the calibrated data */
		res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VBAT].gain +
			gpadc->cal_data[ADC_INPUT_VBAT].offset) / CALIB_SCALE;
		break;

	case DIE_TEMP:
		res = ADC_CH_DIETEMP_MIN +
			(ADC_CH_DIETEMP_MAX - ADC_CH_DIETEMP_MIN) * ad_value /
			ADC_RESOLUTION;
		break;

	case ACC_DETECT2:
		res = ADC_CH_ACCDET2_MIN +
			(ADC_CH_ACCDET2_MAX - ADC_CH_ACCDET2_MIN) * ad_value /
			ADC_RESOLUTION;
		break;

	case VBUS_V:
		res = ADC_CH_CHG_V_MIN +
			(ADC_CH_CHG_V_MAX - ADC_CH_CHG_V_MIN) * ad_value /
			ADC_RESOLUTION;
		break;

	case MAIN_CHARGER_C:
	case USB_CHARGER_C:
		res = ADC_CH_CHG_I_MIN +
			(ADC_CH_CHG_I_MAX - ADC_CH_CHG_I_MIN) * ad_value /
			ADC_RESOLUTION;
		break;

	case BK_BAT_V:
		res = ADC_CH_BKBAT_MIN +
			(ADC_CH_BKBAT_MAX - ADC_CH_BKBAT_MIN) * ad_value /
			ADC_RESOLUTION;
		break;

	default:
		dev_err(gpadc->dev,
			"unknown channel, not possible to convert\n");
		res = -EINVAL;
		break;

	}
	return res;
}

/**
 * ab8500_gpadc_convert() - gpadc conversion
 * @input:	analog input to be converted to digital data
 *
 * This function converts the selected analog i/p to digital
 * data.
 */
int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input)
{
	int ret;
	u16 data = 0;
	int looplimit = 0;
	u8 val, low_data, high_data;

	if (!gpadc)
		return -ENODEV;

	mutex_lock(&gpadc->ab8500_gpadc_lock);
	/* Enable VTVout LDO this is required for GPADC */
	regulator_enable(gpadc->regu);

	/* Check if ADC is not busy, lock and proceed */
	do {
		ret = abx500_get_register_interruptible(gpadc->dev,
			AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);
		if (ret < 0)
			goto out;
		if (!(val & GPADC_BUSY))
			break;
		msleep(10);
	} while (++looplimit < 10);
	if (looplimit >= 10 && (val & GPADC_BUSY)) {
		dev_err(gpadc->dev, "gpadc_conversion: GPADC busy");
		ret = -EINVAL;
		goto out;
	}

	/* Enable GPADC */
	ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
		AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
	if (ret < 0) {
		dev_err(gpadc->dev, "gpadc_conversion: enable gpadc failed\n");
		goto out;
	}
	/* Select the input source and set average samples to 16 */
	ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
		AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16));
	if (ret < 0) {
		dev_err(gpadc->dev,
			"gpadc_conversion: set avg samples failed\n");
		goto out;
	}
	/*
	 * Enable ADC, buffering, select rising edge and enable ADC path
	 * charging current sense if it needed
	 */
	switch (input) {
	case MAIN_CHARGER_C:
	case USB_CHARGER_C:
		ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
			AB8500_GPADC, AB8500_GPADC_CTRL1_REG,
			EN_BUF | EN_ICHAR,
			EN_BUF | EN_ICHAR);
		break;
	default:
		ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
			AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
		break;
	}
	if (ret < 0) {
		dev_err(gpadc->dev,
			"gpadc_conversion: select falling edge failed\n");
		goto out;
	}
	ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
		AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
	if (ret < 0) {
		dev_err(gpadc->dev,
			"gpadc_conversion: start s/w conversion failed\n");
		goto out;
	}
	/* wait for completion of conversion */
	if (!wait_for_completion_timeout(&gpadc->ab8500_gpadc_complete, 2*HZ)) {
		dev_err(gpadc->dev,
			"timeout: didnt recieve GPADC conversion interrupt\n");
		ret = -EINVAL;
		goto out;
	}

	/* Read the converted RAW data */
	ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
		AB8500_GPADC_MANDATAL_REG, &low_data);
	if (ret < 0) {
		dev_err(gpadc->dev, "gpadc_conversion: read low data failed\n");
		goto out;
	}

	ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
		AB8500_GPADC_MANDATAH_REG, &high_data);
	if (ret < 0) {
		dev_err(gpadc->dev,
			"gpadc_conversion: read high data failed\n");
		goto out;
	}

	data = (high_data << 8) | low_data;
	/* Disable GPADC */
	ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
		AB8500_GPADC_CTRL1_REG, DIS_GPADC);
	if (ret < 0) {
		dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");
		goto out;
	}
	/* Disable VTVout LDO this is required for GPADC */
	regulator_disable(gpadc->regu);
	mutex_unlock(&gpadc->ab8500_gpadc_lock);
	ret = ab8500_gpadc_ad_to_voltage(gpadc, input, data);
	return ret;

out:
	/*
	 * It has shown to be needed to turn off the GPADC if an error occurs,
	 * otherwise we might have problem when waiting for the busy bit in the
	 * GPADC status register to go low. In V1.1 there wait_for_completion
	 * seems to timeout when waiting for an interrupt.. Not seen in V2.0
	 */
	(void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
		AB8500_GPADC_CTRL1_REG, DIS_GPADC);
	regulator_disable(gpadc->regu);
	mutex_unlock(&gpadc->ab8500_gpadc_lock);
	dev_err(gpadc->dev,
		"gpadc_conversion: Failed to AD convert channel %d\n", input);
	return ret;
}
EXPORT_SYMBOL(ab8500_gpadc_convert);

/**
 * ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion
 * @irq:	irq number
 * @data:	pointer to the data passed during request irq
 *
 * This is a interrupt service routine for s/w gpadc conversion completion.
 * Notifies the gpadc completion is completed and the converted raw value
 * can be read from the registers.
 * Returns IRQ status(IRQ_HANDLED)
 */
static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc)
{
	struct ab8500_gpadc *gpadc = _gpadc;

	complete(&gpadc->ab8500_gpadc_complete);

	return IRQ_HANDLED;
}

static int otp_cal_regs[] = {
	AB8500_GPADC_CAL_1,
	AB8500_GPADC_CAL_2,
	AB8500_GPADC_CAL_3,
	AB8500_GPADC_CAL_4,
	AB8500_GPADC_CAL_5,
	AB8500_GPADC_CAL_6,
	AB8500_GPADC_CAL_7,
};

static void ab8500_gpadc_read_calibration_data(struct ab8500_gpadc *gpadc)
{
	int i;
	int ret[ARRAY_SIZE(otp_cal_regs)];
	u8 gpadc_cal[ARRAY_SIZE(otp_cal_regs)];

	int vmain_high, vmain_low;
	int btemp_high, btemp_low;
	int vbat_high, vbat_low;

	/* First we read all OTP registers and store the error code */
	for (i = 0; i < ARRAY_SIZE(otp_cal_regs); i++) {
		ret[i] = abx500_get_register_interruptible(gpadc->dev,
			AB8500_OTP_EMUL, otp_cal_regs[i],  &gpadc_cal[i]);
		if (ret[i] < 0)
			dev_err(gpadc->dev, "%s: read otp reg 0x%02x failed\n",
				__func__, otp_cal_regs[i]);
	}

	/*
	 * The ADC calibration data is stored in OTP registers.
	 * The layout of the calibration data is outlined below and a more
	 * detailed description can be found in UM0836
	 *
	 * vm_h/l = vmain_high/low
	 * bt_h/l = btemp_high/low
	 * vb_h/l = vbat_high/low
	 *
	 * Data bits:
	 * | 7	   | 6	   | 5	   | 4	   | 3	   | 2	   | 1	   | 0
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * |						   | vm_h9 | vm_h8
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * |		   | vm_h7 | vm_h6 | vm_h5 | vm_h4 | vm_h3 | vm_h2
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vm_h1 | vm_h0 | vm_l4 | vm_l3 | vm_l2 | vm_l1 | vm_l0 | bt_h9
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | bt_h8 | bt_h7 | bt_h6 | bt_h5 | bt_h4 | bt_h3 | bt_h2 | bt_h1
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | bt_h0 | bt_l4 | bt_l3 | bt_l2 | bt_l1 | bt_l0 | vb_h9 | vb_h8
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vb_h7 | vb_h6 | vb_h5 | vb_h4 | vb_h3 | vb_h2 | vb_h1 | vb_h0
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vb_l5 | vb_l4 | vb_l3 | vb_l2 | vb_l1 | vb_l0 |
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 *
	 *
	 * Ideal output ADC codes corresponding to injected input voltages
	 * during manufacturing is:
	 *
	 * vmain_high: Vin = 19500mV / ADC ideal code = 997
	 * vmain_low:  Vin = 315mV   / ADC ideal code = 16
	 * btemp_high: Vin = 1300mV  / ADC ideal code = 985
	 * btemp_low:  Vin = 21mV    / ADC ideal code = 16
	 * vbat_high:  Vin = 4700mV  / ADC ideal code = 982
	 * vbat_low:   Vin = 2380mV  / ADC ideal code = 33
	 */

	/* Calculate gain and offset for VMAIN if all reads succeeded */
	if (!(ret[0] < 0 || ret[1] < 0 || ret[2] < 0)) {
		vmain_high = (((gpadc_cal[0] & 0x03) << 8) |
			((gpadc_cal[1] & 0x3F) << 2) |
			((gpadc_cal[2] & 0xC0) >> 6));

		vmain_low = ((gpadc_cal[2] & 0x3E) >> 1);

		gpadc->cal_data[ADC_INPUT_VMAIN].gain = CALIB_SCALE *
			(19500 - 315) /	(vmain_high - vmain_low);

		gpadc->cal_data[ADC_INPUT_VMAIN].offset = CALIB_SCALE * 19500 -
			(CALIB_SCALE * (19500 - 315) /
			 (vmain_high - vmain_low)) * vmain_high;
	} else {
		gpadc->cal_data[ADC_INPUT_VMAIN].gain = 0;
	}

	/* Calculate gain and offset for BTEMP if all reads succeeded */
	if (!(ret[2] < 0 || ret[3] < 0 || ret[4] < 0)) {
		btemp_high = (((gpadc_cal[2] & 0x01) << 9) |
			(gpadc_cal[3] << 1) |
			((gpadc_cal[4] & 0x80) >> 7));

		btemp_low = ((gpadc_cal[4] & 0x7C) >> 2);

		gpadc->cal_data[ADC_INPUT_BTEMP].gain =
			CALIB_SCALE * (1300 - 21) / (btemp_high - btemp_low);

		gpadc->cal_data[ADC_INPUT_BTEMP].offset = CALIB_SCALE * 1300 -
			(CALIB_SCALE * (1300 - 21) /
			(btemp_high - btemp_low)) * btemp_high;
	} else {
		gpadc->cal_data[ADC_INPUT_BTEMP].gain = 0;
	}

	/* Calculate gain and offset for VBAT if all reads succeeded */
	if (!(ret[4] < 0 || ret[5] < 0 || ret[6] < 0)) {
		vbat_high = (((gpadc_cal[4] & 0x03) << 8) | gpadc_cal[5]);
		vbat_low = ((gpadc_cal[6] & 0xFC) >> 2);

		gpadc->cal_data[ADC_INPUT_VBAT].gain = CALIB_SCALE *
			(4700 - 2380) /	(vbat_high - vbat_low);

		gpadc->cal_data[ADC_INPUT_VBAT].offset = CALIB_SCALE * 4700 -
			(CALIB_SCALE * (4700 - 2380) /
			(vbat_high - vbat_low)) * vbat_high;
	} else {
		gpadc->cal_data[ADC_INPUT_VBAT].gain = 0;
	}

	dev_dbg(gpadc->dev, "VMAIN gain %llu offset %llu\n",
		gpadc->cal_data[ADC_INPUT_VMAIN].gain,
		gpadc->cal_data[ADC_INPUT_VMAIN].offset);

	dev_dbg(gpadc->dev, "BTEMP gain %llu offset %llu\n",
		gpadc->cal_data[ADC_INPUT_BTEMP].gain,
		gpadc->cal_data[ADC_INPUT_BTEMP].offset);

	dev_dbg(gpadc->dev, "VBAT gain %llu offset %llu\n",
		gpadc->cal_data[ADC_INPUT_VBAT].gain,
		gpadc->cal_data[ADC_INPUT_VBAT].offset);
}

static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
{
	int ret = 0;
	struct ab8500_gpadc *gpadc;

	gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
	if (!gpadc) {
		dev_err(&pdev->dev, "Error: No memory\n");
		return -ENOMEM;
	}

	gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
	if (gpadc->irq < 0) {
		dev_err(gpadc->dev, "failed to get platform irq-%d\n",
			gpadc->irq);
		ret = gpadc->irq;
		goto fail;
	}

	gpadc->dev = &pdev->dev;
	mutex_init(&gpadc->ab8500_gpadc_lock);

	/* Initialize completion used to notify completion of conversion */
	init_completion(&gpadc->ab8500_gpadc_complete);

	/* Register interrupt  - SwAdcComplete */
	ret = request_threaded_irq(gpadc->irq, NULL,
		ab8500_bm_gpswadcconvend_handler,
		IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc", gpadc);
	if (ret < 0) {
		dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n",
			gpadc->irq);
		goto fail;
	}

	/* VTVout LDO used to power up ab8500-GPADC */
	gpadc->regu = regulator_get(&pdev->dev, "vddadc");
	if (IS_ERR(gpadc->regu)) {
		ret = PTR_ERR(gpadc->regu);
		dev_err(gpadc->dev, "failed to get vtvout LDO\n");
		goto fail_irq;
	}
	ab8500_gpadc_read_calibration_data(gpadc);
	list_add_tail(&gpadc->node, &ab8500_gpadc_list);
	dev_dbg(gpadc->dev, "probe success\n");
	return 0;
fail_irq:
	free_irq(gpadc->irq, gpadc);
fail:
	kfree(gpadc);
	gpadc = NULL;
	return ret;
}

static int __devexit ab8500_gpadc_remove(struct platform_device *pdev)
{
	struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);

	/* remove this gpadc entry from the list */
	list_del(&gpadc->node);
	/* remove interrupt  - completion of Sw ADC conversion */
	free_irq(gpadc->irq, gpadc);
	/* disable VTVout LDO that is being used by GPADC */
	regulator_put(gpadc->regu);
	kfree(gpadc);
	gpadc = NULL;
	return 0;
}

static struct platform_driver ab8500_gpadc_driver = {
	.probe = ab8500_gpadc_probe,
	.remove = __devexit_p(ab8500_gpadc_remove),
	.driver = {
		.name = "ab8500-gpadc",
		.owner = THIS_MODULE,
	},
};

static int __init ab8500_gpadc_init(void)
{
	return platform_driver_register(&ab8500_gpadc_driver);
}

static void __exit ab8500_gpadc_exit(void)
{
	platform_driver_unregister(&ab8500_gpadc_driver);
}

subsys_initcall_sync(ab8500_gpadc_init);
module_exit(ab8500_gpadc_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Arun R Murthy, Daniel Willerud, Johan Palsson");
MODULE_ALIAS("platform:ab8500_gpadc");
MODULE_DESCRIPTION("AB8500 GPADC driver");