aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/misc/ad525x_dpot.c
blob: 5e6fa8449e8b7bba11c2aca88fce59f34b80277e (plain) (blame)
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
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
/*
 * ad525x_dpot: Driver for the Analog Devices digital potentiometers
 * Copyright (c) 2009-2010 Analog Devices, Inc.
 * Author: Michael Hennerich <hennerich@blackfin.uclinux.org>
 *
 * DEVID		#Wipers		#Positions 	Resistor Options (kOhm)
 * AD5258		1		64		1, 10, 50, 100
 * AD5259		1		256		5, 10, 50, 100
 * AD5251		2		64		1, 10, 50, 100
 * AD5252		2		256		1, 10, 50, 100
 * AD5255		3		512		25, 250
 * AD5253		4		64		1, 10, 50, 100
 * AD5254		4		256		1, 10, 50, 100
 * AD5160		1		256		5, 10, 50, 100
 * AD5161		1		256		5, 10, 50, 100
 * AD5162		2		256		2.5, 10, 50, 100
 * AD5165		1		256		100
 * AD5200		1		256		10, 50
 * AD5201		1		33		10, 50
 * AD5203		4		64		10, 100
 * AD5204		4		256		10, 50, 100
 * AD5206		6		256		10, 50, 100
 * AD5207		2		256		10, 50, 100
 * AD5231		1		1024		10, 50, 100
 * AD5232		2		256		10, 50, 100
 * AD5233		4		64		10, 50, 100
 * AD5235		2		1024		25, 250
 * AD5260		1		256		20, 50, 200
 * AD5262		2		256		20, 50, 200
 * AD5263		4		256		20, 50, 200
 * AD5290		1		256		10, 50, 100
 * AD5291		1		256		20
 * AD5292		1		1024		20
 * AD5293		1		1024		20
 * AD7376		1		128		10, 50, 100, 1M
 * AD8400		1		256		1, 10, 50, 100
 * AD8402		2		256		1, 10, 50, 100
 * AD8403		4		256		1, 10, 50, 100
 * ADN2850		3		512		25, 250
 * AD5241		1		256		10, 100, 1M
 * AD5246		1		128		5, 10, 50, 100
 * AD5247		1		128		5, 10, 50, 100
 * AD5245		1		256		5, 10, 50, 100
 * AD5243		2		256		2.5, 10, 50, 100
 * AD5248		2		256		2.5, 10, 50, 100
 * AD5242		2		256		20, 50, 200
 * AD5280		1		256		20, 50, 200
 * AD5282		2		256		20, 50, 200
 * ADN2860		3		512		25, 250
 * AD5273		1		64		1, 10, 50, 100 (OTP)
 * AD5171		1		64		5, 10, 50, 100 (OTP)
 * AD5170		1		256		2.5, 10, 50, 100 (OTP)
 * AD5172		2		256		2.5, 10, 50, 100 (OTP)
 * AD5173		2		256		2.5, 10, 50, 100 (OTP)
 *
 * See Documentation/misc-devices/ad525x_dpot.txt for more info.
 *
 * derived from ad5258.c
 * Copyright (c) 2009 Cyber Switching, Inc.
 * Author: Chris Verges <chrisv@cyberswitching.com>
 *
 * derived from ad5252.c
 * Copyright (c) 2006 Michael Hennerich <hennerich@blackfin.uclinux.org>
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>

#define DRIVER_VERSION			"0.2"

#include "ad525x_dpot.h"

/*
 * Client data (each client gets its own)
 */

struct dpot_data {
	struct ad_dpot_bus_data	bdata;
	struct mutex update_lock;
	unsigned rdac_mask;
	unsigned max_pos;
	unsigned long devid;
	unsigned uid;
	unsigned feat;
	unsigned wipers;
	u16 rdac_cache[MAX_RDACS];
	DECLARE_BITMAP(otp_en_mask, MAX_RDACS);
};

static inline int dpot_read_d8(struct dpot_data *dpot)
{
	return dpot->bdata.bops->read_d8(dpot->bdata.client);
}

static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg)
{
	return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg);
}

static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg)
{
	return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg);
}

static inline int dpot_write_d8(struct dpot_data *dpot, u8 val)
{
	return dpot->bdata.bops->write_d8(dpot->bdata.client, val);
}

static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val)
{
	return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val);
}

static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val)
{
	return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val);
}

static s32 dpot_read_spi(struct dpot_data *dpot, u8 reg)
{
	unsigned ctrl = 0;

	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {

		if (dpot->feat & F_RDACS_WONLY)
			return dpot->rdac_cache[reg & DPOT_RDAC_MASK];

		if (dpot->uid == DPOT_UID(AD5291_ID) ||
			dpot->uid == DPOT_UID(AD5292_ID) ||
			dpot->uid == DPOT_UID(AD5293_ID))
			return dpot_read_r8d8(dpot,
				DPOT_AD5291_READ_RDAC << 2);

		ctrl = DPOT_SPI_READ_RDAC;
	} else if (reg & DPOT_ADDR_EEPROM) {
		ctrl = DPOT_SPI_READ_EEPROM;
	}

	if (dpot->feat & F_SPI_16BIT)
		return dpot_read_r8d8(dpot, ctrl);
	else if (dpot->feat & F_SPI_24BIT)
		return dpot_read_r8d16(dpot, ctrl);

	return -EFAULT;
}

static s32 dpot_read_i2c(struct dpot_data *dpot, u8 reg)
{
	unsigned ctrl = 0;
	switch (dpot->uid) {
	case DPOT_UID(AD5246_ID):
	case DPOT_UID(AD5247_ID):
		return dpot_read_d8(dpot);
	case DPOT_UID(AD5245_ID):
	case DPOT_UID(AD5241_ID):
	case DPOT_UID(AD5242_ID):
	case DPOT_UID(AD5243_ID):
	case DPOT_UID(AD5248_ID):
	case DPOT_UID(AD5280_ID):
	case DPOT_UID(AD5282_ID):
		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
			0 : DPOT_AD5291_RDAC_AB;
		return dpot_read_r8d8(dpot, ctrl);
	case DPOT_UID(AD5170_ID):
	case DPOT_UID(AD5171_ID):
	case DPOT_UID(AD5273_ID):
			return dpot_read_d8(dpot);
	case DPOT_UID(AD5172_ID):
	case DPOT_UID(AD5173_ID):
		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
			0 : DPOT_AD5272_3_A0;
		return dpot_read_r8d8(dpot, ctrl);
	default:
		if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
			return dpot_read_r8d16(dpot, (reg & 0xF8) |
					((reg & 0x7) << 1));
		else
			return dpot_read_r8d8(dpot, reg);
	}
}

static s32 dpot_read(struct dpot_data *dpot, u8 reg)
{
	if (dpot->feat & F_SPI)
		return dpot_read_spi(dpot, reg);
	else
		return dpot_read_i2c(dpot, reg);
}

static s32 dpot_write_spi(struct dpot_data *dpot, u8 reg, u16 value)
{
	unsigned val = 0;

	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
		if (dpot->feat & F_RDACS_WONLY)
			dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value;

		if (dpot->feat & F_AD_APPDATA) {
			if (dpot->feat & F_SPI_8BIT) {
				val = ((reg & DPOT_RDAC_MASK) <<
					DPOT_MAX_POS(dpot->devid)) |
					value;
				return dpot_write_d8(dpot, val);
			} else if (dpot->feat & F_SPI_16BIT) {
				val = ((reg & DPOT_RDAC_MASK) <<
					DPOT_MAX_POS(dpot->devid)) |
					value;
				return dpot_write_r8d8(dpot, val >> 8,
					val & 0xFF);
			} else
				BUG();
		} else {
			if (dpot->uid == DPOT_UID(AD5291_ID) ||
				dpot->uid == DPOT_UID(AD5292_ID) ||
				dpot->uid == DPOT_UID(AD5293_ID))
				return dpot_write_r8d8(dpot,
					(DPOT_AD5291_RDAC << 2) |
					(value >> 8), value & 0xFF);

			val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK);
		}
	} else if (reg & DPOT_ADDR_EEPROM) {
		val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK);
	} else if (reg & DPOT_ADDR_CMD) {
		switch (reg) {
		case DPOT_DEC_ALL_6DB:
			val = DPOT_SPI_DEC_ALL_6DB;
			break;
		case DPOT_INC_ALL_6DB:
			val = DPOT_SPI_INC_ALL_6DB;
			break;
		case DPOT_DEC_ALL:
			val = DPOT_SPI_DEC_ALL;
			break;
		case DPOT_INC_ALL:
			val = DPOT_SPI_INC_ALL;
			break;
		}
	} else
		BUG();

	if (dpot->feat & F_SPI_16BIT)
		return dpot_write_r8d8(dpot, val, value);
	else if (dpot->feat & F_SPI_24BIT)
		return dpot_write_r8d16(dpot, val, value);

	return -EFAULT;
}

static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
{
	/* Only write the instruction byte for certain commands */
	unsigned tmp = 0, ctrl = 0;

	switch (dpot->uid) {
	case DPOT_UID(AD5246_ID):
	case DPOT_UID(AD5247_ID):
		return dpot_write_d8(dpot, value);
		break;

	case DPOT_UID(AD5245_ID):
	case DPOT_UID(AD5241_ID):
	case DPOT_UID(AD5242_ID):
	case DPOT_UID(AD5243_ID):
	case DPOT_UID(AD5248_ID):
	case DPOT_UID(AD5280_ID):
	case DPOT_UID(AD5282_ID):
		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
			0 : DPOT_AD5291_RDAC_AB;
		return dpot_write_r8d8(dpot, ctrl, value);
		break;
	case DPOT_UID(AD5171_ID):
	case DPOT_UID(AD5273_ID):
		if (reg & DPOT_ADDR_OTP) {
			tmp = dpot_read_d8(dpot);
			if (tmp >> 6) /* Ready to Program? */
				return -EFAULT;
			ctrl = DPOT_AD5273_FUSE;
		}
		return dpot_write_r8d8(dpot, ctrl, value);
		break;
	case DPOT_UID(AD5172_ID):
	case DPOT_UID(AD5173_ID):
		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
			0 : DPOT_AD5272_3_A0;
		if (reg & DPOT_ADDR_OTP) {
			tmp = dpot_read_r8d16(dpot, ctrl);
			if (tmp >> 14) /* Ready to Program? */
				return -EFAULT;
			ctrl |= DPOT_AD5270_2_3_FUSE;
		}
		return dpot_write_r8d8(dpot, ctrl, value);
		break;
	case DPOT_UID(AD5170_ID):
		if (reg & DPOT_ADDR_OTP) {
			tmp = dpot_read_r8d16(dpot, tmp);
			if (tmp >> 14) /* Ready to Program? */
				return -EFAULT;
			ctrl = DPOT_AD5270_2_3_FUSE;
		}
		return dpot_write_r8d8(dpot, ctrl, value);
		break;
	default:
		if (reg & DPOT_ADDR_CMD)
			return dpot_write_d8(dpot, reg);

		if (dpot->max_pos > 256)
			return dpot_write_r8d16(dpot, (reg & 0xF8) |
						((reg & 0x7) << 1), value);
		else
			/* All other registers require instruction + data bytes */
			return dpot_write_r8d8(dpot, reg, value);
	}
}


static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
{
	if (dpot->feat & F_SPI)
		return dpot_write_spi(dpot, reg, value);
	else
		return dpot_write_i2c(dpot, reg, value);
}

/* sysfs functions */

static ssize_t sysfs_show_reg(struct device *dev,
			      struct device_attribute *attr,
			      char *buf, u32 reg)
{
	struct dpot_data *data = dev_get_drvdata(dev);
	s32 value;

	if (reg & DPOT_ADDR_OTP_EN)
		return sprintf(buf, "%s\n",
			test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask) ?
			"enabled" : "disabled");


	mutex_lock(&data->update_lock);
	value = dpot_read(data, reg);
	mutex_unlock(&data->update_lock);

	if (value < 0)
		return -EINVAL;
	/*
	 * Let someone else deal with converting this ...
	 * the tolerance is a two-byte value where the MSB
	 * is a sign + integer value, and the LSB is a
	 * decimal value.  See page 18 of the AD5258
	 * datasheet (Rev. A) for more details.
	 */

	if (reg & DPOT_REG_TOL)
		return sprintf(buf, "0x%04x\n", value & 0xFFFF);
	else
		return sprintf(buf, "%u\n", value & data->rdac_mask);
}

static ssize_t sysfs_set_reg(struct device *dev,
			     struct device_attribute *attr,
			     const char *buf, size_t count, u32 reg)
{
	struct dpot_data *data = dev_get_drvdata(dev);
	unsigned long value;
	int err;

	if (reg & DPOT_ADDR_OTP_EN) {
		if (!strncmp(buf, "enabled", sizeof("enabled")))
			set_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
		else
			clear_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);

		return count;
	}

	if ((reg & DPOT_ADDR_OTP) &&
		!test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask))
		return -EPERM;

	err = strict_strtoul(buf, 10, &value);
	if (err)
		return err;

	if (value > data->rdac_mask)
		value = data->rdac_mask;

	mutex_lock(&data->update_lock);
	dpot_write(data, reg, value);
	if (reg & DPOT_ADDR_EEPROM)
		msleep(26);	/* Sleep while the EEPROM updates */
	else if (reg & DPOT_ADDR_OTP)
		msleep(400);	/* Sleep while the OTP updates */
	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t sysfs_do_cmd(struct device *dev,
			    struct device_attribute *attr,
			    const char *buf, size_t count, u32 reg)
{
	struct dpot_data *data = dev_get_drvdata(dev);

	mutex_lock(&data->update_lock);
	dpot_write(data, reg, 0);
	mutex_unlock(&data->update_lock);

	return count;
}

/* ------------------------------------------------------------------------- */

#define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
show_##_name(struct device *dev, \
			  struct device_attribute *attr, char *buf) \
{ \
	return sysfs_show_reg(dev, attr, buf, _reg); \
}

#define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
set_##_name(struct device *dev, \
			 struct device_attribute *attr, \
			 const char *buf, size_t count) \
{ \
	return sysfs_set_reg(dev, attr, buf, count, _reg); \
}

#define DPOT_DEVICE_SHOW_SET(name, reg) \
DPOT_DEVICE_SHOW(name, reg) \
DPOT_DEVICE_SET(name, reg) \
static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name);

#define DPOT_DEVICE_SHOW_ONLY(name, reg) \
DPOT_DEVICE_SHOW(name, reg) \
static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL);

DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
DPOT_DEVICE_SHOW_SET(otp0, DPOT_ADDR_OTP | DPOT_RDAC0);
DPOT_DEVICE_SHOW_SET(otp0en, DPOT_ADDR_OTP_EN | DPOT_RDAC0);

DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
DPOT_DEVICE_SHOW_SET(otp1, DPOT_ADDR_OTP | DPOT_RDAC1);
DPOT_DEVICE_SHOW_SET(otp1en, DPOT_ADDR_OTP_EN | DPOT_RDAC1);

DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
DPOT_DEVICE_SHOW_SET(otp2, DPOT_ADDR_OTP | DPOT_RDAC2);
DPOT_DEVICE_SHOW_SET(otp2en, DPOT_ADDR_OTP_EN | DPOT_RDAC2);

DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
DPOT_DEVICE_SHOW_SET(otp3, DPOT_ADDR_OTP | DPOT_RDAC3);
DPOT_DEVICE_SHOW_SET(otp3en, DPOT_ADDR_OTP_EN | DPOT_RDAC3);

DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
DPOT_DEVICE_SHOW_SET(otp4, DPOT_ADDR_OTP | DPOT_RDAC4);
DPOT_DEVICE_SHOW_SET(otp4en, DPOT_ADDR_OTP_EN | DPOT_RDAC4);

DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
DPOT_DEVICE_SHOW_SET(otp5, DPOT_ADDR_OTP | DPOT_RDAC5);
DPOT_DEVICE_SHOW_SET(otp5en, DPOT_ADDR_OTP_EN | DPOT_RDAC5);

static const struct attribute *dpot_attrib_wipers[] = {
	&dev_attr_rdac0.attr,
	&dev_attr_rdac1.attr,
	&dev_attr_rdac2.attr,
	&dev_attr_rdac3.attr,
	&dev_attr_rdac4.attr,
	&dev_attr_rdac5.attr,
	NULL
};

static const struct attribute *dpot_attrib_eeprom[] = {
	&dev_attr_eeprom0.attr,
	&dev_attr_eeprom1.attr,
	&dev_attr_eeprom2.attr,
	&dev_attr_eeprom3.attr,
	&dev_attr_eeprom4.attr,
	&dev_attr_eeprom5.attr,
	NULL
};

static const struct attribute *dpot_attrib_otp[] = {
	&dev_attr_otp0.attr,
	&dev_attr_otp1.attr,
	&dev_attr_otp2.attr,
	&dev_attr_otp3.attr,
	&dev_attr_otp4.attr,
	&dev_attr_otp5.attr,
	NULL
};

static const struct attribute *dpot_attrib_otp_en[] = {
	&dev_attr_otp0en.attr,
	&dev_attr_otp1en.attr,
	&dev_attr_otp2en.attr,
	&dev_attr_otp3en.attr,
	&dev_attr_otp4en.attr,
	&dev_attr_otp5en.attr,
	NULL
};

static const struct attribute *dpot_attrib_tolerance[] = {
	&dev_attr_tolerance0.attr,
	&dev_attr_tolerance1.attr,
	&dev_attr_tolerance2.attr,
	&dev_attr_tolerance3.attr,
	&dev_attr_tolerance4.attr,
	&dev_attr_tolerance5.attr,
	NULL
};

/* ------------------------------------------------------------------------- */

#define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
set_##_name(struct device *dev, \
			 struct device_attribute *attr, \
			 const char *buf, size_t count) \
{ \
	return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
} \
static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name);

DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);

static struct attribute *ad525x_attributes_commands[] = {
	&dev_attr_inc_all.attr,
	&dev_attr_dec_all.attr,
	&dev_attr_inc_all_6db.attr,
	&dev_attr_dec_all_6db.attr,
	NULL
};

static const struct attribute_group ad525x_group_commands = {
	.attrs = ad525x_attributes_commands,
};

__devinit int ad_dpot_add_files(struct device *dev,
		unsigned features, unsigned rdac)
{
	int err = sysfs_create_file(&dev->kobj,
		dpot_attrib_wipers[rdac]);
	if (features & F_CMD_EEP)
		err |= sysfs_create_file(&dev->kobj,
			dpot_attrib_eeprom[rdac]);
	if (features & F_CMD_TOL)
		err |= sysfs_create_file(&dev->kobj,
			dpot_attrib_tolerance[rdac]);
	if (features & F_CMD_OTP) {
		err |= sysfs_create_file(&dev->kobj,
			dpot_attrib_otp_en[rdac]);
		err |= sysfs_create_file(&dev->kobj,
			dpot_attrib_otp[rdac]);
	}

	if (err)
		dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
			rdac);

	return err;
}

inline void ad_dpot_remove_files(struct device *dev,
		unsigned features, unsigned rdac)
{
	sysfs_remove_file(&dev->kobj,
		dpot_attrib_wipers[rdac]);
	if (features & F_CMD_EEP)
		sysfs_remove_file(&dev->kobj,
			dpot_attrib_eeprom[rdac]);
	if (features & F_CMD_TOL)
		sysfs_remove_file(&dev->kobj,
			dpot_attrib_tolerance[rdac]);
	if (features & F_CMD_OTP) {
		sysfs_remove_file(&dev->kobj,
			dpot_attrib_otp_en[rdac]);
		sysfs_remove_file(&dev->kobj,
			dpot_attrib_otp[rdac]);
	}
}

__devinit int ad_dpot_probe(struct device *dev,
		struct ad_dpot_bus_data *bdata, const struct ad_dpot_id *id)
{

	struct dpot_data *data;
	int i, err = 0;

	data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto exit;
	}

	dev_set_drvdata(dev, data);
	mutex_init(&data->update_lock);

	data->bdata = *bdata;
	data->devid = id->devid;

	data->max_pos = 1 << DPOT_MAX_POS(data->devid);
	data->rdac_mask = data->max_pos - 1;
	data->feat = DPOT_FEAT(data->devid);
	data->uid = DPOT_UID(data->devid);
	data->wipers = DPOT_WIPERS(data->devid);

	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
		if (data->wipers & (1 << i)) {
			err = ad_dpot_add_files(dev, data->feat, i);
			if (err)
				goto exit_remove_files;
			/* power-up midscale */
			if (data->feat & F_RDACS_WONLY)
				data->rdac_cache[i] = data->max_pos / 2;
		}

	if (data->feat & F_CMD_INC)
		err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);

	if (err) {
		dev_err(dev, "failed to register sysfs hooks\n");
		goto exit_free;
	}

	dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
		 id->name, data->max_pos);

	return 0;

exit_remove_files:
	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
		if (data->wipers & (1 << i))
			ad_dpot_remove_files(dev, data->feat, i);

exit_free:
	kfree(data);
	dev_set_drvdata(dev, NULL);
exit:
	dev_err(dev, "failed to create client for %s ID 0x%lX\n",
			id->name, id->devid);
	return err;
}
EXPORT_SYMBOL(ad_dpot_probe);

__devexit int ad_dpot_remove(struct device *dev)
{
	struct dpot_data *data = dev_get_drvdata(dev);
	int i;

	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
		if (data->wipers & (1 << i))
			ad_dpot_remove_files(dev, data->feat, i);

	kfree(data);

	return 0;
}
EXPORT_SYMBOL(ad_dpot_remove);


MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
	      "Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Digital potentiometer driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRIVER_VERSION);