xref: /openbmc/linux/drivers/misc/ad525x_dpot.c (revision 565d76cb)
1 /*
2  * ad525x_dpot: Driver for the Analog Devices digital potentiometers
3  * Copyright (c) 2009-2010 Analog Devices, Inc.
4  * Author: Michael Hennerich <hennerich@blackfin.uclinux.org>
5  *
6  * DEVID		#Wipers		#Positions 	Resistor Options (kOhm)
7  * AD5258		1		64		1, 10, 50, 100
8  * AD5259		1		256		5, 10, 50, 100
9  * AD5251		2		64		1, 10, 50, 100
10  * AD5252		2		256		1, 10, 50, 100
11  * AD5255		3		512		25, 250
12  * AD5253		4		64		1, 10, 50, 100
13  * AD5254		4		256		1, 10, 50, 100
14  * AD5160		1		256		5, 10, 50, 100
15  * AD5161		1		256		5, 10, 50, 100
16  * AD5162		2		256		2.5, 10, 50, 100
17  * AD5165		1		256		100
18  * AD5200		1		256		10, 50
19  * AD5201		1		33		10, 50
20  * AD5203		4		64		10, 100
21  * AD5204		4		256		10, 50, 100
22  * AD5206		6		256		10, 50, 100
23  * AD5207		2		256		10, 50, 100
24  * AD5231		1		1024		10, 50, 100
25  * AD5232		2		256		10, 50, 100
26  * AD5233		4		64		10, 50, 100
27  * AD5235		2		1024		25, 250
28  * AD5260		1		256		20, 50, 200
29  * AD5262		2		256		20, 50, 200
30  * AD5263		4		256		20, 50, 200
31  * AD5290		1		256		10, 50, 100
32  * AD5291		1		256		20, 50, 100  (20-TP)
33  * AD5292		1		1024		20, 50, 100  (20-TP)
34  * AD5293		1		1024		20, 50, 100
35  * AD7376		1		128		10, 50, 100, 1M
36  * AD8400		1		256		1, 10, 50, 100
37  * AD8402		2		256		1, 10, 50, 100
38  * AD8403		4		256		1, 10, 50, 100
39  * ADN2850		3		512		25, 250
40  * AD5241		1		256		10, 100, 1M
41  * AD5246		1		128		5, 10, 50, 100
42  * AD5247		1		128		5, 10, 50, 100
43  * AD5245		1		256		5, 10, 50, 100
44  * AD5243		2		256		2.5, 10, 50, 100
45  * AD5248		2		256		2.5, 10, 50, 100
46  * AD5242		2		256		20, 50, 200
47  * AD5280		1		256		20, 50, 200
48  * AD5282		2		256		20, 50, 200
49  * ADN2860		3		512		25, 250
50  * AD5273		1		64		1, 10, 50, 100 (OTP)
51  * AD5171		1		64		5, 10, 50, 100 (OTP)
52  * AD5170		1		256		2.5, 10, 50, 100 (OTP)
53  * AD5172		2		256		2.5, 10, 50, 100 (OTP)
54  * AD5173		2		256		2.5, 10, 50, 100 (OTP)
55  * AD5270		1		1024		20, 50, 100 (50-TP)
56  * AD5271		1		256		20, 50, 100 (50-TP)
57  * AD5272		1		1024		20, 50, 100 (50-TP)
58  * AD5274		1		256		20, 50, 100 (50-TP)
59  *
60  * See Documentation/misc-devices/ad525x_dpot.txt for more info.
61  *
62  * derived from ad5258.c
63  * Copyright (c) 2009 Cyber Switching, Inc.
64  * Author: Chris Verges <chrisv@cyberswitching.com>
65  *
66  * derived from ad5252.c
67  * Copyright (c) 2006 Michael Hennerich <hennerich@blackfin.uclinux.org>
68  *
69  * Licensed under the GPL-2 or later.
70  */
71 
72 #include <linux/module.h>
73 #include <linux/device.h>
74 #include <linux/kernel.h>
75 #include <linux/init.h>
76 #include <linux/delay.h>
77 #include <linux/slab.h>
78 
79 #define DRIVER_VERSION			"0.2"
80 
81 #include "ad525x_dpot.h"
82 
83 /*
84  * Client data (each client gets its own)
85  */
86 
87 struct dpot_data {
88 	struct ad_dpot_bus_data	bdata;
89 	struct mutex update_lock;
90 	unsigned rdac_mask;
91 	unsigned max_pos;
92 	unsigned long devid;
93 	unsigned uid;
94 	unsigned feat;
95 	unsigned wipers;
96 	u16 rdac_cache[MAX_RDACS];
97 	DECLARE_BITMAP(otp_en_mask, MAX_RDACS);
98 };
99 
100 static inline int dpot_read_d8(struct dpot_data *dpot)
101 {
102 	return dpot->bdata.bops->read_d8(dpot->bdata.client);
103 }
104 
105 static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg)
106 {
107 	return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg);
108 }
109 
110 static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg)
111 {
112 	return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg);
113 }
114 
115 static inline int dpot_write_d8(struct dpot_data *dpot, u8 val)
116 {
117 	return dpot->bdata.bops->write_d8(dpot->bdata.client, val);
118 }
119 
120 static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val)
121 {
122 	return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val);
123 }
124 
125 static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val)
126 {
127 	return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val);
128 }
129 
130 static s32 dpot_read_spi(struct dpot_data *dpot, u8 reg)
131 {
132 	unsigned ctrl = 0;
133 	int value;
134 
135 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
136 
137 		if (dpot->feat & F_RDACS_WONLY)
138 			return dpot->rdac_cache[reg & DPOT_RDAC_MASK];
139 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
140 			dpot->uid == DPOT_UID(AD5292_ID) ||
141 			dpot->uid == DPOT_UID(AD5293_ID)) {
142 
143 			value = dpot_read_r8d8(dpot,
144 				DPOT_AD5291_READ_RDAC << 2);
145 
146 			if (dpot->uid == DPOT_UID(AD5291_ID))
147 				value = value >> 2;
148 
149 			return value;
150 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
151 			dpot->uid == DPOT_UID(AD5271_ID)) {
152 
153 			value = dpot_read_r8d8(dpot,
154 				DPOT_AD5270_1_2_4_READ_RDAC << 2);
155 
156 			if (value < 0)
157 				return value;
158 
159 			if (dpot->uid == DPOT_UID(AD5271_ID))
160 				value = value >> 2;
161 
162 			return value;
163 		}
164 
165 		ctrl = DPOT_SPI_READ_RDAC;
166 	} else if (reg & DPOT_ADDR_EEPROM) {
167 		ctrl = DPOT_SPI_READ_EEPROM;
168 	}
169 
170 	if (dpot->feat & F_SPI_16BIT)
171 		return dpot_read_r8d8(dpot, ctrl);
172 	else if (dpot->feat & F_SPI_24BIT)
173 		return dpot_read_r8d16(dpot, ctrl);
174 
175 	return -EFAULT;
176 }
177 
178 static s32 dpot_read_i2c(struct dpot_data *dpot, u8 reg)
179 {
180 	int value;
181 	unsigned ctrl = 0;
182 	switch (dpot->uid) {
183 	case DPOT_UID(AD5246_ID):
184 	case DPOT_UID(AD5247_ID):
185 		return dpot_read_d8(dpot);
186 	case DPOT_UID(AD5245_ID):
187 	case DPOT_UID(AD5241_ID):
188 	case DPOT_UID(AD5242_ID):
189 	case DPOT_UID(AD5243_ID):
190 	case DPOT_UID(AD5248_ID):
191 	case DPOT_UID(AD5280_ID):
192 	case DPOT_UID(AD5282_ID):
193 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
194 			0 : DPOT_AD5282_RDAC_AB;
195 		return dpot_read_r8d8(dpot, ctrl);
196 	case DPOT_UID(AD5170_ID):
197 	case DPOT_UID(AD5171_ID):
198 	case DPOT_UID(AD5273_ID):
199 			return dpot_read_d8(dpot);
200 	case DPOT_UID(AD5172_ID):
201 	case DPOT_UID(AD5173_ID):
202 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
203 			0 : DPOT_AD5172_3_A0;
204 		return dpot_read_r8d8(dpot, ctrl);
205 	case DPOT_UID(AD5272_ID):
206 	case DPOT_UID(AD5274_ID):
207 			dpot_write_r8d8(dpot,
208 				(DPOT_AD5270_1_2_4_READ_RDAC << 2), 0);
209 
210 			value = dpot_read_r8d16(dpot,
211 				DPOT_AD5270_1_2_4_RDAC << 2);
212 
213 			if (value < 0)
214 				return value;
215 			/*
216 			 * AD5272/AD5274 returns high byte first, however
217 			 * underling smbus expects low byte first.
218 			 */
219 			value = swab16(value);
220 
221 			if (dpot->uid == DPOT_UID(AD5271_ID))
222 				value = value >> 2;
223 		return value;
224 	default:
225 		if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
226 			return dpot_read_r8d16(dpot, (reg & 0xF8) |
227 					((reg & 0x7) << 1));
228 		else
229 			return dpot_read_r8d8(dpot, reg);
230 	}
231 }
232 
233 static s32 dpot_read(struct dpot_data *dpot, u8 reg)
234 {
235 	if (dpot->feat & F_SPI)
236 		return dpot_read_spi(dpot, reg);
237 	else
238 		return dpot_read_i2c(dpot, reg);
239 }
240 
241 static s32 dpot_write_spi(struct dpot_data *dpot, u8 reg, u16 value)
242 {
243 	unsigned val = 0;
244 
245 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD | DPOT_ADDR_OTP))) {
246 		if (dpot->feat & F_RDACS_WONLY)
247 			dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value;
248 
249 		if (dpot->feat & F_AD_APPDATA) {
250 			if (dpot->feat & F_SPI_8BIT) {
251 				val = ((reg & DPOT_RDAC_MASK) <<
252 					DPOT_MAX_POS(dpot->devid)) |
253 					value;
254 				return dpot_write_d8(dpot, val);
255 			} else if (dpot->feat & F_SPI_16BIT) {
256 				val = ((reg & DPOT_RDAC_MASK) <<
257 					DPOT_MAX_POS(dpot->devid)) |
258 					value;
259 				return dpot_write_r8d8(dpot, val >> 8,
260 					val & 0xFF);
261 			} else
262 				BUG();
263 		} else {
264 			if (dpot->uid == DPOT_UID(AD5291_ID) ||
265 				dpot->uid == DPOT_UID(AD5292_ID) ||
266 				dpot->uid == DPOT_UID(AD5293_ID)) {
267 
268 				dpot_write_r8d8(dpot, DPOT_AD5291_CTRLREG << 2,
269 						DPOT_AD5291_UNLOCK_CMD);
270 
271 				if (dpot->uid == DPOT_UID(AD5291_ID))
272 					value = value << 2;
273 
274 				return dpot_write_r8d8(dpot,
275 					(DPOT_AD5291_RDAC << 2) |
276 					(value >> 8), value & 0xFF);
277 			} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
278 				dpot->uid == DPOT_UID(AD5271_ID)) {
279 				dpot_write_r8d8(dpot,
280 						DPOT_AD5270_1_2_4_CTRLREG << 2,
281 						DPOT_AD5270_1_2_4_UNLOCK_CMD);
282 
283 				if (dpot->uid == DPOT_UID(AD5271_ID))
284 					value = value << 2;
285 
286 				return dpot_write_r8d8(dpot,
287 					(DPOT_AD5270_1_2_4_RDAC << 2) |
288 					(value >> 8), value & 0xFF);
289 			}
290 			val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK);
291 		}
292 	} else if (reg & DPOT_ADDR_EEPROM) {
293 		val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK);
294 	} else if (reg & DPOT_ADDR_CMD) {
295 		switch (reg) {
296 		case DPOT_DEC_ALL_6DB:
297 			val = DPOT_SPI_DEC_ALL_6DB;
298 			break;
299 		case DPOT_INC_ALL_6DB:
300 			val = DPOT_SPI_INC_ALL_6DB;
301 			break;
302 		case DPOT_DEC_ALL:
303 			val = DPOT_SPI_DEC_ALL;
304 			break;
305 		case DPOT_INC_ALL:
306 			val = DPOT_SPI_INC_ALL;
307 			break;
308 		}
309 	} else if (reg & DPOT_ADDR_OTP) {
310 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
311 			dpot->uid == DPOT_UID(AD5292_ID)) {
312 			return dpot_write_r8d8(dpot,
313 				DPOT_AD5291_STORE_XTPM << 2, 0);
314 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
315 			dpot->uid == DPOT_UID(AD5271_ID)) {
316 			return dpot_write_r8d8(dpot,
317 				DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
318 		}
319 	} else
320 		BUG();
321 
322 	if (dpot->feat & F_SPI_16BIT)
323 		return dpot_write_r8d8(dpot, val, value);
324 	else if (dpot->feat & F_SPI_24BIT)
325 		return dpot_write_r8d16(dpot, val, value);
326 
327 	return -EFAULT;
328 }
329 
330 static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
331 {
332 	/* Only write the instruction byte for certain commands */
333 	unsigned tmp = 0, ctrl = 0;
334 
335 	switch (dpot->uid) {
336 	case DPOT_UID(AD5246_ID):
337 	case DPOT_UID(AD5247_ID):
338 		return dpot_write_d8(dpot, value);
339 		break;
340 
341 	case DPOT_UID(AD5245_ID):
342 	case DPOT_UID(AD5241_ID):
343 	case DPOT_UID(AD5242_ID):
344 	case DPOT_UID(AD5243_ID):
345 	case DPOT_UID(AD5248_ID):
346 	case DPOT_UID(AD5280_ID):
347 	case DPOT_UID(AD5282_ID):
348 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
349 			0 : DPOT_AD5282_RDAC_AB;
350 		return dpot_write_r8d8(dpot, ctrl, value);
351 		break;
352 	case DPOT_UID(AD5171_ID):
353 	case DPOT_UID(AD5273_ID):
354 		if (reg & DPOT_ADDR_OTP) {
355 			tmp = dpot_read_d8(dpot);
356 			if (tmp >> 6) /* Ready to Program? */
357 				return -EFAULT;
358 			ctrl = DPOT_AD5273_FUSE;
359 		}
360 		return dpot_write_r8d8(dpot, ctrl, value);
361 		break;
362 	case DPOT_UID(AD5172_ID):
363 	case DPOT_UID(AD5173_ID):
364 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
365 			0 : DPOT_AD5172_3_A0;
366 		if (reg & DPOT_ADDR_OTP) {
367 			tmp = dpot_read_r8d16(dpot, ctrl);
368 			if (tmp >> 14) /* Ready to Program? */
369 				return -EFAULT;
370 			ctrl |= DPOT_AD5170_2_3_FUSE;
371 		}
372 		return dpot_write_r8d8(dpot, ctrl, value);
373 		break;
374 	case DPOT_UID(AD5170_ID):
375 		if (reg & DPOT_ADDR_OTP) {
376 			tmp = dpot_read_r8d16(dpot, tmp);
377 			if (tmp >> 14) /* Ready to Program? */
378 				return -EFAULT;
379 			ctrl = DPOT_AD5170_2_3_FUSE;
380 		}
381 		return dpot_write_r8d8(dpot, ctrl, value);
382 		break;
383 	case DPOT_UID(AD5272_ID):
384 	case DPOT_UID(AD5274_ID):
385 		dpot_write_r8d8(dpot, DPOT_AD5270_1_2_4_CTRLREG << 2,
386 				DPOT_AD5270_1_2_4_UNLOCK_CMD);
387 
388 		if (reg & DPOT_ADDR_OTP)
389 			return dpot_write_r8d8(dpot,
390 					DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
391 
392 		if (dpot->uid == DPOT_UID(AD5274_ID))
393 			value = value << 2;
394 
395 		return dpot_write_r8d8(dpot, (DPOT_AD5270_1_2_4_RDAC << 2) |
396 				       (value >> 8), value & 0xFF);
397 		break;
398 	default:
399 		if (reg & DPOT_ADDR_CMD)
400 			return dpot_write_d8(dpot, reg);
401 
402 		if (dpot->max_pos > 256)
403 			return dpot_write_r8d16(dpot, (reg & 0xF8) |
404 						((reg & 0x7) << 1), value);
405 		else
406 			/* All other registers require instruction + data bytes */
407 			return dpot_write_r8d8(dpot, reg, value);
408 	}
409 }
410 
411 static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
412 {
413 	if (dpot->feat & F_SPI)
414 		return dpot_write_spi(dpot, reg, value);
415 	else
416 		return dpot_write_i2c(dpot, reg, value);
417 }
418 
419 /* sysfs functions */
420 
421 static ssize_t sysfs_show_reg(struct device *dev,
422 			      struct device_attribute *attr,
423 			      char *buf, u32 reg)
424 {
425 	struct dpot_data *data = dev_get_drvdata(dev);
426 	s32 value;
427 
428 	if (reg & DPOT_ADDR_OTP_EN)
429 		return sprintf(buf, "%s\n",
430 			test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask) ?
431 			"enabled" : "disabled");
432 
433 
434 	mutex_lock(&data->update_lock);
435 	value = dpot_read(data, reg);
436 	mutex_unlock(&data->update_lock);
437 
438 	if (value < 0)
439 		return -EINVAL;
440 	/*
441 	 * Let someone else deal with converting this ...
442 	 * the tolerance is a two-byte value where the MSB
443 	 * is a sign + integer value, and the LSB is a
444 	 * decimal value.  See page 18 of the AD5258
445 	 * datasheet (Rev. A) for more details.
446 	 */
447 
448 	if (reg & DPOT_REG_TOL)
449 		return sprintf(buf, "0x%04x\n", value & 0xFFFF);
450 	else
451 		return sprintf(buf, "%u\n", value & data->rdac_mask);
452 }
453 
454 static ssize_t sysfs_set_reg(struct device *dev,
455 			     struct device_attribute *attr,
456 			     const char *buf, size_t count, u32 reg)
457 {
458 	struct dpot_data *data = dev_get_drvdata(dev);
459 	unsigned long value;
460 	int err;
461 
462 	if (reg & DPOT_ADDR_OTP_EN) {
463 		if (!strncmp(buf, "enabled", sizeof("enabled")))
464 			set_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
465 		else
466 			clear_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
467 
468 		return count;
469 	}
470 
471 	if ((reg & DPOT_ADDR_OTP) &&
472 		!test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask))
473 		return -EPERM;
474 
475 	err = strict_strtoul(buf, 10, &value);
476 	if (err)
477 		return err;
478 
479 	if (value > data->rdac_mask)
480 		value = data->rdac_mask;
481 
482 	mutex_lock(&data->update_lock);
483 	dpot_write(data, reg, value);
484 	if (reg & DPOT_ADDR_EEPROM)
485 		msleep(26);	/* Sleep while the EEPROM updates */
486 	else if (reg & DPOT_ADDR_OTP)
487 		msleep(400);	/* Sleep while the OTP updates */
488 	mutex_unlock(&data->update_lock);
489 
490 	return count;
491 }
492 
493 static ssize_t sysfs_do_cmd(struct device *dev,
494 			    struct device_attribute *attr,
495 			    const char *buf, size_t count, u32 reg)
496 {
497 	struct dpot_data *data = dev_get_drvdata(dev);
498 
499 	mutex_lock(&data->update_lock);
500 	dpot_write(data, reg, 0);
501 	mutex_unlock(&data->update_lock);
502 
503 	return count;
504 }
505 
506 /* ------------------------------------------------------------------------- */
507 
508 #define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
509 show_##_name(struct device *dev, \
510 			  struct device_attribute *attr, char *buf) \
511 { \
512 	return sysfs_show_reg(dev, attr, buf, _reg); \
513 }
514 
515 #define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
516 set_##_name(struct device *dev, \
517 			 struct device_attribute *attr, \
518 			 const char *buf, size_t count) \
519 { \
520 	return sysfs_set_reg(dev, attr, buf, count, _reg); \
521 }
522 
523 #define DPOT_DEVICE_SHOW_SET(name, reg) \
524 DPOT_DEVICE_SHOW(name, reg) \
525 DPOT_DEVICE_SET(name, reg) \
526 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name);
527 
528 #define DPOT_DEVICE_SHOW_ONLY(name, reg) \
529 DPOT_DEVICE_SHOW(name, reg) \
530 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL);
531 
532 DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
533 DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
534 DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
535 DPOT_DEVICE_SHOW_SET(otp0, DPOT_ADDR_OTP | DPOT_RDAC0);
536 DPOT_DEVICE_SHOW_SET(otp0en, DPOT_ADDR_OTP_EN | DPOT_RDAC0);
537 
538 DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
539 DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
540 DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
541 DPOT_DEVICE_SHOW_SET(otp1, DPOT_ADDR_OTP | DPOT_RDAC1);
542 DPOT_DEVICE_SHOW_SET(otp1en, DPOT_ADDR_OTP_EN | DPOT_RDAC1);
543 
544 DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
545 DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
546 DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
547 DPOT_DEVICE_SHOW_SET(otp2, DPOT_ADDR_OTP | DPOT_RDAC2);
548 DPOT_DEVICE_SHOW_SET(otp2en, DPOT_ADDR_OTP_EN | DPOT_RDAC2);
549 
550 DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
551 DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
552 DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
553 DPOT_DEVICE_SHOW_SET(otp3, DPOT_ADDR_OTP | DPOT_RDAC3);
554 DPOT_DEVICE_SHOW_SET(otp3en, DPOT_ADDR_OTP_EN | DPOT_RDAC3);
555 
556 DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
557 DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
558 DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
559 DPOT_DEVICE_SHOW_SET(otp4, DPOT_ADDR_OTP | DPOT_RDAC4);
560 DPOT_DEVICE_SHOW_SET(otp4en, DPOT_ADDR_OTP_EN | DPOT_RDAC4);
561 
562 DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
563 DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
564 DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
565 DPOT_DEVICE_SHOW_SET(otp5, DPOT_ADDR_OTP | DPOT_RDAC5);
566 DPOT_DEVICE_SHOW_SET(otp5en, DPOT_ADDR_OTP_EN | DPOT_RDAC5);
567 
568 static const struct attribute *dpot_attrib_wipers[] = {
569 	&dev_attr_rdac0.attr,
570 	&dev_attr_rdac1.attr,
571 	&dev_attr_rdac2.attr,
572 	&dev_attr_rdac3.attr,
573 	&dev_attr_rdac4.attr,
574 	&dev_attr_rdac5.attr,
575 	NULL
576 };
577 
578 static const struct attribute *dpot_attrib_eeprom[] = {
579 	&dev_attr_eeprom0.attr,
580 	&dev_attr_eeprom1.attr,
581 	&dev_attr_eeprom2.attr,
582 	&dev_attr_eeprom3.attr,
583 	&dev_attr_eeprom4.attr,
584 	&dev_attr_eeprom5.attr,
585 	NULL
586 };
587 
588 static const struct attribute *dpot_attrib_otp[] = {
589 	&dev_attr_otp0.attr,
590 	&dev_attr_otp1.attr,
591 	&dev_attr_otp2.attr,
592 	&dev_attr_otp3.attr,
593 	&dev_attr_otp4.attr,
594 	&dev_attr_otp5.attr,
595 	NULL
596 };
597 
598 static const struct attribute *dpot_attrib_otp_en[] = {
599 	&dev_attr_otp0en.attr,
600 	&dev_attr_otp1en.attr,
601 	&dev_attr_otp2en.attr,
602 	&dev_attr_otp3en.attr,
603 	&dev_attr_otp4en.attr,
604 	&dev_attr_otp5en.attr,
605 	NULL
606 };
607 
608 static const struct attribute *dpot_attrib_tolerance[] = {
609 	&dev_attr_tolerance0.attr,
610 	&dev_attr_tolerance1.attr,
611 	&dev_attr_tolerance2.attr,
612 	&dev_attr_tolerance3.attr,
613 	&dev_attr_tolerance4.attr,
614 	&dev_attr_tolerance5.attr,
615 	NULL
616 };
617 
618 /* ------------------------------------------------------------------------- */
619 
620 #define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
621 set_##_name(struct device *dev, \
622 			 struct device_attribute *attr, \
623 			 const char *buf, size_t count) \
624 { \
625 	return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
626 } \
627 static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name);
628 
629 DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
630 DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
631 DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
632 DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);
633 
634 static struct attribute *ad525x_attributes_commands[] = {
635 	&dev_attr_inc_all.attr,
636 	&dev_attr_dec_all.attr,
637 	&dev_attr_inc_all_6db.attr,
638 	&dev_attr_dec_all_6db.attr,
639 	NULL
640 };
641 
642 static const struct attribute_group ad525x_group_commands = {
643 	.attrs = ad525x_attributes_commands,
644 };
645 
646 __devinit int ad_dpot_add_files(struct device *dev,
647 		unsigned features, unsigned rdac)
648 {
649 	int err = sysfs_create_file(&dev->kobj,
650 		dpot_attrib_wipers[rdac]);
651 	if (features & F_CMD_EEP)
652 		err |= sysfs_create_file(&dev->kobj,
653 			dpot_attrib_eeprom[rdac]);
654 	if (features & F_CMD_TOL)
655 		err |= sysfs_create_file(&dev->kobj,
656 			dpot_attrib_tolerance[rdac]);
657 	if (features & F_CMD_OTP) {
658 		err |= sysfs_create_file(&dev->kobj,
659 			dpot_attrib_otp_en[rdac]);
660 		err |= sysfs_create_file(&dev->kobj,
661 			dpot_attrib_otp[rdac]);
662 	}
663 
664 	if (err)
665 		dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
666 			rdac);
667 
668 	return err;
669 }
670 
671 inline void ad_dpot_remove_files(struct device *dev,
672 		unsigned features, unsigned rdac)
673 {
674 	sysfs_remove_file(&dev->kobj,
675 		dpot_attrib_wipers[rdac]);
676 	if (features & F_CMD_EEP)
677 		sysfs_remove_file(&dev->kobj,
678 			dpot_attrib_eeprom[rdac]);
679 	if (features & F_CMD_TOL)
680 		sysfs_remove_file(&dev->kobj,
681 			dpot_attrib_tolerance[rdac]);
682 	if (features & F_CMD_OTP) {
683 		sysfs_remove_file(&dev->kobj,
684 			dpot_attrib_otp_en[rdac]);
685 		sysfs_remove_file(&dev->kobj,
686 			dpot_attrib_otp[rdac]);
687 	}
688 }
689 
690 __devinit int ad_dpot_probe(struct device *dev,
691 		struct ad_dpot_bus_data *bdata, const struct ad_dpot_id *id)
692 {
693 
694 	struct dpot_data *data;
695 	int i, err = 0;
696 
697 	data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
698 	if (!data) {
699 		err = -ENOMEM;
700 		goto exit;
701 	}
702 
703 	dev_set_drvdata(dev, data);
704 	mutex_init(&data->update_lock);
705 
706 	data->bdata = *bdata;
707 	data->devid = id->devid;
708 
709 	data->max_pos = 1 << DPOT_MAX_POS(data->devid);
710 	data->rdac_mask = data->max_pos - 1;
711 	data->feat = DPOT_FEAT(data->devid);
712 	data->uid = DPOT_UID(data->devid);
713 	data->wipers = DPOT_WIPERS(data->devid);
714 
715 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
716 		if (data->wipers & (1 << i)) {
717 			err = ad_dpot_add_files(dev, data->feat, i);
718 			if (err)
719 				goto exit_remove_files;
720 			/* power-up midscale */
721 			if (data->feat & F_RDACS_WONLY)
722 				data->rdac_cache[i] = data->max_pos / 2;
723 		}
724 
725 	if (data->feat & F_CMD_INC)
726 		err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);
727 
728 	if (err) {
729 		dev_err(dev, "failed to register sysfs hooks\n");
730 		goto exit_free;
731 	}
732 
733 	dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
734 		 id->name, data->max_pos);
735 
736 	return 0;
737 
738 exit_remove_files:
739 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
740 		if (data->wipers & (1 << i))
741 			ad_dpot_remove_files(dev, data->feat, i);
742 
743 exit_free:
744 	kfree(data);
745 	dev_set_drvdata(dev, NULL);
746 exit:
747 	dev_err(dev, "failed to create client for %s ID 0x%lX\n",
748 			id->name, id->devid);
749 	return err;
750 }
751 EXPORT_SYMBOL(ad_dpot_probe);
752 
753 __devexit int ad_dpot_remove(struct device *dev)
754 {
755 	struct dpot_data *data = dev_get_drvdata(dev);
756 	int i;
757 
758 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
759 		if (data->wipers & (1 << i))
760 			ad_dpot_remove_files(dev, data->feat, i);
761 
762 	kfree(data);
763 
764 	return 0;
765 }
766 EXPORT_SYMBOL(ad_dpot_remove);
767 
768 
769 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
770 	      "Michael Hennerich <hennerich@blackfin.uclinux.org>");
771 MODULE_DESCRIPTION("Digital potentiometer driver");
772 MODULE_LICENSE("GPL");
773 MODULE_VERSION(DRIVER_VERSION);
774