xref: /openbmc/linux/drivers/misc/ad525x_dpot.c (revision d003d772)
1 /*
2  * ad525x_dpot: Driver for the Analog Devices digital potentiometers
3  * Copyright (c) 2009-2010 Analog Devices, Inc.
4  * Author: Michael Hennerich <michael.hennerich@analog.com>
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) 2006-2011 Michael Hennerich <michael.hennerich@analog.com>
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/delay.h>
76 #include <linux/slab.h>
77 
78 #include "ad525x_dpot.h"
79 
80 /*
81  * Client data (each client gets its own)
82  */
83 
84 struct dpot_data {
85 	struct ad_dpot_bus_data	bdata;
86 	struct mutex update_lock;
87 	unsigned int rdac_mask;
88 	unsigned int max_pos;
89 	unsigned long devid;
90 	unsigned int uid;
91 	unsigned int feat;
92 	unsigned int wipers;
93 	u16 rdac_cache[MAX_RDACS];
94 	DECLARE_BITMAP(otp_en_mask, MAX_RDACS);
95 };
96 
97 static inline int dpot_read_d8(struct dpot_data *dpot)
98 {
99 	return dpot->bdata.bops->read_d8(dpot->bdata.client);
100 }
101 
102 static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg)
103 {
104 	return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg);
105 }
106 
107 static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg)
108 {
109 	return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg);
110 }
111 
112 static inline int dpot_write_d8(struct dpot_data *dpot, u8 val)
113 {
114 	return dpot->bdata.bops->write_d8(dpot->bdata.client, val);
115 }
116 
117 static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val)
118 {
119 	return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val);
120 }
121 
122 static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val)
123 {
124 	return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val);
125 }
126 
127 static s32 dpot_read_spi(struct dpot_data *dpot, u8 reg)
128 {
129 	unsigned int ctrl = 0;
130 	int value;
131 
132 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
133 
134 		if (dpot->feat & F_RDACS_WONLY)
135 			return dpot->rdac_cache[reg & DPOT_RDAC_MASK];
136 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
137 			dpot->uid == DPOT_UID(AD5292_ID) ||
138 			dpot->uid == DPOT_UID(AD5293_ID)) {
139 
140 			value = dpot_read_r8d8(dpot,
141 				DPOT_AD5291_READ_RDAC << 2);
142 
143 			if (dpot->uid == DPOT_UID(AD5291_ID))
144 				value = value >> 2;
145 
146 			return value;
147 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
148 			dpot->uid == DPOT_UID(AD5271_ID)) {
149 
150 			value = dpot_read_r8d8(dpot,
151 				DPOT_AD5270_1_2_4_READ_RDAC << 2);
152 
153 			if (value < 0)
154 				return value;
155 
156 			if (dpot->uid == DPOT_UID(AD5271_ID))
157 				value = value >> 2;
158 
159 			return value;
160 		}
161 
162 		ctrl = DPOT_SPI_READ_RDAC;
163 	} else if (reg & DPOT_ADDR_EEPROM) {
164 		ctrl = DPOT_SPI_READ_EEPROM;
165 	}
166 
167 	if (dpot->feat & F_SPI_16BIT)
168 		return dpot_read_r8d8(dpot, ctrl);
169 	else if (dpot->feat & F_SPI_24BIT)
170 		return dpot_read_r8d16(dpot, ctrl);
171 
172 	return -EFAULT;
173 }
174 
175 static s32 dpot_read_i2c(struct dpot_data *dpot, u8 reg)
176 {
177 	int value;
178 	unsigned int ctrl = 0;
179 
180 	switch (dpot->uid) {
181 	case DPOT_UID(AD5246_ID):
182 	case DPOT_UID(AD5247_ID):
183 		return dpot_read_d8(dpot);
184 	case DPOT_UID(AD5245_ID):
185 	case DPOT_UID(AD5241_ID):
186 	case DPOT_UID(AD5242_ID):
187 	case DPOT_UID(AD5243_ID):
188 	case DPOT_UID(AD5248_ID):
189 	case DPOT_UID(AD5280_ID):
190 	case DPOT_UID(AD5282_ID):
191 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
192 			0 : DPOT_AD5282_RDAC_AB;
193 		return dpot_read_r8d8(dpot, ctrl);
194 	case DPOT_UID(AD5170_ID):
195 	case DPOT_UID(AD5171_ID):
196 	case DPOT_UID(AD5273_ID):
197 			return dpot_read_d8(dpot);
198 	case DPOT_UID(AD5172_ID):
199 	case DPOT_UID(AD5173_ID):
200 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
201 			0 : DPOT_AD5172_3_A0;
202 		return dpot_read_r8d8(dpot, ctrl);
203 	case DPOT_UID(AD5272_ID):
204 	case DPOT_UID(AD5274_ID):
205 		dpot_write_r8d8(dpot,
206 				(DPOT_AD5270_1_2_4_READ_RDAC << 2), 0);
207 
208 		value = dpot_read_r8d16(dpot, DPOT_AD5270_1_2_4_RDAC << 2);
209 		if (value < 0)
210 			return value;
211 		/*
212 		 * AD5272/AD5274 returns high byte first, however
213 		 * underling smbus expects low byte first.
214 		 */
215 		value = swab16(value);
216 
217 		if (dpot->uid == DPOT_UID(AD5274_ID))
218 			value = value >> 2;
219 		return value;
220 	default:
221 		if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
222 			return dpot_read_r8d16(dpot, (reg & 0xF8) |
223 					((reg & 0x7) << 1));
224 		else
225 			return dpot_read_r8d8(dpot, reg);
226 	}
227 }
228 
229 static s32 dpot_read(struct dpot_data *dpot, u8 reg)
230 {
231 	if (dpot->feat & F_SPI)
232 		return dpot_read_spi(dpot, reg);
233 	else
234 		return dpot_read_i2c(dpot, reg);
235 }
236 
237 static s32 dpot_write_spi(struct dpot_data *dpot, u8 reg, u16 value)
238 {
239 	unsigned int val = 0;
240 
241 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD | DPOT_ADDR_OTP))) {
242 		if (dpot->feat & F_RDACS_WONLY)
243 			dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value;
244 
245 		if (dpot->feat & F_AD_APPDATA) {
246 			if (dpot->feat & F_SPI_8BIT) {
247 				val = ((reg & DPOT_RDAC_MASK) <<
248 					DPOT_MAX_POS(dpot->devid)) |
249 					value;
250 				return dpot_write_d8(dpot, val);
251 			} else if (dpot->feat & F_SPI_16BIT) {
252 				val = ((reg & DPOT_RDAC_MASK) <<
253 					DPOT_MAX_POS(dpot->devid)) |
254 					value;
255 				return dpot_write_r8d8(dpot, val >> 8,
256 					val & 0xFF);
257 			} else
258 				BUG();
259 		} else {
260 			if (dpot->uid == DPOT_UID(AD5291_ID) ||
261 				dpot->uid == DPOT_UID(AD5292_ID) ||
262 				dpot->uid == DPOT_UID(AD5293_ID)) {
263 
264 				dpot_write_r8d8(dpot, DPOT_AD5291_CTRLREG << 2,
265 						DPOT_AD5291_UNLOCK_CMD);
266 
267 				if (dpot->uid == DPOT_UID(AD5291_ID))
268 					value = value << 2;
269 
270 				return dpot_write_r8d8(dpot,
271 					(DPOT_AD5291_RDAC << 2) |
272 					(value >> 8), value & 0xFF);
273 			} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
274 				dpot->uid == DPOT_UID(AD5271_ID)) {
275 				dpot_write_r8d8(dpot,
276 						DPOT_AD5270_1_2_4_CTRLREG << 2,
277 						DPOT_AD5270_1_2_4_UNLOCK_CMD);
278 
279 				if (dpot->uid == DPOT_UID(AD5271_ID))
280 					value = value << 2;
281 
282 				return dpot_write_r8d8(dpot,
283 					(DPOT_AD5270_1_2_4_RDAC << 2) |
284 					(value >> 8), value & 0xFF);
285 			}
286 			val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK);
287 		}
288 	} else if (reg & DPOT_ADDR_EEPROM) {
289 		val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK);
290 	} else if (reg & DPOT_ADDR_CMD) {
291 		switch (reg) {
292 		case DPOT_DEC_ALL_6DB:
293 			val = DPOT_SPI_DEC_ALL_6DB;
294 			break;
295 		case DPOT_INC_ALL_6DB:
296 			val = DPOT_SPI_INC_ALL_6DB;
297 			break;
298 		case DPOT_DEC_ALL:
299 			val = DPOT_SPI_DEC_ALL;
300 			break;
301 		case DPOT_INC_ALL:
302 			val = DPOT_SPI_INC_ALL;
303 			break;
304 		}
305 	} else if (reg & DPOT_ADDR_OTP) {
306 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
307 			dpot->uid == DPOT_UID(AD5292_ID)) {
308 			return dpot_write_r8d8(dpot,
309 				DPOT_AD5291_STORE_XTPM << 2, 0);
310 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
311 			dpot->uid == DPOT_UID(AD5271_ID)) {
312 			return dpot_write_r8d8(dpot,
313 				DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
314 		}
315 	} else
316 		BUG();
317 
318 	if (dpot->feat & F_SPI_16BIT)
319 		return dpot_write_r8d8(dpot, val, value);
320 	else if (dpot->feat & F_SPI_24BIT)
321 		return dpot_write_r8d16(dpot, val, value);
322 
323 	return -EFAULT;
324 }
325 
326 static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
327 {
328 	/* Only write the instruction byte for certain commands */
329 	unsigned int tmp = 0, ctrl = 0;
330 
331 	switch (dpot->uid) {
332 	case DPOT_UID(AD5246_ID):
333 	case DPOT_UID(AD5247_ID):
334 		return dpot_write_d8(dpot, value);
335 
336 	case DPOT_UID(AD5245_ID):
337 	case DPOT_UID(AD5241_ID):
338 	case DPOT_UID(AD5242_ID):
339 	case DPOT_UID(AD5243_ID):
340 	case DPOT_UID(AD5248_ID):
341 	case DPOT_UID(AD5280_ID):
342 	case DPOT_UID(AD5282_ID):
343 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
344 			0 : DPOT_AD5282_RDAC_AB;
345 		return dpot_write_r8d8(dpot, ctrl, value);
346 	case DPOT_UID(AD5171_ID):
347 	case DPOT_UID(AD5273_ID):
348 		if (reg & DPOT_ADDR_OTP) {
349 			tmp = dpot_read_d8(dpot);
350 			if (tmp >> 6) /* Ready to Program? */
351 				return -EFAULT;
352 			ctrl = DPOT_AD5273_FUSE;
353 		}
354 		return dpot_write_r8d8(dpot, ctrl, value);
355 	case DPOT_UID(AD5172_ID):
356 	case DPOT_UID(AD5173_ID):
357 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
358 			0 : DPOT_AD5172_3_A0;
359 		if (reg & DPOT_ADDR_OTP) {
360 			tmp = dpot_read_r8d16(dpot, ctrl);
361 			if (tmp >> 14) /* Ready to Program? */
362 				return -EFAULT;
363 			ctrl |= DPOT_AD5170_2_3_FUSE;
364 		}
365 		return dpot_write_r8d8(dpot, ctrl, value);
366 	case DPOT_UID(AD5170_ID):
367 		if (reg & DPOT_ADDR_OTP) {
368 			tmp = dpot_read_r8d16(dpot, tmp);
369 			if (tmp >> 14) /* Ready to Program? */
370 				return -EFAULT;
371 			ctrl = DPOT_AD5170_2_3_FUSE;
372 		}
373 		return dpot_write_r8d8(dpot, ctrl, value);
374 	case DPOT_UID(AD5272_ID):
375 	case DPOT_UID(AD5274_ID):
376 		dpot_write_r8d8(dpot, DPOT_AD5270_1_2_4_CTRLREG << 2,
377 				DPOT_AD5270_1_2_4_UNLOCK_CMD);
378 
379 		if (reg & DPOT_ADDR_OTP)
380 			return dpot_write_r8d8(dpot,
381 					DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
382 
383 		if (dpot->uid == DPOT_UID(AD5274_ID))
384 			value = value << 2;
385 
386 		return dpot_write_r8d8(dpot, (DPOT_AD5270_1_2_4_RDAC << 2) |
387 				       (value >> 8), value & 0xFF);
388 	default:
389 		if (reg & DPOT_ADDR_CMD)
390 			return dpot_write_d8(dpot, reg);
391 
392 		if (dpot->max_pos > 256)
393 			return dpot_write_r8d16(dpot, (reg & 0xF8) |
394 						((reg & 0x7) << 1), value);
395 		else
396 			/* All other registers require instruction + data bytes */
397 			return dpot_write_r8d8(dpot, reg, value);
398 	}
399 }
400 
401 static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
402 {
403 	if (dpot->feat & F_SPI)
404 		return dpot_write_spi(dpot, reg, value);
405 	else
406 		return dpot_write_i2c(dpot, reg, value);
407 }
408 
409 /* sysfs functions */
410 
411 static ssize_t sysfs_show_reg(struct device *dev,
412 			      struct device_attribute *attr,
413 			      char *buf, u32 reg)
414 {
415 	struct dpot_data *data = dev_get_drvdata(dev);
416 	s32 value;
417 
418 	if (reg & DPOT_ADDR_OTP_EN)
419 		return sprintf(buf, "%s\n",
420 			test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask) ?
421 			"enabled" : "disabled");
422 
423 
424 	mutex_lock(&data->update_lock);
425 	value = dpot_read(data, reg);
426 	mutex_unlock(&data->update_lock);
427 
428 	if (value < 0)
429 		return -EINVAL;
430 	/*
431 	 * Let someone else deal with converting this ...
432 	 * the tolerance is a two-byte value where the MSB
433 	 * is a sign + integer value, and the LSB is a
434 	 * decimal value.  See page 18 of the AD5258
435 	 * datasheet (Rev. A) for more details.
436 	 */
437 
438 	if (reg & DPOT_REG_TOL)
439 		return sprintf(buf, "0x%04x\n", value & 0xFFFF);
440 	else
441 		return sprintf(buf, "%u\n", value & data->rdac_mask);
442 }
443 
444 static ssize_t sysfs_set_reg(struct device *dev,
445 			     struct device_attribute *attr,
446 			     const char *buf, size_t count, u32 reg)
447 {
448 	struct dpot_data *data = dev_get_drvdata(dev);
449 	unsigned long value;
450 	int err;
451 
452 	if (reg & DPOT_ADDR_OTP_EN) {
453 		if (sysfs_streq(buf, "enabled"))
454 			set_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
455 		else
456 			clear_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
457 
458 		return count;
459 	}
460 
461 	if ((reg & DPOT_ADDR_OTP) &&
462 		!test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask))
463 		return -EPERM;
464 
465 	err = kstrtoul(buf, 10, &value);
466 	if (err)
467 		return err;
468 
469 	if (value > data->rdac_mask)
470 		value = data->rdac_mask;
471 
472 	mutex_lock(&data->update_lock);
473 	dpot_write(data, reg, value);
474 	if (reg & DPOT_ADDR_EEPROM)
475 		msleep(26);	/* Sleep while the EEPROM updates */
476 	else if (reg & DPOT_ADDR_OTP)
477 		msleep(400);	/* Sleep while the OTP updates */
478 	mutex_unlock(&data->update_lock);
479 
480 	return count;
481 }
482 
483 static ssize_t sysfs_do_cmd(struct device *dev,
484 			    struct device_attribute *attr,
485 			    const char *buf, size_t count, u32 reg)
486 {
487 	struct dpot_data *data = dev_get_drvdata(dev);
488 
489 	mutex_lock(&data->update_lock);
490 	dpot_write(data, reg, 0);
491 	mutex_unlock(&data->update_lock);
492 
493 	return count;
494 }
495 
496 /* ------------------------------------------------------------------------- */
497 
498 #define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
499 show_##_name(struct device *dev, \
500 			  struct device_attribute *attr, char *buf) \
501 { \
502 	return sysfs_show_reg(dev, attr, buf, _reg); \
503 }
504 
505 #define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
506 set_##_name(struct device *dev, \
507 			 struct device_attribute *attr, \
508 			 const char *buf, size_t count) \
509 { \
510 	return sysfs_set_reg(dev, attr, buf, count, _reg); \
511 }
512 
513 #define DPOT_DEVICE_SHOW_SET(name, reg) \
514 DPOT_DEVICE_SHOW(name, reg) \
515 DPOT_DEVICE_SET(name, reg) \
516 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name)
517 
518 #define DPOT_DEVICE_SHOW_ONLY(name, reg) \
519 DPOT_DEVICE_SHOW(name, reg) \
520 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL)
521 
522 DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
523 DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
524 DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
525 DPOT_DEVICE_SHOW_SET(otp0, DPOT_ADDR_OTP | DPOT_RDAC0);
526 DPOT_DEVICE_SHOW_SET(otp0en, DPOT_ADDR_OTP_EN | DPOT_RDAC0);
527 
528 DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
529 DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
530 DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
531 DPOT_DEVICE_SHOW_SET(otp1, DPOT_ADDR_OTP | DPOT_RDAC1);
532 DPOT_DEVICE_SHOW_SET(otp1en, DPOT_ADDR_OTP_EN | DPOT_RDAC1);
533 
534 DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
535 DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
536 DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
537 DPOT_DEVICE_SHOW_SET(otp2, DPOT_ADDR_OTP | DPOT_RDAC2);
538 DPOT_DEVICE_SHOW_SET(otp2en, DPOT_ADDR_OTP_EN | DPOT_RDAC2);
539 
540 DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
541 DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
542 DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
543 DPOT_DEVICE_SHOW_SET(otp3, DPOT_ADDR_OTP | DPOT_RDAC3);
544 DPOT_DEVICE_SHOW_SET(otp3en, DPOT_ADDR_OTP_EN | DPOT_RDAC3);
545 
546 DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
547 DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
548 DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
549 DPOT_DEVICE_SHOW_SET(otp4, DPOT_ADDR_OTP | DPOT_RDAC4);
550 DPOT_DEVICE_SHOW_SET(otp4en, DPOT_ADDR_OTP_EN | DPOT_RDAC4);
551 
552 DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
553 DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
554 DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
555 DPOT_DEVICE_SHOW_SET(otp5, DPOT_ADDR_OTP | DPOT_RDAC5);
556 DPOT_DEVICE_SHOW_SET(otp5en, DPOT_ADDR_OTP_EN | DPOT_RDAC5);
557 
558 static const struct attribute *dpot_attrib_wipers[] = {
559 	&dev_attr_rdac0.attr,
560 	&dev_attr_rdac1.attr,
561 	&dev_attr_rdac2.attr,
562 	&dev_attr_rdac3.attr,
563 	&dev_attr_rdac4.attr,
564 	&dev_attr_rdac5.attr,
565 	NULL
566 };
567 
568 static const struct attribute *dpot_attrib_eeprom[] = {
569 	&dev_attr_eeprom0.attr,
570 	&dev_attr_eeprom1.attr,
571 	&dev_attr_eeprom2.attr,
572 	&dev_attr_eeprom3.attr,
573 	&dev_attr_eeprom4.attr,
574 	&dev_attr_eeprom5.attr,
575 	NULL
576 };
577 
578 static const struct attribute *dpot_attrib_otp[] = {
579 	&dev_attr_otp0.attr,
580 	&dev_attr_otp1.attr,
581 	&dev_attr_otp2.attr,
582 	&dev_attr_otp3.attr,
583 	&dev_attr_otp4.attr,
584 	&dev_attr_otp5.attr,
585 	NULL
586 };
587 
588 static const struct attribute *dpot_attrib_otp_en[] = {
589 	&dev_attr_otp0en.attr,
590 	&dev_attr_otp1en.attr,
591 	&dev_attr_otp2en.attr,
592 	&dev_attr_otp3en.attr,
593 	&dev_attr_otp4en.attr,
594 	&dev_attr_otp5en.attr,
595 	NULL
596 };
597 
598 static const struct attribute *dpot_attrib_tolerance[] = {
599 	&dev_attr_tolerance0.attr,
600 	&dev_attr_tolerance1.attr,
601 	&dev_attr_tolerance2.attr,
602 	&dev_attr_tolerance3.attr,
603 	&dev_attr_tolerance4.attr,
604 	&dev_attr_tolerance5.attr,
605 	NULL
606 };
607 
608 /* ------------------------------------------------------------------------- */
609 
610 #define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
611 set_##_name(struct device *dev, \
612 			 struct device_attribute *attr, \
613 			 const char *buf, size_t count) \
614 { \
615 	return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
616 } \
617 static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name)
618 
619 DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
620 DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
621 DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
622 DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);
623 
624 static struct attribute *ad525x_attributes_commands[] = {
625 	&dev_attr_inc_all.attr,
626 	&dev_attr_dec_all.attr,
627 	&dev_attr_inc_all_6db.attr,
628 	&dev_attr_dec_all_6db.attr,
629 	NULL
630 };
631 
632 static const struct attribute_group ad525x_group_commands = {
633 	.attrs = ad525x_attributes_commands,
634 };
635 
636 static int ad_dpot_add_files(struct device *dev,
637 		unsigned int features, unsigned int rdac)
638 {
639 	int err = sysfs_create_file(&dev->kobj,
640 		dpot_attrib_wipers[rdac]);
641 	if (features & F_CMD_EEP)
642 		err |= sysfs_create_file(&dev->kobj,
643 			dpot_attrib_eeprom[rdac]);
644 	if (features & F_CMD_TOL)
645 		err |= sysfs_create_file(&dev->kobj,
646 			dpot_attrib_tolerance[rdac]);
647 	if (features & F_CMD_OTP) {
648 		err |= sysfs_create_file(&dev->kobj,
649 			dpot_attrib_otp_en[rdac]);
650 		err |= sysfs_create_file(&dev->kobj,
651 			dpot_attrib_otp[rdac]);
652 	}
653 
654 	if (err)
655 		dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
656 			rdac);
657 
658 	return err;
659 }
660 
661 static inline void ad_dpot_remove_files(struct device *dev,
662 		unsigned int features, unsigned int rdac)
663 {
664 	sysfs_remove_file(&dev->kobj,
665 		dpot_attrib_wipers[rdac]);
666 	if (features & F_CMD_EEP)
667 		sysfs_remove_file(&dev->kobj,
668 			dpot_attrib_eeprom[rdac]);
669 	if (features & F_CMD_TOL)
670 		sysfs_remove_file(&dev->kobj,
671 			dpot_attrib_tolerance[rdac]);
672 	if (features & F_CMD_OTP) {
673 		sysfs_remove_file(&dev->kobj,
674 			dpot_attrib_otp_en[rdac]);
675 		sysfs_remove_file(&dev->kobj,
676 			dpot_attrib_otp[rdac]);
677 	}
678 }
679 
680 int ad_dpot_probe(struct device *dev,
681 		struct ad_dpot_bus_data *bdata, unsigned long devid,
682 			    const char *name)
683 {
684 
685 	struct dpot_data *data;
686 	int i, err = 0;
687 
688 	data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
689 	if (!data) {
690 		err = -ENOMEM;
691 		goto exit;
692 	}
693 
694 	dev_set_drvdata(dev, data);
695 	mutex_init(&data->update_lock);
696 
697 	data->bdata = *bdata;
698 	data->devid = devid;
699 
700 	data->max_pos = 1 << DPOT_MAX_POS(devid);
701 	data->rdac_mask = data->max_pos - 1;
702 	data->feat = DPOT_FEAT(devid);
703 	data->uid = DPOT_UID(devid);
704 	data->wipers = DPOT_WIPERS(devid);
705 
706 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
707 		if (data->wipers & (1 << i)) {
708 			err = ad_dpot_add_files(dev, data->feat, i);
709 			if (err)
710 				goto exit_remove_files;
711 			/* power-up midscale */
712 			if (data->feat & F_RDACS_WONLY)
713 				data->rdac_cache[i] = data->max_pos / 2;
714 		}
715 
716 	if (data->feat & F_CMD_INC)
717 		err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);
718 
719 	if (err) {
720 		dev_err(dev, "failed to register sysfs hooks\n");
721 		goto exit_free;
722 	}
723 
724 	dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
725 		 name, data->max_pos);
726 
727 	return 0;
728 
729 exit_remove_files:
730 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
731 		if (data->wipers & (1 << i))
732 			ad_dpot_remove_files(dev, data->feat, i);
733 
734 exit_free:
735 	kfree(data);
736 	dev_set_drvdata(dev, NULL);
737 exit:
738 	dev_err(dev, "failed to create client for %s ID 0x%lX\n",
739 		name, devid);
740 	return err;
741 }
742 EXPORT_SYMBOL(ad_dpot_probe);
743 
744 int ad_dpot_remove(struct device *dev)
745 {
746 	struct dpot_data *data = dev_get_drvdata(dev);
747 	int i;
748 
749 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
750 		if (data->wipers & (1 << i))
751 			ad_dpot_remove_files(dev, data->feat, i);
752 
753 	kfree(data);
754 
755 	return 0;
756 }
757 EXPORT_SYMBOL(ad_dpot_remove);
758 
759 
760 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
761 	      "Michael Hennerich <michael.hennerich@analog.com>");
762 MODULE_DESCRIPTION("Digital potentiometer driver");
763 MODULE_LICENSE("GPL");
764