xref: /linux/drivers/misc/ad525x_dpot.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ad525x_dpot: Driver for the Analog Devices digital potentiometers
4  * Copyright (c) 2009-2010 Analog Devices, Inc.
5  * Author: Michael Hennerich <michael.hennerich@analog.com>
6  *
7  * DEVID		#Wipers		#Positions	Resistor Options (kOhm)
8  * AD5258		1		64		1, 10, 50, 100
9  * AD5259		1		256		5, 10, 50, 100
10  * AD5251		2		64		1, 10, 50, 100
11  * AD5252		2		256		1, 10, 50, 100
12  * AD5255		3		512		25, 250
13  * AD5253		4		64		1, 10, 50, 100
14  * AD5254		4		256		1, 10, 50, 100
15  * AD5160		1		256		5, 10, 50, 100
16  * AD5161		1		256		5, 10, 50, 100
17  * AD5162		2		256		2.5, 10, 50, 100
18  * AD5165		1		256		100
19  * AD5200		1		256		10, 50
20  * AD5201		1		33		10, 50
21  * AD5203		4		64		10, 100
22  * AD5204		4		256		10, 50, 100
23  * AD5206		6		256		10, 50, 100
24  * AD5207		2		256		10, 50, 100
25  * AD5231		1		1024		10, 50, 100
26  * AD5232		2		256		10, 50, 100
27  * AD5233		4		64		10, 50, 100
28  * AD5235		2		1024		25, 250
29  * AD5260		1		256		20, 50, 200
30  * AD5262		2		256		20, 50, 200
31  * AD5263		4		256		20, 50, 200
32  * AD5290		1		256		10, 50, 100
33  * AD5291		1		256		20, 50, 100  (20-TP)
34  * AD5292		1		1024		20, 50, 100  (20-TP)
35  * AD5293		1		1024		20, 50, 100
36  * AD7376		1		128		10, 50, 100, 1M
37  * AD8400		1		256		1, 10, 50, 100
38  * AD8402		2		256		1, 10, 50, 100
39  * AD8403		4		256		1, 10, 50, 100
40  * ADN2850		3		512		25, 250
41  * AD5241		1		256		10, 100, 1M
42  * AD5246		1		128		5, 10, 50, 100
43  * AD5247		1		128		5, 10, 50, 100
44  * AD5245		1		256		5, 10, 50, 100
45  * AD5243		2		256		2.5, 10, 50, 100
46  * AD5248		2		256		2.5, 10, 50, 100
47  * AD5242		2		256		20, 50, 200
48  * AD5280		1		256		20, 50, 200
49  * AD5282		2		256		20, 50, 200
50  * ADN2860		3		512		25, 250
51  * AD5273		1		64		1, 10, 50, 100 (OTP)
52  * AD5171		1		64		5, 10, 50, 100 (OTP)
53  * AD5170		1		256		2.5, 10, 50, 100 (OTP)
54  * AD5172		2		256		2.5, 10, 50, 100 (OTP)
55  * AD5173		2		256		2.5, 10, 50, 100 (OTP)
56  * AD5270		1		1024		20, 50, 100 (50-TP)
57  * AD5271		1		256		20, 50, 100 (50-TP)
58  * AD5272		1		1024		20, 50, 100 (50-TP)
59  * AD5274		1		256		20, 50, 100 (50-TP)
60  *
61  * See Documentation/misc-devices/ad525x_dpot.rst for more info.
62  *
63  * derived from ad5258.c
64  * Copyright (c) 2009 Cyber Switching, Inc.
65  * Author: Chris Verges <chrisv@cyberswitching.com>
66  *
67  * derived from ad5252.c
68  * Copyright (c) 2006-2011 Michael Hennerich <michael.hennerich@analog.com>
69  */
70 
71 #include <linux/module.h>
72 #include <linux/device.h>
73 #include <linux/kernel.h>
74 #include <linux/delay.h>
75 #include <linux/slab.h>
76 
77 #include "ad525x_dpot.h"
78 
79 /*
80  * Client data (each client gets its own)
81  */
82 
83 struct dpot_data {
84 	struct ad_dpot_bus_data	bdata;
85 	struct mutex update_lock;
86 	unsigned int rdac_mask;
87 	unsigned int max_pos;
88 	unsigned long devid;
89 	unsigned int uid;
90 	unsigned int feat;
91 	unsigned int wipers;
92 	u16 rdac_cache[MAX_RDACS];
93 	DECLARE_BITMAP(otp_en_mask, MAX_RDACS);
94 };
95 
96 static inline int dpot_read_d8(struct dpot_data *dpot)
97 {
98 	return dpot->bdata.bops->read_d8(dpot->bdata.client);
99 }
100 
101 static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg)
102 {
103 	return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg);
104 }
105 
106 static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg)
107 {
108 	return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg);
109 }
110 
111 static inline int dpot_write_d8(struct dpot_data *dpot, u8 val)
112 {
113 	return dpot->bdata.bops->write_d8(dpot->bdata.client, val);
114 }
115 
116 static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val)
117 {
118 	return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val);
119 }
120 
121 static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val)
122 {
123 	return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val);
124 }
125 
126 static s32 dpot_read_spi(struct dpot_data *dpot, u8 reg)
127 {
128 	unsigned int ctrl = 0;
129 	int value;
130 
131 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
132 
133 		if (dpot->feat & F_RDACS_WONLY)
134 			return dpot->rdac_cache[reg & DPOT_RDAC_MASK];
135 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
136 			dpot->uid == DPOT_UID(AD5292_ID) ||
137 			dpot->uid == DPOT_UID(AD5293_ID)) {
138 
139 			value = dpot_read_r8d8(dpot,
140 				DPOT_AD5291_READ_RDAC << 2);
141 
142 			if (dpot->uid == DPOT_UID(AD5291_ID))
143 				value = value >> 2;
144 
145 			return value;
146 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
147 			dpot->uid == DPOT_UID(AD5271_ID)) {
148 
149 			value = dpot_read_r8d8(dpot,
150 				DPOT_AD5270_1_2_4_READ_RDAC << 2);
151 
152 			if (value < 0)
153 				return value;
154 
155 			if (dpot->uid == DPOT_UID(AD5271_ID))
156 				value = value >> 2;
157 
158 			return value;
159 		}
160 
161 		ctrl = DPOT_SPI_READ_RDAC;
162 	} else if (reg & DPOT_ADDR_EEPROM) {
163 		ctrl = DPOT_SPI_READ_EEPROM;
164 	}
165 
166 	if (dpot->feat & F_SPI_16BIT)
167 		return dpot_read_r8d8(dpot, ctrl);
168 	else if (dpot->feat & F_SPI_24BIT)
169 		return dpot_read_r8d16(dpot, ctrl);
170 
171 	return -EFAULT;
172 }
173 
174 static s32 dpot_read_i2c(struct dpot_data *dpot, u8 reg)
175 {
176 	int value;
177 	unsigned int ctrl = 0;
178 
179 	switch (dpot->uid) {
180 	case DPOT_UID(AD5246_ID):
181 	case DPOT_UID(AD5247_ID):
182 		return dpot_read_d8(dpot);
183 	case DPOT_UID(AD5245_ID):
184 	case DPOT_UID(AD5241_ID):
185 	case DPOT_UID(AD5242_ID):
186 	case DPOT_UID(AD5243_ID):
187 	case DPOT_UID(AD5248_ID):
188 	case DPOT_UID(AD5280_ID):
189 	case DPOT_UID(AD5282_ID):
190 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
191 			0 : DPOT_AD5282_RDAC_AB;
192 		return dpot_read_r8d8(dpot, ctrl);
193 	case DPOT_UID(AD5170_ID):
194 	case DPOT_UID(AD5171_ID):
195 	case DPOT_UID(AD5273_ID):
196 			return dpot_read_d8(dpot);
197 	case DPOT_UID(AD5172_ID):
198 	case DPOT_UID(AD5173_ID):
199 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
200 			0 : DPOT_AD5172_3_A0;
201 		return dpot_read_r8d8(dpot, ctrl);
202 	case DPOT_UID(AD5272_ID):
203 	case DPOT_UID(AD5274_ID):
204 		dpot_write_r8d8(dpot,
205 				(DPOT_AD5270_1_2_4_READ_RDAC << 2), 0);
206 
207 		value = dpot_read_r8d16(dpot, DPOT_AD5270_1_2_4_RDAC << 2);
208 		if (value < 0)
209 			return value;
210 		/*
211 		 * AD5272/AD5274 returns high byte first, however
212 		 * underling smbus expects low byte first.
213 		 */
214 		value = swab16(value);
215 
216 		if (dpot->uid == DPOT_UID(AD5274_ID))
217 			value = value >> 2;
218 		return value;
219 	default:
220 		if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
221 			return dpot_read_r8d16(dpot, (reg & 0xF8) |
222 					((reg & 0x7) << 1));
223 		else
224 			return dpot_read_r8d8(dpot, reg);
225 	}
226 }
227 
228 static s32 dpot_read(struct dpot_data *dpot, u8 reg)
229 {
230 	if (dpot->feat & F_SPI)
231 		return dpot_read_spi(dpot, reg);
232 	else
233 		return dpot_read_i2c(dpot, reg);
234 }
235 
236 static s32 dpot_write_spi(struct dpot_data *dpot, u8 reg, u16 value)
237 {
238 	unsigned int val = 0;
239 
240 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD | DPOT_ADDR_OTP))) {
241 		if (dpot->feat & F_RDACS_WONLY)
242 			dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value;
243 
244 		if (dpot->feat & F_AD_APPDATA) {
245 			if (dpot->feat & F_SPI_8BIT) {
246 				val = ((reg & DPOT_RDAC_MASK) <<
247 					DPOT_MAX_POS(dpot->devid)) |
248 					value;
249 				return dpot_write_d8(dpot, val);
250 			} else if (dpot->feat & F_SPI_16BIT) {
251 				val = ((reg & DPOT_RDAC_MASK) <<
252 					DPOT_MAX_POS(dpot->devid)) |
253 					value;
254 				return dpot_write_r8d8(dpot, val >> 8,
255 					val & 0xFF);
256 			} else
257 				BUG();
258 		} else {
259 			if (dpot->uid == DPOT_UID(AD5291_ID) ||
260 				dpot->uid == DPOT_UID(AD5292_ID) ||
261 				dpot->uid == DPOT_UID(AD5293_ID)) {
262 
263 				dpot_write_r8d8(dpot, DPOT_AD5291_CTRLREG << 2,
264 						DPOT_AD5291_UNLOCK_CMD);
265 
266 				if (dpot->uid == DPOT_UID(AD5291_ID))
267 					value = value << 2;
268 
269 				return dpot_write_r8d8(dpot,
270 					(DPOT_AD5291_RDAC << 2) |
271 					(value >> 8), value & 0xFF);
272 			} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
273 				dpot->uid == DPOT_UID(AD5271_ID)) {
274 				dpot_write_r8d8(dpot,
275 						DPOT_AD5270_1_2_4_CTRLREG << 2,
276 						DPOT_AD5270_1_2_4_UNLOCK_CMD);
277 
278 				if (dpot->uid == DPOT_UID(AD5271_ID))
279 					value = value << 2;
280 
281 				return dpot_write_r8d8(dpot,
282 					(DPOT_AD5270_1_2_4_RDAC << 2) |
283 					(value >> 8), value & 0xFF);
284 			}
285 			val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK);
286 		}
287 	} else if (reg & DPOT_ADDR_EEPROM) {
288 		val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK);
289 	} else if (reg & DPOT_ADDR_CMD) {
290 		switch (reg) {
291 		case DPOT_DEC_ALL_6DB:
292 			val = DPOT_SPI_DEC_ALL_6DB;
293 			break;
294 		case DPOT_INC_ALL_6DB:
295 			val = DPOT_SPI_INC_ALL_6DB;
296 			break;
297 		case DPOT_DEC_ALL:
298 			val = DPOT_SPI_DEC_ALL;
299 			break;
300 		case DPOT_INC_ALL:
301 			val = DPOT_SPI_INC_ALL;
302 			break;
303 		}
304 	} else if (reg & DPOT_ADDR_OTP) {
305 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
306 			dpot->uid == DPOT_UID(AD5292_ID)) {
307 			return dpot_write_r8d8(dpot,
308 				DPOT_AD5291_STORE_XTPM << 2, 0);
309 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
310 			dpot->uid == DPOT_UID(AD5271_ID)) {
311 			return dpot_write_r8d8(dpot,
312 				DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
313 		}
314 	} else
315 		BUG();
316 
317 	if (dpot->feat & F_SPI_16BIT)
318 		return dpot_write_r8d8(dpot, val, value);
319 	else if (dpot->feat & F_SPI_24BIT)
320 		return dpot_write_r8d16(dpot, val, value);
321 
322 	return -EFAULT;
323 }
324 
325 static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
326 {
327 	/* Only write the instruction byte for certain commands */
328 	unsigned int tmp = 0, ctrl = 0;
329 
330 	switch (dpot->uid) {
331 	case DPOT_UID(AD5246_ID):
332 	case DPOT_UID(AD5247_ID):
333 		return dpot_write_d8(dpot, value);
334 
335 	case DPOT_UID(AD5245_ID):
336 	case DPOT_UID(AD5241_ID):
337 	case DPOT_UID(AD5242_ID):
338 	case DPOT_UID(AD5243_ID):
339 	case DPOT_UID(AD5248_ID):
340 	case DPOT_UID(AD5280_ID):
341 	case DPOT_UID(AD5282_ID):
342 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
343 			0 : DPOT_AD5282_RDAC_AB;
344 		return dpot_write_r8d8(dpot, ctrl, value);
345 	case DPOT_UID(AD5171_ID):
346 	case DPOT_UID(AD5273_ID):
347 		if (reg & DPOT_ADDR_OTP) {
348 			tmp = dpot_read_d8(dpot);
349 			if (tmp >> 6) /* Ready to Program? */
350 				return -EFAULT;
351 			ctrl = DPOT_AD5273_FUSE;
352 		}
353 		return dpot_write_r8d8(dpot, ctrl, value);
354 	case DPOT_UID(AD5172_ID):
355 	case DPOT_UID(AD5173_ID):
356 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
357 			0 : DPOT_AD5172_3_A0;
358 		if (reg & DPOT_ADDR_OTP) {
359 			tmp = dpot_read_r8d16(dpot, ctrl);
360 			if (tmp >> 14) /* Ready to Program? */
361 				return -EFAULT;
362 			ctrl |= DPOT_AD5170_2_3_FUSE;
363 		}
364 		return dpot_write_r8d8(dpot, ctrl, value);
365 	case DPOT_UID(AD5170_ID):
366 		if (reg & DPOT_ADDR_OTP) {
367 			tmp = dpot_read_r8d16(dpot, tmp);
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 	case DPOT_UID(AD5272_ID):
374 	case DPOT_UID(AD5274_ID):
375 		dpot_write_r8d8(dpot, DPOT_AD5270_1_2_4_CTRLREG << 2,
376 				DPOT_AD5270_1_2_4_UNLOCK_CMD);
377 
378 		if (reg & DPOT_ADDR_OTP)
379 			return dpot_write_r8d8(dpot,
380 					DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
381 
382 		if (dpot->uid == DPOT_UID(AD5274_ID))
383 			value = value << 2;
384 
385 		return dpot_write_r8d8(dpot, (DPOT_AD5270_1_2_4_RDAC << 2) |
386 				       (value >> 8), value & 0xFF);
387 	default:
388 		if (reg & DPOT_ADDR_CMD)
389 			return dpot_write_d8(dpot, reg);
390 
391 		if (dpot->max_pos > 256)
392 			return dpot_write_r8d16(dpot, (reg & 0xF8) |
393 						((reg & 0x7) << 1), value);
394 		else
395 			/* All other registers require instruction + data bytes */
396 			return dpot_write_r8d8(dpot, reg, value);
397 	}
398 }
399 
400 static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
401 {
402 	if (dpot->feat & F_SPI)
403 		return dpot_write_spi(dpot, reg, value);
404 	else
405 		return dpot_write_i2c(dpot, reg, value);
406 }
407 
408 /* sysfs functions */
409 
410 static ssize_t sysfs_show_reg(struct device *dev,
411 			      struct device_attribute *attr,
412 			      char *buf, u32 reg)
413 {
414 	struct dpot_data *data = dev_get_drvdata(dev);
415 	s32 value;
416 
417 	if (reg & DPOT_ADDR_OTP_EN)
418 		return sprintf(buf, "%s\n",
419 			test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask) ?
420 			"enabled" : "disabled");
421 
422 
423 	mutex_lock(&data->update_lock);
424 	value = dpot_read(data, reg);
425 	mutex_unlock(&data->update_lock);
426 
427 	if (value < 0)
428 		return -EINVAL;
429 	/*
430 	 * Let someone else deal with converting this ...
431 	 * the tolerance is a two-byte value where the MSB
432 	 * is a sign + integer value, and the LSB is a
433 	 * decimal value.  See page 18 of the AD5258
434 	 * datasheet (Rev. A) for more details.
435 	 */
436 
437 	if (reg & DPOT_REG_TOL)
438 		return sprintf(buf, "0x%04x\n", value & 0xFFFF);
439 	else
440 		return sprintf(buf, "%u\n", value & data->rdac_mask);
441 }
442 
443 static ssize_t sysfs_set_reg(struct device *dev,
444 			     struct device_attribute *attr,
445 			     const char *buf, size_t count, u32 reg)
446 {
447 	struct dpot_data *data = dev_get_drvdata(dev);
448 	unsigned long value;
449 	int err;
450 
451 	if (reg & DPOT_ADDR_OTP_EN) {
452 		if (sysfs_streq(buf, "enabled"))
453 			set_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
454 		else
455 			clear_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
456 
457 		return count;
458 	}
459 
460 	if ((reg & DPOT_ADDR_OTP) &&
461 		!test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask))
462 		return -EPERM;
463 
464 	err = kstrtoul(buf, 10, &value);
465 	if (err)
466 		return err;
467 
468 	if (value > data->rdac_mask)
469 		value = data->rdac_mask;
470 
471 	mutex_lock(&data->update_lock);
472 	dpot_write(data, reg, value);
473 	if (reg & DPOT_ADDR_EEPROM)
474 		msleep(26);	/* Sleep while the EEPROM updates */
475 	else if (reg & DPOT_ADDR_OTP)
476 		msleep(400);	/* Sleep while the OTP updates */
477 	mutex_unlock(&data->update_lock);
478 
479 	return count;
480 }
481 
482 static ssize_t sysfs_do_cmd(struct device *dev,
483 			    struct device_attribute *attr,
484 			    const char *buf, size_t count, u32 reg)
485 {
486 	struct dpot_data *data = dev_get_drvdata(dev);
487 
488 	mutex_lock(&data->update_lock);
489 	dpot_write(data, reg, 0);
490 	mutex_unlock(&data->update_lock);
491 
492 	return count;
493 }
494 
495 /* ------------------------------------------------------------------------- */
496 
497 #define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
498 show_##_name(struct device *dev, \
499 			  struct device_attribute *attr, char *buf) \
500 { \
501 	return sysfs_show_reg(dev, attr, buf, _reg); \
502 }
503 
504 #define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
505 set_##_name(struct device *dev, \
506 			 struct device_attribute *attr, \
507 			 const char *buf, size_t count) \
508 { \
509 	return sysfs_set_reg(dev, attr, buf, count, _reg); \
510 }
511 
512 #define DPOT_DEVICE_SHOW_SET(name, reg) \
513 DPOT_DEVICE_SHOW(name, reg) \
514 DPOT_DEVICE_SET(name, reg) \
515 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name)
516 
517 #define DPOT_DEVICE_SHOW_ONLY(name, reg) \
518 DPOT_DEVICE_SHOW(name, reg) \
519 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL)
520 
521 DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
522 DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
523 DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
524 DPOT_DEVICE_SHOW_SET(otp0, DPOT_ADDR_OTP | DPOT_RDAC0);
525 DPOT_DEVICE_SHOW_SET(otp0en, DPOT_ADDR_OTP_EN | DPOT_RDAC0);
526 
527 DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
528 DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
529 DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
530 DPOT_DEVICE_SHOW_SET(otp1, DPOT_ADDR_OTP | DPOT_RDAC1);
531 DPOT_DEVICE_SHOW_SET(otp1en, DPOT_ADDR_OTP_EN | DPOT_RDAC1);
532 
533 DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
534 DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
535 DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
536 DPOT_DEVICE_SHOW_SET(otp2, DPOT_ADDR_OTP | DPOT_RDAC2);
537 DPOT_DEVICE_SHOW_SET(otp2en, DPOT_ADDR_OTP_EN | DPOT_RDAC2);
538 
539 DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
540 DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
541 DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
542 DPOT_DEVICE_SHOW_SET(otp3, DPOT_ADDR_OTP | DPOT_RDAC3);
543 DPOT_DEVICE_SHOW_SET(otp3en, DPOT_ADDR_OTP_EN | DPOT_RDAC3);
544 
545 DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
546 DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
547 DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
548 DPOT_DEVICE_SHOW_SET(otp4, DPOT_ADDR_OTP | DPOT_RDAC4);
549 DPOT_DEVICE_SHOW_SET(otp4en, DPOT_ADDR_OTP_EN | DPOT_RDAC4);
550 
551 DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
552 DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
553 DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
554 DPOT_DEVICE_SHOW_SET(otp5, DPOT_ADDR_OTP | DPOT_RDAC5);
555 DPOT_DEVICE_SHOW_SET(otp5en, DPOT_ADDR_OTP_EN | DPOT_RDAC5);
556 
557 static const struct attribute *dpot_attrib_wipers[] = {
558 	&dev_attr_rdac0.attr,
559 	&dev_attr_rdac1.attr,
560 	&dev_attr_rdac2.attr,
561 	&dev_attr_rdac3.attr,
562 	&dev_attr_rdac4.attr,
563 	&dev_attr_rdac5.attr,
564 	NULL
565 };
566 
567 static const struct attribute *dpot_attrib_eeprom[] = {
568 	&dev_attr_eeprom0.attr,
569 	&dev_attr_eeprom1.attr,
570 	&dev_attr_eeprom2.attr,
571 	&dev_attr_eeprom3.attr,
572 	&dev_attr_eeprom4.attr,
573 	&dev_attr_eeprom5.attr,
574 	NULL
575 };
576 
577 static const struct attribute *dpot_attrib_otp[] = {
578 	&dev_attr_otp0.attr,
579 	&dev_attr_otp1.attr,
580 	&dev_attr_otp2.attr,
581 	&dev_attr_otp3.attr,
582 	&dev_attr_otp4.attr,
583 	&dev_attr_otp5.attr,
584 	NULL
585 };
586 
587 static const struct attribute *dpot_attrib_otp_en[] = {
588 	&dev_attr_otp0en.attr,
589 	&dev_attr_otp1en.attr,
590 	&dev_attr_otp2en.attr,
591 	&dev_attr_otp3en.attr,
592 	&dev_attr_otp4en.attr,
593 	&dev_attr_otp5en.attr,
594 	NULL
595 };
596 
597 static const struct attribute *dpot_attrib_tolerance[] = {
598 	&dev_attr_tolerance0.attr,
599 	&dev_attr_tolerance1.attr,
600 	&dev_attr_tolerance2.attr,
601 	&dev_attr_tolerance3.attr,
602 	&dev_attr_tolerance4.attr,
603 	&dev_attr_tolerance5.attr,
604 	NULL
605 };
606 
607 /* ------------------------------------------------------------------------- */
608 
609 #define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
610 set_##_name(struct device *dev, \
611 			 struct device_attribute *attr, \
612 			 const char *buf, size_t count) \
613 { \
614 	return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
615 } \
616 static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name)
617 
618 DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
619 DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
620 DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
621 DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);
622 
623 static struct attribute *ad525x_attributes_commands[] = {
624 	&dev_attr_inc_all.attr,
625 	&dev_attr_dec_all.attr,
626 	&dev_attr_inc_all_6db.attr,
627 	&dev_attr_dec_all_6db.attr,
628 	NULL
629 };
630 
631 static const struct attribute_group ad525x_group_commands = {
632 	.attrs = ad525x_attributes_commands,
633 };
634 
635 static int ad_dpot_add_files(struct device *dev,
636 		unsigned int features, unsigned int rdac)
637 {
638 	int err = sysfs_create_file(&dev->kobj,
639 		dpot_attrib_wipers[rdac]);
640 	if (features & F_CMD_EEP)
641 		err |= sysfs_create_file(&dev->kobj,
642 			dpot_attrib_eeprom[rdac]);
643 	if (features & F_CMD_TOL)
644 		err |= sysfs_create_file(&dev->kobj,
645 			dpot_attrib_tolerance[rdac]);
646 	if (features & F_CMD_OTP) {
647 		err |= sysfs_create_file(&dev->kobj,
648 			dpot_attrib_otp_en[rdac]);
649 		err |= sysfs_create_file(&dev->kobj,
650 			dpot_attrib_otp[rdac]);
651 	}
652 
653 	if (err)
654 		dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
655 			rdac);
656 
657 	return err;
658 }
659 
660 static inline void ad_dpot_remove_files(struct device *dev,
661 		unsigned int features, unsigned int rdac)
662 {
663 	sysfs_remove_file(&dev->kobj,
664 		dpot_attrib_wipers[rdac]);
665 	if (features & F_CMD_EEP)
666 		sysfs_remove_file(&dev->kobj,
667 			dpot_attrib_eeprom[rdac]);
668 	if (features & F_CMD_TOL)
669 		sysfs_remove_file(&dev->kobj,
670 			dpot_attrib_tolerance[rdac]);
671 	if (features & F_CMD_OTP) {
672 		sysfs_remove_file(&dev->kobj,
673 			dpot_attrib_otp_en[rdac]);
674 		sysfs_remove_file(&dev->kobj,
675 			dpot_attrib_otp[rdac]);
676 	}
677 }
678 
679 int ad_dpot_probe(struct device *dev,
680 		struct ad_dpot_bus_data *bdata, unsigned long devid,
681 			    const char *name)
682 {
683 
684 	struct dpot_data *data;
685 	int i, err = 0;
686 
687 	data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
688 	if (!data) {
689 		err = -ENOMEM;
690 		goto exit;
691 	}
692 
693 	dev_set_drvdata(dev, data);
694 	mutex_init(&data->update_lock);
695 
696 	data->bdata = *bdata;
697 	data->devid = devid;
698 
699 	data->max_pos = 1 << DPOT_MAX_POS(devid);
700 	data->rdac_mask = data->max_pos - 1;
701 	data->feat = DPOT_FEAT(devid);
702 	data->uid = DPOT_UID(devid);
703 	data->wipers = DPOT_WIPERS(devid);
704 
705 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
706 		if (data->wipers & (1 << i)) {
707 			err = ad_dpot_add_files(dev, data->feat, i);
708 			if (err)
709 				goto exit_remove_files;
710 			/* power-up midscale */
711 			if (data->feat & F_RDACS_WONLY)
712 				data->rdac_cache[i] = data->max_pos / 2;
713 		}
714 
715 	if (data->feat & F_CMD_INC)
716 		err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);
717 
718 	if (err) {
719 		dev_err(dev, "failed to register sysfs hooks\n");
720 		goto exit_free;
721 	}
722 
723 	dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
724 		 name, data->max_pos);
725 
726 	return 0;
727 
728 exit_remove_files:
729 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
730 		if (data->wipers & (1 << i))
731 			ad_dpot_remove_files(dev, data->feat, i);
732 
733 exit_free:
734 	kfree(data);
735 	dev_set_drvdata(dev, NULL);
736 exit:
737 	dev_err(dev, "failed to create client for %s ID 0x%lX\n",
738 		name, devid);
739 	return err;
740 }
741 EXPORT_SYMBOL(ad_dpot_probe);
742 
743 int ad_dpot_remove(struct device *dev)
744 {
745 	struct dpot_data *data = dev_get_drvdata(dev);
746 	int i;
747 
748 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
749 		if (data->wipers & (1 << i))
750 			ad_dpot_remove_files(dev, data->feat, i);
751 
752 	kfree(data);
753 
754 	return 0;
755 }
756 EXPORT_SYMBOL(ad_dpot_remove);
757 
758 
759 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
760 	      "Michael Hennerich <michael.hennerich@analog.com>");
761 MODULE_DESCRIPTION("Digital potentiometer driver");
762 MODULE_LICENSE("GPL");
763