xref: /openbmc/linux/drivers/misc/ad525x_dpot.c (revision ca55b2fe)
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) 2006-2011 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/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 rdac_mask;
88 	unsigned max_pos;
89 	unsigned long devid;
90 	unsigned uid;
91 	unsigned feat;
92 	unsigned 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 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 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,
209 				DPOT_AD5270_1_2_4_RDAC << 2);
210 
211 			if (value < 0)
212 				return value;
213 			/*
214 			 * AD5272/AD5274 returns high byte first, however
215 			 * underling smbus expects low byte first.
216 			 */
217 			value = swab16(value);
218 
219 			if (dpot->uid == DPOT_UID(AD5271_ID))
220 				value = value >> 2;
221 		return value;
222 	default:
223 		if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
224 			return dpot_read_r8d16(dpot, (reg & 0xF8) |
225 					((reg & 0x7) << 1));
226 		else
227 			return dpot_read_r8d8(dpot, reg);
228 	}
229 }
230 
231 static s32 dpot_read(struct dpot_data *dpot, u8 reg)
232 {
233 	if (dpot->feat & F_SPI)
234 		return dpot_read_spi(dpot, reg);
235 	else
236 		return dpot_read_i2c(dpot, reg);
237 }
238 
239 static s32 dpot_write_spi(struct dpot_data *dpot, u8 reg, u16 value)
240 {
241 	unsigned val = 0;
242 
243 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD | DPOT_ADDR_OTP))) {
244 		if (dpot->feat & F_RDACS_WONLY)
245 			dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value;
246 
247 		if (dpot->feat & F_AD_APPDATA) {
248 			if (dpot->feat & F_SPI_8BIT) {
249 				val = ((reg & DPOT_RDAC_MASK) <<
250 					DPOT_MAX_POS(dpot->devid)) |
251 					value;
252 				return dpot_write_d8(dpot, val);
253 			} else if (dpot->feat & F_SPI_16BIT) {
254 				val = ((reg & DPOT_RDAC_MASK) <<
255 					DPOT_MAX_POS(dpot->devid)) |
256 					value;
257 				return dpot_write_r8d8(dpot, val >> 8,
258 					val & 0xFF);
259 			} else
260 				BUG();
261 		} else {
262 			if (dpot->uid == DPOT_UID(AD5291_ID) ||
263 				dpot->uid == DPOT_UID(AD5292_ID) ||
264 				dpot->uid == DPOT_UID(AD5293_ID)) {
265 
266 				dpot_write_r8d8(dpot, DPOT_AD5291_CTRLREG << 2,
267 						DPOT_AD5291_UNLOCK_CMD);
268 
269 				if (dpot->uid == DPOT_UID(AD5291_ID))
270 					value = value << 2;
271 
272 				return dpot_write_r8d8(dpot,
273 					(DPOT_AD5291_RDAC << 2) |
274 					(value >> 8), value & 0xFF);
275 			} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
276 				dpot->uid == DPOT_UID(AD5271_ID)) {
277 				dpot_write_r8d8(dpot,
278 						DPOT_AD5270_1_2_4_CTRLREG << 2,
279 						DPOT_AD5270_1_2_4_UNLOCK_CMD);
280 
281 				if (dpot->uid == DPOT_UID(AD5271_ID))
282 					value = value << 2;
283 
284 				return dpot_write_r8d8(dpot,
285 					(DPOT_AD5270_1_2_4_RDAC << 2) |
286 					(value >> 8), value & 0xFF);
287 			}
288 			val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK);
289 		}
290 	} else if (reg & DPOT_ADDR_EEPROM) {
291 		val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK);
292 	} else if (reg & DPOT_ADDR_CMD) {
293 		switch (reg) {
294 		case DPOT_DEC_ALL_6DB:
295 			val = DPOT_SPI_DEC_ALL_6DB;
296 			break;
297 		case DPOT_INC_ALL_6DB:
298 			val = DPOT_SPI_INC_ALL_6DB;
299 			break;
300 		case DPOT_DEC_ALL:
301 			val = DPOT_SPI_DEC_ALL;
302 			break;
303 		case DPOT_INC_ALL:
304 			val = DPOT_SPI_INC_ALL;
305 			break;
306 		}
307 	} else if (reg & DPOT_ADDR_OTP) {
308 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
309 			dpot->uid == DPOT_UID(AD5292_ID)) {
310 			return dpot_write_r8d8(dpot,
311 				DPOT_AD5291_STORE_XTPM << 2, 0);
312 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
313 			dpot->uid == DPOT_UID(AD5271_ID)) {
314 			return dpot_write_r8d8(dpot,
315 				DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
316 		}
317 	} else
318 		BUG();
319 
320 	if (dpot->feat & F_SPI_16BIT)
321 		return dpot_write_r8d8(dpot, val, value);
322 	else if (dpot->feat & F_SPI_24BIT)
323 		return dpot_write_r8d16(dpot, val, value);
324 
325 	return -EFAULT;
326 }
327 
328 static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
329 {
330 	/* Only write the instruction byte for certain commands */
331 	unsigned tmp = 0, ctrl = 0;
332 
333 	switch (dpot->uid) {
334 	case DPOT_UID(AD5246_ID):
335 	case DPOT_UID(AD5247_ID):
336 		return dpot_write_d8(dpot, value);
337 
338 	case DPOT_UID(AD5245_ID):
339 	case DPOT_UID(AD5241_ID):
340 	case DPOT_UID(AD5242_ID):
341 	case DPOT_UID(AD5243_ID):
342 	case DPOT_UID(AD5248_ID):
343 	case DPOT_UID(AD5280_ID):
344 	case DPOT_UID(AD5282_ID):
345 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
346 			0 : DPOT_AD5282_RDAC_AB;
347 		return dpot_write_r8d8(dpot, ctrl, value);
348 	case DPOT_UID(AD5171_ID):
349 	case DPOT_UID(AD5273_ID):
350 		if (reg & DPOT_ADDR_OTP) {
351 			tmp = dpot_read_d8(dpot);
352 			if (tmp >> 6) /* Ready to Program? */
353 				return -EFAULT;
354 			ctrl = DPOT_AD5273_FUSE;
355 		}
356 		return dpot_write_r8d8(dpot, ctrl, value);
357 	case DPOT_UID(AD5172_ID):
358 	case DPOT_UID(AD5173_ID):
359 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
360 			0 : DPOT_AD5172_3_A0;
361 		if (reg & DPOT_ADDR_OTP) {
362 			tmp = dpot_read_r8d16(dpot, ctrl);
363 			if (tmp >> 14) /* Ready to Program? */
364 				return -EFAULT;
365 			ctrl |= DPOT_AD5170_2_3_FUSE;
366 		}
367 		return dpot_write_r8d8(dpot, ctrl, value);
368 	case DPOT_UID(AD5170_ID):
369 		if (reg & DPOT_ADDR_OTP) {
370 			tmp = dpot_read_r8d16(dpot, tmp);
371 			if (tmp >> 14) /* Ready to Program? */
372 				return -EFAULT;
373 			ctrl = DPOT_AD5170_2_3_FUSE;
374 		}
375 		return dpot_write_r8d8(dpot, ctrl, value);
376 	case DPOT_UID(AD5272_ID):
377 	case DPOT_UID(AD5274_ID):
378 		dpot_write_r8d8(dpot, DPOT_AD5270_1_2_4_CTRLREG << 2,
379 				DPOT_AD5270_1_2_4_UNLOCK_CMD);
380 
381 		if (reg & DPOT_ADDR_OTP)
382 			return dpot_write_r8d8(dpot,
383 					DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
384 
385 		if (dpot->uid == DPOT_UID(AD5274_ID))
386 			value = value << 2;
387 
388 		return dpot_write_r8d8(dpot, (DPOT_AD5270_1_2_4_RDAC << 2) |
389 				       (value >> 8), value & 0xFF);
390 	default:
391 		if (reg & DPOT_ADDR_CMD)
392 			return dpot_write_d8(dpot, reg);
393 
394 		if (dpot->max_pos > 256)
395 			return dpot_write_r8d16(dpot, (reg & 0xF8) |
396 						((reg & 0x7) << 1), value);
397 		else
398 			/* All other registers require instruction + data bytes */
399 			return dpot_write_r8d8(dpot, reg, value);
400 	}
401 }
402 
403 static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
404 {
405 	if (dpot->feat & F_SPI)
406 		return dpot_write_spi(dpot, reg, value);
407 	else
408 		return dpot_write_i2c(dpot, reg, value);
409 }
410 
411 /* sysfs functions */
412 
413 static ssize_t sysfs_show_reg(struct device *dev,
414 			      struct device_attribute *attr,
415 			      char *buf, u32 reg)
416 {
417 	struct dpot_data *data = dev_get_drvdata(dev);
418 	s32 value;
419 
420 	if (reg & DPOT_ADDR_OTP_EN)
421 		return sprintf(buf, "%s\n",
422 			test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask) ?
423 			"enabled" : "disabled");
424 
425 
426 	mutex_lock(&data->update_lock);
427 	value = dpot_read(data, reg);
428 	mutex_unlock(&data->update_lock);
429 
430 	if (value < 0)
431 		return -EINVAL;
432 	/*
433 	 * Let someone else deal with converting this ...
434 	 * the tolerance is a two-byte value where the MSB
435 	 * is a sign + integer value, and the LSB is a
436 	 * decimal value.  See page 18 of the AD5258
437 	 * datasheet (Rev. A) for more details.
438 	 */
439 
440 	if (reg & DPOT_REG_TOL)
441 		return sprintf(buf, "0x%04x\n", value & 0xFFFF);
442 	else
443 		return sprintf(buf, "%u\n", value & data->rdac_mask);
444 }
445 
446 static ssize_t sysfs_set_reg(struct device *dev,
447 			     struct device_attribute *attr,
448 			     const char *buf, size_t count, u32 reg)
449 {
450 	struct dpot_data *data = dev_get_drvdata(dev);
451 	unsigned long value;
452 	int err;
453 
454 	if (reg & DPOT_ADDR_OTP_EN) {
455 		if (!strncmp(buf, "enabled", sizeof("enabled")))
456 			set_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
457 		else
458 			clear_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
459 
460 		return count;
461 	}
462 
463 	if ((reg & DPOT_ADDR_OTP) &&
464 		!test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask))
465 		return -EPERM;
466 
467 	err = kstrtoul(buf, 10, &value);
468 	if (err)
469 		return err;
470 
471 	if (value > data->rdac_mask)
472 		value = data->rdac_mask;
473 
474 	mutex_lock(&data->update_lock);
475 	dpot_write(data, reg, value);
476 	if (reg & DPOT_ADDR_EEPROM)
477 		msleep(26);	/* Sleep while the EEPROM updates */
478 	else if (reg & DPOT_ADDR_OTP)
479 		msleep(400);	/* Sleep while the OTP updates */
480 	mutex_unlock(&data->update_lock);
481 
482 	return count;
483 }
484 
485 static ssize_t sysfs_do_cmd(struct device *dev,
486 			    struct device_attribute *attr,
487 			    const char *buf, size_t count, u32 reg)
488 {
489 	struct dpot_data *data = dev_get_drvdata(dev);
490 
491 	mutex_lock(&data->update_lock);
492 	dpot_write(data, reg, 0);
493 	mutex_unlock(&data->update_lock);
494 
495 	return count;
496 }
497 
498 /* ------------------------------------------------------------------------- */
499 
500 #define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
501 show_##_name(struct device *dev, \
502 			  struct device_attribute *attr, char *buf) \
503 { \
504 	return sysfs_show_reg(dev, attr, buf, _reg); \
505 }
506 
507 #define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
508 set_##_name(struct device *dev, \
509 			 struct device_attribute *attr, \
510 			 const char *buf, size_t count) \
511 { \
512 	return sysfs_set_reg(dev, attr, buf, count, _reg); \
513 }
514 
515 #define DPOT_DEVICE_SHOW_SET(name, reg) \
516 DPOT_DEVICE_SHOW(name, reg) \
517 DPOT_DEVICE_SET(name, reg) \
518 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name);
519 
520 #define DPOT_DEVICE_SHOW_ONLY(name, reg) \
521 DPOT_DEVICE_SHOW(name, reg) \
522 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL);
523 
524 DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
525 DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
526 DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
527 DPOT_DEVICE_SHOW_SET(otp0, DPOT_ADDR_OTP | DPOT_RDAC0);
528 DPOT_DEVICE_SHOW_SET(otp0en, DPOT_ADDR_OTP_EN | DPOT_RDAC0);
529 
530 DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
531 DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
532 DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
533 DPOT_DEVICE_SHOW_SET(otp1, DPOT_ADDR_OTP | DPOT_RDAC1);
534 DPOT_DEVICE_SHOW_SET(otp1en, DPOT_ADDR_OTP_EN | DPOT_RDAC1);
535 
536 DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
537 DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
538 DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
539 DPOT_DEVICE_SHOW_SET(otp2, DPOT_ADDR_OTP | DPOT_RDAC2);
540 DPOT_DEVICE_SHOW_SET(otp2en, DPOT_ADDR_OTP_EN | DPOT_RDAC2);
541 
542 DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
543 DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
544 DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
545 DPOT_DEVICE_SHOW_SET(otp3, DPOT_ADDR_OTP | DPOT_RDAC3);
546 DPOT_DEVICE_SHOW_SET(otp3en, DPOT_ADDR_OTP_EN | DPOT_RDAC3);
547 
548 DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
549 DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
550 DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
551 DPOT_DEVICE_SHOW_SET(otp4, DPOT_ADDR_OTP | DPOT_RDAC4);
552 DPOT_DEVICE_SHOW_SET(otp4en, DPOT_ADDR_OTP_EN | DPOT_RDAC4);
553 
554 DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
555 DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
556 DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
557 DPOT_DEVICE_SHOW_SET(otp5, DPOT_ADDR_OTP | DPOT_RDAC5);
558 DPOT_DEVICE_SHOW_SET(otp5en, DPOT_ADDR_OTP_EN | DPOT_RDAC5);
559 
560 static const struct attribute *dpot_attrib_wipers[] = {
561 	&dev_attr_rdac0.attr,
562 	&dev_attr_rdac1.attr,
563 	&dev_attr_rdac2.attr,
564 	&dev_attr_rdac3.attr,
565 	&dev_attr_rdac4.attr,
566 	&dev_attr_rdac5.attr,
567 	NULL
568 };
569 
570 static const struct attribute *dpot_attrib_eeprom[] = {
571 	&dev_attr_eeprom0.attr,
572 	&dev_attr_eeprom1.attr,
573 	&dev_attr_eeprom2.attr,
574 	&dev_attr_eeprom3.attr,
575 	&dev_attr_eeprom4.attr,
576 	&dev_attr_eeprom5.attr,
577 	NULL
578 };
579 
580 static const struct attribute *dpot_attrib_otp[] = {
581 	&dev_attr_otp0.attr,
582 	&dev_attr_otp1.attr,
583 	&dev_attr_otp2.attr,
584 	&dev_attr_otp3.attr,
585 	&dev_attr_otp4.attr,
586 	&dev_attr_otp5.attr,
587 	NULL
588 };
589 
590 static const struct attribute *dpot_attrib_otp_en[] = {
591 	&dev_attr_otp0en.attr,
592 	&dev_attr_otp1en.attr,
593 	&dev_attr_otp2en.attr,
594 	&dev_attr_otp3en.attr,
595 	&dev_attr_otp4en.attr,
596 	&dev_attr_otp5en.attr,
597 	NULL
598 };
599 
600 static const struct attribute *dpot_attrib_tolerance[] = {
601 	&dev_attr_tolerance0.attr,
602 	&dev_attr_tolerance1.attr,
603 	&dev_attr_tolerance2.attr,
604 	&dev_attr_tolerance3.attr,
605 	&dev_attr_tolerance4.attr,
606 	&dev_attr_tolerance5.attr,
607 	NULL
608 };
609 
610 /* ------------------------------------------------------------------------- */
611 
612 #define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
613 set_##_name(struct device *dev, \
614 			 struct device_attribute *attr, \
615 			 const char *buf, size_t count) \
616 { \
617 	return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
618 } \
619 static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name);
620 
621 DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
622 DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
623 DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
624 DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);
625 
626 static struct attribute *ad525x_attributes_commands[] = {
627 	&dev_attr_inc_all.attr,
628 	&dev_attr_dec_all.attr,
629 	&dev_attr_inc_all_6db.attr,
630 	&dev_attr_dec_all_6db.attr,
631 	NULL
632 };
633 
634 static const struct attribute_group ad525x_group_commands = {
635 	.attrs = ad525x_attributes_commands,
636 };
637 
638 static int ad_dpot_add_files(struct device *dev,
639 		unsigned features, unsigned rdac)
640 {
641 	int err = sysfs_create_file(&dev->kobj,
642 		dpot_attrib_wipers[rdac]);
643 	if (features & F_CMD_EEP)
644 		err |= sysfs_create_file(&dev->kobj,
645 			dpot_attrib_eeprom[rdac]);
646 	if (features & F_CMD_TOL)
647 		err |= sysfs_create_file(&dev->kobj,
648 			dpot_attrib_tolerance[rdac]);
649 	if (features & F_CMD_OTP) {
650 		err |= sysfs_create_file(&dev->kobj,
651 			dpot_attrib_otp_en[rdac]);
652 		err |= sysfs_create_file(&dev->kobj,
653 			dpot_attrib_otp[rdac]);
654 	}
655 
656 	if (err)
657 		dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
658 			rdac);
659 
660 	return err;
661 }
662 
663 static inline void ad_dpot_remove_files(struct device *dev,
664 		unsigned features, unsigned rdac)
665 {
666 	sysfs_remove_file(&dev->kobj,
667 		dpot_attrib_wipers[rdac]);
668 	if (features & F_CMD_EEP)
669 		sysfs_remove_file(&dev->kobj,
670 			dpot_attrib_eeprom[rdac]);
671 	if (features & F_CMD_TOL)
672 		sysfs_remove_file(&dev->kobj,
673 			dpot_attrib_tolerance[rdac]);
674 	if (features & F_CMD_OTP) {
675 		sysfs_remove_file(&dev->kobj,
676 			dpot_attrib_otp_en[rdac]);
677 		sysfs_remove_file(&dev->kobj,
678 			dpot_attrib_otp[rdac]);
679 	}
680 }
681 
682 int ad_dpot_probe(struct device *dev,
683 		struct ad_dpot_bus_data *bdata, unsigned long devid,
684 			    const char *name)
685 {
686 
687 	struct dpot_data *data;
688 	int i, err = 0;
689 
690 	data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
691 	if (!data) {
692 		err = -ENOMEM;
693 		goto exit;
694 	}
695 
696 	dev_set_drvdata(dev, data);
697 	mutex_init(&data->update_lock);
698 
699 	data->bdata = *bdata;
700 	data->devid = devid;
701 
702 	data->max_pos = 1 << DPOT_MAX_POS(devid);
703 	data->rdac_mask = data->max_pos - 1;
704 	data->feat = DPOT_FEAT(devid);
705 	data->uid = DPOT_UID(devid);
706 	data->wipers = DPOT_WIPERS(devid);
707 
708 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
709 		if (data->wipers & (1 << i)) {
710 			err = ad_dpot_add_files(dev, data->feat, i);
711 			if (err)
712 				goto exit_remove_files;
713 			/* power-up midscale */
714 			if (data->feat & F_RDACS_WONLY)
715 				data->rdac_cache[i] = data->max_pos / 2;
716 		}
717 
718 	if (data->feat & F_CMD_INC)
719 		err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);
720 
721 	if (err) {
722 		dev_err(dev, "failed to register sysfs hooks\n");
723 		goto exit_free;
724 	}
725 
726 	dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
727 		 name, data->max_pos);
728 
729 	return 0;
730 
731 exit_remove_files:
732 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
733 		if (data->wipers & (1 << i))
734 			ad_dpot_remove_files(dev, data->feat, i);
735 
736 exit_free:
737 	kfree(data);
738 	dev_set_drvdata(dev, NULL);
739 exit:
740 	dev_err(dev, "failed to create client for %s ID 0x%lX\n",
741 		name, devid);
742 	return err;
743 }
744 EXPORT_SYMBOL(ad_dpot_probe);
745 
746 int ad_dpot_remove(struct device *dev)
747 {
748 	struct dpot_data *data = dev_get_drvdata(dev);
749 	int i;
750 
751 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
752 		if (data->wipers & (1 << i))
753 			ad_dpot_remove_files(dev, data->feat, i);
754 
755 	kfree(data);
756 
757 	return 0;
758 }
759 EXPORT_SYMBOL(ad_dpot_remove);
760 
761 
762 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
763 	      "Michael Hennerich <hennerich@blackfin.uclinux.org>");
764 MODULE_DESCRIPTION("Digital potentiometer driver");
765 MODULE_LICENSE("GPL");
766