xref: /openbmc/linux/drivers/misc/ad525x_dpot.c (revision 63dc02bd)
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/init.h>
76 #include <linux/delay.h>
77 #include <linux/slab.h>
78 
79 #include "ad525x_dpot.h"
80 
81 /*
82  * Client data (each client gets its own)
83  */
84 
85 struct dpot_data {
86 	struct ad_dpot_bus_data	bdata;
87 	struct mutex update_lock;
88 	unsigned rdac_mask;
89 	unsigned max_pos;
90 	unsigned long devid;
91 	unsigned uid;
92 	unsigned feat;
93 	unsigned wipers;
94 	u16 rdac_cache[MAX_RDACS];
95 	DECLARE_BITMAP(otp_en_mask, MAX_RDACS);
96 };
97 
98 static inline int dpot_read_d8(struct dpot_data *dpot)
99 {
100 	return dpot->bdata.bops->read_d8(dpot->bdata.client);
101 }
102 
103 static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg)
104 {
105 	return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg);
106 }
107 
108 static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg)
109 {
110 	return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg);
111 }
112 
113 static inline int dpot_write_d8(struct dpot_data *dpot, u8 val)
114 {
115 	return dpot->bdata.bops->write_d8(dpot->bdata.client, val);
116 }
117 
118 static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val)
119 {
120 	return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val);
121 }
122 
123 static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val)
124 {
125 	return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val);
126 }
127 
128 static s32 dpot_read_spi(struct dpot_data *dpot, u8 reg)
129 {
130 	unsigned ctrl = 0;
131 	int value;
132 
133 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
134 
135 		if (dpot->feat & F_RDACS_WONLY)
136 			return dpot->rdac_cache[reg & DPOT_RDAC_MASK];
137 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
138 			dpot->uid == DPOT_UID(AD5292_ID) ||
139 			dpot->uid == DPOT_UID(AD5293_ID)) {
140 
141 			value = dpot_read_r8d8(dpot,
142 				DPOT_AD5291_READ_RDAC << 2);
143 
144 			if (dpot->uid == DPOT_UID(AD5291_ID))
145 				value = value >> 2;
146 
147 			return value;
148 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
149 			dpot->uid == DPOT_UID(AD5271_ID)) {
150 
151 			value = dpot_read_r8d8(dpot,
152 				DPOT_AD5270_1_2_4_READ_RDAC << 2);
153 
154 			if (value < 0)
155 				return value;
156 
157 			if (dpot->uid == DPOT_UID(AD5271_ID))
158 				value = value >> 2;
159 
160 			return value;
161 		}
162 
163 		ctrl = DPOT_SPI_READ_RDAC;
164 	} else if (reg & DPOT_ADDR_EEPROM) {
165 		ctrl = DPOT_SPI_READ_EEPROM;
166 	}
167 
168 	if (dpot->feat & F_SPI_16BIT)
169 		return dpot_read_r8d8(dpot, ctrl);
170 	else if (dpot->feat & F_SPI_24BIT)
171 		return dpot_read_r8d16(dpot, ctrl);
172 
173 	return -EFAULT;
174 }
175 
176 static s32 dpot_read_i2c(struct dpot_data *dpot, u8 reg)
177 {
178 	int value;
179 	unsigned ctrl = 0;
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 		break;
338 
339 	case DPOT_UID(AD5245_ID):
340 	case DPOT_UID(AD5241_ID):
341 	case DPOT_UID(AD5242_ID):
342 	case DPOT_UID(AD5243_ID):
343 	case DPOT_UID(AD5248_ID):
344 	case DPOT_UID(AD5280_ID):
345 	case DPOT_UID(AD5282_ID):
346 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
347 			0 : DPOT_AD5282_RDAC_AB;
348 		return dpot_write_r8d8(dpot, ctrl, value);
349 		break;
350 	case DPOT_UID(AD5171_ID):
351 	case DPOT_UID(AD5273_ID):
352 		if (reg & DPOT_ADDR_OTP) {
353 			tmp = dpot_read_d8(dpot);
354 			if (tmp >> 6) /* Ready to Program? */
355 				return -EFAULT;
356 			ctrl = DPOT_AD5273_FUSE;
357 		}
358 		return dpot_write_r8d8(dpot, ctrl, value);
359 		break;
360 	case DPOT_UID(AD5172_ID):
361 	case DPOT_UID(AD5173_ID):
362 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
363 			0 : DPOT_AD5172_3_A0;
364 		if (reg & DPOT_ADDR_OTP) {
365 			tmp = dpot_read_r8d16(dpot, ctrl);
366 			if (tmp >> 14) /* Ready to Program? */
367 				return -EFAULT;
368 			ctrl |= DPOT_AD5170_2_3_FUSE;
369 		}
370 		return dpot_write_r8d8(dpot, ctrl, value);
371 		break;
372 	case DPOT_UID(AD5170_ID):
373 		if (reg & DPOT_ADDR_OTP) {
374 			tmp = dpot_read_r8d16(dpot, tmp);
375 			if (tmp >> 14) /* Ready to Program? */
376 				return -EFAULT;
377 			ctrl = DPOT_AD5170_2_3_FUSE;
378 		}
379 		return dpot_write_r8d8(dpot, ctrl, value);
380 		break;
381 	case DPOT_UID(AD5272_ID):
382 	case DPOT_UID(AD5274_ID):
383 		dpot_write_r8d8(dpot, DPOT_AD5270_1_2_4_CTRLREG << 2,
384 				DPOT_AD5270_1_2_4_UNLOCK_CMD);
385 
386 		if (reg & DPOT_ADDR_OTP)
387 			return dpot_write_r8d8(dpot,
388 					DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
389 
390 		if (dpot->uid == DPOT_UID(AD5274_ID))
391 			value = value << 2;
392 
393 		return dpot_write_r8d8(dpot, (DPOT_AD5270_1_2_4_RDAC << 2) |
394 				       (value >> 8), value & 0xFF);
395 		break;
396 	default:
397 		if (reg & DPOT_ADDR_CMD)
398 			return dpot_write_d8(dpot, reg);
399 
400 		if (dpot->max_pos > 256)
401 			return dpot_write_r8d16(dpot, (reg & 0xF8) |
402 						((reg & 0x7) << 1), value);
403 		else
404 			/* All other registers require instruction + data bytes */
405 			return dpot_write_r8d8(dpot, reg, value);
406 	}
407 }
408 
409 static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
410 {
411 	if (dpot->feat & F_SPI)
412 		return dpot_write_spi(dpot, reg, value);
413 	else
414 		return dpot_write_i2c(dpot, reg, value);
415 }
416 
417 /* sysfs functions */
418 
419 static ssize_t sysfs_show_reg(struct device *dev,
420 			      struct device_attribute *attr,
421 			      char *buf, u32 reg)
422 {
423 	struct dpot_data *data = dev_get_drvdata(dev);
424 	s32 value;
425 
426 	if (reg & DPOT_ADDR_OTP_EN)
427 		return sprintf(buf, "%s\n",
428 			test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask) ?
429 			"enabled" : "disabled");
430 
431 
432 	mutex_lock(&data->update_lock);
433 	value = dpot_read(data, reg);
434 	mutex_unlock(&data->update_lock);
435 
436 	if (value < 0)
437 		return -EINVAL;
438 	/*
439 	 * Let someone else deal with converting this ...
440 	 * the tolerance is a two-byte value where the MSB
441 	 * is a sign + integer value, and the LSB is a
442 	 * decimal value.  See page 18 of the AD5258
443 	 * datasheet (Rev. A) for more details.
444 	 */
445 
446 	if (reg & DPOT_REG_TOL)
447 		return sprintf(buf, "0x%04x\n", value & 0xFFFF);
448 	else
449 		return sprintf(buf, "%u\n", value & data->rdac_mask);
450 }
451 
452 static ssize_t sysfs_set_reg(struct device *dev,
453 			     struct device_attribute *attr,
454 			     const char *buf, size_t count, u32 reg)
455 {
456 	struct dpot_data *data = dev_get_drvdata(dev);
457 	unsigned long value;
458 	int err;
459 
460 	if (reg & DPOT_ADDR_OTP_EN) {
461 		if (!strncmp(buf, "enabled", sizeof("enabled")))
462 			set_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
463 		else
464 			clear_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
465 
466 		return count;
467 	}
468 
469 	if ((reg & DPOT_ADDR_OTP) &&
470 		!test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask))
471 		return -EPERM;
472 
473 	err = strict_strtoul(buf, 10, &value);
474 	if (err)
475 		return err;
476 
477 	if (value > data->rdac_mask)
478 		value = data->rdac_mask;
479 
480 	mutex_lock(&data->update_lock);
481 	dpot_write(data, reg, value);
482 	if (reg & DPOT_ADDR_EEPROM)
483 		msleep(26);	/* Sleep while the EEPROM updates */
484 	else if (reg & DPOT_ADDR_OTP)
485 		msleep(400);	/* Sleep while the OTP updates */
486 	mutex_unlock(&data->update_lock);
487 
488 	return count;
489 }
490 
491 static ssize_t sysfs_do_cmd(struct device *dev,
492 			    struct device_attribute *attr,
493 			    const char *buf, size_t count, u32 reg)
494 {
495 	struct dpot_data *data = dev_get_drvdata(dev);
496 
497 	mutex_lock(&data->update_lock);
498 	dpot_write(data, reg, 0);
499 	mutex_unlock(&data->update_lock);
500 
501 	return count;
502 }
503 
504 /* ------------------------------------------------------------------------- */
505 
506 #define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
507 show_##_name(struct device *dev, \
508 			  struct device_attribute *attr, char *buf) \
509 { \
510 	return sysfs_show_reg(dev, attr, buf, _reg); \
511 }
512 
513 #define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
514 set_##_name(struct device *dev, \
515 			 struct device_attribute *attr, \
516 			 const char *buf, size_t count) \
517 { \
518 	return sysfs_set_reg(dev, attr, buf, count, _reg); \
519 }
520 
521 #define DPOT_DEVICE_SHOW_SET(name, reg) \
522 DPOT_DEVICE_SHOW(name, reg) \
523 DPOT_DEVICE_SET(name, reg) \
524 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name);
525 
526 #define DPOT_DEVICE_SHOW_ONLY(name, reg) \
527 DPOT_DEVICE_SHOW(name, reg) \
528 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL);
529 
530 DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
531 DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
532 DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
533 DPOT_DEVICE_SHOW_SET(otp0, DPOT_ADDR_OTP | DPOT_RDAC0);
534 DPOT_DEVICE_SHOW_SET(otp0en, DPOT_ADDR_OTP_EN | DPOT_RDAC0);
535 
536 DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
537 DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
538 DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
539 DPOT_DEVICE_SHOW_SET(otp1, DPOT_ADDR_OTP | DPOT_RDAC1);
540 DPOT_DEVICE_SHOW_SET(otp1en, DPOT_ADDR_OTP_EN | DPOT_RDAC1);
541 
542 DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
543 DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
544 DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
545 DPOT_DEVICE_SHOW_SET(otp2, DPOT_ADDR_OTP | DPOT_RDAC2);
546 DPOT_DEVICE_SHOW_SET(otp2en, DPOT_ADDR_OTP_EN | DPOT_RDAC2);
547 
548 DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
549 DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
550 DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
551 DPOT_DEVICE_SHOW_SET(otp3, DPOT_ADDR_OTP | DPOT_RDAC3);
552 DPOT_DEVICE_SHOW_SET(otp3en, DPOT_ADDR_OTP_EN | DPOT_RDAC3);
553 
554 DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
555 DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
556 DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
557 DPOT_DEVICE_SHOW_SET(otp4, DPOT_ADDR_OTP | DPOT_RDAC4);
558 DPOT_DEVICE_SHOW_SET(otp4en, DPOT_ADDR_OTP_EN | DPOT_RDAC4);
559 
560 DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
561 DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
562 DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
563 DPOT_DEVICE_SHOW_SET(otp5, DPOT_ADDR_OTP | DPOT_RDAC5);
564 DPOT_DEVICE_SHOW_SET(otp5en, DPOT_ADDR_OTP_EN | DPOT_RDAC5);
565 
566 static const struct attribute *dpot_attrib_wipers[] = {
567 	&dev_attr_rdac0.attr,
568 	&dev_attr_rdac1.attr,
569 	&dev_attr_rdac2.attr,
570 	&dev_attr_rdac3.attr,
571 	&dev_attr_rdac4.attr,
572 	&dev_attr_rdac5.attr,
573 	NULL
574 };
575 
576 static const struct attribute *dpot_attrib_eeprom[] = {
577 	&dev_attr_eeprom0.attr,
578 	&dev_attr_eeprom1.attr,
579 	&dev_attr_eeprom2.attr,
580 	&dev_attr_eeprom3.attr,
581 	&dev_attr_eeprom4.attr,
582 	&dev_attr_eeprom5.attr,
583 	NULL
584 };
585 
586 static const struct attribute *dpot_attrib_otp[] = {
587 	&dev_attr_otp0.attr,
588 	&dev_attr_otp1.attr,
589 	&dev_attr_otp2.attr,
590 	&dev_attr_otp3.attr,
591 	&dev_attr_otp4.attr,
592 	&dev_attr_otp5.attr,
593 	NULL
594 };
595 
596 static const struct attribute *dpot_attrib_otp_en[] = {
597 	&dev_attr_otp0en.attr,
598 	&dev_attr_otp1en.attr,
599 	&dev_attr_otp2en.attr,
600 	&dev_attr_otp3en.attr,
601 	&dev_attr_otp4en.attr,
602 	&dev_attr_otp5en.attr,
603 	NULL
604 };
605 
606 static const struct attribute *dpot_attrib_tolerance[] = {
607 	&dev_attr_tolerance0.attr,
608 	&dev_attr_tolerance1.attr,
609 	&dev_attr_tolerance2.attr,
610 	&dev_attr_tolerance3.attr,
611 	&dev_attr_tolerance4.attr,
612 	&dev_attr_tolerance5.attr,
613 	NULL
614 };
615 
616 /* ------------------------------------------------------------------------- */
617 
618 #define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
619 set_##_name(struct device *dev, \
620 			 struct device_attribute *attr, \
621 			 const char *buf, size_t count) \
622 { \
623 	return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
624 } \
625 static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name);
626 
627 DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
628 DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
629 DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
630 DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);
631 
632 static struct attribute *ad525x_attributes_commands[] = {
633 	&dev_attr_inc_all.attr,
634 	&dev_attr_dec_all.attr,
635 	&dev_attr_inc_all_6db.attr,
636 	&dev_attr_dec_all_6db.attr,
637 	NULL
638 };
639 
640 static const struct attribute_group ad525x_group_commands = {
641 	.attrs = ad525x_attributes_commands,
642 };
643 
644 __devinit int ad_dpot_add_files(struct device *dev,
645 		unsigned features, unsigned rdac)
646 {
647 	int err = sysfs_create_file(&dev->kobj,
648 		dpot_attrib_wipers[rdac]);
649 	if (features & F_CMD_EEP)
650 		err |= sysfs_create_file(&dev->kobj,
651 			dpot_attrib_eeprom[rdac]);
652 	if (features & F_CMD_TOL)
653 		err |= sysfs_create_file(&dev->kobj,
654 			dpot_attrib_tolerance[rdac]);
655 	if (features & F_CMD_OTP) {
656 		err |= sysfs_create_file(&dev->kobj,
657 			dpot_attrib_otp_en[rdac]);
658 		err |= sysfs_create_file(&dev->kobj,
659 			dpot_attrib_otp[rdac]);
660 	}
661 
662 	if (err)
663 		dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
664 			rdac);
665 
666 	return err;
667 }
668 
669 inline void ad_dpot_remove_files(struct device *dev,
670 		unsigned features, unsigned rdac)
671 {
672 	sysfs_remove_file(&dev->kobj,
673 		dpot_attrib_wipers[rdac]);
674 	if (features & F_CMD_EEP)
675 		sysfs_remove_file(&dev->kobj,
676 			dpot_attrib_eeprom[rdac]);
677 	if (features & F_CMD_TOL)
678 		sysfs_remove_file(&dev->kobj,
679 			dpot_attrib_tolerance[rdac]);
680 	if (features & F_CMD_OTP) {
681 		sysfs_remove_file(&dev->kobj,
682 			dpot_attrib_otp_en[rdac]);
683 		sysfs_remove_file(&dev->kobj,
684 			dpot_attrib_otp[rdac]);
685 	}
686 }
687 
688 int __devinit ad_dpot_probe(struct device *dev,
689 		struct ad_dpot_bus_data *bdata, unsigned long devid,
690 			    const char *name)
691 {
692 
693 	struct dpot_data *data;
694 	int i, err = 0;
695 
696 	data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
697 	if (!data) {
698 		err = -ENOMEM;
699 		goto exit;
700 	}
701 
702 	dev_set_drvdata(dev, data);
703 	mutex_init(&data->update_lock);
704 
705 	data->bdata = *bdata;
706 	data->devid = devid;
707 
708 	data->max_pos = 1 << DPOT_MAX_POS(devid);
709 	data->rdac_mask = data->max_pos - 1;
710 	data->feat = DPOT_FEAT(devid);
711 	data->uid = DPOT_UID(devid);
712 	data->wipers = DPOT_WIPERS(devid);
713 
714 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
715 		if (data->wipers & (1 << i)) {
716 			err = ad_dpot_add_files(dev, data->feat, i);
717 			if (err)
718 				goto exit_remove_files;
719 			/* power-up midscale */
720 			if (data->feat & F_RDACS_WONLY)
721 				data->rdac_cache[i] = data->max_pos / 2;
722 		}
723 
724 	if (data->feat & F_CMD_INC)
725 		err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);
726 
727 	if (err) {
728 		dev_err(dev, "failed to register sysfs hooks\n");
729 		goto exit_free;
730 	}
731 
732 	dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
733 		 name, data->max_pos);
734 
735 	return 0;
736 
737 exit_remove_files:
738 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
739 		if (data->wipers & (1 << i))
740 			ad_dpot_remove_files(dev, data->feat, i);
741 
742 exit_free:
743 	kfree(data);
744 	dev_set_drvdata(dev, NULL);
745 exit:
746 	dev_err(dev, "failed to create client for %s ID 0x%lX\n",
747 		name, devid);
748 	return err;
749 }
750 EXPORT_SYMBOL(ad_dpot_probe);
751 
752 __devexit int ad_dpot_remove(struct device *dev)
753 {
754 	struct dpot_data *data = dev_get_drvdata(dev);
755 	int i;
756 
757 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
758 		if (data->wipers & (1 << i))
759 			ad_dpot_remove_files(dev, data->feat, i);
760 
761 	kfree(data);
762 
763 	return 0;
764 }
765 EXPORT_SYMBOL(ad_dpot_remove);
766 
767 
768 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
769 	      "Michael Hennerich <hennerich@blackfin.uclinux.org>");
770 MODULE_DESCRIPTION("Digital potentiometer driver");
771 MODULE_LICENSE("GPL");
772