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>
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
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
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
48 * See Documentation/misc-devices/ad525x_dpot.txt for more info.
50 * derived from ad5258.c
51 * Copyright (c) 2009 Cyber Switching, Inc.
52 * Author: Chris Verges <chrisv@cyberswitching.com>
54 * derived from ad5252.c
55 * Copyright (c) 2006 Michael Hennerich <hennerich@blackfin.uclinux.org>
57 * Licensed under the GPL-2 or later.
60 #include <linux/module.h>
61 #include <linux/device.h>
62 #include <linux/kernel.h>
63 #include <linux/init.h>
64 #include <linux/delay.h>
65 #include <linux/slab.h>
67 #define DRIVER_VERSION "0.2"
69 #include "ad525x_dpot.h"
72 * Client data (each client gets its own)
76 struct ad_dpot_bus_data bdata;
77 struct mutex update_lock;
87 static inline int dpot_read_d8(struct dpot_data *dpot)
89 return dpot->bdata.bops->read_d8(dpot->bdata.client);
92 static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg)
94 return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg);
97 static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg)
99 return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg);
102 static inline int dpot_write_d8(struct dpot_data *dpot, u8 val)
104 return dpot->bdata.bops->write_d8(dpot->bdata.client, val);
107 static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val)
109 return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val);
112 static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val)
114 return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val);
117 static s32 dpot_read_spi(struct dpot_data *dpot, u8 reg)
121 if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
123 if (dpot->feat & F_RDACS_WONLY)
124 return dpot->rdac_cache[reg & DPOT_RDAC_MASK];
126 if (dpot->uid == DPOT_UID(AD5291_ID) ||
127 dpot->uid == DPOT_UID(AD5292_ID) ||
128 dpot->uid == DPOT_UID(AD5293_ID))
129 return dpot_read_r8d8(dpot,
130 DPOT_AD5291_READ_RDAC << 2);
132 ctrl = DPOT_SPI_READ_RDAC;
133 } else if (reg & DPOT_ADDR_EEPROM) {
134 ctrl = DPOT_SPI_READ_EEPROM;
137 if (dpot->feat & F_SPI_16BIT)
138 return dpot_read_r8d8(dpot, ctrl);
139 else if (dpot->feat & F_SPI_24BIT)
140 return dpot_read_r8d16(dpot, ctrl);
145 static s32 dpot_read_i2c(struct dpot_data *dpot, u8 reg)
149 case DPOT_UID(AD5246_ID):
150 case DPOT_UID(AD5247_ID):
151 return dpot_read_d8(dpot);
152 case DPOT_UID(AD5245_ID):
153 case DPOT_UID(AD5241_ID):
154 case DPOT_UID(AD5242_ID):
155 case DPOT_UID(AD5243_ID):
156 case DPOT_UID(AD5248_ID):
157 ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
158 0 : DPOT_AD5291_RDAC_AB;
159 return dpot_read_r8d8(dpot, ctrl);
161 if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
162 return dpot_read_r8d16(dpot, (reg & 0xF8) |
165 return dpot_read_r8d8(dpot, reg);
169 static s32 dpot_read(struct dpot_data *dpot, u8 reg)
171 if (dpot->feat & F_SPI)
172 return dpot_read_spi(dpot, reg);
174 return dpot_read_i2c(dpot, reg);
177 static s32 dpot_write_spi(struct dpot_data *dpot, u8 reg, u16 value)
181 if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
182 if (dpot->feat & F_RDACS_WONLY)
183 dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value;
185 if (dpot->feat & F_AD_APPDATA) {
186 if (dpot->feat & F_SPI_8BIT) {
187 val = ((reg & DPOT_RDAC_MASK) <<
188 DPOT_MAX_POS(dpot->devid)) |
190 return dpot_write_d8(dpot, val);
191 } else if (dpot->feat & F_SPI_16BIT) {
192 val = ((reg & DPOT_RDAC_MASK) <<
193 DPOT_MAX_POS(dpot->devid)) |
195 return dpot_write_r8d8(dpot, val >> 8,
200 if (dpot->uid == DPOT_UID(AD5291_ID) ||
201 dpot->uid == DPOT_UID(AD5292_ID) ||
202 dpot->uid == DPOT_UID(AD5293_ID))
203 return dpot_write_r8d8(dpot,
204 (DPOT_AD5291_RDAC << 2) |
205 (value >> 8), value & 0xFF);
207 val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK);
209 } else if (reg & DPOT_ADDR_EEPROM) {
210 val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK);
211 } else if (reg & DPOT_ADDR_CMD) {
213 case DPOT_DEC_ALL_6DB:
214 val = DPOT_SPI_DEC_ALL_6DB;
216 case DPOT_INC_ALL_6DB:
217 val = DPOT_SPI_INC_ALL_6DB;
220 val = DPOT_SPI_DEC_ALL;
223 val = DPOT_SPI_INC_ALL;
229 if (dpot->feat & F_SPI_16BIT)
230 return dpot_write_r8d8(dpot, val, value);
231 else if (dpot->feat & F_SPI_24BIT)
232 return dpot_write_r8d16(dpot, val, value);
237 static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
239 /* Only write the instruction byte for certain commands */
243 case DPOT_UID(AD5246_ID):
244 case DPOT_UID(AD5247_ID):
245 return dpot_write_d8(dpot, value);
248 case DPOT_UID(AD5245_ID):
249 case DPOT_UID(AD5241_ID):
250 case DPOT_UID(AD5242_ID):
251 case DPOT_UID(AD5243_ID):
252 case DPOT_UID(AD5248_ID):
253 ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ? 0 : DPOT_AD5291_RDAC_AB;
254 return dpot_write_r8d8(dpot, ctrl, value);
259 if (reg & DPOT_ADDR_CMD)
260 return dpot_write_d8(dpot, reg);
262 if (dpot->max_pos > 256)
263 return dpot_write_r8d16(dpot, (reg & 0xF8) |
264 ((reg & 0x7) << 1), value);
266 /* All other registers require instruction + data bytes */
267 return dpot_write_r8d8(dpot, reg, value);
272 static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
274 if (dpot->feat & F_SPI)
275 return dpot_write_spi(dpot, reg, value);
277 return dpot_write_i2c(dpot, reg, value);
280 /* sysfs functions */
282 static ssize_t sysfs_show_reg(struct device *dev,
283 struct device_attribute *attr,
286 struct dpot_data *data = dev_get_drvdata(dev);
289 mutex_lock(&data->update_lock);
290 value = dpot_read(data, reg);
291 mutex_unlock(&data->update_lock);
296 * Let someone else deal with converting this ...
297 * the tolerance is a two-byte value where the MSB
298 * is a sign + integer value, and the LSB is a
299 * decimal value. See page 18 of the AD5258
300 * datasheet (Rev. A) for more details.
303 if (reg & DPOT_REG_TOL)
304 return sprintf(buf, "0x%04x\n", value & 0xFFFF);
306 return sprintf(buf, "%u\n", value & data->rdac_mask);
309 static ssize_t sysfs_set_reg(struct device *dev,
310 struct device_attribute *attr,
311 const char *buf, size_t count, u32 reg)
313 struct dpot_data *data = dev_get_drvdata(dev);
317 err = strict_strtoul(buf, 10, &value);
321 if (value > data->rdac_mask)
322 value = data->rdac_mask;
324 mutex_lock(&data->update_lock);
325 dpot_write(data, reg, value);
326 if (reg & DPOT_ADDR_EEPROM)
327 msleep(26); /* Sleep while the EEPROM updates */
328 mutex_unlock(&data->update_lock);
333 static ssize_t sysfs_do_cmd(struct device *dev,
334 struct device_attribute *attr,
335 const char *buf, size_t count, u32 reg)
337 struct dpot_data *data = dev_get_drvdata(dev);
339 mutex_lock(&data->update_lock);
340 dpot_write(data, reg, 0);
341 mutex_unlock(&data->update_lock);
346 /* ------------------------------------------------------------------------- */
348 #define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
349 show_##_name(struct device *dev, \
350 struct device_attribute *attr, char *buf) \
352 return sysfs_show_reg(dev, attr, buf, _reg); \
355 #define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
356 set_##_name(struct device *dev, \
357 struct device_attribute *attr, \
358 const char *buf, size_t count) \
360 return sysfs_set_reg(dev, attr, buf, count, _reg); \
363 #define DPOT_DEVICE_SHOW_SET(name, reg) \
364 DPOT_DEVICE_SHOW(name, reg) \
365 DPOT_DEVICE_SET(name, reg) \
366 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name);
368 #define DPOT_DEVICE_SHOW_ONLY(name, reg) \
369 DPOT_DEVICE_SHOW(name, reg) \
370 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL);
372 DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
373 DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
374 DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
376 DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
377 DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
378 DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
380 DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
381 DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
382 DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
384 DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
385 DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
386 DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
388 DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
389 DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
390 DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
392 DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
393 DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
394 DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
396 static const struct attribute *dpot_attrib_wipers[] = {
397 &dev_attr_rdac0.attr,
398 &dev_attr_rdac1.attr,
399 &dev_attr_rdac2.attr,
400 &dev_attr_rdac3.attr,
401 &dev_attr_rdac4.attr,
402 &dev_attr_rdac5.attr,
406 static const struct attribute *dpot_attrib_eeprom[] = {
407 &dev_attr_eeprom0.attr,
408 &dev_attr_eeprom1.attr,
409 &dev_attr_eeprom2.attr,
410 &dev_attr_eeprom3.attr,
411 &dev_attr_eeprom4.attr,
412 &dev_attr_eeprom5.attr,
416 static const struct attribute *dpot_attrib_tolerance[] = {
417 &dev_attr_tolerance0.attr,
418 &dev_attr_tolerance1.attr,
419 &dev_attr_tolerance2.attr,
420 &dev_attr_tolerance3.attr,
421 &dev_attr_tolerance4.attr,
422 &dev_attr_tolerance5.attr,
426 /* ------------------------------------------------------------------------- */
428 #define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
429 set_##_name(struct device *dev, \
430 struct device_attribute *attr, \
431 const char *buf, size_t count) \
433 return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
435 static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name);
437 DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
438 DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
439 DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
440 DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);
442 static struct attribute *ad525x_attributes_commands[] = {
443 &dev_attr_inc_all.attr,
444 &dev_attr_dec_all.attr,
445 &dev_attr_inc_all_6db.attr,
446 &dev_attr_dec_all_6db.attr,
450 static const struct attribute_group ad525x_group_commands = {
451 .attrs = ad525x_attributes_commands,
454 __devinit int ad_dpot_add_files(struct device *dev,
455 unsigned features, unsigned rdac)
457 int err = sysfs_create_file(&dev->kobj,
458 dpot_attrib_wipers[rdac]);
459 if (features & F_CMD_EEP)
460 err |= sysfs_create_file(&dev->kobj,
461 dpot_attrib_eeprom[rdac]);
462 if (features & F_CMD_TOL)
463 err |= sysfs_create_file(&dev->kobj,
464 dpot_attrib_tolerance[rdac]);
467 dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
473 inline void ad_dpot_remove_files(struct device *dev,
474 unsigned features, unsigned rdac)
476 sysfs_remove_file(&dev->kobj,
477 dpot_attrib_wipers[rdac]);
478 if (features & F_CMD_EEP)
479 sysfs_remove_file(&dev->kobj,
480 dpot_attrib_eeprom[rdac]);
481 if (features & F_CMD_TOL)
482 sysfs_remove_file(&dev->kobj,
483 dpot_attrib_tolerance[rdac]);
486 __devinit int ad_dpot_probe(struct device *dev,
487 struct ad_dpot_bus_data *bdata, const struct ad_dpot_id *id)
490 struct dpot_data *data;
493 data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
499 dev_set_drvdata(dev, data);
500 mutex_init(&data->update_lock);
502 data->bdata = *bdata;
503 data->devid = id->devid;
505 data->max_pos = 1 << DPOT_MAX_POS(data->devid);
506 data->rdac_mask = data->max_pos - 1;
507 data->feat = DPOT_FEAT(data->devid);
508 data->uid = DPOT_UID(data->devid);
509 data->wipers = DPOT_WIPERS(data->devid);
511 for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++)
512 if (data->wipers & (1 << i)) {
513 err = ad_dpot_add_files(dev, data->feat, i);
515 goto exit_remove_files;
516 /* power-up midscale */
517 if (data->feat & F_RDACS_WONLY)
518 data->rdac_cache[i] = data->max_pos / 2;
521 if (data->feat & F_CMD_INC)
522 err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);
525 dev_err(dev, "failed to register sysfs hooks\n");
529 dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
530 id->name, data->max_pos);
535 for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++)
536 if (data->wipers & (1 << i))
537 ad_dpot_remove_files(dev, data->feat, i);
541 dev_set_drvdata(dev, NULL);
543 dev_err(dev, "failed to create client for %s ID 0x%lX\n",
544 id->name, id->devid);
547 EXPORT_SYMBOL(ad_dpot_probe);
549 __devexit int ad_dpot_remove(struct device *dev)
551 struct dpot_data *data = dev_get_drvdata(dev);
554 for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++)
555 if (data->wipers & (1 << i))
556 ad_dpot_remove_files(dev, data->feat, i);
562 EXPORT_SYMBOL(ad_dpot_remove);
565 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
566 "Michael Hennerich <hennerich@blackfin.uclinux.org>");
567 MODULE_DESCRIPTION("Digital potentiometer driver");
568 MODULE_LICENSE("GPL");
569 MODULE_VERSION(DRIVER_VERSION);