1 /*
2 * Industrial I/O driver for Microchip digital potentiometers
3 * Copyright (c) 2015 Axentia Technologies AB
4 * Author: Peter Rosin <peda@axentia.se>
5 *
6 * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
7 *
8 * DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address
9 * mcp4531 1 129 5, 10, 50, 100 010111x
10 * mcp4532 1 129 5, 10, 50, 100 01011xx
11 * mcp4541 1 129 5, 10, 50, 100 010111x
12 * mcp4542 1 129 5, 10, 50, 100 01011xx
13 * mcp4551 1 257 5, 10, 50, 100 010111x
14 * mcp4552 1 257 5, 10, 50, 100 01011xx
15 * mcp4561 1 257 5, 10, 50, 100 010111x
16 * mcp4562 1 257 5, 10, 50, 100 01011xx
17 * mcp4631 2 129 5, 10, 50, 100 0101xxx
18 * mcp4632 2 129 5, 10, 50, 100 01011xx
19 * mcp4641 2 129 5, 10, 50, 100 0101xxx
20 * mcp4642 2 129 5, 10, 50, 100 01011xx
21 * mcp4651 2 257 5, 10, 50, 100 0101xxx
22 * mcp4652 2 257 5, 10, 50, 100 01011xx
23 * mcp4661 2 257 5, 10, 50, 100 0101xxx
24 * mcp4662 2 257 5, 10, 50, 100 01011xx
25 *
26 * This program is free software; you can redistribute it and/or modify it
27 * under the terms of the GNU General Public License version 2 as published by
28 * the Free Software Foundation.
29 */
30
31 #include <linux/module.h>
32 #include <linux/i2c.h>
33 #include <linux/err.h>
34 #include <linux/of.h>
35 #include <linux/of_device.h>
36
37 #include <linux/iio/iio.h>
38
39 struct mcp4531_cfg {
40 int wipers;
41 int avail[3];
42 int kohms;
43 };
44
45 enum mcp4531_type {
46 MCP453x_502,
47 MCP453x_103,
48 MCP453x_503,
49 MCP453x_104,
50 MCP454x_502,
51 MCP454x_103,
52 MCP454x_503,
53 MCP454x_104,
54 MCP455x_502,
55 MCP455x_103,
56 MCP455x_503,
57 MCP455x_104,
58 MCP456x_502,
59 MCP456x_103,
60 MCP456x_503,
61 MCP456x_104,
62 MCP463x_502,
63 MCP463x_103,
64 MCP463x_503,
65 MCP463x_104,
66 MCP464x_502,
67 MCP464x_103,
68 MCP464x_503,
69 MCP464x_104,
70 MCP465x_502,
71 MCP465x_103,
72 MCP465x_503,
73 MCP465x_104,
74 MCP466x_502,
75 MCP466x_103,
76 MCP466x_503,
77 MCP466x_104,
78 };
79
80 static const struct mcp4531_cfg mcp4531_cfg[] = {
81 [MCP453x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 5, },
82 [MCP453x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 10, },
83 [MCP453x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 50, },
84 [MCP453x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
85 [MCP454x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 5, },
86 [MCP454x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 10, },
87 [MCP454x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 50, },
88 [MCP454x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
89 [MCP455x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 5, },
90 [MCP455x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 10, },
91 [MCP455x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 50, },
92 [MCP455x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
93 [MCP456x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 5, },
94 [MCP456x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 10, },
95 [MCP456x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 50, },
96 [MCP456x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
97 [MCP463x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 5, },
98 [MCP463x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 10, },
99 [MCP463x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 50, },
100 [MCP463x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
101 [MCP464x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 5, },
102 [MCP464x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 10, },
103 [MCP464x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 50, },
104 [MCP464x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
105 [MCP465x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 5, },
106 [MCP465x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 10, },
107 [MCP465x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 50, },
108 [MCP465x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
109 [MCP466x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 5, },
110 [MCP466x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 10, },
111 [MCP466x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 50, },
112 [MCP466x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
113 };
114
115 #define MCP4531_WRITE (0 << 2)
116 #define MCP4531_INCR (1 << 2)
117 #define MCP4531_DECR (2 << 2)
118 #define MCP4531_READ (3 << 2)
119
120 #define MCP4531_WIPER_SHIFT (4)
121
122 struct mcp4531_data {
123 struct i2c_client *client;
124 const struct mcp4531_cfg *cfg;
125 };
126
127 #define MCP4531_CHANNEL(ch) { \
128 .type = IIO_RESISTANCE, \
129 .indexed = 1, \
130 .output = 1, \
131 .channel = (ch), \
132 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
133 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
134 .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW), \
135 }
136
137 static const struct iio_chan_spec mcp4531_channels[] = {
138 MCP4531_CHANNEL(0),
139 MCP4531_CHANNEL(1),
140 };
141
mcp4531_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)142 static int mcp4531_read_raw(struct iio_dev *indio_dev,
143 struct iio_chan_spec const *chan,
144 int *val, int *val2, long mask)
145 {
146 struct mcp4531_data *data = iio_priv(indio_dev);
147 int address = chan->channel << MCP4531_WIPER_SHIFT;
148 s32 ret;
149
150 switch (mask) {
151 case IIO_CHAN_INFO_RAW:
152 ret = i2c_smbus_read_word_swapped(data->client,
153 MCP4531_READ | address);
154 if (ret < 0)
155 return ret;
156 *val = ret;
157 return IIO_VAL_INT;
158 case IIO_CHAN_INFO_SCALE:
159 *val = 1000 * data->cfg->kohms;
160 *val2 = data->cfg->avail[2];
161 return IIO_VAL_FRACTIONAL;
162 }
163
164 return -EINVAL;
165 }
166
mcp4531_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)167 static int mcp4531_read_avail(struct iio_dev *indio_dev,
168 struct iio_chan_spec const *chan,
169 const int **vals, int *type, int *length,
170 long mask)
171 {
172 struct mcp4531_data *data = iio_priv(indio_dev);
173
174 switch (mask) {
175 case IIO_CHAN_INFO_RAW:
176 *length = ARRAY_SIZE(data->cfg->avail);
177 *vals = data->cfg->avail;
178 *type = IIO_VAL_INT;
179 return IIO_AVAIL_RANGE;
180 }
181
182 return -EINVAL;
183 }
184
mcp4531_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)185 static int mcp4531_write_raw(struct iio_dev *indio_dev,
186 struct iio_chan_spec const *chan,
187 int val, int val2, long mask)
188 {
189 struct mcp4531_data *data = iio_priv(indio_dev);
190 int address = chan->channel << MCP4531_WIPER_SHIFT;
191
192 switch (mask) {
193 case IIO_CHAN_INFO_RAW:
194 if (val > data->cfg->avail[2] || val < 0)
195 return -EINVAL;
196 break;
197 default:
198 return -EINVAL;
199 }
200
201 return i2c_smbus_write_byte_data(data->client,
202 MCP4531_WRITE | address | (val >> 8),
203 val & 0xff);
204 }
205
206 static const struct iio_info mcp4531_info = {
207 .read_raw = mcp4531_read_raw,
208 .read_avail = mcp4531_read_avail,
209 .write_raw = mcp4531_write_raw,
210 };
211
212 static const struct i2c_device_id mcp4531_id[] = {
213 { "mcp4531-502", MCP453x_502 },
214 { "mcp4531-103", MCP453x_103 },
215 { "mcp4531-503", MCP453x_503 },
216 { "mcp4531-104", MCP453x_104 },
217 { "mcp4532-502", MCP453x_502 },
218 { "mcp4532-103", MCP453x_103 },
219 { "mcp4532-503", MCP453x_503 },
220 { "mcp4532-104", MCP453x_104 },
221 { "mcp4541-502", MCP454x_502 },
222 { "mcp4541-103", MCP454x_103 },
223 { "mcp4541-503", MCP454x_503 },
224 { "mcp4541-104", MCP454x_104 },
225 { "mcp4542-502", MCP454x_502 },
226 { "mcp4542-103", MCP454x_103 },
227 { "mcp4542-503", MCP454x_503 },
228 { "mcp4542-104", MCP454x_104 },
229 { "mcp4551-502", MCP455x_502 },
230 { "mcp4551-103", MCP455x_103 },
231 { "mcp4551-503", MCP455x_503 },
232 { "mcp4551-104", MCP455x_104 },
233 { "mcp4552-502", MCP455x_502 },
234 { "mcp4552-103", MCP455x_103 },
235 { "mcp4552-503", MCP455x_503 },
236 { "mcp4552-104", MCP455x_104 },
237 { "mcp4561-502", MCP456x_502 },
238 { "mcp4561-103", MCP456x_103 },
239 { "mcp4561-503", MCP456x_503 },
240 { "mcp4561-104", MCP456x_104 },
241 { "mcp4562-502", MCP456x_502 },
242 { "mcp4562-103", MCP456x_103 },
243 { "mcp4562-503", MCP456x_503 },
244 { "mcp4562-104", MCP456x_104 },
245 { "mcp4631-502", MCP463x_502 },
246 { "mcp4631-103", MCP463x_103 },
247 { "mcp4631-503", MCP463x_503 },
248 { "mcp4631-104", MCP463x_104 },
249 { "mcp4632-502", MCP463x_502 },
250 { "mcp4632-103", MCP463x_103 },
251 { "mcp4632-503", MCP463x_503 },
252 { "mcp4632-104", MCP463x_104 },
253 { "mcp4641-502", MCP464x_502 },
254 { "mcp4641-103", MCP464x_103 },
255 { "mcp4641-503", MCP464x_503 },
256 { "mcp4641-104", MCP464x_104 },
257 { "mcp4642-502", MCP464x_502 },
258 { "mcp4642-103", MCP464x_103 },
259 { "mcp4642-503", MCP464x_503 },
260 { "mcp4642-104", MCP464x_104 },
261 { "mcp4651-502", MCP465x_502 },
262 { "mcp4651-103", MCP465x_103 },
263 { "mcp4651-503", MCP465x_503 },
264 { "mcp4651-104", MCP465x_104 },
265 { "mcp4652-502", MCP465x_502 },
266 { "mcp4652-103", MCP465x_103 },
267 { "mcp4652-503", MCP465x_503 },
268 { "mcp4652-104", MCP465x_104 },
269 { "mcp4661-502", MCP466x_502 },
270 { "mcp4661-103", MCP466x_103 },
271 { "mcp4661-503", MCP466x_503 },
272 { "mcp4661-104", MCP466x_104 },
273 { "mcp4662-502", MCP466x_502 },
274 { "mcp4662-103", MCP466x_103 },
275 { "mcp4662-503", MCP466x_503 },
276 { "mcp4662-104", MCP466x_104 },
277 {}
278 };
279 MODULE_DEVICE_TABLE(i2c, mcp4531_id);
280
281 #ifdef CONFIG_OF
282
283 #define MCP4531_COMPATIBLE(of_compatible, cfg) { \
284 .compatible = of_compatible, \
285 .data = &mcp4531_cfg[cfg], \
286 }
287
288 static const struct of_device_id mcp4531_of_match[] = {
289 MCP4531_COMPATIBLE("microchip,mcp4531-502", MCP453x_502),
290 MCP4531_COMPATIBLE("microchip,mcp4531-103", MCP453x_103),
291 MCP4531_COMPATIBLE("microchip,mcp4531-503", MCP453x_503),
292 MCP4531_COMPATIBLE("microchip,mcp4531-104", MCP453x_104),
293 MCP4531_COMPATIBLE("microchip,mcp4532-502", MCP453x_502),
294 MCP4531_COMPATIBLE("microchip,mcp4532-103", MCP453x_103),
295 MCP4531_COMPATIBLE("microchip,mcp4532-503", MCP453x_503),
296 MCP4531_COMPATIBLE("microchip,mcp4532-104", MCP453x_104),
297 MCP4531_COMPATIBLE("microchip,mcp4541-502", MCP454x_502),
298 MCP4531_COMPATIBLE("microchip,mcp4541-103", MCP454x_103),
299 MCP4531_COMPATIBLE("microchip,mcp4541-503", MCP454x_503),
300 MCP4531_COMPATIBLE("microchip,mcp4541-104", MCP454x_104),
301 MCP4531_COMPATIBLE("microchip,mcp4542-502", MCP454x_502),
302 MCP4531_COMPATIBLE("microchip,mcp4542-103", MCP454x_103),
303 MCP4531_COMPATIBLE("microchip,mcp4542-503", MCP454x_503),
304 MCP4531_COMPATIBLE("microchip,mcp4542-104", MCP454x_104),
305 MCP4531_COMPATIBLE("microchip,mcp4551-502", MCP455x_502),
306 MCP4531_COMPATIBLE("microchip,mcp4551-103", MCP455x_103),
307 MCP4531_COMPATIBLE("microchip,mcp4551-503", MCP455x_503),
308 MCP4531_COMPATIBLE("microchip,mcp4551-104", MCP455x_104),
309 MCP4531_COMPATIBLE("microchip,mcp4552-502", MCP455x_502),
310 MCP4531_COMPATIBLE("microchip,mcp4552-103", MCP455x_103),
311 MCP4531_COMPATIBLE("microchip,mcp4552-503", MCP455x_503),
312 MCP4531_COMPATIBLE("microchip,mcp4552-104", MCP455x_104),
313 MCP4531_COMPATIBLE("microchip,mcp4561-502", MCP456x_502),
314 MCP4531_COMPATIBLE("microchip,mcp4561-103", MCP456x_103),
315 MCP4531_COMPATIBLE("microchip,mcp4561-503", MCP456x_503),
316 MCP4531_COMPATIBLE("microchip,mcp4561-104", MCP456x_104),
317 MCP4531_COMPATIBLE("microchip,mcp4562-502", MCP456x_502),
318 MCP4531_COMPATIBLE("microchip,mcp4562-103", MCP456x_103),
319 MCP4531_COMPATIBLE("microchip,mcp4562-503", MCP456x_503),
320 MCP4531_COMPATIBLE("microchip,mcp4562-104", MCP456x_104),
321 MCP4531_COMPATIBLE("microchip,mcp4631-502", MCP463x_502),
322 MCP4531_COMPATIBLE("microchip,mcp4631-103", MCP463x_103),
323 MCP4531_COMPATIBLE("microchip,mcp4631-503", MCP463x_503),
324 MCP4531_COMPATIBLE("microchip,mcp4631-104", MCP463x_104),
325 MCP4531_COMPATIBLE("microchip,mcp4632-502", MCP463x_502),
326 MCP4531_COMPATIBLE("microchip,mcp4632-103", MCP463x_103),
327 MCP4531_COMPATIBLE("microchip,mcp4632-503", MCP463x_503),
328 MCP4531_COMPATIBLE("microchip,mcp4632-104", MCP463x_104),
329 MCP4531_COMPATIBLE("microchip,mcp4641-502", MCP464x_502),
330 MCP4531_COMPATIBLE("microchip,mcp4641-103", MCP464x_103),
331 MCP4531_COMPATIBLE("microchip,mcp4641-503", MCP464x_503),
332 MCP4531_COMPATIBLE("microchip,mcp4641-104", MCP464x_104),
333 MCP4531_COMPATIBLE("microchip,mcp4642-502", MCP464x_502),
334 MCP4531_COMPATIBLE("microchip,mcp4642-103", MCP464x_103),
335 MCP4531_COMPATIBLE("microchip,mcp4642-503", MCP464x_503),
336 MCP4531_COMPATIBLE("microchip,mcp4642-104", MCP464x_104),
337 MCP4531_COMPATIBLE("microchip,mcp4651-502", MCP465x_502),
338 MCP4531_COMPATIBLE("microchip,mcp4651-103", MCP465x_103),
339 MCP4531_COMPATIBLE("microchip,mcp4651-503", MCP465x_503),
340 MCP4531_COMPATIBLE("microchip,mcp4651-104", MCP465x_104),
341 MCP4531_COMPATIBLE("microchip,mcp4652-502", MCP465x_502),
342 MCP4531_COMPATIBLE("microchip,mcp4652-103", MCP465x_103),
343 MCP4531_COMPATIBLE("microchip,mcp4652-503", MCP465x_503),
344 MCP4531_COMPATIBLE("microchip,mcp4652-104", MCP465x_104),
345 MCP4531_COMPATIBLE("microchip,mcp4661-502", MCP466x_502),
346 MCP4531_COMPATIBLE("microchip,mcp4661-103", MCP466x_103),
347 MCP4531_COMPATIBLE("microchip,mcp4661-503", MCP466x_503),
348 MCP4531_COMPATIBLE("microchip,mcp4661-104", MCP466x_104),
349 MCP4531_COMPATIBLE("microchip,mcp4662-502", MCP466x_502),
350 MCP4531_COMPATIBLE("microchip,mcp4662-103", MCP466x_103),
351 MCP4531_COMPATIBLE("microchip,mcp4662-503", MCP466x_503),
352 MCP4531_COMPATIBLE("microchip,mcp4662-104", MCP466x_104),
353 { /* sentinel */ }
354 };
355 MODULE_DEVICE_TABLE(of, mcp4531_of_match);
356 #endif
357
mcp4531_probe(struct i2c_client * client)358 static int mcp4531_probe(struct i2c_client *client)
359 {
360 struct device *dev = &client->dev;
361 struct mcp4531_data *data;
362 struct iio_dev *indio_dev;
363 const struct of_device_id *match;
364
365 if (!i2c_check_functionality(client->adapter,
366 I2C_FUNC_SMBUS_WORD_DATA)) {
367 dev_err(dev, "SMBUS Word Data not supported\n");
368 return -EOPNOTSUPP;
369 }
370
371 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
372 if (!indio_dev)
373 return -ENOMEM;
374 data = iio_priv(indio_dev);
375 i2c_set_clientdata(client, indio_dev);
376 data->client = client;
377
378 match = of_match_device(of_match_ptr(mcp4531_of_match), dev);
379 if (match)
380 data->cfg = of_device_get_match_data(dev);
381 else
382 data->cfg = &mcp4531_cfg[i2c_match_id(mcp4531_id, client)->driver_data];
383
384 indio_dev->dev.parent = dev;
385 indio_dev->info = &mcp4531_info;
386 indio_dev->channels = mcp4531_channels;
387 indio_dev->num_channels = data->cfg->wipers;
388 indio_dev->name = client->name;
389
390 return devm_iio_device_register(dev, indio_dev);
391 }
392
393 static struct i2c_driver mcp4531_driver = {
394 .driver = {
395 .name = "mcp4531",
396 .of_match_table = of_match_ptr(mcp4531_of_match),
397 },
398 .probe_new = mcp4531_probe,
399 .id_table = mcp4531_id,
400 };
401
402 module_i2c_driver(mcp4531_driver);
403
404 MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
405 MODULE_DESCRIPTION("MCP4531 digital potentiometer");
406 MODULE_LICENSE("GPL");
407
