1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Industrial I/O driver for Microchip digital potentiometers
4 * Copyright (c) 2015 Axentia Technologies AB
5 * Author: Peter Rosin <peda@axentia.se>
6 *
7 * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
8 *
9 * DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address
10 * mcp4531 1 129 5, 10, 50, 100 010111x
11 * mcp4532 1 129 5, 10, 50, 100 01011xx
12 * mcp4541 1 129 5, 10, 50, 100 010111x
13 * mcp4542 1 129 5, 10, 50, 100 01011xx
14 * mcp4551 1 257 5, 10, 50, 100 010111x
15 * mcp4552 1 257 5, 10, 50, 100 01011xx
16 * mcp4561 1 257 5, 10, 50, 100 010111x
17 * mcp4562 1 257 5, 10, 50, 100 01011xx
18 * mcp4631 2 129 5, 10, 50, 100 0101xxx
19 * mcp4632 2 129 5, 10, 50, 100 01011xx
20 * mcp4641 2 129 5, 10, 50, 100 0101xxx
21 * mcp4642 2 129 5, 10, 50, 100 01011xx
22 * mcp4651 2 257 5, 10, 50, 100 0101xxx
23 * mcp4652 2 257 5, 10, 50, 100 01011xx
24 * mcp4661 2 257 5, 10, 50, 100 0101xxx
25 * mcp4662 2 257 5, 10, 50, 100 01011xx
26 */
27
28 #include <linux/module.h>
29 #include <linux/i2c.h>
30 #include <linux/err.h>
31 #include <linux/mod_devicetable.h>
32 #include <linux/property.h>
33
34 #include <linux/iio/iio.h>
35
36 struct mcp4531_cfg {
37 int wipers;
38 int avail[3];
39 int kohms;
40 };
41
42 enum mcp4531_type {
43 MCP453x_502,
44 MCP453x_103,
45 MCP453x_503,
46 MCP453x_104,
47 MCP454x_502,
48 MCP454x_103,
49 MCP454x_503,
50 MCP454x_104,
51 MCP455x_502,
52 MCP455x_103,
53 MCP455x_503,
54 MCP455x_104,
55 MCP456x_502,
56 MCP456x_103,
57 MCP456x_503,
58 MCP456x_104,
59 MCP463x_502,
60 MCP463x_103,
61 MCP463x_503,
62 MCP463x_104,
63 MCP464x_502,
64 MCP464x_103,
65 MCP464x_503,
66 MCP464x_104,
67 MCP465x_502,
68 MCP465x_103,
69 MCP465x_503,
70 MCP465x_104,
71 MCP466x_502,
72 MCP466x_103,
73 MCP466x_503,
74 MCP466x_104,
75 };
76
77 static const struct mcp4531_cfg mcp4531_cfg[] = {
78 [MCP453x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 5, },
79 [MCP453x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 10, },
80 [MCP453x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 50, },
81 [MCP453x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
82 [MCP454x_502] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 5, },
83 [MCP454x_103] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 10, },
84 [MCP454x_503] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 50, },
85 [MCP454x_104] = { .wipers = 1, .avail = { 0, 1, 128 }, .kohms = 100, },
86 [MCP455x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 5, },
87 [MCP455x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 10, },
88 [MCP455x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 50, },
89 [MCP455x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
90 [MCP456x_502] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 5, },
91 [MCP456x_103] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 10, },
92 [MCP456x_503] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 50, },
93 [MCP456x_104] = { .wipers = 1, .avail = { 0, 1, 256 }, .kohms = 100, },
94 [MCP463x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 5, },
95 [MCP463x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 10, },
96 [MCP463x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 50, },
97 [MCP463x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
98 [MCP464x_502] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 5, },
99 [MCP464x_103] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 10, },
100 [MCP464x_503] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 50, },
101 [MCP464x_104] = { .wipers = 2, .avail = { 0, 1, 128 }, .kohms = 100, },
102 [MCP465x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 5, },
103 [MCP465x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 10, },
104 [MCP465x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 50, },
105 [MCP465x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
106 [MCP466x_502] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 5, },
107 [MCP466x_103] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 10, },
108 [MCP466x_503] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 50, },
109 [MCP466x_104] = { .wipers = 2, .avail = { 0, 1, 256 }, .kohms = 100, },
110 };
111
112 #define MCP4531_WRITE (0 << 2)
113 #define MCP4531_INCR (1 << 2)
114 #define MCP4531_DECR (2 << 2)
115 #define MCP4531_READ (3 << 2)
116
117 #define MCP4531_WIPER_SHIFT (4)
118
119 struct mcp4531_data {
120 struct i2c_client *client;
121 const struct mcp4531_cfg *cfg;
122 };
123
124 #define MCP4531_CHANNEL(ch) { \
125 .type = IIO_RESISTANCE, \
126 .indexed = 1, \
127 .output = 1, \
128 .channel = (ch), \
129 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
130 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
131 .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW), \
132 }
133
134 static const struct iio_chan_spec mcp4531_channels[] = {
135 MCP4531_CHANNEL(0),
136 MCP4531_CHANNEL(1),
137 };
138
mcp4531_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)139 static int mcp4531_read_raw(struct iio_dev *indio_dev,
140 struct iio_chan_spec const *chan,
141 int *val, int *val2, long mask)
142 {
143 struct mcp4531_data *data = iio_priv(indio_dev);
144 int address = chan->channel << MCP4531_WIPER_SHIFT;
145 s32 ret;
146
147 switch (mask) {
148 case IIO_CHAN_INFO_RAW:
149 ret = i2c_smbus_read_word_swapped(data->client,
150 MCP4531_READ | address);
151 if (ret < 0)
152 return ret;
153 *val = ret;
154 return IIO_VAL_INT;
155 case IIO_CHAN_INFO_SCALE:
156 *val = 1000 * data->cfg->kohms;
157 *val2 = data->cfg->avail[2];
158 return IIO_VAL_FRACTIONAL;
159 }
160
161 return -EINVAL;
162 }
163
mcp4531_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)164 static int mcp4531_read_avail(struct iio_dev *indio_dev,
165 struct iio_chan_spec const *chan,
166 const int **vals, int *type, int *length,
167 long mask)
168 {
169 struct mcp4531_data *data = iio_priv(indio_dev);
170
171 switch (mask) {
172 case IIO_CHAN_INFO_RAW:
173 *length = ARRAY_SIZE(data->cfg->avail);
174 *vals = data->cfg->avail;
175 *type = IIO_VAL_INT;
176 return IIO_AVAIL_RANGE;
177 }
178
179 return -EINVAL;
180 }
181
mcp4531_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)182 static int mcp4531_write_raw(struct iio_dev *indio_dev,
183 struct iio_chan_spec const *chan,
184 int val, int val2, long mask)
185 {
186 struct mcp4531_data *data = iio_priv(indio_dev);
187 int address = chan->channel << MCP4531_WIPER_SHIFT;
188
189 switch (mask) {
190 case IIO_CHAN_INFO_RAW:
191 if (val > data->cfg->avail[2] || val < 0)
192 return -EINVAL;
193 break;
194 default:
195 return -EINVAL;
196 }
197
198 return i2c_smbus_write_byte_data(data->client,
199 MCP4531_WRITE | address | (val >> 8),
200 val & 0xff);
201 }
202
203 static const struct iio_info mcp4531_info = {
204 .read_raw = mcp4531_read_raw,
205 .read_avail = mcp4531_read_avail,
206 .write_raw = mcp4531_write_raw,
207 };
208
209 #define MCP4531_ID_TABLE(_name, cfg) { \
210 .name = _name, \
211 .driver_data = (kernel_ulong_t)&mcp4531_cfg[cfg], \
212 }
213
214 static const struct i2c_device_id mcp4531_id[] = {
215 MCP4531_ID_TABLE("mcp4531-502", MCP453x_502),
216 MCP4531_ID_TABLE("mcp4531-103", MCP453x_103),
217 MCP4531_ID_TABLE("mcp4531-503", MCP453x_503),
218 MCP4531_ID_TABLE("mcp4531-104", MCP453x_104),
219 MCP4531_ID_TABLE("mcp4532-502", MCP453x_502),
220 MCP4531_ID_TABLE("mcp4532-103", MCP453x_103),
221 MCP4531_ID_TABLE("mcp4532-503", MCP453x_503),
222 MCP4531_ID_TABLE("mcp4532-104", MCP453x_104),
223 MCP4531_ID_TABLE("mcp4541-502", MCP454x_502),
224 MCP4531_ID_TABLE("mcp4541-103", MCP454x_103),
225 MCP4531_ID_TABLE("mcp4541-503", MCP454x_503),
226 MCP4531_ID_TABLE("mcp4541-104", MCP454x_104),
227 MCP4531_ID_TABLE("mcp4542-502", MCP454x_502),
228 MCP4531_ID_TABLE("mcp4542-103", MCP454x_103),
229 MCP4531_ID_TABLE("mcp4542-503", MCP454x_503),
230 MCP4531_ID_TABLE("mcp4542-104", MCP454x_104),
231 MCP4531_ID_TABLE("mcp4551-502", MCP455x_502),
232 MCP4531_ID_TABLE("mcp4551-103", MCP455x_103),
233 MCP4531_ID_TABLE("mcp4551-503", MCP455x_503),
234 MCP4531_ID_TABLE("mcp4551-104", MCP455x_104),
235 MCP4531_ID_TABLE("mcp4552-502", MCP455x_502),
236 MCP4531_ID_TABLE("mcp4552-103", MCP455x_103),
237 MCP4531_ID_TABLE("mcp4552-503", MCP455x_503),
238 MCP4531_ID_TABLE("mcp4552-104", MCP455x_104),
239 MCP4531_ID_TABLE("mcp4561-502", MCP456x_502),
240 MCP4531_ID_TABLE("mcp4561-103", MCP456x_103),
241 MCP4531_ID_TABLE("mcp4561-503", MCP456x_503),
242 MCP4531_ID_TABLE("mcp4561-104", MCP456x_104),
243 MCP4531_ID_TABLE("mcp4562-502", MCP456x_502),
244 MCP4531_ID_TABLE("mcp4562-103", MCP456x_103),
245 MCP4531_ID_TABLE("mcp4562-503", MCP456x_503),
246 MCP4531_ID_TABLE("mcp4562-104", MCP456x_104),
247 MCP4531_ID_TABLE("mcp4631-502", MCP463x_502),
248 MCP4531_ID_TABLE("mcp4631-103", MCP463x_103),
249 MCP4531_ID_TABLE("mcp4631-503", MCP463x_503),
250 MCP4531_ID_TABLE("mcp4631-104", MCP463x_104),
251 MCP4531_ID_TABLE("mcp4632-502", MCP463x_502),
252 MCP4531_ID_TABLE("mcp4632-103", MCP463x_103),
253 MCP4531_ID_TABLE("mcp4632-503", MCP463x_503),
254 MCP4531_ID_TABLE("mcp4632-104", MCP463x_104),
255 MCP4531_ID_TABLE("mcp4641-502", MCP464x_502),
256 MCP4531_ID_TABLE("mcp4641-103", MCP464x_103),
257 MCP4531_ID_TABLE("mcp4641-503", MCP464x_503),
258 MCP4531_ID_TABLE("mcp4641-104", MCP464x_104),
259 MCP4531_ID_TABLE("mcp4642-502", MCP464x_502),
260 MCP4531_ID_TABLE("mcp4642-103", MCP464x_103),
261 MCP4531_ID_TABLE("mcp4642-503", MCP464x_503),
262 MCP4531_ID_TABLE("mcp4642-104", MCP464x_104),
263 MCP4531_ID_TABLE("mcp4651-502", MCP465x_502),
264 MCP4531_ID_TABLE("mcp4651-103", MCP465x_103),
265 MCP4531_ID_TABLE("mcp4651-503", MCP465x_503),
266 MCP4531_ID_TABLE("mcp4651-104", MCP465x_104),
267 MCP4531_ID_TABLE("mcp4652-502", MCP465x_502),
268 MCP4531_ID_TABLE("mcp4652-103", MCP465x_103),
269 MCP4531_ID_TABLE("mcp4652-503", MCP465x_503),
270 MCP4531_ID_TABLE("mcp4652-104", MCP465x_104),
271 MCP4531_ID_TABLE("mcp4661-502", MCP466x_502),
272 MCP4531_ID_TABLE("mcp4661-103", MCP466x_103),
273 MCP4531_ID_TABLE("mcp4661-503", MCP466x_503),
274 MCP4531_ID_TABLE("mcp4661-104", MCP466x_104),
275 MCP4531_ID_TABLE("mcp4662-502", MCP466x_502),
276 MCP4531_ID_TABLE("mcp4662-103", MCP466x_103),
277 MCP4531_ID_TABLE("mcp4662-503", MCP466x_503),
278 MCP4531_ID_TABLE("mcp4662-104", MCP466x_104),
279 { /* sentinel */ }
280 };
281 MODULE_DEVICE_TABLE(i2c, mcp4531_id);
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
mcp4531_probe(struct i2c_client * client)357 static int mcp4531_probe(struct i2c_client *client)
358 {
359 struct device *dev = &client->dev;
360 struct mcp4531_data *data;
361 struct iio_dev *indio_dev;
362
363 if (!i2c_check_functionality(client->adapter,
364 I2C_FUNC_SMBUS_WORD_DATA)) {
365 dev_err(dev, "SMBUS Word Data not supported\n");
366 return -EOPNOTSUPP;
367 }
368
369 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
370 if (!indio_dev)
371 return -ENOMEM;
372 data = iio_priv(indio_dev);
373 i2c_set_clientdata(client, indio_dev);
374 data->client = client;
375
376 data->cfg = i2c_get_match_data(client);
377
378 indio_dev->info = &mcp4531_info;
379 indio_dev->channels = mcp4531_channels;
380 indio_dev->num_channels = data->cfg->wipers;
381 indio_dev->name = client->name;
382
383 return devm_iio_device_register(dev, indio_dev);
384 }
385
386 static struct i2c_driver mcp4531_driver = {
387 .driver = {
388 .name = "mcp4531",
389 .of_match_table = mcp4531_of_match,
390 },
391 .probe = mcp4531_probe,
392 .id_table = mcp4531_id,
393 };
394
395 module_i2c_driver(mcp4531_driver);
396
397 MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
398 MODULE_DESCRIPTION("MCP4531 digital potentiometer");
399 MODULE_LICENSE("GPL v2");
400