xref: /linux/drivers/iio/potentiometer/mcp4531.c (revision a1c613ae4c322ddd58d5a8539dbfba2a0380a8c0) 
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