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
36struct mcp4531_cfg {
37	int wipers;
38	int avail[3];
39	int kohms;
40};
41
42enum 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
77static 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
119struct 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
134static const struct iio_chan_spec mcp4531_channels[] = {
135	MCP4531_CHANNEL(0),
136	MCP4531_CHANNEL(1),
137};
138
139static 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
164static 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
182static 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
203static 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
209static const struct i2c_device_id mcp4531_id[] = {
210	{ "mcp4531-502", MCP453x_502 },
211	{ "mcp4531-103", MCP453x_103 },
212	{ "mcp4531-503", MCP453x_503 },
213	{ "mcp4531-104", MCP453x_104 },
214	{ "mcp4532-502", MCP453x_502 },
215	{ "mcp4532-103", MCP453x_103 },
216	{ "mcp4532-503", MCP453x_503 },
217	{ "mcp4532-104", MCP453x_104 },
218	{ "mcp4541-502", MCP454x_502 },
219	{ "mcp4541-103", MCP454x_103 },
220	{ "mcp4541-503", MCP454x_503 },
221	{ "mcp4541-104", MCP454x_104 },
222	{ "mcp4542-502", MCP454x_502 },
223	{ "mcp4542-103", MCP454x_103 },
224	{ "mcp4542-503", MCP454x_503 },
225	{ "mcp4542-104", MCP454x_104 },
226	{ "mcp4551-502", MCP455x_502 },
227	{ "mcp4551-103", MCP455x_103 },
228	{ "mcp4551-503", MCP455x_503 },
229	{ "mcp4551-104", MCP455x_104 },
230	{ "mcp4552-502", MCP455x_502 },
231	{ "mcp4552-103", MCP455x_103 },
232	{ "mcp4552-503", MCP455x_503 },
233	{ "mcp4552-104", MCP455x_104 },
234	{ "mcp4561-502", MCP456x_502 },
235	{ "mcp4561-103", MCP456x_103 },
236	{ "mcp4561-503", MCP456x_503 },
237	{ "mcp4561-104", MCP456x_104 },
238	{ "mcp4562-502", MCP456x_502 },
239	{ "mcp4562-103", MCP456x_103 },
240	{ "mcp4562-503", MCP456x_503 },
241	{ "mcp4562-104", MCP456x_104 },
242	{ "mcp4631-502", MCP463x_502 },
243	{ "mcp4631-103", MCP463x_103 },
244	{ "mcp4631-503", MCP463x_503 },
245	{ "mcp4631-104", MCP463x_104 },
246	{ "mcp4632-502", MCP463x_502 },
247	{ "mcp4632-103", MCP463x_103 },
248	{ "mcp4632-503", MCP463x_503 },
249	{ "mcp4632-104", MCP463x_104 },
250	{ "mcp4641-502", MCP464x_502 },
251	{ "mcp4641-103", MCP464x_103 },
252	{ "mcp4641-503", MCP464x_503 },
253	{ "mcp4641-104", MCP464x_104 },
254	{ "mcp4642-502", MCP464x_502 },
255	{ "mcp4642-103", MCP464x_103 },
256	{ "mcp4642-503", MCP464x_503 },
257	{ "mcp4642-104", MCP464x_104 },
258	{ "mcp4651-502", MCP465x_502 },
259	{ "mcp4651-103", MCP465x_103 },
260	{ "mcp4651-503", MCP465x_503 },
261	{ "mcp4651-104", MCP465x_104 },
262	{ "mcp4652-502", MCP465x_502 },
263	{ "mcp4652-103", MCP465x_103 },
264	{ "mcp4652-503", MCP465x_503 },
265	{ "mcp4652-104", MCP465x_104 },
266	{ "mcp4661-502", MCP466x_502 },
267	{ "mcp4661-103", MCP466x_103 },
268	{ "mcp4661-503", MCP466x_503 },
269	{ "mcp4661-104", MCP466x_104 },
270	{ "mcp4662-502", MCP466x_502 },
271	{ "mcp4662-103", MCP466x_103 },
272	{ "mcp4662-503", MCP466x_503 },
273	{ "mcp4662-104", MCP466x_104 },
274	{}
275};
276MODULE_DEVICE_TABLE(i2c, mcp4531_id);
277
278#define MCP4531_COMPATIBLE(of_compatible, cfg) {	\
279			.compatible = of_compatible,	\
280			.data = &mcp4531_cfg[cfg],	\
281}
282
283static const struct of_device_id mcp4531_of_match[] = {
284	MCP4531_COMPATIBLE("microchip,mcp4531-502", MCP453x_502),
285	MCP4531_COMPATIBLE("microchip,mcp4531-103", MCP453x_103),
286	MCP4531_COMPATIBLE("microchip,mcp4531-503", MCP453x_503),
287	MCP4531_COMPATIBLE("microchip,mcp4531-104", MCP453x_104),
288	MCP4531_COMPATIBLE("microchip,mcp4532-502", MCP453x_502),
289	MCP4531_COMPATIBLE("microchip,mcp4532-103", MCP453x_103),
290	MCP4531_COMPATIBLE("microchip,mcp4532-503", MCP453x_503),
291	MCP4531_COMPATIBLE("microchip,mcp4532-104", MCP453x_104),
292	MCP4531_COMPATIBLE("microchip,mcp4541-502", MCP454x_502),
293	MCP4531_COMPATIBLE("microchip,mcp4541-103", MCP454x_103),
294	MCP4531_COMPATIBLE("microchip,mcp4541-503", MCP454x_503),
295	MCP4531_COMPATIBLE("microchip,mcp4541-104", MCP454x_104),
296	MCP4531_COMPATIBLE("microchip,mcp4542-502", MCP454x_502),
297	MCP4531_COMPATIBLE("microchip,mcp4542-103", MCP454x_103),
298	MCP4531_COMPATIBLE("microchip,mcp4542-503", MCP454x_503),
299	MCP4531_COMPATIBLE("microchip,mcp4542-104", MCP454x_104),
300	MCP4531_COMPATIBLE("microchip,mcp4551-502", MCP455x_502),
301	MCP4531_COMPATIBLE("microchip,mcp4551-103", MCP455x_103),
302	MCP4531_COMPATIBLE("microchip,mcp4551-503", MCP455x_503),
303	MCP4531_COMPATIBLE("microchip,mcp4551-104", MCP455x_104),
304	MCP4531_COMPATIBLE("microchip,mcp4552-502", MCP455x_502),
305	MCP4531_COMPATIBLE("microchip,mcp4552-103", MCP455x_103),
306	MCP4531_COMPATIBLE("microchip,mcp4552-503", MCP455x_503),
307	MCP4531_COMPATIBLE("microchip,mcp4552-104", MCP455x_104),
308	MCP4531_COMPATIBLE("microchip,mcp4561-502", MCP456x_502),
309	MCP4531_COMPATIBLE("microchip,mcp4561-103", MCP456x_103),
310	MCP4531_COMPATIBLE("microchip,mcp4561-503", MCP456x_503),
311	MCP4531_COMPATIBLE("microchip,mcp4561-104", MCP456x_104),
312	MCP4531_COMPATIBLE("microchip,mcp4562-502", MCP456x_502),
313	MCP4531_COMPATIBLE("microchip,mcp4562-103", MCP456x_103),
314	MCP4531_COMPATIBLE("microchip,mcp4562-503", MCP456x_503),
315	MCP4531_COMPATIBLE("microchip,mcp4562-104", MCP456x_104),
316	MCP4531_COMPATIBLE("microchip,mcp4631-502", MCP463x_502),
317	MCP4531_COMPATIBLE("microchip,mcp4631-103", MCP463x_103),
318	MCP4531_COMPATIBLE("microchip,mcp4631-503", MCP463x_503),
319	MCP4531_COMPATIBLE("microchip,mcp4631-104", MCP463x_104),
320	MCP4531_COMPATIBLE("microchip,mcp4632-502", MCP463x_502),
321	MCP4531_COMPATIBLE("microchip,mcp4632-103", MCP463x_103),
322	MCP4531_COMPATIBLE("microchip,mcp4632-503", MCP463x_503),
323	MCP4531_COMPATIBLE("microchip,mcp4632-104", MCP463x_104),
324	MCP4531_COMPATIBLE("microchip,mcp4641-502", MCP464x_502),
325	MCP4531_COMPATIBLE("microchip,mcp4641-103", MCP464x_103),
326	MCP4531_COMPATIBLE("microchip,mcp4641-503", MCP464x_503),
327	MCP4531_COMPATIBLE("microchip,mcp4641-104", MCP464x_104),
328	MCP4531_COMPATIBLE("microchip,mcp4642-502", MCP464x_502),
329	MCP4531_COMPATIBLE("microchip,mcp4642-103", MCP464x_103),
330	MCP4531_COMPATIBLE("microchip,mcp4642-503", MCP464x_503),
331	MCP4531_COMPATIBLE("microchip,mcp4642-104", MCP464x_104),
332	MCP4531_COMPATIBLE("microchip,mcp4651-502", MCP465x_502),
333	MCP4531_COMPATIBLE("microchip,mcp4651-103", MCP465x_103),
334	MCP4531_COMPATIBLE("microchip,mcp4651-503", MCP465x_503),
335	MCP4531_COMPATIBLE("microchip,mcp4651-104", MCP465x_104),
336	MCP4531_COMPATIBLE("microchip,mcp4652-502", MCP465x_502),
337	MCP4531_COMPATIBLE("microchip,mcp4652-103", MCP465x_103),
338	MCP4531_COMPATIBLE("microchip,mcp4652-503", MCP465x_503),
339	MCP4531_COMPATIBLE("microchip,mcp4652-104", MCP465x_104),
340	MCP4531_COMPATIBLE("microchip,mcp4661-502", MCP466x_502),
341	MCP4531_COMPATIBLE("microchip,mcp4661-103", MCP466x_103),
342	MCP4531_COMPATIBLE("microchip,mcp4661-503", MCP466x_503),
343	MCP4531_COMPATIBLE("microchip,mcp4661-104", MCP466x_104),
344	MCP4531_COMPATIBLE("microchip,mcp4662-502", MCP466x_502),
345	MCP4531_COMPATIBLE("microchip,mcp4662-103", MCP466x_103),
346	MCP4531_COMPATIBLE("microchip,mcp4662-503", MCP466x_503),
347	MCP4531_COMPATIBLE("microchip,mcp4662-104", MCP466x_104),
348	{ /* sentinel */ }
349};
350MODULE_DEVICE_TABLE(of, mcp4531_of_match);
351
352static int mcp4531_probe(struct i2c_client *client)
353{
354	struct device *dev = &client->dev;
355	struct mcp4531_data *data;
356	struct iio_dev *indio_dev;
357
358	if (!i2c_check_functionality(client->adapter,
359				     I2C_FUNC_SMBUS_WORD_DATA)) {
360		dev_err(dev, "SMBUS Word Data not supported\n");
361		return -EOPNOTSUPP;
362	}
363
364	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
365	if (!indio_dev)
366		return -ENOMEM;
367	data = iio_priv(indio_dev);
368	i2c_set_clientdata(client, indio_dev);
369	data->client = client;
370
371	data->cfg = device_get_match_data(dev);
372	if (!data->cfg)
373		data->cfg = &mcp4531_cfg[i2c_match_id(mcp4531_id, client)->driver_data];
374
375	indio_dev->info = &mcp4531_info;
376	indio_dev->channels = mcp4531_channels;
377	indio_dev->num_channels = data->cfg->wipers;
378	indio_dev->name = client->name;
379
380	return devm_iio_device_register(dev, indio_dev);
381}
382
383static struct i2c_driver mcp4531_driver = {
384	.driver = {
385		.name	= "mcp4531",
386		.of_match_table = mcp4531_of_match,
387	},
388	.probe_new	= mcp4531_probe,
389	.id_table	= mcp4531_id,
390};
391
392module_i2c_driver(mcp4531_driver);
393
394MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
395MODULE_DESCRIPTION("MCP4531 digital potentiometer");
396MODULE_LICENSE("GPL v2");
397