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mm, page_alloc: set alloc_flags only once in slowpath
[linux/fpc-iii.git] / drivers / iio / potentiometer / mcp4531.c
blob13b6ae2fcf7b2cda84553ec95372cfc38020fcfc
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 max_pos;
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, .max_pos = 128, .kohms = 5, },
82 [MCP453x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
83 [MCP453x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, },
84 [MCP453x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
85 [MCP454x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, },
86 [MCP454x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
87 [MCP454x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, },
88 [MCP454x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
89 [MCP455x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, },
90 [MCP455x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, },
91 [MCP455x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
92 [MCP455x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
93 [MCP456x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, },
94 [MCP456x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, },
95 [MCP456x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
96 [MCP456x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
97 [MCP463x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, },
98 [MCP463x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, },
99 [MCP463x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, },
100 [MCP463x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
101 [MCP464x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, },
102 [MCP464x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, },
103 [MCP464x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, },
104 [MCP464x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
105 [MCP465x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, },
106 [MCP465x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, },
107 [MCP465x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, },
108 [MCP465x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
109 [MCP466x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, },
110 [MCP466x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, },
111 [MCP466x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, },
112 [MCP466x_104] = { .wipers = 2, .max_pos = 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 }
135
136 static const struct iio_chan_spec mcp4531_channels[] = {
137 MCP4531_CHANNEL(0),
138 MCP4531_CHANNEL(1),
139 };
140
141 static int mcp4531_read_raw(struct iio_dev *indio_dev,
142 struct iio_chan_spec const *chan,
143 int *val, int *val2, long mask)
144 {
145 struct mcp4531_data *data = iio_priv(indio_dev);
146 int address = chan->channel << MCP4531_WIPER_SHIFT;
147 s32 ret;
148
149 switch (mask) {
150 case IIO_CHAN_INFO_RAW:
151 ret = i2c_smbus_read_word_swapped(data->client,
152 MCP4531_READ | address);
153 if (ret < 0)
154 return ret;
155 *val = ret;
156 return IIO_VAL_INT;
157 case IIO_CHAN_INFO_SCALE:
158 *val = 1000 * data->cfg->kohms;
159 *val2 = data->cfg->max_pos;
160 return IIO_VAL_FRACTIONAL;
161 }
162
163 return -EINVAL;
164 }
165
166 static int mcp4531_write_raw(struct iio_dev *indio_dev,
167 struct iio_chan_spec const *chan,
168 int val, int val2, long mask)
169 {
170 struct mcp4531_data *data = iio_priv(indio_dev);
171 int address = chan->channel << MCP4531_WIPER_SHIFT;
172
173 switch (mask) {
174 case IIO_CHAN_INFO_RAW:
175 if (val > data->cfg->max_pos || val < 0)
176 return -EINVAL;
177 break;
178 default:
179 return -EINVAL;
180 }
181
182 return i2c_smbus_write_byte_data(data->client,
183 MCP4531_WRITE | address | (val >> 8),
184 val & 0xff);
185 }
186
187 static const struct iio_info mcp4531_info = {
188 .read_raw = mcp4531_read_raw,
189 .write_raw = mcp4531_write_raw,
190 .driver_module = THIS_MODULE,
191 };
192
193 #ifdef CONFIG_OF
194
195 #define MCP4531_COMPATIBLE(of_compatible, cfg) { \
196 .compatible = of_compatible, \
197 .data = &mcp4531_cfg[cfg], \
198 }
199
200 static const struct of_device_id mcp4531_of_match[] = {
201 MCP4531_COMPATIBLE("microchip,mcp4531-502", MCP453x_502),
202 MCP4531_COMPATIBLE("microchip,mcp4531-103", MCP453x_103),
203 MCP4531_COMPATIBLE("microchip,mcp4531-503", MCP453x_503),
204 MCP4531_COMPATIBLE("microchip,mcp4531-104", MCP453x_104),
205 MCP4531_COMPATIBLE("microchip,mcp4532-502", MCP453x_502),
206 MCP4531_COMPATIBLE("microchip,mcp4532-103", MCP453x_103),
207 MCP4531_COMPATIBLE("microchip,mcp4532-503", MCP453x_503),
208 MCP4531_COMPATIBLE("microchip,mcp4532-104", MCP453x_104),
209 MCP4531_COMPATIBLE("microchip,mcp4541-502", MCP454x_502),
210 MCP4531_COMPATIBLE("microchip,mcp4541-103", MCP454x_103),
211 MCP4531_COMPATIBLE("microchip,mcp4541-503", MCP454x_503),
212 MCP4531_COMPATIBLE("microchip,mcp4541-104", MCP454x_104),
213 MCP4531_COMPATIBLE("microchip,mcp4542-502", MCP454x_502),
214 MCP4531_COMPATIBLE("microchip,mcp4542-103", MCP454x_103),
215 MCP4531_COMPATIBLE("microchip,mcp4542-503", MCP454x_503),
216 MCP4531_COMPATIBLE("microchip,mcp4542-104", MCP454x_104),
217 MCP4531_COMPATIBLE("microchip,mcp4551-502", MCP455x_502),
218 MCP4531_COMPATIBLE("microchip,mcp4551-103", MCP455x_103),
219 MCP4531_COMPATIBLE("microchip,mcp4551-503", MCP455x_503),
220 MCP4531_COMPATIBLE("microchip,mcp4551-104", MCP455x_104),
221 MCP4531_COMPATIBLE("microchip,mcp4552-502", MCP455x_502),
222 MCP4531_COMPATIBLE("microchip,mcp4552-103", MCP455x_103),
223 MCP4531_COMPATIBLE("microchip,mcp4552-503", MCP455x_503),
224 MCP4531_COMPATIBLE("microchip,mcp4552-104", MCP455x_104),
225 MCP4531_COMPATIBLE("microchip,mcp4561-502", MCP456x_502),
226 MCP4531_COMPATIBLE("microchip,mcp4561-103", MCP456x_103),
227 MCP4531_COMPATIBLE("microchip,mcp4561-503", MCP456x_503),
228 MCP4531_COMPATIBLE("microchip,mcp4561-104", MCP456x_104),
229 MCP4531_COMPATIBLE("microchip,mcp4562-502", MCP456x_502),
230 MCP4531_COMPATIBLE("microchip,mcp4562-103", MCP456x_103),
231 MCP4531_COMPATIBLE("microchip,mcp4562-503", MCP456x_503),
232 MCP4531_COMPATIBLE("microchip,mcp4562-104", MCP456x_104),
233 MCP4531_COMPATIBLE("microchip,mcp4631-502", MCP463x_502),
234 MCP4531_COMPATIBLE("microchip,mcp4631-103", MCP463x_103),
235 MCP4531_COMPATIBLE("microchip,mcp4631-503", MCP463x_503),
236 MCP4531_COMPATIBLE("microchip,mcp4631-104", MCP463x_104),
237 MCP4531_COMPATIBLE("microchip,mcp4632-502", MCP463x_502),
238 MCP4531_COMPATIBLE("microchip,mcp4632-103", MCP463x_103),
239 MCP4531_COMPATIBLE("microchip,mcp4632-503", MCP463x_503),
240 MCP4531_COMPATIBLE("microchip,mcp4632-104", MCP463x_104),
241 MCP4531_COMPATIBLE("microchip,mcp4641-502", MCP464x_502),
242 MCP4531_COMPATIBLE("microchip,mcp4641-103", MCP464x_103),
243 MCP4531_COMPATIBLE("microchip,mcp4641-503", MCP464x_503),
244 MCP4531_COMPATIBLE("microchip,mcp4641-104", MCP464x_104),
245 MCP4531_COMPATIBLE("microchip,mcp4642-502", MCP464x_502),
246 MCP4531_COMPATIBLE("microchip,mcp4642-103", MCP464x_103),
247 MCP4531_COMPATIBLE("microchip,mcp4642-503", MCP464x_503),
248 MCP4531_COMPATIBLE("microchip,mcp4642-104", MCP464x_104),
249 MCP4531_COMPATIBLE("microchip,mcp4651-502", MCP465x_502),
250 MCP4531_COMPATIBLE("microchip,mcp4651-103", MCP465x_103),
251 MCP4531_COMPATIBLE("microchip,mcp4651-503", MCP465x_503),
252 MCP4531_COMPATIBLE("microchip,mcp4651-104", MCP465x_104),
253 MCP4531_COMPATIBLE("microchip,mcp4652-502", MCP465x_502),
254 MCP4531_COMPATIBLE("microchip,mcp4652-103", MCP465x_103),
255 MCP4531_COMPATIBLE("microchip,mcp4652-503", MCP465x_503),
256 MCP4531_COMPATIBLE("microchip,mcp4652-104", MCP465x_104),
257 MCP4531_COMPATIBLE("microchip,mcp4661-502", MCP466x_502),
258 MCP4531_COMPATIBLE("microchip,mcp4661-103", MCP466x_103),
259 MCP4531_COMPATIBLE("microchip,mcp4661-503", MCP466x_503),
260 MCP4531_COMPATIBLE("microchip,mcp4661-104", MCP466x_104),
261 MCP4531_COMPATIBLE("microchip,mcp4662-502", MCP466x_502),
262 MCP4531_COMPATIBLE("microchip,mcp4662-103", MCP466x_103),
263 MCP4531_COMPATIBLE("microchip,mcp4662-503", MCP466x_503),
264 MCP4531_COMPATIBLE("microchip,mcp4662-104", MCP466x_104),
265 { /* sentinel */ }
266 };
267 #endif
268
269 static int mcp4531_probe(struct i2c_client *client,
270 const struct i2c_device_id *id)
271 {
272 struct device *dev = &client->dev;
273 struct mcp4531_data *data;
274 struct iio_dev *indio_dev;
275 const struct of_device_id *match;
276
277 if (!i2c_check_functionality(client->adapter,
278 I2C_FUNC_SMBUS_WORD_DATA)) {
279 dev_err(dev, "SMBUS Word Data not supported\n");
280 return -EOPNOTSUPP;
281 }
282
283 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
284 if (!indio_dev)
285 return -ENOMEM;
286 data = iio_priv(indio_dev);
287 i2c_set_clientdata(client, indio_dev);
288 data->client = client;
289
290 match = of_match_device(of_match_ptr(mcp4531_of_match), dev);
291 if (match)
292 data->cfg = of_device_get_match_data(dev);
293 else
294 data->cfg = &mcp4531_cfg[id->driver_data];
295
296 indio_dev->dev.parent = dev;
297 indio_dev->info = &mcp4531_info;
298 indio_dev->channels = mcp4531_channels;
299 indio_dev->num_channels = data->cfg->wipers;
300 indio_dev->name = client->name;
301
302 return devm_iio_device_register(dev, indio_dev);
303 }
304
305 static const struct i2c_device_id mcp4531_id[] = {
306 { "mcp4531-502", MCP453x_502 },
307 { "mcp4531-103", MCP453x_103 },
308 { "mcp4531-503", MCP453x_503 },
309 { "mcp4531-104", MCP453x_104 },
310 { "mcp4532-502", MCP453x_502 },
311 { "mcp4532-103", MCP453x_103 },
312 { "mcp4532-503", MCP453x_503 },
313 { "mcp4532-104", MCP453x_104 },
314 { "mcp4541-502", MCP454x_502 },
315 { "mcp4541-103", MCP454x_103 },
316 { "mcp4541-503", MCP454x_503 },
317 { "mcp4541-104", MCP454x_104 },
318 { "mcp4542-502", MCP454x_502 },
319 { "mcp4542-103", MCP454x_103 },
320 { "mcp4542-503", MCP454x_503 },
321 { "mcp4542-104", MCP454x_104 },
322 { "mcp4551-502", MCP455x_502 },
323 { "mcp4551-103", MCP455x_103 },
324 { "mcp4551-503", MCP455x_503 },
325 { "mcp4551-104", MCP455x_104 },
326 { "mcp4552-502", MCP455x_502 },
327 { "mcp4552-103", MCP455x_103 },
328 { "mcp4552-503", MCP455x_503 },
329 { "mcp4552-104", MCP455x_104 },
330 { "mcp4561-502", MCP456x_502 },
331 { "mcp4561-103", MCP456x_103 },
332 { "mcp4561-503", MCP456x_503 },
333 { "mcp4561-104", MCP456x_104 },
334 { "mcp4562-502", MCP456x_502 },
335 { "mcp4562-103", MCP456x_103 },
336 { "mcp4562-503", MCP456x_503 },
337 { "mcp4562-104", MCP456x_104 },
338 { "mcp4631-502", MCP463x_502 },
339 { "mcp4631-103", MCP463x_103 },
340 { "mcp4631-503", MCP463x_503 },
341 { "mcp4631-104", MCP463x_104 },
342 { "mcp4632-502", MCP463x_502 },
343 { "mcp4632-103", MCP463x_103 },
344 { "mcp4632-503", MCP463x_503 },
345 { "mcp4632-104", MCP463x_104 },
346 { "mcp4641-502", MCP464x_502 },
347 { "mcp4641-103", MCP464x_103 },
348 { "mcp4641-503", MCP464x_503 },
349 { "mcp4641-104", MCP464x_104 },
350 { "mcp4642-502", MCP464x_502 },
351 { "mcp4642-103", MCP464x_103 },
352 { "mcp4642-503", MCP464x_503 },
353 { "mcp4642-104", MCP464x_104 },
354 { "mcp4651-502", MCP465x_502 },
355 { "mcp4651-103", MCP465x_103 },
356 { "mcp4651-503", MCP465x_503 },
357 { "mcp4651-104", MCP465x_104 },
358 { "mcp4652-502", MCP465x_502 },
359 { "mcp4652-103", MCP465x_103 },
360 { "mcp4652-503", MCP465x_503 },
361 { "mcp4652-104", MCP465x_104 },
362 { "mcp4661-502", MCP466x_502 },
363 { "mcp4661-103", MCP466x_103 },
364 { "mcp4661-503", MCP466x_503 },
365 { "mcp4661-104", MCP466x_104 },
366 { "mcp4662-502", MCP466x_502 },
367 { "mcp4662-103", MCP466x_103 },
368 { "mcp4662-503", MCP466x_503 },
369 { "mcp4662-104", MCP466x_104 },
370 {}
371 };
372 MODULE_DEVICE_TABLE(i2c, mcp4531_id);
373
374 static struct i2c_driver mcp4531_driver = {
375 .driver = {
376 .name = "mcp4531",
377 .of_match_table = of_match_ptr(mcp4531_of_match),
378 },
379 .probe = mcp4531_probe,
380 .id_table = mcp4531_id,
381 };
382
383 module_i2c_driver(mcp4531_driver);
384
385 MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
386 MODULE_DESCRIPTION("MCP4531 digital potentiometer");
387 MODULE_LICENSE("GPL");
Linux with added FPC-III support