This source file includes following definitions.
- mcp3422_update_config
- mcp3422_read
- mcp3422_read_channel
- mcp3422_read_raw
- mcp3422_write_raw
- mcp3422_write_raw_get_fmt
- mcp3422_show_samp_freqs
- mcp3422_show_scales
- mcp3422_probe
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16 #include <linux/err.h>
17 #include <linux/i2c.h>
18 #include <linux/module.h>
19 #include <linux/delay.h>
20 #include <linux/sysfs.h>
21 #include <linux/of.h>
22
23 #include <linux/iio/iio.h>
24 #include <linux/iio/sysfs.h>
25
26
27 #define MCP3422_CHANNEL_MASK 0x60
28 #define MCP3422_PGA_MASK 0x03
29 #define MCP3422_SRATE_MASK 0x0C
30 #define MCP3422_SRATE_240 0x0
31 #define MCP3422_SRATE_60 0x1
32 #define MCP3422_SRATE_15 0x2
33 #define MCP3422_SRATE_3 0x3
34 #define MCP3422_PGA_1 0
35 #define MCP3422_PGA_2 1
36 #define MCP3422_PGA_4 2
37 #define MCP3422_PGA_8 3
38 #define MCP3422_CONT_SAMPLING 0x10
39
40 #define MCP3422_CHANNEL(config) (((config) & MCP3422_CHANNEL_MASK) >> 5)
41 #define MCP3422_PGA(config) ((config) & MCP3422_PGA_MASK)
42 #define MCP3422_SAMPLE_RATE(config) (((config) & MCP3422_SRATE_MASK) >> 2)
43
44 #define MCP3422_CHANNEL_VALUE(value) (((value) << 5) & MCP3422_CHANNEL_MASK)
45 #define MCP3422_PGA_VALUE(value) ((value) & MCP3422_PGA_MASK)
46 #define MCP3422_SAMPLE_RATE_VALUE(value) ((value << 2) & MCP3422_SRATE_MASK)
47
48 #define MCP3422_CHAN(_index) \
49 { \
50 .type = IIO_VOLTAGE, \
51 .indexed = 1, \
52 .channel = _index, \
53 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \
54 | BIT(IIO_CHAN_INFO_SCALE), \
55 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
56 }
57
58 static const int mcp3422_scales[4][4] = {
59 { 1000000, 500000, 250000, 125000 },
60 { 250000, 125000, 62500, 31250 },
61 { 62500, 31250, 15625, 7812 },
62 { 15625, 7812, 3906, 1953 } };
63
64
65 static const int mcp3422_read_times[4] = {
66 [MCP3422_SRATE_240] = 1000 / 240,
67 [MCP3422_SRATE_60] = 1000 / 60,
68 [MCP3422_SRATE_15] = 1000 / 15,
69 [MCP3422_SRATE_3] = 1000 / 3 };
70
71
72 static const int mcp3422_sample_rates[4] = {
73 [MCP3422_SRATE_240] = 240,
74 [MCP3422_SRATE_60] = 60,
75 [MCP3422_SRATE_15] = 15,
76 [MCP3422_SRATE_3] = 3 };
77
78
79 static const int mcp3422_sign_extend[4] = {
80 [MCP3422_SRATE_240] = 11,
81 [MCP3422_SRATE_60] = 13,
82 [MCP3422_SRATE_15] = 15,
83 [MCP3422_SRATE_3] = 17 };
84
85
86 struct mcp3422 {
87 struct i2c_client *i2c;
88 u8 id;
89 u8 config;
90 u8 pga[4];
91 struct mutex lock;
92 };
93
94 static int mcp3422_update_config(struct mcp3422 *adc, u8 newconfig)
95 {
96 int ret;
97
98 mutex_lock(&adc->lock);
99
100 ret = i2c_master_send(adc->i2c, &newconfig, 1);
101 if (ret > 0) {
102 adc->config = newconfig;
103 ret = 0;
104 }
105
106 mutex_unlock(&adc->lock);
107
108 return ret;
109 }
110
111 static int mcp3422_read(struct mcp3422 *adc, int *value, u8 *config)
112 {
113 int ret = 0;
114 u8 sample_rate = MCP3422_SAMPLE_RATE(adc->config);
115 u8 buf[4] = {0, 0, 0, 0};
116 u32 temp;
117
118 if (sample_rate == MCP3422_SRATE_3) {
119 ret = i2c_master_recv(adc->i2c, buf, 4);
120 temp = buf[0] << 16 | buf[1] << 8 | buf[2];
121 *config = buf[3];
122 } else {
123 ret = i2c_master_recv(adc->i2c, buf, 3);
124 temp = buf[0] << 8 | buf[1];
125 *config = buf[2];
126 }
127
128 *value = sign_extend32(temp, mcp3422_sign_extend[sample_rate]);
129
130 return ret;
131 }
132
133 static int mcp3422_read_channel(struct mcp3422 *adc,
134 struct iio_chan_spec const *channel, int *value)
135 {
136 int ret;
137 u8 config;
138 u8 req_channel = channel->channel;
139
140 if (req_channel != MCP3422_CHANNEL(adc->config)) {
141 config = adc->config;
142 config &= ~MCP3422_CHANNEL_MASK;
143 config |= MCP3422_CHANNEL_VALUE(req_channel);
144 config &= ~MCP3422_PGA_MASK;
145 config |= MCP3422_PGA_VALUE(adc->pga[req_channel]);
146 ret = mcp3422_update_config(adc, config);
147 if (ret < 0)
148 return ret;
149 msleep(mcp3422_read_times[MCP3422_SAMPLE_RATE(adc->config)]);
150 }
151
152 return mcp3422_read(adc, value, &config);
153 }
154
155 static int mcp3422_read_raw(struct iio_dev *iio,
156 struct iio_chan_spec const *channel, int *val1,
157 int *val2, long mask)
158 {
159 struct mcp3422 *adc = iio_priv(iio);
160 int err;
161
162 u8 sample_rate = MCP3422_SAMPLE_RATE(adc->config);
163 u8 pga = MCP3422_PGA(adc->config);
164
165 switch (mask) {
166 case IIO_CHAN_INFO_RAW:
167 err = mcp3422_read_channel(adc, channel, val1);
168 if (err < 0)
169 return -EINVAL;
170 return IIO_VAL_INT;
171
172 case IIO_CHAN_INFO_SCALE:
173
174 *val1 = 0;
175 *val2 = mcp3422_scales[sample_rate][pga];
176 return IIO_VAL_INT_PLUS_NANO;
177
178 case IIO_CHAN_INFO_SAMP_FREQ:
179 *val1 = mcp3422_sample_rates[MCP3422_SAMPLE_RATE(adc->config)];
180 return IIO_VAL_INT;
181
182 default:
183 break;
184 }
185
186 return -EINVAL;
187 }
188
189 static int mcp3422_write_raw(struct iio_dev *iio,
190 struct iio_chan_spec const *channel, int val1,
191 int val2, long mask)
192 {
193 struct mcp3422 *adc = iio_priv(iio);
194 u8 temp;
195 u8 config = adc->config;
196 u8 req_channel = channel->channel;
197 u8 sample_rate = MCP3422_SAMPLE_RATE(config);
198 u8 i;
199
200 switch (mask) {
201 case IIO_CHAN_INFO_SCALE:
202 if (val1 != 0)
203 return -EINVAL;
204
205 for (i = 0; i < ARRAY_SIZE(mcp3422_scales[0]); i++) {
206 if (val2 == mcp3422_scales[sample_rate][i]) {
207 adc->pga[req_channel] = i;
208
209 config &= ~MCP3422_CHANNEL_MASK;
210 config |= MCP3422_CHANNEL_VALUE(req_channel);
211 config &= ~MCP3422_PGA_MASK;
212 config |= MCP3422_PGA_VALUE(adc->pga[req_channel]);
213
214 return mcp3422_update_config(adc, config);
215 }
216 }
217 return -EINVAL;
218
219 case IIO_CHAN_INFO_SAMP_FREQ:
220 switch (val1) {
221 case 240:
222 temp = MCP3422_SRATE_240;
223 break;
224 case 60:
225 temp = MCP3422_SRATE_60;
226 break;
227 case 15:
228 temp = MCP3422_SRATE_15;
229 break;
230 case 3:
231 if (adc->id > 4)
232 return -EINVAL;
233 temp = MCP3422_SRATE_3;
234 break;
235 default:
236 return -EINVAL;
237 }
238
239 config &= ~MCP3422_CHANNEL_MASK;
240 config |= MCP3422_CHANNEL_VALUE(req_channel);
241 config &= ~MCP3422_SRATE_MASK;
242 config |= MCP3422_SAMPLE_RATE_VALUE(temp);
243
244 return mcp3422_update_config(adc, config);
245
246 default:
247 break;
248 }
249
250 return -EINVAL;
251 }
252
253 static int mcp3422_write_raw_get_fmt(struct iio_dev *indio_dev,
254 struct iio_chan_spec const *chan, long mask)
255 {
256 switch (mask) {
257 case IIO_CHAN_INFO_SCALE:
258 return IIO_VAL_INT_PLUS_NANO;
259 case IIO_CHAN_INFO_SAMP_FREQ:
260 return IIO_VAL_INT_PLUS_MICRO;
261 default:
262 return -EINVAL;
263 }
264 }
265
266 static ssize_t mcp3422_show_samp_freqs(struct device *dev,
267 struct device_attribute *attr, char *buf)
268 {
269 struct mcp3422 *adc = iio_priv(dev_to_iio_dev(dev));
270
271 if (adc->id > 4)
272 return sprintf(buf, "240 60 15\n");
273
274 return sprintf(buf, "240 60 15 3\n");
275 }
276
277 static ssize_t mcp3422_show_scales(struct device *dev,
278 struct device_attribute *attr, char *buf)
279 {
280 struct mcp3422 *adc = iio_priv(dev_to_iio_dev(dev));
281 u8 sample_rate = MCP3422_SAMPLE_RATE(adc->config);
282
283 return sprintf(buf, "0.%09u 0.%09u 0.%09u 0.%09u\n",
284 mcp3422_scales[sample_rate][0],
285 mcp3422_scales[sample_rate][1],
286 mcp3422_scales[sample_rate][2],
287 mcp3422_scales[sample_rate][3]);
288 }
289
290 static IIO_DEVICE_ATTR(sampling_frequency_available, S_IRUGO,
291 mcp3422_show_samp_freqs, NULL, 0);
292 static IIO_DEVICE_ATTR(in_voltage_scale_available, S_IRUGO,
293 mcp3422_show_scales, NULL, 0);
294
295 static struct attribute *mcp3422_attributes[] = {
296 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
297 &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
298 NULL,
299 };
300
301 static const struct attribute_group mcp3422_attribute_group = {
302 .attrs = mcp3422_attributes,
303 };
304
305 static const struct iio_chan_spec mcp3421_channels[] = {
306 MCP3422_CHAN(0),
307 };
308
309 static const struct iio_chan_spec mcp3422_channels[] = {
310 MCP3422_CHAN(0),
311 MCP3422_CHAN(1),
312 };
313
314 static const struct iio_chan_spec mcp3424_channels[] = {
315 MCP3422_CHAN(0),
316 MCP3422_CHAN(1),
317 MCP3422_CHAN(2),
318 MCP3422_CHAN(3),
319 };
320
321 static const struct iio_info mcp3422_info = {
322 .read_raw = mcp3422_read_raw,
323 .write_raw = mcp3422_write_raw,
324 .write_raw_get_fmt = mcp3422_write_raw_get_fmt,
325 .attrs = &mcp3422_attribute_group,
326 };
327
328 static int mcp3422_probe(struct i2c_client *client,
329 const struct i2c_device_id *id)
330 {
331 struct iio_dev *indio_dev;
332 struct mcp3422 *adc;
333 int err;
334 u8 config;
335
336 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
337 return -EOPNOTSUPP;
338
339 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*adc));
340 if (!indio_dev)
341 return -ENOMEM;
342
343 adc = iio_priv(indio_dev);
344 adc->i2c = client;
345 adc->id = (u8)(id->driver_data);
346
347 mutex_init(&adc->lock);
348
349 indio_dev->dev.parent = &client->dev;
350 indio_dev->dev.of_node = client->dev.of_node;
351 indio_dev->name = dev_name(&client->dev);
352 indio_dev->modes = INDIO_DIRECT_MODE;
353 indio_dev->info = &mcp3422_info;
354
355 switch (adc->id) {
356 case 1:
357 case 5:
358 indio_dev->channels = mcp3421_channels;
359 indio_dev->num_channels = ARRAY_SIZE(mcp3421_channels);
360 break;
361 case 2:
362 case 3:
363 case 6:
364 case 7:
365 indio_dev->channels = mcp3422_channels;
366 indio_dev->num_channels = ARRAY_SIZE(mcp3422_channels);
367 break;
368 case 4:
369 case 8:
370 indio_dev->channels = mcp3424_channels;
371 indio_dev->num_channels = ARRAY_SIZE(mcp3424_channels);
372 break;
373 }
374
375
376 config = (MCP3422_CONT_SAMPLING
377 | MCP3422_CHANNEL_VALUE(0)
378 | MCP3422_PGA_VALUE(MCP3422_PGA_1)
379 | MCP3422_SAMPLE_RATE_VALUE(MCP3422_SRATE_240));
380 err = mcp3422_update_config(adc, config);
381 if (err < 0)
382 return err;
383
384 err = devm_iio_device_register(&client->dev, indio_dev);
385 if (err < 0)
386 return err;
387
388 i2c_set_clientdata(client, indio_dev);
389
390 return 0;
391 }
392
393 static const struct i2c_device_id mcp3422_id[] = {
394 { "mcp3421", 1 },
395 { "mcp3422", 2 },
396 { "mcp3423", 3 },
397 { "mcp3424", 4 },
398 { "mcp3425", 5 },
399 { "mcp3426", 6 },
400 { "mcp3427", 7 },
401 { "mcp3428", 8 },
402 { }
403 };
404 MODULE_DEVICE_TABLE(i2c, mcp3422_id);
405
406 #ifdef CONFIG_OF
407 static const struct of_device_id mcp3422_of_match[] = {
408 { .compatible = "mcp3422" },
409 { }
410 };
411 MODULE_DEVICE_TABLE(of, mcp3422_of_match);
412 #endif
413
414 static struct i2c_driver mcp3422_driver = {
415 .driver = {
416 .name = "mcp3422",
417 .of_match_table = of_match_ptr(mcp3422_of_match),
418 },
419 .probe = mcp3422_probe,
420 .id_table = mcp3422_id,
421 };
422 module_i2c_driver(mcp3422_driver);
423
424 MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
425 MODULE_DESCRIPTION("Microchip mcp3421/2/3/4/5/6/7/8 driver");
426 MODULE_LICENSE("GPL v2");