This source file includes following definitions.
- mcp4725_suspend
- mcp4725_resume
- mcp4725_store_eeprom
- mcp4725_get_powerdown_mode
- mcp4725_set_powerdown_mode
- mcp4725_read_powerdown
- mcp4725_write_powerdown
- mcp4725_set_value
- mcp4726_set_cfg
- mcp4725_read_raw
- mcp4725_write_raw
- mcp4725_probe_dt
- mcp4725_probe_dt
- mcp4725_probe
- mcp4725_remove
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14 #include <linux/module.h>
15 #include <linux/i2c.h>
16 #include <linux/err.h>
17 #include <linux/delay.h>
18 #include <linux/regulator/consumer.h>
19 #include <linux/of_device.h>
20 #include <linux/of.h>
21
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24
25 #include <linux/iio/dac/mcp4725.h>
26
27 #define MCP4725_DRV_NAME "mcp4725"
28
29 #define MCP472X_REF_VDD 0x00
30 #define MCP472X_REF_VREF_UNBUFFERED 0x02
31 #define MCP472X_REF_VREF_BUFFERED 0x03
32
33 struct mcp4725_data {
34 struct i2c_client *client;
35 int id;
36 unsigned ref_mode;
37 bool vref_buffered;
38 u16 dac_value;
39 bool powerdown;
40 unsigned powerdown_mode;
41 struct regulator *vdd_reg;
42 struct regulator *vref_reg;
43 };
44
45 static int __maybe_unused mcp4725_suspend(struct device *dev)
46 {
47 struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
48 to_i2c_client(dev)));
49 u8 outbuf[2];
50
51 outbuf[0] = (data->powerdown_mode + 1) << 4;
52 outbuf[1] = 0;
53 data->powerdown = true;
54
55 return i2c_master_send(data->client, outbuf, 2);
56 }
57
58 static int __maybe_unused mcp4725_resume(struct device *dev)
59 {
60 struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
61 to_i2c_client(dev)));
62 u8 outbuf[2];
63
64
65 outbuf[0] = (data->dac_value >> 8) & 0xf;
66 outbuf[1] = data->dac_value & 0xff;
67 data->powerdown = false;
68
69 return i2c_master_send(data->client, outbuf, 2);
70 }
71 static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
72
73 static ssize_t mcp4725_store_eeprom(struct device *dev,
74 struct device_attribute *attr, const char *buf, size_t len)
75 {
76 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
77 struct mcp4725_data *data = iio_priv(indio_dev);
78 int tries = 20;
79 u8 inoutbuf[3];
80 bool state;
81 int ret;
82
83 ret = strtobool(buf, &state);
84 if (ret < 0)
85 return ret;
86
87 if (!state)
88 return 0;
89
90 inoutbuf[0] = 0x60;
91 inoutbuf[0] |= data->ref_mode << 3;
92 inoutbuf[0] |= data->powerdown ? ((data->powerdown_mode + 1) << 1) : 0;
93 inoutbuf[1] = data->dac_value >> 4;
94 inoutbuf[2] = (data->dac_value & 0xf) << 4;
95
96 ret = i2c_master_send(data->client, inoutbuf, 3);
97 if (ret < 0)
98 return ret;
99 else if (ret != 3)
100 return -EIO;
101
102
103 while (tries--) {
104 msleep(20);
105 ret = i2c_master_recv(data->client, inoutbuf, 3);
106 if (ret < 0)
107 return ret;
108 else if (ret != 3)
109 return -EIO;
110
111 if (inoutbuf[0] & 0x80)
112 break;
113 }
114
115 if (tries < 0) {
116 dev_err(&data->client->dev,
117 "mcp4725_store_eeprom() failed, incomplete\n");
118 return -EIO;
119 }
120
121 return len;
122 }
123
124 static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
125
126 static struct attribute *mcp4725_attributes[] = {
127 &iio_dev_attr_store_eeprom.dev_attr.attr,
128 NULL,
129 };
130
131 static const struct attribute_group mcp4725_attribute_group = {
132 .attrs = mcp4725_attributes,
133 };
134
135 static const char * const mcp4725_powerdown_modes[] = {
136 "1kohm_to_gnd",
137 "100kohm_to_gnd",
138 "500kohm_to_gnd"
139 };
140
141 static const char * const mcp4726_powerdown_modes[] = {
142 "1kohm_to_gnd",
143 "125kohm_to_gnd",
144 "640kohm_to_gnd"
145 };
146
147 static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
148 const struct iio_chan_spec *chan)
149 {
150 struct mcp4725_data *data = iio_priv(indio_dev);
151
152 return data->powerdown_mode;
153 }
154
155 static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
156 const struct iio_chan_spec *chan, unsigned mode)
157 {
158 struct mcp4725_data *data = iio_priv(indio_dev);
159
160 data->powerdown_mode = mode;
161
162 return 0;
163 }
164
165 static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
166 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
167 {
168 struct mcp4725_data *data = iio_priv(indio_dev);
169
170 return sprintf(buf, "%d\n", data->powerdown);
171 }
172
173 static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev,
174 uintptr_t private, const struct iio_chan_spec *chan,
175 const char *buf, size_t len)
176 {
177 struct mcp4725_data *data = iio_priv(indio_dev);
178 bool state;
179 int ret;
180
181 ret = strtobool(buf, &state);
182 if (ret)
183 return ret;
184
185 if (state)
186 ret = mcp4725_suspend(&data->client->dev);
187 else
188 ret = mcp4725_resume(&data->client->dev);
189 if (ret < 0)
190 return ret;
191
192 return len;
193 }
194
195 enum chip_id {
196 MCP4725,
197 MCP4726,
198 };
199
200 static const struct iio_enum mcp472x_powerdown_mode_enum[] = {
201 [MCP4725] = {
202 .items = mcp4725_powerdown_modes,
203 .num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
204 .get = mcp4725_get_powerdown_mode,
205 .set = mcp4725_set_powerdown_mode,
206 },
207 [MCP4726] = {
208 .items = mcp4726_powerdown_modes,
209 .num_items = ARRAY_SIZE(mcp4726_powerdown_modes),
210 .get = mcp4725_get_powerdown_mode,
211 .set = mcp4725_set_powerdown_mode,
212 },
213 };
214
215 static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
216 {
217 .name = "powerdown",
218 .read = mcp4725_read_powerdown,
219 .write = mcp4725_write_powerdown,
220 .shared = IIO_SEPARATE,
221 },
222 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
223 &mcp472x_powerdown_mode_enum[MCP4725]),
224 IIO_ENUM_AVAILABLE("powerdown_mode",
225 &mcp472x_powerdown_mode_enum[MCP4725]),
226 { },
227 };
228
229 static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = {
230 {
231 .name = "powerdown",
232 .read = mcp4725_read_powerdown,
233 .write = mcp4725_write_powerdown,
234 .shared = IIO_SEPARATE,
235 },
236 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
237 &mcp472x_powerdown_mode_enum[MCP4726]),
238 IIO_ENUM_AVAILABLE("powerdown_mode",
239 &mcp472x_powerdown_mode_enum[MCP4726]),
240 { },
241 };
242
243 static const struct iio_chan_spec mcp472x_channel[] = {
244 [MCP4725] = {
245 .type = IIO_VOLTAGE,
246 .indexed = 1,
247 .output = 1,
248 .channel = 0,
249 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
250 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
251 .ext_info = mcp4725_ext_info,
252 },
253 [MCP4726] = {
254 .type = IIO_VOLTAGE,
255 .indexed = 1,
256 .output = 1,
257 .channel = 0,
258 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
259 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
260 .ext_info = mcp4726_ext_info,
261 },
262 };
263
264 static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
265 {
266 struct mcp4725_data *data = iio_priv(indio_dev);
267 u8 outbuf[2];
268 int ret;
269
270 if (val >= (1 << 12) || val < 0)
271 return -EINVAL;
272
273 outbuf[0] = (val >> 8) & 0xf;
274 outbuf[1] = val & 0xff;
275
276 ret = i2c_master_send(data->client, outbuf, 2);
277 if (ret < 0)
278 return ret;
279 else if (ret != 2)
280 return -EIO;
281 else
282 return 0;
283 }
284
285 static int mcp4726_set_cfg(struct iio_dev *indio_dev)
286 {
287 struct mcp4725_data *data = iio_priv(indio_dev);
288 u8 outbuf[3];
289 int ret;
290
291 outbuf[0] = 0x40;
292 outbuf[0] |= data->ref_mode << 3;
293 if (data->powerdown)
294 outbuf[0] |= data->powerdown << 1;
295 outbuf[1] = data->dac_value >> 4;
296 outbuf[2] = (data->dac_value & 0xf) << 4;
297
298 ret = i2c_master_send(data->client, outbuf, 3);
299 if (ret < 0)
300 return ret;
301 else if (ret != 3)
302 return -EIO;
303 else
304 return 0;
305 }
306
307 static int mcp4725_read_raw(struct iio_dev *indio_dev,
308 struct iio_chan_spec const *chan,
309 int *val, int *val2, long mask)
310 {
311 struct mcp4725_data *data = iio_priv(indio_dev);
312 int ret;
313
314 switch (mask) {
315 case IIO_CHAN_INFO_RAW:
316 *val = data->dac_value;
317 return IIO_VAL_INT;
318 case IIO_CHAN_INFO_SCALE:
319 if (data->ref_mode == MCP472X_REF_VDD)
320 ret = regulator_get_voltage(data->vdd_reg);
321 else
322 ret = regulator_get_voltage(data->vref_reg);
323
324 if (ret < 0)
325 return ret;
326
327 *val = ret / 1000;
328 *val2 = 12;
329 return IIO_VAL_FRACTIONAL_LOG2;
330 }
331 return -EINVAL;
332 }
333
334 static int mcp4725_write_raw(struct iio_dev *indio_dev,
335 struct iio_chan_spec const *chan,
336 int val, int val2, long mask)
337 {
338 struct mcp4725_data *data = iio_priv(indio_dev);
339 int ret;
340
341 switch (mask) {
342 case IIO_CHAN_INFO_RAW:
343 ret = mcp4725_set_value(indio_dev, val);
344 data->dac_value = val;
345 break;
346 default:
347 ret = -EINVAL;
348 break;
349 }
350
351 return ret;
352 }
353
354 static const struct iio_info mcp4725_info = {
355 .read_raw = mcp4725_read_raw,
356 .write_raw = mcp4725_write_raw,
357 .attrs = &mcp4725_attribute_group,
358 };
359
360 #ifdef CONFIG_OF
361 static int mcp4725_probe_dt(struct device *dev,
362 struct mcp4725_platform_data *pdata)
363 {
364 struct device_node *np = dev->of_node;
365
366 if (!np)
367 return -ENODEV;
368
369
370 pdata->use_vref = of_property_read_bool(np, "vref-supply");
371 pdata->vref_buffered =
372 of_property_read_bool(np, "microchip,vref-buffered");
373
374 return 0;
375 }
376 #else
377 static int mcp4725_probe_dt(struct device *dev,
378 struct mcp4725_platform_data *platform_data)
379 {
380 return -ENODEV;
381 }
382 #endif
383
384 static int mcp4725_probe(struct i2c_client *client,
385 const struct i2c_device_id *id)
386 {
387 struct mcp4725_data *data;
388 struct iio_dev *indio_dev;
389 struct mcp4725_platform_data *pdata, pdata_dt;
390 u8 inbuf[4];
391 u8 pd;
392 u8 ref;
393 int err;
394
395 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
396 if (indio_dev == NULL)
397 return -ENOMEM;
398 data = iio_priv(indio_dev);
399 i2c_set_clientdata(client, indio_dev);
400 data->client = client;
401 if (client->dev.of_node)
402 data->id = (enum chip_id)of_device_get_match_data(&client->dev);
403 else
404 data->id = id->driver_data;
405 pdata = dev_get_platdata(&client->dev);
406
407 if (!pdata) {
408 err = mcp4725_probe_dt(&client->dev, &pdata_dt);
409 if (err) {
410 dev_err(&client->dev,
411 "invalid platform or devicetree data");
412 return err;
413 }
414 pdata = &pdata_dt;
415 }
416
417 if (data->id == MCP4725 && pdata->use_vref) {
418 dev_err(&client->dev,
419 "external reference is unavailable on MCP4725");
420 return -EINVAL;
421 }
422
423 if (!pdata->use_vref && pdata->vref_buffered) {
424 dev_err(&client->dev,
425 "buffering is unavailable on the internal reference");
426 return -EINVAL;
427 }
428
429 if (!pdata->use_vref)
430 data->ref_mode = MCP472X_REF_VDD;
431 else
432 data->ref_mode = pdata->vref_buffered ?
433 MCP472X_REF_VREF_BUFFERED :
434 MCP472X_REF_VREF_UNBUFFERED;
435
436 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
437 if (IS_ERR(data->vdd_reg))
438 return PTR_ERR(data->vdd_reg);
439
440 err = regulator_enable(data->vdd_reg);
441 if (err)
442 return err;
443
444 if (pdata->use_vref) {
445 data->vref_reg = devm_regulator_get(&client->dev, "vref");
446 if (IS_ERR(data->vref_reg)) {
447 err = PTR_ERR(data->vref_reg);
448 goto err_disable_vdd_reg;
449 }
450
451 err = regulator_enable(data->vref_reg);
452 if (err)
453 goto err_disable_vdd_reg;
454 }
455
456 indio_dev->dev.parent = &client->dev;
457 indio_dev->name = id->name;
458 indio_dev->info = &mcp4725_info;
459 indio_dev->channels = &mcp472x_channel[id->driver_data];
460 indio_dev->num_channels = 1;
461 indio_dev->modes = INDIO_DIRECT_MODE;
462
463
464 err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
465
466 if (err < 0) {
467 dev_err(&client->dev, "failed to read DAC value");
468 goto err_disable_vref_reg;
469 }
470 pd = (inbuf[0] >> 1) & 0x3;
471 data->powerdown = pd > 0;
472 data->powerdown_mode = pd ? pd - 1 : 2;
473 data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
474 if (data->id == MCP4726)
475 ref = (inbuf[3] >> 3) & 0x3;
476
477 if (data->id == MCP4726 && ref != data->ref_mode) {
478 dev_info(&client->dev,
479 "voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
480 data->ref_mode, ref, data->ref_mode);
481 err = mcp4726_set_cfg(indio_dev);
482 if (err < 0)
483 goto err_disable_vref_reg;
484 }
485
486 err = iio_device_register(indio_dev);
487 if (err)
488 goto err_disable_vref_reg;
489
490 return 0;
491
492 err_disable_vref_reg:
493 if (data->vref_reg)
494 regulator_disable(data->vref_reg);
495
496 err_disable_vdd_reg:
497 regulator_disable(data->vdd_reg);
498
499 return err;
500 }
501
502 static int mcp4725_remove(struct i2c_client *client)
503 {
504 struct iio_dev *indio_dev = i2c_get_clientdata(client);
505 struct mcp4725_data *data = iio_priv(indio_dev);
506
507 iio_device_unregister(indio_dev);
508
509 if (data->vref_reg)
510 regulator_disable(data->vref_reg);
511 regulator_disable(data->vdd_reg);
512
513 return 0;
514 }
515
516 static const struct i2c_device_id mcp4725_id[] = {
517 { "mcp4725", MCP4725 },
518 { "mcp4726", MCP4726 },
519 { }
520 };
521 MODULE_DEVICE_TABLE(i2c, mcp4725_id);
522
523 #ifdef CONFIG_OF
524 static const struct of_device_id mcp4725_of_match[] = {
525 {
526 .compatible = "microchip,mcp4725",
527 .data = (void *)MCP4725
528 },
529 {
530 .compatible = "microchip,mcp4726",
531 .data = (void *)MCP4726
532 },
533 { }
534 };
535 MODULE_DEVICE_TABLE(of, mcp4725_of_match);
536 #endif
537
538 static struct i2c_driver mcp4725_driver = {
539 .driver = {
540 .name = MCP4725_DRV_NAME,
541 .of_match_table = of_match_ptr(mcp4725_of_match),
542 .pm = &mcp4725_pm_ops,
543 },
544 .probe = mcp4725_probe,
545 .remove = mcp4725_remove,
546 .id_table = mcp4725_id,
547 };
548 module_i2c_driver(mcp4725_driver);
549
550 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
551 MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");
552 MODULE_LICENSE("GPL");