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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/mod_devicetable.h>
20#include <linux/property.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
33struct 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
45static 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
58static 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}
71static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
72
73static 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
124static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
125
126static struct attribute *mcp4725_attributes[] = {
127 &iio_dev_attr_store_eeprom.dev_attr.attr,
128 NULL,
129};
130
131static const struct attribute_group mcp4725_attribute_group = {
132 .attrs = mcp4725_attributes,
133};
134
135static const char * const mcp4725_powerdown_modes[] = {
136 "1kohm_to_gnd",
137 "100kohm_to_gnd",
138 "500kohm_to_gnd"
139};
140
141static const char * const mcp4726_powerdown_modes[] = {
142 "1kohm_to_gnd",
143 "125kohm_to_gnd",
144 "640kohm_to_gnd"
145};
146
147static 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
155static 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
165static 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 sysfs_emit(buf, "%d\n", data->powerdown);
171}
172
173static 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
195enum chip_id {
196 MCP4725,
197 MCP4726,
198};
199
200static 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
215static 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
229static 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
243static 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
264static 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
285static 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
307static 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
334static 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
354static 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
360static int mcp4725_probe_dt(struct device *dev,
361 struct mcp4725_platform_data *pdata)
362{
363
364 pdata->use_vref = device_property_read_bool(dev, "vref-supply");
365 pdata->vref_buffered =
366 device_property_read_bool(dev, "microchip,vref-buffered");
367
368 return 0;
369}
370
371static int mcp4725_probe(struct i2c_client *client,
372 const struct i2c_device_id *id)
373{
374 struct mcp4725_data *data;
375 struct iio_dev *indio_dev;
376 struct mcp4725_platform_data *pdata, pdata_dt;
377 u8 inbuf[4];
378 u8 pd;
379 u8 ref;
380 int err;
381
382 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
383 if (indio_dev == NULL)
384 return -ENOMEM;
385 data = iio_priv(indio_dev);
386 i2c_set_clientdata(client, indio_dev);
387 data->client = client;
388 if (dev_fwnode(&client->dev))
389 data->id = (enum chip_id)device_get_match_data(&client->dev);
390 else
391 data->id = id->driver_data;
392 pdata = dev_get_platdata(&client->dev);
393
394 if (!pdata) {
395 err = mcp4725_probe_dt(&client->dev, &pdata_dt);
396 if (err) {
397 dev_err(&client->dev,
398 "invalid platform or devicetree data");
399 return err;
400 }
401 pdata = &pdata_dt;
402 }
403
404 if (data->id == MCP4725 && pdata->use_vref) {
405 dev_err(&client->dev,
406 "external reference is unavailable on MCP4725");
407 return -EINVAL;
408 }
409
410 if (!pdata->use_vref && pdata->vref_buffered) {
411 dev_err(&client->dev,
412 "buffering is unavailable on the internal reference");
413 return -EINVAL;
414 }
415
416 if (!pdata->use_vref)
417 data->ref_mode = MCP472X_REF_VDD;
418 else
419 data->ref_mode = pdata->vref_buffered ?
420 MCP472X_REF_VREF_BUFFERED :
421 MCP472X_REF_VREF_UNBUFFERED;
422
423 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
424 if (IS_ERR(data->vdd_reg))
425 return PTR_ERR(data->vdd_reg);
426
427 err = regulator_enable(data->vdd_reg);
428 if (err)
429 return err;
430
431 if (pdata->use_vref) {
432 data->vref_reg = devm_regulator_get(&client->dev, "vref");
433 if (IS_ERR(data->vref_reg)) {
434 err = PTR_ERR(data->vref_reg);
435 goto err_disable_vdd_reg;
436 }
437
438 err = regulator_enable(data->vref_reg);
439 if (err)
440 goto err_disable_vdd_reg;
441 }
442
443 indio_dev->name = id->name;
444 indio_dev->info = &mcp4725_info;
445 indio_dev->channels = &mcp472x_channel[id->driver_data];
446 indio_dev->num_channels = 1;
447 indio_dev->modes = INDIO_DIRECT_MODE;
448
449
450 err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
451
452 if (err < 0) {
453 dev_err(&client->dev, "failed to read DAC value");
454 goto err_disable_vref_reg;
455 }
456 pd = (inbuf[0] >> 1) & 0x3;
457 data->powerdown = pd > 0;
458 data->powerdown_mode = pd ? pd - 1 : 2;
459 data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
460 if (data->id == MCP4726)
461 ref = (inbuf[3] >> 3) & 0x3;
462
463 if (data->id == MCP4726 && ref != data->ref_mode) {
464 dev_info(&client->dev,
465 "voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
466 data->ref_mode, ref, data->ref_mode);
467 err = mcp4726_set_cfg(indio_dev);
468 if (err < 0)
469 goto err_disable_vref_reg;
470 }
471
472 err = iio_device_register(indio_dev);
473 if (err)
474 goto err_disable_vref_reg;
475
476 return 0;
477
478err_disable_vref_reg:
479 if (data->vref_reg)
480 regulator_disable(data->vref_reg);
481
482err_disable_vdd_reg:
483 regulator_disable(data->vdd_reg);
484
485 return err;
486}
487
488static int mcp4725_remove(struct i2c_client *client)
489{
490 struct iio_dev *indio_dev = i2c_get_clientdata(client);
491 struct mcp4725_data *data = iio_priv(indio_dev);
492
493 iio_device_unregister(indio_dev);
494
495 if (data->vref_reg)
496 regulator_disable(data->vref_reg);
497 regulator_disable(data->vdd_reg);
498
499 return 0;
500}
501
502static const struct i2c_device_id mcp4725_id[] = {
503 { "mcp4725", MCP4725 },
504 { "mcp4726", MCP4726 },
505 { }
506};
507MODULE_DEVICE_TABLE(i2c, mcp4725_id);
508
509static const struct of_device_id mcp4725_of_match[] = {
510 {
511 .compatible = "microchip,mcp4725",
512 .data = (void *)MCP4725
513 },
514 {
515 .compatible = "microchip,mcp4726",
516 .data = (void *)MCP4726
517 },
518 { }
519};
520MODULE_DEVICE_TABLE(of, mcp4725_of_match);
521
522static struct i2c_driver mcp4725_driver = {
523 .driver = {
524 .name = MCP4725_DRV_NAME,
525 .of_match_table = mcp4725_of_match,
526 .pm = &mcp4725_pm_ops,
527 },
528 .probe = mcp4725_probe,
529 .remove = mcp4725_remove,
530 .id_table = mcp4725_id,
531};
532module_i2c_driver(mcp4725_driver);
533
534MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
535MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");
536MODULE_LICENSE("GPL");
537
