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17#include <linux/module.h>
18#include <linux/i2c.h>
19#include <linux/err.h>
20#include <linux/delay.h>
21#include <linux/regulator/consumer.h>
22#include <linux/of_device.h>
23#include <linux/of.h>
24
25#include <linux/iio/iio.h>
26#include <linux/iio/sysfs.h>
27
28#include <linux/iio/dac/mcp4725.h>
29
30#define MCP4725_DRV_NAME "mcp4725"
31
32#define MCP472X_REF_VDD 0x00
33#define MCP472X_REF_VREF_UNBUFFERED 0x02
34#define MCP472X_REF_VREF_BUFFERED 0x03
35
36struct mcp4725_data {
37 struct i2c_client *client;
38 int id;
39 unsigned ref_mode;
40 bool vref_buffered;
41 u16 dac_value;
42 bool powerdown;
43 unsigned powerdown_mode;
44 struct regulator *vdd_reg;
45 struct regulator *vref_reg;
46};
47
48static int mcp4725_suspend(struct device *dev)
49{
50 struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
51 to_i2c_client(dev)));
52 u8 outbuf[2];
53
54 outbuf[0] = (data->powerdown_mode + 1) << 4;
55 outbuf[1] = 0;
56 data->powerdown = true;
57
58 return i2c_master_send(data->client, outbuf, 2);
59}
60
61static int mcp4725_resume(struct device *dev)
62{
63 struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
64 to_i2c_client(dev)));
65 u8 outbuf[2];
66
67
68 outbuf[0] = (data->dac_value >> 8) & 0xf;
69 outbuf[1] = data->dac_value & 0xff;
70 data->powerdown = false;
71
72 return i2c_master_send(data->client, outbuf, 2);
73}
74
75#ifdef CONFIG_PM_SLEEP
76static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
77#define MCP4725_PM_OPS (&mcp4725_pm_ops)
78#else
79#define MCP4725_PM_OPS NULL
80#endif
81
82static ssize_t mcp4725_store_eeprom(struct device *dev,
83 struct device_attribute *attr, const char *buf, size_t len)
84{
85 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
86 struct mcp4725_data *data = iio_priv(indio_dev);
87 int tries = 20;
88 u8 inoutbuf[3];
89 bool state;
90 int ret;
91
92 ret = strtobool(buf, &state);
93 if (ret < 0)
94 return ret;
95
96 if (!state)
97 return 0;
98
99 inoutbuf[0] = 0x60;
100 inoutbuf[0] |= data->ref_mode << 3;
101 inoutbuf[1] = data->dac_value >> 4;
102 inoutbuf[2] = (data->dac_value & 0xf) << 4;
103
104 ret = i2c_master_send(data->client, inoutbuf, 3);
105 if (ret < 0)
106 return ret;
107 else if (ret != 3)
108 return -EIO;
109
110
111 while (tries--) {
112 msleep(20);
113 ret = i2c_master_recv(data->client, inoutbuf, 3);
114 if (ret < 0)
115 return ret;
116 else if (ret != 3)
117 return -EIO;
118
119 if (inoutbuf[0] & 0x80)
120 break;
121 }
122
123 if (tries < 0) {
124 dev_err(&data->client->dev,
125 "mcp4725_store_eeprom() failed, incomplete\n");
126 return -EIO;
127 }
128
129 return len;
130}
131
132static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
133
134static struct attribute *mcp4725_attributes[] = {
135 &iio_dev_attr_store_eeprom.dev_attr.attr,
136 NULL,
137};
138
139static const struct attribute_group mcp4725_attribute_group = {
140 .attrs = mcp4725_attributes,
141};
142
143static const char * const mcp4725_powerdown_modes[] = {
144 "1kohm_to_gnd",
145 "100kohm_to_gnd",
146 "500kohm_to_gnd"
147};
148
149static const char * const mcp4726_powerdown_modes[] = {
150 "1kohm_to_gnd",
151 "125kohm_to_gnd",
152 "640kohm_to_gnd"
153};
154
155static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
156 const struct iio_chan_spec *chan)
157{
158 struct mcp4725_data *data = iio_priv(indio_dev);
159
160 return data->powerdown_mode;
161}
162
163static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
164 const struct iio_chan_spec *chan, unsigned mode)
165{
166 struct mcp4725_data *data = iio_priv(indio_dev);
167
168 data->powerdown_mode = mode;
169
170 return 0;
171}
172
173static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
174 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
175{
176 struct mcp4725_data *data = iio_priv(indio_dev);
177
178 return sprintf(buf, "%d\n", data->powerdown);
179}
180
181static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev,
182 uintptr_t private, const struct iio_chan_spec *chan,
183 const char *buf, size_t len)
184{
185 struct mcp4725_data *data = iio_priv(indio_dev);
186 bool state;
187 int ret;
188
189 ret = strtobool(buf, &state);
190 if (ret)
191 return ret;
192
193 if (state)
194 ret = mcp4725_suspend(&data->client->dev);
195 else
196 ret = mcp4725_resume(&data->client->dev);
197 if (ret < 0)
198 return ret;
199
200 return len;
201}
202
203enum chip_id {
204 MCP4725,
205 MCP4726,
206};
207
208static const struct iio_enum mcp472x_powerdown_mode_enum[] = {
209 [MCP4725] = {
210 .items = mcp4725_powerdown_modes,
211 .num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
212 .get = mcp4725_get_powerdown_mode,
213 .set = mcp4725_set_powerdown_mode,
214 },
215 [MCP4726] = {
216 .items = mcp4726_powerdown_modes,
217 .num_items = ARRAY_SIZE(mcp4726_powerdown_modes),
218 .get = mcp4725_get_powerdown_mode,
219 .set = mcp4725_set_powerdown_mode,
220 },
221};
222
223static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
224 {
225 .name = "powerdown",
226 .read = mcp4725_read_powerdown,
227 .write = mcp4725_write_powerdown,
228 .shared = IIO_SEPARATE,
229 },
230 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
231 &mcp472x_powerdown_mode_enum[MCP4725]),
232 IIO_ENUM_AVAILABLE("powerdown_mode",
233 &mcp472x_powerdown_mode_enum[MCP4725]),
234 { },
235};
236
237static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = {
238 {
239 .name = "powerdown",
240 .read = mcp4725_read_powerdown,
241 .write = mcp4725_write_powerdown,
242 .shared = IIO_SEPARATE,
243 },
244 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
245 &mcp472x_powerdown_mode_enum[MCP4726]),
246 IIO_ENUM_AVAILABLE("powerdown_mode",
247 &mcp472x_powerdown_mode_enum[MCP4726]),
248 { },
249};
250
251static const struct iio_chan_spec mcp472x_channel[] = {
252 [MCP4725] = {
253 .type = IIO_VOLTAGE,
254 .indexed = 1,
255 .output = 1,
256 .channel = 0,
257 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
258 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
259 .ext_info = mcp4725_ext_info,
260 },
261 [MCP4726] = {
262 .type = IIO_VOLTAGE,
263 .indexed = 1,
264 .output = 1,
265 .channel = 0,
266 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
267 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
268 .ext_info = mcp4726_ext_info,
269 },
270};
271
272static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
273{
274 struct mcp4725_data *data = iio_priv(indio_dev);
275 u8 outbuf[2];
276 int ret;
277
278 if (val >= (1 << 12) || val < 0)
279 return -EINVAL;
280
281 outbuf[0] = (val >> 8) & 0xf;
282 outbuf[1] = val & 0xff;
283
284 ret = i2c_master_send(data->client, outbuf, 2);
285 if (ret < 0)
286 return ret;
287 else if (ret != 2)
288 return -EIO;
289 else
290 return 0;
291}
292
293static int mcp4726_set_cfg(struct iio_dev *indio_dev)
294{
295 struct mcp4725_data *data = iio_priv(indio_dev);
296 u8 outbuf[3];
297 int ret;
298
299 outbuf[0] = 0x40;
300 outbuf[0] |= data->ref_mode << 3;
301 if (data->powerdown)
302 outbuf[0] |= data->powerdown << 1;
303 outbuf[1] = data->dac_value >> 4;
304 outbuf[2] = (data->dac_value & 0xf) << 4;
305
306 ret = i2c_master_send(data->client, outbuf, 3);
307 if (ret < 0)
308 return ret;
309 else if (ret != 3)
310 return -EIO;
311 else
312 return 0;
313}
314
315static int mcp4725_read_raw(struct iio_dev *indio_dev,
316 struct iio_chan_spec const *chan,
317 int *val, int *val2, long mask)
318{
319 struct mcp4725_data *data = iio_priv(indio_dev);
320 int ret;
321
322 switch (mask) {
323 case IIO_CHAN_INFO_RAW:
324 *val = data->dac_value;
325 return IIO_VAL_INT;
326 case IIO_CHAN_INFO_SCALE:
327 if (data->ref_mode == MCP472X_REF_VDD)
328 ret = regulator_get_voltage(data->vdd_reg);
329 else
330 ret = regulator_get_voltage(data->vref_reg);
331
332 if (ret < 0)
333 return ret;
334
335 *val = ret / 1000;
336 *val2 = 12;
337 return IIO_VAL_FRACTIONAL_LOG2;
338 }
339 return -EINVAL;
340}
341
342static int mcp4725_write_raw(struct iio_dev *indio_dev,
343 struct iio_chan_spec const *chan,
344 int val, int val2, long mask)
345{
346 struct mcp4725_data *data = iio_priv(indio_dev);
347 int ret;
348
349 switch (mask) {
350 case IIO_CHAN_INFO_RAW:
351 ret = mcp4725_set_value(indio_dev, val);
352 data->dac_value = val;
353 break;
354 default:
355 ret = -EINVAL;
356 break;
357 }
358
359 return ret;
360}
361
362static const struct iio_info mcp4725_info = {
363 .read_raw = mcp4725_read_raw,
364 .write_raw = mcp4725_write_raw,
365 .attrs = &mcp4725_attribute_group,
366};
367
368#ifdef CONFIG_OF
369static int mcp4725_probe_dt(struct device *dev,
370 struct mcp4725_platform_data *pdata)
371{
372 struct device_node *np = dev->of_node;
373
374 if (!np)
375 return -ENODEV;
376
377
378 pdata->use_vref = of_property_read_bool(np, "vref-supply");
379 pdata->vref_buffered =
380 of_property_read_bool(np, "microchip,vref-buffered");
381
382 return 0;
383}
384#else
385static int mcp4725_probe_dt(struct device *dev,
386 struct mcp4725_platform_data *platform_data)
387{
388 return -ENODEV;
389}
390#endif
391
392static int mcp4725_probe(struct i2c_client *client,
393 const struct i2c_device_id *id)
394{
395 struct mcp4725_data *data;
396 struct iio_dev *indio_dev;
397 struct mcp4725_platform_data *pdata, pdata_dt;
398 u8 inbuf[4];
399 u8 pd;
400 u8 ref;
401 int err;
402
403 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
404 if (indio_dev == NULL)
405 return -ENOMEM;
406 data = iio_priv(indio_dev);
407 i2c_set_clientdata(client, indio_dev);
408 data->client = client;
409 if (client->dev.of_node)
410 data->id = (enum chip_id)of_device_get_match_data(&client->dev);
411 else
412 data->id = id->driver_data;
413 pdata = dev_get_platdata(&client->dev);
414
415 if (!pdata) {
416 err = mcp4725_probe_dt(&client->dev, &pdata_dt);
417 if (err) {
418 dev_err(&client->dev,
419 "invalid platform or devicetree data");
420 return err;
421 }
422 pdata = &pdata_dt;
423 }
424
425 if (data->id == MCP4725 && pdata->use_vref) {
426 dev_err(&client->dev,
427 "external reference is unavailable on MCP4725");
428 return -EINVAL;
429 }
430
431 if (!pdata->use_vref && pdata->vref_buffered) {
432 dev_err(&client->dev,
433 "buffering is unavailable on the internal reference");
434 return -EINVAL;
435 }
436
437 if (!pdata->use_vref)
438 data->ref_mode = MCP472X_REF_VDD;
439 else
440 data->ref_mode = pdata->vref_buffered ?
441 MCP472X_REF_VREF_BUFFERED :
442 MCP472X_REF_VREF_UNBUFFERED;
443
444 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
445 if (IS_ERR(data->vdd_reg))
446 return PTR_ERR(data->vdd_reg);
447
448 err = regulator_enable(data->vdd_reg);
449 if (err)
450 return err;
451
452 if (pdata->use_vref) {
453 data->vref_reg = devm_regulator_get(&client->dev, "vref");
454 if (IS_ERR(data->vref_reg)) {
455 err = PTR_ERR(data->vref_reg);
456 goto err_disable_vdd_reg;
457 }
458
459 err = regulator_enable(data->vref_reg);
460 if (err)
461 goto err_disable_vdd_reg;
462 }
463
464 indio_dev->dev.parent = &client->dev;
465 indio_dev->name = id->name;
466 indio_dev->info = &mcp4725_info;
467 indio_dev->channels = &mcp472x_channel[id->driver_data];
468 indio_dev->num_channels = 1;
469 indio_dev->modes = INDIO_DIRECT_MODE;
470
471
472 err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
473
474 if (err < 0) {
475 dev_err(&client->dev, "failed to read DAC value");
476 goto err_disable_vref_reg;
477 }
478 pd = (inbuf[0] >> 1) & 0x3;
479 data->powerdown = pd > 0;
480 data->powerdown_mode = pd ? pd - 1 : 2;
481 data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
482 if (data->id == MCP4726)
483 ref = (inbuf[3] >> 3) & 0x3;
484
485 if (data->id == MCP4726 && ref != data->ref_mode) {
486 dev_info(&client->dev,
487 "voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
488 data->ref_mode, ref, data->ref_mode);
489 err = mcp4726_set_cfg(indio_dev);
490 if (err < 0)
491 goto err_disable_vref_reg;
492 }
493
494 err = iio_device_register(indio_dev);
495 if (err)
496 goto err_disable_vref_reg;
497
498 return 0;
499
500err_disable_vref_reg:
501 if (data->vref_reg)
502 regulator_disable(data->vref_reg);
503
504err_disable_vdd_reg:
505 regulator_disable(data->vdd_reg);
506
507 return err;
508}
509
510static int mcp4725_remove(struct i2c_client *client)
511{
512 struct iio_dev *indio_dev = i2c_get_clientdata(client);
513 struct mcp4725_data *data = iio_priv(indio_dev);
514
515 iio_device_unregister(indio_dev);
516
517 if (data->vref_reg)
518 regulator_disable(data->vref_reg);
519 regulator_disable(data->vdd_reg);
520
521 return 0;
522}
523
524static const struct i2c_device_id mcp4725_id[] = {
525 { "mcp4725", MCP4725 },
526 { "mcp4726", MCP4726 },
527 { }
528};
529MODULE_DEVICE_TABLE(i2c, mcp4725_id);
530
531#ifdef CONFIG_OF
532static const struct of_device_id mcp4725_of_match[] = {
533 {
534 .compatible = "microchip,mcp4725",
535 .data = (void *)MCP4725
536 },
537 {
538 .compatible = "microchip,mcp4726",
539 .data = (void *)MCP4726
540 },
541 { }
542};
543MODULE_DEVICE_TABLE(of, mcp4725_of_match);
544#endif
545
546static struct i2c_driver mcp4725_driver = {
547 .driver = {
548 .name = MCP4725_DRV_NAME,
549 .of_match_table = of_match_ptr(mcp4725_of_match),
550 .pm = MCP4725_PM_OPS,
551 },
552 .probe = mcp4725_probe,
553 .remove = mcp4725_remove,
554 .id_table = mcp4725_id,
555};
556module_i2c_driver(mcp4725_driver);
557
558MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
559MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");
560MODULE_LICENSE("GPL");
561
