1 // SPDX-License-Identifier: GPL-2.0-only
3 * mcp4725.c - Support for Microchip MCP4725/6
5 * Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
7 * Based on max517 by Roland Stigge <stigge@antcom.de>
9 * driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
10 * (7-bit I2C slave address 0x60, the three LSBs can be configured in
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>
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
25 #include <linux/iio/dac/mcp4725.h>
27 #define MCP4725_DRV_NAME "mcp4725"
29 #define MCP472X_REF_VDD 0x00
30 #define MCP472X_REF_VREF_UNBUFFERED 0x02
31 #define MCP472X_REF_VREF_BUFFERED 0x03
34 struct i2c_client *client;
40 unsigned powerdown_mode;
41 struct regulator *vdd_reg;
42 struct regulator *vref_reg;
45 static int mcp4725_suspend(struct device *dev)
47 struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
51 outbuf[0] = (data->powerdown_mode + 1) << 4;
53 data->powerdown = true;
55 return i2c_master_send(data->client, outbuf, 2);
58 static int mcp4725_resume(struct device *dev)
60 struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
64 /* restore previous DAC value */
65 outbuf[0] = (data->dac_value >> 8) & 0xf;
66 outbuf[1] = data->dac_value & 0xff;
67 data->powerdown = false;
69 return i2c_master_send(data->client, outbuf, 2);
71 static DEFINE_SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend,
74 static ssize_t mcp4725_store_eeprom(struct device *dev,
75 struct device_attribute *attr, const char *buf, size_t len)
77 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
78 struct mcp4725_data *data = iio_priv(indio_dev);
84 ret = kstrtobool(buf, &state);
91 inoutbuf[0] = 0x60; /* write EEPROM */
92 inoutbuf[0] |= data->ref_mode << 3;
93 inoutbuf[0] |= data->powerdown ? ((data->powerdown_mode + 1) << 1) : 0;
94 inoutbuf[1] = data->dac_value >> 4;
95 inoutbuf[2] = (data->dac_value & 0xf) << 4;
97 ret = i2c_master_send(data->client, inoutbuf, 3);
103 /* wait for write complete, takes up to 50ms */
106 ret = i2c_master_recv(data->client, inoutbuf, 3);
112 if (inoutbuf[0] & 0x80)
117 dev_err(&data->client->dev,
118 "mcp4725_store_eeprom() failed, incomplete\n");
125 static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
127 static struct attribute *mcp4725_attributes[] = {
128 &iio_dev_attr_store_eeprom.dev_attr.attr,
132 static const struct attribute_group mcp4725_attribute_group = {
133 .attrs = mcp4725_attributes,
136 static const char * const mcp4725_powerdown_modes[] = {
142 static const char * const mcp4726_powerdown_modes[] = {
148 static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
149 const struct iio_chan_spec *chan)
151 struct mcp4725_data *data = iio_priv(indio_dev);
153 return data->powerdown_mode;
156 static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
157 const struct iio_chan_spec *chan, unsigned mode)
159 struct mcp4725_data *data = iio_priv(indio_dev);
161 data->powerdown_mode = mode;
166 static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
167 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
169 struct mcp4725_data *data = iio_priv(indio_dev);
171 return sysfs_emit(buf, "%d\n", data->powerdown);
174 static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev,
175 uintptr_t private, const struct iio_chan_spec *chan,
176 const char *buf, size_t len)
178 struct mcp4725_data *data = iio_priv(indio_dev);
182 ret = kstrtobool(buf, &state);
187 ret = mcp4725_suspend(&data->client->dev);
189 ret = mcp4725_resume(&data->client->dev);
201 static const struct iio_enum mcp472x_powerdown_mode_enum[] = {
203 .items = mcp4725_powerdown_modes,
204 .num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
205 .get = mcp4725_get_powerdown_mode,
206 .set = mcp4725_set_powerdown_mode,
209 .items = mcp4726_powerdown_modes,
210 .num_items = ARRAY_SIZE(mcp4726_powerdown_modes),
211 .get = mcp4725_get_powerdown_mode,
212 .set = mcp4725_set_powerdown_mode,
216 static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
219 .read = mcp4725_read_powerdown,
220 .write = mcp4725_write_powerdown,
221 .shared = IIO_SEPARATE,
223 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
224 &mcp472x_powerdown_mode_enum[MCP4725]),
225 IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE,
226 &mcp472x_powerdown_mode_enum[MCP4725]),
230 static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = {
233 .read = mcp4725_read_powerdown,
234 .write = mcp4725_write_powerdown,
235 .shared = IIO_SEPARATE,
237 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
238 &mcp472x_powerdown_mode_enum[MCP4726]),
239 IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE,
240 &mcp472x_powerdown_mode_enum[MCP4726]),
244 static const struct iio_chan_spec mcp472x_channel[] = {
250 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
251 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
252 .ext_info = mcp4725_ext_info,
259 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
260 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
261 .ext_info = mcp4726_ext_info,
265 static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
267 struct mcp4725_data *data = iio_priv(indio_dev);
271 if (val >= (1 << 12) || val < 0)
274 outbuf[0] = (val >> 8) & 0xf;
275 outbuf[1] = val & 0xff;
277 ret = i2c_master_send(data->client, outbuf, 2);
286 static int mcp4726_set_cfg(struct iio_dev *indio_dev)
288 struct mcp4725_data *data = iio_priv(indio_dev);
293 outbuf[0] |= data->ref_mode << 3;
295 outbuf[0] |= data->powerdown << 1;
296 outbuf[1] = data->dac_value >> 4;
297 outbuf[2] = (data->dac_value & 0xf) << 4;
299 ret = i2c_master_send(data->client, outbuf, 3);
308 static int mcp4725_read_raw(struct iio_dev *indio_dev,
309 struct iio_chan_spec const *chan,
310 int *val, int *val2, long mask)
312 struct mcp4725_data *data = iio_priv(indio_dev);
316 case IIO_CHAN_INFO_RAW:
317 *val = data->dac_value;
319 case IIO_CHAN_INFO_SCALE:
320 if (data->ref_mode == MCP472X_REF_VDD)
321 ret = regulator_get_voltage(data->vdd_reg);
323 ret = regulator_get_voltage(data->vref_reg);
330 return IIO_VAL_FRACTIONAL_LOG2;
335 static int mcp4725_write_raw(struct iio_dev *indio_dev,
336 struct iio_chan_spec const *chan,
337 int val, int val2, long mask)
339 struct mcp4725_data *data = iio_priv(indio_dev);
343 case IIO_CHAN_INFO_RAW:
344 ret = mcp4725_set_value(indio_dev, val);
345 data->dac_value = val;
355 static const struct iio_info mcp4725_info = {
356 .read_raw = mcp4725_read_raw,
357 .write_raw = mcp4725_write_raw,
358 .attrs = &mcp4725_attribute_group,
361 static int mcp4725_probe_dt(struct device *dev,
362 struct mcp4725_platform_data *pdata)
364 /* check if is the vref-supply defined */
365 pdata->use_vref = device_property_read_bool(dev, "vref-supply");
366 pdata->vref_buffered =
367 device_property_read_bool(dev, "microchip,vref-buffered");
372 static int mcp4725_probe(struct i2c_client *client)
374 const struct i2c_device_id *id = i2c_client_get_device_id(client);
375 struct mcp4725_data *data;
376 struct iio_dev *indio_dev;
377 struct mcp4725_platform_data *pdata, pdata_dt;
383 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
384 if (indio_dev == NULL)
386 data = iio_priv(indio_dev);
387 i2c_set_clientdata(client, indio_dev);
388 data->client = client;
389 if (dev_fwnode(&client->dev))
390 data->id = (uintptr_t)device_get_match_data(&client->dev);
392 data->id = id->driver_data;
393 pdata = dev_get_platdata(&client->dev);
396 err = mcp4725_probe_dt(&client->dev, &pdata_dt);
398 dev_err(&client->dev,
399 "invalid platform or devicetree data");
405 if (data->id == MCP4725 && pdata->use_vref) {
406 dev_err(&client->dev,
407 "external reference is unavailable on MCP4725");
411 if (!pdata->use_vref && pdata->vref_buffered) {
412 dev_err(&client->dev,
413 "buffering is unavailable on the internal reference");
417 if (!pdata->use_vref)
418 data->ref_mode = MCP472X_REF_VDD;
420 data->ref_mode = pdata->vref_buffered ?
421 MCP472X_REF_VREF_BUFFERED :
422 MCP472X_REF_VREF_UNBUFFERED;
424 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
425 if (IS_ERR(data->vdd_reg))
426 return PTR_ERR(data->vdd_reg);
428 err = regulator_enable(data->vdd_reg);
432 if (pdata->use_vref) {
433 data->vref_reg = devm_regulator_get(&client->dev, "vref");
434 if (IS_ERR(data->vref_reg)) {
435 err = PTR_ERR(data->vref_reg);
436 goto err_disable_vdd_reg;
439 err = regulator_enable(data->vref_reg);
441 goto err_disable_vdd_reg;
444 indio_dev->name = id->name;
445 indio_dev->info = &mcp4725_info;
446 indio_dev->channels = &mcp472x_channel[id->driver_data];
447 indio_dev->num_channels = 1;
448 indio_dev->modes = INDIO_DIRECT_MODE;
450 /* read current DAC value and settings */
451 err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
454 dev_err(&client->dev, "failed to read DAC value");
455 goto err_disable_vref_reg;
457 pd = (inbuf[0] >> 1) & 0x3;
458 data->powerdown = pd > 0;
459 data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
460 data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
461 if (data->id == MCP4726)
462 ref = (inbuf[3] >> 3) & 0x3;
464 if (data->id == MCP4726 && ref != data->ref_mode) {
465 dev_info(&client->dev,
466 "voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
467 data->ref_mode, ref, data->ref_mode);
468 err = mcp4726_set_cfg(indio_dev);
470 goto err_disable_vref_reg;
473 err = iio_device_register(indio_dev);
475 goto err_disable_vref_reg;
479 err_disable_vref_reg:
481 regulator_disable(data->vref_reg);
484 regulator_disable(data->vdd_reg);
489 static void mcp4725_remove(struct i2c_client *client)
491 struct iio_dev *indio_dev = i2c_get_clientdata(client);
492 struct mcp4725_data *data = iio_priv(indio_dev);
494 iio_device_unregister(indio_dev);
497 regulator_disable(data->vref_reg);
498 regulator_disable(data->vdd_reg);
501 static const struct i2c_device_id mcp4725_id[] = {
502 { "mcp4725", MCP4725 },
503 { "mcp4726", MCP4726 },
506 MODULE_DEVICE_TABLE(i2c, mcp4725_id);
508 static const struct of_device_id mcp4725_of_match[] = {
510 .compatible = "microchip,mcp4725",
511 .data = (void *)MCP4725
514 .compatible = "microchip,mcp4726",
515 .data = (void *)MCP4726
519 MODULE_DEVICE_TABLE(of, mcp4725_of_match);
521 static struct i2c_driver mcp4725_driver = {
523 .name = MCP4725_DRV_NAME,
524 .of_match_table = mcp4725_of_match,
525 .pm = pm_sleep_ptr(&mcp4725_pm_ops),
527 .probe_new = mcp4725_probe,
528 .remove = mcp4725_remove,
529 .id_table = mcp4725_id,
531 module_i2c_driver(mcp4725_driver);
533 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
534 MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");
535 MODULE_LICENSE("GPL");