2 * mcp4725.c - Support for Microchip MCP4725/6
4 * Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
6 * Based on max517 by Roland Stigge <stigge@antcom.de>
8 * This file is subject to the terms and conditions of version 2 of
9 * the GNU General Public License. See the file COPYING in the main
10 * directory of this archive for more details.
12 * driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
13 * (7-bit I2C slave address 0x60, the three LSBs can be configured in
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>
25 #include <linux/iio/iio.h>
26 #include <linux/iio/sysfs.h>
28 #include <linux/iio/dac/mcp4725.h>
30 #define MCP4725_DRV_NAME "mcp4725"
32 #define MCP472X_REF_VDD 0x00
33 #define MCP472X_REF_VREF_UNBUFFERED 0x02
34 #define MCP472X_REF_VREF_BUFFERED 0x03
37 struct i2c_client *client;
43 unsigned powerdown_mode;
44 struct regulator *vdd_reg;
45 struct regulator *vref_reg;
48 static int __maybe_unused mcp4725_suspend(struct device *dev)
50 struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
54 outbuf[0] = (data->powerdown_mode + 1) << 4;
56 data->powerdown = true;
58 return i2c_master_send(data->client, outbuf, 2);
61 static int __maybe_unused mcp4725_resume(struct device *dev)
63 struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
67 /* restore previous DAC value */
68 outbuf[0] = (data->dac_value >> 8) & 0xf;
69 outbuf[1] = data->dac_value & 0xff;
70 data->powerdown = false;
72 return i2c_master_send(data->client, outbuf, 2);
74 static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
76 static ssize_t mcp4725_store_eeprom(struct device *dev,
77 struct device_attribute *attr, const char *buf, size_t len)
79 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
80 struct mcp4725_data *data = iio_priv(indio_dev);
86 ret = strtobool(buf, &state);
93 inoutbuf[0] = 0x60; /* write EEPROM */
94 inoutbuf[0] |= data->ref_mode << 3;
95 inoutbuf[1] = data->dac_value >> 4;
96 inoutbuf[2] = (data->dac_value & 0xf) << 4;
98 ret = i2c_master_send(data->client, inoutbuf, 3);
104 /* wait for write complete, takes up to 50ms */
107 ret = i2c_master_recv(data->client, inoutbuf, 3);
113 if (inoutbuf[0] & 0x80)
118 dev_err(&data->client->dev,
119 "mcp4725_store_eeprom() failed, incomplete\n");
126 static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
128 static struct attribute *mcp4725_attributes[] = {
129 &iio_dev_attr_store_eeprom.dev_attr.attr,
133 static const struct attribute_group mcp4725_attribute_group = {
134 .attrs = mcp4725_attributes,
137 static const char * const mcp4725_powerdown_modes[] = {
143 static const char * const mcp4726_powerdown_modes[] = {
149 static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
150 const struct iio_chan_spec *chan)
152 struct mcp4725_data *data = iio_priv(indio_dev);
154 return data->powerdown_mode;
157 static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
158 const struct iio_chan_spec *chan, unsigned mode)
160 struct mcp4725_data *data = iio_priv(indio_dev);
162 data->powerdown_mode = mode;
167 static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
168 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
170 struct mcp4725_data *data = iio_priv(indio_dev);
172 return sprintf(buf, "%d\n", data->powerdown);
175 static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev,
176 uintptr_t private, const struct iio_chan_spec *chan,
177 const char *buf, size_t len)
179 struct mcp4725_data *data = iio_priv(indio_dev);
183 ret = strtobool(buf, &state);
188 ret = mcp4725_suspend(&data->client->dev);
190 ret = mcp4725_resume(&data->client->dev);
202 static const struct iio_enum mcp472x_powerdown_mode_enum[] = {
204 .items = mcp4725_powerdown_modes,
205 .num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
206 .get = mcp4725_get_powerdown_mode,
207 .set = mcp4725_set_powerdown_mode,
210 .items = mcp4726_powerdown_modes,
211 .num_items = ARRAY_SIZE(mcp4726_powerdown_modes),
212 .get = mcp4725_get_powerdown_mode,
213 .set = mcp4725_set_powerdown_mode,
217 static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
220 .read = mcp4725_read_powerdown,
221 .write = mcp4725_write_powerdown,
222 .shared = IIO_SEPARATE,
224 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
225 &mcp472x_powerdown_mode_enum[MCP4725]),
226 IIO_ENUM_AVAILABLE("powerdown_mode",
227 &mcp472x_powerdown_mode_enum[MCP4725]),
231 static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = {
234 .read = mcp4725_read_powerdown,
235 .write = mcp4725_write_powerdown,
236 .shared = IIO_SEPARATE,
238 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
239 &mcp472x_powerdown_mode_enum[MCP4726]),
240 IIO_ENUM_AVAILABLE("powerdown_mode",
241 &mcp472x_powerdown_mode_enum[MCP4726]),
245 static const struct iio_chan_spec mcp472x_channel[] = {
251 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
252 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
253 .ext_info = mcp4725_ext_info,
260 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
261 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
262 .ext_info = mcp4726_ext_info,
266 static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
268 struct mcp4725_data *data = iio_priv(indio_dev);
272 if (val >= (1 << 12) || val < 0)
275 outbuf[0] = (val >> 8) & 0xf;
276 outbuf[1] = val & 0xff;
278 ret = i2c_master_send(data->client, outbuf, 2);
287 static int mcp4726_set_cfg(struct iio_dev *indio_dev)
289 struct mcp4725_data *data = iio_priv(indio_dev);
294 outbuf[0] |= data->ref_mode << 3;
296 outbuf[0] |= data->powerdown << 1;
297 outbuf[1] = data->dac_value >> 4;
298 outbuf[2] = (data->dac_value & 0xf) << 4;
300 ret = i2c_master_send(data->client, outbuf, 3);
309 static int mcp4725_read_raw(struct iio_dev *indio_dev,
310 struct iio_chan_spec const *chan,
311 int *val, int *val2, long mask)
313 struct mcp4725_data *data = iio_priv(indio_dev);
317 case IIO_CHAN_INFO_RAW:
318 *val = data->dac_value;
320 case IIO_CHAN_INFO_SCALE:
321 if (data->ref_mode == MCP472X_REF_VDD)
322 ret = regulator_get_voltage(data->vdd_reg);
324 ret = regulator_get_voltage(data->vref_reg);
331 return IIO_VAL_FRACTIONAL_LOG2;
336 static int mcp4725_write_raw(struct iio_dev *indio_dev,
337 struct iio_chan_spec const *chan,
338 int val, int val2, long mask)
340 struct mcp4725_data *data = iio_priv(indio_dev);
344 case IIO_CHAN_INFO_RAW:
345 ret = mcp4725_set_value(indio_dev, val);
346 data->dac_value = val;
356 static const struct iio_info mcp4725_info = {
357 .read_raw = mcp4725_read_raw,
358 .write_raw = mcp4725_write_raw,
359 .attrs = &mcp4725_attribute_group,
363 static int mcp4725_probe_dt(struct device *dev,
364 struct mcp4725_platform_data *pdata)
366 struct device_node *np = dev->of_node;
371 /* check if is the vref-supply defined */
372 pdata->use_vref = of_property_read_bool(np, "vref-supply");
373 pdata->vref_buffered =
374 of_property_read_bool(np, "microchip,vref-buffered");
379 static int mcp4725_probe_dt(struct device *dev,
380 struct mcp4725_platform_data *platform_data)
386 static int mcp4725_probe(struct i2c_client *client,
387 const struct i2c_device_id *id)
389 struct mcp4725_data *data;
390 struct iio_dev *indio_dev;
391 struct mcp4725_platform_data *pdata, pdata_dt;
397 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
398 if (indio_dev == NULL)
400 data = iio_priv(indio_dev);
401 i2c_set_clientdata(client, indio_dev);
402 data->client = client;
403 if (client->dev.of_node)
404 data->id = (enum chip_id)of_device_get_match_data(&client->dev);
406 data->id = id->driver_data;
407 pdata = dev_get_platdata(&client->dev);
410 err = mcp4725_probe_dt(&client->dev, &pdata_dt);
412 dev_err(&client->dev,
413 "invalid platform or devicetree data");
419 if (data->id == MCP4725 && pdata->use_vref) {
420 dev_err(&client->dev,
421 "external reference is unavailable on MCP4725");
425 if (!pdata->use_vref && pdata->vref_buffered) {
426 dev_err(&client->dev,
427 "buffering is unavailable on the internal reference");
431 if (!pdata->use_vref)
432 data->ref_mode = MCP472X_REF_VDD;
434 data->ref_mode = pdata->vref_buffered ?
435 MCP472X_REF_VREF_BUFFERED :
436 MCP472X_REF_VREF_UNBUFFERED;
438 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
439 if (IS_ERR(data->vdd_reg))
440 return PTR_ERR(data->vdd_reg);
442 err = regulator_enable(data->vdd_reg);
446 if (pdata->use_vref) {
447 data->vref_reg = devm_regulator_get(&client->dev, "vref");
448 if (IS_ERR(data->vref_reg)) {
449 err = PTR_ERR(data->vref_reg);
450 goto err_disable_vdd_reg;
453 err = regulator_enable(data->vref_reg);
455 goto err_disable_vdd_reg;
458 indio_dev->dev.parent = &client->dev;
459 indio_dev->name = id->name;
460 indio_dev->info = &mcp4725_info;
461 indio_dev->channels = &mcp472x_channel[id->driver_data];
462 indio_dev->num_channels = 1;
463 indio_dev->modes = INDIO_DIRECT_MODE;
465 /* read current DAC value and settings */
466 err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
469 dev_err(&client->dev, "failed to read DAC value");
470 goto err_disable_vref_reg;
472 pd = (inbuf[0] >> 1) & 0x3;
473 data->powerdown = pd > 0;
474 data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
475 data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
476 if (data->id == MCP4726)
477 ref = (inbuf[3] >> 3) & 0x3;
479 if (data->id == MCP4726 && ref != data->ref_mode) {
480 dev_info(&client->dev,
481 "voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
482 data->ref_mode, ref, data->ref_mode);
483 err = mcp4726_set_cfg(indio_dev);
485 goto err_disable_vref_reg;
488 err = iio_device_register(indio_dev);
490 goto err_disable_vref_reg;
494 err_disable_vref_reg:
496 regulator_disable(data->vref_reg);
499 regulator_disable(data->vdd_reg);
504 static int mcp4725_remove(struct i2c_client *client)
506 struct iio_dev *indio_dev = i2c_get_clientdata(client);
507 struct mcp4725_data *data = iio_priv(indio_dev);
509 iio_device_unregister(indio_dev);
512 regulator_disable(data->vref_reg);
513 regulator_disable(data->vdd_reg);
518 static const struct i2c_device_id mcp4725_id[] = {
519 { "mcp4725", MCP4725 },
520 { "mcp4726", MCP4726 },
523 MODULE_DEVICE_TABLE(i2c, mcp4725_id);
526 static const struct of_device_id mcp4725_of_match[] = {
528 .compatible = "microchip,mcp4725",
529 .data = (void *)MCP4725
532 .compatible = "microchip,mcp4726",
533 .data = (void *)MCP4726
537 MODULE_DEVICE_TABLE(of, mcp4725_of_match);
540 static struct i2c_driver mcp4725_driver = {
542 .name = MCP4725_DRV_NAME,
543 .of_match_table = of_match_ptr(mcp4725_of_match),
544 .pm = &mcp4725_pm_ops,
546 .probe = mcp4725_probe,
547 .remove = mcp4725_remove,
548 .id_table = mcp4725_id,
550 module_i2c_driver(mcp4725_driver);
552 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
553 MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");
554 MODULE_LICENSE("GPL");