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 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 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);
75 #ifdef CONFIG_PM_SLEEP
76 static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
77 #define MCP4725_PM_OPS (&mcp4725_pm_ops)
79 #define MCP4725_PM_OPS NULL
82 static ssize_t mcp4725_store_eeprom(struct device *dev,
83 struct device_attribute *attr, const char *buf, size_t len)
85 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
86 struct mcp4725_data *data = iio_priv(indio_dev);
92 ret = strtobool(buf, &state);
99 inoutbuf[0] = 0x60; /* write EEPROM */
100 inoutbuf[0] |= data->ref_mode << 3;
101 inoutbuf[0] |= data->powerdown ? ((data->powerdown_mode + 1) << 1) : 0;
102 inoutbuf[1] = data->dac_value >> 4;
103 inoutbuf[2] = (data->dac_value & 0xf) << 4;
105 ret = i2c_master_send(data->client, inoutbuf, 3);
111 /* wait for write complete, takes up to 50ms */
114 ret = i2c_master_recv(data->client, inoutbuf, 3);
120 if (inoutbuf[0] & 0x80)
125 dev_err(&data->client->dev,
126 "mcp4725_store_eeprom() failed, incomplete\n");
133 static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
135 static struct attribute *mcp4725_attributes[] = {
136 &iio_dev_attr_store_eeprom.dev_attr.attr,
140 static const struct attribute_group mcp4725_attribute_group = {
141 .attrs = mcp4725_attributes,
144 static const char * const mcp4725_powerdown_modes[] = {
150 static const char * const mcp4726_powerdown_modes[] = {
156 static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
157 const struct iio_chan_spec *chan)
159 struct mcp4725_data *data = iio_priv(indio_dev);
161 return data->powerdown_mode;
164 static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
165 const struct iio_chan_spec *chan, unsigned mode)
167 struct mcp4725_data *data = iio_priv(indio_dev);
169 data->powerdown_mode = mode;
174 static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
175 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
177 struct mcp4725_data *data = iio_priv(indio_dev);
179 return sprintf(buf, "%d\n", data->powerdown);
182 static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev,
183 uintptr_t private, const struct iio_chan_spec *chan,
184 const char *buf, size_t len)
186 struct mcp4725_data *data = iio_priv(indio_dev);
190 ret = strtobool(buf, &state);
195 ret = mcp4725_suspend(&data->client->dev);
197 ret = mcp4725_resume(&data->client->dev);
209 static const struct iio_enum mcp472x_powerdown_mode_enum[] = {
211 .items = mcp4725_powerdown_modes,
212 .num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
213 .get = mcp4725_get_powerdown_mode,
214 .set = mcp4725_set_powerdown_mode,
217 .items = mcp4726_powerdown_modes,
218 .num_items = ARRAY_SIZE(mcp4726_powerdown_modes),
219 .get = mcp4725_get_powerdown_mode,
220 .set = mcp4725_set_powerdown_mode,
224 static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
227 .read = mcp4725_read_powerdown,
228 .write = mcp4725_write_powerdown,
229 .shared = IIO_SEPARATE,
231 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
232 &mcp472x_powerdown_mode_enum[MCP4725]),
233 IIO_ENUM_AVAILABLE("powerdown_mode",
234 &mcp472x_powerdown_mode_enum[MCP4725]),
238 static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = {
241 .read = mcp4725_read_powerdown,
242 .write = mcp4725_write_powerdown,
243 .shared = IIO_SEPARATE,
245 IIO_ENUM("powerdown_mode", IIO_SEPARATE,
246 &mcp472x_powerdown_mode_enum[MCP4726]),
247 IIO_ENUM_AVAILABLE("powerdown_mode",
248 &mcp472x_powerdown_mode_enum[MCP4726]),
252 static const struct iio_chan_spec mcp472x_channel[] = {
258 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
259 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
260 .ext_info = mcp4725_ext_info,
267 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
268 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
269 .ext_info = mcp4726_ext_info,
273 static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
275 struct mcp4725_data *data = iio_priv(indio_dev);
279 if (val >= (1 << 12) || val < 0)
282 outbuf[0] = (val >> 8) & 0xf;
283 outbuf[1] = val & 0xff;
285 ret = i2c_master_send(data->client, outbuf, 2);
294 static int mcp4726_set_cfg(struct iio_dev *indio_dev)
296 struct mcp4725_data *data = iio_priv(indio_dev);
301 outbuf[0] |= data->ref_mode << 3;
303 outbuf[0] |= data->powerdown << 1;
304 outbuf[1] = data->dac_value >> 4;
305 outbuf[2] = (data->dac_value & 0xf) << 4;
307 ret = i2c_master_send(data->client, outbuf, 3);
316 static int mcp4725_read_raw(struct iio_dev *indio_dev,
317 struct iio_chan_spec const *chan,
318 int *val, int *val2, long mask)
320 struct mcp4725_data *data = iio_priv(indio_dev);
324 case IIO_CHAN_INFO_RAW:
325 *val = data->dac_value;
327 case IIO_CHAN_INFO_SCALE:
328 if (data->ref_mode == MCP472X_REF_VDD)
329 ret = regulator_get_voltage(data->vdd_reg);
331 ret = regulator_get_voltage(data->vref_reg);
338 return IIO_VAL_FRACTIONAL_LOG2;
343 static int mcp4725_write_raw(struct iio_dev *indio_dev,
344 struct iio_chan_spec const *chan,
345 int val, int val2, long mask)
347 struct mcp4725_data *data = iio_priv(indio_dev);
351 case IIO_CHAN_INFO_RAW:
352 ret = mcp4725_set_value(indio_dev, val);
353 data->dac_value = val;
363 static const struct iio_info mcp4725_info = {
364 .read_raw = mcp4725_read_raw,
365 .write_raw = mcp4725_write_raw,
366 .attrs = &mcp4725_attribute_group,
367 .driver_module = THIS_MODULE,
371 static int mcp4725_probe_dt(struct device *dev,
372 struct mcp4725_platform_data *pdata)
374 struct device_node *np = dev->of_node;
379 /* check if is the vref-supply defined */
380 pdata->use_vref = of_property_read_bool(np, "vref-supply");
381 pdata->vref_buffered =
382 of_property_read_bool(np, "microchip,vref-buffered");
387 static int mcp4725_probe_dt(struct device *dev,
388 struct mcp4725_platform_data *platform_data)
394 static int mcp4725_probe(struct i2c_client *client,
395 const struct i2c_device_id *id)
397 struct mcp4725_data *data;
398 struct iio_dev *indio_dev;
399 struct mcp4725_platform_data *pdata, pdata_dt;
405 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
406 if (indio_dev == NULL)
408 data = iio_priv(indio_dev);
409 i2c_set_clientdata(client, indio_dev);
410 data->client = client;
411 if (client->dev.of_node)
412 data->id = (enum chip_id)of_device_get_match_data(&client->dev);
414 data->id = id->driver_data;
415 pdata = dev_get_platdata(&client->dev);
418 err = mcp4725_probe_dt(&client->dev, &pdata_dt);
420 dev_err(&client->dev,
421 "invalid platform or devicetree data");
427 if (data->id == MCP4725 && pdata->use_vref) {
428 dev_err(&client->dev,
429 "external reference is unavailable on MCP4725");
433 if (!pdata->use_vref && pdata->vref_buffered) {
434 dev_err(&client->dev,
435 "buffering is unavailable on the internal reference");
439 if (!pdata->use_vref)
440 data->ref_mode = MCP472X_REF_VDD;
442 data->ref_mode = pdata->vref_buffered ?
443 MCP472X_REF_VREF_BUFFERED :
444 MCP472X_REF_VREF_UNBUFFERED;
446 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
447 if (IS_ERR(data->vdd_reg))
448 return PTR_ERR(data->vdd_reg);
450 err = regulator_enable(data->vdd_reg);
454 if (pdata->use_vref) {
455 data->vref_reg = devm_regulator_get(&client->dev, "vref");
456 if (IS_ERR(data->vref_reg)) {
457 err = PTR_ERR(data->vref_reg);
458 goto err_disable_vdd_reg;
461 err = regulator_enable(data->vref_reg);
463 goto err_disable_vdd_reg;
466 indio_dev->dev.parent = &client->dev;
467 indio_dev->name = id->name;
468 indio_dev->info = &mcp4725_info;
469 indio_dev->channels = &mcp472x_channel[id->driver_data];
470 indio_dev->num_channels = 1;
471 indio_dev->modes = INDIO_DIRECT_MODE;
473 /* read current DAC value and settings */
474 err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
477 dev_err(&client->dev, "failed to read DAC value");
478 goto err_disable_vref_reg;
480 pd = (inbuf[0] >> 1) & 0x3;
481 data->powerdown = pd > 0 ? true : false;
482 data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
483 data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
484 if (data->id == MCP4726)
485 ref = (inbuf[3] >> 3) & 0x3;
487 if (data->id == MCP4726 && ref != data->ref_mode) {
488 dev_info(&client->dev,
489 "voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
490 data->ref_mode, ref, data->ref_mode);
491 err = mcp4726_set_cfg(indio_dev);
493 goto err_disable_vref_reg;
496 err = iio_device_register(indio_dev);
498 goto err_disable_vref_reg;
502 err_disable_vref_reg:
504 regulator_disable(data->vref_reg);
507 regulator_disable(data->vdd_reg);
512 static int mcp4725_remove(struct i2c_client *client)
514 struct iio_dev *indio_dev = i2c_get_clientdata(client);
515 struct mcp4725_data *data = iio_priv(indio_dev);
517 iio_device_unregister(indio_dev);
520 regulator_disable(data->vref_reg);
521 regulator_disable(data->vdd_reg);
526 static const struct i2c_device_id mcp4725_id[] = {
527 { "mcp4725", MCP4725 },
528 { "mcp4726", MCP4726 },
531 MODULE_DEVICE_TABLE(i2c, mcp4725_id);
534 static const struct of_device_id mcp4725_of_match[] = {
536 .compatible = "microchip,mcp4725",
537 .data = (void *)MCP4725
540 .compatible = "microchip,mcp4726",
541 .data = (void *)MCP4726
545 MODULE_DEVICE_TABLE(of, mcp4725_of_match);
548 static struct i2c_driver mcp4725_driver = {
550 .name = MCP4725_DRV_NAME,
551 .of_match_table = of_match_ptr(mcp4725_of_match),
552 .pm = MCP4725_PM_OPS,
554 .probe = mcp4725_probe,
555 .remove = mcp4725_remove,
556 .id_table = mcp4725_id,
558 module_i2c_driver(mcp4725_driver);
560 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
561 MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");
562 MODULE_LICENSE("GPL");