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[1] = data->dac_value >> 4;
102 inoutbuf[2] = (data->dac_value & 0xf) << 4;
104 ret = i2c_master_send(data->client, inoutbuf, 3);
110 /* wait for write complete, takes up to 50ms */
113 ret = i2c_master_recv(data->client, inoutbuf, 3);
119 if (inoutbuf[0] & 0x80)
124 dev_err(&data->client->dev,
125 "mcp4725_store_eeprom() failed, incomplete\n");
132 static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
134 static struct attribute *mcp4725_attributes[] = {
135 &iio_dev_attr_store_eeprom.dev_attr.attr,
139 static const struct attribute_group mcp4725_attribute_group = {
140 .attrs = mcp4725_attributes,
143 static const char * const mcp4725_powerdown_modes[] = {
149 static const char * const mcp4726_powerdown_modes[] = {
155 static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
156 const struct iio_chan_spec *chan)
158 struct mcp4725_data *data = iio_priv(indio_dev);
160 return data->powerdown_mode;
163 static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
164 const struct iio_chan_spec *chan, unsigned mode)
166 struct mcp4725_data *data = iio_priv(indio_dev);
168 data->powerdown_mode = mode;
173 static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
174 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
176 struct mcp4725_data *data = iio_priv(indio_dev);
178 return sprintf(buf, "%d\n", data->powerdown);
181 static 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)
185 struct mcp4725_data *data = iio_priv(indio_dev);
189 ret = strtobool(buf, &state);
194 ret = mcp4725_suspend(&data->client->dev);
196 ret = mcp4725_resume(&data->client->dev);
208 static const struct iio_enum mcp472x_powerdown_mode_enum[] = {
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,
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,
223 static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
226 .read = mcp4725_read_powerdown,
227 .write = mcp4725_write_powerdown,
228 .shared = IIO_SEPARATE,
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]),
237 static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = {
240 .read = mcp4725_read_powerdown,
241 .write = mcp4725_write_powerdown,
242 .shared = IIO_SEPARATE,
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]),
251 static const struct iio_chan_spec mcp472x_channel[] = {
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,
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,
272 static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
274 struct mcp4725_data *data = iio_priv(indio_dev);
278 if (val >= (1 << 12) || val < 0)
281 outbuf[0] = (val >> 8) & 0xf;
282 outbuf[1] = val & 0xff;
284 ret = i2c_master_send(data->client, outbuf, 2);
293 static int mcp4726_set_cfg(struct iio_dev *indio_dev)
295 struct mcp4725_data *data = iio_priv(indio_dev);
300 outbuf[0] |= data->ref_mode << 3;
302 outbuf[0] |= data->powerdown << 1;
303 outbuf[1] = data->dac_value >> 4;
304 outbuf[2] = (data->dac_value & 0xf) << 4;
306 ret = i2c_master_send(data->client, outbuf, 3);
315 static int mcp4725_read_raw(struct iio_dev *indio_dev,
316 struct iio_chan_spec const *chan,
317 int *val, int *val2, long mask)
319 struct mcp4725_data *data = iio_priv(indio_dev);
323 case IIO_CHAN_INFO_RAW:
324 *val = data->dac_value;
326 case IIO_CHAN_INFO_SCALE:
327 if (data->ref_mode == MCP472X_REF_VDD)
328 ret = regulator_get_voltage(data->vdd_reg);
330 ret = regulator_get_voltage(data->vref_reg);
337 return IIO_VAL_FRACTIONAL_LOG2;
342 static int mcp4725_write_raw(struct iio_dev *indio_dev,
343 struct iio_chan_spec const *chan,
344 int val, int val2, long mask)
346 struct mcp4725_data *data = iio_priv(indio_dev);
350 case IIO_CHAN_INFO_RAW:
351 ret = mcp4725_set_value(indio_dev, val);
352 data->dac_value = val;
362 static const struct iio_info mcp4725_info = {
363 .read_raw = mcp4725_read_raw,
364 .write_raw = mcp4725_write_raw,
365 .attrs = &mcp4725_attribute_group,
369 static int mcp4725_probe_dt(struct device *dev,
370 struct mcp4725_platform_data *pdata)
372 struct device_node *np = dev->of_node;
377 /* check if is the vref-supply defined */
378 pdata->use_vref = of_property_read_bool(np, "vref-supply");
379 pdata->vref_buffered =
380 of_property_read_bool(np, "microchip,vref-buffered");
385 static int mcp4725_probe_dt(struct device *dev,
386 struct mcp4725_platform_data *platform_data)
392 static int mcp4725_probe(struct i2c_client *client,
393 const struct i2c_device_id *id)
395 struct mcp4725_data *data;
396 struct iio_dev *indio_dev;
397 struct mcp4725_platform_data *pdata, pdata_dt;
403 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
404 if (indio_dev == NULL)
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);
412 data->id = id->driver_data;
413 pdata = dev_get_platdata(&client->dev);
416 err = mcp4725_probe_dt(&client->dev, &pdata_dt);
418 dev_err(&client->dev,
419 "invalid platform or devicetree data");
425 if (data->id == MCP4725 && pdata->use_vref) {
426 dev_err(&client->dev,
427 "external reference is unavailable on MCP4725");
431 if (!pdata->use_vref && pdata->vref_buffered) {
432 dev_err(&client->dev,
433 "buffering is unavailable on the internal reference");
437 if (!pdata->use_vref)
438 data->ref_mode = MCP472X_REF_VDD;
440 data->ref_mode = pdata->vref_buffered ?
441 MCP472X_REF_VREF_BUFFERED :
442 MCP472X_REF_VREF_UNBUFFERED;
444 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
445 if (IS_ERR(data->vdd_reg))
446 return PTR_ERR(data->vdd_reg);
448 err = regulator_enable(data->vdd_reg);
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;
459 err = regulator_enable(data->vref_reg);
461 goto err_disable_vdd_reg;
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;
471 /* read current DAC value and settings */
472 err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
475 dev_err(&client->dev, "failed to read DAC value");
476 goto err_disable_vref_reg;
478 pd = (inbuf[0] >> 1) & 0x3;
479 data->powerdown = pd > 0;
480 data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
481 data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
482 if (data->id == MCP4726)
483 ref = (inbuf[3] >> 3) & 0x3;
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);
491 goto err_disable_vref_reg;
494 err = iio_device_register(indio_dev);
496 goto err_disable_vref_reg;
500 err_disable_vref_reg:
502 regulator_disable(data->vref_reg);
505 regulator_disable(data->vdd_reg);
510 static int mcp4725_remove(struct i2c_client *client)
512 struct iio_dev *indio_dev = i2c_get_clientdata(client);
513 struct mcp4725_data *data = iio_priv(indio_dev);
515 iio_device_unregister(indio_dev);
518 regulator_disable(data->vref_reg);
519 regulator_disable(data->vdd_reg);
524 static const struct i2c_device_id mcp4725_id[] = {
525 { "mcp4725", MCP4725 },
526 { "mcp4726", MCP4726 },
529 MODULE_DEVICE_TABLE(i2c, mcp4725_id);
532 static const struct of_device_id mcp4725_of_match[] = {
534 .compatible = "microchip,mcp4725",
535 .data = (void *)MCP4725
538 .compatible = "microchip,mcp4726",
539 .data = (void *)MCP4726
543 MODULE_DEVICE_TABLE(of, mcp4725_of_match);
546 static struct i2c_driver mcp4725_driver = {
548 .name = MCP4725_DRV_NAME,
549 .of_match_table = of_match_ptr(mcp4725_of_match),
550 .pm = MCP4725_PM_OPS,
552 .probe = mcp4725_probe,
553 .remove = mcp4725_remove,
554 .id_table = mcp4725_id,
556 module_i2c_driver(mcp4725_driver);
558 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
559 MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");
560 MODULE_LICENSE("GPL");