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");