2 * AD7291 8-Channel, I2C, 12-Bit SAR ADC with Temperature Sensor
4 * Copyright 2010-2011 Analog Devices Inc.
6 * Licensed under the GPL-2 or later.
9 #include <linux/interrupt.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/i2c.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/err.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/events.h>
29 * If no events enabled - single polled channel read
30 * If event enabled direct reads disable unless channel
31 * is in the read mask.
33 * The noise-delayed bit as per datasheet suggestion is always enabled.
38 * AD7291 registers definition
40 #define AD7291_COMMAND 0x00
41 #define AD7291_VOLTAGE 0x01
42 #define AD7291_T_SENSE 0x02
43 #define AD7291_T_AVERAGE 0x03
44 #define AD7291_DATA_HIGH(x) ((x) * 3 + 0x4)
45 #define AD7291_DATA_LOW(x) ((x) * 3 + 0x5)
46 #define AD7291_HYST(x) ((x) * 3 + 0x6)
47 #define AD7291_VOLTAGE_ALERT_STATUS 0x1F
48 #define AD7291_T_ALERT_STATUS 0x20
50 #define AD7291_VOLTAGE_LIMIT_COUNT 8
56 #define AD7291_AUTOCYCLE (1 << 0)
57 #define AD7291_RESET (1 << 1)
58 #define AD7291_ALERT_CLEAR (1 << 2)
59 #define AD7291_ALERT_POLARITY (1 << 3)
60 #define AD7291_EXT_REF (1 << 4)
61 #define AD7291_NOISE_DELAY (1 << 5)
62 #define AD7291_T_SENSE_MASK (1 << 7)
63 #define AD7291_VOLTAGE_MASK 0xFF00
64 #define AD7291_VOLTAGE_OFFSET 0x8
69 #define AD7291_CHANNEL_MASK 0xF000
70 #define AD7291_BITS 12
71 #define AD7291_VALUE_MASK 0xFFF
72 #define AD7291_T_VALUE_SIGN 0x400
73 #define AD7291_T_VALUE_FLOAT_OFFSET 2
74 #define AD7291_T_VALUE_FLOAT_MASK 0x2
76 #define AD7291_BITS 12
78 struct ad7291_chip_info
{
79 struct i2c_client
*client
;
80 struct regulator
*reg
;
82 u16 c_mask
; /* Active voltage channels for events */
83 struct mutex state_lock
;
86 static int ad7291_i2c_read(struct ad7291_chip_info
*chip
, u8 reg
, u16
*data
)
88 struct i2c_client
*client
= chip
->client
;
91 ret
= i2c_smbus_read_word_swapped(client
, reg
);
93 dev_err(&client
->dev
, "I2C read error\n");
102 static int ad7291_i2c_write(struct ad7291_chip_info
*chip
, u8 reg
, u16 data
)
104 return i2c_smbus_write_word_swapped(chip
->client
, reg
, data
);
107 static irqreturn_t
ad7291_event_handler(int irq
, void *private)
109 struct iio_dev
*indio_dev
= private;
110 struct ad7291_chip_info
*chip
= iio_priv(private);
111 u16 t_status
, v_status
;
114 s64 timestamp
= iio_get_time_ns();
116 if (ad7291_i2c_read(chip
, AD7291_T_ALERT_STATUS
, &t_status
))
119 if (ad7291_i2c_read(chip
, AD7291_VOLTAGE_ALERT_STATUS
, &v_status
))
122 if (!(t_status
|| v_status
))
125 command
= chip
->command
| AD7291_ALERT_CLEAR
;
126 ad7291_i2c_write(chip
, AD7291_COMMAND
, command
);
128 command
= chip
->command
& ~AD7291_ALERT_CLEAR
;
129 ad7291_i2c_write(chip
, AD7291_COMMAND
, command
);
131 /* For now treat t_sense and t_sense_average the same */
132 if ((t_status
& (1 << 0)) || (t_status
& (1 << 2)))
133 iio_push_event(indio_dev
,
134 IIO_UNMOD_EVENT_CODE(IIO_TEMP
,
139 if ((t_status
& (1 << 1)) || (t_status
& (1 << 3)))
140 iio_push_event(indio_dev
,
141 IIO_UNMOD_EVENT_CODE(IIO_TEMP
,
147 for (i
= 0; i
< AD7291_VOLTAGE_LIMIT_COUNT
*2; i
+= 2) {
148 if (v_status
& (1 << i
))
149 iio_push_event(indio_dev
,
150 IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE
,
155 if (v_status
& (1 << (i
+ 1)))
156 iio_push_event(indio_dev
,
157 IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE
,
167 static inline ssize_t
ad7291_show_hyst(struct device
*dev
,
168 struct device_attribute
*attr
,
171 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
172 struct ad7291_chip_info
*chip
= iio_priv(indio_dev
);
173 struct iio_dev_attr
*this_attr
= to_iio_dev_attr(attr
);
177 ret
= ad7291_i2c_read(chip
, this_attr
->address
, &data
);
181 return sprintf(buf
, "%d\n", data
& AD7291_VALUE_MASK
);
184 static inline ssize_t
ad7291_set_hyst(struct device
*dev
,
185 struct device_attribute
*attr
,
189 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
190 struct ad7291_chip_info
*chip
= iio_priv(indio_dev
);
191 struct iio_dev_attr
*this_attr
= to_iio_dev_attr(attr
);
195 ret
= kstrtou16(buf
, 10, &data
);
199 if (data
> AD7291_VALUE_MASK
)
202 ret
= ad7291_i2c_write(chip
, this_attr
->address
, data
);
209 static IIO_DEVICE_ATTR(in_temp0_thresh_both_hyst_raw
,
211 ad7291_show_hyst
, ad7291_set_hyst
,
213 static IIO_DEVICE_ATTR(in_voltage0_thresh_both_hyst_raw
,
215 ad7291_show_hyst
, ad7291_set_hyst
, AD7291_HYST(0));
216 static IIO_DEVICE_ATTR(in_voltage1_thresh_both_hyst_raw
,
218 ad7291_show_hyst
, ad7291_set_hyst
, AD7291_HYST(1));
219 static IIO_DEVICE_ATTR(in_voltage2_thresh_both_hyst_raw
,
221 ad7291_show_hyst
, ad7291_set_hyst
, AD7291_HYST(2));
222 static IIO_DEVICE_ATTR(in_voltage3_thresh_both_hyst_raw
,
224 ad7291_show_hyst
, ad7291_set_hyst
, AD7291_HYST(3));
225 static IIO_DEVICE_ATTR(in_voltage4_thresh_both_hyst_raw
,
227 ad7291_show_hyst
, ad7291_set_hyst
, AD7291_HYST(4));
228 static IIO_DEVICE_ATTR(in_voltage5_thresh_both_hyst_raw
,
230 ad7291_show_hyst
, ad7291_set_hyst
, AD7291_HYST(5));
231 static IIO_DEVICE_ATTR(in_voltage6_thresh_both_hyst_raw
,
233 ad7291_show_hyst
, ad7291_set_hyst
, AD7291_HYST(6));
234 static IIO_DEVICE_ATTR(in_voltage7_thresh_both_hyst_raw
,
236 ad7291_show_hyst
, ad7291_set_hyst
, AD7291_HYST(7));
238 static struct attribute
*ad7291_event_attributes
[] = {
239 &iio_dev_attr_in_temp0_thresh_both_hyst_raw
.dev_attr
.attr
,
240 &iio_dev_attr_in_voltage0_thresh_both_hyst_raw
.dev_attr
.attr
,
241 &iio_dev_attr_in_voltage1_thresh_both_hyst_raw
.dev_attr
.attr
,
242 &iio_dev_attr_in_voltage2_thresh_both_hyst_raw
.dev_attr
.attr
,
243 &iio_dev_attr_in_voltage3_thresh_both_hyst_raw
.dev_attr
.attr
,
244 &iio_dev_attr_in_voltage4_thresh_both_hyst_raw
.dev_attr
.attr
,
245 &iio_dev_attr_in_voltage5_thresh_both_hyst_raw
.dev_attr
.attr
,
246 &iio_dev_attr_in_voltage6_thresh_both_hyst_raw
.dev_attr
.attr
,
247 &iio_dev_attr_in_voltage7_thresh_both_hyst_raw
.dev_attr
.attr
,
251 static unsigned int ad7291_threshold_reg(u64 event_code
)
255 switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code
)) {
257 offset
= IIO_EVENT_CODE_EXTRACT_CHAN(event_code
);
266 if (IIO_EVENT_CODE_EXTRACT_DIR(event_code
) == IIO_EV_DIR_FALLING
)
267 return AD7291_DATA_LOW(offset
);
269 return AD7291_DATA_HIGH(offset
);
272 static int ad7291_read_event_value(struct iio_dev
*indio_dev
,
276 struct ad7291_chip_info
*chip
= iio_priv(indio_dev
);
280 ret
= ad7291_i2c_read(chip
, ad7291_threshold_reg(event_code
), &uval
);
284 switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code
)) {
286 *val
= uval
& AD7291_VALUE_MASK
;
289 *val
= sign_extend32(uval
, 11);
296 static int ad7291_write_event_value(struct iio_dev
*indio_dev
,
300 struct ad7291_chip_info
*chip
= iio_priv(indio_dev
);
302 switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code
)) {
304 if (val
> AD7291_VALUE_MASK
|| val
< 0)
308 if (val
> 2047 || val
< -2048)
315 return ad7291_i2c_write(chip
, ad7291_threshold_reg(event_code
), val
);
318 static int ad7291_read_event_config(struct iio_dev
*indio_dev
,
321 struct ad7291_chip_info
*chip
= iio_priv(indio_dev
);
322 /* To be enabled the channel must simply be on. If any are enabled
323 we are in continuous sampling mode */
325 switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code
)) {
328 (1 << (15 - IIO_EVENT_CODE_EXTRACT_CHAN(event_code
))))
341 static int ad7291_write_event_config(struct iio_dev
*indio_dev
,
346 struct ad7291_chip_info
*chip
= iio_priv(indio_dev
);
349 mutex_lock(&chip
->state_lock
);
350 regval
= chip
->command
;
352 * To be enabled the channel must simply be on. If any are enabled
353 * use continuous sampling mode.
354 * Possible to disable temp as well but that makes single read tricky.
357 switch (IIO_EVENT_CODE_EXTRACT_TYPE(event_code
)) {
359 if ((!state
) && (chip
->c_mask
& (1 << (15 -
360 IIO_EVENT_CODE_EXTRACT_CHAN(event_code
)))))
361 chip
->c_mask
&= ~(1 << (15 - IIO_EVENT_CODE_EXTRACT_CHAN
363 else if (state
&& (!(chip
->c_mask
& (1 << (15 -
364 IIO_EVENT_CODE_EXTRACT_CHAN(event_code
))))))
365 chip
->c_mask
|= (1 << (15 - IIO_EVENT_CODE_EXTRACT_CHAN
370 regval
&= ~AD7291_AUTOCYCLE
;
371 regval
|= chip
->c_mask
;
372 if (chip
->c_mask
) /* Enable autocycle? */
373 regval
|= AD7291_AUTOCYCLE
;
375 ret
= ad7291_i2c_write(chip
, AD7291_COMMAND
, regval
);
379 chip
->command
= regval
;
386 mutex_unlock(&chip
->state_lock
);
390 static int ad7291_read_raw(struct iio_dev
*indio_dev
,
391 struct iio_chan_spec
const *chan
,
397 struct ad7291_chip_info
*chip
= iio_priv(indio_dev
);
401 case IIO_CHAN_INFO_RAW
:
402 switch (chan
->type
) {
404 mutex_lock(&chip
->state_lock
);
405 /* If in autocycle mode drop through */
406 if (chip
->command
& AD7291_AUTOCYCLE
) {
407 mutex_unlock(&chip
->state_lock
);
410 /* Enable this channel alone */
411 regval
= chip
->command
& (~AD7291_VOLTAGE_MASK
);
412 regval
|= 1 << (15 - chan
->channel
);
413 ret
= ad7291_i2c_write(chip
, AD7291_COMMAND
, regval
);
415 mutex_unlock(&chip
->state_lock
);
419 ret
= i2c_smbus_read_word_swapped(chip
->client
,
422 mutex_unlock(&chip
->state_lock
);
425 *val
= ret
& AD7291_VALUE_MASK
;
426 mutex_unlock(&chip
->state_lock
);
429 /* Assumes tsense bit of command register always set */
430 ret
= i2c_smbus_read_word_swapped(chip
->client
,
434 *val
= sign_extend32(ret
, 11);
439 case IIO_CHAN_INFO_AVERAGE_RAW
:
440 ret
= i2c_smbus_read_word_swapped(chip
->client
,
444 *val
= sign_extend32(ret
, 11);
446 case IIO_CHAN_INFO_SCALE
:
447 switch (chan
->type
) {
451 vref
= regulator_get_voltage(chip
->reg
);
459 return IIO_VAL_FRACTIONAL_LOG2
;
462 * One LSB of the ADC corresponds to 0.25 deg C.
463 * The temperature reading is in 12-bit twos
476 #define AD7291_VOLTAGE_CHAN(_chan) \
478 .type = IIO_VOLTAGE, \
479 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
480 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
483 .event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING)|\
484 IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_FALLING) \
487 static const struct iio_chan_spec ad7291_channels
[] = {
488 AD7291_VOLTAGE_CHAN(0),
489 AD7291_VOLTAGE_CHAN(1),
490 AD7291_VOLTAGE_CHAN(2),
491 AD7291_VOLTAGE_CHAN(3),
492 AD7291_VOLTAGE_CHAN(4),
493 AD7291_VOLTAGE_CHAN(5),
494 AD7291_VOLTAGE_CHAN(6),
495 AD7291_VOLTAGE_CHAN(7),
498 .info_mask_separate
= BIT(IIO_CHAN_INFO_RAW
) |
499 BIT(IIO_CHAN_INFO_AVERAGE_RAW
) |
500 BIT(IIO_CHAN_INFO_SCALE
),
504 IIO_EV_BIT(IIO_EV_TYPE_THRESH
, IIO_EV_DIR_RISING
)|
505 IIO_EV_BIT(IIO_EV_TYPE_THRESH
, IIO_EV_DIR_FALLING
)
509 static struct attribute_group ad7291_event_attribute_group
= {
510 .attrs
= ad7291_event_attributes
,
513 static const struct iio_info ad7291_info
= {
514 .read_raw
= &ad7291_read_raw
,
515 .read_event_config
= &ad7291_read_event_config
,
516 .write_event_config
= &ad7291_write_event_config
,
517 .read_event_value
= &ad7291_read_event_value
,
518 .write_event_value
= &ad7291_write_event_value
,
519 .event_attrs
= &ad7291_event_attribute_group
,
520 .driver_module
= THIS_MODULE
,
523 static int ad7291_probe(struct i2c_client
*client
,
524 const struct i2c_device_id
*id
)
526 struct ad7291_platform_data
*pdata
= client
->dev
.platform_data
;
527 struct ad7291_chip_info
*chip
;
528 struct iio_dev
*indio_dev
;
531 indio_dev
= iio_device_alloc(sizeof(*chip
));
532 if (indio_dev
== NULL
) {
536 chip
= iio_priv(indio_dev
);
538 if (pdata
&& pdata
->use_external_ref
) {
539 chip
->reg
= regulator_get(&client
->dev
, "vref");
540 if (IS_ERR(chip
->reg
))
543 ret
= regulator_enable(chip
->reg
);
548 mutex_init(&chip
->state_lock
);
549 /* this is only used for device removal purposes */
550 i2c_set_clientdata(client
, indio_dev
);
552 chip
->client
= client
;
554 chip
->command
= AD7291_NOISE_DELAY
|
555 AD7291_T_SENSE_MASK
| /* Tsense always enabled */
556 AD7291_ALERT_POLARITY
; /* set irq polarity low level */
558 if (pdata
&& pdata
->use_external_ref
)
559 chip
->command
|= AD7291_EXT_REF
;
561 indio_dev
->name
= id
->name
;
562 indio_dev
->channels
= ad7291_channels
;
563 indio_dev
->num_channels
= ARRAY_SIZE(ad7291_channels
);
565 indio_dev
->dev
.parent
= &client
->dev
;
566 indio_dev
->info
= &ad7291_info
;
567 indio_dev
->modes
= INDIO_DIRECT_MODE
;
569 ret
= ad7291_i2c_write(chip
, AD7291_COMMAND
, AD7291_RESET
);
572 goto error_disable_reg
;
575 ret
= ad7291_i2c_write(chip
, AD7291_COMMAND
, chip
->command
);
578 goto error_disable_reg
;
581 if (client
->irq
> 0) {
582 ret
= request_threaded_irq(client
->irq
,
584 &ad7291_event_handler
,
585 IRQF_TRIGGER_LOW
| IRQF_ONESHOT
,
589 goto error_disable_reg
;
592 ret
= iio_device_register(indio_dev
);
594 goto error_unreg_irq
;
600 free_irq(client
->irq
, indio_dev
);
603 regulator_disable(chip
->reg
);
606 regulator_put(chip
->reg
);
608 iio_device_free(indio_dev
);
613 static int ad7291_remove(struct i2c_client
*client
)
615 struct iio_dev
*indio_dev
= i2c_get_clientdata(client
);
616 struct ad7291_chip_info
*chip
= iio_priv(indio_dev
);
618 iio_device_unregister(indio_dev
);
621 free_irq(client
->irq
, indio_dev
);
624 regulator_disable(chip
->reg
);
625 regulator_put(chip
->reg
);
628 iio_device_free(indio_dev
);
633 static const struct i2c_device_id ad7291_id
[] = {
638 MODULE_DEVICE_TABLE(i2c
, ad7291_id
);
640 static struct i2c_driver ad7291_driver
= {
642 .name
= KBUILD_MODNAME
,
644 .probe
= ad7291_probe
,
645 .remove
= ad7291_remove
,
646 .id_table
= ad7291_id
,
648 module_i2c_driver(ad7291_driver
);
650 MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
651 MODULE_DESCRIPTION("Analog Devices AD7291 ADC driver");
652 MODULE_LICENSE("GPL v2");