mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
589 lines
14 KiB
589 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* AD7291 8-Channel, I2C, 12-Bit SAR ADC with Temperature Sensor |
|
* |
|
* Copyright 2010-2011 Analog Devices Inc. |
|
*/ |
|
|
|
#include <linux/device.h> |
|
#include <linux/err.h> |
|
#include <linux/i2c.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/kernel.h> |
|
#include <linux/module.h> |
|
#include <linux/mutex.h> |
|
#include <linux/regulator/consumer.h> |
|
#include <linux/slab.h> |
|
#include <linux/sysfs.h> |
|
|
|
#include <linux/iio/iio.h> |
|
#include <linux/iio/sysfs.h> |
|
#include <linux/iio/events.h> |
|
|
|
/* |
|
* Simplified handling |
|
* |
|
* If no events enabled - single polled channel read |
|
* If event enabled direct reads disable unless channel |
|
* is in the read mask. |
|
* |
|
* The noise-delayed bit as per datasheet suggestion is always enabled. |
|
*/ |
|
|
|
/* |
|
* AD7291 registers definition |
|
*/ |
|
#define AD7291_COMMAND 0x00 |
|
#define AD7291_VOLTAGE 0x01 |
|
#define AD7291_T_SENSE 0x02 |
|
#define AD7291_T_AVERAGE 0x03 |
|
#define AD7291_DATA_HIGH(x) ((x) * 3 + 0x4) |
|
#define AD7291_DATA_LOW(x) ((x) * 3 + 0x5) |
|
#define AD7291_HYST(x) ((x) * 3 + 0x6) |
|
#define AD7291_VOLTAGE_ALERT_STATUS 0x1F |
|
#define AD7291_T_ALERT_STATUS 0x20 |
|
|
|
#define AD7291_BITS 12 |
|
#define AD7291_VOLTAGE_LIMIT_COUNT 8 |
|
|
|
|
|
/* |
|
* AD7291 command |
|
*/ |
|
#define AD7291_AUTOCYCLE BIT(0) |
|
#define AD7291_RESET BIT(1) |
|
#define AD7291_ALERT_CLEAR BIT(2) |
|
#define AD7291_ALERT_POLARITY BIT(3) |
|
#define AD7291_EXT_REF BIT(4) |
|
#define AD7291_NOISE_DELAY BIT(5) |
|
#define AD7291_T_SENSE_MASK BIT(7) |
|
#define AD7291_VOLTAGE_MASK GENMASK(15, 8) |
|
#define AD7291_VOLTAGE_OFFSET 8 |
|
|
|
/* |
|
* AD7291 value masks |
|
*/ |
|
#define AD7291_VALUE_MASK GENMASK(11, 0) |
|
|
|
/* |
|
* AD7291 alert register bits |
|
*/ |
|
#define AD7291_T_LOW BIT(0) |
|
#define AD7291_T_HIGH BIT(1) |
|
#define AD7291_T_AVG_LOW BIT(2) |
|
#define AD7291_T_AVG_HIGH BIT(3) |
|
#define AD7291_V_LOW(x) BIT((x) * 2) |
|
#define AD7291_V_HIGH(x) BIT((x) * 2 + 1) |
|
|
|
|
|
struct ad7291_chip_info { |
|
struct i2c_client *client; |
|
struct regulator *reg; |
|
u16 command; |
|
u16 c_mask; /* Active voltage channels for events */ |
|
struct mutex state_lock; |
|
}; |
|
|
|
static int ad7291_i2c_read(struct ad7291_chip_info *chip, u8 reg, u16 *data) |
|
{ |
|
struct i2c_client *client = chip->client; |
|
int ret = 0; |
|
|
|
ret = i2c_smbus_read_word_swapped(client, reg); |
|
if (ret < 0) { |
|
dev_err(&client->dev, "I2C read error\n"); |
|
return ret; |
|
} |
|
|
|
*data = ret; |
|
|
|
return 0; |
|
} |
|
|
|
static int ad7291_i2c_write(struct ad7291_chip_info *chip, u8 reg, u16 data) |
|
{ |
|
return i2c_smbus_write_word_swapped(chip->client, reg, data); |
|
} |
|
|
|
static irqreturn_t ad7291_event_handler(int irq, void *private) |
|
{ |
|
struct iio_dev *indio_dev = private; |
|
struct ad7291_chip_info *chip = iio_priv(private); |
|
u16 t_status, v_status; |
|
u16 command; |
|
int i; |
|
s64 timestamp = iio_get_time_ns(indio_dev); |
|
|
|
if (ad7291_i2c_read(chip, AD7291_T_ALERT_STATUS, &t_status)) |
|
return IRQ_HANDLED; |
|
|
|
if (ad7291_i2c_read(chip, AD7291_VOLTAGE_ALERT_STATUS, &v_status)) |
|
return IRQ_HANDLED; |
|
|
|
if (!(t_status || v_status)) |
|
return IRQ_HANDLED; |
|
|
|
command = chip->command | AD7291_ALERT_CLEAR; |
|
ad7291_i2c_write(chip, AD7291_COMMAND, command); |
|
|
|
command = chip->command & ~AD7291_ALERT_CLEAR; |
|
ad7291_i2c_write(chip, AD7291_COMMAND, command); |
|
|
|
/* For now treat t_sense and t_sense_average the same */ |
|
if ((t_status & AD7291_T_LOW) || (t_status & AD7291_T_AVG_LOW)) |
|
iio_push_event(indio_dev, |
|
IIO_UNMOD_EVENT_CODE(IIO_TEMP, |
|
0, |
|
IIO_EV_TYPE_THRESH, |
|
IIO_EV_DIR_FALLING), |
|
timestamp); |
|
if ((t_status & AD7291_T_HIGH) || (t_status & AD7291_T_AVG_HIGH)) |
|
iio_push_event(indio_dev, |
|
IIO_UNMOD_EVENT_CODE(IIO_TEMP, |
|
0, |
|
IIO_EV_TYPE_THRESH, |
|
IIO_EV_DIR_RISING), |
|
timestamp); |
|
|
|
for (i = 0; i < AD7291_VOLTAGE_LIMIT_COUNT; i++) { |
|
if (v_status & AD7291_V_LOW(i)) |
|
iio_push_event(indio_dev, |
|
IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, |
|
i, |
|
IIO_EV_TYPE_THRESH, |
|
IIO_EV_DIR_FALLING), |
|
timestamp); |
|
if (v_status & AD7291_V_HIGH(i)) |
|
iio_push_event(indio_dev, |
|
IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, |
|
i, |
|
IIO_EV_TYPE_THRESH, |
|
IIO_EV_DIR_RISING), |
|
timestamp); |
|
} |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
static unsigned int ad7291_threshold_reg(const struct iio_chan_spec *chan, |
|
enum iio_event_direction dir, |
|
enum iio_event_info info) |
|
{ |
|
unsigned int offset; |
|
|
|
switch (chan->type) { |
|
case IIO_VOLTAGE: |
|
offset = chan->channel; |
|
break; |
|
case IIO_TEMP: |
|
offset = AD7291_VOLTAGE_OFFSET; |
|
break; |
|
default: |
|
return 0; |
|
} |
|
|
|
switch (info) { |
|
case IIO_EV_INFO_VALUE: |
|
if (dir == IIO_EV_DIR_FALLING) |
|
return AD7291_DATA_HIGH(offset); |
|
else |
|
return AD7291_DATA_LOW(offset); |
|
case IIO_EV_INFO_HYSTERESIS: |
|
return AD7291_HYST(offset); |
|
default: |
|
break; |
|
} |
|
return 0; |
|
} |
|
|
|
static int ad7291_read_event_value(struct iio_dev *indio_dev, |
|
const struct iio_chan_spec *chan, |
|
enum iio_event_type type, |
|
enum iio_event_direction dir, |
|
enum iio_event_info info, |
|
int *val, int *val2) |
|
{ |
|
struct ad7291_chip_info *chip = iio_priv(indio_dev); |
|
int ret; |
|
u16 uval; |
|
|
|
ret = ad7291_i2c_read(chip, ad7291_threshold_reg(chan, dir, info), |
|
&uval); |
|
if (ret < 0) |
|
return ret; |
|
|
|
if (info == IIO_EV_INFO_HYSTERESIS || chan->type == IIO_VOLTAGE) |
|
*val = uval & AD7291_VALUE_MASK; |
|
|
|
else |
|
*val = sign_extend32(uval, 11); |
|
|
|
return IIO_VAL_INT; |
|
} |
|
|
|
static int ad7291_write_event_value(struct iio_dev *indio_dev, |
|
const struct iio_chan_spec *chan, |
|
enum iio_event_type type, |
|
enum iio_event_direction dir, |
|
enum iio_event_info info, |
|
int val, int val2) |
|
{ |
|
struct ad7291_chip_info *chip = iio_priv(indio_dev); |
|
|
|
if (info == IIO_EV_INFO_HYSTERESIS || chan->type == IIO_VOLTAGE) { |
|
if (val > AD7291_VALUE_MASK || val < 0) |
|
return -EINVAL; |
|
} else { |
|
if (val > 2047 || val < -2048) |
|
return -EINVAL; |
|
} |
|
|
|
return ad7291_i2c_write(chip, ad7291_threshold_reg(chan, dir, info), |
|
val); |
|
} |
|
|
|
static int ad7291_read_event_config(struct iio_dev *indio_dev, |
|
const struct iio_chan_spec *chan, |
|
enum iio_event_type type, |
|
enum iio_event_direction dir) |
|
{ |
|
struct ad7291_chip_info *chip = iio_priv(indio_dev); |
|
/* |
|
* To be enabled the channel must simply be on. If any are enabled |
|
* we are in continuous sampling mode |
|
*/ |
|
|
|
switch (chan->type) { |
|
case IIO_VOLTAGE: |
|
return !!(chip->c_mask & BIT(15 - chan->channel)); |
|
case IIO_TEMP: |
|
/* always on */ |
|
return 1; |
|
default: |
|
return -EINVAL; |
|
} |
|
|
|
} |
|
|
|
static int ad7291_write_event_config(struct iio_dev *indio_dev, |
|
const struct iio_chan_spec *chan, |
|
enum iio_event_type type, |
|
enum iio_event_direction dir, |
|
int state) |
|
{ |
|
int ret = 0; |
|
struct ad7291_chip_info *chip = iio_priv(indio_dev); |
|
unsigned int mask; |
|
u16 regval; |
|
|
|
mutex_lock(&chip->state_lock); |
|
regval = chip->command; |
|
/* |
|
* To be enabled the channel must simply be on. If any are enabled |
|
* use continuous sampling mode. |
|
* Possible to disable temp as well but that makes single read tricky. |
|
*/ |
|
|
|
mask = BIT(15 - chan->channel); |
|
|
|
switch (chan->type) { |
|
case IIO_VOLTAGE: |
|
if ((!state) && (chip->c_mask & mask)) |
|
chip->c_mask &= ~mask; |
|
else if (state && (!(chip->c_mask & mask))) |
|
chip->c_mask |= mask; |
|
else |
|
break; |
|
|
|
regval &= ~AD7291_AUTOCYCLE; |
|
regval |= chip->c_mask; |
|
if (chip->c_mask) /* Enable autocycle? */ |
|
regval |= AD7291_AUTOCYCLE; |
|
|
|
ret = ad7291_i2c_write(chip, AD7291_COMMAND, regval); |
|
if (ret < 0) |
|
goto error_ret; |
|
|
|
chip->command = regval; |
|
break; |
|
default: |
|
ret = -EINVAL; |
|
} |
|
|
|
error_ret: |
|
mutex_unlock(&chip->state_lock); |
|
return ret; |
|
} |
|
|
|
static int ad7291_read_raw(struct iio_dev *indio_dev, |
|
struct iio_chan_spec const *chan, |
|
int *val, |
|
int *val2, |
|
long mask) |
|
{ |
|
int ret; |
|
struct ad7291_chip_info *chip = iio_priv(indio_dev); |
|
u16 regval; |
|
|
|
switch (mask) { |
|
case IIO_CHAN_INFO_RAW: |
|
switch (chan->type) { |
|
case IIO_VOLTAGE: |
|
mutex_lock(&chip->state_lock); |
|
/* If in autocycle mode drop through */ |
|
if (chip->command & AD7291_AUTOCYCLE) { |
|
mutex_unlock(&chip->state_lock); |
|
return -EBUSY; |
|
} |
|
/* Enable this channel alone */ |
|
regval = chip->command & (~AD7291_VOLTAGE_MASK); |
|
regval |= BIT(15 - chan->channel); |
|
ret = ad7291_i2c_write(chip, AD7291_COMMAND, regval); |
|
if (ret < 0) { |
|
mutex_unlock(&chip->state_lock); |
|
return ret; |
|
} |
|
/* Read voltage */ |
|
ret = i2c_smbus_read_word_swapped(chip->client, |
|
AD7291_VOLTAGE); |
|
if (ret < 0) { |
|
mutex_unlock(&chip->state_lock); |
|
return ret; |
|
} |
|
*val = ret & AD7291_VALUE_MASK; |
|
mutex_unlock(&chip->state_lock); |
|
return IIO_VAL_INT; |
|
case IIO_TEMP: |
|
/* Assumes tsense bit of command register always set */ |
|
ret = i2c_smbus_read_word_swapped(chip->client, |
|
AD7291_T_SENSE); |
|
if (ret < 0) |
|
return ret; |
|
*val = sign_extend32(ret, 11); |
|
return IIO_VAL_INT; |
|
default: |
|
return -EINVAL; |
|
} |
|
case IIO_CHAN_INFO_AVERAGE_RAW: |
|
ret = i2c_smbus_read_word_swapped(chip->client, |
|
AD7291_T_AVERAGE); |
|
if (ret < 0) |
|
return ret; |
|
*val = sign_extend32(ret, 11); |
|
return IIO_VAL_INT; |
|
case IIO_CHAN_INFO_SCALE: |
|
switch (chan->type) { |
|
case IIO_VOLTAGE: |
|
if (chip->reg) { |
|
int vref; |
|
|
|
vref = regulator_get_voltage(chip->reg); |
|
if (vref < 0) |
|
return vref; |
|
*val = vref / 1000; |
|
} else { |
|
*val = 2500; |
|
} |
|
*val2 = AD7291_BITS; |
|
return IIO_VAL_FRACTIONAL_LOG2; |
|
case IIO_TEMP: |
|
/* |
|
* One LSB of the ADC corresponds to 0.25 deg C. |
|
* The temperature reading is in 12-bit twos |
|
* complement format |
|
*/ |
|
*val = 250; |
|
return IIO_VAL_INT; |
|
default: |
|
return -EINVAL; |
|
} |
|
default: |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
static const struct iio_event_spec ad7291_events[] = { |
|
{ |
|
.type = IIO_EV_TYPE_THRESH, |
|
.dir = IIO_EV_DIR_RISING, |
|
.mask_separate = BIT(IIO_EV_INFO_VALUE) | |
|
BIT(IIO_EV_INFO_ENABLE), |
|
}, { |
|
.type = IIO_EV_TYPE_THRESH, |
|
.dir = IIO_EV_DIR_FALLING, |
|
.mask_separate = BIT(IIO_EV_INFO_VALUE) | |
|
BIT(IIO_EV_INFO_ENABLE), |
|
}, { |
|
.type = IIO_EV_TYPE_THRESH, |
|
.dir = IIO_EV_DIR_EITHER, |
|
.mask_separate = BIT(IIO_EV_INFO_HYSTERESIS), |
|
}, |
|
}; |
|
|
|
#define AD7291_VOLTAGE_CHAN(_chan) \ |
|
{ \ |
|
.type = IIO_VOLTAGE, \ |
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
|
.indexed = 1, \ |
|
.channel = _chan, \ |
|
.event_spec = ad7291_events, \ |
|
.num_event_specs = ARRAY_SIZE(ad7291_events), \ |
|
} |
|
|
|
static const struct iio_chan_spec ad7291_channels[] = { |
|
AD7291_VOLTAGE_CHAN(0), |
|
AD7291_VOLTAGE_CHAN(1), |
|
AD7291_VOLTAGE_CHAN(2), |
|
AD7291_VOLTAGE_CHAN(3), |
|
AD7291_VOLTAGE_CHAN(4), |
|
AD7291_VOLTAGE_CHAN(5), |
|
AD7291_VOLTAGE_CHAN(6), |
|
AD7291_VOLTAGE_CHAN(7), |
|
{ |
|
.type = IIO_TEMP, |
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
|
BIT(IIO_CHAN_INFO_AVERAGE_RAW) | |
|
BIT(IIO_CHAN_INFO_SCALE), |
|
.indexed = 1, |
|
.channel = 0, |
|
.event_spec = ad7291_events, |
|
.num_event_specs = ARRAY_SIZE(ad7291_events), |
|
} |
|
}; |
|
|
|
static const struct iio_info ad7291_info = { |
|
.read_raw = &ad7291_read_raw, |
|
.read_event_config = &ad7291_read_event_config, |
|
.write_event_config = &ad7291_write_event_config, |
|
.read_event_value = &ad7291_read_event_value, |
|
.write_event_value = &ad7291_write_event_value, |
|
}; |
|
|
|
static int ad7291_probe(struct i2c_client *client, |
|
const struct i2c_device_id *id) |
|
{ |
|
struct ad7291_chip_info *chip; |
|
struct iio_dev *indio_dev; |
|
int ret; |
|
|
|
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip)); |
|
if (!indio_dev) |
|
return -ENOMEM; |
|
chip = iio_priv(indio_dev); |
|
|
|
mutex_init(&chip->state_lock); |
|
/* this is only used for device removal purposes */ |
|
i2c_set_clientdata(client, indio_dev); |
|
|
|
chip->client = client; |
|
|
|
chip->command = AD7291_NOISE_DELAY | |
|
AD7291_T_SENSE_MASK | /* Tsense always enabled */ |
|
AD7291_ALERT_POLARITY; /* set irq polarity low level */ |
|
|
|
chip->reg = devm_regulator_get_optional(&client->dev, "vref"); |
|
if (IS_ERR(chip->reg)) { |
|
if (PTR_ERR(chip->reg) != -ENODEV) |
|
return PTR_ERR(chip->reg); |
|
|
|
chip->reg = NULL; |
|
} |
|
|
|
if (chip->reg) { |
|
ret = regulator_enable(chip->reg); |
|
if (ret) |
|
return ret; |
|
|
|
chip->command |= AD7291_EXT_REF; |
|
} |
|
|
|
indio_dev->name = id->name; |
|
indio_dev->channels = ad7291_channels; |
|
indio_dev->num_channels = ARRAY_SIZE(ad7291_channels); |
|
|
|
indio_dev->info = &ad7291_info; |
|
indio_dev->modes = INDIO_DIRECT_MODE; |
|
|
|
ret = ad7291_i2c_write(chip, AD7291_COMMAND, AD7291_RESET); |
|
if (ret) { |
|
ret = -EIO; |
|
goto error_disable_reg; |
|
} |
|
|
|
ret = ad7291_i2c_write(chip, AD7291_COMMAND, chip->command); |
|
if (ret) { |
|
ret = -EIO; |
|
goto error_disable_reg; |
|
} |
|
|
|
if (client->irq > 0) { |
|
ret = request_threaded_irq(client->irq, |
|
NULL, |
|
&ad7291_event_handler, |
|
IRQF_TRIGGER_LOW | IRQF_ONESHOT, |
|
id->name, |
|
indio_dev); |
|
if (ret) |
|
goto error_disable_reg; |
|
} |
|
|
|
ret = iio_device_register(indio_dev); |
|
if (ret) |
|
goto error_unreg_irq; |
|
|
|
return 0; |
|
|
|
error_unreg_irq: |
|
if (client->irq) |
|
free_irq(client->irq, indio_dev); |
|
error_disable_reg: |
|
if (chip->reg) |
|
regulator_disable(chip->reg); |
|
|
|
return ret; |
|
} |
|
|
|
static int ad7291_remove(struct i2c_client *client) |
|
{ |
|
struct iio_dev *indio_dev = i2c_get_clientdata(client); |
|
struct ad7291_chip_info *chip = iio_priv(indio_dev); |
|
|
|
iio_device_unregister(indio_dev); |
|
|
|
if (client->irq) |
|
free_irq(client->irq, indio_dev); |
|
|
|
if (chip->reg) |
|
regulator_disable(chip->reg); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct i2c_device_id ad7291_id[] = { |
|
{ "ad7291", 0 }, |
|
{} |
|
}; |
|
|
|
MODULE_DEVICE_TABLE(i2c, ad7291_id); |
|
|
|
static const struct of_device_id ad7291_of_match[] = { |
|
{ .compatible = "adi,ad7291" }, |
|
{} |
|
}; |
|
MODULE_DEVICE_TABLE(of, ad7291_of_match); |
|
|
|
static struct i2c_driver ad7291_driver = { |
|
.driver = { |
|
.name = KBUILD_MODNAME, |
|
.of_match_table = ad7291_of_match, |
|
}, |
|
.probe = ad7291_probe, |
|
.remove = ad7291_remove, |
|
.id_table = ad7291_id, |
|
}; |
|
module_i2c_driver(ad7291_driver); |
|
|
|
MODULE_AUTHOR("Sonic Zhang <[email protected]>"); |
|
MODULE_DESCRIPTION("Analog Devices AD7291 ADC driver"); |
|
MODULE_LICENSE("GPL v2");
|
|
|