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// 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>
#include <linux/platform_data/ad7291.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
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