// SPDX-License-Identifier: GPL-2.0+
/*
* AD7150 capacitive sensor driver supporting AD7150/1/6
*
* Copyright 2010-2011 Analog Devices Inc.
* Copyright 2021 Jonathan Cameron <[email protected]>
*/
#include <linux/bitfield.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#define AD7150_STATUS_REG 0
#define AD7150_STATUS_OUT1 BIT(3)
#define AD7150_STATUS_OUT2 BIT(5)
#define AD7150_CH1_DATA_HIGH_REG 1
#define AD7150_CH2_DATA_HIGH_REG 3
#define AD7150_CH1_AVG_HIGH_REG 5
#define AD7150_CH2_AVG_HIGH_REG 7
#define AD7150_CH1_SENSITIVITY_REG 9
#define AD7150_CH1_THR_HOLD_H_REG 9
#define AD7150_CH1_TIMEOUT_REG 10
#define AD7150_CH_TIMEOUT_RECEDING GENMASK(3, 0)
#define AD7150_CH_TIMEOUT_APPROACHING GENMASK(7, 4)
#define AD7150_CH1_SETUP_REG 11
#define AD7150_CH2_SENSITIVITY_REG 12
#define AD7150_CH2_THR_HOLD_H_REG 12
#define AD7150_CH2_TIMEOUT_REG 13
#define AD7150_CH2_SETUP_REG 14
#define AD7150_CFG_REG 15
#define AD7150_CFG_FIX BIT(7)
#define AD7150_CFG_THRESHTYPE_MSK GENMASK(6, 5)
#define AD7150_CFG_TT_NEG 0x0
#define AD7150_CFG_TT_POS 0x1
#define AD7150_CFG_TT_IN_WINDOW 0x2
#define AD7150_CFG_TT_OUT_WINDOW 0x3
#define AD7150_PD_TIMER_REG 16
#define AD7150_CH1_CAPDAC_REG 17
#define AD7150_CH2_CAPDAC_REG 18
#define AD7150_SN3_REG 19
#define AD7150_SN2_REG 20
#define AD7150_SN1_REG 21
#define AD7150_SN0_REG 22
#define AD7150_ID_REG 23
enum {
AD7150,
AD7151,
};
/**
* struct ad7150_chip_info - instance specific chip data
* @client: i2c client for this device
* @threshold: thresholds for simple capacitance value events
* @thresh_sensitivity: threshold for simple capacitance offset
* from 'average' value.
* @thresh_timeout: a timeout, in samples from the moment an
* adaptive threshold event occurs to when the average
* value jumps to current value. Note made up of two fields,
* 3:0 are for timeout receding - applies if below lower threshold
* 7:4 are for timeout approaching - applies if above upper threshold
* @state_lock: ensure consistent state of this structure wrt the
* hardware.
* @interrupts: one or two interrupt numbers depending on device type.
* @int_enabled: is a given interrupt currently enabled.
* @type: threshold type
* @dir: threshold direction
*/
struct ad7150_chip_info {
struct i2c_client *client;
u16 threshold[2][2];
u8 thresh_sensitivity[2][2];
u8 thresh_timeout[2][2];
struct mutex state_lock;
int interrupts[2];
bool int_enabled[2];
enum iio_event_type type;
enum iio_event_direction dir;
};
static const u8 ad7150_addresses[][6] = {
{ AD7150_CH1_DATA_HIGH_REG, AD7150_CH1_AVG_HIGH_REG,
AD7150_CH1_SETUP_REG, AD7150_CH1_THR_HOLD_H_REG,
AD7150_CH1_SENSITIVITY_REG, AD7150_CH1_TIMEOUT_REG },
{ AD7150_CH2_DATA_HIGH_REG, AD7150_CH2_AVG_HIGH_REG,
AD7150_CH2_SETUP_REG, AD7150_CH2_THR_HOLD_H_REG,
AD7150_CH2_SENSITIVITY_REG, AD7150_CH2_TIMEOUT_REG },
};
static int ad7150_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
struct ad7150_chip_info *chip = iio_priv(indio_dev);
int channel = chan->channel;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = i2c_smbus_read_word_swapped(chip->client,
ad7150_addresses[channel][0]);
if (ret < 0)
return ret;
*val = ret >> 4;
return IIO_VAL_INT;
case IIO_CHAN_INFO_AVERAGE_RAW:
ret = i2c_smbus_read_word_swapped(chip->client,
ad7150_addresses[channel][1]);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
/*
* Base units for capacitance are nano farads and the value
* calculated from the datasheet formula is in picofarad
* so multiply by 1000
*/
*val = 1000;
*val2 = 40944 >> 4; /* To match shift in _RAW */
return IIO_VAL_FRACTIONAL;
case IIO_CHAN_INFO_OFFSET:
*val = -(12288 >> 4); /* To match shift in _RAW */
return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
/* Strangely same for both 1 and 2 chan parts */
*val = 100;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad7150_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 ad7150_chip_info *chip = iio_priv(indio_dev);
u8 threshtype;
bool thrfixed;
int ret;
ret = i2c_smbus_read_byte_data(chip->client, AD7150_CFG_REG);
if (ret < 0)
return ret;
threshtype = FIELD_GET(AD7150_CFG_THRESHTYPE_MSK, ret);
/*check if threshold mode is fixed or adaptive*/
thrfixed = FIELD_GET(AD7150_CFG_FIX, ret);
switch (type) {
case IIO_EV_TYPE_THRESH_ADAPTIVE:
if (dir == IIO_EV_DIR_RISING)
return !thrfixed && (threshtype == AD7150_CFG_TT_POS);
return !thrfixed && (threshtype == AD7150_CFG_TT_NEG);
case IIO_EV_TYPE_THRESH:
if (dir == IIO_EV_DIR_RISING)
return thrfixed && (threshtype == AD7150_CFG_TT_POS);
return thrfixed && (threshtype == AD7150_CFG_TT_NEG);
default:
break;
}
return -EINVAL;
}
/* state_lock should be held to ensure consistent state */
static int ad7150_write_event_params(struct iio_dev *indio_dev,
unsigned int chan,
enum iio_event_type type,
enum iio_event_direction dir)
{
struct ad7150_chip_info *chip = iio_priv(indio_dev);
int rising = (dir == IIO_EV_DIR_RISING);
/* Only update value live, if parameter is in use */
if ((type != chip->type) || (dir != chip->dir))
return 0;
switch (type) {
/* Note completely different from the adaptive versions */
case IIO_EV_TYPE_THRESH: {
u16 value = chip->threshold[rising][chan];
return i2c_smbus_write_word_swapped(chip->client,
ad7150_addresses[chan][3],
value);
}
case IIO_EV_TYPE_THRESH_ADAPTIVE: {
int ret;
u8 sens, timeout;
sens = chip->thresh_sensitivity[rising][chan];
ret = i2c_smbus_write_byte_data(chip->client,
ad7150_addresses[chan][4],
sens);
if (ret)
return ret;
/*
* Single timeout register contains timeouts for both
* directions.
*/
timeout = FIELD_PREP(AD7150_CH_TIMEOUT_APPROACHING,
chip->thresh_timeout[1][chan]);
timeout |= FIELD_PREP(AD7150_CH_TIMEOUT_RECEDING,
chip->thresh_timeout[0][chan]);
return i2c_smbus_write_byte_data(chip->client,
ad7150_addresses[chan][5],
timeout);
}
default:
return -EINVAL;
}
}
static int ad7150_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)
{
struct ad7150_chip_info *chip = iio_priv(indio_dev);
int ret = 0;
/*
* There is only a single shared control and no on chip
* interrupt disables for the two interrupt lines.
* So, enabling will switch the events configured to enable
* whatever was most recently requested and if necessary enable_irq()
* the interrupt and any disable will disable_irq() for that
* channels interrupt.
*/
if (!state) {
if ((chip->int_enabled[chan->channel]) &&
(type == chip->type) && (dir == chip->dir)) {
disable_irq(chip->interrupts[chan->channel]);
chip->int_enabled[chan->channel] = false;
}
return 0;
}
mutex_lock(&chip->state_lock);
if ((type != chip->type) || (dir != chip->dir)) {
int rising = (dir == IIO_EV_DIR_RISING);
u8 thresh_type, cfg, fixed;
/*
* Need to temporarily disable both interrupts if
* enabled - this is to avoid races around changing
* config and thresholds.
* Note enable/disable_irq() are reference counted so
* no need to check if already enabled.
*/
disable_irq(chip->interrupts[0]);
disable_irq(chip->interrupts[1]);
ret = i2c_smbus_read_byte_data(chip->client, AD7150_CFG_REG);
if (ret < 0)
goto error_ret;
cfg = ret & ~(AD7150_CFG_THRESHTYPE_MSK | AD7150_CFG_FIX);
if (type == IIO_EV_TYPE_THRESH_ADAPTIVE)
fixed = 0;
else
fixed = 1;
if (rising)
thresh_type = AD7150_CFG_TT_POS;
else
thresh_type = AD7150_CFG_TT_NEG;
cfg |= FIELD_PREP(AD7150_CFG_FIX, fixed) |
FIELD_PREP(AD7150_CFG_THRESHTYPE_MSK, thresh_type);
ret = i2c_smbus_write_byte_data(chip->client, AD7150_CFG_REG,
cfg);
if (ret < 0)
goto error_ret;
/*
* There is a potential race condition here, but not easy
* to close given we can't disable the interrupt at the
* chip side of things. Rely on the status bit.
*/
chip->type = type;
chip->dir = dir;
/* update control attributes */
ret = ad7150_write_event_params(indio_dev, chan->channel, type,
dir);
if (ret)
goto error_ret;
/* reenable any irq's we disabled whilst changing mode */
enable_irq(chip->interrupts[0]);
enable_irq(chip->interrupts[1]);
}
if (!chip->int_enabled[chan->channel]) {
enable_irq(chip->interrupts[chan->channel]);
chip->int_enabled[chan->channel] = true;
}
error_ret:
mutex_unlock(&chip->state_lock);
return ret;
}
static int ad7150_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 ad7150_chip_info *chip = iio_priv(indio_dev);
int rising = (dir == IIO_EV_DIR_RISING);
/* Complex register sharing going on here */
switch (info) {
case IIO_EV_INFO_VALUE:
switch (type) {
case IIO_EV_TYPE_THRESH_ADAPTIVE:
*val = chip->thresh_sensitivity[rising][chan->channel];
return IIO_VAL_INT;
case IIO_EV_TYPE_THRESH:
*val = chip->threshold[rising][chan->channel];
return IIO_VAL_INT;
default:
return -EINVAL;
}
case IIO_EV_INFO_TIMEOUT:
*val = 0;
*val2 = chip->thresh_timeout[rising][chan->channel] * 10000;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static int ad7150_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)
{
int ret;
struct ad7150_chip_info *chip = iio_priv(indio_dev);
int rising = (dir == IIO_EV_DIR_RISING);
mutex_lock(&chip->state_lock);
switch (info) {
case IIO_EV_INFO_VALUE:
switch (type) {
case IIO_EV_TYPE_THRESH_ADAPTIVE:
chip->thresh_sensitivity[rising][chan->channel] = val;
break;
case IIO_EV_TYPE_THRESH:
chip->threshold[rising][chan->channel] = val;
break;
default:
ret = -EINVAL;
goto error_ret;
}
break;
case IIO_EV_INFO_TIMEOUT: {
/*
* Raw timeout is in cycles of 10 msecs as long as both
* channels are enabled.
* In terms of INT_PLUS_MICRO, that is in units of 10,000
*/
int timeout = val2 / 10000;
if (val != 0 || timeout < 0 || timeout > 15 || val2 % 10000) {
ret = -EINVAL;
goto error_ret;
}
chip->thresh_timeout[rising][chan->channel] = timeout;
break;
}
default:
ret = -EINVAL;
goto error_ret;
}
/* write back if active */
ret = ad7150_write_event_params(indio_dev, chan->channel, type, dir);
error_ret:
mutex_unlock(&chip->state_lock);
return ret;
}
static const struct iio_event_spec ad7150_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_ADAPTIVE,
.dir = IIO_EV_DIR_RISING,
.mask_separate = BIT(IIO_EV_INFO_VALUE) |
BIT(IIO_EV_INFO_ENABLE) |
BIT(IIO_EV_INFO_TIMEOUT),
}, {
.type = IIO_EV_TYPE_THRESH_ADAPTIVE,
.dir = IIO_EV_DIR_FALLING,
.mask_separate = BIT(IIO_EV_INFO_VALUE) |
BIT(IIO_EV_INFO_ENABLE) |
BIT(IIO_EV_INFO_TIMEOUT),
},
};
#define AD7150_CAPACITANCE_CHAN(_chan) { \
.type = IIO_CAPACITANCE, \
.indexed = 1, \
.channel = _chan, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_AVERAGE_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET), \
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
.event_spec = ad7150_events, \
.num_event_specs = ARRAY_SIZE(ad7150_events), \
}
#define AD7150_CAPACITANCE_CHAN_NO_IRQ(_chan) { \
.type = IIO_CAPACITANCE, \
.indexed = 1, \
.channel = _chan, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_AVERAGE_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET), \
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
}
static const struct iio_chan_spec ad7150_channels[] = {
AD7150_CAPACITANCE_CHAN(0),
AD7150_CAPACITANCE_CHAN(1),
};
static const struct iio_chan_spec ad7150_channels_no_irq[] = {
AD7150_CAPACITANCE_CHAN_NO_IRQ(0),
AD7150_CAPACITANCE_CHAN_NO_IRQ(1),
};
static const struct iio_chan_spec ad7151_channels[] = {
AD7150_CAPACITANCE_CHAN(0),
};
static const struct iio_chan_spec ad7151_channels_no_irq[] = {
AD7150_CAPACITANCE_CHAN_NO_IRQ(0),
};
static irqreturn_t __ad7150_event_handler(void *private, u8 status_mask,
int channel)
{
struct iio_dev *indio_dev = private;
struct ad7150_chip_info *chip = iio_priv(indio_dev);
s64 timestamp = iio_get_time_ns(indio_dev);
int int_status;
int_status = i2c_smbus_read_byte_data(chip->client, AD7150_STATUS_REG);
if (int_status < 0)
return IRQ_HANDLED;
if (!(int_status & status_mask))
return IRQ_HANDLED;
iio_push_event(indio_dev,
IIO_UNMOD_EVENT_CODE(IIO_CAPACITANCE, channel,
chip->type, chip->dir),
timestamp);
return IRQ_HANDLED;
}
static irqreturn_t ad7150_event_handler_ch1(int irq, void *private)
{
return __ad7150_event_handler(private, AD7150_STATUS_OUT1, 0);
}
static irqreturn_t ad7150_event_handler_ch2(int irq, void *private)
{
return __ad7150_event_handler(private, AD7150_STATUS_OUT2, 1);
}
static IIO_CONST_ATTR(in_capacitance_thresh_adaptive_timeout_available,
"[0 0.01 0.15]");
static struct attribute *ad7150_event_attributes[] = {
&iio_const_attr_in_capacitance_thresh_adaptive_timeout_available
.dev_attr.attr,
NULL,
};
static const struct attribute_group ad7150_event_attribute_group = {
.attrs = ad7150_event_attributes,
.name = "events",
};
static const struct iio_info ad7150_info = {
.event_attrs = &ad7150_event_attribute_group,
.read_raw = &ad7150_read_raw,
.read_event_config = &ad7150_read_event_config,
.write_event_config = &ad7150_write_event_config,
.read_event_value = &ad7150_read_event_value,
.write_event_value = &ad7150_write_event_value,
};
static const struct iio_info ad7150_info_no_irq = {
.read_raw = &ad7150_read_raw,
};
static int ad7150_probe(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
struct ad7150_chip_info *chip;
struct iio_dev *indio_dev;
bool use_irq = true;
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);
chip->client = client;
indio_dev->name = id->name;
indio_dev->modes = INDIO_DIRECT_MODE;
ret = devm_regulator_get_enable(&client->dev, "vdd");
if (ret)
return ret;
chip->interrupts[0] = fwnode_irq_get(dev_fwnode(&client->dev), 0);
if (chip->interrupts[0] < 0)
use_irq = false;
else if (id->driver_data == AD7150) {
chip->interrupts[1] = fwnode_irq_get(dev_fwnode(&client->dev), 1);
if (chip->interrupts[1] < 0)
use_irq = false;
}
if (use_irq) {
irq_set_status_flags(chip->interrupts[0], IRQ_NOAUTOEN);
ret = devm_request_threaded_irq(&client->dev,
chip->interrupts[0],
NULL,
&ad7150_event_handler_ch1,
IRQF_TRIGGER_RISING |
IRQF_ONESHOT,
"ad7150_irq1",
indio_dev);
if (ret)
return ret;
indio_dev->info = &ad7150_info;
switch (id->driver_data) {
case AD7150:
indio_dev->channels = ad7150_channels;
indio_dev->num_channels = ARRAY_SIZE(ad7150_channels);
irq_set_status_flags(chip->interrupts[1], IRQ_NOAUTOEN);
ret = devm_request_threaded_irq(&client->dev,
chip->interrupts[1],
NULL,
&ad7150_event_handler_ch2,
IRQF_TRIGGER_RISING |
IRQF_ONESHOT,
"ad7150_irq2",
indio_dev);
if (ret)
return ret;
break;
case AD7151:
indio_dev->channels = ad7151_channels;
indio_dev->num_channels = ARRAY_SIZE(ad7151_channels);
break;
default:
return -EINVAL;
}
} else {
indio_dev->info = &ad7150_info_no_irq;
switch (id->driver_data) {
case AD7150:
indio_dev->channels = ad7150_channels_no_irq;
indio_dev->num_channels =
ARRAY_SIZE(ad7150_channels_no_irq);
break;
case AD7151:
indio_dev->channels = ad7151_channels_no_irq;
indio_dev->num_channels =
ARRAY_SIZE(ad7151_channels_no_irq);
break;
default:
return -EINVAL;
}
}
return devm_iio_device_register(indio_dev->dev.parent, indio_dev);
}
static const struct i2c_device_id ad7150_id[] = {
{ "ad7150", AD7150 },
{ "ad7151", AD7151 },
{ "ad7156", AD7150 },
{}
};
MODULE_DEVICE_TABLE(i2c, ad7150_id);
static const struct of_device_id ad7150_of_match[] = {
{ "adi,ad7150" },
{ "adi,ad7151" },
{ "adi,ad7156" },
{}
};
static struct i2c_driver ad7150_driver = {
.driver = {
.name = "ad7150",
.of_match_table = ad7150_of_match,
},
.probe = ad7150_probe,
.id_table = ad7150_id,
};
module_i2c_driver(ad7150_driver);
MODULE_AUTHOR("Barry Song <[email protected]>");
MODULE_DESCRIPTION("Analog Devices AD7150/1/6 capacitive sensor driver");
MODULE_LICENSE("GPL v2");
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