/*
* AD7152 capacitive sensor driver supporting AD7152/3
*
* Copyright 2010-2011a Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
/*
* TODO: Check compliance of calibbias with abi (units)
*/
/*
* AD7152 registers definition
*/
#define AD7152_REG_STATUS 0
#define AD7152_REG_CH1_DATA_HIGH 1
#define AD7152_REG_CH2_DATA_HIGH 3
#define AD7152_REG_CH1_OFFS_HIGH 5
#define AD7152_REG_CH2_OFFS_HIGH 7
#define AD7152_REG_CH1_GAIN_HIGH 9
#define AD7152_REG_CH1_SETUP 11
#define AD7152_REG_CH2_GAIN_HIGH 12
#define AD7152_REG_CH2_SETUP 14
#define AD7152_REG_CFG 15
#define AD7152_REG_RESEVERD 16
#define AD7152_REG_CAPDAC_POS 17
#define AD7152_REG_CAPDAC_NEG 18
#define AD7152_REG_CFG2 26
/* Status Register Bit Designations (AD7152_REG_STATUS) */
#define AD7152_STATUS_RDY1 (1 << 0)
#define AD7152_STATUS_RDY2 (1 << 1)
#define AD7152_STATUS_C1C2 (1 << 2)
#define AD7152_STATUS_PWDN (1 << 7)
/* Setup Register Bit Designations (AD7152_REG_CHx_SETUP) */
#define AD7152_SETUP_CAPDIFF (1 << 5)
#define AD7152_SETUP_RANGE_2pF (0 << 6)
#define AD7152_SETUP_RANGE_0_5pF (1 << 6)
#define AD7152_SETUP_RANGE_1pF (2 << 6)
#define AD7152_SETUP_RANGE_4pF (3 << 6)
#define AD7152_SETUP_RANGE(x) ((x) << 6)
/* Config Register Bit Designations (AD7152_REG_CFG) */
#define AD7152_CONF_CH2EN (1 << 3)
#define AD7152_CONF_CH1EN (1 << 4)
#define AD7152_CONF_MODE_IDLE (0 << 0)
#define AD7152_CONF_MODE_CONT_CONV (1 << 0)
#define AD7152_CONF_MODE_SINGLE_CONV (2 << 0)
#define AD7152_CONF_MODE_OFFS_CAL (5 << 0)
#define AD7152_CONF_MODE_GAIN_CAL (6 << 0)
/* Capdac Register Bit Designations (AD7152_REG_CAPDAC_XXX) */
#define AD7152_CAPDAC_DACEN (1 << 7)
#define AD7152_CAPDAC_DACP(x) ((x) & 0x1F)
/* CFG2 Register Bit Designations (AD7152_REG_CFG2) */
#define AD7152_CFG2_OSR(x) (((x) & 0x3) << 4)
enum {
AD7152_DATA,
AD7152_OFFS,
AD7152_GAIN,
AD7152_SETUP
};
/*
* struct ad7152_chip_info - chip specifc information
*/
struct ad7152_chip_info {
struct i2c_client *client;
/*
* Capacitive channel digital filter setup;
* conversion time/update rate setup per channel
*/
u8 filter_rate_setup;
u8 setup[2];
};
static inline ssize_t ad7152_start_calib(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len,
u8 regval)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct ad7152_chip_info *chip = iio_priv(indio_dev);
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
bool doit;
int ret, timeout = 10;
ret = strtobool(buf, &doit);
if (ret < 0)
return ret;
if (!doit)
return 0;
if (this_attr->address == 0)
regval |= AD7152_CONF_CH1EN;
else
regval |= AD7152_CONF_CH2EN;
mutex_lock(&indio_dev->mlock);
ret = i2c_smbus_write_byte_data(chip->client, AD7152_REG_CFG, regval);
if (ret < 0) {
mutex_unlock(&indio_dev->mlock);
return ret;
}
do {
mdelay(20);
ret = i2c_smbus_read_byte_data(chip->client, AD7152_REG_CFG);
if (ret < 0) {
mutex_unlock(&indio_dev->mlock);
return ret;
}
} while ((ret == regval) && timeout--);
mutex_unlock(&indio_dev->mlock);
return len;
}
static ssize_t ad7152_start_offset_calib(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
return ad7152_start_calib(dev, attr, buf, len,
AD7152_CONF_MODE_OFFS_CAL);
}
static ssize_t ad7152_start_gain_calib(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
return ad7152_start_calib(dev, attr, buf, len,
AD7152_CONF_MODE_GAIN_CAL);
}
static IIO_DEVICE_ATTR(in_capacitance0_calibbias_calibration,
S_IWUSR, NULL, ad7152_start_offset_calib, 0);
static IIO_DEVICE_ATTR(in_capacitance1_calibbias_calibration,
S_IWUSR, NULL, ad7152_start_offset_calib, 1);
static IIO_DEVICE_ATTR(in_capacitance0_calibscale_calibration,
S_IWUSR, NULL, ad7152_start_gain_calib, 0);
static IIO_DEVICE_ATTR(in_capacitance1_calibscale_calibration,
S_IWUSR, NULL, ad7152_start_gain_calib, 1);
/* Values are Update Rate (Hz), Conversion Time (ms) + 1*/
static const unsigned char ad7152_filter_rate_table[][2] = {
{200, 5 + 1}, {50, 20 + 1}, {20, 50 + 1}, {17, 60 + 1},
};
static ssize_t ad7152_show_filter_rate_setup(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct ad7152_chip_info *chip = iio_priv(indio_dev);
return sprintf(buf, "%d\n",
ad7152_filter_rate_table[chip->filter_rate_setup][0]);
}
static ssize_t ad7152_store_filter_rate_setup(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct ad7152_chip_info *chip = iio_priv(indio_dev);
u8 data;
int ret, i;
ret = kstrtou8(buf, 10, &data);
if (ret < 0)
return ret;
for (i = 0; i < ARRAY_SIZE(ad7152_filter_rate_table); i++)
if (data >= ad7152_filter_rate_table[i][0])
break;
if (i >= ARRAY_SIZE(ad7152_filter_rate_table))
i = ARRAY_SIZE(ad7152_filter_rate_table) - 1;
mutex_lock(&indio_dev->mlock);
ret = i2c_smbus_write_byte_data(chip->client,
AD7152_REG_CFG2, AD7152_CFG2_OSR(i));
if (ret < 0) {
mutex_unlock(&indio_dev->mlock);
return ret;
}
chip->filter_rate_setup = i;
mutex_unlock(&indio_dev->mlock);
return len;
}
static IIO_DEV_ATTR_SAMP_FREQ(S_IRUGO | S_IWUSR,
ad7152_show_filter_rate_setup,
ad7152_store_filter_rate_setup);
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("200 50 20 17");
static IIO_CONST_ATTR(in_capacitance_scale_available,
"0.000061050 0.000030525 0.000015263 0.000007631");
static struct attribute *ad7152_attributes[] = {
&iio_dev_attr_sampling_frequency.dev_attr.attr,
&iio_dev_attr_in_capacitance0_calibbias_calibration.dev_attr.attr,
&iio_dev_attr_in_capacitance1_calibbias_calibration.dev_attr.attr,
&iio_dev_attr_in_capacitance0_calibscale_calibration.dev_attr.attr,
&iio_dev_attr_in_capacitance1_calibscale_calibration.dev_attr.attr,
&iio_const_attr_in_capacitance_scale_available.dev_attr.attr,
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
NULL,
};
static const struct attribute_group ad7152_attribute_group = {
.attrs = ad7152_attributes,
};
static const u8 ad7152_addresses[][4] = {
{ AD7152_REG_CH1_DATA_HIGH, AD7152_REG_CH1_OFFS_HIGH,
AD7152_REG_CH1_GAIN_HIGH, AD7152_REG_CH1_SETUP },
{ AD7152_REG_CH2_DATA_HIGH, AD7152_REG_CH2_OFFS_HIGH,
AD7152_REG_CH2_GAIN_HIGH, AD7152_REG_CH2_SETUP },
};
/* Values are nano relative to pf base. */
static const int ad7152_scale_table[] = {
30525, 7631, 15263, 61050
};
static int ad7152_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad7152_chip_info *chip = iio_priv(indio_dev);
int ret, i;
mutex_lock(&indio_dev->mlock);
switch (mask) {
case IIO_CHAN_INFO_CALIBSCALE:
if (val != 1) {
ret = -EINVAL;
goto out;
}
val = (val2 * 1024) / 15625;
ret = i2c_smbus_write_word_data(chip->client,
ad7152_addresses[chan->channel][AD7152_GAIN],
swab16(val));
if (ret < 0)
goto out;
ret = 0;
break;
case IIO_CHAN_INFO_CALIBBIAS:
if ((val < 0) | (val > 0xFFFF)) {
ret = -EINVAL;
goto out;
}
ret = i2c_smbus_write_word_data(chip->client,
ad7152_addresses[chan->channel][AD7152_OFFS],
swab16(val));
if (ret < 0)
goto out;
ret = 0;
break;
case IIO_CHAN_INFO_SCALE:
if (val != 0) {
ret = -EINVAL;
goto out;
}
for (i = 0; i < ARRAY_SIZE(ad7152_scale_table); i++)
if (val2 == ad7152_scale_table[i])
break;
chip->setup[chan->channel] &= ~AD7152_SETUP_RANGE_4pF;
chip->setup[chan->channel] |= AD7152_SETUP_RANGE(i);
ret = i2c_smbus_write_byte_data(chip->client,
ad7152_addresses[chan->channel][AD7152_SETUP],
chip->setup[chan->channel]);
if (ret < 0)
goto out;
ret = 0;
break;
default:
ret = -EINVAL;
}
out:
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad7152_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2,
long mask)
{
struct ad7152_chip_info *chip = iio_priv(indio_dev);
int ret;
u8 regval = 0;
mutex_lock(&indio_dev->mlock);
switch (mask) {
case IIO_CHAN_INFO_RAW:
/* First set whether in differential mode */
regval = chip->setup[chan->channel];
if (chan->differential)
chip->setup[chan->channel] |= AD7152_SETUP_CAPDIFF;
else
chip->setup[chan->channel] &= ~AD7152_SETUP_CAPDIFF;
if (regval != chip->setup[chan->channel]) {
ret = i2c_smbus_write_byte_data(chip->client,
ad7152_addresses[chan->channel][AD7152_SETUP],
chip->setup[chan->channel]);
if (ret < 0)
goto out;
}
/* Make sure the channel is enabled */
if (chan->channel == 0)
regval = AD7152_CONF_CH1EN;
else
regval = AD7152_CONF_CH2EN;
/* Trigger a single read */
regval |= AD7152_CONF_MODE_SINGLE_CONV;
ret = i2c_smbus_write_byte_data(chip->client, AD7152_REG_CFG,
regval);
if (ret < 0)
goto out;
msleep(ad7152_filter_rate_table[chip->filter_rate_setup][1]);
/* Now read the actual register */
ret = i2c_smbus_read_word_data(chip->client,
ad7152_addresses[chan->channel][AD7152_DATA]);
if (ret < 0)
goto out;
*val = swab16(ret);
if (chan->differential)
*val -= 0x8000;
ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_CALIBSCALE:
ret = i2c_smbus_read_word_data(chip->client,
ad7152_addresses[chan->channel][AD7152_GAIN]);
if (ret < 0)
goto out;
/* 1 + gain_val / 2^16 */
*val = 1;
*val2 = (15625 * swab16(ret)) / 1024;
ret = IIO_VAL_INT_PLUS_MICRO;
break;
case IIO_CHAN_INFO_CALIBBIAS:
ret = i2c_smbus_read_word_data(chip->client,
ad7152_addresses[chan->channel][AD7152_OFFS]);
if (ret < 0)
goto out;
*val = swab16(ret);
ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_SCALE:
ret = i2c_smbus_read_byte_data(chip->client,
ad7152_addresses[chan->channel][AD7152_SETUP]);
if (ret < 0)
goto out;
*val = 0;
*val2 = ad7152_scale_table[ret >> 6];
ret = IIO_VAL_INT_PLUS_NANO;
break;
default:
ret = -EINVAL;
}
out:
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int ad7152_write_raw_get_fmt(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
long mask)
{
switch (mask) {
case IIO_CHAN_INFO_SCALE:
return IIO_VAL_INT_PLUS_NANO;
default:
return IIO_VAL_INT_PLUS_MICRO;
}
}
static const struct iio_info ad7152_info = {
.attrs = &ad7152_attribute_group,
.read_raw = &ad7152_read_raw,
.write_raw = &ad7152_write_raw,
.write_raw_get_fmt = &ad7152_write_raw_get_fmt,
.driver_module = THIS_MODULE,
};
static const struct iio_chan_spec ad7152_channels[] = {
{
.type = IIO_CAPACITANCE,
.indexed = 1,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_CALIBBIAS) |
BIT(IIO_CHAN_INFO_SCALE),
}, {
.type = IIO_CAPACITANCE,
.differential = 1,
.indexed = 1,
.channel = 0,
.channel2 = 2,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_CALIBBIAS) |
BIT(IIO_CHAN_INFO_SCALE),
}, {
.type = IIO_CAPACITANCE,
.indexed = 1,
.channel = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_CALIBBIAS) |
BIT(IIO_CHAN_INFO_SCALE),
}, {
.type = IIO_CAPACITANCE,
.differential = 1,
.indexed = 1,
.channel = 1,
.channel2 = 3,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_CALIBBIAS) |
BIT(IIO_CHAN_INFO_SCALE),
}
};
/*
* device probe and remove
*/
static int ad7152_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret = 0;
struct ad7152_chip_info *chip;
struct iio_dev *indio_dev;
indio_dev = iio_device_alloc(sizeof(*chip));
if (indio_dev == NULL) {
ret = -ENOMEM;
goto error_ret;
}
chip = iio_priv(indio_dev);
/* this is only used for device removal purposes */
i2c_set_clientdata(client, indio_dev);
chip->client = client;
/* Establish that the iio_dev is a child of the i2c device */
indio_dev->name = id->name;
indio_dev->dev.parent = &client->dev;
indio_dev->info = &ad7152_info;
indio_dev->channels = ad7152_channels;
if (id->driver_data == 0)
indio_dev->num_channels = ARRAY_SIZE(ad7152_channels);
else
indio_dev->num_channels = 2;
indio_dev->num_channels = ARRAY_SIZE(ad7152_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
ret = iio_device_register(indio_dev);
if (ret)
goto error_free_dev;
dev_err(&client->dev, "%s capacitive sensor registered\n", id->name);
return 0;
error_free_dev:
iio_device_free(indio_dev);
error_ret:
return ret;
}
static int ad7152_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
iio_device_free(indio_dev);
return 0;
}
static const struct i2c_device_id ad7152_id[] = {
{ "ad7152", 0 },
{ "ad7153", 1 },
{}
};
MODULE_DEVICE_TABLE(i2c, ad7152_id);
static struct i2c_driver ad7152_driver = {
.driver = {
.name = KBUILD_MODNAME,
},
.probe = ad7152_probe,
.remove = ad7152_remove,
.id_table = ad7152_id,
};
module_i2c_driver(ad7152_driver);
MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_DESCRIPTION("Analog Devices AD7152/3 capacitive sensor driver");
MODULE_LICENSE("GPL v2");