/*
* hp206c.c - HOPERF HP206C precision barometer and altimeter sensor
*
* Copyright (c) 2016, Intel Corporation.
*
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
*
* (7-bit I2C slave address 0x76)
*
* Datasheet:
* http://www.hoperf.com/upload/sensor/HP206C_DataSheet_EN_V2.0.pdf
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/delay.h>
#include <linux/util_macros.h>
#include <linux/acpi.h>
/* I2C commands: */
#define HP206C_CMD_SOFT_RST 0x06
#define HP206C_CMD_ADC_CVT 0x40
#define HP206C_CMD_ADC_CVT_OSR_4096 0x00
#define HP206C_CMD_ADC_CVT_OSR_2048 0x04
#define HP206C_CMD_ADC_CVT_OSR_1024 0x08
#define HP206C_CMD_ADC_CVT_OSR_512 0x0c
#define HP206C_CMD_ADC_CVT_OSR_256 0x10
#define HP206C_CMD_ADC_CVT_OSR_128 0x14
#define HP206C_CMD_ADC_CVT_CHNL_PT 0x00
#define HP206C_CMD_ADC_CVT_CHNL_T 0x02
#define HP206C_CMD_READ_P 0x30
#define HP206C_CMD_READ_T 0x32
#define HP206C_CMD_READ_REG 0x80
#define HP206C_CMD_WRITE_REG 0xc0
#define HP206C_REG_INT_EN 0x0b
#define HP206C_REG_INT_CFG 0x0c
#define HP206C_REG_INT_SRC 0x0d
#define HP206C_FLAG_DEV_RDY 0x40
#define HP206C_REG_PARA 0x0f
#define HP206C_FLAG_CMPS_EN 0x80
/* Maximum spin for DEV_RDY */
#define HP206C_MAX_DEV_RDY_WAIT_COUNT 20
#define HP206C_DEV_RDY_WAIT_US 20000
struct hp206c_data {
struct mutex mutex;
struct i2c_client *client;
int temp_osr_index;
int pres_osr_index;
};
struct hp206c_osr_setting {
u8 osr_mask;
unsigned int temp_conv_time_us;
unsigned int pres_conv_time_us;
};
/* Data from Table 5 in datasheet. */
static const struct hp206c_osr_setting hp206c_osr_settings[] = {
{ HP206C_CMD_ADC_CVT_OSR_4096, 65600, 131100 },
{ HP206C_CMD_ADC_CVT_OSR_2048, 32800, 65600 },
{ HP206C_CMD_ADC_CVT_OSR_1024, 16400, 32800 },
{ HP206C_CMD_ADC_CVT_OSR_512, 8200, 16400 },
{ HP206C_CMD_ADC_CVT_OSR_256, 4100, 8200 },
{ HP206C_CMD_ADC_CVT_OSR_128, 2100, 4100 },
};
static const int hp206c_osr_rates[] = { 4096, 2048, 1024, 512, 256, 128 };
static const char hp206c_osr_rates_str[] = "4096 2048 1024 512 256 128";
static inline int hp206c_read_reg(struct i2c_client *client, u8 reg)
{
return i2c_smbus_read_byte_data(client, HP206C_CMD_READ_REG | reg);
}
static inline int hp206c_write_reg(struct i2c_client *client, u8 reg, u8 val)
{
return i2c_smbus_write_byte_data(client,
HP206C_CMD_WRITE_REG | reg, val);
}
static int hp206c_read_20bit(struct i2c_client *client, u8 cmd)
{
int ret;
u8 values[3];
ret = i2c_smbus_read_i2c_block_data(client, cmd, 3, values);
if (ret < 0)
return ret;
if (ret != 3)
return -EIO;
return ((values[0] & 0xF) << 16) | (values[1] << 8) | (values[2]);
}
/* Spin for max 160ms until DEV_RDY is 1, or return error. */
static int hp206c_wait_dev_rdy(struct iio_dev *indio_dev)
{
int ret;
int count = 0;
struct hp206c_data *data = iio_priv(indio_dev);
struct i2c_client *client = data->client;
while (++count <= HP206C_MAX_DEV_RDY_WAIT_COUNT) {
ret = hp206c_read_reg(client, HP206C_REG_INT_SRC);
if (ret < 0) {
dev_err(&indio_dev->dev, "Failed READ_REG INT_SRC: %d\n", ret);
return ret;
}
if (ret & HP206C_FLAG_DEV_RDY)
return 0;
usleep_range(HP206C_DEV_RDY_WAIT_US, HP206C_DEV_RDY_WAIT_US * 3 / 2);
}
return -ETIMEDOUT;
}
static int hp206c_set_compensation(struct i2c_client *client, bool enabled)
{
int val;
val = hp206c_read_reg(client, HP206C_REG_PARA);
if (val < 0)
return val;
if (enabled)
val |= HP206C_FLAG_CMPS_EN;
else
val &= ~HP206C_FLAG_CMPS_EN;
return hp206c_write_reg(client, HP206C_REG_PARA, val);
}
/* Do a soft reset */
static int hp206c_soft_reset(struct iio_dev *indio_dev)
{
int ret;
struct hp206c_data *data = iio_priv(indio_dev);
struct i2c_client *client = data->client;
ret = i2c_smbus_write_byte(client, HP206C_CMD_SOFT_RST);
if (ret) {
dev_err(&client->dev, "Failed to reset device: %d\n", ret);
return ret;
}
usleep_range(400, 600);
ret = hp206c_wait_dev_rdy(indio_dev);
if (ret) {
dev_err(&client->dev, "Device not ready after soft reset: %d\n", ret);
return ret;
}
ret = hp206c_set_compensation(client, true);
if (ret)
dev_err(&client->dev, "Failed to enable compensation: %d\n", ret);
return ret;
}
static int hp206c_conv_and_read(struct iio_dev *indio_dev,
u8 conv_cmd, u8 read_cmd,
unsigned int sleep_us)
{
int ret;
struct hp206c_data *data = iio_priv(indio_dev);
struct i2c_client *client = data->client;
ret = hp206c_wait_dev_rdy(indio_dev);
if (ret < 0) {
dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
return ret;
}
ret = i2c_smbus_write_byte(client, conv_cmd);
if (ret < 0) {
dev_err(&indio_dev->dev, "Failed convert: %d\n", ret);
return ret;
}
usleep_range(sleep_us, sleep_us * 3 / 2);
ret = hp206c_wait_dev_rdy(indio_dev);
if (ret < 0) {
dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
return ret;
}
ret = hp206c_read_20bit(client, read_cmd);
if (ret < 0)
dev_err(&indio_dev->dev, "Failed read: %d\n", ret);
return ret;
}
static int hp206c_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
int ret;
struct hp206c_data *data = iio_priv(indio_dev);
const struct hp206c_osr_setting *osr_setting;
u8 conv_cmd;
mutex_lock(&data->mutex);
switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
switch (chan->type) {
case IIO_TEMP:
*val = hp206c_osr_rates[data->temp_osr_index];
ret = IIO_VAL_INT;
break;
case IIO_PRESSURE:
*val = hp206c_osr_rates[data->pres_osr_index];
ret = IIO_VAL_INT;
break;
default:
ret = -EINVAL;
}
break;
case IIO_CHAN_INFO_RAW:
switch (chan->type) {
case IIO_TEMP:
osr_setting = &hp206c_osr_settings[data->temp_osr_index];
conv_cmd = HP206C_CMD_ADC_CVT |
osr_setting->osr_mask |
HP206C_CMD_ADC_CVT_CHNL_T;
ret = hp206c_conv_and_read(indio_dev,
conv_cmd,
HP206C_CMD_READ_T,
osr_setting->temp_conv_time_us);
if (ret >= 0) {
/* 20 significant bits are provided.
* Extend sign over the rest.
*/
*val = sign_extend32(ret, 19);
ret = IIO_VAL_INT;
}
break;
case IIO_PRESSURE:
osr_setting = &hp206c_osr_settings[data->pres_osr_index];
conv_cmd = HP206C_CMD_ADC_CVT |
osr_setting->osr_mask |
HP206C_CMD_ADC_CVT_CHNL_PT;
ret = hp206c_conv_and_read(indio_dev,
conv_cmd,
HP206C_CMD_READ_P,
osr_setting->pres_conv_time_us);
if (ret >= 0) {
*val = ret;
ret = IIO_VAL_INT;
}
break;
default:
ret = -EINVAL;
}
break;
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_TEMP:
*val = 0;
*val2 = 10000;
ret = IIO_VAL_INT_PLUS_MICRO;
break;
case IIO_PRESSURE:
*val = 0;
*val2 = 1000;
ret = IIO_VAL_INT_PLUS_MICRO;
break;
default:
ret = -EINVAL;
}
break;
default:
ret = -EINVAL;
}
mutex_unlock(&data->mutex);
return ret;
}
static int hp206c_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
int ret = 0;
struct hp206c_data *data = iio_priv(indio_dev);
if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
return -EINVAL;
mutex_lock(&data->mutex);
switch (chan->type) {
case IIO_TEMP:
data->temp_osr_index = find_closest_descending(val,
hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
break;
case IIO_PRESSURE:
data->pres_osr_index = find_closest_descending(val,
hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
break;
default:
ret = -EINVAL;
}
mutex_unlock(&data->mutex);
return ret;
}
static const struct iio_chan_spec hp206c_channels[] = {
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
},
{
.type = IIO_PRESSURE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
}
};
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(hp206c_osr_rates_str);
static struct attribute *hp206c_attributes[] = {
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
NULL,
};
static const struct attribute_group hp206c_attribute_group = {
.attrs = hp206c_attributes,
};
static const struct iio_info hp206c_info = {
.attrs = &hp206c_attribute_group,
.read_raw = hp206c_read_raw,
.write_raw = hp206c_write_raw,
.driver_module = THIS_MODULE,
};
static int hp206c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct iio_dev *indio_dev;
struct hp206c_data *data;
int ret;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
dev_err(&client->dev, "Adapter does not support "
"all required i2c functionality\n");
return -ENODEV;
}
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
data->client = client;
mutex_init(&data->mutex);
indio_dev->info = &hp206c_info;
indio_dev->name = id->name;
indio_dev->dev.parent = &client->dev;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = hp206c_channels;
indio_dev->num_channels = ARRAY_SIZE(hp206c_channels);
i2c_set_clientdata(client, indio_dev);
/* Do a soft reset on probe */
ret = hp206c_soft_reset(indio_dev);
if (ret) {
dev_err(&client->dev, "Failed to reset on startup: %d\n", ret);
return -ENODEV;
}
return devm_iio_device_register(&client->dev, indio_dev);
}
static const struct i2c_device_id hp206c_id[] = {
{"hp206c"},
{}
};
MODULE_DEVICE_TABLE(i2c, hp206c_id);
#ifdef CONFIG_ACPI
static const struct acpi_device_id hp206c_acpi_match[] = {
{"HOP206C", 0},
{ },
};
MODULE_DEVICE_TABLE(acpi, hp206c_acpi_match);
#endif
static struct i2c_driver hp206c_driver = {
.probe = hp206c_probe,
.id_table = hp206c_id,
.driver = {
.name = "hp206c",
.acpi_match_table = ACPI_PTR(hp206c_acpi_match),
},
};
module_i2c_driver(hp206c_driver);
MODULE_DESCRIPTION("HOPERF HP206C precision barometer and altimeter sensor");
MODULE_AUTHOR("Leonard Crestez <leonard.crestez@intel.com>");
MODULE_LICENSE("GPL v2");