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