misc: clean up bmp085 driver
This patch includes various cleaning of the bmp085 driver including: - Whitespaces and alignment fixes - Minor typos - Consistency fixes Reviewed-by: Stefan Nilsson <stefan.nilsson@unixphere.com> Signed-off-by: Eric Andersson <eric.andersson@unixphere.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric Andersson
Greg Kroah-Hartman
parent
0ed0d579cb
commit
e939ca0a63
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@ -1,62 +1,63 @@
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/* Copyright (c) 2010 Christoph Mair <christoph.mair@gmail.com>
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This driver supports the bmp085 digital barometric pressure
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and temperature sensor from Bosch Sensortec. The datasheet
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is available from their website:
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http://www.bosch-sensortec.com/content/language1/downloads/BST-BMP085-DS000-05.pdf
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A pressure measurement is issued by reading from pressure0_input.
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The return value ranges from 30000 to 110000 pascal with a resulution
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of 1 pascal (0.01 millibar) which enables measurements from 9000m above
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to 500m below sea level.
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The temperature can be read from temp0_input. Values range from
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-400 to 850 representing the ambient temperature in degree celsius
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multiplied by 10.The resolution is 0.1 celsius.
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Because ambient pressure is temperature dependent, a temperature
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measurement will be executed automatically even if the user is reading
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from pressure0_input. This happens if the last temperature measurement
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has been executed more then one second ago.
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To decrease RMS noise from pressure measurements, the bmp085 can
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autonomously calculate the average of up to eight samples. This is
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set up by writing to the oversampling sysfs file. Accepted values
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are 0, 1, 2 and 3. 2^x when x is the value written to this file
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specifies the number of samples used to calculate the ambient pressure.
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RMS noise is specified with six pascal (without averaging) and decreases
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down to 3 pascal when using an oversampling setting of 3.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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* Copyright (c) 2012 Bosch Sensortec GmbH
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* Copyright (c) 2012 Unixphere AB
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*
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* This driver supports the bmp085 digital barometric pressure
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* and temperature sensor from Bosch Sensortec. The datasheet
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* is available from their website:
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* http://www.bosch-sensortec.com/content/language1/downloads/BST-BMP085-DS000-05.pdf
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*
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* A pressure measurement is issued by reading from pressure0_input.
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* The return value ranges from 30000 to 110000 pascal with a resulution
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* of 1 pascal (0.01 millibar) which enables measurements from 9000m above
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* to 500m below sea level.
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*
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* The temperature can be read from temp0_input. Values range from
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* -400 to 850 representing the ambient temperature in degree celsius
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* multiplied by 10.The resolution is 0.1 celsius.
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*
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* Because ambient pressure is temperature dependent, a temperature
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* measurement will be executed automatically even if the user is reading
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* from pressure0_input. This happens if the last temperature measurement
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* has been executed more then one second ago.
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*
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* To decrease RMS noise from pressure measurements, the bmp085 can
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* autonomously calculate the average of up to eight samples. This is
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* set up by writing to the oversampling sysfs file. Accepted values
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* are 0, 1, 2 and 3. 2^x when x is the value written to this file
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* specifies the number of samples used to calculate the ambient pressure.
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* RMS noise is specified with six pascal (without averaging) and decreases
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* down to 3 pascal when using an oversampling setting of 3.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#define BMP085_NAME "bmp085"
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#define BMP085_I2C_ADDRESS 0x77
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#define BMP085_CHIP_ID 0x55
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#define BMP085_CALIBRATION_DATA_START 0xAA
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#define BMP085_CALIBRATION_DATA_LENGTH 11 /* 16 bit values */
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#define BMP085_CHIP_ID_REG 0xD0
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#define BMP085_VERSION_REG 0xD1
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#define BMP085_CTRL_REG 0xF4
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#define BMP085_TEMP_MEASUREMENT 0x2E
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#define BMP085_PRESSURE_MEASUREMENT 0x34
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@ -65,9 +66,6 @@
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#define BMP085_CONVERSION_REGISTER_XLSB 0xF8
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#define BMP085_TEMP_CONVERSION_TIME 5
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#define BMP085_CLIENT_NAME "bmp085"
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static const unsigned short normal_i2c[] = { BMP085_I2C_ADDRESS,
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I2C_CLIENT_END };
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@ -78,20 +76,18 @@ struct bmp085_calibration_data {
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s16 MB, MC, MD;
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};
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/* Each client has this additional data */
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struct bmp085_data {
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struct i2c_client *client;
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struct mutex lock;
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struct bmp085_calibration_data calibration;
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u32 raw_temperature;
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u32 raw_pressure;
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unsigned char oversampling_setting;
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struct i2c_client *client;
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struct mutex lock;
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struct bmp085_calibration_data calibration;
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u8 oversampling_setting;
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u32 raw_temperature;
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u32 raw_pressure;
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u32 temp_measurement_period;
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unsigned long last_temp_measurement;
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s32 b6; /* calculated temperature correction coefficient */
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s32 b6; /* calculated temperature correction coefficient */
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};
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static s32 bmp085_read_calibration_data(struct i2c_client *client)
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{
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u16 tmp[BMP085_CALIBRATION_DATA_LENGTH];
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@ -99,12 +95,12 @@ static s32 bmp085_read_calibration_data(struct i2c_client *client)
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struct bmp085_calibration_data *cali = &(data->calibration);
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s32 status = i2c_smbus_read_i2c_block_data(client,
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BMP085_CALIBRATION_DATA_START,
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BMP085_CALIBRATION_DATA_LENGTH*sizeof(u16),
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(BMP085_CALIBRATION_DATA_LENGTH << 1),
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(u8 *)tmp);
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if (status < 0)
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return status;
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if (status != BMP085_CALIBRATION_DATA_LENGTH*sizeof(u16))
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if (status != (BMP085_CALIBRATION_DATA_LENGTH << 1))
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return -EIO;
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cali->AC1 = be16_to_cpu(tmp[0]);
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@ -121,7 +117,6 @@ static s32 bmp085_read_calibration_data(struct i2c_client *client)
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return 0;
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}
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static s32 bmp085_update_raw_temperature(struct bmp085_data *data)
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{
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u16 tmp;
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@ -130,7 +125,7 @@ static s32 bmp085_update_raw_temperature(struct bmp085_data *data)
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mutex_lock(&data->lock);
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status = i2c_smbus_write_byte_data(data->client, BMP085_CTRL_REG,
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BMP085_TEMP_MEASUREMENT);
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if (status != 0) {
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if (status < 0) {
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dev_err(&data->client->dev,
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"Error while requesting temperature measurement.\n");
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goto exit;
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@ -163,8 +158,9 @@ static s32 bmp085_update_raw_pressure(struct bmp085_data *data)
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mutex_lock(&data->lock);
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status = i2c_smbus_write_byte_data(data->client, BMP085_CTRL_REG,
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BMP085_PRESSURE_MEASUREMENT + (data->oversampling_setting<<6));
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if (status != 0) {
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BMP085_PRESSURE_MEASUREMENT +
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(data->oversampling_setting << 6));
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if (status < 0) {
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dev_err(&data->client->dev,
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"Error while requesting pressure measurement.\n");
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goto exit;
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@ -193,7 +189,6 @@ exit:
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return status;
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}
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/*
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* This function starts the temperature measurement and returns the value
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* in tenth of a degree celsius.
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@ -205,7 +200,7 @@ static s32 bmp085_get_temperature(struct bmp085_data *data, int *temperature)
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int status;
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status = bmp085_update_raw_temperature(data);
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if (status != 0)
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if (status < 0)
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goto exit;
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x1 = ((data->raw_temperature - cali->AC6) * cali->AC5) >> 15;
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@ -222,8 +217,10 @@ exit:
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/*
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* This function starts the pressure measurement and returns the value
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* in millibar. Since the pressure depends on the ambient temperature,
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* a temperature measurement is executed if the last known value is older
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* than one second.
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* a temperature measurement is executed according to the given temperature
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* measurement period (default is 1 sec boundary). This period could vary
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* and needs to be adjusted according to the sensor environment, i.e. if big
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* temperature variations then the temperature needs to be read out often.
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*/
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static s32 bmp085_get_pressure(struct bmp085_data *data, int *pressure)
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{
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@ -234,16 +231,16 @@ static s32 bmp085_get_pressure(struct bmp085_data *data, int *pressure)
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int status;
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/* alt least every second force an update of the ambient temperature */
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if (data->last_temp_measurement == 0 ||
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time_is_before_jiffies(data->last_temp_measurement + 1*HZ)) {
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if ((data->last_temp_measurement == 0) ||
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time_is_before_jiffies(data->last_temp_measurement + 1*HZ)) {
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status = bmp085_get_temperature(data, NULL);
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if (status != 0)
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goto exit;
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if (status < 0)
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return status;
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}
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status = bmp085_update_raw_pressure(data);
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if (status != 0)
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goto exit;
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if (status < 0)
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return status;
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x1 = (data->b6 * data->b6) >> 12;
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x1 *= cali->B2;
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@ -274,15 +271,14 @@ static s32 bmp085_get_pressure(struct bmp085_data *data, int *pressure)
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*pressure = p;
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exit:
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return status;
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return 0;
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}
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/*
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* This function sets the chip-internal oversampling. Valid values are 0..3.
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* The chip will use 2^oversampling samples for internal averaging.
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* This influences the measurement time and the accuracy; larger values
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* increase both. The datasheet gives on overview on how measurement time,
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* increase both. The datasheet gives an overview on how measurement time,
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* accuracy and noise correlate.
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*/
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static void bmp085_set_oversampling(struct bmp085_data *data,
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@ -309,12 +305,16 @@ static ssize_t set_oversampling(struct device *dev,
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struct i2c_client *client = to_i2c_client(dev);
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struct bmp085_data *data = i2c_get_clientdata(client);
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unsigned long oversampling;
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int success = strict_strtoul(buf, 10, &oversampling);
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if (success == 0) {
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int err = kstrtoul(buf, 10, &oversampling);
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if (err == 0) {
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mutex_lock(&data->lock);
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bmp085_set_oversampling(data, oversampling);
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mutex_unlock(&data->lock);
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return count;
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}
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return success;
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return err;
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}
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static ssize_t show_oversampling(struct device *dev,
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@ -322,6 +322,7 @@ static ssize_t show_oversampling(struct device *dev,
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct bmp085_data *data = i2c_get_clientdata(client);
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return sprintf(buf, "%u\n", bmp085_get_oversampling(data));
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}
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static DEVICE_ATTR(oversampling, S_IWUSR | S_IRUGO,
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@ -337,7 +338,7 @@ static ssize_t show_temperature(struct device *dev,
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struct bmp085_data *data = i2c_get_clientdata(client);
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status = bmp085_get_temperature(data, &temperature);
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if (status != 0)
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if (status < 0)
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return status;
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else
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return sprintf(buf, "%d\n", temperature);
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@ -354,7 +355,7 @@ static ssize_t show_pressure(struct device *dev,
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struct bmp085_data *data = i2c_get_clientdata(client);
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status = bmp085_get_pressure(data, &pressure);
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if (status != 0)
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if (status < 0)
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return status;
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else
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return sprintf(buf, "%d\n", pressure);
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@ -386,25 +387,23 @@ static int bmp085_detect(struct i2c_client *client, struct i2c_board_info *info)
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static int bmp085_init_client(struct i2c_client *client)
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{
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unsigned char version;
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int status;
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struct bmp085_data *data = i2c_get_clientdata(client);
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int status = bmp085_read_calibration_data(client);
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if (status < 0)
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return status;
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data->client = client;
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status = bmp085_read_calibration_data(client);
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if (status != 0)
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goto exit;
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version = i2c_smbus_read_byte_data(client, BMP085_VERSION_REG);
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data->last_temp_measurement = 0;
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data->temp_measurement_period = 1*HZ;
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data->oversampling_setting = 3;
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mutex_init(&data->lock);
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dev_info(&data->client->dev, "BMP085 ver. %d.%d found.\n",
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(version & 0x0F), (version & 0xF0) >> 4);
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exit:
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return status;
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return 0;
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}
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static int __devinit bmp085_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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const struct i2c_device_id *id)
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{
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struct bmp085_data *data;
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int err = 0;
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@ -415,14 +414,11 @@ static int __devinit bmp085_probe(struct i2c_client *client,
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goto exit;
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}
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/* default settings after POR */
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data->oversampling_setting = 0x00;
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i2c_set_clientdata(client, data);
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/* Initialize the BMP085 chip */
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err = bmp085_init_client(client);
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if (err != 0)
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if (err < 0)
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goto exit_free;
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/* Register sysfs hooks */
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@ -430,8 +426,9 @@ static int __devinit bmp085_probe(struct i2c_client *client,
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if (err)
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goto exit_free;
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dev_info(&data->client->dev, "Successfully initialized bmp085!\n");
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goto exit;
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dev_info(&client->dev, "Successfully initialized %s!\n", BMP085_NAME);
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return 0;
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exit_free:
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kfree(data);
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@ -441,13 +438,16 @@ exit:
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static int __devexit bmp085_remove(struct i2c_client *client)
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{
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struct bmp085_data *data = i2c_get_clientdata(client);
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sysfs_remove_group(&client->dev.kobj, &bmp085_attr_group);
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kfree(i2c_get_clientdata(client));
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kfree(data);
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return 0;
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}
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static const struct i2c_device_id bmp085_id[] = {
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{ "bmp085", 0 },
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{ BMP085_NAME, 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, bmp085_id);
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@ -455,7 +455,7 @@ MODULE_DEVICE_TABLE(i2c, bmp085_id);
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static struct i2c_driver bmp085_driver = {
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.driver = {
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.owner = THIS_MODULE,
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.name = "bmp085"
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.name = BMP085_NAME
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},
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.id_table = bmp085_id,
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.probe = bmp085_probe,
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@ -467,6 +467,6 @@ static struct i2c_driver bmp085_driver = {
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module_i2c_driver(bmp085_driver);
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MODULE_AUTHOR("Christoph Mair <christoph.mair@gmail.com");
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MODULE_AUTHOR("Christoph Mair <christoph.mair@gmail.com>");
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MODULE_DESCRIPTION("BMP085 driver");
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MODULE_LICENSE("GPL");
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