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misc: clean up bmp085 driver

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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 2012-04-09 22:16:15 +02:00 committed by Greg Kroah-Hartman
parent 0ed0d579cb
commit e939ca0a63
1 changed files with 103 additions and 103 deletions
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206
drivers/misc/bmp085.c
View File

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