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