From: Eric Andersson Date: Mon, 9 Apr 2012 20:16:15 +0000 (+0200) Subject: misc: clean up bmp085 driver X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=e939ca0a63627d6b2205dd945833ee7da4fc181a;p=deliverable%2Flinux.git 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 Signed-off-by: Eric Andersson Reviewed-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/misc/bmp085.c b/drivers/misc/bmp085.c index 76c3064629f1..6f572bc21879 100644 --- a/drivers/misc/bmp085.c +++ b/drivers/misc/bmp085.c @@ -1,62 +1,63 @@ /* Copyright (c) 2010 Christoph Mair - - 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 +#include #include #include #include #include - +#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 "); MODULE_DESCRIPTION("BMP085 driver"); MODULE_LICENSE("GPL");