This patch adds support for the Bosch Sensortec bmp085 digital barometer to the iio subsystem.
Signed-off-by: Matthias Brugger <[email protected]> --- drivers/staging/iio/Kconfig | 1 + drivers/staging/iio/Makefile | 1 + drivers/staging/iio/barometer/Kconfig | 12 + drivers/staging/iio/barometer/Makefile | 5 + drivers/staging/iio/barometer/baro.h | 8 + drivers/staging/iio/barometer/bmp085.c | 398 ++++++++++++++++++++++++++++++++ drivers/staging/iio/barometer/bmp085.h | 108 +++++++++ 7 files changed, 533 insertions(+), 0 deletions(-) create mode 100644 drivers/staging/iio/barometer/Kconfig create mode 100644 drivers/staging/iio/barometer/Makefile create mode 100644 drivers/staging/iio/barometer/baro.h create mode 100644 drivers/staging/iio/barometer/bmp085.c create mode 100644 drivers/staging/iio/barometer/bmp085.h diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig index ed48815..d5ca09a 100644 --- a/drivers/staging/iio/Kconfig +++ b/drivers/staging/iio/Kconfig @@ -46,6 +46,7 @@ source "drivers/staging/iio/gyro/Kconfig" source "drivers/staging/iio/imu/Kconfig" source "drivers/staging/iio/light/Kconfig" source "drivers/staging/iio/magnetometer/Kconfig" +source "drivers/staging/iio/barometer/Kconfig" source "drivers/staging/iio/trigger/Kconfig" diff --git a/drivers/staging/iio/Makefile b/drivers/staging/iio/Makefile index e909674..73112b2 100644 --- a/drivers/staging/iio/Makefile +++ b/drivers/staging/iio/Makefile @@ -16,3 +16,4 @@ obj-y += imu/ obj-y += light/ obj-y += trigger/ obj-y += magnetometer/ +obj-y += barometer/ diff --git a/drivers/staging/iio/barometer/Kconfig b/drivers/staging/iio/barometer/Kconfig new file mode 100644 index 0000000..d5942e9 --- /dev/null +++ b/drivers/staging/iio/barometer/Kconfig @@ -0,0 +1,12 @@ +# +# IIO Digital Barometer Sensor drivers configuration +# +comment "Digital barometer sensors" + +config BMP085 + + tristate "BMP085 Barometer Sensor I2C driver" + depends on I2C + help + Say yes here to build support for Bosch Sensortec BMP085, + digital barometer sensor. diff --git a/drivers/staging/iio/barometer/Makefile b/drivers/staging/iio/barometer/Makefile new file mode 100644 index 0000000..3234d96 --- /dev/null +++ b/drivers/staging/iio/barometer/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for digital barometer sensor drivers +# + +obj-$(CONFIG_BMP085) += bmp085.o diff --git a/drivers/staging/iio/barometer/baro.h b/drivers/staging/iio/barometer/baro.h new file mode 100644 index 0000000..a25e4cd --- /dev/null +++ b/drivers/staging/iio/barometer/baro.h @@ -0,0 +1,8 @@ + +#include "../sysfs.h" + +/* Barometer types of attribute */ + +#define IIO_DEV_ATTR_BARO_PRESSURE(_mode, _show, _store, _addr) \ + IIO_DEVICE_ATTR(baro_pressure_input, _mode, _show, NULL, _addr) + diff --git a/drivers/staging/iio/barometer/bmp085.c b/drivers/staging/iio/barometer/bmp085.c new file mode 100644 index 0000000..580bd57 --- /dev/null +++ b/drivers/staging/iio/barometer/bmp085.c @@ -0,0 +1,398 @@ +/** + * Bosch Sensortec BMP085 Digital Pressure Sensor + * + * Written by: Matthias Brugger <[email protected]> + * + * Copyright (C) 2010 Fraunhofer Institute for Integrated Circuits + * + * 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., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/mutex.h> +#include <linux/delay.h> +#include <linux/time.h> +#include <linux/mutex.h> + +#include "bmp085.h" + +int oss = 3; +module_param(oss, int , S_IRUSR); +MODULE_PARM_DESC(oss, "Oversampling setting [0-3]"); + +/************************************************************************** + * Calculation of temperature and pressure + **************************************************************************/ +static short bmp085_calc_temperature(struct i2c_client *client, + unsigned long ut) +{ + struct bmp085_data *data = i2c_get_clientdata(client); + long x1, x2; + short temp; + + x1 = ((long) ut - (long) data->ac6) * (long) data->ac5 >> 15; + x2 = ((long) data->mc << 11) / (x1 + data->md); + data->b5 = x1 + x2; + temp = ((data->b5 + 8) >> 4); + + return temp; +} + +static long bmp085_calc_pressure(struct i2c_client *client, unsigned long up) +{ + struct bmp085_data *data = i2c_get_clientdata(client); + long b6, x1, x2, x3, b3; + unsigned long b4, b7; + long pressure, p; + long tmp; + + b6 = data->b5 - 4000; + x1 = (data->b2 * (b6 * b6 / (1<<12))) / (1<<11); + x2 = data->ac2 * b6 / (1<<11); + x3 = x1 + x2; + b3 = (((data->ac1 * 4 + x3) << data->oss) + 2) / 4; + + x1 = data->ac3 * b6 / (1<<13); + x2 = (data->b1 * ((b6 * b6) / (1<<12))) / (1<<16); + x3 = ((x1 + x2) + 2) / (1<<2); + b4 = data->ac4 * (unsigned long) (x3 + 32768) / (1<<15); + b7 = ((unsigned long)up - b3) * (50000 >> data->oss); + + if (b7 < 0x80000000) + p = (b7 * 2) / b4; + else + p = (b7 / b4) * 2; + tmp = (p / (1<<8)) * (p / (1<<8)); + x1 = (tmp * 3038) / (1<<16); + x2 = (-7357 * p) / (1<<16); + pressure = p + ((x1 + x2 + 3791) / (1<<4)); + + return pressure; +} + +/************************************************************************** + * Digital interface to sensor + **************************************************************************/ + +static short bmp085_read_temp(struct i2c_client *client) +{ + s32 ret; + short temp; + struct bmp085_data *data = i2c_get_clientdata(client); + + mutex_lock(&data->bmp085_lock); + ret = i2c_smbus_write_byte_data(client, BMP085_START_CONV, + BMP085_START_TEMP); + mutex_unlock(&data->bmp085_lock); + if (ret < 0) { + dev_warn(&client->dev, "starting temperature conversation " + "failed\n"); + return ret; + } + + msleep(5); + ret = i2c_smbus_read_i2c_block_data(client, BMP085_REG_CONV, 2, + data->data); + if (ret < 0) { + dev_warn(&client->dev, "reading ut failed, value is %#x\n" + , ret); + return ret; + } + + data->ut = (data->data[0] << 8) | data->data[1]; + + temp = bmp085_calc_temperature(client, data->ut); + + return temp; +} + +static long bmp085_read_pressure(struct i2c_client *client) +{ + unsigned long up = 0; + int ret; + u8 xlsb, ret1, ret2; + long pressure; + u8 reg; + int time_delay[4] = {5, 8, 14, 26}; + struct bmp085_data *data = i2c_get_clientdata(client); + + if (data->oss == 0) + reg = BMP085_START_PRESS_OSRS0; + else if (data->oss == 1) + reg = BMP085_START_PRESS_OSRS1; + else if (data->oss == 2) + reg = BMP085_START_PRESS_OSRS2; + else if (data->oss == 3) + reg = BMP085_START_PRESS_OSRS3; + else { + dev_warn(&client->dev, "undefined oss value, use oss = 0\n"); + data->oss = 0; + reg = BMP085_START_PRESS_OSRS0; + } + + mutex_lock(&data->bmp085_lock); + ret = i2c_smbus_write_byte_data(client, BMP085_START_CONV, reg); + mutex_unlock(&data->bmp085_lock); + if (ret < 0) + return ret; + + msleep(time_delay[data->oss]); + + mutex_lock(&data->bmp085_lock); + ret1 = i2c_smbus_read_byte_data(client, 0xf6); + ret2 = i2c_smbus_read_byte_data(client, 0xf7); + xlsb = i2c_smbus_read_byte_data(client, 0xf8); + mutex_unlock(&data->bmp085_lock); + + up = (((unsigned long) ret1 << 16) | ((unsigned long) ret2 << 8) + | (unsigned long) xlsb) >> (8 - data->oss); + data->up = up; + + pressure = bmp085_calc_pressure(client, up); + + return pressure; +} + +/************************************************************************** + * sysfs attributes + **************************************************************************/ +static ssize_t barometer_show_temp(struct device *dev, + struct device_attribute *da, char *buf) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bmp085_data *data = indio_dev->dev_data; + struct i2c_client *client = data->client; + long status; + + status = bmp085_read_temp(client); + if (status < 0) + dev_warn(&client->dev, "error reading temperature: %ld\n", + status); + + data->temp = status; + + return sprintf(buf, "%d\n", data->temp); +} +static IIO_DEV_ATTR_TEMP_RAW(barometer_show_temp); + +/** + * In standard mode, the temperature has to be read every second before the + * pressure can be read. We leave this semantics to the userspace, if later + * on a trigger based reading will be implemented, this should be taken into + * account. + */ +static ssize_t barometer_show_pressure(struct device *dev, + struct device_attribute *da, char *buf) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bmp085_data *data = iio_dev_get_devdata(indio_dev); + struct i2c_client *client = data->client; + long status; + + status = bmp085_read_pressure(client); + if (status < 0) + dev_warn(&client->dev, "error reading pressure: %ld\n", status); + + data->pressure = status; + + return sprintf(buf, "%ld\n", data->pressure); +} +static IIO_DEV_ATTR_BARO_PRESSURE(S_IRUGO, barometer_show_pressure, NULL, 0); + +static ssize_t barometer_show_id_version(struct device *dev, + struct device_attribute *da, char *buf) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bmp085_data *data = iio_dev_get_devdata(indio_dev); + + return sprintf(buf, "%x_%x\n", data->chip_id, data->chip_version); +} +static IIO_DEV_ATTR_REV(barometer_show_id_version); + +static ssize_t barometer_show_oss(struct device *dev, + struct device_attribute *da, char *buf) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bmp085_data *data = iio_dev_get_devdata(indio_dev); + + return sprintf(buf, "%d\n", data->oss); +} +static IIO_DEV_ATTR_SAMP_FREQ(S_IRUGO, barometer_show_oss, NULL); + +static IIO_CONST_ATTR_TEMP_SCALE("0.1"); + +static struct attribute *bmp085_attributes[] = { + &iio_dev_attr_temp_raw.dev_attr.attr, + &iio_dev_attr_baro_pressure_input.dev_attr.attr, + &iio_dev_attr_revision.dev_attr.attr, + &iio_dev_attr_sampling_frequency.dev_attr.attr, + &iio_const_attr_temp_scale.dev_attr.attr, + NULL +}; + +static const struct attribute_group bmp085_attr_group = { + .attrs = bmp085_attributes, +}; + +/************************************************************************** + * Calibration data processing + **************************************************************************/ + +static int bmp085_init_client(struct i2c_client *client) +{ + struct bmp085_data *data = i2c_get_clientdata(client); + int i; + + i = i2c_smbus_read_i2c_block_data(client, BMP085_REG_CHIP_ID, 1, + &data->chip_id); + if (i < 0) + dev_warn(&client->dev, "Chip ID not read\n"); + + i = i2c_smbus_read_i2c_block_data(client, BMP085_REG_VERSION, 1, + &data->chip_version); + if (i < 0) + dev_warn(&client->dev, "Version not read\n"); + + i = i2c_smbus_read_i2c_block_data(client, BMP085_REG_PROM, BMP085_PROM_LENGTH, + data->data); + if (i < 0) + dev_warn(&client->dev, "Unable to read %d bytes from address " + "%#x\n", BMP085_PROM_LENGTH, BMP085_REG_PROM); + + data->ac1 = (data->data[0] << 8) | data->data[1]; + data->ac2 = (data->data[2] << 8) | data->data[3]; + data->ac3 = (data->data[4] << 8) | data->data[5]; + data->ac4 = (data->data[6] << 8) | data->data[7]; + data->ac5 = (data->data[8] << 8) | data->data[9]; + data->ac6 = (data->data[10] << 8) | data->data[11]; + data->b1 = (data->data[12] << 8) | data->data[13]; + data->b2 = (data->data[14] << 8) | data->data[15]; + data->mb = (data->data[16] << 8) | data->data[17]; + data->mc = (data->data[18] << 8) | data->data[19]; + data->md = (data->data[20] << 8) | data->data[21]; + + return 0; +} + +static int bmp085_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); + struct bmp085_data *data; + int status = 0; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_WORD_DATA)) + return -EIO; + + /* Allocate driver data */ + data = kzalloc(sizeof(struct bmp085_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + if ((oss < 0) || (oss > 3)) { + status = -EINVAL; + goto err; + } + data->oss = oss; + + data->client = client; + i2c_set_clientdata(client, data); + + /* Initialize the BMP085 chip */ + bmp085_init_client(client); + + mutex_init(&data->bmp085_lock); + + /* Register with IIO */ + data->indio_dev = iio_allocate_device(); + if (data->indio_dev == NULL) { + status = -ENOMEM; + goto err; + } + + data->indio_dev->dev.parent = &client->dev; + data->indio_dev->attrs = &bmp085_attr_group; + data->indio_dev->dev_data = (void *)(data); + data->indio_dev->driver_module = THIS_MODULE; + data->indio_dev->modes = INDIO_DIRECT_MODE; + + status = iio_device_register(data->indio_dev); + if (status < 0) + goto err_iio; + + return 0; + +err_iio: + kfree(data->indio_dev); +err: + kfree(data); + return status; +} + +static int __devexit bmp085_remove(struct i2c_client *client) +{ + struct bmp085_data *data = i2c_get_clientdata(client); + + iio_device_unregister(data->indio_dev); + iio_free_device(data->indio_dev); + + kfree(data); + + return 0; +} + +static const struct i2c_device_id bmp085_id[] = { + { "bmp085", 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, bmp085_id); + +static struct i2c_driver bmp085_drv = { + .driver = { + .name = "bmp085", + .owner = THIS_MODULE, + }, + .suspend = NULL, + .resume = NULL, + .probe = bmp085_probe, + .remove = __devexit_p(bmp085_remove), + .id_table = bmp085_id, +}; + +/*-------------------------------------------------------------------------*/ + +static int __init bmp085_init_module(void) +{ + printk(KERN_INFO"bmp085 loading...\n"); + + return i2c_add_driver(&bmp085_drv); +} + +static void __exit bmp085_exit_module(void) +{ + i2c_del_driver(&bmp085_drv); +} + +MODULE_AUTHOR("Matthias Brugger <[email protected]>"); +MODULE_DESCRIPTION("I2c device driver for BMP085 barometererator sensor"); +MODULE_LICENSE("GPL"); + +module_init(bmp085_init_module); +module_exit(bmp085_exit_module); diff --git a/drivers/staging/iio/barometer/bmp085.h b/drivers/staging/iio/barometer/bmp085.h new file mode 100644 index 0000000..aec2ee4 --- /dev/null +++ b/drivers/staging/iio/barometer/bmp085.h @@ -0,0 +1,108 @@ +#ifndef BMP085_H +#define BMP085_H + +#include "../iio.h" +#include "baro.h" + +#define BMP085_REG_CONV 0xF6 /* Temperature/pressure value UT or UP */ +#define BMP085_REG_CONV_XLS 0xF8 + +#define BMP085_REG_PROM 0xAA +#define BMP085_PROM_LENGTH 22 + +#define BMP085_REG_AC1 0xAA +#define BMP085_REG_AC2 0xAC +#define BMP085_REG_AC3 0xAE +#define BMP085_REG_AC4 0xB0 +#define BMP085_REG_AC5 0xB2 +#define BMP085_REG_AC6 0xB4 +#define BMP085_REG_B1 0xB6 +#define BMP085_REG_B2 0xB8 +#define BMP085_REG_MB 0xBA +#define BMP085_REG_MC 0xBC +#define BMP085_REG_MD 0xBE + +#define BMP085_START_CONV 0xF4 + +#define BMP085_START_TEMP 0x2E /* wait 4.5 ms */ + +#define BMP085_START_PRESS_OSRS0 0x34 /* wait 4.5 ms */ +#define BMP085_START_PRESS_OSRS1 0x74 /* wait 7.5 ms */ +#define BMP085_START_PRESS_OSRS2 0xB4 /* wait 13.5 ms */ +#define BMP085_START_PRESS_OSRS3 0xF4 /* wait 25.5 ms */ + +#define BMP085_REG_CHIP_ID 0xD0 +#define BMP085_REG_VERSION 0xD1 +#define BMP085_CHIP_ID 0x55 + +/* + * data structure for every sensor + * + * @client i2c client + * @ indio_dev iio device representation + * + * @bmp085_lock mutex to synchronize parallel reads and writes + * + * @oss oversampling setting, determines how accurate the chip works + * @temp holding actual temperature in 0.1°C + * @pressure holding actual pressure in pascal + * + * @ac1 calibration value read at start-up + * @ac2 calibration value read at start-up + * @ac3 calibration value read at start-up + * @ac4 calibration value read at start-up + * @ac5 calibration value read at start-up + * @ac6 calibration value read at start-up + * + * @b1 calibration value read at start-up + * @b2 calibration value read at start-up + * @b3 calibration value read at start-up + * + * @mb calibration value read at start-up + * @mc calibration value read at start-up + * @md calibration value read at start-up + * + * @ut raw data to compute temperature + * @up raw data to compute pressure + * + * @chip_id id of the chip + * @chip_version version of the chip + * + * @data array to read initial calib data as a bulk + */ +struct bmp085_data { + struct i2c_client *client; + struct iio_dev *indio_dev; + + struct mutex bmp085_lock; + + int oss; + s16 temp; + long pressure; + + short ac1; + short ac2; + short ac3; + unsigned short ac4; + unsigned short ac5; + unsigned short ac6; + + short b1; + short b2; + long b5; + + short mb; + short mc; + short md; + + unsigned long ut; + unsigned long up; + + u8 chip_id; + u8 chip_version; + + unsigned char data[22]; +}; + + +#endif -- 1.5.6.5 _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
