This patch adds support for the Bosch Sensortec bmp085 digital
barometer to the iio subsystem.
Signed-off-by: Matthias Brugger <m_brugger@xxxxxx>
---
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 <m_brugger@xxxxxx>
+ *
+ * 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 <matthias.brugger@xxxxxxxxxxxxxxxxx>");
+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
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