/* 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 and bmp18x digital barometric pressure
+ * and temperature sensors from Bosch Sensortec. The datasheets
+ * are available from their website:
+ * http://www.bosch-sensortec.com/content/language1/downloads/BST-BMP085-DS000-05.pdf
+ * http://www.bosch-sensortec.com/content/language1/downloads/BST-BMP180-DS000-07.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>
+#include <linux/of.h>
+#include "bmp085.h"
-
-#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
#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 };
-
struct bmp085_calibration_data {
s16 AC1, AC2, AC3;
u16 AC4, AC5, AC6;
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 device *dev;
+ struct regmap *regmap;
+ 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 */
+ u8 chip_id;
+ s32 b6; /* calculated temperature correction coefficient */
};
-
-static s32 bmp085_read_calibration_data(struct i2c_client *client)
+static s32 bmp085_read_calibration_data(struct bmp085_data *data)
{
u16 tmp[BMP085_CALIBRATION_DATA_LENGTH];
- struct bmp085_data *data = i2c_get_clientdata(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),
- (u8 *)tmp);
+ s32 status = regmap_bulk_read(data->regmap,
+ BMP085_CALIBRATION_DATA_START, (u8 *)tmp,
+ (BMP085_CALIBRATION_DATA_LENGTH << 1));
if (status < 0)
return status;
- if (status != BMP085_CALIBRATION_DATA_LENGTH*sizeof(u16))
- return -EIO;
-
cali->AC1 = be16_to_cpu(tmp[0]);
cali->AC2 = be16_to_cpu(tmp[1]);
cali->AC3 = be16_to_cpu(tmp[2]);
return 0;
}
-
static s32 bmp085_update_raw_temperature(struct bmp085_data *data)
{
u16 tmp;
s32 status;
mutex_lock(&data->lock);
- status = i2c_smbus_write_byte_data(data->client, BMP085_CTRL_REG,
- BMP085_TEMP_MEASUREMENT);
- if (status != 0) {
- dev_err(&data->client->dev,
+ status = regmap_write(data->regmap, BMP085_CTRL_REG,
+ BMP085_TEMP_MEASUREMENT);
+ if (status < 0) {
+ dev_err(data->dev,
"Error while requesting temperature measurement.\n");
goto exit;
}
msleep(BMP085_TEMP_CONVERSION_TIME);
- status = i2c_smbus_read_i2c_block_data(data->client,
- BMP085_CONVERSION_REGISTER_MSB, sizeof(tmp), (u8 *)&tmp);
- if (status < 0)
- goto exit;
- if (status != sizeof(tmp)) {
- dev_err(&data->client->dev,
+ status = regmap_bulk_read(data->regmap, BMP085_CONVERSION_REGISTER_MSB,
+ &tmp, sizeof(tmp));
+ if (status < 0) {
+ dev_err(data->dev,
"Error while reading temperature measurement result\n");
- status = -EIO;
goto exit;
}
data->raw_temperature = be16_to_cpu(tmp);
s32 status;
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) {
- dev_err(&data->client->dev,
+ status = regmap_write(data->regmap, BMP085_CTRL_REG,
+ BMP085_PRESSURE_MEASUREMENT +
+ (data->oversampling_setting << 6));
+ if (status < 0) {
+ dev_err(data->dev,
"Error while requesting pressure measurement.\n");
goto exit;
}
msleep(2+(3 << data->oversampling_setting));
/* copy data into a u32 (4 bytes), but skip the first byte. */
- status = i2c_smbus_read_i2c_block_data(data->client,
- BMP085_CONVERSION_REGISTER_MSB, 3, ((u8 *)&tmp)+1);
- if (status < 0)
- goto exit;
- if (status != 3) {
- dev_err(&data->client->dev,
+ status = regmap_bulk_read(data->regmap, BMP085_CONVERSION_REGISTER_MSB,
+ ((u8 *)&tmp)+1, 3);
+ if (status < 0) {
+ dev_err(data->dev,
"Error while reading pressure measurement results\n");
- status = -EIO;
goto exit;
}
data->raw_pressure = be32_to_cpu((tmp));
return status;
}
-
/*
* This function starts the temperature measurement and returns the value
* in tenth of a degree celsius.
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;
/*
* 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)
{
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;
*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,
struct device_attribute *attr,
const char *buf, size_t count)
{
- struct i2c_client *client = to_i2c_client(dev);
- struct bmp085_data *data = i2c_get_clientdata(client);
+ struct bmp085_data *data = dev_get_drvdata(dev);
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,
struct device_attribute *attr, char *buf)
{
- struct i2c_client *client = to_i2c_client(dev);
- struct bmp085_data *data = i2c_get_clientdata(client);
+ struct bmp085_data *data = dev_get_drvdata(dev);
+
return sprintf(buf, "%u\n", bmp085_get_oversampling(data));
}
static DEVICE_ATTR(oversampling, S_IWUSR | S_IRUGO,
{
int temperature;
int status;
- struct i2c_client *client = to_i2c_client(dev);
- struct bmp085_data *data = i2c_get_clientdata(client);
+ struct bmp085_data *data = dev_get_drvdata(dev);
status = bmp085_get_temperature(data, &temperature);
- if (status != 0)
+ if (status < 0)
return status;
else
return sprintf(buf, "%d\n", temperature);
{
int pressure;
int status;
- struct i2c_client *client = to_i2c_client(dev);
- struct bmp085_data *data = i2c_get_clientdata(client);
+ struct bmp085_data *data = dev_get_drvdata(dev);
status = bmp085_get_pressure(data, &pressure);
- if (status != 0)
+ if (status < 0)
return status;
else
return sprintf(buf, "%d\n", pressure);
.attrs = bmp085_attributes,
};
-static int bmp085_detect(struct i2c_client *client, struct i2c_board_info *info)
+int bmp085_detect(struct device *dev)
{
- if (client->addr != BMP085_I2C_ADDRESS)
- return -ENODEV;
+ struct bmp085_data *data = dev_get_drvdata(dev);
+ unsigned int id;
+ int ret;
- if (i2c_smbus_read_byte_data(client, BMP085_CHIP_ID_REG) != BMP085_CHIP_ID)
+ ret = regmap_read(data->regmap, BMP085_CHIP_ID_REG, &id);
+ if (ret < 0)
+ return ret;
+
+ if (id != data->chip_id)
return -ENODEV;
return 0;
}
+EXPORT_SYMBOL_GPL(bmp085_detect);
-static int bmp085_init_client(struct i2c_client *client)
+static void __init bmp085_get_of_properties(struct bmp085_data *data)
{
- unsigned char version;
- int status;
- struct bmp085_data *data = i2c_get_clientdata(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);
+#ifdef CONFIG_OF
+ struct device_node *np = data->dev->of_node;
+ u32 prop;
+
+ if (!np)
+ return;
+
+ if (!of_property_read_u32(np, "chip-id", &prop))
+ data->chip_id = prop & 0xff;
+
+ if (!of_property_read_u32(np, "temp-measurement-period", &prop))
+ data->temp_measurement_period = (prop/100)*HZ;
+
+ if (!of_property_read_u32(np, "default-oversampling", &prop))
+ data->oversampling_setting = prop & 0xff;
+#endif
+}
+
+static int bmp085_init_client(struct bmp085_data *data)
+{
+ int status = bmp085_read_calibration_data(data);
+
+ if (status < 0)
+ return status;
+
+ /* default settings */
+ data->chip_id = BMP085_CHIP_ID;
data->last_temp_measurement = 0;
+ data->temp_measurement_period = 1*HZ;
data->oversampling_setting = 3;
+
+ bmp085_get_of_properties(data);
+
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)
+struct regmap_config bmp085_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8
+};
+EXPORT_SYMBOL_GPL(bmp085_regmap_config);
+
+__devinit int bmp085_probe(struct device *dev, struct regmap *regmap)
{
struct bmp085_data *data;
int err = 0;
goto exit;
}
- /* default settings after POR */
- data->oversampling_setting = 0x00;
-
- i2c_set_clientdata(client, data);
+ dev_set_drvdata(dev, data);
+ data->dev = dev;
+ data->regmap = regmap;
/* Initialize the BMP085 chip */
- err = bmp085_init_client(client);
- if (err != 0)
+ err = bmp085_init_client(data);
+ if (err < 0)
goto exit_free;
+ err = bmp085_detect(dev);
+ if (err < 0) {
+ dev_err(dev, "%s: chip_id failed!\n", BMP085_NAME);
+ goto exit_free;
+ }
+
/* Register sysfs hooks */
- err = sysfs_create_group(&client->dev.kobj, &bmp085_attr_group);
+ err = sysfs_create_group(&dev->kobj, &bmp085_attr_group);
if (err)
goto exit_free;
- dev_info(&data->client->dev, "Successfully initialized bmp085!\n");
- goto exit;
+ dev_info(dev, "Successfully initialized %s!\n", BMP085_NAME);
+
+ return 0;
exit_free:
kfree(data);
exit:
return err;
}
+EXPORT_SYMBOL_GPL(bmp085_probe);
-static int __devexit bmp085_remove(struct i2c_client *client)
+int bmp085_remove(struct device *dev)
{
- sysfs_remove_group(&client->dev.kobj, &bmp085_attr_group);
- kfree(i2c_get_clientdata(client));
- return 0;
-}
+ struct bmp085_data *data = dev_get_drvdata(dev);
-static const struct i2c_device_id bmp085_id[] = {
- { "bmp085", 0 },
- { }
-};
-MODULE_DEVICE_TABLE(i2c, bmp085_id);
-
-static struct i2c_driver bmp085_driver = {
- .driver = {
- .owner = THIS_MODULE,
- .name = "bmp085"
- },
- .id_table = bmp085_id,
- .probe = bmp085_probe,
- .remove = __devexit_p(bmp085_remove),
-
- .detect = bmp085_detect,
- .address_list = normal_i2c
-};
+ sysfs_remove_group(&data->dev->kobj, &bmp085_attr_group);
+ kfree(data);
-module_i2c_driver(bmp085_driver);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bmp085_remove);
-MODULE_AUTHOR("Christoph Mair <christoph.mair@gmail.com");
+MODULE_AUTHOR("Christoph Mair <christoph.mair@gmail.com>");
MODULE_DESCRIPTION("BMP085 driver");
MODULE_LICENSE("GPL");
projects / cascardo / linux.git / blobdiff