diff options
Diffstat (limited to 'drivers/misc/bmp085.c')
| -rw-r--r-- | drivers/misc/bmp085.c | 506 |
1 files changed, 0 insertions, 506 deletions
diff --git a/drivers/misc/bmp085.c b/drivers/misc/bmp085.c deleted file mode 100644 index 9b313f7810f5..000000000000 --- a/drivers/misc/bmp085.c +++ /dev/null @@ -1,506 +0,0 @@ -/* Copyright (c) 2010 Christoph Mair <christoph.mair@gmail.com> - * 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/slab.h> -#include <linux/of.h> -#include "bmp085.h" -#include <linux/interrupt.h> -#include <linux/completion.h> -#include <linux/gpio.h> - -#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_CTRL_REG 0xF4 -#define BMP085_TEMP_MEASUREMENT 0x2E -#define BMP085_PRESSURE_MEASUREMENT 0x34 -#define BMP085_CONVERSION_REGISTER_MSB 0xF6 -#define BMP085_CONVERSION_REGISTER_LSB 0xF7 -#define BMP085_CONVERSION_REGISTER_XLSB 0xF8 -#define BMP085_TEMP_CONVERSION_TIME 5 - -struct bmp085_calibration_data { - s16 AC1, AC2, AC3; - u16 AC4, AC5, AC6; - s16 B1, B2; - s16 MB, MC, MD; -}; - -struct bmp085_data { - 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; - u8 chip_id; - s32 b6; /* calculated temperature correction coefficient */ - int irq; - struct completion done; -}; - -static irqreturn_t bmp085_eoc_isr(int irq, void *devid) -{ - struct bmp085_data *data = devid; - - complete(&data->done); - - return IRQ_HANDLED; -} - -static s32 bmp085_read_calibration_data(struct bmp085_data *data) -{ - u16 tmp[BMP085_CALIBRATION_DATA_LENGTH]; - struct bmp085_calibration_data *cali = &(data->calibration); - s32 status = regmap_bulk_read(data->regmap, - BMP085_CALIBRATION_DATA_START, (u8 *)tmp, - (BMP085_CALIBRATION_DATA_LENGTH << 1)); - if (status < 0) - return status; - - cali->AC1 = be16_to_cpu(tmp[0]); - cali->AC2 = be16_to_cpu(tmp[1]); - cali->AC3 = be16_to_cpu(tmp[2]); - cali->AC4 = be16_to_cpu(tmp[3]); - cali->AC5 = be16_to_cpu(tmp[4]); - cali->AC6 = be16_to_cpu(tmp[5]); - cali->B1 = be16_to_cpu(tmp[6]); - cali->B2 = be16_to_cpu(tmp[7]); - cali->MB = be16_to_cpu(tmp[8]); - cali->MC = be16_to_cpu(tmp[9]); - cali->MD = be16_to_cpu(tmp[10]); - return 0; -} - -static s32 bmp085_update_raw_temperature(struct bmp085_data *data) -{ - u16 tmp; - s32 status; - - mutex_lock(&data->lock); - - init_completion(&data->done); - - 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; - } - wait_for_completion_timeout(&data->done, 1 + msecs_to_jiffies( - BMP085_TEMP_CONVERSION_TIME)); - - 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"); - goto exit; - } - data->raw_temperature = be16_to_cpu(tmp); - data->last_temp_measurement = jiffies; - status = 0; /* everything ok, return 0 */ - -exit: - mutex_unlock(&data->lock); - return status; -} - -static s32 bmp085_update_raw_pressure(struct bmp085_data *data) -{ - u32 tmp = 0; - s32 status; - - mutex_lock(&data->lock); - - init_completion(&data->done); - - 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; - } - - /* wait for the end of conversion */ - wait_for_completion_timeout(&data->done, 1 + msecs_to_jiffies( - 2+(3 << data->oversampling_setting))); - /* copy data into a u32 (4 bytes), but skip the first byte. */ - 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"); - goto exit; - } - data->raw_pressure = be32_to_cpu((tmp)); - data->raw_pressure >>= (8-data->oversampling_setting); - status = 0; /* everything ok, return 0 */ - -exit: - mutex_unlock(&data->lock); - return status; -} - -/* - * This function starts the temperature measurement and returns the value - * in tenth of a degree celsius. - */ -static s32 bmp085_get_temperature(struct bmp085_data *data, int *temperature) -{ - struct bmp085_calibration_data *cali = &data->calibration; - long x1, x2; - int status; - - status = bmp085_update_raw_temperature(data); - if (status < 0) - goto exit; - - x1 = ((data->raw_temperature - cali->AC6) * cali->AC5) >> 15; - x2 = (cali->MC << 11) / (x1 + cali->MD); - data->b6 = x1 + x2 - 4000; - /* if NULL just update b6. Used for pressure only measurements */ - if (temperature != NULL) - *temperature = (x1+x2+8) >> 4; - -exit: - return status; -} - -/* - * 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 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) -{ - struct bmp085_calibration_data *cali = &data->calibration; - s32 x1, x2, x3, b3; - u32 b4, b7; - s32 p; - 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)) { - status = bmp085_get_temperature(data, NULL); - if (status < 0) - return status; - } - - status = bmp085_update_raw_pressure(data); - if (status < 0) - return status; - - x1 = (data->b6 * data->b6) >> 12; - x1 *= cali->B2; - x1 >>= 11; - - x2 = cali->AC2 * data->b6; - x2 >>= 11; - - x3 = x1 + x2; - - b3 = (((((s32)cali->AC1) * 4 + x3) << data->oversampling_setting) + 2); - b3 >>= 2; - - x1 = (cali->AC3 * data->b6) >> 13; - x2 = (cali->B1 * ((data->b6 * data->b6) >> 12)) >> 16; - x3 = (x1 + x2 + 2) >> 2; - b4 = (cali->AC4 * (u32)(x3 + 32768)) >> 15; - - b7 = ((u32)data->raw_pressure - b3) * - (50000 >> data->oversampling_setting); - p = ((b7 < 0x80000000) ? ((b7 << 1) / b4) : ((b7 / b4) * 2)); - - x1 = p >> 8; - x1 *= x1; - x1 = (x1 * 3038) >> 16; - x2 = (-7357 * p) >> 16; - p += (x1 + x2 + 3791) >> 4; - - *pressure = p; - - 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 an overview on how measurement time, - * accuracy and noise correlate. - */ -static void bmp085_set_oversampling(struct bmp085_data *data, - unsigned char oversampling) -{ - if (oversampling > 3) - oversampling = 3; - data->oversampling_setting = oversampling; -} - -/* - * Returns the currently selected oversampling. Range: 0..3 - */ -static unsigned char bmp085_get_oversampling(struct bmp085_data *data) -{ - return data->oversampling_setting; -} - -/* sysfs callbacks */ -static ssize_t set_oversampling(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct bmp085_data *data = dev_get_drvdata(dev); - unsigned long oversampling; - 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 err; -} - -static ssize_t show_oversampling(struct device *dev, - struct device_attribute *attr, char *buf) -{ - 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, - show_oversampling, set_oversampling); - - -static ssize_t show_temperature(struct device *dev, - struct device_attribute *attr, char *buf) -{ - int temperature; - int status; - struct bmp085_data *data = dev_get_drvdata(dev); - - status = bmp085_get_temperature(data, &temperature); - if (status < 0) - return status; - else - return sprintf(buf, "%d\n", temperature); -} -static DEVICE_ATTR(temp0_input, S_IRUGO, show_temperature, NULL); - - -static ssize_t show_pressure(struct device *dev, - struct device_attribute *attr, char *buf) -{ - int pressure; - int status; - struct bmp085_data *data = dev_get_drvdata(dev); - - status = bmp085_get_pressure(data, &pressure); - if (status < 0) - return status; - else - return sprintf(buf, "%d\n", pressure); -} -static DEVICE_ATTR(pressure0_input, S_IRUGO, show_pressure, NULL); - - -static struct attribute *bmp085_attributes[] = { - &dev_attr_temp0_input.attr, - &dev_attr_pressure0_input.attr, - &dev_attr_oversampling.attr, - NULL -}; - -static const struct attribute_group bmp085_attr_group = { - .attrs = bmp085_attributes, -}; - -int bmp085_detect(struct device *dev) -{ - struct bmp085_data *data = dev_get_drvdata(dev); - unsigned int id; - int ret; - - 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 void bmp085_get_of_properties(struct bmp085_data *data) -{ -#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); - - return 0; -} - -struct regmap_config bmp085_regmap_config = { - .reg_bits = 8, - .val_bits = 8 -}; -EXPORT_SYMBOL_GPL(bmp085_regmap_config); - -int bmp085_probe(struct device *dev, struct regmap *regmap, int irq) -{ - struct bmp085_data *data; - int err = 0; - - data = kzalloc(sizeof(struct bmp085_data), GFP_KERNEL); - if (!data) { - err = -ENOMEM; - goto exit; - } - - dev_set_drvdata(dev, data); - data->dev = dev; - data->regmap = regmap; - data->irq = irq; - - if (data->irq > 0) { - err = devm_request_irq(dev, data->irq, bmp085_eoc_isr, - IRQF_TRIGGER_RISING, "bmp085", - data); - if (err < 0) - goto exit_free; - } - - /* Initialize the BMP085 chip */ - 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(&dev->kobj, &bmp085_attr_group); - if (err) - goto exit_free; - - dev_info(dev, "Successfully initialized %s!\n", BMP085_NAME); - - return 0; - -exit_free: - kfree(data); -exit: - return err; -} -EXPORT_SYMBOL_GPL(bmp085_probe); - -int bmp085_remove(struct device *dev) -{ - struct bmp085_data *data = dev_get_drvdata(dev); - - sysfs_remove_group(&data->dev->kobj, &bmp085_attr_group); - kfree(data); - - return 0; -} -EXPORT_SYMBOL_GPL(bmp085_remove); - -MODULE_AUTHOR("Christoph Mair <christoph.mair@gmail.com>"); -MODULE_DESCRIPTION("BMP085 driver"); -MODULE_LICENSE("GPL"); |