Messages in this thread Patch in this message | | | From | Eric Andersson <> | Subject | [PATCHv2 1/3] misc: clean up bmp085 driver | Date | Tue, 6 Mar 2012 22:08:02 +0100 |
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This patch includes various cleaning of the bmp085 driver including: - Addition of platform_data and header file - Implement pm functions - Whitespaces and alignment fixes - Minor typos - Consistency fixes
Reviewed-by: Stefan Nilsson <stefan.nilsson@unixphere.com> Signed-off-by: Eric Andersson <eric.andersson@unixphere.com> --- drivers/misc/bmp085.c | 178 ++++++++++++++++++++++++++++---------------- include/linux/i2c/bmp085.h | 43 +++++++++++ 2 files changed, 158 insertions(+), 63 deletions(-) create mode 100644 include/linux/i2c/bmp085.h
diff --git a/drivers/misc/bmp085.c b/drivers/misc/bmp085.c index b29a2be..5978094 100644 --- a/drivers/misc/bmp085.c +++ b/drivers/misc/bmp085.c @@ -1,4 +1,6 @@ /* 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 digital barometric pressure and temperature sensor from Bosch Sensortec. The datasheet @@ -42,13 +44,13 @@ 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/i2c/bmp085.h> #define BMP085_I2C_ADDRESS 0x77 #define BMP085_CHIP_ID 0x55 @@ -56,7 +58,6 @@ #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; - u32 last_temp_measurement; - s32 b6; /* calculated temperature correction coefficient */ + 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; + u32 last_temp_measurement; + 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; @@ -129,8 +124,8 @@ 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) { + BMP085_TEMP_MEASUREMENT); + 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 + * measurememt 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) { @@ -233,16 +230,17 @@ static s32 bmp085_get_pressure(struct bmp085_data *data, int *pressure) s32 p; int status; - /* alt least every second force an update of the ambient temperature */ - if (data->last_temp_measurement + 1*HZ < jiffies) { + /* update the ambient temperature according to the given meas. period */ + if (data->last_temp_measurement + + data->temp_measurement_period < jiffies) { 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; @@ -273,15 +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, @@ -308,12 +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, @@ -321,6 +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, @@ -336,7 +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); @@ -353,7 +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); @@ -385,43 +387,58 @@ 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); + struct bmp085_platform_data *pdata = client->dev.platform_data; + 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->oversampling_setting = 3; + data->temp_measurement_period = + pdata ? (pdata->temp_measurement_period/1000)*HZ : 1*HZ; + data->oversampling_setting = pdata ? pdata->default_oversampling : 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; + struct bmp085_platform_data *pdata = client->dev.platform_data; + u8 chip_id = (pdata && pdata->chip_id) ? pdata->chip_id : + BMP085_CHIP_ID; int err = 0; + if (pdata && pdata->init_hw) { + err = pdata->init_hw(&client->dev); + if (err) { + dev_err(&client->dev, "%s: init_hw failed!\n", + BMP085_NAME); + return err; + } + } + data = kzalloc(sizeof(struct bmp085_data), GFP_KERNEL); if (!data) { err = -ENOMEM; goto exit; } - /* default settings after POR */ - data->oversampling_setting = 0x00; - i2c_set_clientdata(client, data); + if (i2c_smbus_read_byte_data(client, BMP085_CHIP_ID_REG) != chip_id) { + dev_err(&client->dev, "%s: chip_id failed!\n", BMP085_NAME); + err = -ENODEV; + goto exit_free; + } + /* Initialize the BMP085 chip */ err = bmp085_init_client(client); - if (err != 0) + if (err < 0) goto exit_free; /* Register sysfs hooks */ @@ -429,22 +446,57 @@ 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, "Succesfully initialized bmp085!\n"); + return 0; exit_free: kfree(data); exit: + if (pdata && pdata->deinit_hw) + pdata->deinit_hw(&client->dev); return err; } static int __devexit bmp085_remove(struct i2c_client *client) { + struct bmp085_data *data = i2c_get_clientdata(client); + struct bmp085_platform_data *pdata = client->dev.platform_data; + sysfs_remove_group(&client->dev.kobj, &bmp085_attr_group); - kfree(i2c_get_clientdata(client)); + + if (pdata && pdata->deinit_hw) + pdata->deinit_hw(&client->dev); + + kfree(data); + return 0; } +#ifdef CONFIG_PM +static int bmp085_suspend(struct device *dev) +{ + struct bmp085_platform_data *pdata = dev->platform_data; + + if (pdata && pdata->deinit_hw) + pdata->deinit_hw(dev); + + return 0; +} + +static int bmp085_resume(struct device *dev) +{ + struct bmp085_platform_data *pdata = dev->platform_data; + + if (pdata && pdata->init_hw) + return pdata->init_hw(dev); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(bmp085_pm_ops, bmp085_suspend, + bmp085_resume); + static const struct i2c_device_id bmp085_id[] = { { "bmp085", 0 }, { } @@ -454,7 +506,8 @@ MODULE_DEVICE_TABLE(i2c, bmp085_id); static struct i2c_driver bmp085_driver = { .driver = { .owner = THIS_MODULE, - .name = "bmp085" + .name = "bmp085", + .pm = &bmp085_pm_ops, }, .id_table = bmp085_id, .probe = bmp085_probe, @@ -474,7 +527,6 @@ static void __exit bmp085_exit(void) i2c_del_driver(&bmp085_driver); } - MODULE_AUTHOR("Christoph Mair <christoph.mair@gmail.com"); MODULE_DESCRIPTION("BMP085 driver"); MODULE_LICENSE("GPL"); diff --git a/include/linux/i2c/bmp085.h b/include/linux/i2c/bmp085.h new file mode 100644 index 0000000..e6fc752 --- /dev/null +++ b/include/linux/i2c/bmp085.h @@ -0,0 +1,43 @@ +/* + * Copyright (c) 2012 Bosch Sensortec GmbH + * Copyright (c) 2012 Unixphere AB + * + * 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. + */ + +#ifndef _BMP085_H +#define _BMP085_H + +#define BMP085_NAME "bmp085" + +/** + * struct bmp085_platform_data - represents platform data for the bmp085 driver + * @chip_id: Configurable chip id for non-default chip revisions + * @default_oversampling: Default oversampling value to be used at startup, + * value range is 0-3 with rising sensitivity. + * @temp_measurement_period: Temperature measurement period (milliseconds), set + * to zero if unsure. + * @init_hw: Callback for hw specific startup + * @deinit_hw: Callback for hw specific shutdown + */ +struct bmp085_platform_data { + u8 chip_id; + u8 default_oversampling; + u32 temp_measurement_period; + int (*init_hw)(struct device *dev); + void (*deinit_hw)(struct device *dev); +}; + +#endif -- 1.7.3.4
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