Re: [PATCH 11/11] misc: Add slave driver for bma085 pressure sensor

[Jonathan Cameron <jic23@cam.ac.uk>]

Hang on, so your motion processing unit takes in a pressure sensor?
Interesting....

Manuel, am I imagining things or did you have a driver for one of these?

Happy to take barometers in IIO.
> Signed-off-by: Nathan Royer <nroyer@invensense.com>
> ---
>  drivers/misc/inv_mpu/Kconfig           |    1 +
>  drivers/misc/inv_mpu/Makefile          |    1 +
>  drivers/misc/inv_mpu/pressure/Kconfig  |   20 ++
>  drivers/misc/inv_mpu/pressure/Makefile |    8 +
>  drivers/misc/inv_mpu/pressure/bma085.c |  367 ++++++++++++++++++++++++++++++++
>  5 files changed, 397 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/misc/inv_mpu/pressure/Kconfig
>  create mode 100644 drivers/misc/inv_mpu/pressure/Makefile
>  create mode 100644 drivers/misc/inv_mpu/pressure/bma085.c
> 
> diff --git a/drivers/misc/inv_mpu/Kconfig b/drivers/misc/inv_mpu/Kconfig
> index 7d9f2c3..ea7d754 100644
> --- a/drivers/misc/inv_mpu/Kconfig
> +++ b/drivers/misc/inv_mpu/Kconfig
> @@ -57,5 +57,6 @@ endchoice
>  
>  source "drivers/misc/inv_mpu/accel/Kconfig"
>  source "drivers/misc/inv_mpu/compass/Kconfig"
> +source "drivers/misc/inv_mpu/pressure/Kconfig"
>  
>  endif #INV_SENSORS
> diff --git a/drivers/misc/inv_mpu/Makefile b/drivers/misc/inv_mpu/Makefile
> index dc77a1b..506b8f5 100644
> --- a/drivers/misc/inv_mpu/Makefile
> +++ b/drivers/misc/inv_mpu/Makefile
> @@ -18,3 +18,4 @@ EXTRA_CFLAGS += -Idrivers/misc/inv_mpu
>  
>  obj-y			+= accel/
>  obj-y			+= compass/
> +obj-y			+= pressure/
> diff --git a/drivers/misc/inv_mpu/pressure/Kconfig b/drivers/misc/inv_mpu/pressure/Kconfig
> new file mode 100644
> index 0000000..f1c021e
> --- /dev/null
> +++ b/drivers/misc/inv_mpu/pressure/Kconfig
> @@ -0,0 +1,20 @@
> +menuconfig: INV_SENSORS_PRESSURE
> +	bool "Pressure Sensor Slaves"
> +	depends on INV_SENSORS
> +	default y
> +	help
> +	  Select y to see a list of supported pressure sensors that can be
> +	  integrated with the MPUxxxx set of motion processors.
> +
> +if INV_SENSORS_PRESSURE
> +
> +config MPU_SENSORS_BMA085
> +	tristate "Bosch BMA085"
> +	help
> +	  This enables support for the Bosch bma085 pressure sensor
> +	  This support is for integration with the MPU3050 or MPU6050 gyroscope
> +          device driver.  Only one accelerometer can be registered at a time.
> +	  Specifying more that one accelerometer in the board file will result
> +	  in runtime errors.
That's a seriously weird message for a pressure sensor...
> +
> +endif
> diff --git a/drivers/misc/inv_mpu/pressure/Makefile b/drivers/misc/inv_mpu/pressure/Makefile
> new file mode 100644
> index 0000000..595923d
> --- /dev/null
> +++ b/drivers/misc/inv_mpu/pressure/Makefile
> @@ -0,0 +1,8 @@
> +#
> +# Pressure Slaves to MPUxxxx
> +#
> +obj-$(CONFIG_MPU_SENSORS_BMA085) += inv_mpu_bma085.o
> +inv_mpu_bma085-objs +=	bma085.o
> +
> +EXTRA_CFLAGS += -Idrivers/misc/inv_mpu
> +EXTRA_CFLAGS += -D__C99_DESIGNATED_INITIALIZER
> diff --git a/drivers/misc/inv_mpu/pressure/bma085.c b/drivers/misc/inv_mpu/pressure/bma085.c
> new file mode 100644
> index 0000000..696d2b6
> --- /dev/null
> +++ b/drivers/misc/inv_mpu/pressure/bma085.c
> @@ -0,0 +1,367 @@
> +/*
> +	$License:
> +	Copyright (C) 2011 InvenSense Corporation, All Rights Reserved.
> +
> +	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, see <http://www.gnu.org/licenses/>.
> +	$
> + */
> +
> +/**
> + *  @defgroup   ACCELDL (Motion Library - Pressure Driver Layer)
> + *  @brief      Provides the interface to setup and handle a pressure
> + *              connected to the secondary I2C interface of the gyroscope.
> + *
> + *  @{
> + *      @file   bma085.c
> + *      @brief  Pressure setup and handling methods.
> + */
> +
> +/* ------------------ */
> +/* - Include Files. - */
> +/* ------------------ */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include "mpu-dev.h"
> +
> +#include <linux/mpu.h>
> +#include "mlsl.h"
> +#include "log.h"
> +
> +/*
> + * this structure holds all device specific calibration parameters
> + */
> +struct bmp085_calibration_param_t {
> +	short ac1;
> +	short ac2;
> +	short ac3;
> +	unsigned short ac4;
> +	unsigned short ac5;
> +	unsigned short ac6;
> +	short b1;
> +	short b2;
> +	short mb;
> +	short mc;
> +	short md;
> +	long param_b5;
> +};
> +
> +struct bmp085_calibration_param_t cal_param;
> +
> +#define PRESSURE_BMA085_PARAM_MG      3038        /* calibration parameter */
> +#define PRESSURE_BMA085_PARAM_MH     -7357        /* calibration parameter */
> +#define PRESSURE_BMA085_PARAM_MI      3791        /* calibration parameter */
> +
> +/*********************************************
> + *    Pressure Initialization Functions
> + *********************************************/
> +
> +static int bma085_suspend(void *mlsl_handle,
> +			  struct ext_slave_descr *slave,
> +			  struct ext_slave_platform_data *pdata)
> +{
> +	int result = INV_SUCCESS;
> +	return result;
> +}
> +
> +#define PRESSURE_BMA085_PROM_START_ADDR  (0xAA)
> +#define PRESSURE_BMA085_PROM_DATA_LEN    (22)
> +#define PRESSURE_BMP085_CTRL_MEAS_REG    (0xF4)
> +/* temperature measurent */
> +#define PRESSURE_BMP085_T_MEAS           (0x2E)
> +/* pressure measurement; oversampling_setting */
> +#define PRESSURE_BMP085_P_MEAS_OSS_0     (0x34)
> +#define PRESSURE_BMP085_P_MEAS_OSS_1     (0x74)
> +#define PRESSURE_BMP085_P_MEAS_OSS_2     (0xB4)
> +#define PRESSURE_BMP085_P_MEAS_OSS_3     (0xF4)
> +#define PRESSURE_BMP085_ADC_OUT_MSB_REG  (0xF6)
> +#define PRESSURE_BMP085_ADC_OUT_LSB_REG  (0xF7)
> +
> +static int bma085_resume(void *mlsl_handle,
> +			 struct ext_slave_descr *slave,
> +			 struct ext_slave_platform_data *pdata)
> +{
> +	int result;
> +	unsigned char data[PRESSURE_BMA085_PROM_DATA_LEN];
> +
> +	result =
> +	    inv_serial_read(mlsl_handle, pdata->address,
> +			   PRESSURE_BMA085_PROM_START_ADDR,
> +			   PRESSURE_BMA085_PROM_DATA_LEN, data);
> +	if (result) {
> +		LOG_RESULT_LOCATION(result);
> +		return result;
> +	}
> +
> +	/* parameters AC1-AC6 */
> +	cal_param.ac1 = (data[0] << 8) | data[1];
> +	cal_param.ac2 = (data[2] << 8) | data[3];
> +	cal_param.ac3 = (data[4] << 8) | data[5];
> +	cal_param.ac4 = (data[6] << 8) | data[7];
> +	cal_param.ac5 = (data[8] << 8) | data[9];
> +	cal_param.ac6 = (data[10] << 8) | data[11];
> +
> +	/* parameters B1,B2 */
> +	cal_param.b1 = (data[12] << 8) | data[13];
> +	cal_param.b2 = (data[14] << 8) | data[15];
> +
> +	/* parameters MB,MC,MD */
> +	cal_param.mb = (data[16] << 8) | data[17];
> +	cal_param.mc = (data[18] << 8) | data[19];
> +	cal_param.md = (data[20] << 8) | data[21];
> +
> +	return result;
> +}
> +
> +static int bma085_read(void *mlsl_handle,
> +		       struct ext_slave_descr *slave,
> +		       struct ext_slave_platform_data *pdata,
> +		       unsigned char *data)
> +{
> +	int result;
> +	long pressure, x1, x2, x3, b3, b6;
> +	unsigned long b4, b7;
> +	unsigned long up;
> +	unsigned short ut;
> +	short oversampling_setting = 0;
> +	short temperature;
> +	long divisor;
> +
> +	/* get temprature */
> +	result = inv_serial_single_write(mlsl_handle, pdata->address,
> +				       PRESSURE_BMP085_CTRL_MEAS_REG,
> +				       PRESSURE_BMP085_T_MEAS);
> +	msleep(5);
> +	result =
> +	    inv_serial_read(mlsl_handle, pdata->address,
> +			   PRESSURE_BMP085_ADC_OUT_MSB_REG, 2,
> +			   (unsigned char *)data);
> +	if (result) {
> +		LOG_RESULT_LOCATION(result);
> +		return result;
> +	}
> +	ut = (data[0] << 8) | data[1];
> +
> +	x1 = (((long) ut - (long)cal_param.ac6) * (long)cal_param.ac5) >> 15;
> +	divisor = x1 + cal_param.md;
> +	if (!divisor)
> +		return INV_ERROR_DIVIDE_BY_ZERO;
> +
> +	x2 = ((long)cal_param.mc << 11) / (x1 + cal_param.md);
> +	cal_param.param_b5 = x1 + x2;
> +	/* temperature in 0.1 degree C */
> +	temperature = (short)((cal_param.param_b5 + 8) >> 4);
> +
> +	/* get pressure */
> +	result = inv_serial_single_write(mlsl_handle, pdata->address,
> +				       PRESSURE_BMP085_CTRL_MEAS_REG,
> +				       PRESSURE_BMP085_P_MEAS_OSS_0);
> +	msleep(5);
> +	result =
> +	    inv_serial_read(mlsl_handle, pdata->address,
> +			   PRESSURE_BMP085_ADC_OUT_MSB_REG, 2,
> +			   (unsigned char *)data);
> +	if (result) {
> +		LOG_RESULT_LOCATION(result);
> +		return result;
> +	}
> +	up = (((unsigned long) data[0] << 8) | ((unsigned long) data[1]));
> +
> +	b6 = cal_param.param_b5 - 4000;
> +	/* calculate B3 */
> +	x1 = (b6*b6) >> 12;
> +	x1 *= cal_param.b2;
> +	x1 >>= 11;
> +
> +	x2 = (cal_param.ac2*b6);
> +	x2 >>= 11;
> +
> +	x3 = x1 + x2;
> +
> +	b3 = (((((long)cal_param.ac1) * 4 + x3)
> +	    << oversampling_setting) + 2) >> 2;
> +
> +	/* calculate B4 */
> +	x1 = (cal_param.ac3 * b6) >> 13;
> +	x2 = (cal_param.b1 * ((b6*b6) >> 12)) >> 16;
> +	x3 = ((x1 + x2) + 2) >> 2;
> +	b4 = (cal_param.ac4 * (unsigned long) (x3 + 32768)) >> 15;
> +	if (!b4)
> +		return INV_ERROR;
> +
> +	b7 = ((unsigned long)(up - b3) * (50000>>oversampling_setting));
> +	if (b7 < 0x80000000)
> +		pressure = (b7 << 1) / b4;
> +	else
> +		pressure = (b7 / b4) << 1;
> +
> +	x1 = pressure >> 8;
> +	x1 *= x1;
> +	x1 = (x1 * PRESSURE_BMA085_PARAM_MG) >> 16;
> +	x2 = (pressure * PRESSURE_BMA085_PARAM_MH) >> 16;
> +	/* pressure in Pa */
> +	pressure += (x1 + x2 + PRESSURE_BMA085_PARAM_MI) >> 4;
> +
> +	data[0] = (unsigned char)(pressure >> 16);
> +	data[1] = (unsigned char)(pressure >> 8);
> +	data[2] = (unsigned char)(pressure & 0xFF);
> +
> +	return result;
> +}
> +
> +static struct ext_slave_descr bma085_descr = {
> +	.init             = NULL,
> +	.exit             = NULL,
> +	.suspend          = bma085_suspend,
> +	.resume           = bma085_resume,
> +	.read             = bma085_read,
> +	.config           = NULL,
> +	.get_config       = NULL,
> +	.name             = "bma085",
> +	.type             = EXT_SLAVE_TYPE_PRESSURE,
> +	.id               = PRESSURE_ID_BMA085,
> +	.read_reg         = 0xF6,
> +	.read_len         = 3,
> +	.endian           = EXT_SLAVE_BIG_ENDIAN,
> +	.range            = {0, 0},
> +};
> +
> +static
> +struct ext_slave_descr *bma085_get_slave_descr(void)
> +{
> +	return &bma085_descr;
> +}
> +
> +/* Platform data for the MPU */
> +struct bma085_mod_private_data {
> +	struct i2c_client *client;
> +	struct ext_slave_platform_data *pdata;
> +};
> +
> +static unsigned short normal_i2c[] = { I2C_CLIENT_END };
> +
> +static int bma085_mod_probe(struct i2c_client *client,
> +			   const struct i2c_device_id *devid)
> +{
> +	struct ext_slave_platform_data *pdata;
> +	struct bma085_mod_private_data *private_data;
> +	int result = 0;
> +
> +	dev_info(&client->adapter->dev, "%s: %s\n", __func__, devid->name);
> +
> +	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
> +		result = -ENODEV;
> +		goto out_no_free;
> +	}
> +
> +	pdata = client->dev.platform_data;
> +	if (!pdata) {
> +		dev_err(&client->adapter->dev,
> +			"Missing platform data for slave %s\n", devid->name);
> +		result = -EFAULT;
> +		goto out_no_free;
> +	}
> +
> +	private_data = kzalloc(sizeof(*private_data), GFP_KERNEL);
> +	if (!private_data) {
> +		result = -ENOMEM;
> +		goto out_no_free;
> +	}
> +
> +	i2c_set_clientdata(client, private_data);
> +	private_data->client = client;
> +	private_data->pdata = pdata;
> +
> +	result = inv_mpu_register_slave(THIS_MODULE, client, pdata,
> +					bma085_get_slave_descr);
> +	if (result) {
> +		dev_err(&client->adapter->dev,
> +			"Slave registration failed: %s, %d\n",
> +			devid->name, result);
> +		goto out_free_memory;
> +	}
> +
> +	return result;
> +
> +out_free_memory:
> +	kfree(private_data);
> +out_no_free:
> +	dev_err(&client->adapter->dev, "%s failed %d\n", __func__, result);
> +	return result;
> +
> +}
> +
> +static int bma085_mod_remove(struct i2c_client *client)
> +{
> +	struct bma085_mod_private_data *private_data =
> +		i2c_get_clientdata(client);
> +
> +	dev_dbg(&client->adapter->dev, "%s\n", __func__);
> +
> +	inv_mpu_unregister_slave(client, private_data->pdata,
> +				bma085_get_slave_descr);
> +
> +	kfree(private_data);
> +	return 0;
> +}
> +
> +static const struct i2c_device_id bma085_mod_id[] = {
> +	{ "bma085", PRESSURE_ID_BMA085 },
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, bma085_mod_id);
> +
> +static struct i2c_driver bma085_mod_driver = {
> +	.class = I2C_CLASS_HWMON,
> +	.probe = bma085_mod_probe,
> +	.remove = bma085_mod_remove,
> +	.id_table = bma085_mod_id,
> +	.driver = {
> +		   .owner = THIS_MODULE,
> +		   .name = "bma085_mod",
> +		   },
> +	.address_list = normal_i2c,
> +};
> +
> +static int __init bma085_mod_init(void)
> +{
> +	int res = i2c_add_driver(&bma085_mod_driver);
> +	pr_info("%s: Probe name %s\n", __func__, "bma085_mod");
> +	if (res)
> +		pr_err("%s failed\n", __func__);
> +	return res;
> +}
> +
> +static void __exit bma085_mod_exit(void)
> +{
> +	pr_info("%s\n", __func__);
> +	i2c_del_driver(&bma085_mod_driver);
> +}
> +
> +module_init(bma085_mod_init);
> +module_exit(bma085_mod_exit);
> +
> +MODULE_AUTHOR("Invensense Corporation");
> +MODULE_DESCRIPTION("Driver to integrate BMA085 sensor with the MPU");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("bma085_mod");
> +/**
> + *  @}
> +**/