/*
	$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");
/**
 *  @}
**/