drivers/input/misc/mpu3050/mpu-i2c.c

/*
 $License:
    Copyright (C) 2010 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/>.
  $
 */


#include <linux/delay.h>
#include <linux/i2c.h>
#include "mpu.h"
#define MPU_I2C_RETRY_ENABLE 1
#define MPU_I2C_RETRY_TIMES 10
#define MPU_I2C_DELAY_TIMES_MS 10

int sensor_i2c_write(struct i2c_adapter *i2c_adap,
		     unsigned char address,
		     unsigned int len, unsigned char const *data)
{
	struct i2c_msg msgs[1];
	int res;
	int i;

	if (NULL == data || NULL == i2c_adap)
		return -EINVAL;

	msgs[0].addr = address;
	msgs[0].flags = 0;	
	msgs[0].buf = (unsigned char *) data;
	msgs[0].len = len;

#if MPU_I2C_RETRY_ENABLE
		for (i = 0; i < MPU_I2C_RETRY_TIMES; i++) {
			res = i2c_transfer(i2c_adap, msgs, 1);
			if (res < 1) {
				printk(KERN_ERR "I2c Slave address: %x,\
				sensor_i2c_write fail,\
				retry:%d\n", address, i);
				mdelay(MPU_I2C_DELAY_TIMES_MS);
			} else
				return 0;

		}
		return res;
#else
	res = i2c_transfer(i2c_adap, msgs, 1);
	if (res < 1)
		return res;
	else
		return 0;
#endif
}

int sensor_i2c_write_register(struct i2c_adapter *i2c_adap,
			      unsigned char address,
			      unsigned char reg, unsigned char value)
{
	unsigned char data[2];

	data[0] = reg;
	data[1] = value;
	return sensor_i2c_write(i2c_adap, address, 2, data);
}

int sensor_i2c_read(struct i2c_adapter *i2c_adap,
		    unsigned char address,
		    unsigned char reg,
		    unsigned int len, unsigned char *data)
{
	struct i2c_msg msgs[2];
	int res;
	int i;

	if (NULL == data || NULL == i2c_adap)
		return -EINVAL;

	msgs[0].addr = address;
	msgs[0].flags = 0;	
	msgs[0].buf = &reg;
	msgs[0].len = 1;

	msgs[1].addr = address;
	msgs[1].flags = I2C_M_RD;
	msgs[1].buf = data;
	msgs[1].len = len;

#if MPU_I2C_RETRY_ENABLE
		for (i = 0; i < MPU_I2C_RETRY_TIMES; i++) {
			res = i2c_transfer(i2c_adap, msgs, 2);
			if (res < 2) {
				printk(KERN_ERR "I2c Slave address: %x,\
				sensor_i2c_read fail,\
				retry:%d\n", address, i);
				mdelay(MPU_I2C_DELAY_TIMES_MS);
			} else
				return 0;

		}
		return res;
#else
	res = i2c_transfer(i2c_adap, msgs, 2);
	if (res < 2)
		return res;
	else
		return 0;
#endif
}

int mpu_memory_read(struct i2c_adapter *i2c_adap,
		    unsigned char mpu_addr,
		    unsigned short mem_addr,
		    unsigned int len, unsigned char *data)
{
	unsigned char bank[2];
	unsigned char addr[2];
	unsigned char buf;

	struct i2c_msg msgs[4];
	int ret;
	int i;

	if (NULL == data || NULL == i2c_adap)
		return -EINVAL;

	bank[0] = MPUREG_BANK_SEL;
	bank[1] = mem_addr >> 8;

	addr[0] = MPUREG_MEM_START_ADDR;
	addr[1] = mem_addr & 0xFF;

	buf = MPUREG_MEM_R_W;

	
	msgs[0].addr = mpu_addr;
	msgs[0].flags = 0;
	msgs[0].buf = bank;
	msgs[0].len = sizeof(bank);

	msgs[1].addr = mpu_addr;
	msgs[1].flags = 0;
	msgs[1].buf = addr;
	msgs[1].len = sizeof(addr);

	msgs[2].addr = mpu_addr;
	msgs[2].flags = 0;
	msgs[2].buf = &buf;
	msgs[2].len = 1;

	msgs[3].addr = mpu_addr;
	msgs[3].flags = I2C_M_RD;
	msgs[3].buf = data;
	msgs[3].len = len;

#if MPU_I2C_RETRY_ENABLE
		for (i = 0; i < MPU_I2C_RETRY_TIMES; i++) {
			ret = i2c_transfer(i2c_adap, msgs, 4);
			if (ret != 4) {
				printk(KERN_ERR "I2c Slave address: %x,\
				mpu_memory_read,\
				retry:%d\n", mpu_addr, i);
				mdelay(MPU_I2C_DELAY_TIMES_MS);
			} else
				return 0;

		}
		return ret;
#else
	ret = i2c_transfer(i2c_adap, msgs, 4);
	if (ret != 4)
		return ret;
	else
		return 0;
#endif
}

int mpu_memory_write(struct i2c_adapter *i2c_adap,
		     unsigned char mpu_addr,
		     unsigned short mem_addr,
		     unsigned int len, unsigned char const *data)
{
	unsigned char bank[2];
	unsigned char addr[2];
	unsigned char buf[513];

	struct i2c_msg msgs[3];
	int ret;
	int i;

	if (NULL == data || NULL == i2c_adap)
		return -EINVAL;
	if (len >= (sizeof(buf) - 1))
		return -ENOMEM;

	bank[0] = MPUREG_BANK_SEL;
	bank[1] = mem_addr >> 8;

	addr[0] = MPUREG_MEM_START_ADDR;
	addr[1] = mem_addr & 0xFF;

	buf[0] = MPUREG_MEM_R_W;
	memcpy(buf + 1, data, len);

	
	msgs[0].addr = mpu_addr;
	msgs[0].flags = 0;
	msgs[0].buf = bank;
	msgs[0].len = sizeof(bank);

	msgs[1].addr = mpu_addr;
	msgs[1].flags = 0;
	msgs[1].buf = addr;
	msgs[1].len = sizeof(addr);

	msgs[2].addr = mpu_addr;
	msgs[2].flags = 0;
	msgs[2].buf = (unsigned char *) buf;
	msgs[2].len = len + 1;

#if MPU_I2C_RETRY_ENABLE
		for (i = 0; i < MPU_I2C_RETRY_TIMES; i++) {
			ret = i2c_transfer(i2c_adap, msgs, 3);
			if (ret != 3) {
				printk(KERN_ERR "I2c Slave address: %x,\
				mpu_memory_write,\
				retry:%d\n", mpu_addr, i);
				mdelay(MPU_I2C_DELAY_TIMES_MS);
			} else
				return 0;

		}
		return ret;
#else
	ret = i2c_transfer(i2c_adap, msgs, 3);
	if (ret != 3)
		return ret;
	else
		return 0;
#endif
}