drivers/input/touchscreen/focaltech_touch/focaltech_i2c.c

/*
 *
 * FocalTech TouchScreen driver.
 *
 * Copyright (c) 2010-2016, FocalTech Systems, Ltd., all rights reserved.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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.
 *
 */

/************************************************************************
*
* File Name: focaltech_i2c.c
*
*    Author: fupeipei
*
*   Created: 2016-08-04
*
*  Abstract: i2c communication with TP
*
*   Version: v1.0
*
* Revision History:
*        v1.0:
*            First release. By fupeipei 2016-08-04
************************************************************************/

/*****************************************************************************
* Included header files
*****************************************************************************/
#include "focaltech_core.h"

/*****************************************************************************
* Private constant and macro definitions using #define
*****************************************************************************/

/*****************************************************************************
* Private enumerations, structures and unions using typedef
*****************************************************************************/

/*****************************************************************************
* Static variables
*****************************************************************************/
static DEFINE_MUTEX(i2c_rw_access);

/*****************************************************************************
* Global variable or extern global variabls/functions
*****************************************************************************/

/*****************************************************************************
* Static function prototypes
*****************************************************************************/

/*****************************************************************************
* functions body
*****************************************************************************/

/************************************************************************
* Name: fts_i2c_read
* Brief: i2c read
* Input: i2c info, write buf, write len, read buf, read len
* Output: get data in the 3rd buf
* Return: fail <0
***********************************************************************/
int fts_i2c_read(struct i2c_client *client, char *writebuf, int writelen,
		 char *readbuf, int readlen)
{
	int ret = 0;

	mutex_lock(&i2c_rw_access);

	if (readlen > 0) {
		if (writelen > 0) {
			struct i2c_msg msgs[] = {
				{
				 .addr = client->addr,
				 .flags = 0,
				 .len = writelen,
				 .buf = writebuf,
				 },
				{
				 .addr = client->addr,
				 .flags = I2C_M_RD,
				 .len = readlen,
				 .buf = readbuf,
				 },
			};
			ret = i2c_transfer(client->adapter, msgs, 2);
			if (ret < 0) {
				FTS_ERROR("[IIC]: i2c_transfer(write)"
					"error,ret=%d!!", ret);
			}
		} else {
			struct i2c_msg msgs[] = {
				{
				 .addr = client->addr,
				 .flags = I2C_M_RD,
				 .len = readlen,
				 .buf = readbuf,
				 },
			};
			ret = i2c_transfer(client->adapter, msgs, 1);
			if (ret < 0) {
				FTS_ERROR("[IIC]: i2c_transfer(read)"
					"error, ret=%d!!", ret);
			}
		}
	}

	mutex_unlock(&i2c_rw_access);
	return ret;
}

/************************************************************************
* Name: fts_i2c_write
* Brief: i2c write
* Input: i2c info, write buf, write len
* Output: no
* Return: fail <0
***********************************************************************/
int fts_i2c_write(struct i2c_client *client, char *writebuf, int writelen)
{
	int ret = 0;

	mutex_lock(&i2c_rw_access);
	if (writelen > 0) {
		struct i2c_msg msgs[] = {
			{
			 .addr = client->addr,
			 .flags = 0,
			 .len = writelen,
			 .buf = writebuf,
			 },
		};
		ret = i2c_transfer(client->adapter, msgs, 1);
		if (ret < 0) {
			FTS_ERROR("%s: i2c_transfer(write) error, ret=%d",
				  __func__, ret);
		}
	}
	mutex_unlock(&i2c_rw_access);

	return ret;
}

/************************************************************************
* Name: fts_i2c_write_reg
* Brief: write register
* Input: i2c info, reg address, reg value
* Output: no
* Return: fail <0
***********************************************************************/
int fts_i2c_write_reg(struct i2c_client *client, u8 regaddr, u8 regvalue)
{
	u8 buf[2] = { 0 };

	buf[0] = regaddr;
	buf[1] = regvalue;
	return fts_i2c_write(client, buf, sizeof(buf));
}

/************************************************************************
* Name: fts_i2c_read_reg
* Brief: read register
* Input: i2c info, reg address, reg value
* Output: get reg value
* Return: fail <0
***********************************************************************/
int fts_i2c_read_reg(struct i2c_client *client, u8 regaddr, u8 *regvalue)
{
	return fts_i2c_read(client, &regaddr, 1, regvalue, 1);
}

/************************************************************************
* Name: fts_i2c_init
* Brief: fts i2c init
* Input:
* Output:
* Return:
***********************************************************************/
int fts_i2c_init(void)
{
	FTS_FUNC_ENTER();

	FTS_FUNC_EXIT();
	return 0;
}

/************************************************************************
* Name: fts_i2c_exit
* Brief: fts i2c exit
* Input:
* Output:
* Return:
***********************************************************************/
int fts_i2c_exit(void)
{
	FTS_FUNC_ENTER();

	FTS_FUNC_EXIT();
	return 0;
}