vcodec_sdk.c

视频COEDC SAA7113 7121 SDK和应用程序

/*****************************************************************************************************************************************
File Name: vcodec_SDK.c
Author: Xue, Zhenwu
Date: October, 19th, 2007
Revision: 1.0
Description: SDK of video codec for the yth project.
******************************************************************************************************************************************/

#include <unistd.h>      
#include <fcntl.h>       
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>       
#include <linux/ioctl.h>
#include <asm-arm/ioctl.h>
#include <sys/ioctl.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/config.h>
#include <linux/slab.h>
#include <linux/errno.h>
#define VDECODER_WADDR 0x4A
#define VDECODER_RADDR 0x4B
#define VENCODER_WADDR 0x88

static int I2C;                      /*Device ID of the I2C bus*/
int init_I2C();               /*Initialize the I2C bus*/
int write_7113(unsigned char address, unsigned char value);         /*Write a value into SAA7113H's register*/
unsigned char read_7113(unsigned char address);                     /*Read SAA7113H's register*/
int write_7121(unsigned char address, unsigned char value);         /*Write a value into SAA7121's register*/
unsigned char read_7121(unsigned char address);                    /*Read SAA7121's register*/
int release_I2C();            /*Release the I2C bus*/

/*********************************************************************************************************************************
Function: init_I2C
Description: open the i2c device
**********************************************************************************************************************************/
int init_I2C(){
  I2C = open("/dev/i2c/0", O_RDWR);
  if(I2C<0){
    printf("Error: Unable to open I2C device!\n");
    return -1;
  }else{
    return 0;
  }
}

/************************************************************************************************************************************
Function: write_7113
Description: Write a value into SAA7113H's register
************************************************************************************************************************************/
int write_7113(unsigned char address, unsigned char value){
  unsigned char buf[2];
  int ret;
  unsigned char vv;
  int i;
  int count = 0;

  while(count<=20){
    buf[0] = address;
    buf[1] = value;
    ioctl(I2C, I2C_TENBIT, 0);
    ioctl(I2C, I2C_SLAVE_FORCE, VDECODER_WADDR>>1);
    ret=write(I2C, buf, 2);
    while((ret=write(I2C, buf, 2))<2);
    printf("Info: Write %d bytes into SAA7113 at 0x%02X.\n", ret, address);

    vv = read_7113(address);
    if(vv==value){
      break;
    }

    i = 1000;
    while(i--);

    count++;
  }

  if(vv!=value){
    printf("Error when writing SAA7113 at 0x%02X!\n", address);
  }

  return ret;
}

/*************************************************************************************************************************************
Function: read_7113
Description: Read SAA7113H's register
**************************************************************************************************************************************/
unsigned char read_7113(unsigned char address){
  unsigned char buf[2];
  int ret;

  buf[0] = address;
  ret = ioctl(I2C, I2C_TENBIT, 0);
  ret = ioctl(I2C, I2C_SLAVE_FORCE, VDECODER_RADDR>>1);
  ret = write(I2C, &address, 1);
  while((ret = write(I2C, &address, 1))<1);
  ret = read(I2C, &buf[1], 1);
  while((ret = read(I2C, &buf[1], 1))<1);

  return buf[1];
}

/************************************************************************************************************************************
Function: write_7121
Description: Write a value into SAA7121's register
************************************************************************************************************************************/
int write_7121(unsigned char address, unsigned char value){
  unsigned char buf[2];
  int ret;

  buf[0] = address;
  buf[1] = value;
  ioctl(I2C, I2C_TENBIT, 0);
  ioctl(I2C, I2C_SLAVE_FORCE, VENCODER_WADDR>>1);
  ret = write(I2C, buf, 2);
  while((ret = write(I2C, buf, 2))<2);
  //printf("Info: Write %d bytes into SAA7121 at 0x%02X.\n", ret, address);

  return 0;
}

/*************************************************************************************************************************************
Function: read_7121
Description: Read SAA7121's register
**************************************************************************************************************************************/
unsigned char read_7121(unsigned char address){
  unsigned char buf[2];
  int ret;

  buf[0] = address;
  ret = ioctl(I2C, I2C_TENBIT, 0);
  ret = ioctl(I2C, I2C_SLAVE_FORCE, VENCODER_WADDR>>1);
  ret = write(I2C, &address, 1);
  if(ret<0){
    printf("Error when sending SAA7121's register address!\n");
  }
  ret = read(I2C, &buf[1], 1);
  if(ret<0){
    printf("Error when reading SAA7121!\n");
  }

  return buf[1];
}

/************************************************************************************************************************************
Function: release_I2C
Description: release the I2C device
************************************************************************************************************************************/
int release_I2C(){
  close(I2C);
  return 0;
}