i2c_armadillo2x0.c

Hermit-at-1.1.3,一款bootloader

#include <ep93xx/ioregs.h>
#include <ep93xx/regs_eth.h>
#include <target/io.h>

#include "i2c_armadillo2x0.h"
#include "board.h"

#define I2C_SDA_BIT BIT(4)
#define I2C_SCL_BIT BIT(5)

#define i2c_delay() udelay(10)

static void i2c_set_sda(void){
  IO_GPIO_PBDDR |= I2C_SDA_BIT;
  IO_GPIO_PBDR  |= I2C_SDA_BIT;
  i2c_delay();
}

static void i2c_clr_sda(void){
  IO_GPIO_PBDDR |= I2C_SDA_BIT;
  IO_GPIO_PBDR  &= ~I2C_SDA_BIT;
  i2c_delay();
}

static int i2c_read_sda(void){
  unsigned long val;
  IO_GPIO_PBDDR &= ~I2C_SDA_BIT;
  val = (IO_GPIO_PBDR & I2C_SDA_BIT);
  i2c_delay();
  return (val ? 1 : 0);
}

static void i2c_set_scl(void){
  IO_GPIO_PBDDR |= I2C_SCL_BIT;
  IO_GPIO_PBDR  |= I2C_SCL_BIT;
  i2c_delay();
}

static void i2c_clr_scl(void){
  IO_GPIO_PBDDR |= I2C_SCL_BIT;
  IO_GPIO_PBDR  &= ~I2C_SCL_BIT;
  i2c_delay();
}

static int i2c_ack(void){
  int timeout = 1000;
  IO_GPIO_PBDDR &= ~I2C_SDA_BIT;
  i2c_set_scl();
  while(timeout--){
    if(i2c_read_sda() == 0) break;
  }
  if(timeout < 0){
    hprintf("timeout acknowledge\n");
    return -1;
  }
  i2c_clr_scl();
  return 0;
}

static int i2c_read(void){
  unsigned char ch;
  unsigned char bit;
  
  int i;
  for(i=0, ch=0; i<8;i++){
    i2c_set_scl();
    bit = i2c_read_sda();
    i2c_clr_scl();

    ch |= (bit << (7-i));
  }
  return (int)ch;
}

static void i2c_write(unsigned char ch){
  unsigned char bit;
  int i;

  i2c_clr_scl();
  for(i=0; i<8; i++){
    bit = ((ch >> (7-i)) & 0x01);
    if(bit){
      i2c_set_sda();
    }else{
      i2c_clr_sda();
    }
    i2c_set_scl();
    i2c_clr_scl();
  }
}

static void i2c_start(void){
  i2c_set_sda();
  i2c_set_scl();
  i2c_clr_sda();
  i2c_clr_scl();
}

static void i2c_stop(void){
  i2c_clr_scl();
  i2c_clr_sda();
  i2c_set_scl();
  i2c_set_sda();
}

static void i2c_init(void){
  i2c_stop();
}

static int eeprom_getc(unsigned long addr){
  int ch;
  i2c_start();

  //Control
  i2c_write(0xa0);
  if(i2c_ack() == -1){
    i2c_stop();
    return -1;
  }

  //Address
  i2c_write((unsigned char)addr);
  if(i2c_ack() == -1){
    i2c_stop();
    return -1;
  }

  i2c_start();

  //Control
  i2c_write(0xa1);
  if(i2c_ack() == -1){
    i2c_stop();
    return -1;
  }

  //Data read
  ch = i2c_read();

  i2c_stop();

  return ch;
}

static int eeprom_putc(unsigned long addr, unsigned int ch){
  i2c_start();

  //Control
  i2c_write(0xa0);
  if(i2c_ack() == -1){
    i2c_stop();
    return -1;
  }

  //Address
  i2c_write((unsigned char)addr);
  if(i2c_ack() == -1){
    i2c_stop();
    return -1;
  }

  //Value
  i2c_write((unsigned char)ch);
  if(i2c_ack() == -1){
    i2c_stop();
    return -1;
  }

  i2c_stop();
  mdelay(10);

  return 0;
}

int arch_get_mac(unsigned char *mac){
  int i;
  int ch;

  i2c_init();

  for(i=0; i<6; i++){
    ch = eeprom_getc(i);
    if(ch == -1){
      return -1;
    }
    mac[i] = ch;
  }
  return 0;
}

int arch_set_mac(unsigned char *mac){
  int i;

  i2c_init();

  for(i=0; i<6; i++){
    eeprom_putc(i, mac[i]);
  }
  return 0;
}