i2c_ns9750.c

Hermit-at-1.1.3,一款bootloader

#include <arch/ioregs.h>
#include <target/io.h>

#include "board.h"

#define CMD_NOP    0x000
#define CMD_READ   0x400
#define CMD_WRITE  0x500
#define CMD_STOP   0x600
#define CMD_TXVAL  0x2000

#define IRQ_M_TX_DATA 0x300 
#define IRQ_M_RX_DATA 0x400
#define IRQ_M_CMD_ACK 0x500
#define IRQ_MASK      0xf00

static int i2c_send_cmd(unsigned long cmd){
  IO_I2C_CMD_TX_DATA = cmd;
  return 0;
}

static int i2c_wait_irq(unsigned long irq){
  unsigned long status;
  while(1){
    status = IO_I2C_STATUS_RX_DATA;
    if((status & IRQ_MASK) == irq){
      if(irq == IRQ_M_RX_DATA){
	return (int)(status & 0xff);
      }else{
	return 0;
      }
    }
  }
}

static int i2c_read(unsigned long addr)
{
  int value;

  mdelay(10);

  i2c_send_cmd(CMD_WRITE | CMD_TXVAL | addr);
  i2c_wait_irq(IRQ_M_TX_DATA);

  i2c_send_cmd(CMD_READ);
  value = i2c_wait_irq(IRQ_M_RX_DATA);

  i2c_send_cmd(CMD_STOP);
  i2c_wait_irq(IRQ_M_CMD_ACK);

  return value;
}

static int i2c_write(unsigned long addr, unsigned char c)
{
  mdelay(10);

  i2c_send_cmd(CMD_WRITE | CMD_TXVAL | addr);
  i2c_wait_irq(IRQ_M_TX_DATA);

  i2c_send_cmd(CMD_NOP | CMD_TXVAL | c);
  i2c_wait_irq(IRQ_M_TX_DATA);

  i2c_send_cmd(CMD_STOP);
  i2c_wait_irq(IRQ_M_CMD_ACK);

  return 0;
}

static void i2c_init(void){
  IO_I2C_CONFIG = 0x1f4 | 0x0200; //50Khz
  IO_I2C_MASTER_ADDR = 0xa0;
  IO_I2C_SLAVE_ADDR = 0x00;
}

static int eeprom_getc(unsigned long addr){
  return i2c_read(addr);
}

static int eeprom_putc(unsigned long addr, unsigned int ch){
  return i2c_write(addr, ch);
}

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;
}