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kernel/linux-imx6_3.14.28/arch/mips/jazz/reset.c 1009 Bytes
6b13f685e   김민수   BSP 최초 추가
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  /*
   * Reset a Jazz machine.
   *
   * We don't trust the firmware so we do it the classic way by poking and
   * stabbing at the keyboard controller ...
   */
  #include <linux/jiffies.h>
  #include <asm/jazz.h>
  
  #define KBD_STAT_IBF		0x02	/* Keyboard input buffer full */
  
  static void jazz_write_output(unsigned char val)
  {
  	int status;
  
  	do {
  		status = jazz_kh->command;
  	} while (status & KBD_STAT_IBF);
  	jazz_kh->data = val;
  }
  
  static void jazz_write_command(unsigned char val)
  {
  	int status;
  
  	do {
  		status = jazz_kh->command;
  	} while (status & KBD_STAT_IBF);
  	jazz_kh->command = val;
  }
  
  static unsigned char jazz_read_status(void)
  {
  	return jazz_kh->command;
  }
  
  static inline void kb_wait(void)
  {
  	unsigned long start = jiffies;
  	unsigned long timeout = start + HZ/2;
  
  	do {
  		if (! (jazz_read_status() & 0x02))
  			return;
  	} while (time_before_eq(jiffies, timeout));
  }
  
  void jazz_machine_restart(char *command)
  {
  	while(1) {
  		kb_wait();
  		jazz_write_command(0xd1);
  		kb_wait();
  		jazz_write_output(0x00);
  	}
  }