/*
   * (C) Copyright 2006
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include <common.h>
  #include <mpc5xxx.h>
  
  /* For the V38B board the pin is GPIO_PSC_6 */
  #define GPIO_PIN	GPIO_PSC6_0
  
  #define NO_ERROR	0
  #define ERR_NO_NUMBER	1
  #define ERR_BAD_NUMBER	2
  
  static int is_high(void);
  static int check_device(void);
  static void io_out(int value);
  static void io_input(void);
  static void io_output(void);
  static void init_gpio(void);
  static void read_byte(unsigned char *data);
  static void write_byte(unsigned char command);
  
  void read_2501_memory(unsigned char *psernum, unsigned char *perr);
  void board_get_enetaddr(uchar *enetaddr);
  
  
  static int is_high()
  {
  	return (*((vu_long *) MPC5XXX_WU_GPIO_DATA_I) & GPIO_PIN);
  }
  
  static void io_out(int value)
  {
  	if (value)
  		*((vu_long *) MPC5XXX_WU_GPIO_DATA_O) |= GPIO_PIN;
  	else
  		*((vu_long *) MPC5XXX_WU_GPIO_DATA_O) &= ~GPIO_PIN;
  }
  
  static void io_input()
  {
  	*((vu_long *) MPC5XXX_WU_GPIO_DIR) &= ~GPIO_PIN;
  	udelay(3);	/* allow input to settle */
  }
  
  static void io_output()
  {
  	*((vu_long *) MPC5XXX_WU_GPIO_DIR) |= GPIO_PIN;
  }
  
  static void init_gpio()
  {
  	*((vu_long *) MPC5XXX_WU_GPIO_ENABLE) |= GPIO_PIN;	/* Enable appropriate pin */
  }
  
  void read_2501_memory(unsigned char *psernum, unsigned char *perr)
  {
  #define NBYTES 28
  	unsigned char crcval, i;
  	unsigned char buf[NBYTES];
  
  	*perr = 0;
  	crcval = 0;
  
  	for (i = 0; i < NBYTES; i++)
  		buf[i] = 0;
  
  	if (!check_device())
  		*perr = ERR_NO_NUMBER;
  	else {
  		*perr = NO_ERROR;
  		write_byte(0xCC);		/* skip ROM (0xCC) */
  		write_byte(0xF0);		/* Read memory command 0xF0 */
  		write_byte(0x00);		/* Address TA1=0, TA2=0 */
  		write_byte(0x00);
  		read_byte(&crcval);		/* Read CRC of address and command */
  
  		for (i = 0; i < NBYTES; i++)
  			read_byte(&buf[i]);
  	}
  	if (strncmp((const char *) &buf[11], "MAREL IEEE 802.3", 16)) {
  		*perr = ERR_BAD_NUMBER;
  		psernum[0] = 0x00;
  		psernum[1] = 0xE0;
  		psernum[2] = 0xEE;
  		psernum[3] = 0xFF;
  		psernum[4] = 0xFF;
  		psernum[5] = 0xFF;
  	} else {
  		psernum[0] = 0x00;
  		psernum[1] = 0xE0;
  		psernum[2] = 0xEE;
  		psernum[3] = buf[7];
  		psernum[4] = buf[6];
  		psernum[5] = buf[5];
  	}
  }
  
  static int check_device()
  {
  	int found;
  
  	io_output();
  	io_out(0);
  	udelay(500);  /* must be at least 480 us low pulse */
  
  	io_input();
  	udelay(60);
  
  	found = (is_high() == 0) ? 1 : 0;
  	udelay(500);  /* must be at least 480 us low pulse */
  
  	return found;
  }
  
  static void write_byte(unsigned char command)
  {
  	char i;
  
  	for (i = 0; i < 8; i++) {
  		/* 1 us to 15 us low pulse starts bit slot */
  		/* Start with high pulse for 3 us */
  		io_input();
  		udelay(3);
  
  		io_out(0);
  		io_output();
  		udelay(3);
  
  		if (command & 0x01) {
  			/* 60 us high for 1-bit */
  			io_input();
  			udelay(60);
  		} else
  			/* 60 us low for 0-bit */
  			udelay(60);
  		/*  Leave pin as input */
  		io_input();
  
  		command = command >> 1;
  	}
  }
  
  static void read_byte(unsigned char *data)
  {
  	unsigned char i, rdat = 0;
  
  	for (i = 0; i < 8; i++) {
  		/* read one bit from one-wire device */
  
  		/* 1 - 15 us low starts bit slot */
  		io_out(0);
  		io_output();
  		udelay(0);
  
  		/* allow line to be pulled high */
  		io_input();
  
  		/* delay 10 us */
  		udelay(10);
  
  		/* now sample input status */
  		if (is_high())
  			rdat = (rdat >> 1) | 0x80;
  		else
  			rdat = rdat >> 1;
  
  		udelay(60);	/* at least 60 us */
  	}
  	/* copy the return value */
  	*data = rdat;
  }
  
  void board_get_enetaddr(uchar *enetaddr)
  {
  	unsigned char sn[6], err = NO_ERROR;
  
  	init_gpio();
  
  	read_2501_memory(sn, &err);
  
  	if (err == NO_ERROR) {
  		sprintf((char *)enetaddr, "%02x:%02x:%02x:%02x:%02x:%02x",
  				sn[0], sn[1], sn[2], sn[3], sn[4], sn[5]);
  		printf("MAC address: %s
  ", enetaddr);
  		setenv("ethaddr", (char *)enetaddr);
  	} else {
  		sprintf((char *)enetaddr, "00:01:02:03:04:05");
  		printf("Error reading MAC address.
  ");
  		printf("Setting default to %s
  ", enetaddr);
  		setenv("ethaddr", (char *)enetaddr);
  	}
  }