mini/seeprom.c

/*
	mini - a Free Software replacement for the Nintendo/BroadOn IOS.

	SEEPROM support

Copyright (C) 2008, 2009 	Sven Peter <svenpeter@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, version 2.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/
#include "types.h"
#include "utils.h"
#include "hollywood.h"
#include "start.h"
#include "gpio.h"

#define eeprom_delay() udelay(5)

void send_bits(int b, int bits)
{
	while(bits--)
	{
		if(b & (1 << bits))
			set32(HW_GPIO1OUT, GP_EEP_MOSI);
		else
			clear32(HW_GPIO1OUT, GP_EEP_MOSI);
		eeprom_delay();
		set32(HW_GPIO1OUT, GP_EEP_CLK);
		eeprom_delay();
		clear32(HW_GPIO1OUT, GP_EEP_CLK);
		eeprom_delay();
	}
}

int recv_bits(int bits)
{
	int res = 0;
	while(bits--)
	{
		res <<= 1;
		set32(HW_GPIO1OUT, GP_EEP_CLK);
		eeprom_delay();
		clear32(HW_GPIO1OUT, GP_EEP_CLK);
		eeprom_delay();
		res |= !!(read32(HW_GPIO1IN) & GP_EEP_MISO);
	}
	return res;
}

int seeprom_read(void *dst, int offset, int size)
{
	int i;
	u16 *ptr = (u16 *)dst;
	u16 recv;

	if(size & 1)
		return -1;

	clear32(HW_GPIO1OUT, GP_EEP_CLK);
	clear32(HW_GPIO1OUT, GP_EEP_CS);
	eeprom_delay();

	for(i = 0; i < size; ++i)
	{
		set32(HW_GPIO1OUT, GP_EEP_CS);
		send_bits((0x600 | (offset + i)), 11);
		recv = recv_bits(16);
		*ptr++ = recv;
		clear32(HW_GPIO1OUT, GP_EEP_CS);
		eeprom_delay();
	}

	return size;
}