mailboxbomb/loader/usbgecko.c

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2015-09-03 05:13:18 +02:00
// Copyright 2008-2009 Segher Boessenkool <segher@kernel.crashing.org>
// This code is licensed to you under the terms of the GNU GPL, version 2;
// see file COPYING or http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
// Based on code:
// Copyright (c) 2008 - Nuke - <wiinuke@gmail.com>
#include "loader.h"
static void exi_write(u32 addr, u32 x)
{
write32(0x0d006800 + addr, x);
}
static u32 exi_read(u32 addr)
{
return read32(0x0d006800 + addr);
}
#define EXI_CH1_STATUS 0x14
#define EXI_CH1_CONTROL 0x20
#define EXI_CH1_DATA 0x24
static void usbgecko_deselect_device(void)
{
exi_write(EXI_CH1_STATUS, 0);
}
static void usbgecko_select_device(void)
{
// device 0, 16MHz
exi_write(EXI_CH1_STATUS, 0xc0);
}
static void usbgecko_wait_for_transfer_complete(void)
{
while (exi_read(EXI_CH1_CONTROL) & 1)
;
}
u8 usbgecko_flash_read8(u32 offset)
{
u8 x;
usbgecko_deselect_device();
usbgecko_select_device();
exi_write(EXI_CH1_DATA, 0xf0000000 | (offset << 9));
exi_write(EXI_CH1_CONTROL, 0x35); // 4 bytes immediate write
usbgecko_wait_for_transfer_complete();
usbgecko_select_device();
exi_write(EXI_CH1_CONTROL, 0x39); // 4 bytes immediate read/write
usbgecko_wait_for_transfer_complete();
x = exi_read(EXI_CH1_DATA) >> 23;
usbgecko_deselect_device();
return x;
}
u32 usbgecko_flash_read32(u32 offset)
{
u32 x, i;
x = 0;
for (i = 0; i < 4; i++)
x = (x << 8) | usbgecko_flash_read8(offset++);
return x;
}
static int usbgecko_console_enabled = 0;
static u32 usbgecko_command(u32 command)
{
u32 x;
usbgecko_select_device();
exi_write(EXI_CH1_DATA, command);
exi_write(EXI_CH1_CONTROL, 0x19); // 2 bytes immediate read/write
usbgecko_wait_for_transfer_complete();
x = exi_read(EXI_CH1_DATA);
usbgecko_deselect_device();
return x;
}
int usbgecko_checkgecko(void)
{
return usbgecko_command(0x90000000) == 0x04700000;
}
void usbgecko_console_putc(u8 c)
{
u32 x;
if (!usbgecko_console_enabled)
return;
if (c == '\n')
usbgecko_console_putc('\r');
x = usbgecko_command(0xb0000000 | (c << 20));
}
static void usbgecko_flush(void)
{
u32 x;
do {
x = usbgecko_command(0xa0000000);
} while (x & 0x08000000);
}
void usbgecko_init(void)
{
if (!usbgecko_checkgecko())
return;
usbgecko_console_enabled = 1;
usbgecko_flush();
}