70 lines
2.4 KiB
C
70 lines
2.4 KiB
C
|
/*
|
||
|
|
Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
|
||
|
|
|
||
|
|
This file is part of Aedrix.
|
||
|
|
|
||
|
|
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; either version 2 of the License, or
|
||
|
|
(at your option) any later version.
|
||
|
|
|
||
|
|
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.,
|
||
|
|
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <types.h>
|
||
|
|
|
||
|
|
/* Mailbox Memory-Mapped Registers */
|
||
|
|
#define VC_MMU_IO_OFFSET(addr) (addr - 0x7E000000 + 0x20000000)
|
||
|
|
|
||
|
|
#define MBOX0_READ VC_MMU_IO_OFFSET(0x7E00B880)
|
||
|
|
/* MBOX0_READ layout:
|
||
|
|
31-4 data The 28 bits of data sent to the CPU
|
||
|
|
3-0 channel The mailbox channel number from which the data originated */
|
||
|
|
#define MBOX0_PEEK VC_MMU_IO_OFFSET(0x7E00B890) //Read from the mailbox without removing data from it.
|
||
|
|
#define MBOX0_SENDER VC_MMU_IO_OFFSET(0x7E00B894) //Sender ID (bottom 2 bits only)
|
||
|
|
#define MBOX0_STATUS VC_MMU_IO_OFFSET(0x7E00B898)
|
||
|
|
/* MBOX0_STATUS layout:
|
||
|
|
31 full Set if the mailbox is full, and thus no more data can be written to it.
|
||
|
|
30 empty Set if the mailbox is empty, and thus no more data is available to be read from it.
|
||
|
|
29-0 unused? */
|
||
|
|
#define MBOX0_CONFIG VC_MMU_IO_OFFSET(0x7E00B89C)
|
||
|
|
#define MBOX0_WRITE VC_MMU_IO_OFFSET(0x7E00B8A0) //also MBOX1_READ?
|
||
|
|
/* MBOX0_WRITE layout:
|
||
|
|
31-4 data The 28 bits of data to be sent
|
||
|
|
3-0 channel The mailbox channel to send data to */
|
||
|
|
|
||
|
|
#define MBOX0_STATUS_FULL 0x80000000
|
||
|
|
#define MBOX0_STATUS_EMPTY 0x40000000
|
||
|
|
|
||
|
|
|
||
|
|
uint32 mailbox_read(uint32 channel) {
|
||
|
|
uint32 mbox_msg;
|
||
|
|
while (1) {
|
||
|
|
int i;
|
||
|
|
for (i = 0; *(volatile uint32 *)MBOX0_STATUS & MBOX0_STATUS_EMPTY; i++) {
|
||
|
|
if (i >= 1<<20)
|
||
|
|
return 0xFFFFFFFF;
|
||
|
|
}
|
||
|
|
|
||
|
|
mbox_msg = *(volatile uint32 *)MBOX0_READ;
|
||
|
|
if ((mbox_msg & 0xf) == channel)
|
||
|
|
return mbox_msg & ~0xf;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void mailbox_write(uint32 channel, uint32 data) {
|
||
|
|
channel &= 0xf;
|
||
|
|
data &= ~0xf;
|
||
|
|
|
||
|
|
while (*(volatile uint32 *)MBOX0_STATUS & MBOX0_STATUS_FULL);
|
||
|
|
|
||
|
|
*(volatile uint32 *)MBOX0_WRITE = channel | data;
|
||
|
|
}
|