Files
osc2025/lib/mbox.c
2025-04-08 06:59:49 +08:00

126 lines
3.4 KiB
C

/*
* Copyright (C) 2018 bzt (bztsrc@github)
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
*/
#include <gpio.h>
#include <mbox.h>
/* mailbox message buffer */
volatile unsigned int __attribute__((aligned(16))) mbox[36];
#define VIDEOCORE_MBOX (MMIO_BASE+0x0000B880)
#define MBOX_READ ((volatile unsigned int*)(VIDEOCORE_MBOX+0x0))
#define MBOX_POLL ((volatile unsigned int*)(VIDEOCORE_MBOX+0x10))
#define MBOX_SENDER ((volatile unsigned int*)(VIDEOCORE_MBOX+0x14))
#define MBOX_STATUS ((volatile unsigned int*)(VIDEOCORE_MBOX+0x18))
#define MBOX_CONFIG ((volatile unsigned int*)(VIDEOCORE_MBOX+0x1C))
#define MBOX_WRITE ((volatile unsigned int*)(VIDEOCORE_MBOX+0x20))
#define MBOX_RESPONSE 0x80000000
#define MBOX_FULL 0x80000000
#define MBOX_EMPTY 0x40000000
#define MAILBOX_BASE MMIO_BASE + 0xb880
#define REQUEST_SUCCEED 0x80000000
#define REQUEST_FAILED 0x80000001
#define TAG_MBOX_REQUEST 0x00000000
/**
* Make a mailbox call. Returns 0 on failure, non-zero on success
*/
int mbox_call(unsigned char ch)
{
unsigned int r = (((unsigned int)((unsigned long)&mbox)&~0xF) | (ch&0xF));
/* wait until we can write to the mailbox */
do{asm volatile("nop");}while(*MBOX_STATUS & MBOX_FULL);
/* write the address of our message to the mailbox with channel identifier */
*MBOX_WRITE = r;
/* now wait for the response */
while(1) {
/* is there a response? */
do{asm volatile("nop");}while(*MBOX_STATUS & MBOX_EMPTY);
/* is it a response to our message? */
if(r == *MBOX_READ)
/* is it a valid successful response? */
return mbox[1]==MBOX_RESPONSE;
}
return 0;
}
unsigned int get_board_revision(void)
{
mbox[0] = 36 * 4;
mbox[1] = MBOX_REQUEST;
// tags
mbox[2] = MBOX_TAG_BOARD_REVISION;
mbox[3] = 4;
mbox[4] = TAG_MBOX_REQUEST;
mbox[5] = 0; // value buffer
mbox[6] = MBOX_TAG_LAST;
mbox_call(MBOX_CH_PROP);
return mbox[5];
}
unsigned int get_memory_base_addr(void)
{
mbox[0] = 36 * 4;
mbox[1] = MBOX_REQUEST;
// tags
mbox[2] = MBOX_TAG_ARM_MEMORY;
mbox[3] = 8;
mbox[4] = 8;
mbox[5] = 0;
mbox[6] = 0;
mbox[7] = MBOX_TAG_LAST;
mbox_call(MBOX_CH_PROP);
return mbox[5];
}
unsigned int get_memory_size(void)
{
mbox[0] = 36 * 4;
mbox[1] = MBOX_REQUEST;
// tags
mbox[2] = MBOX_TAG_ARM_MEMORY;
mbox[3] = 8;
mbox[4] = 8;
mbox[5] = 0;
mbox[6] = 0;
mbox[7] = MBOX_TAG_LAST;
mbox_call(MBOX_CH_PROP);
return mbox[6];
}