50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
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/*
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* File : mbox.c
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* Copyright (c) 2006-2018, RT-Thread Development Team
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Change Logs:
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* Date Author Notes
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* 2019-08-29 zdzn first version
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*/
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/* mailbox message buffer */
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#include "mbox.h"
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#include "mmu.h"
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//volatile unsigned int __attribute__((aligned(16))) mbox[36];
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volatile unsigned int *mbox = (volatile unsigned int *) MBOX_ADDR;
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/**
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* Make a mailbox call. Returns 0 on failure, non-zero on success
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*/
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int mbox_call(unsigned char ch, int mmu_enable)
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{
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unsigned int r = (((MBOX_ADDR)&~0xF) | (ch&0xF));
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if(mmu_enable)
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r = BUS_ADDRESS(r);
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/* wait until we can write to the mailbox */
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do
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{
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asm volatile("nop");
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} while (*MBOX_STATUS & MBOX_FULL);
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/* write the address of our message to the mailbox with channel identifier */
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*MBOX_WRITE = r;
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/* now wait for the response */
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// rt_kprintf("mailbox request %x\n",r);
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while(1)
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{
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/* is there a response? */
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do
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{
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asm volatile("nop");
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} while (*MBOX_STATUS & MBOX_EMPTY);
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/* is it a response to our message? */
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if (r == *MBOX_READ){
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/* is it a valid successful response? */
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// rt_kprintf("mbox: %x, %x, %x, %x, %x, %x, %x, %x\n", mbox[0], mbox[1], mbox[2], mbox[3], mbox[4], mbox[5], mbox[6], mbox[7]);
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return mbox[1] == MBOX_RESPONSE;
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}
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}
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return 0;
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}
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