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/* Copyright (C) 2013 by John Cronin <jncronin@tysos.org>
*
* 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 <stdint.h>
#include "mbox.h"
#include "mmio.h"
#define MBOX_FULL 0x80000000
#define MBOX_EMPTY 0x40000000
static uint32_t mbox_base = MBOX_BASE;
void mbox_set_base(uint32_t base)
{
mbox_base = base;
}
uint32_t mbox_read(uint8_t channel)
{
while(1)
{
while(mmio_read(mbox_base + MBOX_STATUS) & MBOX_EMPTY);
uint32_t data = mmio_read(mbox_base + MBOX_READ);
uint8_t read_channel = (uint8_t)(data & 0xf);
if(read_channel == channel)
return (data & 0xfffffff0);
}
}
void mbox_write(uint8_t channel, uint32_t data)
{
while(mmio_read(mbox_base + MBOX_STATUS) & MBOX_FULL);
mmio_write(mbox_base + MBOX_WRITE, (data & 0xfffffff0) | (uint32_t)(channel & 0xf));
}