tinyriscv-openocd/contrib/loaders/flash/at91sam7x/dcc.c

50 lines
1.9 KiB
C

/***************************************************************************
* Copyright (C) 2007 by Pavel Chromy *
* chromy@asix.cz *
* *
* 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, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
#include "dcc.h"
/* debug channel read (debugger->MCU) */
uint32 dcc_rd(void)
{
volatile uint32 dcc_reg;
do {
asm volatile ("mrc p14, 0, %0, C0, C0" : "=r" (dcc_reg) :);
} while ((dcc_reg&1) == 0);
asm volatile ("mrc p14, 0, %0, C1, C0" : "=r" (dcc_reg) :);
return dcc_reg;
}
/* debug channel write (MCU->debugger) */
int dcc_wr(uint32 data)
{
volatile uint32 dcc_reg;
do {
asm volatile ("mrc p14, 0, %0, C0, C0" : "=r" (dcc_reg) :);
/* operation controled by master, cancel operation
upon reception of data for immediate response */
if (dcc_reg&1) return -1;
} while (dcc_reg&2);
asm volatile ("mcr p14, 0, %0, C1, C0" : : "r" (data));
return 0;
}