6ab2417b2420de078be8d53f59f5f68376434b02
[openocd.git] / contrib / loaders / flash / at91sam7x / dcc.c
1 /***************************************************************************
2 * Copyright (C) 2007 by Pavel Chromy *
3 * chromy@asix.cz *
4 * *
5 * This program is free software; you can redistribute it and/or modify *
6 * it under the terms of the GNU General Public License as published by *
7 * the Free Software Foundation; either version 2 of the License, or *
8 * (at your option) any later version. *
9 * *
10 * This program is distributed in the hope that it will be useful, *
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13 * GNU General Public License for more details. *
14 * *
15 * You should have received a copy of the GNU General Public License *
16 * along with this program; if not, write to the *
17 * Free Software Foundation, Inc., *
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
19 ***************************************************************************/
20 #include "dcc.h"
21
22
23 /* debug channel read (debugger->MCU) */
24 uint32 dcc_rd(void)
25 {
26 volatile uint32 dcc_reg;
27
28 do {
29 asm volatile ("mrc p14, 0, %0, C0, C0" : "=r" (dcc_reg) :);
30 } while ((dcc_reg&1) == 0);
31
32 asm volatile ("mrc p14, 0, %0, C1, C0" : "=r" (dcc_reg) :);
33 return dcc_reg;
34 }
35
36
37 /* debug channel write (MCU->debugger) */
38 int dcc_wr(uint32 data)
39 {
40 volatile uint32 dcc_reg;
41
42 do {
43 asm volatile ("mrc p14, 0, %0, C0, C0" : "=r" (dcc_reg) :);
44 /* operation controled by master, cancel operation
45 upon reception of data for immediate response */
46 if (dcc_reg&1) return -1;
47 } while (dcc_reg&2);
48
49 asm volatile ("mcr p14, 0, %0, C1, C0" : : "r" (data));
50 return 0;
51 }