1 /*
2 * Cobalt time initialization.
3 *
4 * Copyright (C) 2007 Yoichi Yuasa <yuasa@linux-mips.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20 #include <linux/i8253.h>
21 #include <linux/init.h>
22
23 #include <asm/gt64120.h>
24 #include <asm/time.h>
25
26 #define GT641XX_BASE_CLOCK 50000000 /* 50MHz */
27
plat_time_init(void)28 void __init plat_time_init(void)
29 {
30 u32 start, end;
31 int i = HZ / 10;
32
33 setup_pit_timer();
34
35 gt641xx_set_base_clock(GT641XX_BASE_CLOCK);
36
37 /*
38 * MIPS counter frequency is measured during a 100msec interval
39 * using GT64111 timer0.
40 */
41 while (!gt641xx_timer0_state())
42 ;
43
44 start = read_c0_count();
45
46 while (i--)
47 while (!gt641xx_timer0_state())
48 ;
49
50 end = read_c0_count();
51
52 mips_hpt_frequency = (end - start) * 10;
53 printk(KERN_INFO "MIPS counter frequency %dHz\n", mips_hpt_frequency);
54 }
55