1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Cobalt time initialization.
4 *
5 * Copyright (C) 2007 Yoichi Yuasa <yuasa@linux-mips.org>
6 */
7 #include <linux/i8253.h>
8 #include <linux/init.h>
9
10 #include <asm/gt64120.h>
11 #include <asm/time.h>
12
13 #define GT641XX_BASE_CLOCK 50000000 /* 50MHz */
14
15 void __init plat_time_init(void)
16 {
17 u32 start, end;
18 int i = HZ / 10;
19
20 setup_pit_timer();
21
22 gt641xx_set_base_clock(GT641XX_BASE_CLOCK);
23
24 /*
25 * MIPS counter frequency is measured during a 100msec interval
26 * using GT64111 timer0.
27 */
28 while (!gt641xx_timer0_state())
29 ;
30
31 start = read_c0_count();
32
33 while (i--)
34 while (!gt641xx_timer0_state())
35 ;
36
37 end = read_c0_count();
38
39 mips_hpt_frequency = (end - start) * 10;
40 printk(KERN_INFO "MIPS counter frequency %dHz\n", mips_hpt_frequency);
41 }
42
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