1 /*
2 * linux/arch/arm/mach-clps711x/time.c
3 *
4 * Copyright (C) 2001 Deep Blue Solutions Ltd.
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 version 2 as
8 * published by the Free Software Foundation.
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 Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19 #include <linux/sched.h>
20 #include <linux/init.h>
21
22 #include <asm/hardware.h>
23 #include <asm/io.h>
24 #include <asm/hardware/clps7111.h>
25
26 extern unsigned long (*gettimeoffset)(void);
27
28 /*
29 * gettimeoffset() returns time since last timer tick, in usecs.
30 *
31 * 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy.
32 * 'tick' is usecs per jiffy.
33 */
clps711x_gettimeoffset(void)34 static unsigned long clps711x_gettimeoffset(void)
35 {
36 unsigned long hwticks;
37 hwticks = LATCH - (clps_readl(TC2D) & 0xffff); /* since last underflow */
38 return (hwticks * tick) / LATCH;
39 }
40
clps711x_setup_timer(void)41 void __init clps711x_setup_timer(void)
42 {
43 unsigned int syscon;
44
45 gettimeoffset = clps711x_gettimeoffset;
46
47 syscon = clps_readl(SYSCON1);
48 syscon |= SYSCON1_TC2S | SYSCON1_TC2M;
49 clps_writel(syscon, SYSCON1);
50
51 clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */
52
53 xtime.tv_sec = clps_readl(RTCDR);
54 }
55