Merge remote-tracking branch 'leds/for-mm'
[linux-2.6/next.git] / arch / arm / plat-versatile / sched-clock.c
blob3d6a4c292cab904badbf06be1075c2d709ce1413
1 /*
2 * linux/arch/arm/plat-versatile/sched-clock.c
4 * Copyright (C) 1999 - 2003 ARM Limited
5 * Copyright (C) 2000 Deep Blue Solutions Ltd
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include <linux/io.h>
22 #include <linux/sched.h>
24 #include <asm/sched_clock.h>
25 #include <plat/sched_clock.h>
27 static DEFINE_CLOCK_DATA(cd);
28 static void __iomem *ctr;
31 * Constants generated by clocks_calc_mult_shift(m, s, 24MHz, NSEC_PER_SEC, 60).
32 * This gives a resolution of about 41ns and a wrap period of about 178s.
34 #define SC_MULT 2796202667u
35 #define SC_SHIFT 26
37 unsigned long long notrace sched_clock(void)
39 if (ctr) {
40 u32 cyc = readl(ctr);
41 return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0,
42 SC_MULT, SC_SHIFT);
43 } else
44 return 0;
47 static void notrace versatile_update_sched_clock(void)
49 u32 cyc = readl(ctr);
50 update_sched_clock(&cd, cyc, (u32)~0);
53 void __init versatile_sched_clock_init(void __iomem *reg, unsigned long rate)
55 ctr = reg;
56 init_fixed_sched_clock(&cd, versatile_update_sched_clock,
57 32, rate, SC_MULT, SC_SHIFT);