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/arch/sh/boards/overdrive/led.c

https://bitbucket.org/evzijst/gittest
C | 59 lines | 34 code | 10 blank | 15 comment | 12 complexity | e02db002f340da103273557650d57471 MD5 | raw file
 1/*
 2 * linux/arch/sh/overdrive/led.c
 3 *
 4 * Copyright (C) 1999 Stuart Menefy <stuart.menefy@st.com>
 5 *
 6 * May be copied or modified under the terms of the GNU General Public
 7 * License.  See linux/COPYING for more information.
 8 *
 9 * This file contains an Overdrive specific LED feature.
10 */
11
12#include <linux/config.h>
13#include <asm/system.h>
14#include <asm/io.h>
15#include <asm/overdrive/overdrive.h>
16
17static void mach_led(int position, int value)
18{
19	unsigned long flags;
20	unsigned long reg;
21
22	local_irq_save(flags);
23	
24	reg = readl(OVERDRIVE_CTRL);
25	if (value) {
26		reg |= (1<<3);
27	} else {
28		reg &= ~(1<<3);
29	}
30	writel(reg, OVERDRIVE_CTRL);
31
32	local_irq_restore(flags);
33}
34
35#ifdef CONFIG_HEARTBEAT
36
37#include <linux/sched.h>
38
39/* acts like an actual heart beat -- ie thump-thump-pause... */
40void heartbeat_od(void)
41{
42	static unsigned cnt = 0, period = 0, dist = 0;
43
44	if (cnt == 0 || cnt == dist)
45		mach_led( -1, 1);
46	else if (cnt == 7 || cnt == dist+7)
47		mach_led( -1, 0);
48
49	if (++cnt > period) {
50		cnt = 0;
51		/* The hyperbolic function below modifies the heartbeat period
52		 * length in dependency of the current (5min) load. It goes
53		 * through the points f(0)=126, f(1)=86, f(5)=51,
54		 * f(inf)->30. */
55		period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
56		dist = period / 4;
57	}
58}
59#endif /* CONFIG_HEARTBEAT */