1/*
2 * linux/arch/sh/stboards/led.c
3 *
4 * Copyright (C) 2000 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 ST40STB1 HARP and compatible code.
10 */
11
12#include <linux/config.h>
13#include <asm/io.h>
14#include "harp.h"
15
16/* Harp: Flash LD10 (front pannel) connected to EPLD (IC8) */
17/* Overdrive: Flash LD1 (front panel) connected to EPLD (IC4) */
18/* Works for HARP and overdrive */
19static void mach_led(int position, int value)
20{
21	if (value) {
22		ctrl_outl(EPLD_LED_ON, EPLD_LED);
23	} else {
24		ctrl_outl(EPLD_LED_OFF, EPLD_LED);
25	}
26}
27
28#ifdef CONFIG_HEARTBEAT
29
30#include <linux/sched.h>
31
32/* acts like an actual heart beat -- ie thump-thump-pause... */
33void heartbeat_harp(void)
34{
35	static unsigned cnt = 0, period = 0, dist = 0;
36
37	if (cnt == 0 || cnt == dist)
38		mach_led( -1, 1);
39	else if (cnt == 7 || cnt == dist+7)
40		mach_led( -1, 0);
41
42	if (++cnt > period) {
43		cnt = 0;
44		/* The hyperbolic function below modifies the heartbeat period
45		 * length in dependency of the current (5min) load. It goes
46		 * through the points f(0)=126, f(1)=86, f(5)=51,
47		 * f(inf)->30. */
48		period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
49		dist = period / 4;
50	}
51}
52#endif
53