acrn-kernel/arch/sh64/kernel/led.c

42 lines
955 B
C

/*
* arch/sh64/kernel/led.c
*
* Copyright (C) 2002 Stuart Menefy <stuart.menefy@st.com>
*
* May be copied or modified under the terms of the GNU General Public
* License. See linux/COPYING for more information.
*
* Flash the LEDs
*/
#include <linux/config.h>
#include <linux/stddef.h>
#include <linux/sched.h>
void mach_led(int pos, int val);
/* acts like an actual heart beat -- ie thump-thump-pause... */
void heartbeat(void)
{
static unsigned int cnt = 0, period = 0, dist = 0;
if (cnt == 0 || cnt == dist) {
mach_led(-1, 1);
} else if (cnt == 7 || cnt == dist + 7) {
mach_led(-1, 0);
}
if (++cnt > period) {
cnt = 0;
/*
* The hyperbolic function below modifies the heartbeat period
* length in dependency of the current (5min) load. It goes
* through the points f(0)=126, f(1)=86, f(5)=51, f(inf)->30.
*/
period = ((672 << FSHIFT) / (5 * avenrun[0] +
(7 << FSHIFT))) + 30;
dist = period / 4;
}
}