Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/sh64/kernel/led.c |
| 3 | * |
| 4 | * Copyright (C) 2002 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 | * Flash the LEDs |
| 10 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/stddef.h> |
| 12 | #include <linux/sched.h> |
| 13 | |
| 14 | void mach_led(int pos, int val); |
| 15 | |
| 16 | /* acts like an actual heart beat -- ie thump-thump-pause... */ |
| 17 | void heartbeat(void) |
| 18 | { |
| 19 | static unsigned int cnt = 0, period = 0, dist = 0; |
| 20 | |
| 21 | if (cnt == 0 || cnt == dist) { |
| 22 | mach_led(-1, 1); |
| 23 | } else if (cnt == 7 || cnt == dist + 7) { |
| 24 | mach_led(-1, 0); |
| 25 | } |
| 26 | |
| 27 | if (++cnt > period) { |
| 28 | cnt = 0; |
| 29 | |
| 30 | /* |
| 31 | * The hyperbolic function below modifies the heartbeat period |
| 32 | * length in dependency of the current (5min) load. It goes |
| 33 | * through the points f(0)=126, f(1)=86, f(5)=51, f(inf)->30. |
| 34 | */ |
| 35 | period = ((672 << FSHIFT) / (5 * avenrun[0] + |
| 36 | (7 << FSHIFT))) + 30; |
| 37 | dist = period / 4; |
| 38 | } |
| 39 | } |
| 40 | |