| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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 | |
| 17 | static 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... */ |
| 40 | void 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 */ |