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Diffstat (limited to 'arch/sh/boards/overdrive/led.c')
| -rw-r--r-- | arch/sh/boards/overdrive/led.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/sh/boards/overdrive/led.c b/arch/sh/boards/overdrive/led.c new file mode 100644 index 00000000000..734742e9227 --- /dev/null +++ b/arch/sh/boards/overdrive/led.c @@ -0,0 +1,59 @@ +/* + * linux/arch/sh/overdrive/led.c + * + * Copyright (C) 1999 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. + * + * This file contains an Overdrive specific LED feature. + */ + +#include <linux/config.h> +#include <asm/system.h> +#include <asm/io.h> +#include <asm/overdrive/overdrive.h> + +static void mach_led(int position, int value) +{ + unsigned long flags; + unsigned long reg; + + local_irq_save(flags); + + reg = readl(OVERDRIVE_CTRL); + if (value) { + reg |= (1<<3); + } else { + reg &= ~(1<<3); + } + writel(reg, OVERDRIVE_CTRL); + + local_irq_restore(flags); +} + +#ifdef CONFIG_HEARTBEAT + +#include <linux/sched.h> + +/* acts like an actual heart beat -- ie thump-thump-pause... */ +void heartbeat_od(void) +{ + static unsigned 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; + } +} +#endif /* CONFIG_HEARTBEAT */ |