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-rw-r--r--arch/sh/boards/overdrive/led.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/sh/boards/overdrive/led.c b/arch/sh/boards/overdrive/led.c
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+++ b/arch/sh/boards/overdrive/led.c
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+/*
+ * 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 */