@@ -430,6 +430,16 @@ config LEDS_TRIGGER_BACKLIGHT
If unsure, say N.
+config LEDS_TRIGGER_CPU
+ bool "LED CPU Trigger"
+ depends on LEDS_TRIGGERS
+ help
+ This allows LEDs to be controlled by active CPUs. This shows
+ the active CPUs across an array of LEDs so you can see what
+ CPUs are active on the system at any given moment.
+
+ If unsure, say N.
+
config LEDS_TRIGGER_GPIO
tristate "LED GPIO Trigger"
depends on LEDS_TRIGGERS
@@ -53,4 +53,5 @@ obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK) += ledtrig-ide-disk.o
obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT) += ledtrig-heartbeat.o
obj-$(CONFIG_LEDS_TRIGGER_BACKLIGHT) += ledtrig-backlight.o
obj-$(CONFIG_LEDS_TRIGGER_GPIO) += ledtrig-gpio.o
+obj-$(CONFIG_LEDS_TRIGGER_CPU) += ledtrig-cpu.o
obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON) += ledtrig-default-on.o
new file mode 100644
@@ -0,0 +1,120 @@
+/*
+ * ledtrig-cpu.c - LED trigger based on CPU activity
+ *
+ * Copyright 2011 Linus Walleij <linus.walleij@linaro.org>
+ * Copyright 2011 Bryan Wu <bryan.wu@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/percpu.h>
+#include <linux/syscore_ops.h>
+#include "leds.h"
+
+static DEFINE_PER_CPU(struct led_trigger *, cpu_trig);
+static DEFINE_PER_CPU(char [8], trig_name);
+
+void ledtrig_cpu(enum cpu_led_event ledevt)
+{
+ struct led_trigger *trig = __get_cpu_var(cpu_trig);
+
+ if (!trig)
+ return;
+
+ /* Locate the correct CPU LED */
+
+ switch (ledevt) {
+ case CPU_LED_IDLE_END:
+ case CPU_LED_START:
+ /* Will turn the LED on, max brightness */
+ led_trigger_event(trig, LED_FULL);
+ break;
+
+ case CPU_LED_IDLE_START:
+ case CPU_LED_STOP:
+ case CPU_LED_HALTED:
+ /* Will turn the LED off */
+ led_trigger_event(trig, LED_OFF);
+ break;
+
+ default:
+ /* Will leave the LED as it is */
+ break;
+ }
+}
+EXPORT_SYMBOL(ledtrig_cpu);
+
+static int ledtrig_cpu_syscore_suspend(void)
+{
+ ledtrig_cpu(CPU_LED_STOP);
+ return 0;
+}
+
+static void ledtrig_cpu_syscore_resume(void)
+{
+ ledtrig_cpu(CPU_LED_START);
+}
+
+static void ledtrig_cpu_syscore_shutdown(void)
+{
+ ledtrig_cpu(CPU_LED_HALTED);
+}
+
+static struct syscore_ops ledtrig_cpu_syscore_ops = {
+ .shutdown = ledtrig_cpu_syscore_shutdown,
+ .suspend = ledtrig_cpu_syscore_suspend,
+ .resume = ledtrig_cpu_syscore_resume,
+};
+
+static void __init ledtrig_cpu_register(void *info)
+{
+ int cpuid = smp_processor_id();
+ struct led_trigger *trig;
+ char *name = __get_cpu_var(trig_name);
+
+ snprintf(name, 8, "cpu%d", cpuid);
+ led_trigger_register_simple(name, &trig);
+
+ pr_info("LED trigger %s indicate activity on CPU %d\n",
+ trig->name, cpuid);
+
+ __get_cpu_var(cpu_trig) = trig;
+}
+
+static void __exit ledtrig_cpu_unregister(void *info)
+{
+ struct led_trigger *trig = __get_cpu_var(cpu_trig);
+ char *name = __get_cpu_var(trig_name);
+
+ led_trigger_unregister_simple(trig);
+ __get_cpu_var(cpu_trig) = NULL;
+ memset(name, 0, 8);
+}
+
+static int __init ledtrig_cpu_init(void)
+{
+ on_each_cpu(ledtrig_cpu_register, NULL, 1);
+ register_syscore_ops(&ledtrig_cpu_syscore_ops);
+
+ return 0;
+}
+module_init(ledtrig_cpu_init);
+
+static void __exit ledtrig_cpu_exit(void)
+{
+ on_each_cpu(ledtrig_cpu_unregister, NULL, 1);
+ unregister_syscore_ops(&ledtrig_cpu_syscore_ops);
+}
+module_exit(ledtrig_cpu_exit);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
+MODULE_AUTHOR("Bryan Wu <bryan.wu@canonical.com>");
+MODULE_DESCRIPTION("CPU LED trigger");
+MODULE_LICENSE("GPL");
@@ -210,4 +210,19 @@ struct gpio_led_platform_data {
struct platform_device *gpio_led_register_device(
int id, const struct gpio_led_platform_data *pdata);
+#ifdef CONFIG_LEDS_TRIGGER_CPU
+enum cpu_led_event {
+ CPU_LED_IDLE_START, /* CPU enters idle */
+ CPU_LED_IDLE_END, /* CPU idle ends */
+ CPU_LED_START, /* Machine starts, especially resume */
+ CPU_LED_STOP, /* Machine stops, especially suspend */
+ CPU_LED_HALTED, /* Machine shutdown */
+};
+
+/* Use this routine to handle LEDs */
+extern void ledtrig_cpu(enum cpu_led_event evt);
+#else
+#define ledtrig_cpu(evt) do {} while (0)
+#endif
+
#endif /* __LINUX_LEDS_H_INCLUDED */