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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/leds/trigger/ledtrig-cpu.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/leds/trigger/ledtrig-cpu.c')
-rw-r--r--kernel/drivers/leds/trigger/ledtrig-cpu.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/kernel/drivers/leds/trigger/ledtrig-cpu.c b/kernel/drivers/leds/trigger/ledtrig-cpu.c
new file mode 100644
index 000000000..aec0f02b6
--- /dev/null
+++ b/kernel/drivers/leds/trigger/ledtrig-cpu.c
@@ -0,0 +1,166 @@
+/*
+ * ledtrig-cpu.c - LED trigger based on CPU activity
+ *
+ * This LED trigger will be registered for each possible CPU and named as
+ * cpu0, cpu1, cpu2, cpu3, etc.
+ *
+ * It can be bound to any LED just like other triggers using either a
+ * board file or via sysfs interface.
+ *
+ * An API named ledtrig_cpu is exported for any user, who want to add CPU
+ * activity indication in their code
+ *
+ * Copyright 2011 Linus Walleij <linus.walleij@linaro.org>
+ * Copyright 2011 - 2012 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 <linux/rwsem.h>
+#include <linux/cpu.h>
+#include "../leds.h"
+
+#define MAX_NAME_LEN 8
+
+struct led_trigger_cpu {
+ char name[MAX_NAME_LEN];
+ struct led_trigger *_trig;
+};
+
+static DEFINE_PER_CPU(struct led_trigger_cpu, cpu_trig);
+
+/**
+ * ledtrig_cpu - emit a CPU event as a trigger
+ * @evt: CPU event to be emitted
+ *
+ * Emit a CPU event on a CPU core, which will trigger a
+ * binded LED to turn on or turn off.
+ */
+void ledtrig_cpu(enum cpu_led_event ledevt)
+{
+ struct led_trigger_cpu *trig = this_cpu_ptr(&cpu_trig);
+
+ /* 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->_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->_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 int ledtrig_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_STARTING:
+ ledtrig_cpu(CPU_LED_START);
+ break;
+ case CPU_DYING:
+ ledtrig_cpu(CPU_LED_STOP);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+
+static struct notifier_block ledtrig_cpu_nb = {
+ .notifier_call = ledtrig_cpu_notify,
+};
+
+static int __init ledtrig_cpu_init(void)
+{
+ int cpu;
+
+ /* Supports up to 9999 cpu cores */
+ BUILD_BUG_ON(CONFIG_NR_CPUS > 9999);
+
+ /*
+ * Registering CPU led trigger for each CPU core here
+ * ignores CPU hotplug, but after this CPU hotplug works
+ * fine with this trigger.
+ */
+ for_each_possible_cpu(cpu) {
+ struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu);
+
+ snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu);
+
+ led_trigger_register_simple(trig->name, &trig->_trig);
+ }
+
+ register_syscore_ops(&ledtrig_cpu_syscore_ops);
+ register_cpu_notifier(&ledtrig_cpu_nb);
+
+ pr_info("ledtrig-cpu: registered to indicate activity on CPUs\n");
+
+ return 0;
+}
+module_init(ledtrig_cpu_init);
+
+static void __exit ledtrig_cpu_exit(void)
+{
+ int cpu;
+
+ unregister_cpu_notifier(&ledtrig_cpu_nb);
+
+ for_each_possible_cpu(cpu) {
+ struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu);
+
+ led_trigger_unregister_simple(trig->_trig);
+ trig->_trig = NULL;
+ memset(trig->name, 0, MAX_NAME_LEN);
+ }
+
+ 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");