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authorKim, Milo <Milo.Kim@ti.com>2013-02-20 00:36:01 -0800
committerBryan Wu <cooloney@gmail.com>2013-04-01 11:04:48 -0700
commitf07fb52107c881f35eaff09fe990a4dfd0f7e62a (patch)
treeb4b338f39799781648b5c6e0782c9ad746733bca /drivers/leds/trigger/ledtrig-cpu.c
parentff45262a85dbf1bc74463c5dcea1d71a406d4d8e (diff)
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leds: move LED trigger drivers into new subdirectory
For better driver management, new subdirectory, 'trigger' is created. All LED trigger drivers are moved into this directory. Internal header, 'leds.h' is included in each LED trigger drivers. Fix the location of header file, "leds.h" -> "../leds.h" in driver files. One exception is here, 'ledtrig-timer.c'. There is no need to include 'leds.h'. so '#include "leds.h"' line was removed. Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
Diffstat (limited to 'drivers/leds/trigger/ledtrig-cpu.c')
-rw-r--r--drivers/leds/trigger/ledtrig-cpu.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/leds/trigger/ledtrig-cpu.c b/drivers/leds/trigger/ledtrig-cpu.c
new file mode 100644
index 000000000000..118335eccc56
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-cpu.c
@@ -0,0 +1,142 @@
+/*
+ * 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 "../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 = &__get_cpu_var(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 __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);
+
+ 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;
+
+ 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");