Attempting to consolidate the ARM LED code, this removes the
custom RealView LED trigger code to turn LEDs on and off in
response to CPU activity and replace it with a standard trigger.
(bryan.wu@xxxxxxxxxxxxx:
It moves arch/arm/kernel/leds.c syscore stubs into this trigger.
It also provides ledtrig_cpu trigger event stub in <linux/leds.h>.
Although it was inspired by ARM work, it can be used in other arch.)
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Bryan Wu <bryan.wu@xxxxxxxxxxxxx>
Reviewed-by: Jamie Iles <jamie@xxxxxxxxxxxxx>
Tested-by: Jochen Friedrich <jochen@xxxxxxxx>
---
drivers/leds/Kconfig | 10 +++
drivers/leds/Makefile | 1 +
drivers/leds/ledtrig-cpu.c | 138 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/leds.h | 23 +++++++
4 files changed, 172 insertions(+), 0 deletions(-)
create mode 100644 drivers/leds/ledtrig-cpu.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index ff4b8cf..cf02fb8 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -448,6 +448,16 @@ config LEDS_TRIGGER_BACKLIGHT
If unsure, say N.
+config LEDS_TRIGGER_CPU
+ tristate "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
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 890481c..0a3d5ad 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -55,4 +55,5 @@ 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
diff --git a/drivers/leds/ledtrig-cpu.c b/drivers/leds/ledtrig-cpu.c
new file mode 100644
index 0000000..d48c4b5
--- /dev/null
+++ b/drivers/leds/ledtrig-cpu.c
@@ -0,0 +1,138 @@
+/*
+ * 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 binded with any LEDs as other triggers does, either in 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@xxxxxxxxxx>
+ * Copyright 2011 - 2012 Bryan Wu <bryan.wu@xxxxxxxxxxxxx>
+ *
+ * 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"
+
+#define MAX_NAME_LEN 8
+
+static DEFINE_PER_CPU(struct led_trigger *, cpu_trig);
+static DEFINE_PER_CPU(char [MAX_NAME_LEN], 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)
+{
+ int cpuid = smp_processor_id();
+ struct led_trigger *trig;
+ char *name = __get_cpu_var(trig_name);
+
+ snprintf(name, MAX_NAME_LEN, "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)
+{
+ 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, MAX_NAME_LEN);
+}
+
+static int __init ledtrig_cpu_init(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ ledtrig_cpu_register();
+
+ register_syscore_ops(&ledtrig_cpu_syscore_ops);
+
+ return 0;
+}
+module_init(ledtrig_cpu_init);
+
+static void __exit ledtrig_cpu_exit(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ ledtrig_cpu_unregister();
+
+ unregister_syscore_ops(&ledtrig_cpu_syscore_ops);
+}
+module_exit(ledtrig_cpu_exit);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@xxxxxxxxxx>");
+MODULE_AUTHOR("Bryan Wu <bryan.wu@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("CPU LED trigger");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 5884def..1215b94 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -210,4 +210,27 @@ struct gpio_led_platform_data {
struct platform_device *gpio_led_register_device(
int id, const struct gpio_led_platform_data *pdata);
+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 */
+};
+#if defined(CONFIG_LEDS_TRIGGER_CPU) || defined(CONFIG_LEDS_TRIGGER_CPU_MODULE)
+/**
+ * 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.
+ */
+extern void ledtrig_cpu(enum cpu_led_event evt);
+#else
+static inline void ledtrig_cpu(enum cpu_led_event evt)
+{
+ return;
+}
+#endif
+
#endif /* __LINUX_LEDS_H_INCLUDED */
--
1.7.9.1
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