Messages in this thread Patch in this message | | | From | Bryan Wu <> | Subject | [PATCH 3/3] led-triggers: create a trigger for CPU activity | Date | Thu, 8 Mar 2012 17:11:03 +0800 |
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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@canonical.com: 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@rpsys.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com> Tested-by: Jochen Friedrich <jochen@scram.de> --- drivers/leds/Kconfig | 10 ++++ drivers/leds/Makefile | 1 + drivers/leds/ledtrig-cpu.c | 119 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/leds.h | 15 ++++++ 4 files changed, 145 insertions(+), 0 deletions(-) create mode 100644 drivers/leds/ledtrig-cpu.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 3f17f0d..f7f4761 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -457,6 +457,16 @@ 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 1fc6875..6629916 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -56,4 +56,5 @@ 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..49f7879 --- /dev/null +++ b/drivers/leds/ledtrig-cpu.c @@ -0,0 +1,119 @@ +/* + * 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"); diff --git a/include/linux/leds.h b/include/linux/leds.h index 5884def..2afecb7 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -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); +#if defined(CONFIG_LEDS_TRIGGER_CPU) || defined(CONFIG_LEDS_TRIGGER_CPU_MODULE) +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 */ -- 1.7.9
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