Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758038Ab2EAPCV (ORCPT ); Tue, 1 May 2012 11:02:21 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:46175 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757918Ab2EAPCR (ORCPT ); Tue, 1 May 2012 11:02:17 -0400 From: Bryan Wu To: linux@arm.linux.org.uk, rpurdie@rpsys.net, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linus.walleij@linaro.org, akpm@linux-foundation.org, arnd.bergmann@linaro.org, nicolas.pitre@linaro.org, tim.gardner@canonical.com Subject: [PATCH 02/19] led-triggers: create a trigger for CPU activity Date: Tue, 1 May 2012 23:01:29 +0800 Message-Id: <1335884506-15370-3-git-send-email-bryan.wu@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1335884506-15370-1-git-send-email-bryan.wu@canonical.com> References: <1335884506-15370-1-git-send-email-bryan.wu@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7287 Lines: 255 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 introduces several syscore stubs into this trigger. It also provides ledtrig_cpu trigger event stub in . Although it was inspired by ARM work, it can be used in other arch.) Cc: Richard Purdie Signed-off-by: Linus Walleij Signed-off-by: Bryan Wu Reviewed-by: Jamie Iles Tested-by: Jochen Friedrich --- drivers/leds/Kconfig | 10 +++ drivers/leds/Makefile | 1 + drivers/leds/ledtrig-cpu.c | 163 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/leds.h | 16 +++++ 4 files changed, 190 insertions(+) create mode 100644 drivers/leds/ledtrig-cpu.c diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 5f12659..dbf8a4c 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -465,6 +465,16 @@ 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 which + 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 9475bbb..ea1efb2 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..b312056 --- /dev/null +++ b/drivers/leds/ledtrig-cpu.c @@ -0,0 +1,163 @@ +/* + * 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 + * Copyright 2011 - 2012 Bryan Wu + * + * 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 +#include +#include +#include +#include +#include +#include +#include "leds.h" + +#define MAX_NAME_LEN 8 + +struct led_trigger_cpu { + char name[MAX_NAME_LEN]; + struct led_trigger *_trig; + struct mutex lock; + int lock_is_inited; +}; + +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); + + /* mutex lock should be initialized before calling mutex_call() */ + if (!trig->lock_is_inited) + return; + + mutex_lock(&trig->lock); + + /* 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; + } + + mutex_unlock(&trig->lock); +} +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); + + mutex_init(&trig->lock); + + snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu); + + mutex_lock(&trig->lock); + led_trigger_register_simple(trig->name, &trig->_trig); + trig->lock_is_inited = 1; + mutex_unlock(&trig->lock); + } + + 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); + + mutex_lock(&trig->lock); + + led_trigger_unregister_simple(trig->_trig); + trig->_trig = NULL; + memset(trig->name, 0, MAX_NAME_LEN); + trig->lock_is_inited = 0; + + mutex_unlock(&trig->lock); + mutex_destroy(&trig->lock); + } + + unregister_syscore_ops(&ledtrig_cpu_syscore_ops); +} +module_exit(ledtrig_cpu_exit); + +MODULE_AUTHOR("Linus Walleij "); +MODULE_AUTHOR("Bryan Wu "); +MODULE_DESCRIPTION("CPU LED trigger"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/leds.h b/include/linux/leds.h index 39eee41..aaf88b0 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -212,4 +212,20 @@ 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) +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 */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/