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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-02 03:46:13 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-02 03:46:13 +0200 |
commit | 8f446a7a069e0af0639385f67c78ee2279bca04c (patch) | |
tree | 580cf495616b36ca0af0826afa87c430cdc1e7cb /drivers/leds/ledtrig-cpu.c | |
parent | Merge tag 'soc2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc (diff) | |
parent | Merge branch 'samsung/pinctrl' into next/drivers (diff) | |
download | linux-8f446a7a069e0af0639385f67c78ee2279bca04c.tar.xz linux-8f446a7a069e0af0639385f67c78ee2279bca04c.zip |
Merge tag 'drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM soc driver specific changes from Olof Johansson:
- A long-coming conversion of various platforms to a common LED
infrastructure
- AT91 is moved over to use the newer MCI driver for MMC
- Pincontrol conversions for samsung platforms
- DT bindings for gscaler on samsung
- i2c driver fixes for tegra, acked by i2c maintainer
Fix up conflicts as per Olof.
* tag 'drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (48 commits)
drivers: bus: omap_l3: use resources instead of hardcoded irqs
pinctrl: exynos: Fix wakeup IRQ domain registration check
pinctrl: samsung: Uninline samsung_pinctrl_get_soc_data
pinctrl: exynos: Correct the detection of wakeup-eint node
pinctrl: exynos: Mark exynos_irq_demux_eint as inline
pinctrl: exynos: Handle only unmasked wakeup interrupts
pinctrl: exynos: Fix typos in gpio/wkup _irq_mask
pinctrl: exynos: Set pin function to EINT in irq_set_type of GPIO EINTa
drivers: bus: Move the OMAP interconnect driver to drivers/bus/
i2c: tegra: dynamically control fast clk
i2c: tegra: I2_M_NOSTART functionality not supported in Tegra20
ARM: tegra: clock: remove unused clock entry for i2c
ARM: tegra: clock: add connection name in i2c clock entry
i2c: tegra: pass proper name for getting clock
ARM: tegra: clock: add i2c fast clock entry in clock table
ARM: EXYNOS: Adds G-Scaler device from Device Tree
ARM: EXYNOS: Add clock support for G-Scaler
ARM: EXYNOS: Enable pinctrl driver support for EXYNOS4 device tree enabled platform
ARM: dts: Add pinctrl node entries for SAMSUNG EXYNOS4210 SoC
ARM: EXYNOS: skip wakeup interrupt setup if pinctrl driver is used
...
Diffstat (limited to 'drivers/leds/ledtrig-cpu.c')
-rw-r--r-- | drivers/leds/ledtrig-cpu.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/leds/ledtrig-cpu.c b/drivers/leds/ledtrig-cpu.c new file mode 100644 index 000000000000..b312056da14d --- /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 <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; + 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 <linus.walleij@linaro.org>"); +MODULE_AUTHOR("Bryan Wu <bryan.wu@canonical.com>"); +MODULE_DESCRIPTION("CPU LED trigger"); +MODULE_LICENSE("GPL"); |