The patch adds LED triggers for indicating an activity on a selected device. The drivers that intend to use triggers need to register respective devices using ledtrig_dev_add(). Triggers are generated by explicitly calling ledtrig_dev_activity().
Signed-off-by: Maciek Borzecki <[email protected]> --- drivers/leds/trigger/Kconfig | 8 ++ drivers/leds/trigger/Makefile | 1 + drivers/leds/trigger/ledtrig-device.c | 185 ++++++++++++++++++++++++++++++++++ include/linux/leds.h | 10 ++ 4 files changed, 204 insertions(+) create mode 100644 drivers/leds/trigger/ledtrig-device.c diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig index 5bda6a9b56bbd90b4a3749f87bc0c6fda8dd5034..c6ecfbd7c0876f21688140aa9afc7eb5b9fec3a2 100644 --- a/drivers/leds/trigger/Kconfig +++ b/drivers/leds/trigger/Kconfig @@ -108,4 +108,12 @@ config LEDS_TRIGGER_CAMERA This enables direct flash/torch on/off by the driver, kernel space. If unsure, say Y. +config LEDS_TRIGGER_DEVICE + bool "LED Device Activity Trigger" + depends on LEDS_TRIGGERS + help + This allows LEDs to be triggered by an actvity on a selected + device. + If unsure, say Y. + endif # LEDS_TRIGGERS diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile index 1abf48dacf7ebfcfb8208f7ae7bdf29d7c11ba32..86beeacd5403afc163873d7c3f817ee082b64e04 100644 --- a/drivers/leds/trigger/Makefile +++ b/drivers/leds/trigger/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_LEDS_TRIGGER_CPU) += ledtrig-cpu.o obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON) += ledtrig-default-on.o obj-$(CONFIG_LEDS_TRIGGER_TRANSIENT) += ledtrig-transient.o obj-$(CONFIG_LEDS_TRIGGER_CAMERA) += ledtrig-camera.o +obj-$(CONFIG_LEDS_TRIGGER_DEVICE) += ledtrig-device.o diff --git a/drivers/leds/trigger/ledtrig-device.c b/drivers/leds/trigger/ledtrig-device.c new file mode 100644 index 0000000000000000000000000000000000000000..dbb8d7d2b4a0258149c581a040c416d412d9ceeb --- /dev/null +++ b/drivers/leds/trigger/ledtrig-device.c @@ -0,0 +1,185 @@ +/* + * LED Device Activity Trigger + * + * Copyright 2015 Maciej Borzecki <[email protected]> + * + * 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/init.h> +#include <linux/leds.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/rwsem.h> +#include <linux/kdev_t.h> + +#define BLINK_DELAY 30 +static unsigned long blink_delay = BLINK_DELAY; + +static DECLARE_RWSEM(devs_list_lock); +static LIST_HEAD(devs_list); + +#define MAX_NAME_LEN 20 + +struct ledtrig_dev_data { + char name[MAX_NAME_LEN]; + dev_t dev; + struct led_trigger *trig; + struct list_head node; +}; + +/** + * ledtrig_dev_activity - signal activity on device + * @dev: device + * + * Fires a trigger assigned to @dev device. + */ +void ledtrig_dev_activity(dev_t dev) +{ + struct ledtrig_dev_data *dev_trig; + + if (!down_read_trylock(&devs_list_lock)) + return; + + list_for_each_entry(dev_trig, &devs_list, node) { + if (dev_trig->dev == dev) { + led_trigger_blink_oneshot(dev_trig->trig, + &blink_delay, + &blink_delay, + 0); + break; + } + } + up_read(&devs_list_lock); +} +EXPORT_SYMBOL(ledtrig_dev_activity); + +static struct ledtrig_dev_data *ledtrig_dev_new(dev_t dev) +{ + struct ledtrig_dev_data *dev_trig; + + dev_trig = kzalloc(sizeof(*dev_trig), GFP_KERNEL); + if (!dev_trig) + return NULL; + + INIT_LIST_HEAD(&dev_trig->node); + dev_trig->dev = dev; + snprintf(dev_trig->name, sizeof(dev_trig->name), + "dev-%u:%u", MAJOR(dev), MINOR(dev)); + + return dev_trig; +} + +static void ledtrig_dev_release(struct ledtrig_dev_data *dev_trig) +{ + led_trigger_unregister_simple(dev_trig->trig); + + kfree(dev_trig); +} + +/** + * ledtrig_dev_add - add a trigger for device + * @dev: device for which the trigger is to be added + * + * Create and register a new trigger for device @dev. The trigger will + * show up as dev-<major>:<minor> in the list of avaialble LED + * triggers. + */ +void ledtrig_dev_add(dev_t dev) +{ + int found = 0; + struct ledtrig_dev_data *new_dev_trig; + struct ledtrig_dev_data *dev_trig; + + new_dev_trig = ledtrig_dev_new(dev); + if (!new_dev_trig) + return; + + down_write(&devs_list_lock); + list_for_each_entry(dev_trig, &devs_list, node) { + if (dev_trig->dev == dev) { + found = 1; + break; + } + } + if (!found) + list_add(&new_dev_trig->node, &devs_list); + up_write(&devs_list_lock); + + if (!found) + /* register with led triggers */ + led_trigger_register_simple(new_dev_trig->name, + &new_dev_trig->trig); + else + kfree(new_dev_trig); +} +EXPORT_SYMBOL(ledtrig_dev_add); + +/** + * ledtrig_dev_del - delete a trigger + * @dev: device for which to delete a trigger + */ +void ledtrig_dev_del(dev_t dev) +{ + + struct ledtrig_dev_data *dev_trig; + + down_write(&devs_list_lock); + list_for_each_entry(dev_trig, &devs_list, node) { + if (dev_trig->dev == dev) { + /* remove from devs list */ + list_del(&dev_trig->node); + + /* unregister & release data */ + ledtrig_dev_release(dev_trig); + break; + } + } + up_write(&devs_list_lock); + +} +EXPORT_SYMBOL(ledtrig_dev_del); + +static void ledtrig_dev_remove_all(void) +{ + struct list_head *en; + + down_write(&devs_list_lock); + list_for_each(en, &devs_list) { + struct list_head *prev = en->prev; + struct ledtrig_dev_data *dev_trig; + + dev_trig = list_entry(en, struct ledtrig_dev_data, + node); + /* remove from list */ + list_del(en); + + /* unregister & release data */ + ledtrig_dev_release(dev_trig); + + /* and go back */ + en = prev; + } + up_write(&devs_list_lock); +} + +static int __init ledtrig_dev_init(void) +{ + return 0; +} + +static void __exit ledtrig_dev_exit(void) +{ + ledtrig_dev_remove_all(); +} + +module_init(ledtrig_dev_init); +module_exit(ledtrig_dev_exit); + +MODULE_AUTHOR("Maciej Borzecki <[email protected]>"); +MODULE_DESCRIPTION("LED Device Activity Trigger"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/leds.h b/include/linux/leds.h index b122eeafb5dc17b8a8b1a1852dc1c420ecf0f8d2..e487d5b2ac556bdb2f1525d8b5e84df0c245d4c9 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -369,4 +369,14 @@ static inline void ledtrig_cpu(enum cpu_led_event evt) } #endif +#ifdef CONFIG_LEDS_TRIGGER_DEVICE +extern void ledtrig_dev_add(dev_t dev); +extern void ledtrig_dev_del(dev_t dev); +extern void ledtrig_dev_activity(dev_t dev); +#else +static inline void ledtrig_dev_add(dev_t dev) {} +static inline void ledtrig_dev_del(dev_t dev) {} +static inline void ledtrig_dev_activity(dev_t dev) {} +#endif + #endif /* __LINUX_LEDS_H_INCLUDED */ -- 2.6.0 -- To unsubscribe from this list: send the line "unsubscribe linux-leds" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
