Hi,
On 5/31/24 2:36 PM, Lee Jones wrote:
> On Thu, 09 May 2024, Hans de Goede wrote:
>
>> Add a new trigger which turns LEDs on when there is input
>> (/dev/input/event*) activity and turns them back off again after there has
>> been no activity for 5 seconds.
>>
>> This is primarily intended to control LED devices which are a backlight for
>> capacitive touch-buttons, such as e.g. the menu / home / back buttons found
>> on the bottom bezel of many somewhat older smartphones and tablets.
>>
>> This can also be used to turn on the keyboard backlight LED on input
>> events and turn the keyboard backlight off again when idle.
>>
>> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>> ---
>> Changes in v2:
>> - Add MODULE_ALIAS() for module auto-loading
>> - Stop using the led-trigger.c private trigger->led_cdevs list
>> ---
>> drivers/leds/trigger/Kconfig | 16 ++
>> drivers/leds/trigger/Makefile | 1 +
>> drivers/leds/trigger/ledtrig-input-events.c | 233 ++++++++++++++++++++
>> 3 files changed, 250 insertions(+)
>> create mode 100644 drivers/leds/trigger/ledtrig-input-events.c
>
> Looks good to me. Just one tiny nit, then it'll be good to go.
>
>> diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
>> index d11d80176fc0..809ffba0cd6a 100644
>> --- a/drivers/leds/trigger/Kconfig
>> +++ b/drivers/leds/trigger/Kconfig
>> @@ -152,4 +152,20 @@ config LEDS_TRIGGER_TTY
>>
>> When build as a module this driver will be called ledtrig-tty.
>>
>> +config LEDS_TRIGGER_INPUT_EVENTS
>> + tristate "LED Input events trigger"
>> + depends on INPUT
>> + help
>> + Turn LEDs on when there is input (/dev/input/event*) activity and turn
>> + them back off again after there has been no activity for 5 seconds.
>> +
>> + This is primarily intended to control LEDs which are a backlight for
>> + capacitive touch-buttons, such as e.g. the menu / home / back buttons
>> + found on the bottom bezel of many older smartphones and tablets.
>> +
>> + This can also be used to turn on the keyboard backlight LED on
>> + input events and turn the keyboard backlight off again when idle.
>> +
>> + When build as a module this driver will be called ledtrig-input-events.
>> +
>> endif # LEDS_TRIGGERS
>> diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile
>> index 25c4db97cdd4..f78a3077efc7 100644
>> --- a/drivers/leds/trigger/Makefile
>> +++ b/drivers/leds/trigger/Makefile
>> @@ -16,3 +16,4 @@ obj-$(CONFIG_LEDS_TRIGGER_NETDEV) += ledtrig-netdev.o
>> obj-$(CONFIG_LEDS_TRIGGER_PATTERN) += ledtrig-pattern.o
>> obj-$(CONFIG_LEDS_TRIGGER_AUDIO) += ledtrig-audio.o
>> obj-$(CONFIG_LEDS_TRIGGER_TTY) += ledtrig-tty.o
>> +obj-$(CONFIG_LEDS_TRIGGER_INPUT_EVENTS) += ledtrig-input-events.o
>> diff --git a/drivers/leds/trigger/ledtrig-input-events.c b/drivers/leds/trigger/ledtrig-input-events.c
>> new file mode 100644
>> index 000000000000..f076476bbb77
>> --- /dev/null
>> +++ b/drivers/leds/trigger/ledtrig-input-events.c
>> @@ -0,0 +1,233 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Input Events LED trigger
>> + *
>> + * Copyright (C) 2024 Hans de Goede <hansg@xxxxxxxxxx>
>> + * Partially based on Atsushi Nemoto's ledtrig-heartbeat.c.
>> + */
>> +
>> +#include <linux/input.h>
>> +#include <linux/jiffies.h>
>> +#include <linux/leds.h>
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/workqueue.h>
>> +#include "../leds.h"
>> +
>> +#define DEFAULT_LED_OFF_DELAY_MS 5000
>> +
>> +struct input_events_data {
>> + struct input_handler handler;
>> + struct delayed_work work;
>> + spinlock_t lock;
>> + struct led_classdev *led_cdev;
>> + int led_cdev_saved_flags;
>> + /* To avoid repeatedly setting the brightness while there are events */
>> + bool led_on;
>> + unsigned long led_off_time;
>> + unsigned long led_off_delay;
>> +};
>> +
>> +static void led_input_events_work(struct work_struct *work)
>> +{
>> + struct input_events_data *data =
>> + container_of(work, struct input_events_data, work.work);
>> +
>> + spin_lock_irq(&data->lock);
>> +
>> + /*
>> + * This time_after_eq() check avoids a race where this work starts
>> + * running before a new event pushed led_off_time back.
>> + */
>> + if (time_after_eq(jiffies, data->led_off_time)) {
>> + led_set_brightness_nosleep(data->led_cdev, LED_OFF);
>> + data->led_on = false;
>> + }
>> +
>> + spin_unlock_irq(&data->lock);
>> +}
>> +
>> +static ssize_t delay_show(struct device *dev, struct device_attribute *attr, char *buf)
>> +{
>> + struct input_events_data *input_events_data = led_trigger_get_drvdata(dev);
>> +
>> + return sysfs_emit(buf, "%lu\n", input_events_data->led_off_delay);
>> +}
>> +
>> +static ssize_t delay_store(struct device *dev, struct device_attribute *attr,
>> + const char *buf, size_t size)
>> +{
>> + struct input_events_data *input_events_data = led_trigger_get_drvdata(dev);
>> + unsigned long delay;
>> + int ret;
>> +
>> + ret = kstrtoul(buf, 0, &delay);
>> + if (ret)
>> + return ret;
>> +
>> + /* Clamp between 0.5 and 1000 seconds */
>> + delay = clamp_val(delay, 500UL, 1000000UL);
>> + input_events_data->led_off_delay = msecs_to_jiffies(delay);
>> +
>> + return size;
>> +}
>> +
>> +static DEVICE_ATTR_RW(delay);
>> +
>> +static struct attribute *input_events_led_attrs[] = {
>> + &dev_attr_delay.attr,
>> + NULL
>> +};
>> +ATTRIBUTE_GROUPS(input_events_led);
>> +
>> +static void input_events_event(struct input_handle *handle, unsigned int type,
>> + unsigned int code, int val)
>> +{
>> + struct input_events_data *data =
>> + container_of(handle->handler, struct input_events_data, handler);
>> + unsigned long led_off_delay = READ_ONCE(data->led_off_delay);
>> + struct led_classdev *led_cdev = data->led_cdev;
>> + unsigned long flags;
>> +
>> + if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags))
>> + led_cdev->blink_brightness = led_cdev->new_blink_brightness;
>> +
>> + spin_lock_irqsave(&data->lock, flags);
>> +
>> + if (!data->led_on) {
>> + led_set_brightness_nosleep(led_cdev, led_cdev->blink_brightness);
>> + data->led_on = true;
>> + }
>> + data->led_off_time = jiffies + led_off_delay;
>> +
>> + spin_unlock_irqrestore(&data->lock, flags);
>> +
>> + mod_delayed_work(system_wq, &data->work, led_off_delay);
>> +}
>> +
>> +static int input_events_connect(struct input_handler *handler, struct input_dev *dev,
>> + const struct input_device_id *id)
>> +{
>> + struct input_handle *handle;
>> + int ret;
>> +
>> + handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
>
> Nit: sizeof(*handle)?
Ack, thank you for the review. I'll rebase this on top of v6.10-rc1
and send out a v3 with the nit fixed.
Regards,
Hans
>
>> + if (!handle)
>> + return -ENOMEM;
>> +
>> + handle->dev = dev;
>> + handle->handler = handler;
>> + handle->name = "input-events";
>> +
>> + ret = input_register_handle(handle);
>> + if (ret)
>> + goto err_free_handle;
>> +
>> + ret = input_open_device(handle);
>> + if (ret)
>> + goto err_unregister_handle;
>> +
>> + return 0;
>> +
>> +err_unregister_handle:
>> + input_unregister_handle(handle);
>> +err_free_handle:
>> + kfree(handle);
>> + return ret;
>> +}
>> +
>> +static void input_events_disconnect(struct input_handle *handle)
>> +{
>> + input_close_device(handle);
>> + input_unregister_handle(handle);
>> + kfree(handle);
>> +}
>> +
>> +static const struct input_device_id input_events_ids[] = {
>> + {
>> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
>> + .evbit = { BIT_MASK(EV_KEY) },
>> + },
>> + {
>> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
>> + .evbit = { BIT_MASK(EV_REL) },
>> + },
>> + {
>> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
>> + .evbit = { BIT_MASK(EV_ABS) },
>> + },
>> + { }
>> +};
>> +
>> +static int input_events_activate(struct led_classdev *led_cdev)
>> +{
>> + struct input_events_data *data;
>> + int ret;
>> +
>> + data = kzalloc(sizeof(*data), GFP_KERNEL);
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + data->handler.name = "input-events";
>> + data->handler.event = input_events_event;
>> + data->handler.connect = input_events_connect;
>> + data->handler.disconnect = input_events_disconnect;
>> + data->handler.id_table = input_events_ids;
>> +
>> + INIT_DELAYED_WORK(&data->work, led_input_events_work);
>> + spin_lock_init(&data->lock);
>> +
>> + data->led_cdev = led_cdev;
>> + data->led_cdev_saved_flags = led_cdev->flags;
>> + data->led_off_delay = msecs_to_jiffies(DEFAULT_LED_OFF_DELAY_MS);
>> +
>> + /*
>> + * Use led_cdev->blink_brightness + LED_BLINK_SW flag so that sysfs
>> + * brightness writes will change led_cdev->new_blink_brightness for
>> + * configuring the on state brightness (like ledtrig-heartbeat).
>> + */
>> + if (!led_cdev->blink_brightness)
>> + led_cdev->blink_brightness = led_cdev->max_brightness;
>> +
>> + /* Start with LED off */
>> + led_set_brightness_nosleep(data->led_cdev, LED_OFF);
>> +
>> + ret = input_register_handler(&data->handler);
>> + if (ret) {
>> + kfree(data);
>> + return ret;
>> + }
>> +
>> + set_bit(LED_BLINK_SW, &led_cdev->work_flags);
>> +
>> + /* Turn LED off during suspend, original flags are restored on deactivate() */
>> + led_cdev->flags |= LED_CORE_SUSPENDRESUME;
>> +
>> + led_set_trigger_data(led_cdev, data);
>> + return 0;
>> +}
>> +
>> +static void input_events_deactivate(struct led_classdev *led_cdev)
>> +{
>> + struct input_events_data *data = led_get_trigger_data(led_cdev);
>> +
>> + led_cdev->flags = data->led_cdev_saved_flags;
>> + clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
>> + input_unregister_handler(&data->handler);
>> + cancel_delayed_work_sync(&data->work);
>> + kfree(data);
>> +}
>> +
>> +static struct led_trigger input_events_led_trigger = {
>> + .name = "input-events",
>> + .activate = input_events_activate,
>> + .deactivate = input_events_deactivate,
>> + .groups = input_events_led_groups,
>> +};
>> +module_led_trigger(input_events_led_trigger);
>> +
>> +MODULE_AUTHOR("Hans de Goede <hansg@xxxxxxxxxx>");
>> +MODULE_DESCRIPTION("Input Events LED trigger");
>> +MODULE_LICENSE("GPL");
>> +MODULE_ALIAS("ledtrig:input-events");
>> --
>> 2.44.0
>>
>
