[PATCH] Route keyboard LEDs through the generic LEDs layer.
Pali Rohár
pali.rohar at gmail.com
Tue Apr 1 00:02:45 PDT 2014
2014-03-31 14:23 GMT+02:00 Samuel Thibault <samuel.thibault at ens-lyon.org>:
> This permits to reassign keyboard LEDs to something else than keyboard "leds"
> state, by adding keyboard led and modifier triggers connected to a series
> of VT input LEDs, themselves connected to VT input triggers, which
> per-input device LEDs use by default. Userland can thus easily change the LED
> behavior of (a priori) all input devices, or of particular input devices.
>
> This also permits to fix #7063 from userland by using a modifier to implement
> proper CapsLock behavior and have the keyboard caps lock led show that modifier
> state.
>
> [ebroder at mokafive.com: Rebased to 3.2-rc1 or so, cleaned up some includes, and fixed some constants]
> [blogic at openwrt.org: CONFIG_INPUT_LEDS stubs should be static inline]
> [akpm at linux-foundation.org: remove unneeded `extern', fix comment layout]
> Signed-off-by: Samuel Thibault <samuel.thibault at ens-lyon.org>
> Signed-off-by: Evan Broder <evan at ebroder.net>
> Reviewed-by: David Herrmann <dh.herrmann at gmail.com>
> Tested-by: Pavel Machek <pavel at ucw.cz>
> Acked-by: Peter Korsgaard <jacmet at sunsite.dk>
> Signed-off-by: John Crispin <blogic at openwrt.org>
> Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
> ---
> Changed in this version:
> - fixes symbol dependencies between input.c and leds.c (notably
> input_led_connect/disconnect) by stuffing them together in input.ko.
> - documents the new leds field of struct input_dev.
>
> --- a/Documentation/leds/leds-class.txt
> +++ b/Documentation/leds/leds-class.txt
> @@ -2,9 +2,6 @@
> LED handling under Linux
> ========================
>
> -If you're reading this and thinking about keyboard leds, these are
> -handled by the input subsystem and the led class is *not* needed.
> -
> In its simplest form, the LED class just allows control of LEDs from
> userspace. LEDs appear in /sys/class/leds/. The maximum brightness of the
> LED is defined in max_brightness file. The brightness file will set the brightness
> --- a/drivers/input/input.c
> +++ b/drivers/input/input.c
> @@ -708,6 +708,9 @@ static void input_disconnect_device(stru
> handle->open = 0;
>
> spin_unlock_irq(&dev->event_lock);
> +
> + if (is_event_supported(EV_LED, dev->evbit, EV_MAX))
> + input_led_disconnect(dev);
> }
>
> /**
> @@ -2134,6 +2137,9 @@ int input_register_device(struct input_d
>
> list_add_tail(&dev->node, &input_dev_list);
>
> + if (is_event_supported(EV_LED, dev->evbit, EV_MAX))
> + input_led_connect(dev);
> +
> list_for_each_entry(handler, &input_handler_list, node)
> input_attach_handler(dev, handler);
>
> --- a/drivers/input/Kconfig
> +++ b/drivers/input/Kconfig
> @@ -178,6 +178,15 @@ comment "Input Device Drivers"
>
> source "drivers/input/keyboard/Kconfig"
>
> +config INPUT_LEDS
> + bool "LED Support"
> + depends on LEDS_CLASS = INPUT || LEDS_CLASS = y
> + select LEDS_TRIGGERS
> + default y
> + help
> + This option enables support for LEDs on keyboards managed
> + by the input layer.
> +
> source "drivers/input/mouse/Kconfig"
>
> source "drivers/input/joystick/Kconfig"
> --- a/drivers/input/Makefile
> +++ b/drivers/input/Makefile
> @@ -6,6 +6,9 @@
>
> obj-$(CONFIG_INPUT) += input-core.o
> input-core-y := input.o input-compat.o input-mt.o ff-core.o
> +ifeq ($(CONFIG_INPUT_LEDS),y)
> +input-core-y += leds.o
> +endif
>
> obj-$(CONFIG_INPUT_FF_MEMLESS) += ff-memless.o
> obj-$(CONFIG_INPUT_POLLDEV) += input-polldev.o
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -11,9 +11,6 @@ menuconfig NEW_LEDS
> Say Y to enable Linux LED support. This allows control of supported
> LEDs from both userspace and optionally, by kernel events (triggers).
>
> - This is not related to standard keyboard LEDs which are controlled
> - via the input system.
> -
> if NEW_LEDS
>
> config LEDS_CLASS
> --- a/drivers/tty/Kconfig
> +++ b/drivers/tty/Kconfig
> @@ -13,6 +13,10 @@ config VT
> bool "Virtual terminal" if EXPERT
> depends on !S390 && !UML
> select INPUT
> + select NEW_LEDS
> + select LEDS_CLASS
> + select LEDS_TRIGGERS
> + select INPUT_LEDS
> default y
> ---help---
> If you say Y here, you will get support for terminal devices with
> --- a/drivers/tty/vt/keyboard.c
> +++ b/drivers/tty/vt/keyboard.c
> @@ -33,6 +33,7 @@
> #include <linux/string.h>
> #include <linux/init.h>
> #include <linux/slab.h>
> +#include <linux/leds.h>
>
> #include <linux/kbd_kern.h>
> #include <linux/kbd_diacr.h>
> @@ -130,6 +131,7 @@ static char rep; /* flag telling cha
> static int shift_state = 0;
>
> static unsigned char ledstate = 0xff; /* undefined */
> +static unsigned char lockstate = 0xff; /* undefined */
> static unsigned char ledioctl;
>
> /*
> @@ -961,6 +963,41 @@ static void k_brl(struct vc_data *vc, un
> }
> }
>
> +/* We route VT keyboard "leds" through triggers */
> +static void kbd_ledstate_trigger_activate(struct led_classdev *cdev);
> +
> +static struct led_trigger ledtrig_ledstate[] = {
> +#define DEFINE_LEDSTATE_TRIGGER(kbd_led, nam) \
> + [kbd_led] = { \
> + .name = nam, \
> + .activate = kbd_ledstate_trigger_activate, \
> + }
> + DEFINE_LEDSTATE_TRIGGER(VC_SCROLLOCK, "kbd-scrollock"),
> + DEFINE_LEDSTATE_TRIGGER(VC_NUMLOCK, "kbd-numlock"),
> + DEFINE_LEDSTATE_TRIGGER(VC_CAPSLOCK, "kbd-capslock"),
> + DEFINE_LEDSTATE_TRIGGER(VC_KANALOCK, "kbd-kanalock"),
> +#undef DEFINE_LEDSTATE_TRIGGER
> +};
> +
> +static void kbd_lockstate_trigger_activate(struct led_classdev *cdev);
> +
> +static struct led_trigger ledtrig_lockstate[] = {
> +#define DEFINE_LOCKSTATE_TRIGGER(kbd_led, nam) \
> + [kbd_led] = { \
> + .name = nam, \
> + .activate = kbd_lockstate_trigger_activate, \
> + }
> + DEFINE_LOCKSTATE_TRIGGER(VC_SHIFTLOCK, "kbd-shiftlock"),
> + DEFINE_LOCKSTATE_TRIGGER(VC_ALTGRLOCK, "kbd-altgrlock"),
> + DEFINE_LOCKSTATE_TRIGGER(VC_CTRLLOCK, "kbd-ctrllock"),
> + DEFINE_LOCKSTATE_TRIGGER(VC_ALTLOCK, "kbd-altlock"),
> + DEFINE_LOCKSTATE_TRIGGER(VC_SHIFTLLOCK, "kbd-shiftllock"),
> + DEFINE_LOCKSTATE_TRIGGER(VC_SHIFTRLOCK, "kbd-shiftrlock"),
> + DEFINE_LOCKSTATE_TRIGGER(VC_CTRLLLOCK, "kbd-ctrlllock"),
> + DEFINE_LOCKSTATE_TRIGGER(VC_CTRLRLOCK, "kbd-ctrlrlock"),
> +#undef DEFINE_LOCKSTATE_TRIGGER
> +};
> +
> /*
> * The leds display either (i) the status of NumLock, CapsLock, ScrollLock,
> * or (ii) whatever pattern of lights people want to show using KDSETLED,
> @@ -995,18 +1032,25 @@ static inline unsigned char getleds(void
> return kbd->ledflagstate;
> }
>
> -static int kbd_update_leds_helper(struct input_handle *handle, void *data)
> +/* Called on trigger connection, to set initial state */
> +static void kbd_ledstate_trigger_activate(struct led_classdev *cdev)
> {
> - unsigned char leds = *(unsigned char *)data;
> + struct led_trigger *trigger = cdev->trigger;
> + int led = trigger - ledtrig_ledstate;
>
> - if (test_bit(EV_LED, handle->dev->evbit)) {
> - input_inject_event(handle, EV_LED, LED_SCROLLL, !!(leds & 0x01));
> - input_inject_event(handle, EV_LED, LED_NUML, !!(leds & 0x02));
> - input_inject_event(handle, EV_LED, LED_CAPSL, !!(leds & 0x04));
> - input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
> - }
> + tasklet_disable(&keyboard_tasklet);
> + led_trigger_event(trigger, ledstate & (1 << led) ? LED_FULL : LED_OFF);
> + tasklet_enable(&keyboard_tasklet);
> +}
>
> - return 0;
> +static void kbd_lockstate_trigger_activate(struct led_classdev *cdev)
> +{
> + struct led_trigger *trigger = cdev->trigger;
> + int led = trigger - ledtrig_lockstate;
> +
> + tasklet_disable(&keyboard_tasklet);
> + led_trigger_event(trigger, lockstate & (1 << led) ? LED_FULL : LED_OFF);
> + tasklet_enable(&keyboard_tasklet);
> }
>
> /**
> @@ -1095,16 +1139,29 @@ static void kbd_bh(unsigned long dummy)
> {
> unsigned char leds;
> unsigned long flags;
> -
> + int i;
> +
> spin_lock_irqsave(&led_lock, flags);
> leds = getleds();
> spin_unlock_irqrestore(&led_lock, flags);
>
> if (leds != ledstate) {
> - input_handler_for_each_handle(&kbd_handler, &leds,
> - kbd_update_leds_helper);
> + for (i = 0; i < ARRAY_SIZE(ledtrig_ledstate); i++)
> + if ((leds ^ ledstate) & (1 << i))
> + led_trigger_event(&ledtrig_ledstate[i],
> + leds & (1 << i)
> + ? LED_FULL : LED_OFF);
> ledstate = leds;
> }
> +
> + if (kbd->lockstate != lockstate) {
> + for (i = 0; i < ARRAY_SIZE(ledtrig_lockstate); i++)
> + if ((kbd->lockstate ^ lockstate) & (1 << i))
> + led_trigger_event(&ledtrig_lockstate[i],
> + kbd->lockstate & (1 << i)
> + ? LED_FULL : LED_OFF);
> + lockstate = kbd->lockstate;
> + }
> }
>
> DECLARE_TASKLET_DISABLED(keyboard_tasklet, kbd_bh, 0);
> @@ -1442,20 +1499,6 @@ static void kbd_disconnect(struct input_
> kfree(handle);
> }
>
> -/*
> - * Start keyboard handler on the new keyboard by refreshing LED state to
> - * match the rest of the system.
> - */
> -static void kbd_start(struct input_handle *handle)
> -{
> - tasklet_disable(&keyboard_tasklet);
> -
> - if (ledstate != 0xff)
> - kbd_update_leds_helper(handle, &ledstate);
> -
> - tasklet_enable(&keyboard_tasklet);
> -}
> -
> static const struct input_device_id kbd_ids[] = {
> {
> .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
> @@ -1477,7 +1520,6 @@ static struct input_handler kbd_handler
> .match = kbd_match,
> .connect = kbd_connect,
> .disconnect = kbd_disconnect,
> - .start = kbd_start,
> .name = "kbd",
> .id_table = kbd_ids,
> };
> @@ -1501,6 +1543,20 @@ int __init kbd_init(void)
> if (error)
> return error;
>
> + for (i = 0; i < ARRAY_SIZE(ledtrig_ledstate); i++) {
> + error = led_trigger_register(&ledtrig_ledstate[i]);
> + if (error)
> + pr_err("error %d while registering trigger %s\n",
> + error, ledtrig_ledstate[i].name);
> + }
> +
> + for (i = 0; i < ARRAY_SIZE(ledtrig_lockstate); i++) {
> + error = led_trigger_register(&ledtrig_lockstate[i]);
> + if (error)
> + pr_err("error %d while registering trigger %s\n",
> + error, ledtrig_lockstate[i].name);
> + }
> +
> tasklet_enable(&keyboard_tasklet);
> tasklet_schedule(&keyboard_tasklet);
>
> --- a/include/linux/input.h
> +++ b/include/linux/input.h
> @@ -79,6 +79,7 @@ struct input_value {
> * @led: reflects current state of device's LEDs
> * @snd: reflects current state of sound effects
> * @sw: reflects current state of device's switches
> + * @leds: leds objects for the device's LEDs
> * @open: this method is called when the very first user calls
> * input_open_device(). The driver must prepare the device
> * to start generating events (start polling thread,
> @@ -164,6 +165,8 @@ struct input_dev {
> unsigned long snd[BITS_TO_LONGS(SND_CNT)];
> unsigned long sw[BITS_TO_LONGS(SW_CNT)];
>
> + struct led_classdev *leds;
> +
> int (*open)(struct input_dev *dev);
> void (*close)(struct input_dev *dev);
> int (*flush)(struct input_dev *dev, struct file *file);
> @@ -531,4 +534,22 @@ int input_ff_erase(struct input_dev *dev
> int input_ff_create_memless(struct input_dev *dev, void *data,
> int (*play_effect)(struct input_dev *, void *, struct ff_effect *));
>
> +#ifdef CONFIG_INPUT_LEDS
> +
> +int input_led_connect(struct input_dev *dev);
> +void input_led_disconnect(struct input_dev *dev);
> +
> +#else
> +
> +static inline int input_led_connect(struct input_dev *dev)
> +{
> + return 0;
> +}
> +
> +static inline void input_led_disconnect(struct input_dev *dev)
> +{
> +}
> +
> +#endif
> +
> #endif
> --- /dev/null
> +++ b/drivers/input/leds.c
> @@ -0,0 +1,249 @@
> +/*
> + * LED support for the input layer
> + *
> + * Copyright 2010-2014 Samuel Thibault <samuel.thibault at ens-lyon.org>
> + *
> + * 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/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/leds.h>
> +#include <linux/input.h>
> +
> +/*
> + * Keyboard LEDs are propagated by default like the following example:
> + *
> + * VT keyboard numlock trigger
> + * -> vt::numl VT LED
> + * -> vt-numl VT trigger
> + * -> per-device inputX::numl LED
> + *
> + * Userland can however choose the trigger for the vt::numl LED, or
> + * independently choose the trigger for any inputx::numl LED.
> + *
> + *
> + * VT LED classes and triggers are registered on-demand according to
> + * existing LED devices
> + */
> +
> +/* Handler for VT LEDs, just triggers the corresponding VT trigger. */
> +static void vt_led_set(struct led_classdev *cdev,
> + enum led_brightness brightness);
> +static struct led_classdev vt_leds[LED_CNT] = {
> +#define DEFINE_INPUT_LED(vt_led, nam, deftrig) \
> + [vt_led] = { \
> + .name = "vt::"nam, \
> + .max_brightness = 1, \
> + .brightness_set = vt_led_set, \
> + .default_trigger = deftrig, \
> + }
> +/* Default triggers for the VT LEDs just correspond to the legacy
> + * usage. */
> + DEFINE_INPUT_LED(LED_NUML, "numl", "kbd-numlock"),
> + DEFINE_INPUT_LED(LED_CAPSL, "capsl", "kbd-capslock"),
> + DEFINE_INPUT_LED(LED_SCROLLL, "scrolll", "kbd-scrollock"),
> + DEFINE_INPUT_LED(LED_COMPOSE, "compose", NULL),
> + DEFINE_INPUT_LED(LED_KANA, "kana", "kbd-kanalock"),
> + DEFINE_INPUT_LED(LED_SLEEP, "sleep", NULL),
> + DEFINE_INPUT_LED(LED_SUSPEND, "suspend", NULL),
> + DEFINE_INPUT_LED(LED_MUTE, "mute", NULL),
> + DEFINE_INPUT_LED(LED_MISC, "misc", NULL),
> + DEFINE_INPUT_LED(LED_MAIL, "mail", NULL),
> + DEFINE_INPUT_LED(LED_CHARGING, "charging", NULL),
> +};
> +static const char *const vt_led_names[LED_CNT] = {
> + [LED_NUML] = "numl",
> + [LED_CAPSL] = "capsl",
> + [LED_SCROLLL] = "scrolll",
> + [LED_COMPOSE] = "compose",
> + [LED_KANA] = "kana",
> + [LED_SLEEP] = "sleep",
> + [LED_SUSPEND] = "suspend",
> + [LED_MUTE] = "mute",
> + [LED_MISC] = "misc",
> + [LED_MAIL] = "mail",
> + [LED_CHARGING] = "charging",
> +};
> +/* Handler for hotplug initialization */
> +static void vt_led_trigger_activate(struct led_classdev *cdev);
> +/* VT triggers */
> +static struct led_trigger vt_led_triggers[LED_CNT] = {
> +#define DEFINE_INPUT_LED_TRIGGER(vt_led, nam) \
> + [vt_led] = { \
> + .name = "vt-"nam, \
> + .activate = vt_led_trigger_activate, \
> + }
> + DEFINE_INPUT_LED_TRIGGER(LED_NUML, "numl"),
> + DEFINE_INPUT_LED_TRIGGER(LED_CAPSL, "capsl"),
> + DEFINE_INPUT_LED_TRIGGER(LED_SCROLLL, "scrolll"),
> + DEFINE_INPUT_LED_TRIGGER(LED_COMPOSE, "compose"),
> + DEFINE_INPUT_LED_TRIGGER(LED_KANA, "kana"),
> + DEFINE_INPUT_LED_TRIGGER(LED_SLEEP, "sleep"),
> + DEFINE_INPUT_LED_TRIGGER(LED_SUSPEND, "suspend"),
> + DEFINE_INPUT_LED_TRIGGER(LED_MUTE, "mute"),
> + DEFINE_INPUT_LED_TRIGGER(LED_MISC, "misc"),
> + DEFINE_INPUT_LED_TRIGGER(LED_MAIL, "mail"),
> + DEFINE_INPUT_LED_TRIGGER(LED_CHARGING, "charging"),
> +};
> +
> +/* Lock for registration coherency */
> +static DEFINE_MUTEX(vt_led_registered_lock);
> +
> +/* Which VT LED classes and triggers are registered */
> +static unsigned long vt_led_registered[BITS_TO_LONGS(LED_CNT)];
> +
> +/* Number of input devices having each LED */
> +static int vt_led_references[LED_CNT];
> +
> +/* VT LED state change, tell the VT trigger. */
> +static void vt_led_set(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + int led = cdev - vt_leds;
> +
> + led_trigger_event(&vt_led_triggers[led], !!brightness);
> +}
> +
> +/* LED state change for some keyboard, notify that keyboard. */
> +static void perdevice_input_led_set(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + struct input_dev *dev;
> + struct led_classdev *leds;
> + int led;
> +
> + dev = cdev->dev->platform_data;
> + if (!dev)
> + /* Still initializing */
> + return;
> + leds = dev->leds;
> + led = cdev - leds;
> +
> + input_event(dev, EV_LED, led, !!brightness);
> + input_event(dev, EV_SYN, SYN_REPORT, 0);
> +}
> +
> +/* Keyboard hotplug, initialize its LED status */
> +static void vt_led_trigger_activate(struct led_classdev *cdev)
> +{
> + struct led_trigger *trigger = cdev->trigger;
> + int led = trigger - vt_led_triggers;
> +
> + if (cdev->brightness_set)
> + cdev->brightness_set(cdev, vt_leds[led].brightness);
> +}
> +
> +/* Free led stuff from input device, used at abortion and disconnection. */
> +static void input_led_delete(struct input_dev *dev)
> +{
> + if (dev) {
> + struct led_classdev *leds = dev->leds;
> + if (leds) {
> + int i;
> + for (i = 0; i < LED_CNT; i++)
> + kfree(leds[i].name);
> + kfree(leds);
> + dev->leds = NULL;
> + }
> + }
> +}
> +
> +/* A new input device with potential LEDs to connect. */
> +int input_led_connect(struct input_dev *dev)
> +{
> + int i, error = 0;
> + struct led_classdev *leds;
> +
> + dev->leds = leds = kcalloc(LED_CNT, sizeof(*leds), GFP_KERNEL);
> + if (!dev->leds)
> + return -ENOMEM;
> +
> + /* lazily register missing VT LEDs */
> + mutex_lock(&vt_led_registered_lock);
> + for (i = 0; i < LED_CNT; i++)
> + if (vt_leds[i].name && test_bit(i, dev->ledbit)) {
> + if (!vt_led_references[i]) {
> + led_trigger_register(&vt_led_triggers[i]);
> + /* This keyboard is first to have led i,
> + * try to register it */
> + if (!led_classdev_register(NULL, &vt_leds[i]))
> + vt_led_references[i] = 1;
> + else
> + led_trigger_unregister(&vt_led_triggers[i]);
> + } else
> + vt_led_references[i]++;
> + }
> + mutex_unlock(&vt_led_registered_lock);
> +
> + /* and register this device's LEDs */
> + for (i = 0; i < LED_CNT; i++)
> + if (vt_leds[i].name && test_bit(i, dev->ledbit)) {
> + leds[i].name = kasprintf(GFP_KERNEL, "%s::%s",
> + dev_name(&dev->dev),
> + vt_led_names[i]);
> + if (!leds[i].name) {
> + error = -ENOMEM;
> + goto err;
> + }
> + leds[i].max_brightness = 1;
> + leds[i].brightness_set = perdevice_input_led_set;
> + leds[i].default_trigger = vt_led_triggers[i].name;
> + }
> +
> + /* No issue so far, we can register for real. */
> + for (i = 0; i < LED_CNT; i++)
> + if (leds[i].name) {
> + led_classdev_register(&dev->dev, &leds[i]);
> + leds[i].dev->platform_data = dev;
> + perdevice_input_led_set(&leds[i],
> + vt_leds[i].brightness);
> + }
> +
> + return 0;
> +
> +err:
> + input_led_delete(dev);
> + return error;
> +}
> +
> +/*
> + * Disconnected input device. Clean it, and deregister now-useless VT LEDs
> + * and triggers.
> + */
> +void input_led_disconnect(struct input_dev *dev)
> +{
> + int i;
> + struct led_classdev *leds = dev->leds;
> +
> + for (i = 0; i < LED_CNT; i++)
> + if (leds[i].name)
> + led_classdev_unregister(&leds[i]);
> +
> + input_led_delete(dev);
> +
> + mutex_lock(&vt_led_registered_lock);
> + for (i = 0; i < LED_CNT; i++) {
> + if (!vt_leds[i].name || !test_bit(i, dev->ledbit))
> + continue;
> +
> + vt_led_references[i]--;
> + if (vt_led_references[i]) {
> + /* Still some devices needing it */
> + continue;
> + }
> +
> + led_classdev_unregister(&vt_leds[i]);
> + led_trigger_unregister(&vt_led_triggers[i]);
> + clear_bit(i, vt_led_registered);
> + }
> + mutex_unlock(&vt_led_registered_lock);
> +}
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("User LED support for input layer");
> +MODULE_AUTHOR("Samuel Thibault <samuel.thibault at ens-lyon.org>");
>
Dmitry, can you review this patch and include it into 3.15?
--
Pali Rohár
pali.rohar at gmail.com
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