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From: Samuel Thibault on 10 Mar 2010 08:40
Route keyboard LEDs through the generic LEDs layer.

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 global input LEDs, themselves connected to global 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.

Signed-off-by: Samuel Thibault <samuel.thibault(a)ens-lyon.org>
---

Hello,

Here is a fifth version

Differences from the fourth version:
- use the platform_data field of the device struct instead of adding a
private field to struct led_classdev.
- fix using input led triggers for non-input leds.

Difference from the third version:
- creates LEDs for each input device.
- creates a global LED trigger connected to the global LED, that
per-device LEDs use by default.
- properly initializes LED state on trigger and input device connection.

Difference between third and second:
- only input LEDs actually available on devices are registered.

Difference between second and first:
- rebase on 2.6.33, fix locking issues.

Samuel

diff -ur linux-2.6.33-orig/Documentation/leds-class.txt linux-2.6.33-perso/Documentation/leds-class.txt
--- linux-2.6.33-orig/Documentation/leds-class.txt 2009-12-03 13:41:42.000000000 +0100
+++ linux-2.6.33-perso/Documentation/leds-class.txt 2010-02-25 01:45:28.000000000 +0100
@@ -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
diff -ur linux-2.6.33-orig/drivers/char/keyboard.c linux-2.6.33-perso/drivers/char/keyboard.c
--- linux-2.6.33-orig/drivers/char/keyboard.c 2010-02-25 01:41:19.000000000 +0100
+++ linux-2.6.33-perso/drivers/char/keyboard.c 2010-03-07 20:03:37.000000000 +0100
@@ -34,6 +34,7 @@
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/irq.h>
+#include <linux/leds.h>

#include <linux/kbd_kern.h>
#include <linux/kbd_diacr.h>
@@ -139,6 +140,9 @@
static char rep; /* flag telling character repeat */

static unsigned char ledstate = 0xff; /* undefined */
+#ifdef CONFIG_LEDS_INPUT
+static unsigned char lockstate = 0xff; /* undefined */
+#endif
static unsigned char ledioctl;

static struct ledptr {
@@ -971,6 +975,35 @@
}
}

+#ifdef CONFIG_LEDS_INPUT
+/* When input-based leds are enabled, we route 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, "scrollock"),
+ DEFINE_LEDSTATE_TRIGGER(VC_NUMLOCK, "numlock"),
+ DEFINE_LEDSTATE_TRIGGER(VC_CAPSLOCK, "capslock"),
+ DEFINE_LEDSTATE_TRIGGER(VC_KANALOCK, "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, "shiftlock"),
+ DEFINE_LOCKSTATE_TRIGGER(VC_ALTGRLOCK, "altgrlock"),
+ DEFINE_LOCKSTATE_TRIGGER(VC_CTRLLOCK, "ctrllock"),
+ DEFINE_LOCKSTATE_TRIGGER(VC_ALTLOCK, "altlock"),
+ DEFINE_LOCKSTATE_TRIGGER(VC_SHIFTLLOCK, "shiftllock"),
+ DEFINE_LOCKSTATE_TRIGGER(VC_SHIFTRLOCK, "shiftrlock"),
+ DEFINE_LOCKSTATE_TRIGGER(VC_CTRLLLOCK, "ctrlllock"),
+ DEFINE_LOCKSTATE_TRIGGER(VC_CTRLRLOCK, "ctrlrlock"),
+#undef DEFINE_LOCKSTATE_TRIGGER
+};
+#endif
+
/*
* The leds display either (i) the status of NumLock, CapsLock, ScrollLock,
* or (ii) whatever pattern of lights people want to show using KDSETLED,
@@ -1014,19 +1047,44 @@
return leds;
}

+#ifdef CONFIG_LEDS_INPUT
+/* Called on trigger connection, to set initial state */
+static void kbd_ledstate_trigger_activate(struct led_classdev *cdev)
+{
+ struct led_trigger *trigger = cdev->trigger;
+ int led = trigger - ledtrig_ledstate;
+
+ tasklet_disable(&keyboard_tasklet);
+ led_trigger_event(trigger, ledstate & (1 << led) ? INT_MAX : LED_OFF);
+ tasklet_enable(&keyboard_tasklet);
+}
+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) ? INT_MAX : LED_OFF);
+ tasklet_enable(&keyboard_tasklet);
+}
+#else
static int kbd_update_leds_helper(struct input_handle *handle, void *data)
{
unsigned char leds = *(unsigned char *)data;

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_LED, LED_SCROLLL,
+ !!(leds & VC_SCROLLOCK));
+ input_inject_event(handle, EV_LED, LED_NUML,
+ !!(leds & VC_NUMLOCK));
+ input_inject_event(handle, EV_LED, LED_CAPSL,
+ !!(leds & VC_CAPSLOCK));
input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
}

return 0;
}
+#endif

/*
* This is the tasklet that updates LED state on all keyboards
@@ -1040,10 +1098,31 @@
unsigned char leds = getleds();

if (leds != ledstate) {
+#ifdef CONFIG_LEDS_INPUT
+ int i;
+ for (i = 0; i < ARRAY_SIZE(ledtrig_ledstate); i++)
+ if ((leds ^ ledstate) & (1 << i))
+ led_trigger_event(&ledtrig_ledstate[i],
+ leds & (1 << i)
+ ? INT_MAX : LED_OFF);
+#else
input_handler_for_each_handle(&kbd_handler, &leds,
kbd_update_leds_helper);
+#endif
ledstate = leds;
}
+
+#ifdef CONFIG_LEDS_INPUT
+ if (kbd->lockstate != lockstate) {
+ int i;
+ 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)
+ ? INT_MAX : LED_OFF);
+ lockstate = kbd->lockstate;
+ }
+#endif
}

DECLARE_TASKLET_DISABLED(keyboard_tasklet, kbd_bh, 0);
@@ -1380,6 +1459,7 @@
kfree(handle);
}

+#ifndef CONFIG_LEDS_INPUT
/*
* Start keyboard handler on the new keyboard by refreshing LED state to
* match the rest of the system.
@@ -1393,6 +1473,7 @@

tasklet_enable(&keyboard_tasklet);
}
+#endif

static const struct input_device_id kbd_ids[] = {
{
@@ -1414,7 +1495,9 @@
.event = kbd_event,
.connect = kbd_connect,
.disconnect = kbd_disconnect,
+#ifndef CONFIG_LEDS_INPUT
.start = kbd_start,
+#endif
.name = "kbd",
.id_table = kbd_ids,
};
@@ -1441,5 +1524,12 @@
tasklet_enable(&keyboard_tasklet);
tasklet_schedule(&keyboard_tasklet);

+#ifdef CONFIG_LEDS_INPUT
+ for (i = 0; i < ARRAY_SIZE(ledtrig_ledstate); i++)
+ led_trigger_register(&ledtrig_ledstate[i]);
+ for (i = 0; i < ARRAY_SIZE(ledtrig_lockstate); i++)
+ led_trigger_register(&ledtrig_lockstate[i]);
+#endif
+
return 0;
}
diff -ur linux-2.6.33-orig/drivers/leds/Kconfig linux-2.6.33-perso/drivers/leds/Kconfig
--- linux-2.6.33-orig/drivers/leds/Kconfig 2010-02-25 01:41:27.000000000 +0100
+++ linux-2.6.33-perso/drivers/leds/Kconfig 2010-03-07 15:38:11.000000000 +0100
@@ -4,9 +4,6 @@
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
@@ -17,6 +14,14 @@

comment "LED drivers"

+config LEDS_INPUT
+ tristate "LED Support using input keyboards"
+ depends on LEDS_CLASS
+ select LEDS_TRIGGERS
+ help
+ This option enables support for the LEDs on keyboard managed
+ by the input layer.
+
config LEDS_ATMEL_PWM
tristate "LED Support using Atmel PWM outputs"
depends on LEDS_CLASS && ATMEL_PWM
diff -ur linux-2.6.33-orig/drivers/leds/leds-input.c linux-2.6.33-perso/drivers/leds/leds-input.c
--- linux-2.6.33-orig/drivers/leds/leds-input.c 2010-02-21 04:13:41.000000000 +0100
+++ linux-2.6.33-perso/drivers/leds/leds-input.c 2010-03-10 11:59:12.000000000 +0100
@@ -0,0 +1,307 @@
+/*
+ * LED support for the input layer
+ *
+ * Copyright 2010 Samuel Thibault <samuel.thibault(a)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/init.h>
+#include <linux/leds.h>
+#include <linux/input.h>
+
+#include "leds.h"
+
+/*
+ * Keyboard LEDs are propagated by default like the following example:
+ *
+ * keyboard numlock trigger
+ * -> input::numl global input LED
+ * -> input-numl global input trigger
+ * -> per-device <device>-input::numl LED
+ *
+ * Userland can however choose the trigger for the input::numl LED, or
+ * independently choose the trigger for any input-<device>::numl LED.
+ */
+
+/* Global LED classes and triggers are registered on-demand according to
+ * existing devices */
+
+/* Handler for global input LEDs, just triggers the corresponding global input
+ * trigger. */
+static void input_led_set(struct led_classdev *cdev,
+ enum led_brightness brightness);
+static struct led_classdev input_leds[LED_CNT] = {
+#define DEFINE_INPUT_LED(input_led, nam, deftrig) \
+ [input_led] = { \
+ .name = "input::"nam, \
+ .max_brightness = 1, \
+ .brightness_set = input_led_set, \
+ .default_trigger = deftrig, \
+ }
+/* Default triggers for the global input LEDs just correspond to the legacy
+ * usage. */
+ DEFINE_INPUT_LED(LED_NUML, "numl", "numlock"),
+ DEFINE_INPUT_LED(LED_CAPSL, "capsl", "capslock"),
+ DEFINE_INPUT_LED(LED_SCROLLL, "scrolll", "scrollock"),
+ DEFINE_INPUT_LED(LED_COMPOSE, "compose", NULL),
+ DEFINE_INPUT_LED(LED_KANA, "kana", "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 input_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 input_led_trigger_activate(struct led_classdev *cdev);
+/* Global input triggers */
+static struct led_trigger input_led_triggers[LED_CNT] = {
+#define DEFINE_INPUT_LED_TRIGGER(input_led, nam) \
+ [input_led] = { \
+ .name = "input-"nam, \
+ .activate = input_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_SPINLOCK(input_led_registered_lock);
+/* Which global LED classes and triggers are registered */
+static unsigned long input_led_registered[BITS_TO_LONGS(LED_CNT)];
+
+/* Our input handler to catch connect/disconnect */
+static struct input_handler input_led_handler;
+
+/* Global input LED state change, tell the global input trigger. */
+static void input_led_set(struct led_classdev *cdev,
+ enum led_brightness brightness)
+{
+ int led = cdev - input_leds;
+
+ led_trigger_event(&input_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_handle *handle;
+ struct led_classdev *leds;
+ int led;
+
+ handle = cdev->dev->platform_data;
+ if (!handle)
+ /* Still initializing */
+ return;
+ leds = handle->private;
+ led = cdev - leds;
+
+ input_inject_event(handle, EV_LED, led, !!brightness);
+ input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
+}
+
+/* Keyboard hotplug, initialize its LED status */
+static void input_led_trigger_activate(struct led_classdev *cdev)
+{
+ struct led_trigger *trigger = cdev->trigger;
+ int led = trigger - input_led_triggers;
+
+ if (cdev->brightness_set)
+ cdev->brightness_set(cdev, input_leds[led].brightness);
+}
+
+/* Free an input handle, used at abortion and disconnection. */
+static void input_led_delete_handle(struct input_handle *handle)
+{
+ if (handle) {
+ struct led_classdev *leds = handle->private;
+ if (leds) {
+ int i;
+ for (i = 0; i < LED_CNT; i++)
+ kfree(leds[i].name);
+ kfree(leds);
+ }
+ kfree(handle);
+ }
+}
+
+/* A new input device with potential LEDs to connect. */
+static int input_led_connect(struct input_handler *handler,
+ struct input_dev *dev,
+ const struct input_device_id *id)
+{
+ struct input_handle *handle;
+ int i, error = 0;
+ unsigned long flags;
+ struct led_classdev *leds;
+
+ if (!test_bit(EV_LED, dev->keybit))
+ return -ENODEV;
+
+ handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+ if (!handle) {
+ error = -ENOMEM;
+ goto err;
+ }
+
+ handle->private = leds = kzalloc(sizeof(*leds) * LED_CNT,
+ GFP_KERNEL);
+ if (!handle->private) {
+ error = -ENOMEM;
+ goto err;
+ }
+
+ handle->dev = dev;
+ handle->handler = handler;
+ handle->name = "input leds";
+
+ error = input_register_handle(handle);
+ if (error)
+ goto err;
+
+ /* lazily register missing global input LEDs */
+ spin_lock_irqsave(&input_led_registered_lock, flags);
+ for (i = 0; i < LED_CNT; i++)
+ if (input_leds[i].name
+ && !test_bit(i, input_led_registered)
+ && test_bit(i, dev->ledbit)) {
+ led_trigger_register(&input_led_triggers[i]);
+ /* This keyboard has led i, try to register it */
+ if (!led_classdev_register(NULL, &input_leds[i]))
+ set_bit(i, input_led_registered);
+ else
+ led_trigger_unregister(&input_led_triggers[i]);
+ }
+ spin_unlock_irqrestore(&input_led_registered_lock, flags);
+
+ /* and register this device's LEDs */
+ for (i = 0; i < LED_CNT; i++)
+ if (input_leds[i].name && test_bit(i, dev->ledbit)) {
+ leds[i].name = kasprintf(GFP_KERNEL, "%s::%s",
+ dev_name(&dev->dev),
+ input_led_names[i]);
+ if (!leds[i].name) {
+ error = -ENOMEM;
+ goto err_handler;
+ }
+ leds[i].max_brightness = 1;
+ leds[i].brightness_set = perdevice_input_led_set;
+ leds[i].default_trigger = input_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 = handle;
+ perdevice_input_led_set(&leds[i],
+ input_leds[i].brightness);
+ }
+
+ return 0;
+
+err_handler:
+ input_unregister_handler(&input_led_handler);
+err:
+ input_led_delete_handle(handle);
+ return error;
+}
+
+/* Disconnected input device. Clean it, and deregister now-useless global LEDs
+ * and triggers. */
+static void input_led_disconnect(struct input_handle *handle)
+{
+ int unregister, i;
+ unsigned long flags;
+ struct led_classdev *leds = handle->private;
+
+ for (i = 0; i < LED_CNT; i++)
+ if (leds[i].name)
+ led_classdev_unregister(&leds[i]);
+
+ input_unregister_handle(handle);
+ input_led_delete_handle(handle);
+
+ spin_lock_irqsave(&input_led_registered_lock, flags);
+ for (i = 0; i < LED_CNT; i++) {
+ if (!test_bit(i, input_led_registered))
+ continue;
+
+ unregister = 1;
+ list_for_each_entry(handle, &input_led_handler.h_list, h_node) {
+ if (test_bit(i, handle->dev->ledbit)) {
+ unregister = 0;
+ break;
+ }
+ }
+ if (!unregister)
+ continue;
+
+ led_classdev_unregister(&input_leds[i]);
+ led_trigger_unregister(&input_led_triggers[i]);
+ clear_bit(i, input_led_registered);
+ }
+ spin_unlock_irqrestore(&input_led_registered_lock, flags);
+}
+
+/* Only handle input devices which have LEDs */
+static const struct input_device_id input_led_ids[] = {
+ {
+ .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+ .evbit = { BIT_MASK(EV_LED) },
+ },
+
+ { }, /* Terminating entry */
+};
+
+static struct input_handler input_led_handler = {
+ .connect = input_led_connect,
+ .disconnect = input_led_disconnect,
+ .name = "input leds",
+ .id_table = input_led_ids,
+};
+
+static int __init input_led_init(void)
+{
+ return input_register_handler(&input_led_handler);
+}
+
+static void __exit input_led_exit(void)
+{
+ /* This also disconnects all devices and thus unregisters LEDs and
+ * triggers */
+ input_unregister_handler(&input_led_handler);
+}
+
+module_init(input_led_init);
+module_exit(input_led_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("User LED support for input layer");
+MODULE_AUTHOR("Samuel Thibault <samuel.thibault(a)ens-lyon.org>");
diff -ur linux-2.6.33-orig/drivers/leds/Makefile linux-2.6.33-perso/drivers/leds/Makefile
--- linux-2.6.33-orig/drivers/leds/Makefile 2010-02-25 01:41:27.000000000 +0100
+++ linux-2.6.33-perso/drivers/leds/Makefile 2010-02-25 01:45:28.000000000 +0100
@@ -5,6 +5,7 @@
obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o

# LED Platform Drivers
+obj-$(CONFIG_LEDS_INPUT) += leds-input.o
obj-$(CONFIG_LEDS_ATMEL_PWM) += leds-atmel-pwm.o
obj-$(CONFIG_LEDS_BD2802) += leds-bd2802.o
obj-$(CONFIG_LEDS_LOCOMO) += leds-locomo.o
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Prev: [tip:perf/pebs] perf, x86: Fix pebs drains
Next: [PATCH]: cleanup debug message in irq_to_desc_alloc_node()