[PATCH 1/9] Input: add generic support for sparse keymaps

Dmitry Torokhov
2009-12-04T06:11:58Z

More and more devices choose to reimplement support for sparse keymaps
first introduced by wistron driver. Move it into a library module so it
can be easily used by interested parties.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---

Documentation/DocBook/device-drivers.tmpl | 4
drivers/input/Kconfig | 28 ++-
drivers/input/Makefile | 1
drivers/input/input-polldev.c | 14 +-
drivers/input/sparse-keymap.c | 251 +++++++++++++++++++++++++++++
include/linux/input/sparse-keymap.h | 62 +++++++
6 files changed, 348 insertions(+), 12 deletions(-)
create mode 100644 drivers/input/sparse-keymap.c
create mode 100644 include/linux/input/sparse-keymap.h

diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl
index e994d1d..f9a6e2c 100644
--- a/Documentation/DocBook/device-drivers.tmpl
+++ b/Documentation/DocBook/device-drivers.tmpl
@@ -306,6 +306,10 @@ X!Idrivers/video/console/fonts.c
<sect1> Matrix keyboars/keypads
!Iinclude/linux/input/matrix_keypad.h
</sect1>
+ <sect1> Sparse keymap support
+!Iinclude/linux/input/sparse-keymap.h
+!Edrivers/input/sparse-keymap.c
+ </sect1>
</chapter>

<chapter id="spi">
diff --git a/drivers/input/Kconfig b/drivers/input/Kconfig
index cd50c00..50af91e 100644
--- a/drivers/input/Kconfig
+++ b/drivers/input/Kconfig
@@ -8,7 +8,7 @@ menu "Input device support"
config INPUT
tristate "Generic input layer (needed for keyboard, mouse, ...)" if EMBEDDED
default y
- ---help---
+ help
Say Y here if you have any input device (mouse, keyboard, tablet,
joystick, steering wheel ...) connected to your system and want
it to be available to applications. This includes standard PS/2
@@ -27,8 +27,7 @@ if INPUT

config INPUT_FF_MEMLESS
tristate "Support for memoryless force-feedback devices"
- default n
- ---help---
+ help
Say Y here if you have memoryless force-feedback input device
such as Logitech WingMan Force 3D, ThrustMaster FireStorm Dual
Power 2, or similar. You will also need to enable hardware-specific
@@ -52,12 +51,25 @@ config INPUT_POLLDEV
To compile this driver as a module, choose M here: the
module will be called input-polldev.

+config INPUT_SPARSEKMAP
+ tristate "Sparse keymap support library"
+ help
+ Say Y here if you are using a driver for an input
+ device that uses sparse keymap. This option is only
+ useful for out-of-tree drivers since in-tree drivers
+ select it automatically.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called sparse-keymap.
+
comment "Userland interfaces"

config INPUT_MOUSEDEV
tristate "Mouse interface" if EMBEDDED
default y
- ---help---
+ help
Say Y here if you want your mouse to be accessible as char devices
13:32+ - /dev/input/mouseX and 13:63 - /dev/input/mice as an
emulated IntelliMouse Explorer PS/2 mouse. That way, all user space
@@ -73,7 +85,7 @@ config INPUT_MOUSEDEV_PSAUX
bool "Provide legacy /dev/psaux device"
default y
depends on INPUT_MOUSEDEV
- ---help---
+ help
Say Y here if you want your mouse also be accessible as char device
10:1 - /dev/psaux. The data available through /dev/psaux is exactly
the same as the data from /dev/input/mice.
@@ -103,7 +115,7 @@ config INPUT_MOUSEDEV_SCREEN_Y

config INPUT_JOYDEV
tristate "Joystick interface"
- ---help---
+ help
Say Y here if you want your joystick or gamepad to be
accessible as char device 13:0+ - /dev/input/jsX device.

@@ -125,7 +137,7 @@ config INPUT_EVDEV

config INPUT_EVBUG
tristate "Event debugging"
- ---help---
+ help
Say Y here if you have a problem with the input subsystem and
want all events (keypresses, mouse movements), to be output to
the system log. While this is useful for debugging, it's also
@@ -140,7 +152,7 @@ config INPUT_EVBUG
config INPUT_APMPOWER
tristate "Input Power Event -> APM Bridge" if EMBEDDED
depends on INPUT && APM_EMULATION
- ---help---
+ help
Say Y here if you want suspend key events to trigger a user
requested suspend through APM. This is useful on embedded
systems where such behaviour is desired without userspace
diff --git a/drivers/input/Makefile b/drivers/input/Makefile
index 4c9c745..7ad212d 100644
--- a/drivers/input/Makefile
+++ b/drivers/input/Makefile
@@ -9,6 +9,7 @@ input-core-objs := input.o input-compat.o ff-core.o

obj-$(CONFIG_INPUT_FF_MEMLESS) += ff-memless.o
obj-$(CONFIG_INPUT_POLLDEV) += input-polldev.o
+obj-$(CONFIG_INPUT_SPARSEKMAP) += sparse-keymap.o

obj-$(CONFIG_INPUT_MOUSEDEV) += mousedev.o
obj-$(CONFIG_INPUT_JOYDEV) += joydev.o
diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c
index 6a2eb39..aa6713b 100644
--- a/drivers/input/input-polldev.c
+++ b/drivers/input/input-polldev.c
@@ -212,7 +212,7 @@ EXPORT_SYMBOL(input_allocate_polled_device);
* @dev: device to free
*
* The function frees memory allocated for polling device and drops
- * reference to the associated input device (if present).
+ * reference to the associated input device.
*/
void input_free_polled_device(struct input_polled_dev *dev)
{
@@ -258,6 +258,15 @@ int input_register_polled_device(struct input_polled_dev *dev)
return error;
}

+ /*
+ * Take extra reference to the underlying input device so
+ * that it survives call to input_unregister_polled_device()
+ * and is deleted only after input_free_polled_device()
+ * has been invoked. This is needed to ease task of freeing
+ * sparse keymaps.
+ */
+ input_get_device(input);
+
return 0;
}
EXPORT_SYMBOL(input_register_polled_device);
@@ -269,8 +278,6 @@ EXPORT_SYMBOL(input_register_polled_device);
* The function unregisters previously registered polled input
* device from input layer. Polling is stopped and device is
* ready to be freed with call to input_free_polled_device().
- * Callers should not attempt to access dev->input pointer
- * after calling this function.
*/
void input_unregister_polled_device(struct input_polled_dev *dev)
{
@@ -278,7 +285,6 @@ void input_unregister_polled_device(struct input_polled_dev *dev)
&input_polldev_attribute_group);

input_unregister_device(dev->input);
- dev->input = NULL;
}
EXPORT_SYMBOL(input_unregister_polled_device);

diff --git a/drivers/input/sparse-keymap.c b/drivers/input/sparse-keymap.c
new file mode 100644
index 0000000..4655c56
--- /dev/null
+++ b/drivers/input/sparse-keymap.c
@@ -0,0 +1,251 @@
+/*
+ * Generic support for sparse keymaps
+ *
+ * Copyright (c) 2009 Dmitry Torokhov
+ *
+ * Derived from wistron button driver:
+ * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
+ * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
+ * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
+ *
+ * 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/input.h>
+#include <linux/input/sparse-keymap.h>
+
+MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
+MODULE_DESCRIPTION("Generic support for sparse keymaps");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("0.1");
+
+/**
+ * sparse_keymap_entry_from_scancode - perform sparse keymap lookup
+ * @dev: Input device using sparse keymap
+ * @code: Scan code
+ *
+ * This function is used to perform &struct key_entry lookup in an
+ * input device using sparse keymap.
+ */
+struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
+ unsigned int code)
+{
+ struct key_entry *key;
+
+ for (key = dev->keycode; key->type != KE_END; key++)
+ if (code == key->code)
+ return key;
+
+ return NULL;
+}
+EXPORT_SYMBOL(sparse_keymap_entry_from_scancode);
+
+/**
+ * sparse_keymap_entry_from_keycode - perform sparse keymap lookup
+ * @dev: Input device using sparse keymap
+ * @keycode: Key code
+ *
+ * This function is used to perform &struct key_entry lookup in an
+ * input device using sparse keymap.
+ */
+struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
+ unsigned int keycode)
+{
+ struct key_entry *key;
+
+ for (key = dev->keycode; key->type != KE_END; key++)
+ if (key->type == KE_KEY && keycode == key->keycode)
+ return key;
+
+ return NULL;
+}
+EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);
+
+static int sparse_keymap_getkeycode(struct input_dev *dev,
+ int scancode, int *keycode)
+{
+ const struct key_entry *key =
+ sparse_keymap_entry_from_scancode(dev, scancode);
+
+ if (key && key->type == KE_KEY) {
+ *keycode = key->keycode;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int sparse_keymap_setkeycode(struct input_dev *dev,
+ int scancode, int keycode)
+{
+ struct key_entry *key;
+ int old_keycode;
+
+ if (keycode < 0 || keycode > KEY_MAX)
+ return -EINVAL;
+
+ key = sparse_keymap_entry_from_scancode(dev, scancode);
+ if (key && key->type == KE_KEY) {
+ old_keycode = key->keycode;
+ key->keycode = keycode;
+ set_bit(keycode, dev->keybit);
+ if (!sparse_keymap_entry_from_keycode(dev, old_keycode))
+ clear_bit(old_keycode, dev->keybit);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(sparse_keymap_setkeycode);
+
+/**
+ * sparse_keymap_setup - set up sparse keymap for an input device
+ * @dev: Input device
+ * @keymap: Keymap in form of array of &key_entry structures ending
+ * with %KE_END type entry
+ * @setup: Function that can be used to adjust keymap entries
+ * depending on device's deeds, may be %NULL
+ *
+ * The function calculates size and allocates copy of the original
+ * keymap after which sets up input device event bits appropriately.
+ * Before detsroying input device allocated keymap should be freed
+ * with a call to sparse_keymap_free().
+ */
+int sparse_keymap_setup(struct input_dev *dev,
+ const struct key_entry *keymap,
+ int (*setup)(struct input_dev *, struct key_entry *))
+{
+ size_t map_size = 1; /* to account for the last KE_END entry */
+ const struct key_entry *e;
+ struct key_entry *map, *entry;
+ int i;
+ int error;
+
+ for (e = keymap; e->type != KE_END; e++)
+ map_size++;
+
+ map = kcalloc(map_size, sizeof (struct key_entry), GFP_KERNEL);
+ if (!map)
+ return -ENOMEM;
+
+ memcpy(map, keymap, map_size * sizeof (struct key_entry));
+
+ for (i = 0; i < map_size; i++) {
+ entry = &map[i];
+
+ if (setup) {
+ error = setup(dev, entry);
+ if (error)
+ goto err_out;
+ }
+
+ switch (entry->type) {
+ case KE_KEY:
+ __set_bit(EV_KEY, dev->evbit);
+ __set_bit(entry->keycode, dev->keybit);
+ break;
+
+ case KE_SW:
+ __set_bit(EV_SW, dev->evbit);
+ __set_bit(entry->sw.code, dev->swbit);
+ break;
+ }
+ }
+
+ dev->keycode = map;
+ dev->keycodemax = map_size;
+ dev->getkeycode = sparse_keymap_getkeycode;
+ dev->setkeycode = sparse_keymap_setkeycode;
+
+ return 0;
+
+ err_out:
+ kfree(keymap);
+ return error;
+
+}
+EXPORT_SYMBOL(sparse_keymap_setup);
+
+/**
+ * sparse_keymap_free - free memory allocated for sparse keymap
+ * @dev: Input device using sparse keymap
+ *
+ * This function is used to free memory allocated by sparse keymap
+ * in an input device that was set up by sparse_keymap_setup().
+ */
+void sparse_keymap_free(struct input_dev *dev)
+{
+ kfree(dev->keycode);
+ dev->keycode = NULL;
+ dev->keycodemax = 0;
+ dev->getkeycode = NULL;
+ dev->setkeycode = NULL;
+}
+EXPORT_SYMBOL(sparse_keymap_free);
+
+/**
+ * sparse_keymap_report_event - report event corresponding to given key entry
+ * @dev: Input device for which event should be reported
+ * @ke: key entry describing event
+ * @value: Value that should be reported (ignored by %KE_SW entries)
+ * @autorelease: Signals whether release event should be emitted for %KE_KEY
+ * entries right after reporting press event, ignored by all other
+ * entries
+ *
+ * This function is used to report input event described by given
+ * &struct key_entry.
+ */
+void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
+ unsigned int value, bool autorelease)
+{
+ switch (ke->type) {
+ case KE_KEY:
+ input_report_key(dev, ke->keycode, value);
+ input_sync(dev);
+ if (value && autorelease) {
+ input_report_key(dev, ke->keycode, 0);
+ input_sync(dev);
+ }
+ break;
+
+ case KE_SW:
+ value = ke->sw.value;
+ /* fall through */
+
+ case KE_VSW:
+ input_report_switch(dev, ke->sw.code, value);
+ break;
+ }
+}
+EXPORT_SYMBOL(sparse_keymap_report_entry);
+
+/**
+ * sparse_keymap_report_event - report event corresponding to given scancode
+ * @dev: Input device using sparse keymap
+ * @code: Scan code
+ * @value: Value that should be reported (ignored by %KE_SW entries)
+ * @autorelease: Signals whether release event should be emitted for %KE_KEY
+ * entries right after reporting press event, ignored by all other
+ * entries
+ *
+ * This function is used to perform lookup in an input device using sparse
+ * keymap and report corresponding event. Returns %true if lookup was
+ * successful and %false otherwise.
+ */
+bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
+ unsigned int value, bool autorelease)
+{
+ const struct key_entry *ke =
+ sparse_keymap_entry_from_scancode(dev, code);
+
+ if (ke) {
+ sparse_keymap_report_entry(dev, ke, value, autorelease);
+ return true;
+ }
+
+ return false;
+}
+EXPORT_SYMBOL(sparse_keymap_report_event);
+
diff --git a/include/linux/input/sparse-keymap.h b/include/linux/input/sparse-keymap.h
new file mode 100644
index 0000000..52db620
--- /dev/null
+++ b/include/linux/input/sparse-keymap.h
@@ -0,0 +1,62 @@
+#ifndef _SPARSE_KEYMAP_H
+#define _SPARSE_KEYMAP_H
+
+/*
+ * Copyright (c) 2009 Dmitry Torokhov
+ *
+ * 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.
+ */
+
+#define KE_END 0 /* Indicates end of keymap */
+#define KE_KEY 1 /* Ordinary key/button */
+#define KE_SW 2 /* Switch (predetermined value) */
+#define KE_VSW 3 /* Switch (value supplied at runtime) */
+#define KE_IGNORE 4 /* Known entry that should be ignored */
+#define KE_LAST KE_IGNORE
+
+/**
+ * struct key_entry - keymap entry for use in sparse keymap
+ * @type: Type of the key entry (KE_KEY, KE_SW, KE_VSW, KE_END);
+ * drivers are allowed to extend the list with their own
+ * private definitions.
+ * @code: Device-specific data identifying the button/switch
+ * @keycode: KEY_* code assigned to a key/button
+ * @sw.code: SW_* code assigned to a switch
+ * @sw.value: Value that should be sent in an input even when KE_SW
+ * switch is toggled. KE_VSW switches ignore this field and
+ * expect driver to supply value for the event.
+ *
+ * This structure defines an entry in a sparse keymap used by some
+ * input devices for which traditional table-based approach is not
+ * suitable.
+ */
+struct key_entry {
+ int type; /* See KE_* above */
+ u32 code;
+ union {
+ u16 keycode; /* For KE_KEY */
+ struct { /* For KE_SW, KE_VSW */
+ u8 code;
+ u8 value; /* For KE_SW, ignored by KE_VSW */
+ } sw;
+ };
+};
+
+struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
+ unsigned int code);
+struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
+ unsigned int code);
+int sparse_keymap_setup(struct input_dev *dev,
+ const struct key_entry *keymap,
+ int (*setup)(struct input_dev *, struct key_entry *));
+void sparse_keymap_free(struct input_dev *dev);
+
+void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
+ unsigned int value, bool autorelease);
+
+bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
+ unsigned int value, bool autorelease);
+
+#endif /* _SPARSE_KEYMAP_H */