Input: add generic support for sparse keymaps
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.
Reviewed-by: Anisse Astier <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
diff --git a/drivers/input/sparse-keymap.c b/drivers/input/sparse-keymap.c
new file mode 100644
index 0000000..fbd3987
--- /dev/null
+++ b/drivers/input/sparse-keymap.c
@@ -0,0 +1,250 @@
+/*
+ * Generic support for sparse keymaps
+ *
+ * Copyright (c) 2009 Dmitry Torokhov
+ *
+ * Derived from wistron button driver:
+ * Copyright (C) 2005 Miloslav Trmac <[email protected]>
+ * Copyright (C) 2005 Bernhard Rosenkraenzer <[email protected]>
+ * Copyright (C) 2005 Dmitry Torokhov <[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/input.h>
+#include <linux/input/sparse-keymap.h>
+
+MODULE_AUTHOR("Dmitry Torokhov <[email protected]>");
+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;
+}
+
+/**
+ * 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 destroying 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_entry - 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);
+
