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

1 files changed, 62 insertions, 0 deletions

diff --git a/include/linux/input/sparse-keymap.h b/include/linux/input/sparse-keymap.h
new file mode 100644
index 000000000000..52db62064c6e
--- /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 */