Input: Add event-codes for macro keys found on various keyboards

Various keyboards have macro keys, which are intended to have user
programmable actions / key-sequences bound to them. In some cases these
macro keys are actually programmable in hardware, but more often they
basically are just extra keys and the playback of the key-sequence is done
by software running on the host.

One example of keyboards with macro-keys are various "internet" / "office"
keyboards have a set of so-called "Smart Keys", typically a set of 4 keys
labeled "[A]" - "[D]".

Another example are gaming keyboards, such as the Logitech G15 Gaming
keyboard, which has 18 "G"aming keys labeled "G1" to G18", 3 keys to select
macro presets labeled "M1" - "M3" and a key to start recording a macro
called "MR" note that even though there us a record key everything is
handled in sw on the host.

Besides macro keys the G15 (and other gaming keyboards) also has a buildin
LCD panel where the contents are controlled by the host. There are 5 keys
directly below the LCD intended for controlling a menu shown on the LCD.

The Microsoft SideWinder X6 keyboard is another gaming keyboard example,
this keyboard has 30 "S"idewinder keys and a key to cycle through
macro-presets.

After discussion between various involved userspace people we've come to
the conclusion that since these are all really just extra keys we should
simply treat them as such and give them their own event-codes, see:
https://github.com/libratbag/libratbag/issues/172

This commit adds the following new KEY_ defines for this:

KEY_MACRO1 - KEY_MACRO30. KEY_MACRO_RECORD_START/-STOP,
KEY_MACRO_PRESET_CYCLE, KEY_MACRO_PRESET1 - KEY_MACRO_PRESET3,
KEY_KBD_LCD_MENU1 - KEY_KBD_LCD_MENU5.

The defines leave room for adding some more LCD-menu, preset or macro keys,
the maximum values above are based on the maximum values to support all
currently known internet, office and gaming keyboards.

BugLink: https://github.com/libratbag/libratbag/issues/172Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

include/uapi/linux/input-event-codes.h

@@ -650,6 +650,81 @@
 #define KEY_DATA			0x277
 #define KEY_ONSCREEN_KEYBOARD		0x278
 
+/*
+ * Some keyboards have keys which do not have a defined meaning, these keys
+ * are intended to be programmed / bound to macros by the user. For most
+ * keyboards with these macro-keys the key-sequence to inject, or action to
+ * take, is all handled by software on the host side. So from the kernel's
+ * point of view these are just normal keys.
+ *
+ * The KEY_MACRO# codes below are intended for such keys, which may be labeled
+ * e.g. G1-G18, or S1 - S30. The KEY_MACRO# codes MUST NOT be used for keys
+ * where the marking on the key does indicate a defined meaning / purpose.
+ *
+ * The KEY_MACRO# codes MUST also NOT be used as fallback for when no existing
+ * KEY_FOO define matches the marking / purpose. In this case a new KEY_FOO
+ * define MUST be added.
+ */
+#define KEY_MACRO1			0x290
+#define KEY_MACRO2			0x291
+#define KEY_MACRO3			0x292
+#define KEY_MACRO4			0x293
+#define KEY_MACRO5			0x294
+#define KEY_MACRO6			0x295
+#define KEY_MACRO7			0x296
+#define KEY_MACRO8			0x297
+#define KEY_MACRO9			0x298
+#define KEY_MACRO10			0x299
+#define KEY_MACRO11			0x29a
+#define KEY_MACRO12			0x29b
+#define KEY_MACRO13			0x29c
+#define KEY_MACRO14			0x29d
+#define KEY_MACRO15			0x29e
+#define KEY_MACRO16			0x29f
+#define KEY_MACRO17			0x2a0
+#define KEY_MACRO18			0x2a1
+#define KEY_MACRO19			0x2a2
+#define KEY_MACRO20			0x2a3
+#define KEY_MACRO21			0x2a4
+#define KEY_MACRO22			0x2a5
+#define KEY_MACRO23			0x2a6
+#define KEY_MACRO24			0x2a7
+#define KEY_MACRO25			0x2a8
+#define KEY_MACRO26			0x2a9
+#define KEY_MACRO27			0x2aa
+#define KEY_MACRO28			0x2ab
+#define KEY_MACRO29			0x2ac
+#define KEY_MACRO30			0x2ad
+
+/*
+ * Some keyboards with the macro-keys described above have some extra keys
+ * for controlling the host-side software responsible for the macro handling:
+ * -A macro recording start/stop key. Note that not all keyboards which emit
+ *  KEY_MACRO_RECORD_START will also emit KEY_MACRO_RECORD_STOP if
+ *  KEY_MACRO_RECORD_STOP is not advertised, then KEY_MACRO_RECORD_START
+ *  should be interpreted as a recording start/stop toggle;
+ * -Keys for switching between different macro (pre)sets, either a key for
+ *  cycling through the configured presets or keys to directly select a preset.
+ */
+#define KEY_MACRO_RECORD_START		0x2b0
+#define KEY_MACRO_RECORD_STOP		0x2b1
+#define KEY_MACRO_PRESET_CYCLE		0x2b2
+#define KEY_MACRO_PRESET1		0x2b3
+#define KEY_MACRO_PRESET2		0x2b4
+#define KEY_MACRO_PRESET3		0x2b5
+
+/*
+ * Some keyboards have a buildin LCD panel where the contents are controlled
+ * by the host. Often these have a number of keys directly below the LCD
+ * intended for controlling a menu shown on the LCD. These keys often don't
+ * have any labeling so we just name them KEY_KBD_LCD_MENU#
+ */
+#define KEY_KBD_LCD_MENU1		0x2b8
+#define KEY_KBD_LCD_MENU2		0x2b9
+#define KEY_KBD_LCD_MENU3		0x2ba
+#define KEY_KBD_LCD_MENU4		0x2bb
+#define KEY_KBD_LCD_MENU5		0x2bc
+
 #define BTN_TRIGGER_HAPPY		0x2c0
 #define BTN_TRIGGER_HAPPY1		0x2c0
 #define BTN_TRIGGER_HAPPY2		0x2c1