Input: document some of keycodes

Document some of keycodes, based on USB HUT 1.12 and current mapping
in HID driver.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

include/linux/input.h

@@ -108,6 +108,13 @@ struct input_absinfo {
 
 /*
  * Keys and buttons
+ *
+ * Most of the keys/buttons are modeled after USB HUT 1.12
+ * (see http://www.usb.org/developers/hidpage).
+ * Abbreviations in the comments:
+ * AC - Application Control
+ * AL - Application Launch Button
+ * SC - System Control
  */
 
 #define KEY_RESERVED		0
@@ -226,7 +233,7 @@ struct input_absinfo {
 #define KEY_MUTE		113
 #define KEY_VOLUMEDOWN		114
 #define KEY_VOLUMEUP		115
-#define KEY_POWER		116
+#define KEY_POWER		116	/* SC System Power Down */
 #define KEY_KPEQUAL		117
 #define KEY_KPPLUSMINUS		118
 #define KEY_PAUSE		119
@@ -240,38 +247,39 @@ struct input_absinfo {
 #define KEY_RIGHTMETA		126
 #define KEY_COMPOSE		127
 
-#define KEY_STOP		128
+#define KEY_STOP		128	/* AC Stop */
 #define KEY_AGAIN		129
-#define KEY_PROPS		130
-#define KEY_UNDO		131
+#define KEY_PROPS		130	/* AC Properties */
+#define KEY_UNDO		131	/* AC Undo */
 #define KEY_FRONT		132
-#define KEY_COPY		133
-#define KEY_OPEN		134
-#define KEY_PASTE		135
-#define KEY_FIND		136
-#define KEY_CUT			137
-#define KEY_HELP		138
-#define KEY_MENU		139
-#define KEY_CALC		140
+#define KEY_COPY		133	/* AC Copy */
+#define KEY_OPEN		134	/* AC Open */
+#define KEY_PASTE		135	/* AC Paste */
+#define KEY_FIND		136	/* AC Search */
+#define KEY_CUT			137	/* AC Cut */
+#define KEY_HELP		138	/* AL Integrated Help Center */
+#define KEY_MENU		139	/* Menu (show menu) */
+#define KEY_CALC		140	/* AL Calculator */
 #define KEY_SETUP		141
-#define KEY_SLEEP		142
-#define KEY_WAKEUP		143
-#define KEY_FILE		144
+#define KEY_SLEEP		142	/* SC System Sleep */
+#define KEY_WAKEUP		143	/* System Wake Up */
+#define KEY_FILE		144	/* AL Local Machine Browser */
 #define KEY_SENDFILE		145
 #define KEY_DELETEFILE		146
 #define KEY_XFER		147
 #define KEY_PROG1		148
 #define KEY_PROG2		149
-#define KEY_WWW			150
+#define KEY_WWW			150	/* AL Internet Browser */
 #define KEY_MSDOS		151
-#define KEY_COFFEE		152
+#define KEY_COFFEE		152	/* AL Terminal Lock/Screensaver */
+#define KEY_SCREENLOCK		KEY_COFFEE
 #define KEY_DIRECTION		153
 #define KEY_CYCLEWINDOWS	154
 #define KEY_MAIL		155
-#define KEY_BOOKMARKS		156
+#define KEY_BOOKMARKS		156	/* AC Bookmarks */
 #define KEY_COMPUTER		157
-#define KEY_BACK		158
-#define KEY_FORWARD		159
+#define KEY_BACK		158	/* AC Back */
+#define KEY_FORWARD		159	/* AC Forward */
 #define KEY_CLOSECD		160
 #define KEY_EJECTCD		161
 #define KEY_EJECTCLOSECD	162
@@ -281,20 +289,20 @@ struct input_absinfo {
 #define KEY_STOPCD		166
 #define KEY_RECORD		167
 #define KEY_REWIND		168
-#define KEY_PHONE		169
+#define KEY_PHONE		169	/* Media Select Telephone */
 #define KEY_ISO			170
-#define KEY_CONFIG		171
-#define KEY_HOMEPAGE		172
-#define KEY_REFRESH		173
-#define KEY_EXIT		174
+#define KEY_CONFIG		171	/* AL Consumer Control Configuration */
+#define KEY_HOMEPAGE		172	/* AC Home */
+#define KEY_REFRESH		173	/* AC Refresh */
+#define KEY_EXIT		174	/* AC Exit */
 #define KEY_MOVE		175
 #define KEY_EDIT		176
 #define KEY_SCROLLUP		177
 #define KEY_SCROLLDOWN		178
 #define KEY_KPLEFTPAREN		179
 #define KEY_KPRIGHTPAREN	180
-#define KEY_NEW			181
-#define KEY_REDO		182
+#define KEY_NEW			181	/* AC New */
+#define KEY_REDO		182	/* AC Redo/Repeat */
 
 #define KEY_F13			183
 #define KEY_F14			184
@@ -314,11 +322,11 @@ struct input_absinfo {
 #define KEY_PROG3		202
 #define KEY_PROG4		203
 #define KEY_SUSPEND		205
-#define KEY_CLOSE		206
+#define KEY_CLOSE		206	/* AC Close */
 #define KEY_PLAY		207
 #define KEY_FASTFORWARD		208
 #define KEY_BASSBOOST		209
-#define KEY_PRINT		210
+#define KEY_PRINT		210	/* AC Print */
 #define KEY_HP			211
 #define KEY_CAMERA		212
 #define KEY_SOUND		213
@@ -327,11 +335,11 @@ struct input_absinfo {
 #define KEY_CHAT		216
 #define KEY_SEARCH		217
 #define KEY_CONNECT		218
-#define KEY_FINANCE		219
+#define KEY_FINANCE		219	/* AL Checkbook/Finance */
 #define KEY_SPORT		220
 #define KEY_SHOP		221
 #define KEY_ALTERASE		222
-#define KEY_CANCEL		223
+#define KEY_CANCEL		223	/* AC Cancel */
 #define KEY_BRIGHTNESSDOWN	224
 #define KEY_BRIGHTNESSUP	225
 #define KEY_MEDIA		226
@@ -341,10 +349,10 @@ struct input_absinfo {
 #define KEY_KBDILLUMDOWN	229
 #define KEY_KBDILLUMUP		230
 
-#define KEY_SEND		231
-#define KEY_REPLY		232
-#define KEY_FORWARDMAIL		233
-#define KEY_SAVE		234
+#define KEY_SEND		231	/* AC Send */
+#define KEY_REPLY		232	/* AC Reply */
+#define KEY_FORWARDMAIL		233	/* AC Forward Msg */
+#define KEY_SAVE		234	/* AC Save */
 #define KEY_DOCUMENTS		235
 
 #define KEY_BATTERY		236
@@ -433,15 +441,15 @@ struct input_absinfo {
 #define KEY_CLEAR		0x163
 #define KEY_POWER2		0x164
 #define KEY_OPTION		0x165
-#define KEY_INFO		0x166
+#define KEY_INFO		0x166	/* AL OEM Features/Tips/Tutorial */
 #define KEY_TIME		0x167
 #define KEY_VENDOR		0x168
 #define KEY_ARCHIVE		0x169
-#define KEY_PROGRAM		0x16a
+#define KEY_PROGRAM		0x16a	/* Media Select Program Guide */
 #define KEY_CHANNEL		0x16b
 #define KEY_FAVORITES		0x16c
 #define KEY_EPG			0x16d
-#define KEY_PVR			0x16e
+#define KEY_PVR			0x16e	/* Media Select Home */
 #define KEY_MHP			0x16f
 #define KEY_LANGUAGE		0x170
 #define KEY_TITLE		0x171
@@ -451,36 +459,36 @@ struct input_absinfo {
 #define KEY_MODE		0x175
 #define KEY_KEYBOARD		0x176
 #define KEY_SCREEN		0x177
-#define KEY_PC			0x178
-#define KEY_TV			0x179
-#define KEY_TV2			0x17a
-#define KEY_VCR			0x17b
-#define KEY_VCR2		0x17c
-#define KEY_SAT			0x17d
+#define KEY_PC			0x178	/* Media Select Computer */
+#define KEY_TV			0x179	/* Media Select TV */
+#define KEY_TV2			0x17a	/* Media Select Cable */
+#define KEY_VCR			0x17b	/* Media Select VCR */
+#define KEY_VCR2		0x17c	/* VCR Plus */
+#define KEY_SAT			0x17d	/* Media Select Satellite */
 #define KEY_SAT2		0x17e
-#define KEY_CD			0x17f
-#define KEY_TAPE		0x180
+#define KEY_CD			0x17f	/* Media Select CD */
+#define KEY_TAPE		0x180	/* Media Select Tape */
 #define KEY_RADIO		0x181
-#define KEY_TUNER		0x182
+#define KEY_TUNER		0x182	/* Media Select Tuner */
 #define KEY_PLAYER		0x183
 #define KEY_TEXT		0x184
-#define KEY_DVD			0x185
+#define KEY_DVD			0x185	/* Media Select DVD */
 #define KEY_AUX			0x186
 #define KEY_MP3			0x187
 #define KEY_AUDIO		0x188
 #define KEY_VIDEO		0x189
 #define KEY_DIRECTORY		0x18a
 #define KEY_LIST		0x18b
-#define KEY_MEMO		0x18c
+#define KEY_MEMO		0x18c	/* Media Select Messages */
 #define KEY_CALENDAR		0x18d
 #define KEY_RED			0x18e
 #define KEY_GREEN		0x18f
 #define KEY_YELLOW		0x190
 #define KEY_BLUE		0x191
-#define KEY_CHANNELUP		0x192
-#define KEY_CHANNELDOWN		0x193
+#define KEY_CHANNELUP		0x192	/* Channel Increment */
+#define KEY_CHANNELDOWN		0x193	/* Channel Decrement */
 #define KEY_FIRST		0x194
-#define KEY_LAST		0x195
+#define KEY_LAST		0x195	/* Recall Last */
 #define KEY_AB			0x196
 #define KEY_NEXT		0x197
 #define KEY_RESTART		0x198
@@ -491,21 +499,21 @@ struct input_absinfo {
 #define KEY_DIGITS		0x19d
 #define KEY_TEEN		0x19e
 #define KEY_TWEN		0x19f
-#define KEY_VIDEOPHONE		0x1a0
-#define KEY_GAMES		0x1a1
-#define KEY_ZOOMIN		0x1a2
-#define KEY_ZOOMOUT		0x1a3
-#define KEY_ZOOMRESET		0x1a4
-#define KEY_WORDPROCESSOR	0x1a5
-#define KEY_EDITOR		0x1a6
-#define KEY_SPREADSHEET		0x1a7
-#define KEY_GRAPHICSEDITOR	0x1a8
-#define KEY_PRESENTATION	0x1a9
-#define KEY_DATABASE		0x1aa
-#define KEY_NEWS		0x1ab
-#define KEY_VOICEMAIL		0x1ac
-#define KEY_ADDRESSBOOK		0x1ad
-#define KEY_MESSENGER		0x1ae
+#define KEY_VIDEOPHONE		0x1a0	/* Media Select Video Phone */
+#define KEY_GAMES		0x1a1	/* Media Select Games */
+#define KEY_ZOOMIN		0x1a2	/* AC Zoom In */
+#define KEY_ZOOMOUT		0x1a3	/* AC Zoom Out */
+#define KEY_ZOOMRESET		0x1a4	/* AC Zoom */
+#define KEY_WORDPROCESSOR	0x1a5	/* AL Word Processor */
+#define KEY_EDITOR		0x1a6	/* AL Text Editor */
+#define KEY_SPREADSHEET		0x1a7	/* AL Spreadsheet */
+#define KEY_GRAPHICSEDITOR	0x1a8	/* AL Graphics Editor */
+#define KEY_PRESENTATION	0x1a9	/* AL Presentation App */
+#define KEY_DATABASE		0x1aa	/* AL Database App */
+#define KEY_NEWS		0x1ab	/* AL Newsreader */
+#define KEY_VOICEMAIL		0x1ac	/* AL Voicemail */
+#define KEY_ADDRESSBOOK		0x1ad	/* AL Contacts/Address Book */
+#define KEY_MESSENGER		0x1ae	/* AL Instant Messaging */
 #define KEY_DISPLAYTOGGLE	0x1af	/* Turn display (LCD) on and off */
 
 #define KEY_DEL_EOL		0x1c0