platform/x86: thinkpad_acpi: Use correct keycodes for volume and brightness keys

Change the default keymap to report the correct keycodes for the volume and
brightness keys. Reporting key events for these is already filtered out by
the hotkey_reserved_mask which masks these keys out of hotkey_user_mask at
initialization time, so there is no need to also map them to KEY_RESERVED.

This avoids users, who want these to be reported, having to also remap
the keycodes on top of overriding hotkey_user_mask to report these
and Linux userspace has already been overriding the KEY_RESERVED mappings
with the correct keycodes through udev/hwdb/60-keyboard.hwdb for years now.

Also drop hotkey_unmap() it was only used to dynamically map the brightness
keys to KEY_RESERVED and after removing that it has no remaining users.
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240424122834.19801-18-hdegoede@redhat.com

drivers/platform/x86/thinkpad_acpi.c

@@ -3097,15 +3097,6 @@ static void hotkey_exit(void)
 	mutex_unlock(&hotkey_mutex);
 }
 
-static void __init hotkey_unmap(const unsigned int scancode)
-{
-	if (hotkey_keycode_map[scancode] != KEY_RESERVED) {
-		clear_bit(hotkey_keycode_map[scancode],
-			  tpacpi_inputdev->keybit);
-		hotkey_keycode_map[scancode] = KEY_RESERVED;
-	}
-}
-
 /*
  * HKEY quirks:
  *   TPACPI_HK_Q_INIMASK:	Supports FN+F3,FN+F4,FN+F12
@@ -3224,22 +3215,28 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 		KEY_UNKNOWN,	/* 0x0D: FN+INSERT */
 		KEY_UNKNOWN,	/* 0x0E: FN+DELETE */
 
-		/* brightness: firmware always reacts to them */
-		KEY_RESERVED,	/* 0x0F: FN+HOME (brightness up) */
-		KEY_RESERVED,	/* 0x10: FN+END (brightness down) */
+		/* brightness: firmware always reacts to them.
+		 * Suppressed by default through hotkey_reserved_mask.
+		 */
+		KEY_BRIGHTNESSUP,	/* 0x0F: FN+HOME (brightness up) */
+		KEY_BRIGHTNESSDOWN,	/* 0x10: FN+END (brightness down) */
 
-		/* Thinklight: firmware always react to it */
-		KEY_RESERVED,	/* 0x11: FN+PGUP (thinklight toggle) */
+		/* Thinklight: firmware always react to it.
+		 * Suppressed by default through hotkey_reserved_mask.
+		 */
+		KEY_KBDILLUMTOGGLE,	/* 0x11: FN+PGUP (thinklight toggle) */
 
 		KEY_UNKNOWN,	/* 0x12: FN+PGDOWN */
 		KEY_ZOOM,	/* 0x13: FN+SPACE (zoom) */
 
 		/* Volume: firmware always react to it and reprograms
 		 * the built-in *extra* mixer.  Never map it to control
-		 * another mixer by default. */
-		KEY_RESERVED,	/* 0x14: VOLUME UP */
-		KEY_RESERVED,	/* 0x15: VOLUME DOWN */
-		KEY_RESERVED,	/* 0x16: MUTE */
+		 * another mixer by default.
+		 * Suppressed by default through hotkey_reserved_mask.
+		 */
+		KEY_VOLUMEUP,	/* 0x14: VOLUME UP */
+		KEY_VOLUMEDOWN,	/* 0x15: VOLUME DOWN */
+		KEY_MUTE,	/* 0x16: MUTE */
 
 		KEY_VENDOR,	/* 0x17: Thinkpad/AccessIBM/Lenovo */
 
@@ -3282,7 +3279,8 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 		KEY_BRIGHTNESSUP,	/* 0x0F: FN+HOME (brightness up) */
 		KEY_BRIGHTNESSDOWN,	/* 0x10: FN+END (brightness down) */
 
-		KEY_RESERVED,	/* 0x11: FN+PGUP (thinklight toggle) */
+		/* Suppressed by default through hotkey_reserved_mask. */
+		KEY_KBDILLUMTOGGLE,	/* 0x11: FN+PGUP (thinklight toggle) */
 
 		KEY_UNKNOWN,	/* 0x12: FN+PGDOWN */
 		KEY_ZOOM,	/* 0x13: FN+SPACE (zoom) */
@@ -3297,10 +3295,11 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 		 * change unless you get test reports from all Lenovo
 		 * models.  May cause the BIOS to interfere with the
 		 * HDA mixer.
+		 * Suppressed by default through hotkey_reserved_mask.
 		 */
-		KEY_RESERVED,	/* 0x14: VOLUME UP */
-		KEY_RESERVED,	/* 0x15: VOLUME DOWN */
-		KEY_RESERVED,	/* 0x16: MUTE */
+		KEY_VOLUMEUP,	/* 0x14: VOLUME UP */
+		KEY_VOLUMEDOWN,	/* 0x15: VOLUME DOWN */
+		KEY_MUTE,	/* 0x16: MUTE */
 
 		KEY_VENDOR,	/* 0x17: Thinkpad/AccessIBM/Lenovo */
 
@@ -3599,8 +3598,6 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 		 * for userspace to do something even remotely sane */
 		hotkey_reserved_mask |= TP_ACPI_HKEY_BRGHTUP_MASK |
 					TP_ACPI_HKEY_BRGHTDWN_MASK;
-		hotkey_unmap(TP_ACPI_HOTKEYSCAN_FNHOME);
-		hotkey_unmap(TP_ACPI_HOTKEYSCAN_FNEND);
 	}
 
 #ifdef CONFIG_THINKPAD_ACPI_HOTKEY_POLL