[PATCH v2 4/4] platform/x86: thinkpad_acpi: Support hotkey to disable trackpoint doubletap

[Mark Pearson <mpearson-lenovo@squebb.ca>]

The hotkey combination FN+G can be used to disable the trackpoint
doubletap feature on Windows.
Add matching functionality for Linux.

Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
---
Changes in v2: 
 - Improved comments on keycodes in init function

 drivers/platform/x86/thinkpad_acpi.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index a2f21e958d39..370b9285156c 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -167,6 +167,7 @@ enum tpacpi_hkey_event_t {
 	TP_HKEY_EV_VOL_MUTE		= 0x1017, /* Mixer output mute */
 	TP_HKEY_EV_PRIVACYGUARD_TOGGLE	= 0x130f, /* Toggle priv.guard on/off */
 	TP_HKEY_EV_AMT_TOGGLE		= 0x131a, /* Toggle AMT on/off */
+	TP_HKEY_EV_DOUBLETAP_TOGGLE	= 0x131c, /* Toggle trackpoint doubletap on/off */
 	TP_HKEY_EV_PROFILE_TOGGLE	= 0x131f, /* Toggle platform profile */
 
 	/* Reasons for waking up from S3/S4 */
@@ -356,6 +357,7 @@ static struct {
 	u32 hotkey_poll_active:1;
 	u32 has_adaptive_kbd:1;
 	u32 kbd_lang:1;
+	u32 trackpoint_doubletap:1;
 	struct quirk_entry *quirks;
 } tp_features;
 
@@ -3346,7 +3348,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 		KEY_HANGUP_PHONE,		/* Decline incoming call */
 		KEY_UNKNOWN,			/* AMT_TOGGLE handled in driver, 0x31a */
 		KEY_UNKNOWN,			/* Camera Shutter Switch, 0X31b */
-		KEY_UNKNOWN,			/* DOUBLETAP_TOGGLE, 0x31c */
+		KEY_UNKNOWN,			/* DOUBLETAP_TOGGLE handled in driver, 0x31c */
 		KEY_VENDOR,                     /* System debug info, 0x31D */
 		KEY_PROG1,                      /* Trackpoint doubletap */
 		},
@@ -3606,6 +3608,9 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 
 	hotkey_poll_setup_safe(true);
 
+	/* Enable doubletap by default */
+	tp_features.trackpoint_doubletap = 1;
+
 	return 0;
 }
 
@@ -3747,6 +3752,7 @@ static bool hotkey_notify_extended_hotkey(const u32 hkey)
 	case TP_HKEY_EV_PRIVACYGUARD_TOGGLE:
 	case TP_HKEY_EV_AMT_TOGGLE:
 	case TP_HKEY_EV_PROFILE_TOGGLE:
+	case TP_HKEY_EV_DOUBLETAP_TOGGLE:
 		tpacpi_driver_event(hkey);
 		return true;
 	}
@@ -4011,7 +4017,7 @@ static bool hotkey_notify_6xxx(const u32 hkey,
 
 static bool hotkey_notify_8xxx(const u32 hkey)
 {
-	if (hkey == TP_HKEY_EV_TRACK_DOUBLETAP) {
+	if (hkey == TP_HKEY_EV_TRACK_DOUBLETAP && tp_features.trackpoint_doubletap) {
 		tpacpi_input_send_key(TP_ACPI_HOTKEYSCAN_DOUBLETAP);
 		return true;
 	}
@@ -11229,6 +11235,8 @@ static void tpacpi_driver_event(const unsigned int hkey_event)
 		/* Notify user space the profile changed */
 		platform_profile_notify();
 	}
+	if (hkey_event == TP_HKEY_EV_DOUBLETAP_TOGGLE)
+		tp_features.trackpoint_doubletap = !tp_features.trackpoint_doubletap;
 }
 
 static void hotkey_driver_event(const unsigned int scancode)
-- 
2.44.0