[PATCH v2 6/6] HID: steam: Zero out inputs when disabling gamepad mode

[Vicki Pfau <vi@endrift.com>]

When gamepad mode is disabled the gamepad input devices will stop receiving
updates. However, in the case where there are buttons still pressed this
will appear as an indefinitely-held button. Instead we should zero out the
inputs to make it look like things are all released. We do the same thing
for gyroscope inputs to make sure it doesn't look like it's endlessly
rotating, but we freeze the accelerometer input since zero isn't a neutral
input on the surface of the Earth.

Signed-off-by: Vicki Pfau <vi@endrift.com>
---
 drivers/hid/hid-steam.c | 69 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 67 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
index 01801f2a5886..0c159ae7bf1a 100644
--- a/drivers/hid/hid-steam.c
+++ b/drivers/hid/hid-steam.c
@@ -1498,11 +1498,76 @@ static void steam_mode_switch_cb(struct work_struct *work)
 
 	guard(mutex)(&steam->report_mutex);
 	hid_dbg(steam->hdev, "%s: switching gamepad mode to %i\n", __func__, steam->gamepad_mode);
-	if (gamepad_mode)
+	if (gamepad_mode) {
 		steam_set_lizard_mode(steam, false);
-	else {
+	} else {
+		struct input_dev *input;
+		struct input_dev *sensors;
+
 		if (!client_opened)
 			steam_set_lizard_mode(steam, lizard_mode);
+
+		/*
+		 * Zero out inputs so it doesn't look like we're holding
+		 * anything indefinitely.
+		 */
+		guard(spinlock_irqsave)(&steam->lock);
+		rcu_read_lock();
+		input = rcu_dereference(steam->input);
+		if (likely(input)) {
+			input_report_key(input, BTN_TR2, 0);
+			input_report_key(input, BTN_TL2, 0);
+			input_report_key(input, BTN_TR, 0);
+			input_report_key(input, BTN_TL, 0);
+			input_report_key(input, BTN_Y, 0);
+			input_report_key(input, BTN_B, 0);
+			input_report_key(input, BTN_X, 0);
+			input_report_key(input, BTN_A, 0);
+			input_report_key(input, BTN_DPAD_UP, 0);
+			input_report_key(input, BTN_DPAD_RIGHT, 0);
+			input_report_key(input, BTN_DPAD_LEFT, 0);
+			input_report_key(input, BTN_DPAD_DOWN, 0);
+			input_report_key(input, BTN_SELECT, 0);
+			input_report_key(input, BTN_MODE, 0);
+			input_report_key(input, BTN_START, 0);
+			input_report_key(input, BTN_THUMBR, 0);
+			input_report_key(input, BTN_THUMBL, 0);
+			input_report_key(input, BTN_THUMB, 0);
+			input_report_key(input, BTN_THUMB2, 0);
+			input_report_key(input, BTN_GRIPL, 0);
+			input_report_key(input, BTN_GRIPR, 0);
+
+			input_report_abs(input, ABS_X, 0);
+			input_report_abs(input, ABS_Y, 0);
+			input_report_abs(input, ABS_RX, 0);
+			input_report_abs(input, ABS_RY, 0);
+			input_report_abs(input, ABS_HAT0X, 0);
+			input_report_abs(input, ABS_HAT0Y, 0);
+			input_report_abs(input, ABS_HAT2Y, 0);
+			input_report_abs(input, ABS_HAT2X, 0);
+
+			if (steam->quirks & (STEAM_QUIRK_DECK | STEAM_QUIRK_IBEX)) {
+				input_report_key(input, BTN_BASE, 0);
+				input_report_key(input, BTN_GRIPL2, 0);
+				input_report_key(input, BTN_GRIPR2, 0);
+
+				input_report_abs(input, ABS_HAT1X, 0);
+				input_report_abs(input, ABS_HAT1Y, 0);
+			}
+
+			input_sync(input);
+		}
+		sensors = rcu_dereference(steam->sensors);
+		if (likely(sensors)) {
+			/* Skip accelerometers since 0 isn't a neutral input */
+
+			input_report_abs(sensors, ABS_RX, 0);
+			input_report_abs(sensors, ABS_RY, 0);
+			input_report_abs(sensors, ABS_RZ, 0);
+
+			input_sync(sensors);
+		}
+		rcu_read_unlock();
 	}
 
 	steam_haptic_pulse(steam, STEAM_PAD_RIGHT, 0x190, 0, 1, 0);
-- 
2.54.0