[PATCH v3] hid-playstation: DS4: Update rumble and lightbar together

[Max Staudt <max@enpas.org>]

Some 3rd party gamepads expect updates to rumble and lightbar together,
and setting one may cancel the other.

Let's maximise compatibility by always sending rumble and lightbar
updates together, even when only one has been scheduled.

Further background reading:

- Apparently the PS4 always sends rumble and lightbar updates together:

  https://eleccelerator.com/wiki/index.php?title=DualShock_4#0x11_2

- 3rd party gamepads may not implement lightbar_blink, and may simply
  ignore updates with 0x07 set, according to:

  https://github.com/Ryochan7/DS4Windows/pull/1839

Signed-off-by: Max Staudt <max@enpas.org>
---
Changes in v2 -> v3:
 - Introduced a quirk bit, so this hack only applies to controllers known
   to be quirky.
---
 drivers/hid/hid-playstation.c | 50 +++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
index e7c309cfe3a0..79482c56fc40 100644
--- a/drivers/hid/hid-playstation.c
+++ b/drivers/hid/hid-playstation.c
@@ -356,6 +356,9 @@ struct dualsense_output_report {
 #define DS4_TOUCHPAD_WIDTH	1920
 #define DS4_TOUCHPAD_HEIGHT	942
 
+/* Quirks for third-party controllers */
+#define DS4_QUIRK_OUTPUT_LIGHTBAR_RUMBLE_TOGETHER	BIT(0)
+
 enum dualshock4_dongle_state {
 	DONGLE_DISCONNECTED,
 	DONGLE_CALIBRATING,
@@ -405,6 +408,8 @@ struct dualshock4 {
 	struct work_struct output_worker;
 	bool output_worker_initialized;
 	void *output_report_dmabuf;
+
+	unsigned long quirks;
 };
 
 struct dualshock4_touch_point {
@@ -2143,6 +2148,28 @@ static void dualshock4_output_worker(struct work_struct *work)
 
 	spin_lock_irqsave(&ds4->base.lock, flags);
 
+	/*
+	 * Some 3rd party gamepads expect updates to rumble and lightbar
+	 * together, and setting one may cancel the other.
+	 *
+	 * Let's maximise compatibility by always sending rumble and lightbar
+	 * updates together, even when only one has been scheduled, resulting
+	 * in:
+	 *
+	 *   ds4->valid_flag0 >= 0x03
+	 *
+	 * Hopefully this will maximise compatibility with third-party pads.
+	 *
+	 * Any further update bits, such as 0x04 for lightbar blinking, will
+	 * be or'd on top of this like before.
+	 */
+	if (DS4_QUIRK_OUTPUT_LIGHTBAR_RUMBLE_TOGETHER) {
+		if (ds4->update_rumble || ds4->update_lightbar) {
+			ds4->update_rumble = true; /* 0x01 */
+			ds4->update_lightbar = true; /* 0x02 */
+		}
+	}
+
 	if (ds4->update_rumble) {
 		/* Select classic rumble style haptics and enable it. */
 		common->valid_flag0 |= DS4_OUTPUT_VALID_FLAG0_MOTOR;
@@ -2558,6 +2585,29 @@ static struct ps_device *dualshock4_create(struct hid_device *hdev)
 	 */
 	hdev->version |= HID_PLAYSTATION_VERSION_PATCH;
 
+	/*
+	 * Some 3rd party gamepads expect updates to rumble and lightbar
+	 * together, and setting one may cancel the other.
+	 *
+	 * Set a quirk bit if this is a controller known to behave this way.
+	 */
+	if (hdev->vendor == USB_VENDOR_ID_SONY &&
+	    hdev->product == USB_DEVICE_ID_SONY_PS4_CONTROLLER_2) {
+		/*
+		 * Match quirky controllers by their HID report descriptor.
+		 * Check for >= instead of == because there may be a trailing
+		 * 0x00 or the like.
+		 */
+		if (hdev->bus == BUS_USB && hdev->rsize >= 507 &&
+		    crc32_le(0xffffffff, hdev->rdesc, 507) == 0xabc63a20)
+			ds4->quirks |= DS4_QUIRK_OUTPUT_LIGHTBAR_RUMBLE_TOGETHER;
+
+		/* The descriptor via Bluetooth differs from the USB one. */
+		if (hdev->bus == BUS_BLUETOOTH && hdev->rsize >= 430 &&
+		    crc32_le(0xffffffff, hdev->rdesc, 430) == 0x4194b762)
+			ds4->quirks |= DS4_QUIRK_OUTPUT_LIGHTBAR_RUMBLE_TOGETHER;
+	}
+
 	ps_dev = &ds4->base;
 	ps_dev->hdev = hdev;
 	spin_lock_init(&ps_dev->lock);
-- 
2.39.2