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Date:   Thu, 20 Sep 2018 16:13:08 -0700
Message-Id: <20180920231308.237277-1-seobrien@chromium.org>
Mime-Version: 1.0
Subject: [PATCH] [v3] HID: add support for Apple Magic Trackpad 2
From:   "Sean O'Brien" <seobrien@chromium.org>
To:     Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc:     "Sean O'Brien" <seobrien@chromium.org>,
        Marek Wyborski <marek.wyborski@emwesoft.com>,
        linux-kernel@vger.kernel.org,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        linux-input@vger.kernel.org, Henrik Rydberg <rydberg@bitmath.org>,
        Jiri Kosina <jikos@kernel.org>,
        Claudio Mettler <claudio@ponyfleisch.ch>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

USB device
        Vendor 05ac (Apple)
        Device 0265 (Magic Trackpad 2)
Bluetooth device
        Vendor 004c (Apple)
        Device 0265 (Magic Trackpad 2)

Add support for Apple Magic Trackpad 2 over USB and bluetooth, putting
the device in multi-touch mode.

Signed-off-by: Claudio Mettler <claudio@ponyfleisch.ch>
Signed-off-by: Marek Wyborski <marek.wyborski@emwesoft.com>
Signed-off-by: Sean O'Brien <seobrien@chromium.org>
---

 drivers/hid/hid-ids.h        |   1 +
 drivers/hid/hid-magicmouse.c | 149 +++++++++++++++++++++++++++++++----
 2 files changed, 134 insertions(+), 16 deletions(-)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 5146ee029db4..bb0cd212c7cc 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -92,6 +92,7 @@
 #define USB_DEVICE_ID_APPLE_MIGHTYMOUSE	0x0304
 #define USB_DEVICE_ID_APPLE_MAGICMOUSE	0x030d
 #define USB_DEVICE_ID_APPLE_MAGICTRACKPAD	0x030e
+#define USB_DEVICE_ID_APPLE_MAGICTRACKPAD2	0x0265
 #define USB_DEVICE_ID_APPLE_FOUNTAIN_ANSI	0x020e
 #define USB_DEVICE_ID_APPLE_FOUNTAIN_ISO	0x020f
 #define USB_DEVICE_ID_APPLE_GEYSER_ANSI	0x0214
diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
index b454c4386157..6a3a6c83e509 100644
--- a/drivers/hid/hid-magicmouse.c
+++ b/drivers/hid/hid-magicmouse.c
@@ -54,6 +54,8 @@ module_param(report_undeciphered, bool, 0644);
 MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state field using a MSC_RAW event");
 
 #define TRACKPAD_REPORT_ID 0x28
+#define TRACKPAD2_USB_REPORT_ID 0x02
+#define TRACKPAD2_BT_REPORT_ID 0x31
 #define MOUSE_REPORT_ID    0x29
 #define DOUBLE_REPORT_ID   0xf7
 /* These definitions are not precise, but they're close enough.  (Bits
@@ -91,6 +93,17 @@ MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state fie
 #define TRACKPAD_RES_Y \
 	((TRACKPAD_MAX_Y - TRACKPAD_MIN_Y) / (TRACKPAD_DIMENSION_Y / 100))
 
+#define TRACKPAD2_DIMENSION_X (float)16000
+#define TRACKPAD2_MIN_X -3678
+#define TRACKPAD2_MAX_X 3934
+#define TRACKPAD2_RES_X \
+	((TRACKPAD2_MAX_X - TRACKPAD2_MIN_X) / (TRACKPAD2_DIMENSION_X / 100))
+#define TRACKPAD2_DIMENSION_Y (float)11490
+#define TRACKPAD2_MIN_Y -2478
+#define TRACKPAD2_MAX_Y 2587
+#define TRACKPAD2_RES_Y \
+	((TRACKPAD2_MAX_Y - TRACKPAD2_MIN_Y) / (TRACKPAD2_DIMENSION_Y / 100))
+
 /**
  * struct magicmouse_sc - Tracks Magic Mouse-specific data.
  * @input: Input device through which we report events.
@@ -183,6 +196,7 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
 {
 	struct input_dev *input = msc->input;
 	int id, x, y, size, orientation, touch_major, touch_minor, state, down;
+	int pressure = 0;
 
 	if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 		id = (tdata[6] << 2 | tdata[5] >> 6) & 0xf;
@@ -194,6 +208,20 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
 		touch_minor = tdata[4];
 		state = tdata[7] & TOUCH_STATE_MASK;
 		down = state != TOUCH_STATE_NONE;
+	} else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
+		id = tdata[8] & 0xf;
+		x = (tdata[1] << 27 | tdata[0] << 19) >> 19;
+		y = -((tdata[3] << 30 | tdata[2] << 22 | tdata[1] << 14) >> 19);
+		size = tdata[6];
+		orientation = (tdata[8] >> 5) - 4;
+		touch_major = tdata[4];
+		touch_minor = tdata[5];
+		/* Add to pressure to prevent libraries such as libinput
+		 * from ignoring low pressure touches
+		 */
+		pressure = tdata[7] + 30;
+		state = tdata[3] & 0xC0;
+		down = state == 0x80;
 	} else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 		id = (tdata[7] << 2 | tdata[6] >> 6) & 0xf;
 		x = (tdata[1] << 27 | tdata[0] << 19) >> 19;
@@ -215,7 +243,8 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
 	/* If requested, emulate a scroll wheel by detecting small
 	 * vertical touch motions.
 	 */
-	if (emulate_scroll_wheel) {
+	if (emulate_scroll_wheel && (input->id.product !=
+			USB_DEVICE_ID_APPLE_MAGICTRACKPAD2)) {
 		unsigned long now = jiffies;
 		int step_x = msc->touches[id].scroll_x - x;
 		int step_y = msc->touches[id].scroll_y - y;
@@ -269,10 +298,14 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
 		input_report_abs(input, ABS_MT_POSITION_X, x);
 		input_report_abs(input, ABS_MT_POSITION_Y, y);
 
+		if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2)
+			input_report_abs(input, ABS_MT_PRESSURE, pressure);
+
 		if (report_undeciphered) {
 			if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
 				input_event(input, EV_MSC, MSC_RAW, tdata[7]);
-			else /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
+			else if (input->id.product !=
+					USB_DEVICE_ID_APPLE_MAGICTRACKPAD2)
 				input_event(input, EV_MSC, MSC_RAW, tdata[8]);
 		}
 	}
@@ -287,6 +320,7 @@ static int magicmouse_raw_event(struct hid_device *hdev,
 
 	switch (data[0]) {
 	case TRACKPAD_REPORT_ID:
+	case TRACKPAD2_BT_REPORT_ID:
 		/* Expect four bytes of prefix, and N*9 bytes of touch data. */
 		if (size < 4 || ((size - 4) % 9) != 0)
 			return 0;
@@ -301,12 +335,22 @@ static int magicmouse_raw_event(struct hid_device *hdev,
 			magicmouse_emit_touch(msc, ii, data + ii * 9 + 4);
 
 		clicks = data[1];
+		break;
+	case TRACKPAD2_USB_REPORT_ID:
+		/* Expect twelve bytes of prefix and N*9 bytes of touch data. */
+		if (size < 12 || ((size - 12) % 9) != 0)
+			return 0;
+		npoints = (size - 12) / 9;
+		if (npoints > 15) {
+			hid_warn(hdev, "invalid size value (%d) for TRACKPAD2_USB_REPORT_ID\n",
+					size);
+			return 0;
+		}
+		msc->ntouches = 0;
+		for (ii = 0; ii < npoints; ii++)
+			magicmouse_emit_touch(msc, ii, data + ii * 9 + 12);
 
-		/* The following bits provide a device specific timestamp. They
-		 * are unused here.
-		 *
-		 * ts = data[1] >> 6 | data[2] << 2 | data[3] << 10;
-		 */
+		clicks = data[1];
 		break;
 	case MOUSE_REPORT_ID:
 		/* Expect six bytes of prefix, and N*8 bytes of touch data. */
@@ -352,6 +396,9 @@ static int magicmouse_raw_event(struct hid_device *hdev,
 		magicmouse_emit_buttons(msc, clicks & 3);
 		input_report_rel(input, REL_X, x);
 		input_report_rel(input, REL_Y, y);
+	} else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
+		input_mt_sync_frame(input);
+		input_report_key(input, BTN_MOUSE, clicks & 1);
 	} else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 		input_report_key(input, BTN_MOUSE, clicks & 1);
 		input_mt_report_pointer_emulation(input, true);
@@ -364,6 +411,7 @@ static int magicmouse_raw_event(struct hid_device *hdev,
 static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hdev)
 {
 	int error;
+	int mt_flags = 0;
 
 	__set_bit(EV_KEY, input->evbit);
 
@@ -380,6 +428,22 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
 			__set_bit(REL_WHEEL, input->relbit);
 			__set_bit(REL_HWHEEL, input->relbit);
 		}
+	} else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
+		/* setting the device name to ensure the same driver settings
+		 * get loaded, whether connected through bluetooth or USB
+		 */
+		input->name = "Apple Inc. Magic Trackpad 2";
+
+		__clear_bit(EV_MSC, input->evbit);
+		__clear_bit(BTN_0, input->keybit);
+		__clear_bit(BTN_RIGHT, input->keybit);
+		__clear_bit(BTN_MIDDLE, input->keybit);
+		__set_bit(BTN_MOUSE, input->keybit);
+		__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
+		__set_bit(BTN_TOOL_FINGER, input->keybit);
+
+		mt_flags = INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED |
+				INPUT_MT_TRACK;
 	} else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 		/* input->keybit is initialized with incorrect button info
 		 * for Magic Trackpad. There really is only one physical
@@ -402,14 +466,13 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
 
 	__set_bit(EV_ABS, input->evbit);
 
-	error = input_mt_init_slots(input, 16, 0);
+	error = input_mt_init_slots(input, 16, mt_flags);
 	if (error)
 		return error;
 	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255 << 2,
 			     4, 0);
 	input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0, 255 << 2,
 			     4, 0);
-	input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
 
 	/* Note: Touch Y position from the device is inverted relative
 	 * to how pointer motion is reported (and relative to how USB
@@ -418,6 +481,7 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
 	 * inverse of the reported Y.
 	 */
 	if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
+		input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
 		input_set_abs_params(input, ABS_MT_POSITION_X,
 				     MOUSE_MIN_X, MOUSE_MAX_X, 4, 0);
 		input_set_abs_params(input, ABS_MT_POSITION_Y,
@@ -427,7 +491,25 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
 				  MOUSE_RES_X);
 		input_abs_set_res(input, ABS_MT_POSITION_Y,
 				  MOUSE_RES_Y);
+	} else if (input->id.product ==  USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
+		input_set_abs_params(input, ABS_MT_PRESSURE, 0, 283, 0, 0);
+		input_set_abs_params(input, ABS_PRESSURE, 0, 283, 0, 0);
+		input_set_abs_params(input, ABS_MT_ORIENTATION, -3, 4, 0, 0);
+		input_set_abs_params(input, ABS_X, TRACKPAD2_MIN_X,
+				     TRACKPAD2_MAX_X, 0, 0);
+		input_set_abs_params(input, ABS_Y, TRACKPAD2_MIN_Y,
+				     TRACKPAD2_MAX_Y, 0, 0);
+		input_set_abs_params(input, ABS_MT_POSITION_X,
+				     TRACKPAD2_MIN_X, TRACKPAD2_MAX_X, 0, 0);
+		input_set_abs_params(input, ABS_MT_POSITION_Y,
+				     TRACKPAD2_MIN_Y, TRACKPAD2_MAX_Y, 0, 0);
+
+		input_abs_set_res(input, ABS_X, TRACKPAD2_RES_X);
+		input_abs_set_res(input, ABS_Y, TRACKPAD2_RES_Y);
+		input_abs_set_res(input, ABS_MT_POSITION_X, TRACKPAD2_RES_X);
+		input_abs_set_res(input, ABS_MT_POSITION_Y, TRACKPAD2_RES_Y);
 	} else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
+		input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
 		input_set_abs_params(input, ABS_X, TRACKPAD_MIN_X,
 				     TRACKPAD_MAX_X, 4, 0);
 		input_set_abs_params(input, ABS_Y, TRACKPAD_MIN_Y,
@@ -447,7 +529,8 @@ static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hd
 
 	input_set_events_per_packet(input, 60);
 
-	if (report_undeciphered) {
+	if (report_undeciphered &&
+	    input->id.product != USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
 		__set_bit(EV_MSC, input->evbit);
 		__set_bit(MSC_RAW, input->mscbit);
 	}
@@ -465,7 +548,8 @@ static int magicmouse_input_mapping(struct hid_device *hdev,
 		msc->input = hi->input;
 
 	/* Magic Trackpad does not give relative data after switching to MT */
-	if (hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD &&
+	if ((hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD ||
+	     hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) &&
 	    field->flags & HID_MAIN_ITEM_RELATIVE)
 		return -1;
 
@@ -494,11 +578,20 @@ static int magicmouse_input_configured(struct hid_device *hdev,
 static int magicmouse_probe(struct hid_device *hdev,
 	const struct hid_device_id *id)
 {
-	const u8 feature[] = { 0xd7, 0x01 };
+	const u8 *feature;
+	const u8 feature_mt[] = { 0xD7, 0x01 };
+	const u8 feature_mt_trackpad2_usb[] = { 0x02, 0x01 };
+	const u8 feature_mt_trackpad2_bt[] = { 0xF1, 0x02, 0x01 };
 	u8 *buf;
 	struct magicmouse_sc *msc;
 	struct hid_report *report;
 	int ret;
+	int feature_size;
+
+	if (id->vendor == USB_VENDOR_ID_APPLE &&
+	    id->product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 &&
+	    hdev->type != HID_TYPE_USBMOUSE)
+		return 0;
 
 	msc = devm_kzalloc(&hdev->dev, sizeof(*msc), GFP_KERNEL);
 	if (msc == NULL) {
@@ -532,7 +625,14 @@ static int magicmouse_probe(struct hid_device *hdev,
 	if (id->product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
 		report = hid_register_report(hdev, HID_INPUT_REPORT,
 			MOUSE_REPORT_ID, 0);
-	else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
+	else if (id->product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
+		if (id->vendor == BT_VENDOR_ID_APPLE)
+			report = hid_register_report(hdev, HID_INPUT_REPORT,
+				TRACKPAD2_BT_REPORT_ID, 0);
+		else /* USB_VENDOR_ID_APPLE */
+			report = hid_register_report(hdev, HID_INPUT_REPORT,
+				TRACKPAD2_USB_REPORT_ID, 0);
+	} else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 		report = hid_register_report(hdev, HID_INPUT_REPORT,
 			TRACKPAD_REPORT_ID, 0);
 		report = hid_register_report(hdev, HID_INPUT_REPORT,
@@ -546,7 +646,20 @@ static int magicmouse_probe(struct hid_device *hdev,
 	}
 	report->size = 6;
 
-	buf = kmemdup(feature, sizeof(feature), GFP_KERNEL);
+	if (id->product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2) {
+		if (id->vendor == BT_VENDOR_ID_APPLE) {
+			feature_size = sizeof(feature_mt_trackpad2_bt);
+			feature = feature_mt_trackpad2_bt;
+		} else { /* USB_VENDOR_ID_APPLE */
+			feature_size = sizeof(feature_mt_trackpad2_usb);
+			feature = feature_mt_trackpad2_usb;
+		}
+	} else {
+		feature_size = sizeof(feature_mt);
+		feature = feature_mt;
+	}
+
+	buf = kmemdup(feature, feature_size, GFP_KERNEL);
 	if (!buf) {
 		ret = -ENOMEM;
 		goto err_stop_hw;
@@ -560,10 +673,10 @@ static int magicmouse_probe(struct hid_device *hdev,
 	 * but there seems to be no other way of switching the mode.
 	 * Thus the super-ugly hacky success check below.
 	 */
-	ret = hid_hw_raw_request(hdev, buf[0], buf, sizeof(feature),
+	ret = hid_hw_raw_request(hdev, buf[0], buf, feature_size,
 				HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 	kfree(buf);
-	if (ret != -EIO && ret != sizeof(feature)) {
+	if (ret != -EIO && ret != feature_size) {
 		hid_err(hdev, "unable to request touch data (%d)\n", ret);
 		goto err_stop_hw;
 	}
@@ -579,6 +692,10 @@ static const struct hid_device_id magic_mice[] = {
 		USB_DEVICE_ID_APPLE_MAGICMOUSE), .driver_data = 0 },
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
 		USB_DEVICE_ID_APPLE_MAGICTRACKPAD), .driver_data = 0 },
+	{ HID_BLUETOOTH_DEVICE(BT_VENDOR_ID_APPLE,
+		USB_DEVICE_ID_APPLE_MAGICTRACKPAD2), .driver_data = 0 },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE,
+		USB_DEVICE_ID_APPLE_MAGICTRACKPAD2), .driver_data = 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, magic_mice);
-- 
2.19.0.444.g18242da7ef-goog