HID: wacom: add full support of the Wacom Bamboo PAD

The stylus of this device works just fine out of the box.
The touch is seen by default as a mouse with relative events and some
gestures.
The wireless and the wired version have slightly different firmwares, but
the debug mode 2 on the feature 2 is common to the 2 devices. In this mode,
all the reports are emitted through the debug interface (pen, raw touch
and mouse emulation), so we have to re-route manually the events.

We keep the Pen interface as a HID_GENERIC one because it works, and only
parse the raw touches while discarding the mouse emulation & gestures.

Switching the default in raw mode allows us to have a consistent user
experience accross all the multitouch touchpads (and enable the touch part
of the devices).

Note that the buttons of this devices are reported through the touch
interface. There is no 'Pad' interface. It seemed more natural to have
the BTN_LEFT and BTN_RIGHT reported with the touch because they are
placed under the touch interface and it looks like they belong to the
touch part.
Tested-by: Josep Sanchez Ferreres <josep.sanchez.ferreres@est.fib.upc.edu>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_sys.c

@@ -406,6 +406,9 @@ static int wacom_query_tablet_data(struct hid_device *hdev,
 		else if (features->type == WACOM_27QHDT) {
 			return wacom_set_device_mode(hdev, 131, 3, 2);
 		}
+		else if (features->type == BAMBOO_PAD) {
+			return wacom_set_device_mode(hdev, 2, 2, 2);
+		}
 	} else if (features->device_type == BTN_TOOL_PEN) {
 		if (features->type <= BAMBOO_PT && features->type != WIRELESS) {
 			return wacom_set_device_mode(hdev, 2, 2, 2);
@@ -1425,6 +1428,21 @@ static int wacom_probe(struct hid_device *hdev,
 			goto fail_allocate_inputs;
 	}
 
+	/*
+	 * Bamboo Pad has a generic hid handling for the Pen, and we switch it
+	 * into debug mode for the touch part.
+	 * We ignore the other interfaces.
+	 */
+	if (features->type == BAMBOO_PAD) {
+		if (features->pktlen == WACOM_PKGLEN_PENABLED) {
+			features->type = HID_GENERIC;
+		} else if ((features->pktlen != WACOM_PKGLEN_BPAD_TOUCH) &&
+			   (features->pktlen != WACOM_PKGLEN_BPAD_TOUCH_USB)) {
+			error = -ENODEV;
+			goto fail_shared_data;
+		}
+	}
+
 	/* set the default size in case we do not get them from hid */
 	wacom_set_default_phy(features);
 
@@ -1459,6 +1477,12 @@ static int wacom_probe(struct hid_device *hdev,
 		features->y_max = 4096;
 	}
 
+	/*
+	 * Same thing for Bamboo PAD
+	 */
+	if (features->type == BAMBOO_PAD)
+		features->device_type = BTN_TOOL_FINGER;
+
 	if (hdev->bus == BUS_BLUETOOTH)
 		features->quirks |= WACOM_QUIRK_BATTERY;
 

drivers/hid/wacom_wac.c

@@ -1826,6 +1826,91 @@ static int wacom_bpt_irq(struct wacom_wac *wacom, size_t len)
 	return 0;
 }
 
+static void wacom_bamboo_pad_pen_event(struct wacom_wac *wacom,
+		unsigned char *data)
+{
+	unsigned char prefix;
+
+	/*
+	 * We need to reroute the event from the debug interface to the
+	 * pen interface.
+	 * We need to add the report ID to the actual pen report, so we
+	 * temporary overwrite the first byte to prevent having to kzalloc/kfree
+	 * and memcpy the report.
+	 */
+	prefix = data[0];
+	data[0] = WACOM_REPORT_BPAD_PEN;
+
+	/*
+	 * actually reroute the event.
+	 * No need to check if wacom->shared->pen is valid, hid_input_report()
+	 * will check for us.
+	 */
+	hid_input_report(wacom->shared->pen, HID_INPUT_REPORT, data,
+			 WACOM_PKGLEN_PENABLED, 1);
+
+	data[0] = prefix;
+}
+
+static int wacom_bamboo_pad_touch_event(struct wacom_wac *wacom,
+		unsigned char *data)
+{
+	struct input_dev *input = wacom->input;
+	unsigned char *finger_data, prefix;
+	unsigned id;
+	int x, y;
+	bool valid;
+
+	prefix = data[0];
+
+	for (id = 0; id < wacom->features.touch_max; id++) {
+		valid = !!(prefix & BIT(id)) &&
+			!wacom->shared->stylus_in_proximity;
+
+		input_mt_slot(input, id);
+		input_mt_report_slot_state(input, MT_TOOL_FINGER, valid);
+
+		if (!valid)
+			continue;
+
+		finger_data = data + 1 + id * 3;
+		x = finger_data[0] | ((finger_data[1] & 0x0f) << 8);
+		y = (finger_data[2] << 4) | (finger_data[1] >> 4);
+
+		input_report_abs(input, ABS_MT_POSITION_X, x);
+		input_report_abs(input, ABS_MT_POSITION_Y, y);
+	}
+
+	input_mt_sync_frame(input);
+
+	input_report_key(input, BTN_LEFT, prefix & 0x40);
+	input_report_key(input, BTN_RIGHT, prefix & 0x80);
+
+	/* keep touch state for pen event */
+	wacom->shared->touch_down = !!prefix &&
+				    !wacom->shared->stylus_in_proximity;
+
+	return 1;
+}
+
+static int wacom_bamboo_pad_irq(struct wacom_wac *wacom, size_t len)
+{
+	unsigned char *data = wacom->data;
+
+	if (!((len == WACOM_PKGLEN_BPAD_TOUCH) ||
+	      (len == WACOM_PKGLEN_BPAD_TOUCH_USB)) ||
+	    (data[0] != WACOM_REPORT_BPAD_TOUCH))
+		return 0;
+
+	if (data[1] & 0x01)
+		wacom_bamboo_pad_pen_event(wacom, &data[1]);
+
+	if (data[1] & 0x02)
+		return wacom_bamboo_pad_touch_event(wacom, &data[9]);
+
+	return 0;
+}
+
 static int wacom_wireless_irq(struct wacom_wac *wacom, size_t len)
 {
 	unsigned char *data = wacom->data;
@@ -1962,6 +2047,10 @@ void wacom_wac_irq(struct wacom_wac *wacom_wac, size_t len)
 		sync = wacom_bpt_irq(wacom_wac, len);
 		break;
 
+	case BAMBOO_PAD:
+		sync = wacom_bamboo_pad_irq(wacom_wac, len);
+		break;
+
 	case WIRELESS:
 		sync = wacom_wireless_irq(wacom_wac, len);
 		break;
@@ -2300,6 +2389,13 @@ int wacom_setup_pentouch_input_capabilities(struct input_dev *input_dev,
 					      0, 0);
 		}
 		break;
+	case BAMBOO_PAD:
+		__clear_bit(ABS_MISC, input_dev->absbit);
+		input_mt_init_slots(input_dev, features->touch_max,
+				    INPUT_MT_POINTER);
+		__set_bit(BTN_LEFT, input_dev->keybit);
+		__set_bit(BTN_RIGHT, input_dev->keybit);
+		break;
 	}
 	return 0;
 }
@@ -2953,6 +3049,12 @@ static const struct wacom_features wacom_features_0x30C =
 	{ "Wacom ISDv5 30C", .type = WACOM_24HDT, /* Touch */
 	  .oVid = USB_VENDOR_ID_WACOM, .oPid = 0x30A, .touch_max = 10,
 	  .check_for_hid_type = true, .hid_type = HID_TYPE_USBNONE };
+static const struct wacom_features wacom_features_0x318 =
+	{ "Wacom USB Bamboo PAD", 4095, 4095, /* Touch */
+	  .type = BAMBOO_PAD, 35, 48, .touch_max = 4 };
+static const struct wacom_features wacom_features_0x319 =
+	{ "Wacom Wireless Bamboo PAD", 4095, 4095, /* Touch */
+	  .type = BAMBOO_PAD, 35, 48, .touch_max = 4 };
 static const struct wacom_features wacom_features_0x323 =
 	{ "Wacom Intuos P M", 21600, 13500, 1023, 31,
 	  INTUOSHT, WACOM_INTUOS_RES, WACOM_INTUOS_RES,
@@ -3105,6 +3207,8 @@ const struct hid_device_id wacom_ids[] = {
 	{ USB_DEVICE_WACOM(0x314) },
 	{ USB_DEVICE_WACOM(0x315) },
 	{ USB_DEVICE_WACOM(0x317) },
+	{ USB_DEVICE_WACOM(0x318) },
+	{ USB_DEVICE_WACOM(0x319) },
 	{ USB_DEVICE_WACOM(0x323) },
 	{ USB_DEVICE_WACOM(0x32A) },
 	{ USB_DEVICE_WACOM(0x32B) },

drivers/hid/wacom_wac.h

@@ -33,6 +33,8 @@
 #define WACOM_PKGLEN_MTTPC	40
 #define WACOM_PKGLEN_DTUS	68
 #define WACOM_PKGLEN_PENABLED	 8
+#define WACOM_PKGLEN_BPAD_TOUCH	32
+#define WACOM_PKGLEN_BPAD_TOUCH_USB	64
 
 /* wacom data size per MT contact */
 #define WACOM_BYTES_PER_MT_PACKET	11
@@ -67,6 +69,8 @@
 #define WACOM_REPORT_24HDT		1
 #define WACOM_REPORT_WL			128
 #define WACOM_REPORT_USB		192
+#define WACOM_REPORT_BPAD_PEN		3
+#define WACOM_REPORT_BPAD_TOUCH		16
 
 /* device quirks */
 #define WACOM_QUIRK_MULTI_INPUT		0x0001
@@ -122,6 +126,7 @@ enum {
 	BAMBOO_PT,
 	WACOM_24HDT,
 	WACOM_27QHDT,
+	BAMBOO_PAD,
 	TABLETPC,   /* add new TPC below */
 	TABLETPCE,
 	TABLETPC2FG,