DIGImend · weimens · Aug 15, 2019
diff --git a/hid-uclogic-params.c b/hid-uclogic-params.c
@@ -233,6 +233,87 @@ static int uclogic_params_pen_init_v1(struct uclogic_params_pen *pen,
 	return rc;
 }
 
+/**
+ * uclogic_params_pen_init_mast10() - initialize tablet interface pen
+ * input and retrieve its parameters from the device, using v1 protocol.
+ *
+ * @pen:	Pointer to the pen parameters to initialize (to be
+ *		cleaned up with uclogic_params_pen_cleanup()). Not modified in
+ *		case of error, or if parameters are not found. Cannot be NULL.
+ * @pfound:	Location for a flag which is set to true if the parameters
+ *		were found, and to false if not (e.g. device was
+ *		incompatible). Not modified in case of error. Cannot be NULL.
+ * @hdev:	The HID device of the tablet interface to initialize and get
+ *		parameters from. Cannot be NULL.
+ *
+ * Returns:
+ *	Zero, if successful. A negative errno code on error.
+ */
+static int uclogic_params_pen_init_mast10(struct uclogic_params_pen *pen,
+				      bool *pfound,
+				      struct hid_device *hdev)
+{
+	int rc;
+	bool found = false;
+	/* Buffer for (part of) the string descriptor */
+	__u8 *buf = NULL;
+	/* Minimum descriptor length required, maximum seen so far is 18 */
+	const int len = 12;
+	__u8 *desc_copy_ptr = NULL;
+
+	/* Check arguments */
+	if (pen == NULL || pfound == NULL || hdev == NULL) {
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	/*
+	 * Read string descriptor containing pen input parameters.
+	 * The specific string descriptor and data were discovered by sniffing
+	 * the Windows driver traffic.
+	 * NOTE: This enables fully-functional tablet mode.
+	 */
+	rc = uclogic_params_get_str_desc(&buf, hdev, 100, len);
+	if (rc == -EPIPE) {
+		hid_dbg(hdev,
+			"string descriptor with pen parameters not found, assuming not compatible\n");
+		goto finish;
+	} else if (rc < 0) {
+		hid_err(hdev, "failed retrieving pen parameters: %d\n", rc);
+		goto cleanup;
+	} else if (rc != len) {
+		hid_dbg(hdev,
+			"string descriptor with pen parameters has invalid length (got %d, expected %d), assuming not compatible\n",
+			rc, len);
+		goto finish;
+	}
+
+	kfree(buf);
+	buf = NULL;
+
+	desc_copy_ptr = kmemdup(uclogic_rdesc_mast10_fixed0_arr, uclogic_rdesc_mast10_fixed0_size, GFP_KERNEL);
+	if (desc_copy_ptr == NULL) {
+		rc = -ENOMEM;
+		goto cleanup;
+	}
+
+	/*
+	 * Fill-in the parameters
+	 */
+	memset(pen, 0, sizeof(*pen));
+	pen->desc_ptr = desc_copy_ptr;
+	desc_copy_ptr = NULL;
+	pen->desc_size = uclogic_rdesc_mast10_fixed0_size;
+	found = true;
+finish:
+	*pfound = found;
+	rc = 0;
+cleanup:
+	kfree(desc_copy_ptr);
+	kfree(buf);
+	return rc;
+}
+
 /**
  * uclogic_params_get_le24() - get a 24-bit little-endian number from a
  * buffer.
@@ -989,6 +1070,19 @@ int uclogic_params_init(struct uclogic_params *params,
 		     USB_DEVICE_ID_HUION_TABLET):
 	case VID_PID(USB_VENDOR_ID_UCLOGIC,
 		     USB_DEVICE_ID_YIYNOVA_TABLET):
+		if (hdev->dev_rsize == UCLOGIC_RDESC_MAST10_ORIG0_SIZE &&
+			bInterfaceNumber == 0) {
+			rc = uclogic_params_pen_init_mast10(&p.pen, &found, hdev);
+			if (rc != 0) {
+				hid_err(hdev, "pen probing failed: %d\n", rc);
+				goto cleanup;
+			}
+			if (!found) {
+				hid_warn(hdev, "pen parameters not found");
+				uclogic_params_init_invalid(&p);
+			}
+			break;
+		}
 	case VID_PID(USB_VENDOR_ID_UCLOGIC,
 		     USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_81):
 	case VID_PID(USB_VENDOR_ID_UCLOGIC,

diff --git a/hid-uclogic-rdesc.c b/hid-uclogic-rdesc.c
@@ -827,6 +827,57 @@ const __u8 uclogic_rdesc_xppen_deco01_frame_arr[] = {
 const size_t uclogic_rdesc_xppen_deco01_frame_size =
 			sizeof(uclogic_rdesc_xppen_deco01_frame_arr);
 
+/* Fixed Mast10 report descriptor, interface 0 (stylus) */
+__u8 uclogic_rdesc_mast10_fixed0_arr[] = {
+	0x05, 0x0D,             /*  Usage Page (Digitizer),                 */
+	0x09, 0x02,             /*  Usage (Pen),                            */
+	0xA1, 0x01,             /*  Collection (Application),               */
+	0x85, 0x07,             /*      Report ID (7),                      */
+	0x09, 0x20,             /*      Usage (Stylus),                     */
+	0xA0,                   /*      Collection (Physical),              */
+	0x14,                   /*          Logical Minimum (0),            */
+	0x25, 0x01,             /*          Logical Maximum (1),            */
+	0x75, 0x01,             /*          Report Size (1),                */
+	0x09, 0x42,             /*          Usage (Tip Switch),             */
+	0x09, 0x44,             /*          Usage (Barrel Switch),          */
+	0x09, 0x46,             /*          Usage (Tablet Pick),            */
+	0x95, 0x03,             /*          Report Count (3),               */
+	0x81, 0x02,             /*          Input (Variable),               */
+	0x95, 0x03,             /*          Report Count (3),               */
+	0x81, 0x03,             /*          Input (Constant, Variable),     */
+	0x09, 0x32,             /*          Usage (In Range),               */
+	0x95, 0x01,             /*          Report Count (1),               */
+	0x81, 0x02,             /*          Input (Variable),               */
+	0x95, 0x01,             /*          Report Count (1),               */
+	0x81, 0x03,             /*          Input (Constant, Variable),     */
+	0x75, 0x10,             /*          Report Size (16),               */
+	0x95, 0x01,             /*          Report Count (1),               */
+	0xA4,                   /*          Push,                           */
+	0x05, 0x01,             /*          Usage Page (Desktop),           */
+	0x65, 0x13,             /*          Unit (Inch),                    */
+	0x55, 0xFD,             /*          Unit Exponent (-3),             */
+	0x34,                   /*          Physical Minimum (0),           */
+	0x09, 0x30,             /*          Usage (X),                      */
+	0x26, 0xBE, 0x54,       /*          Logical Maximum (21694),        */
+	0x46, 0x5D, 0x21,       /*          Physical Maximum (8541),        */
+	0x81, 0x02,             /*          Input (Variable),               */
+	0x09, 0x31,             /*          Usage (Y),                      */
+	0x26, 0xF6, 0x34,       /*          Logical Maximum (13558),        */
+	0x46, 0xDA, 0x14,       /*          Physical Maximum (5338),        */
+	0x81, 0x02,             /*          Input (Variable),               */
+	0xB4,                   /*          Pop,                            */
+	0x09, 0x30,             /*          Usage (Tip Pressure),           */
+	0x26, 0xFF, 0x07,       /*          Logical Maximum (2047),         */
+	0x81, 0x02,             /*          Input (Variable),               */
+	0x75, 0x10,             /*          Report Size (16),               */
+	0x95, 0x01,             /*          Report Count (1),               */
+	0x81, 0x03,             /*          Input (Constant, Variable),     */
+	0xC0,                   /*      End Collection,                     */
+	0xC0                    /*  End Collection                          */
+};
+const size_t uclogic_rdesc_mast10_fixed0_size =
+			sizeof(uclogic_rdesc_mast10_fixed0_arr);
+
 /**
  * uclogic_rdesc_template_apply() - apply report descriptor parameters to a
  * report descriptor template, creating a report descriptor. Copies the

diff --git a/hid-uclogic-rdesc.h b/hid-uclogic-rdesc.h
@@ -152,4 +152,11 @@ extern const size_t uclogic_rdesc_ugee_g5_frame_size;
 /* Least-significant bit of Ugee G5 frame rotary encoder state */
 #define UCLOGIC_RDESC_UGEE_G5_FRAME_RE_LSB 38
 
+/* Size of the original descriptors of Mast10 tablet */
+#define UCLOGIC_RDESC_MAST10_ORIG0_SIZE 192
+
+/* Fixed report descriptor for Mast10 tablet */
+extern __u8 uclogic_rdesc_mast10_fixed0_arr[];
+extern const size_t uclogic_rdesc_mast10_fixed0_size;
+
 #endif /* _HID_UCLOGIC_RDESC_H */