HID: viewsonic: Support PD1011 signature pad

Add support for ViewSonic PD1011 signature (display) pad, which is also
sold by Signotec under a different name.
Signed-off-by: Nikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

drivers/hid/Kconfig

@@ -412,6 +412,12 @@ config HID_WALTOP
 	---help---
 	Support for Waltop tablets.
 
+config HID_VIEWSONIC
+	tristate "ViewSonic/Signotec"
+	depends on HID
+	help
+	  Support for ViewSonic/Signotec PD1011 signature pad.
+
 config HID_GYRATION
 	tristate "Gyration remote control"
 	depends on HID

drivers/hid/Makefile

@@ -114,6 +114,7 @@ obj-$(CONFIG_HID_LED)		+= hid-led.o
 obj-$(CONFIG_HID_XINMO)		+= hid-xinmo.o
 obj-$(CONFIG_HID_ZEROPLUS)	+= hid-zpff.o
 obj-$(CONFIG_HID_ZYDACRON)	+= hid-zydacron.o
+obj-$(CONFIG_HID_VIEWSONIC)	+= hid-viewsonic.o
 
 wacom-objs			:= wacom_wac.o wacom_sys.o
 obj-$(CONFIG_HID_WACOM)		+= wacom.o

drivers/hid/hid-ids.h

@@ -1241,4 +1241,10 @@
 #define USB_VENDOR_ID_UGTIZER			0x2179
 #define USB_DEVICE_ID_UGTIZER_TABLET_GP0610	0x0053
 
+#define USB_VENDOR_ID_VIEWSONIC			0x0543
+#define USB_DEVICE_ID_VIEWSONIC_PD1011		0xe621
+
+#define USB_VENDOR_ID_SIGNOTEC			0x2133
+#define USB_DEVICE_ID_SIGNOTEC_VIEWSONIC_PD1011	0x0018
+
 #endif

drivers/hid/hid-viewsonic.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  HID driver for ViewSonic devices not fully compliant with HID standard
+ *
+ *  Copyright (c) 2017 Nikolai Kondrashov
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+/* Size of the original descriptor of PD1011 signature pad */
+#define PD1011_RDESC_ORIG_SIZE	408
+
+/* Fixed report descriptor of PD1011 signature pad */
+static __u8 pd1011_rdesc_fixed[] = {
+	0x05, 0x0D,             /*  Usage Page (Digitizer),             */
+	0x09, 0x02,             /*  Usage (Pen),                        */
+	0xA1, 0x01,             /*  Collection (Application),           */
+	0x85, 0x02,             /*      Report ID (2),                  */
+	0x09, 0x20,             /*      Usage (Stylus),                 */
+	0xA0,                   /*      Collection (Physical),          */
+	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),                  */
+	0x46, 0x5D, 0x21,       /*          Physical Maximum (8541),    */
+	0x27, 0x80, 0xA9,
+		0x00, 0x00,     /*          Logical Maximum (43392),    */
+	0x81, 0x02,             /*          Input (Variable),           */
+	0x09, 0x31,             /*          Usage (Y),                  */
+	0x46, 0xDA, 0x14,       /*          Physical Maximum (5338),    */
+	0x26, 0xF0, 0x69,       /*          Logical Maximum (27120),    */
+	0x81, 0x02,             /*          Input (Variable),           */
+	0xB4,                   /*          Pop,                        */
+	0x14,                   /*          Logical Minimum (0),        */
+	0x25, 0x01,             /*          Logical Maximum (1),        */
+	0x75, 0x01,             /*          Report Size (1),            */
+	0x95, 0x01,             /*          Report Count (1),           */
+	0x81, 0x03,             /*          Input (Constant, Variable), */
+	0x09, 0x32,             /*          Usage (In Range),           */
+	0x09, 0x42,             /*          Usage (Tip Switch),         */
+	0x95, 0x02,             /*          Report Count (2),           */
+	0x81, 0x02,             /*          Input (Variable),           */
+	0x95, 0x05,             /*          Report Count (5),           */
+	0x81, 0x03,             /*          Input (Constant, Variable), */
+	0x75, 0x10,             /*          Report Size (16),           */
+	0x95, 0x01,             /*          Report Count (1),           */
+	0x09, 0x30,             /*          Usage (Tip Pressure),       */
+	0x15, 0x05,             /*          Logical Minimum (5),        */
+	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                      */
+};
+
+static __u8 *viewsonic_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+				    unsigned int *rsize)
+{
+	switch (hdev->product) {
+	case USB_DEVICE_ID_VIEWSONIC_PD1011:
+	case USB_DEVICE_ID_SIGNOTEC_VIEWSONIC_PD1011:
+		if (*rsize == PD1011_RDESC_ORIG_SIZE) {
+			rdesc = pd1011_rdesc_fixed;
+			*rsize = sizeof(pd1011_rdesc_fixed);
+		}
+		break;
+	}
+
+	return rdesc;
+}
+
+static const struct hid_device_id viewsonic_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_VIEWSONIC,
+				USB_DEVICE_ID_VIEWSONIC_PD1011) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SIGNOTEC,
+				USB_DEVICE_ID_SIGNOTEC_VIEWSONIC_PD1011) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, viewsonic_devices);
+
+static struct hid_driver viewsonic_driver = {
+	.name = "viewsonic",
+	.id_table = viewsonic_devices,
+	.report_fixup = viewsonic_report_fixup,
+};
+module_hid_driver(viewsonic_driver);
+
+MODULE_LICENSE("GPL");