HID: add support for PenMount HID TouchScreen Driver

This patch adds a seperate hid-penmount driver to work
around an issue with the HID report descriptor. The
descriptor does not contain the ContactID usage and as
result the touchscreen is represented as normal mouse
to the system.

This driver maps the button 0 emitted by the touchscreen
to BTN_TOUCH. This makes it possible to use touch events
in userspace.

Signed-off-by: Christian Gmeiner <[e-mail]>
Reviewed-by: Benjamin Tissoires <[e-mail]>
Signed-off-by: Jiri Kosina <[e-mail]>

drivers/hid/Kconfig

···
 	  Say Y here if you have a PantherLord/GreenAsia based game controller
 	  or adapter and want to enable force feedback support for it.
 
+config HID_PENMOUNT
+	tristate "Penmount touch device"
+	depends on USB_HID
+	---help---
+	  This selects a driver for the PenMount 6000 touch controller.
+
+	  The driver works around a problem in the report descript allowing
+	  the userspace to touch events instead of mouse events.
+
+	  Say Y here if you have a Penmount based touch controller.
+
 config HID_PETALYNX
 	tristate "Petalynx Maxter remote control"
 	depends on HID

drivers/hid/Makefile

···
 obj-$(CONFIG_HID_ORTEK)		+= hid-ortek.o
 obj-$(CONFIG_HID_PRODIKEYS)	+= hid-prodikeys.o
 obj-$(CONFIG_HID_PANTHERLORD)	+= hid-pl.o
+obj-$(CONFIG_HID_PENMOUNT)	+= hid-penmount.o
 obj-$(CONFIG_HID_PETALYNX)	+= hid-petalynx.o
 obj-$(CONFIG_HID_PICOLCD)	+= hid-picolcd.o
 hid-picolcd-y			+= hid-picolcd_core.o

drivers/hid/hid-core.c

···
 	{ HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_18) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ORTEK, USB_DEVICE_ID_ORTEK_PKB1700) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ORTEK, USB_DEVICE_ID_ORTEK_WKB2000) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PENMOUNT, USB_DEVICE_ID_PENMOUNT_6000) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PETALYNX, USB_DEVICE_ID_PETALYNX_MAXTER_REMOTE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
 #if IS_ENABLED(CONFIG_HID_ROCCAT)

drivers/hid/hid-ids.h

···
 #define USB_DEVICE_ID_PENMOUNT_PCI	0x3500
 #define USB_DEVICE_ID_PENMOUNT_1610	0x1610
 #define USB_DEVICE_ID_PENMOUNT_1640	0x1640
+#define USB_DEVICE_ID_PENMOUNT_6000	0x6000
 
 #define USB_VENDOR_ID_PETALYNX		0x18b1
 #define USB_DEVICE_ID_PETALYNX_MAXTER_REMOTE	0x0037

drivers/hid/hid-penmount.c

···
+/*
+ *  HID driver for PenMount touchscreens
+ *
+ *  Copyright (c) 2014 Christian Gmeiner <christian.gmeiner <at> gmail.com>
+ *
+ *  based on hid-penmount copyrighted by
+ *    PenMount Touch Solutions <penmount <at> seed.net.tw>
+ */
+
+/*
+ * 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/module.h>
+#include <linux/hid.h>
+#include "hid-ids.h"
+
+static int penmount_input_mapping(struct hid_device *hdev,
+		struct hid_input *hi, struct hid_field *field,
+		struct hid_usage *usage, unsigned long **bit, int *max)
+{
+	if ((usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON) {
+		hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
+		return 1;
+	}
+
+	return 0;
+}
+
+static const struct hid_device_id penmount_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PENMOUNT, USB_DEVICE_ID_PENMOUNT_6000) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, penmount_devices);
+
+static struct hid_driver penmount_driver = {
+	.name = "hid-penmount",
+	.id_table = penmount_devices,
+	.input_mapping = penmount_input_mapping,
+};
+
+module_hid_driver(penmount_driver);
+
+MODULE_AUTHOR("Christian Gmeiner <[e-mail]>");
+MODULE_DESCRIPTION("PenMount HID TouchScreen driver");
+MODULE_LICENSE("GPL");