[PATCH] HID: Accutouch: Add driver for ELO Accutouch 2216 USB Touchscreens

[Martyn Welch <martyn.welch@collabora.co.uk>]

The Accutouch 2216 is reporting BTN_LEFT/BTN_MOUSE rather than BTM_TOUCH
in it's capabilities, which is what user space expects a touchscreen
device to report. This is causing udev to consider the device to be a
"VMware's USB mouse" rather than as a touchscreen, which results in a
mouse cursor being displayed in Weston.

This patch adds a special driver for the device to correct the
capabilities reported.

Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
---
 drivers/hid/Kconfig         | 12 +++++++++++
 drivers/hid/Makefile        |  1 +
 drivers/hid/hid-accutouch.c | 52 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/hid/hid-core.c      |  1 +
 drivers/hid/hid-ids.h       |  1 +
 5 files changed, 67 insertions(+)
 create mode 100644 drivers/hid/hid-accutouch.c

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 4070b73..ba0d17a 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -98,6 +98,18 @@ config HID_A4TECH
 	---help---
 	Support for A4 tech X5 and WOP-35 / Trust 450L mice.
 
+config HID_ACCUTOUCH
+	tristate "Accutouch touch device"
+	depends on USB_HID
+	---help---
+	  This selects a driver for the Accutouch 2216 touch controller.
+
+	  The driver works around a problem in the reported device capabilities
+	  which causes userspace to detect the device as a mouse rather than
+          a touchscreen.
+
+	  Say Y here if you have a Accutouch 2216 touch controller.
+
 config HID_ACRUX
 	tristate "ACRUX game controller support"
 	depends on HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 4d111f2..48be3ed 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -21,6 +21,7 @@ hid-wiimote-y		:= hid-wiimote-core.o hid-wiimote-modules.o
 hid-wiimote-$(CONFIG_DEBUG_FS)	+= hid-wiimote-debug.o
 
 obj-$(CONFIG_HID_A4TECH)	+= hid-a4tech.o
+obj-$(CONFIG_HID_ACCUTOUCH)	+= hid-accutouch.o
 obj-$(CONFIG_HID_ALPS)		+= hid-alps.o
 obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
 obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
diff --git a/drivers/hid/hid-accutouch.c b/drivers/hid/hid-accutouch.c
new file mode 100644
index 0000000..4e28716
--- /dev/null
+++ b/drivers/hid/hid-accutouch.c
@@ -0,0 +1,52 @@
+/*
+ * HID driver for Elo Accutouch touchscreens
+ *
+ * Copyright (c) 2016, Collabora Ltd.
+ * Copyright (c) 2016, General Electric Company
+ *
+ * based on hid-penmount.c
+ *  Copyright (c) 2014 Christian Gmeiner <christian.gmeiner <at> gmail.com>
+ */
+
+/*
+ * 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/hid.h>
+#include <linux/module.h>
+#include "hid-ids.h"
+
+static int accutouch_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 accutouch_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, USB_DEVICE_ID_ELO_ACCUTOUCH_2216) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, accutouch_devices);
+
+static struct hid_driver accutouch_driver = {
+	.name = "hid-accutouch",
+	.id_table = accutouch_devices,
+	.input_mapping = accutouch_input_mapping,
+};
+
+module_hid_driver(accutouch_driver);
+
+MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk");
+MODULE_DESCRIPTION("Elo Accutouch HID TouchScreen driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index ea36b55..b697491 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1893,6 +1893,7 @@ void hid_disconnect(struct hid_device *hdev)
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELO, USB_DEVICE_ID_ELO_ACCUTOUCH_2216) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_EMS, USB_DEVICE_ID_EMS_TRIO_LINKER_PLUS_II) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_EZKEY, USB_DEVICE_ID_BTC_8193) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_GAMERON, USB_DEVICE_ID_GAMERON_DUAL_PSX_ADAPTOR) },
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 350accf..9472ef2 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -362,6 +362,7 @@
 #define USB_VENDOR_ID_ELO		0x04E7
 #define USB_DEVICE_ID_ELO_TS2515	0x0022
 #define USB_DEVICE_ID_ELO_TS2700	0x0020
+#define USB_DEVICE_ID_ELO_ACCUTOUCH_2216	0x0050
 
 #define USB_VENDOR_ID_EMS		0x2006
 #define USB_DEVICE_ID_EMS_TRIO_LINKER_PLUS_II 0x0118
-- 
1.8.3.1