[PATCH] Add Force Feedback support for EMS Trio Linker Plus II

[Ignaz Forster <ignaz.forster@gmx.de>]

This patch adds Force Feedback support for the EMS Trio Linker Plus II.

The device has connections for GameCube, PlayStation 2 and Dreamcast
controllers, however Force Feedback is only supported for PS2 and GC
controllers.
When using a PS2 controller it may be necessary to press the "Analog"
button to enable support for both motors (this behavior is identical to
the Windows driver, I have found no way to avoid that).


Signed-off-by: Ignaz Forster <ignaz.forster@gmx.de>
---
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 3052e29..3134112 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -150,6 +150,22 @@ config DRAGONRISE_FF
 	Say Y here if you want to enable force feedback support for DragonRise Inc.
 	game controllers.
 
+config HID_EMS
+	tristate "EMS Production Ltd. support"
+	depends on USB_HID
+	---help---
+	Say Y here if you have EMS Production Ltd. game controllers.
+
+config EMS_FF
+	bool "EMS Production Inc. force feedback support"
+	depends on HID_EMS
+	select INPUT_FF_MEMLESS
+	---help---
+	Say Y here if you want to enable force feedback support for devices by
+	EMS Production Ltd.
+	Currently the following devices are known to be supported:
+	 - Trio Linker Plus II
+
 config HID_EGALAX
 	tristate "eGalax multi-touch panel"
 	depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index c335605..7680063 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_HID_CHERRY)	+= hid-cherry.o
 obj-$(CONFIG_HID_CHICONY)	+= hid-chicony.o
 obj-$(CONFIG_HID_CYPRESS)	+= hid-cypress.o
 obj-$(CONFIG_HID_DRAGONRISE)	+= hid-drff.o
+obj-$(CONFIG_HID_EMS)		+= hid-emsff.o
 obj-$(CONFIG_HID_EGALAX)	+= hid-egalax.o
 obj-$(CONFIG_HID_ELECOM)	+= hid-elecom.o
 obj-$(CONFIG_HID_EZKEY)		+= hid-ezkey.o
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 515345b..efffb78 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1301,6 +1301,7 @@ static const struct hid_device_id hid_blacklist[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DWAV, USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_DWAV, USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH1) },
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
+	{ 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) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_GAMERON, USB_DEVICE_ID_GAMERON_DUAL_PCS_ADAPTOR) },
diff --git a/drivers/hid/hid-emsff.c b/drivers/hid/hid-emsff.c
index e69de29..c61b192 100644
--- a/drivers/hid/hid-emsff.c
+++ b/drivers/hid/hid-emsff.c
@@ -0,0 +1,162 @@
+/*
+ *  Force feedback support for EMS Trio Linker Plus II
+ *
+ *  Copyright (c) 2010 Ignaz Forster <ignaz.forster@gmx.de>
+ */
+
+/*
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+
+#include "hid-ids.h"
+#include "usbhid/usbhid.h"
+
+struct emsff_device {
+	struct hid_report *report;
+};
+
+static int emsff_play(struct input_dev *dev, void *data,
+			 struct ff_effect *effect)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct emsff_device *emsff = data;
+	int weak, strong;
+
+	weak = effect->u.rumble.weak_magnitude;
+	strong = effect->u.rumble.strong_magnitude;
+
+	dbg_hid("called with 0x%04x 0x%04x\n", strong, weak);
+
+	weak = weak * 0xff / 0xffff;
+	strong = strong * 0xff / 0xffff;
+
+	emsff->report->field[0]->value[1] = weak;
+	emsff->report->field[0]->value[2] = strong;
+
+	dbg_hid("running with 0x%02x 0x%02x\n", strong, weak);
+	usbhid_submit_report(hid, emsff->report, USB_DIR_OUT);
+
+	return 0;
+}
+
+static int emsff_init(struct hid_device *hid)
+{
+	struct emsff_device *emsff;
+	struct hid_report *report;
+	struct hid_input *hidinput = list_first_entry(&hid->inputs,
+						struct hid_input, list);
+	struct list_head *report_list =
+			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
+	struct input_dev *dev = hidinput->input;
+	int error;
+
+	if (list_empty(report_list)) {
+		dev_err(&hid->dev, "no output reports found\n");
+		return -ENODEV;
+	}
+
+	report = list_first_entry(report_list, struct hid_report, list);
+	if (report->maxfield < 1) {
+		dev_err(&hid->dev, "no fields in the report\n");
+		return -ENODEV;
+	}
+
+	if (report->field[0]->report_count < 7) {
+		dev_err(&hid->dev, "not enough values in the field\n");
+		return -ENODEV;
+	}
+
+	emsff = kzalloc(sizeof(struct emsff_device), GFP_KERNEL);
+	if (!emsff)
+		return -ENOMEM;
+
+	set_bit(FF_RUMBLE, dev->ffbit);
+
+	error = input_ff_create_memless(dev, emsff, emsff_play);
+	if (error) {
+		kfree(emsff);
+		return error;
+	}
+
+	emsff->report = report;
+	emsff->report->field[0]->value[0] = 0x01;
+	emsff->report->field[0]->value[1] = 0x00;
+	emsff->report->field[0]->value[2] = 0x00;
+	emsff->report->field[0]->value[3] = 0x00;
+	emsff->report->field[0]->value[4] = 0x00;
+	emsff->report->field[0]->value[5] = 0x00;
+	emsff->report->field[0]->value[6] = 0x00;
+	usbhid_submit_report(hid, emsff->report, USB_DIR_OUT);
+
+	dev_info(&hid->dev, "force feedback for EMS based devices by "
+	       "Ignaz Forster <ignaz.forster@gmx.de>\n");
+
+	return 0;
+}
+
+static int ems_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		dev_err(&hdev->dev, "parse failed\n");
+		goto err;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
+	if (ret) {
+		dev_err(&hdev->dev, "hw start failed\n");
+		goto err;
+	}
+
+	emsff_init(hdev);
+
+	return 0;
+err:
+	return ret;
+}
+
+static const struct hid_device_id ems_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_EMS, 0x118) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, ems_devices);
+
+static struct hid_driver ems_driver = {
+	.name = "hkems",
+	.id_table = ems_devices,
+	.probe = ems_probe,
+};
+
+static int ems_init(void)
+{
+	return hid_register_driver(&ems_driver);
+}
+
+static void ems_exit(void)
+{
+	hid_unregister_driver(&ems_driver);
+}
+
+module_init(ems_init);
+module_exit(ems_exit);
+MODULE_LICENSE("GPL");
+
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 3341baa..5175001 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -203,6 +203,9 @@
 #define USB_VENDOR_ID_ELO		0x04E7
 #define USB_DEVICE_ID_ELO_TS2700	0x0020
 
+#define USB_VENDOR_ID_EMS		0x2006
+#define USB_DEVICE_ID_EMS_TRIO_LINKER_PLUS_II 0x0118
+
 #define USB_VENDOR_ID_ESSENTIAL_REALITY	0x0d7f
 #define USB_DEVICE_ID_ESSENTIAL_REALITY_P5 0x0100
 
-- 
Ignaz Forster <ignaz.forster@gmx.de>