HID: Add WinWing Orion2 throttle support

WinWing Orion2 throttle works with Linux out of box,
but the kernel sees only 16 of 47 buttons on the throttle base.

This module enables all buttons, and also adds LED controls.

Button numbers 0 .. 63 on Orion2 are reserved for throttle grip;
the throttle base buttons have numbers 64 .. 110.

Linux kernel HID subsystem only supports up to 80 buttons.

Remap throttle base buttons to numbers 32 .. 78,
reserving only numbers 0 .. 31 for buttons on the grip handle.

Changes since v2:
   - Fixed automatic line wraps added by mail client

Changes since v1:
   - Fixed formatting of descriptor byte array;
   - Using product codes of Winwing grips in config.

Signed-off-by: Ivan Gorinov <ivan.gorinov@jobyaviation.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

drivers/hid/Kconfig

@@ -1236,6 +1236,22 @@ config HID_WIIMOTE
 	To compile this driver as a module, choose M here: the
 	module will be called hid-wiimote.
 
+config HID_WINWING
+	tristate "WinWing Orion2 throttle support"
+	depends on USB_HID
+	depends on NEW_LEDS
+	depends on LEDS_CLASS
+	help
+	  Support for WinWing Orion2 throttle base with the following grips:
+
+	    * TGRIP-16EX
+	    * TGRIP-18
+
+	  This driver enables all buttons and switches on the throttle base.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-winwing.
+
 config HID_XINMO
 	tristate "Xin-Mo non-fully compliant devices"
 	help

drivers/hid/Makefile

@@ -150,6 +150,7 @@ wacom-objs			:= wacom_wac.o wacom_sys.o
 obj-$(CONFIG_HID_WACOM)		+= wacom.o
 obj-$(CONFIG_HID_WALTOP)	+= hid-waltop.o
 obj-$(CONFIG_HID_WIIMOTE)	+= hid-wiimote.o
+obj-$(CONFIG_HID_WINWING)	+= hid-winwing.o
 obj-$(CONFIG_HID_SENSOR_HUB)	+= hid-sensor-hub.o
 obj-$(CONFIG_HID_SENSOR_CUSTOM_SENSOR)	+= hid-sensor-custom.o
 

drivers/hid/hid-winwing.c

@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * HID driver for WinWing Orion 2 throttle
+ *
+ * Copyright (c) 2023 Ivan Gorinov
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/hidraw.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+#define MAX_REPORT 16
+
+struct winwing_led {
+	struct led_classdev cdev;
+	struct hid_device *hdev;
+	int number;
+};
+
+struct winwing_led_info {
+	int number;
+	int max_brightness;
+	const char *led_name;
+};
+
+static struct winwing_led_info led_info[3] = {
+	{ 0, 255, "backlight" },
+	{ 1, 1, "a-a" },
+	{ 2, 1, "a-g" },
+};
+
+struct winwing_drv_data {
+	struct hid_device *hdev;
+	__u8 *report_buf;
+	struct mutex lock;
+	unsigned int num_leds;
+	struct winwing_led leds[];
+};
+
+static int winwing_led_write(struct led_classdev *cdev,
+		enum led_brightness br)
+{
+	struct winwing_led *led = (struct winwing_led *) cdev;
+	struct winwing_drv_data *data = hid_get_drvdata(led->hdev);
+	__u8 *buf = data->report_buf;
+	int ret;
+
+	mutex_lock(&data->lock);
+
+	buf[0] = 0x02;
+	buf[1] = 0x60;
+	buf[2] = 0xbe;
+	buf[3] = 0x00;
+	buf[4] = 0x00;
+	buf[5] = 0x03;
+	buf[6] = 0x49;
+	buf[7] = led->number;
+	buf[8] = br;
+	buf[9] = 0x00;
+	buf[10] = 0;
+	buf[11] = 0;
+	buf[12] = 0;
+	buf[13] = 0;
+
+	ret = hid_hw_output_report(led->hdev, buf, 14);
+
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int winwing_init_led(struct hid_device *hdev,
+		struct input_dev *input)
+{
+	struct winwing_drv_data *data;
+	struct winwing_led *led;
+	int ret;
+	int i;
+
+	size_t data_size = struct_size(data, leds, 3);
+
+	data = devm_kzalloc(&hdev->dev, data_size, GFP_KERNEL);
+
+	if (!data)
+		return -ENOMEM;
+
+	data->report_buf = devm_kmalloc(&hdev->dev, MAX_REPORT, GFP_KERNEL);
+
+	if (!data->report_buf)
+		return -ENOMEM;
+
+	for (i = 0; i < 3; i += 1) {
+		struct winwing_led_info *info = &led_info[i];
+
+		led = &data->leds[i];
+		led->hdev = hdev;
+		led->number = info->number;
+		led->cdev.max_brightness = info->max_brightness;
+		led->cdev.brightness_set_blocking = winwing_led_write;
+		led->cdev.flags = LED_HW_PLUGGABLE;
+		led->cdev.name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
+						"%s::%s",
+						dev_name(&input->dev),
+						info->led_name);
+
+		ret = devm_led_classdev_register(&hdev->dev, &led->cdev);
+		if (ret)
+			return ret;
+	}
+
+	hid_set_drvdata(hdev, data);
+
+	return ret;
+}
+
+static int winwing_probe(struct hid_device *hdev,
+		const struct hid_device_id *id)
+{
+	unsigned int minor;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hdev, "hw start failed\n");
+		return ret;
+	}
+
+	minor = ((struct hidraw *) hdev->hidraw)->minor;
+
+	return 0;
+}
+
+static int winwing_input_configured(struct hid_device *hdev,
+		struct hid_input *hidinput)
+{
+	int ret;
+
+	ret = winwing_init_led(hdev, hidinput->input);
+
+	if (ret)
+		hid_err(hdev, "led init failed\n");
+
+	return ret;
+}
+
+static __u8 original_rdesc_buttons[] = {
+	0x05, 0x09, 0x19, 0x01, 0x29, 0x6F,
+	0x15, 0x00, 0x25, 0x01, 0x35, 0x00,
+	0x45, 0x01, 0x75, 0x01, 0x95, 0x6F,
+	0x81, 0x02, 0x75, 0x01, 0x95, 0x01,
+	0x81, 0x01
+};
+
+/*
+ * HID report descriptor shows 111 buttons, which exceeds maximum
+ * number of buttons (80) supported by Linux kernel HID subsystem.
+ *
+ * This module skips numbers 32-63, unused on some throttle grips.
+ */
+
+static __u8 *winwing_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
+{
+	int sig_length = sizeof(original_rdesc_buttons);
+	int unused_button_numbers = 32;
+
+	if (*rsize < 34)
+		return rdesc;
+
+	if (memcmp(rdesc + 8, original_rdesc_buttons, sig_length) == 0) {
+
+		/* Usage Maximum */
+		rdesc[13] -= unused_button_numbers;
+
+		/*  Report Count for buttons */
+		rdesc[25] -= unused_button_numbers;
+
+		/*  Report Count for padding [HID1_11, 6.2.2.9] */
+		rdesc[31] += unused_button_numbers;
+
+		hid_info(hdev, "winwing descriptor fixed\n");
+	}
+
+	return rdesc;
+}
+
+static int winwing_raw_event(struct hid_device *hdev,
+		struct hid_report *report, u8 *raw_data, int size)
+{
+	if (size >= 15) {
+		/* Skip buttons 32 .. 63 */
+		memmove(raw_data + 5, raw_data + 9, 6);
+
+		/* Clear the padding */
+		memset(raw_data + 11, 0, 4);
+	}
+
+	return 0;
+}
+
+static const struct hid_device_id winwing_devices[] = {
+	{ HID_USB_DEVICE(0x4098, 0xbe62) },  /* TGRIP-18 */
+	{ HID_USB_DEVICE(0x4098, 0xbe68) },  /* TGRIP-16EX */
+	{}
+};
+
+MODULE_DEVICE_TABLE(hid, winwing_devices);
+
+static struct hid_driver winwing_driver = {
+	.name = "winwing",
+	.id_table = winwing_devices,
+	.probe = winwing_probe,
+	.input_configured = winwing_input_configured,
+	.report_fixup = winwing_report_fixup,
+	.raw_event = winwing_raw_event,
+};
+module_hid_driver(winwing_driver);
+
+MODULE_LICENSE("GPL");