HID: Add driver for Razer Blackwidow keyboards

Add a driver to enable the macro keys (M1 - M5) by default, these are
mapped to XF86Tools and XF86Launch5 - XF86Launch8. The driver remaps
them by default to macro keys with an option to retain the old mapping
which users most likely already use as there are many scripts to enable
the macro keys available on Github and other websites.

Signed-off-by: Jelle van der Waa <jvanderwaa@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/Kconfig

@@ -929,6 +929,13 @@ config PLAYSTATION_FF
 	  Say Y here if you would like to enable force feedback support for
 	  PlayStation game controllers.
 
+config HID_RAZER
+	tristate "Razer non-fully HID-compliant devices"
+	depends on HID
+	help
+	Support for Razer devices that are not fully compliant with the
+	HID standard.
+
 config HID_PRIMAX
 	tristate "Primax non-fully HID-compliant devices"
 	depends on HID

drivers/hid/Makefile

@@ -99,6 +99,7 @@ hid-picolcd-$(CONFIG_DEBUG_FS)		+= hid-picolcd_debugfs.o
 obj-$(CONFIG_HID_PLANTRONICS)	+= hid-plantronics.o
 obj-$(CONFIG_HID_PLAYSTATION)	+= hid-playstation.o
 obj-$(CONFIG_HID_PRIMAX)	+= hid-primax.o
+obj-$(CONFIG_HID_RAZER)	+= hid-razer.o
 obj-$(CONFIG_HID_REDRAGON)	+= hid-redragon.o
 obj-$(CONFIG_HID_RETRODE)	+= hid-retrode.o
 obj-$(CONFIG_HID_ROCCAT)	+= hid-roccat.o hid-roccat-common.o \

drivers/hid/hid-ids.h

@@ -1030,6 +1030,9 @@
 #define I2C_PRODUCT_ID_RAYDIUM_3118	0x3118
 
 #define USB_VENDOR_ID_RAZER            0x1532
+#define USB_DEVICE_ID_RAZER_BLACKWIDOW_ULTIMATE   0x010D
+#define USB_DEVICE_ID_RAZER_BLACKWIDOW            0x010e
+#define USB_DEVICE_ID_RAZER_BLACKWIDOW_CLASSIC    0x011b
 #define USB_DEVICE_ID_RAZER_BLADE_14   0x011D
 
 #define USB_VENDOR_ID_REALTEK		0x0bda

drivers/hid/hid-razer.c

@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  HID driver for gaming keys on Razer Blackwidow gaming keyboards
+ *  Macro Key Keycodes: M1 = 191, M2 = 192, M3 = 193, M4 = 194, M5 = 195
+ *
+ *  Copyright (c) 2021 Jelle van der Waa <jvanderwaa@redhat.com>
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/sched.h>
+#include <linux/usb.h>
+#include <linux/wait.h>
+
+#include "hid-ids.h"
+
+#define map_key_clear(c) hid_map_usage_clear(hi, usage, bit, max, EV_KEY, (c))
+
+#define RAZER_BLACKWIDOW_TRANSFER_BUF_SIZE	91
+
+static bool macro_key_remapping = 1;
+module_param(macro_key_remapping, bool, 0644);
+MODULE_PARM_DESC(macro_key_remapping, " on (Y) off (N)");
+
+
+static unsigned char blackwidow_init[RAZER_BLACKWIDOW_TRANSFER_BUF_SIZE] = {
+	0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x04,
+	0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x04, 0x00
+};
+
+static int razer_input_mapping(struct hid_device *hdev,
+		struct hid_input *hi, struct hid_field *field,
+		struct hid_usage *usage, unsigned long **bit, int *max)
+{
+
+	if (!macro_key_remapping)
+		return 0;
+
+	if ((usage->hid & HID_UP_KEYBOARD) != HID_UP_KEYBOARD)
+		return 0;
+
+	switch (usage->hid & ~HID_UP_KEYBOARD) {
+	case 0x68:
+		map_key_clear(KEY_MACRO1);
+		return 1;
+	case 0x69:
+		map_key_clear(KEY_MACRO2);
+		return 1;
+	case 0x6a:
+		map_key_clear(KEY_MACRO3);
+		return 1;
+	case 0x6b:
+		map_key_clear(KEY_MACRO4);
+		return 1;
+	case 0x6c:
+		map_key_clear(KEY_MACRO5);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int razer_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	char *buf;
+	int ret = 0;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return ret;
+
+	/*
+	 * Only send the enable macro keys command for the third device
+	 * identified as mouse input.
+	 */
+	if (hdev->type == HID_TYPE_USBMOUSE) {
+		buf = kmemdup(blackwidow_init, RAZER_BLACKWIDOW_TRANSFER_BUF_SIZE, GFP_KERNEL);
+		if (buf == NULL)
+			return -ENOMEM;
+
+		ret = hid_hw_raw_request(hdev, 0, buf, RAZER_BLACKWIDOW_TRANSFER_BUF_SIZE,
+				HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
+		if (ret != RAZER_BLACKWIDOW_TRANSFER_BUF_SIZE)
+			hid_err(hdev, "failed to enable macro keys: %d\n", ret);
+
+		kfree(buf);
+	}
+
+	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+}
+
+static const struct hid_device_id razer_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_RAZER,
+		USB_DEVICE_ID_RAZER_BLACKWIDOW) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_RAZER,
+		USB_DEVICE_ID_RAZER_BLACKWIDOW_CLASSIC) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_RAZER,
+		USB_DEVICE_ID_RAZER_BLACKWIDOW_ULTIMATE) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, razer_devices);
+
+static struct hid_driver razer_driver = {
+	.name = "razer",
+	.id_table = razer_devices,
+	.input_mapping = razer_input_mapping,
+	.probe = razer_probe,
+};
+module_hid_driver(razer_driver);
+
+MODULE_AUTHOR("Jelle van der Waa <jvanderwaa@redhat.com>");
+MODULE_LICENSE("GPL");