Use HID descriptor for razer devices

diff --git a/drivers/hid/hid-razer.c b/drivers/hid/hid-razer.c
index 740df148b0..0c83269d66 100644
--- a/drivers/hid/hid-razer.c
+++ b/drivers/hid/hid-razer.c
@@ -15,31 +15,15 @@ 
 #include <linux/wait.h>
 
 #include "hid-ids.h"
+#include "hid-razer.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 unsigned char set_device_mode[] = {0x00, 0x04, 0x02, 0x00};
 
 static int razer_input_mapping(struct hid_device *hdev,
 		struct hid_input *hi, struct hid_field *field,
@@ -73,35 +57,125 @@  static int razer_input_mapping(struct hid_device *hdev,
 	return 0;
 }
 
+static bool razer_check_control_interface(struct hid_device *hdev)
+{
+	int i;
+	unsigned int hid;
+	struct hid_report *report;
+	struct hid_razer *hid_razer_drvdata;
+
+	hid_razer_drvdata = hid_get_drvdata(hdev);
+
+	list_for_each_entry(report, &hdev->report_enum[HID_FEATURE_REPORT].report_list, list) {
+		for (i = 0; i < report->maxfield; i++) {
+			hid = report->field[i]->usage->hid;
+
+			if ((hid & HID_USAGE_PAGE) == HID_UP_MSVENDOR && (hid & HID_USAGE) == 0x2) {
+				hid_razer_drvdata->report_count = report->field[i]->report_count;
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
+static int razer_control_message(struct hid_device *hdev, unsigned char data_len,
+	unsigned char *data)
+{
+	struct hid_razer *hid_razer_drvdata;
+	unsigned char *full_control_message;
+	unsigned char crc = 0;
+	unsigned int i;
+	unsigned int report_count;
+	int ret;
+
+	if (data_len < 2) {
+		ret = -EINVAL;
+		goto cleanup_and_exit;
+	}
+
+	hid_razer_drvdata = hid_get_drvdata(hdev);
+
+	report_count = hid_razer_drvdata->report_count;
+
+	if (report_count < 2) {
+		ret = -EINVAL;
+		goto cleanup_and_exit;
+	}
+
+	full_control_message = kzalloc(report_count + 1, GFP_KERNEL);
+
+	if (full_control_message == NULL) {
+		ret = -ENOMEM;
+		goto cleanup_and_exit;
+	}
+
+	full_control_message[6] = data_len - 2;
+	memcpy(full_control_message + 7, data, data_len);
+
+	for (i = 2; i < report_count - 2; i++)
+		crc ^= full_control_message[i];
+
+	full_control_message[report_count - 1] = crc;
+
+	ret = hid_hw_raw_request(
+		hdev,
+		0,
+		full_control_message,
+		report_count + 1,
+		HID_FEATURE_REPORT,
+		HID_REQ_SET_REPORT
+	);
+
+	if (ret != report_count + 1) {
+		ret = -EIO;
+		goto cleanup_and_exit;
+	}
+
+cleanup_and_exit:
+	kfree(full_control_message);
+
+	return 0;
+}
+
+
 static int razer_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
-	char *buf;
 	int ret = 0;
+	struct hid_razer *hid_razer_drvdata;
+
+	hid_razer_drvdata = kzalloc(sizeof(struct hid_razer), GFP_KERNEL);
+	if (hid_razer_drvdata == NULL)
+		return -ENOMEM;
+
+	hid_set_drvdata(hdev, hid_razer_drvdata);
 
 	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)
+	if (razer_check_control_interface(hdev)) {
+		ret = razer_control_message(hdev, sizeof(set_device_mode), set_device_mode);
+		if (ret) {
 			hid_err(hdev, "failed to enable macro keys: %d\n", ret);
-
-		kfree(buf);
+			return ret;
+		}
 	}
 
 	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 }
 
+static void razer_remove(struct hid_device *hdev)
+{
+	struct hid_razer *hid_razer_drvdata;
+
+	hid_razer_drvdata = hid_get_drvdata(hdev);
+
+	kfree(hid_razer_drvdata);
+}
+
 static const struct hid_device_id razer_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_RAZER,
 		USB_DEVICE_ID_RAZER_BLACKWIDOW) },
@@ -118,6 +192,7 @@  static struct hid_driver razer_driver = {
 	.id_table = razer_devices,
 	.input_mapping = razer_input_mapping,
 	.probe = razer_probe,
+	.remove = razer_remove,
 };
 module_hid_driver(razer_driver);
 
diff --git a/drivers/hid/hid-razer.h b/drivers/hid/hid-razer.h
new file mode 100644
index 0000000000..d8214ca54b
--- /dev/null
+++ b/drivers/hid/hid-razer.h
@@ -0,0 +1,7 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __HID_RAZER_H
+#define __HID_RAZER_H
+struct hid_razer {
+	unsigned int report_count;
+};
+#endif