HID: microsoft: Convert private data to be a proper struct

In order to be able to have more than just an unsigned long worth of
private data, convert the code to allocate and use a dedicated struct.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Pierre-Loup A. Griffais <pgriffais@valvesoftware.com>
Signed-off-by: Juha Kuikka <juha.kuikka@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-microsoft.c

@@ -30,10 +30,15 @@
 #define MS_DUPLICATE_USAGES	BIT(5)
 #define MS_SURFACE_DIAL		BIT(6)
 
+struct ms_data {
+	unsigned long quirks;
+};
+
 static __u8 *ms_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		unsigned int *rsize)
 {
-	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
+	struct ms_data *ms = hid_get_drvdata(hdev);
+	unsigned long quirks = ms->quirks;
 
 	/*
 	 * Microsoft Wireless Desktop Receiver (Model 1028) has
@@ -159,7 +164,8 @@ static int ms_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 		struct hid_field *field, struct hid_usage *usage,
 		unsigned long **bit, int *max)
 {
-	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
+	struct ms_data *ms = hid_get_drvdata(hdev);
+	unsigned long quirks = ms->quirks;
 
 	if (quirks & MS_ERGONOMY) {
 		int ret = ms_ergonomy_kb_quirk(hi, usage, bit, max);
@@ -185,7 +191,8 @@ static int ms_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 		struct hid_field *field, struct hid_usage *usage,
 		unsigned long **bit, int *max)
 {
-	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
+	struct ms_data *ms = hid_get_drvdata(hdev);
+	unsigned long quirks = ms->quirks;
 
 	if (quirks & MS_DUPLICATE_USAGES)
 		clear_bit(usage->code, *bit);
@@ -196,7 +203,8 @@ static int ms_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 static int ms_event(struct hid_device *hdev, struct hid_field *field,
 		struct hid_usage *usage, __s32 value)
 {
-	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
+	struct ms_data *ms = hid_get_drvdata(hdev);
+	unsigned long quirks = ms->quirks;
 	struct input_dev *input;
 
 	if (!(hdev->claimed & HID_CLAIMED_INPUT) || !field->hidinput ||
@@ -254,9 +262,16 @@ static int ms_event(struct hid_device *hdev, struct hid_field *field,
 static int ms_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
 	unsigned long quirks = id->driver_data;
+	struct ms_data *ms;
 	int ret;
 
-	hid_set_drvdata(hdev, (void *)quirks);
+	ms = devm_kzalloc(&hdev->dev, sizeof(*ms), GFP_KERNEL);
+	if (ms == NULL)
+		return -ENOMEM;
+
+	ms->quirks = quirks;
+
+	hid_set_drvdata(hdev, ms);
 
 	if (quirks & MS_NOGET)
 		hdev->quirks |= HID_QUIRK_NOGET;