HID: export hid_report_type to uapi

When we are dealing with eBPF, we need to have access to the report type.
Currently our implementation differs from the USB standard, making it
impossible for users to know the exact value besides hardcoding it
themselves.

And instead of a blank define, convert it as an enum.

Note that we need to also do change in the ll_driver API, but given
that this will have a wider impact outside of this tree, we leave this
as a TODO for the future.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220902132938.2409206-10-benjamin.tissoires@redhat.com

drivers/hid/hid-core.c

@@ -55,7 +55,7 @@ MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle
  */
 
 struct hid_report *hid_register_report(struct hid_device *device,
-				       unsigned int type, unsigned int id,
+				       enum hid_report_type type, unsigned int id,
 				       unsigned int application)
 {
 	struct hid_report_enum *report_enum = device->report_enum + type;
@@ -967,7 +967,7 @@ static const char * const hid_report_names[] = {
  * parsing.
  */
 struct hid_report *hid_validate_values(struct hid_device *hid,
-				       unsigned int type, unsigned int id,
+				       enum hid_report_type type, unsigned int id,
 				       unsigned int field_index,
 				       unsigned int report_counts)
 {
@@ -1954,8 +1954,8 @@ out:
 }
 EXPORT_SYMBOL_GPL(__hid_request);
 
-int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
-		int interrupt)
+int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
+			 int interrupt)
 {
 	struct hid_report_enum *report_enum = hid->report_enum + type;
 	struct hid_report *report;
@@ -2019,7 +2019,8 @@ EXPORT_SYMBOL_GPL(hid_report_raw_event);
  *
  * This is data entry for lower layers.
  */
-int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
+int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
+		     int interrupt)
 {
 	struct hid_report_enum *report_enum;
 	struct hid_driver *hdrv;
@@ -2377,7 +2378,7 @@ EXPORT_SYMBOL_GPL(hid_hw_request);
  */
 int hid_hw_raw_request(struct hid_device *hdev,
 		       unsigned char reportnum, __u8 *buf,
-		       size_t len, unsigned char rtype, int reqtype)
+		       size_t len, enum hid_report_type rtype, int reqtype)
 {
 	if (len < 1 || len > HID_MAX_BUFFER_SIZE || !buf)
 		return -EINVAL;

include/linux/hid.h

@@ -314,15 +314,6 @@ struct hid_item {
 #define HID_BAT_ABSOLUTESTATEOFCHARGE	0x00850065
 
 #define HID_VD_ASUS_CUSTOM_MEDIA_KEYS	0xff310076
-/*
- * HID report types --- Ouch! HID spec says 1 2 3!
- */
-
-#define HID_INPUT_REPORT	0
-#define HID_OUTPUT_REPORT	1
-#define HID_FEATURE_REPORT	2
-
-#define HID_REPORT_TYPES	3
 
 /*
  * HID connect requests
@@ -509,7 +500,7 @@ struct hid_report {
 	struct list_head hidinput_list;
 	struct list_head field_entry_list;		/* ordered list of input fields */
 	unsigned int id;				/* id of this report */
-	unsigned int type;				/* report type */
+	enum hid_report_type type;			/* report type */
 	unsigned int application;			/* application usage for this report */
 	struct hid_field *field[HID_MAX_FIELDS];	/* fields of the report */
 	struct hid_field_entry *field_entries;		/* allocated memory of input field_entry */
@@ -926,7 +917,8 @@ extern int hidinput_connect(struct hid_device *hid, unsigned int force);
 extern void hidinput_disconnect(struct hid_device *);
 
 int hid_set_field(struct hid_field *, unsigned, __s32);
-int hid_input_report(struct hid_device *, int type, u8 *, u32, int);
+int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
+		     int interrupt);
 struct hid_field *hidinput_get_led_field(struct hid_device *hid);
 unsigned int hidinput_count_leds(struct hid_device *hid);
 __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code);
@@ -935,11 +927,11 @@ int __hid_request(struct hid_device *hid, struct hid_report *rep, int reqtype);
 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags);
 struct hid_device *hid_allocate_device(void);
 struct hid_report *hid_register_report(struct hid_device *device,
-				       unsigned int type, unsigned int id,
+				       enum hid_report_type type, unsigned int id,
 				       unsigned int application);
 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size);
 struct hid_report *hid_validate_values(struct hid_device *hid,
-				       unsigned int type, unsigned int id,
+				       enum hid_report_type type, unsigned int id,
 				       unsigned int field_index,
 				       unsigned int report_counts);
 
@@ -1111,7 +1103,7 @@ void hid_hw_request(struct hid_device *hdev,
 		    struct hid_report *report, int reqtype);
 int hid_hw_raw_request(struct hid_device *hdev,
 		       unsigned char reportnum, __u8 *buf,
-		       size_t len, unsigned char rtype, int reqtype);
+		       size_t len, enum hid_report_type rtype, int reqtype);
 int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len);
 
 /**
@@ -1184,8 +1176,8 @@ static inline u32 hid_report_len(struct hid_report *report)
 	return DIV_ROUND_UP(report->size, 8) + (report->id > 0);
 }
 
-int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
-		int interrupt);
+int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
+			 int interrupt);
 
 /* HID quirks API */
 unsigned long hid_lookup_quirk(const struct hid_device *hdev);

include/uapi/linux/hid.h

@@ -42,6 +42,18 @@
 #define USB_INTERFACE_PROTOCOL_KEYBOARD	1
 #define USB_INTERFACE_PROTOCOL_MOUSE	2
 
+/*
+ * HID report types --- Ouch! HID spec says 1 2 3!
+ */
+
+enum hid_report_type {
+	HID_INPUT_REPORT		= 0,
+	HID_OUTPUT_REPORT		= 1,
+	HID_FEATURE_REPORT		= 2,
+
+	HID_REPORT_TYPES,
+};
+
 /*
  * HID class requests
  */