usb: provide typedefs for all the function callbacks.

This makes it easier to read for most people, and makes it substantially
easier to review changes in the function signatures themselves at a
later date.

include/libopencm3/usb/usbd.h

@@ -75,10 +75,19 @@ extern void usbd_register_resume_callback(usbd_device *usbd_dev,
 extern void usbd_register_sof_callback(usbd_device *usbd_dev,
 				       void (*callback)(void));
 
+typedef int (*usbd_control_complete_callback)(usbd_device *usbd_dev,
+		struct usb_setup_data *req);
+
 typedef int (*usbd_control_callback)(usbd_device *usbd_dev,
 		struct usb_setup_data *req, uint8_t **buf, uint16_t *len,
-		void (**complete)(usbd_device *usbd_dev,
-				  struct usb_setup_data *req));
+		usbd_control_complete_callback *complete);
+
+typedef void (*usbd_set_config_callback)(usbd_device *usbd_dev, uint16_t wValue);
+
+typedef void (*usbd_set_altsetting_callback)(usbd_device *usbd_dev,
+		uint16_t wIndex, uint16_t wValue);
+
+typedef void (*usbd_endpoint_callback)(usbd_device *usbd_dev, uint8_t ep);
 
 /* <usb_control.c> */
 extern int usbd_register_control_callback(usbd_device *usbd_dev, uint8_t type,
@@ -87,18 +96,17 @@ extern int usbd_register_control_callback(usbd_device *usbd_dev, uint8_t type,
 
 /* <usb_standard.c> */
 extern int usbd_register_set_config_callback(usbd_device *usbd_dev,
-	void (*callback)(usbd_device *usbd_dev, uint16_t wValue));
+					  usbd_set_config_callback callback);
 
 extern void usbd_register_set_altsetting_callback(usbd_device *usbd_dev,
-						  void (*callback)(usbd_device *usbd_dev, uint16_t wIndex, uint16_t wValue));
+					  usbd_set_altsetting_callback callback);
 
 /* Functions to be provided by the hardware abstraction layer */
 extern void usbd_poll(usbd_device *usbd_dev);
 extern void usbd_disconnect(usbd_device *usbd_dev, bool disconnected);
 
 extern void usbd_ep_setup(usbd_device *usbd_dev, uint8_t addr, uint8_t type,
-		uint16_t max_size,
-		void (*callback)(usbd_device *usbd_dev, uint8_t ep));
+		uint16_t max_size, usbd_endpoint_callback callback);
 
 extern uint16_t usbd_ep_write_packet(usbd_device *usbd_dev, uint8_t addr,
 				const void *buf, uint16_t len);

lib/usb/usb.c

@@ -143,8 +143,7 @@ void usbd_disconnect(usbd_device *usbd_dev, bool disconnected)
 }
 
 void usbd_ep_setup(usbd_device *usbd_dev, uint8_t addr, uint8_t type,
-		   uint16_t max_size,
-		   void (*callback)(usbd_device *usbd_dev, uint8_t ep))
+		   uint16_t max_size, usbd_endpoint_callback callback)
 {
 	usbd_dev->driver->ep_setup(usbd_dev, addr, type, max_size, callback);
 }

lib/usb/usb_msc.c

@@ -708,7 +708,7 @@ static void msc_data_tx_cb(usbd_device *usbd_dev, uint8_t ep)
  */
 static int msc_control_request(usbd_device *usbd_dev,
 				struct usb_setup_data *req, uint8_t **buf, uint16_t *len,
-				void (**complete)(usbd_device *usbd_dev, struct usb_setup_data *req))
+				usbd_control_complete_callback *complete)
 {
 	(void)complete;
 	(void)usbd_dev;

lib/usb/usb_private.h

@@ -73,8 +73,7 @@ struct _usbd_device {
 		struct usb_setup_data req __attribute__((aligned(4)));
 		uint8_t *ctrl_buf;
 		uint16_t ctrl_len;
-		void (*complete)(usbd_device *usbd_dev,
-				 struct usb_setup_data *req);
+		usbd_control_complete_callback complete;
 	} control_state;
 
 	struct user_control_callback {
@@ -83,14 +82,12 @@ struct _usbd_device {
 		uint8_t type_mask;
 	} user_control_callback[MAX_USER_CONTROL_CALLBACK];
 
-	void (*user_callback_ctr[8][3])(usbd_device *usbd_dev, uint8_t ea);
+	usbd_endpoint_callback user_callback_ctr[8][3];
 
 	/* User callback function for some standard USB function hooks */
-	void (*user_callback_set_config[MAX_USER_SET_CONFIG_CALLBACK])
-				(usbd_device *usbd_dev, uint16_t wValue);
+	usbd_set_config_callback user_callback_set_config[MAX_USER_SET_CONFIG_CALLBACK];
 
-	void (*user_callback_set_altsetting)(usbd_device *usbd_dev,
-					     uint16_t wIndex, uint16_t wValue);
+	usbd_set_altsetting_callback user_callback_set_altsetting;
 
 	const struct _usbd_driver *driver;
 
@@ -144,8 +141,7 @@ struct _usbd_driver {
 	usbd_device *(*init)(void);
 	void (*set_address)(usbd_device *usbd_dev, uint8_t addr);
 	void (*ep_setup)(usbd_device *usbd_dev, uint8_t addr, uint8_t type,
-			 uint16_t max_size,
-			 void (*cb)(usbd_device *usbd_dev, uint8_t ep));
+			 uint16_t max_size, usbd_endpoint_callback cb);
 	void (*ep_reset)(usbd_device *usbd_dev);
 	void (*ep_stall_set)(usbd_device *usbd_dev, uint8_t addr,
 			     uint8_t stall);

lib/usb/usb_standard.c

@@ -40,8 +40,7 @@ LGPL License Terms @ref lgpl_license
 #include "usb_private.h"
 
 int usbd_register_set_config_callback(usbd_device *usbd_dev,
-				       void (*callback)(usbd_device *usbd_dev,
-				       uint16_t wValue))
+				       usbd_set_config_callback callback)
 {
 	int i;
 
@@ -57,8 +56,7 @@ int usbd_register_set_config_callback(usbd_device *usbd_dev,
 }
 
 void usbd_register_set_altsetting_callback(usbd_device *usbd_dev,
-					   void (*callback)(usbd_device *usbd_dev,
-							    uint16_t wIndex, uint16_t wValue))
+					   usbd_set_altsetting_callback callback)
 {
 	usbd_dev->user_callback_set_altsetting = callback;
 }