stm32f0: usart: set up process line callback and pass the file pointer

include/console.h

@@ -4,4 +4,6 @@
 
 struct usart_console;
 
-FILE *console_init(void);
+typedef void (* process_line_func)(FILE *fp);
+
+FILE *console_init(process_line_func process_line);

source/drivers/usart_console.c

@@ -19,7 +19,7 @@
 
 struct usart_console {
 	char recv_buf[RECV_BUF_LEN];
-	void (* process_line)(void);
+	void (* process_line)(FILE *fp);
 	FILE *fp;
 	volatile size_t cur, next;
 	uint32_t dev;
@@ -47,7 +47,7 @@ static void usart_isr(struct usart_console *console)
 			scb_reset_system();
 
 		if (console->recv_buf[idx] == '\r' && console->process_line) {
-			console->process_line();
+			console->process_line(console->fp);
 		}
 	}
 }
@@ -169,7 +169,7 @@ static int usart_init(struct usart_console *console)
 	return 0;
 }
 
-FILE *console_init(void)
+FILE *console_init(void (* process_line)(FILE *fp))
 {
 	cookie_io_functions_t fops = {
 		.read = usart_read,
@@ -185,7 +185,7 @@ FILE *console_init(void)
 	console->dev = USART1;
 	console->cur = 0;
 	console->next = 0;
-	console->process_line = NULL;
+	console->process_line = process_line;
 	usart[0] = console;
 
 	usart_init(console);