1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/u_serial.h b/drivers/usb/gadget/function/u_serial.h
new file mode 100644
index 000000000..102a7323a
--- /dev/null
+++ b/drivers/usb/gadget/function/u_serial.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * u_serial.h - interface to USB gadget "serial port"/TTY utilities
+ *
+ * Copyright (C) 2008 David Brownell
+ * Copyright (C) 2008 by Nokia Corporation
+ */
+
+#ifndef __U_SERIAL_H
+#define __U_SERIAL_H
+
+#include <linux/usb/composite.h>
+#include <linux/usb/cdc.h>
+
+#define MAX_U_SERIAL_PORTS	8
+
+struct f_serial_opts {
+	struct usb_function_instance func_inst;
+	u8 port_num;
+};
+
+/*
+ * One non-multiplexed "serial" I/O port ... there can be several of these
+ * on any given USB peripheral device, if it provides enough endpoints.
+ *
+ * The "u_serial" utility component exists to do one thing:  manage TTY
+ * style I/O using the USB peripheral endpoints listed here, including
+ * hookups to sysfs and /dev for each logical "tty" device.
+ *
+ * REVISIT at least ACM could support tiocmget() if needed.
+ *
+ * REVISIT someday, allow multiplexing several TTYs over these endpoints.
+ */
+struct gserial {
+	struct usb_function		func;
+
+	/* port is managed by gserial_{connect,disconnect} */
+	struct gs_port			*ioport;
+
+	struct usb_ep			*in;
+	struct usb_ep			*out;
+
+	/* REVISIT avoid this CDC-ACM support harder ... */
+	struct usb_cdc_line_coding port_line_coding;	/* 9600-8-N-1 etc */
+
+	/* notification callbacks */
+	void (*connect)(struct gserial *p);
+	void (*disconnect)(struct gserial *p);
+	int (*send_break)(struct gserial *p, int duration);
+};
+
+/* utilities to allocate/free request and buffer */
+struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t flags);
+void gs_free_req(struct usb_ep *, struct usb_request *req);
+
+/* management of individual TTY ports */
+int gserial_alloc_line_no_console(unsigned char *port_line);
+int gserial_alloc_line(unsigned char *port_line);
+void gserial_free_line(unsigned char port_line);
+
+#ifdef CONFIG_U_SERIAL_CONSOLE
+
+ssize_t gserial_set_console(unsigned char port_num, const char *page, size_t count);
+ssize_t gserial_get_console(unsigned char port_num, char *page);
+
+#endif /* CONFIG_U_SERIAL_CONSOLE */
+
+/* connect/disconnect is handled by individual functions */
+int gserial_connect(struct gserial *, u8 port_num);
+void gserial_disconnect(struct gserial *);
+void gserial_suspend(struct gserial *p);
+void gserial_resume(struct gserial *p);
+
+/* functions are bound to configurations by a config or gadget driver */
+int gser_bind_config(struct usb_configuration *c, u8 port_num);
+int obex_bind_config(struct usb_configuration *c, u8 port_num);
+
+#endif /* __U_SERIAL_H */