From eaa3bcb06aed1ac1d6d9e3edd3b5f72ea57a6ac0 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 17 Mar 2010 23:06:08 +0100 Subject: USB: serial: generalise write buffer preparation Generalise write buffer preparation. This allows for drivers to manipulate (e.g. add headers) to bulk out data before it is sent. This adds a new function pointer to usb_serial_driver: int (*prepare_write_buffer)(struct usb_serial_port *port, void **dest, size_t size, const void *src, size_t count); The function is generic and can be used with either kfifo-based or multi-urb writes: If *dest is NULL the implementation should allocate dest. If src is NULL the implementation should use the port write fifo. If not set, a generic implementation is used which simply uses memcpy or kfifo_out. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/serial.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/usb/serial.h') diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 2a328376160..a4c99ea390e 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -277,6 +277,9 @@ struct usb_serial_driver { void (*write_bulk_callback)(struct urb *urb); /* Called by the generic read bulk callback */ void (*process_read_urb)(struct urb *urb); + /* Called by the generic write implementation */ + int (*prepare_write_buffer)(struct usb_serial_port *port, + void **dest, size_t size, const void *src, size_t count); }; #define to_usb_serial_driver(d) \ container_of(d, struct usb_serial_driver, driver) @@ -329,6 +332,8 @@ extern void usb_serial_generic_deregister(void); extern int usb_serial_generic_submit_read_urb(struct usb_serial_port *port, gfp_t mem_flags); extern void usb_serial_generic_process_read_urb(struct urb *urb); +extern int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port, + void **dest, size_t size, const void *src, size_t count); extern int usb_serial_handle_sysrq_char(struct tty_struct *tty, struct usb_serial_port *port, unsigned int ch); -- cgit v1.2.3-70-g09d2