[PATCH] Serial: Add uart_insert_char()

Add uart_insert_char(), which handles inserting characters into the
flip buffer.  This helper function handles the correct semantics
for handling overrun in addition to inserting normal characters.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index c3fb5984f250..d6025af7efac 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -479,6 +479,25 @@ uart_handle_cts_change(struct uart_port *port, unsigned int status)
         }
 }
 
+#include <linux/tty_flip.h>
+
+static inline void
+uart_insert_char(struct uart_port *port, unsigned int status,
+                 unsigned int overrun, unsigned int ch, unsigned int flag)
+{
+        struct tty_struct *tty = port->info->tty;
+
+        if ((status & port->ignore_status_mask & ~overrun) == 0)
+                tty_insert_flip_char(tty, ch, flag);
+
+        /*
+         * Overrun is special.  Since it's reported immediately,
+         * it doesn't affect the current character.
+         */
+        if (status & ~port->ignore_status_mask & overrun)
+                tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+}
+
 /*
  *      UART_ENABLE_MS - determine if port should enable modem status irqs
  */