serial: Factor out uart_poll_timeout() from 8250 driver

Soon we will use that handy function in the altera_uart driver.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 563e23400913..ac48082f3559 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -411,6 +411,14 @@ unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios
                                 unsigned int max);
 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
 
+/* Base timer interval for polling */
+static inline int uart_poll_timeout(struct uart_port *port)
+{
+        int timeout = port->timeout;
+
+        return timeout > 6 ? (timeout / 2 - 2) : 1;
+}
+
 /*
  * Console helpers.
  */