m68knommu: fix coldfire tcdrain

Fix tcdrain on coldfire uarts.
Currently with coldfire uarts tcdrain returns without waiting for txempty,
because (tx)fifosize is 0.  Fix that and call uart_update_timeout when
setting the baud rate, otherwise tcdrain will wait for an half our :)
Also constify mcf_uart_ops.

Signed-off-by: Philippe De Muyter <[email protected]>
Signed-off-by: Greg Ungerer <[email protected]>

Author: phdm

arch/m68k/include/asm/mcfuart.h

@@ -212,5 +212,10 @@ struct mcf_platform_uart {
 #define	MCFUART_URF_RXS		0xc0		/* Receiver status */
 #endif
 
+#if defined(CONFIG_M5272)
+#define MCFUART_TXFIFOSIZE	25
+#else
+#define MCFUART_TXFIFOSIZE	1
+#endif
 /****************************************************************************/
 #endif	/* mcfuart_h */

drivers/serial/mcf.c

@@ -263,6 +263,7 @@ static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
 	}
 
 	spin_lock_irqsave(&port->lock, flags);
+	uart_update_timeout(port, termios->c_cflag, baud);
 	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
 	writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
 	writeb(MCFUART_UCR_CMDRESETMRPTR, port->membase + MCFUART_UCR);
@@ -379,6 +380,7 @@ static irqreturn_t mcf_interrupt(int irq, void *data)
 static void mcf_config_port(struct uart_port *port, int flags)
 {
 	port->type = PORT_MCF;
+	port->fifosize = MCFUART_TXFIFOSIZE;
 
 	/* Clear mask, so no surprise interrupts. */
 	writeb(0, port->membase + MCFUART_UIMR);
@@ -424,7 +426,7 @@ static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
 /*
  *	Define the basic serial functions we support.
  */
-static struct uart_ops mcf_uart_ops = {
+static const struct uart_ops mcf_uart_ops = {
 	.tx_empty	= mcf_tx_empty,
 	.get_mctrl	= mcf_get_mctrl,
 	.set_mctrl	= mcf_set_mctrl,