serial: 8250_omap: refactor mdr1 update

The silicon errata[1] workaround implemented in a follow-on
patch, "serial: 8250_omap: workaround errata on disabling
UART after using DMA", requires MDR1 register programming.

Extract MDR1 register update into helper function,
omap8250_update_mdr1() to help with that.

[1] Advisory 21 in http://www.ti.com/lit/er/sprz408b/sprz408b.pdfSigned-off-by: NSekhar Nori <nsekhar@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_omap.c

@@ -232,6 +232,15 @@ static void omap8250_update_scr(struct uart_8250_port *up,
 	serial_out(up, UART_OMAP_SCR, priv->scr);
 }
 
+static void omap8250_update_mdr1(struct uart_8250_port *up,
+				 struct omap8250_priv *priv)
+{
+	if (priv->habit & UART_ERRATA_i202_MDR1_ACCESS)
+		omap_8250_mdr1_errataset(up, priv);
+	else
+		serial_out(up, UART_OMAP_MDR1, priv->mdr1);
+}
+
 static void omap8250_restore_regs(struct uart_8250_port *up)
 {
 	struct omap8250_priv *priv = up->port.private_data;
@@ -282,11 +291,9 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
 	serial_out(up, UART_XOFF1, priv->xoff);
 
 	serial_out(up, UART_LCR, up->lcr);
-	/* need mode A for FCR */
-	if (priv->habit & UART_ERRATA_i202_MDR1_ACCESS)
-		omap_8250_mdr1_errataset(up, priv);
-	else
-		serial_out(up, UART_OMAP_MDR1, priv->mdr1);
+
+	omap8250_update_mdr1(up, priv);
+
 	up->port.ops->set_mctrl(&up->port, up->port.mctrl);
 }