[PATCH v2] serial: sh-sci: byte allocated register support

[Yoshinori Sato <ysato@users.sourceforge.jp>]

H8/300 SCI registers allocated byte address.
It must support to the case where shift count is 0.

Changes v2.
more simply code.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
---
 drivers/tty/serial/sh-sci.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index c181eb37f985..3c7326e11d37 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -2863,10 +2863,12 @@ static int sci_init_single(struct platform_device *dev,
 	port->fifosize		= sci_port->params->fifosize;
 
 	if (port->type = PORT_SCI) {
-		if (sci_port->reg_size >= 0x20)
-			port->regshift = 2;
-		else
-			port->regshift = 1;
+		/*
+		 * reg_size < 0x10: BYTE aligned (scale factor=1).
+		 * reg_size >= 0x10 and < 0x20: WORD aligned (scale factor=2).
+		 * reg_size >= 0x20: DWORD aligned (scale factor=4).
+		 */
+		port->regshift = sci_port->reg_size >> 4;
 	}
 
 	/*
-- 
2.11.0