serial: sh-sci: Allow for compressed SCIF address

This change “serial: sh-sci: Allow for compressed SCIF address” in Linux kernel is authored by Chris Brandt <chris.brandt [at] renesas.com> on Tue Jul 31 05:41:37 2018 -0500.

serial: sh-sci: Allow for compressed SCIF address

Some devices with SCIx_SH4_SCIF_REGTYPE have no space between registers.
Use the register area size to determine the spacing between register.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This Linux change may have been applied to various maintained Linux releases and you can find Linux releases including commit 2d4dd0d.

There are 25 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 drivers/tty/serial/sh-sci.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 6ff6f2b..c29244f 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -348,15 +348,15 @@ struct sci_port {
 	[SCIx_SH4_SCIF_REGTYPE] = {
 		.regs = {
 			[SCSMR]		= { 0x00, 16 },
-			[SCBRR]		= { 0x04,  8 },
-			[SCSCR]		= { 0x08, 16 },
-			[SCxTDR]	= { 0x0c,  8 },
-			[SCxSR]		= { 0x10, 16 },
-			[SCxRDR]	= { 0x14,  8 },
-			[SCFCR]		= { 0x18, 16 },
-			[SCFDR]		= { 0x1c, 16 },
-			[SCSPTR]	= { 0x20, 16 },
-			[SCLSR]		= { 0x24, 16 },
+			[SCBRR]		= { 0x02,  8 },
+			[SCSCR]		= { 0x04, 16 },
+			[SCxTDR]	= { 0x06,  8 },
+			[SCxSR]		= { 0x08, 16 },
+			[SCxRDR]	= { 0x0a,  8 },
+			[SCFCR]		= { 0x0c, 16 },
+			[SCFDR]		= { 0x0e, 16 },
+			[SCSPTR]	= { 0x10, 16 },
+			[SCLSR]		= { 0x12, 16 },
 		},
 		.fifosize = 16,
 		.overrun_reg = SCLSR,
@@ -2848,7 +2848,7 @@ static int sci_init_single(struct platform_device *dev,
 {
 	struct uart_port *port = &sci_port->port;
 	const struct resource *res;
-	unsigned int i;
+	unsigned int i, regtype;
 	int ret;
 
 	sci_port->cfg	= p;
@@ -2885,6 +2885,7 @@ static int sci_init_single(struct platform_device *dev,
 	if (unlikely(sci_port->params == NULL))
 		return -EINVAL;
 
+	regtype = sci_port->params - sci_port_params;
 	switch (p->type) {
 	case PORT_SCIFB:
 		sci_port->rx_trigger = 48;
@@ -2939,6 +2940,10 @@ static int sci_init_single(struct platform_device *dev,
 			port->regshift = 1;
 	}
 
+	if (regtype == SCIx_SH4_SCIF_REGTYPE)
+		if (sci_port->reg_size >= 0x20)
+			port->regshift = 1;
+
 	/*
 	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
 	 * for the multi-IRQ ports, which is where we are primarily

The commit for this change in Linux stable tree is 2d4dd0d (patch).

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