From bf020fdfbbf362bed0aab90edf457fc6cffc9e46 Mon Sep 17 00:00:00 2001
From: Fabio Estevam <fabio.estevam@freescale.com>
Date: Wed, 26 Mar 2014 12:43:58 -0300
Subject: [PATCH] serial: mxs-auart: Add support for inverted RTS/CTS output

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt | 1 +
 drivers/tty/serial/mxs-auart.c                             | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt b/Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt
index 59a40f1..2351f55 100644
--- a/Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt
+++ b/Documentation/devicetree/bindings/serial/fsl-mxs-auart.txt
@@ -13,6 +13,7 @@ Required properties:
 Optional properties:
 - fsl,uart-has-rtscts : Indicate the UART has RTS and CTS lines,
 	it also means you enable the DMA support for this UART.
+- fsl,invert-rtscts: Indicate that RTS output is inverted before transmitted

 Example:
 auart0: serial@8006a000 {
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index aa97fd8..6cdcf7e 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -79,6 +79,8 @@

 #define AUART_CTRL1_XFER_COUNT(v)		((v) & 0xffff)

+#define AUART_CTRL2_INVERT_RTS			(1 << 31)
+#define AUART_CTRL2_INVERT_CTS			(1 << 30)
 #define AUART_CTRL2_DMAONERR			(1 << 26)
 #define AUART_CTRL2_TXDMAE			(1 << 25)
 #define AUART_CTRL2_RXDMAE			(1 << 24)
@@ -138,6 +140,7 @@ struct mxs_auart_port {
 #define MXS_AUART_DMA_TX_SYNC	2  /* bit 2 */
 #define MXS_AUART_DMA_RX_READY	3  /* bit 3 */
 #define MXS_AUART_RTSCTS	4  /* bit 4 */
+#define MXS_AUART_INVERT_RTSCTS	5  /* bit 5 */
 	unsigned long flags;
 	unsigned int ctrl;
 	enum mxs_auart_type devtype;
@@ -637,6 +640,8 @@ static void mxs_auart_settermios(struct uart_port *u,

 	/* figure out the hardware flow control settings */
 	if (cflag & CRTSCTS) {
+		if (test_bit(MXS_AUART_INVERT_RTSCTS, &s->flags))
+			ctrl2 |= AUART_CTRL2_INVERT_RTS | AUART_CTRL2_INVERT_CTS;
 		/*
 		 * The DMA has a bug(see errata:2836) in mx23.
 		 * So we can not implement the DMA for auart in mx23,
@@ -1023,6 +1028,9 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s,
 	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
 		set_bit(MXS_AUART_RTSCTS, &s->flags);

+	if (of_get_property(np, "fsl,invert-rtscts", NULL))
+		set_bit(MXS_AUART_INVERT_RTSCTS, &s->flags);
+
 	return 0;
 }

--
1.8.1.2