[PATCH 2/2] sc16is7xx: add reading CTS

[Pascal JEAN]

Hi Greg,

Here are changelog for this patch.
Best Regards

Changelog:

sc16is7xx: add reading CTS

        This patch adds the possibility to read the actual
        status of the CTS input when RTS/CTS handshaking is
        not activated (for general purposes).


Signed-off-by: Pascal JEAN <epsilo...@gmail.com>
---
 drivers/tty/serial/sc16is7xx.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 3e65079..8833a18 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -818,10 +818,19 @@ static unsigned int sc16is7xx_tx_empty(struct
uart_port *port)

 static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
 {
-       /* DCD and DSR are not wired and CTS/RTS is handled automatically
-        * so just indicate all inputs asserted
-        */
-       return TIOCM_DSR | TIOCM_CAR | TIOCM_RI | TIOCM_CTS;
+       /* DCD, DSR and RI are not wired so just indicate asserted */
+       unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_RI;
+
+       if (port->status & UPSTAT_CTS_ENABLE)
+               /* CTS handled automatically, indicates that it is always
+                * asserted, this is required for proper management of
+                * the upper layer
+                */
+               mctrl |= TIOCM_CTS;
+       else {
+               /* CTS is not managed automatically, returns its actual state
+                * the upper layer
+                */
+               u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
+
+               mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
+       }
+       return mctrl;
 }

 static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
-- 
2.7.4