[PATCHv2 1/3] serial: xilinx_uartps: Let get_mctrl return status

[PATCHv2 1/3] serial: xilinx_uartps: Let get_mctrl return status

[shubhrajyoti.datta]

From: Maarten Brock <m.brock@vanmierlo.com>

Some of the applications like microcom do not work if
modem is disabled. To fix them we always return
TIOCM_CTS | TIOCM_DSR | TIOCM_CAR instead of 0 when
using cts_override. Make get_mctrl return actual status
when not using cts_override.

Signed-off-by: Maarten Brock <m.brock@vanmierlo.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
 drivers/tty/serial/xilinx_uartps.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 4e55bc3..acdb4fa5 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -158,6 +158,16 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
 #define CDNS_UART_MODEMCR_DTR	0x00000001 /* Data Terminal Ready */
 
 /*
+ * Modem Status register:
+ * The read/write Modem Status register reports the interface with the modem
+ * or data set, or a peripheral device emulating a modem.
+ */
+#define CDNS_UART_MODEMSR_DCD	BIT(7) /* Data Carrier Detect */
+#define CDNS_UART_MODEMSR_RI	BIT(6) /* Ting Indicator */
+#define CDNS_UART_MODEMSR_DSR	BIT(5) /* Data Set Ready */
+#define CDNS_UART_MODEMSR_CTS	BIT(4) /* Clear To Send */
+
+/*
  * Channel Status Register:
  * The channel status register (CSR) is provided to enable the control logic
  * to monitor the status of bits in the channel interrupt status register,
@@ -1007,12 +1017,24 @@ static void cdns_uart_config_port(struct uart_port *port, int flags)
  */
 static unsigned int cdns_uart_get_mctrl(struct uart_port *port)
 {
+	u32 val;
+	unsigned int mctrl = 0;
 	struct cdns_uart *cdns_uart_data = port->private_data;
 
 	if (cdns_uart_data->cts_override)
-		return 0;
-
-	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+	val = readl(port->membase + CDNS_UART_MODEMSR);
+	if (val & CDNS_UART_MODEMSR_CTS)
+		mctrl |= TIOCM_CTS;
+	if (val & CDNS_UART_MODEMSR_DSR)
+		mctrl |= TIOCM_DSR;
+	if (val & CDNS_UART_MODEMSR_RI)
+		mctrl |= TIOCM_RNG;
+	if (val & CDNS_UART_MODEMSR_DCD)
+		mctrl |= TIOCM_CAR;
+
+	return mctrl;
 }
 
 static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
-- 
2.1.1

[PATCHv2 2/3] serial: xilinx_uartps: set_termios sets flowcontrol

[shubhrajyoti.datta]

From: Maarten Brock <m.brock@vanmierlo.com>

Let set_termios enable/disable automatic flow control.
set_mctrl should not touch automatic flow control.

Signed-off-by: Maarten Brock <m.brock@vanmierlo.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
 drivers/tty/serial/xilinx_uartps.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index acdb4fa5..e82f8db 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -694,7 +694,7 @@ static void cdns_uart_break_ctl(struct uart_port *port, int ctl)
 static void cdns_uart_set_termios(struct uart_port *port,
 				struct ktermios *termios, struct ktermios *old)
 {
-	unsigned int cval = 0;
+	u32 cval = 0;
 	unsigned int baud, minbaud, maxbaud;
 	unsigned long flags;
 	unsigned int ctrl_reg, mode_reg, val;
@@ -815,6 +815,13 @@ static void cdns_uart_set_termios(struct uart_port *port,
 	cval |= mode_reg & 1;
 	writel(cval, port->membase + CDNS_UART_MR);
 
+	cval = readl(port->membase + CDNS_UART_MODEMCR);
+	if (termios->c_cflag & CRTSCTS)
+		cval |= CDNS_UART_MODEMCR_FCM;
+	else
+		cval &= ~CDNS_UART_MODEMCR_FCM;
+	writel(cval, port->membase + CDNS_UART_MODEMCR);
+
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
@@ -1049,12 +1056,9 @@ static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 	val = readl(port->membase + CDNS_UART_MODEMCR);
 	mode_reg = readl(port->membase + CDNS_UART_MR);
 
-	val &= ~(CDNS_UART_MODEMCR_RTS | CDNS_UART_MODEMCR_DTR |
-		 CDNS_UART_MODEMCR_FCM);
+	val &= ~(CDNS_UART_MODEMCR_RTS | CDNS_UART_MODEMCR_DTR);
 	mode_reg &= ~CDNS_UART_MR_CHMODE_MASK;
 
-	if (mctrl & TIOCM_RTS || mctrl & TIOCM_DTR)
-		val |= CDNS_UART_MODEMCR_FCM;
 	if (mctrl & TIOCM_LOOP)
 		mode_reg |= CDNS_UART_MR_CHMODE_L_LOOP;
 	else
-- 
2.1.1

[PATCHv2 3/3] serial: xilinx_uartps: set_mctrl sets RTS and DTR

[shubhrajyoti.datta]

From: Maarten Brock <m.brock@vanmierlo.com>

set_mctrl now sets RTS and DTR.

Signed-off-by: Maarten Brock <m.brock@vanmierlo.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
 drivers/tty/serial/xilinx_uartps.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index e82f8db..b4fd550 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1059,6 +1059,10 @@ static void cdns_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 	val &= ~(CDNS_UART_MODEMCR_RTS | CDNS_UART_MODEMCR_DTR);
 	mode_reg &= ~CDNS_UART_MR_CHMODE_MASK;
 
+	if (mctrl & TIOCM_RTS)
+		val |= CDNS_UART_MODEMCR_RTS;
+	if (mctrl & TIOCM_DTR)
+		val |= CDNS_UART_MODEMCR_DTR;
 	if (mctrl & TIOCM_LOOP)
 		mode_reg |= CDNS_UART_MR_CHMODE_L_LOOP;
 	else
-- 
2.1.1