[PATCH] serial: clps711x: Use mctrl_gpio helpers for handling modem signals

[Alexander Shiyan <shc_work@mail.ru>]

This patch permits to use GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI
signals.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
---
 .../bindings/serial/cirrus,clps711x-uart.txt       |  7 +++--
 drivers/tty/serial/Kconfig                         |  1 +
 drivers/tty/serial/clps711x.c                      | 32 +++++++---------------
 3 files changed, 16 insertions(+), 24 deletions(-)

diff --git a/Documentation/devicetree/bindings/serial/cirrus,clps711x-uart.txt b/Documentation/devicetree/bindings/serial/cirrus,clps711x-uart.txt
index 12f3cf8..caaeb25 100644
--- a/Documentation/devicetree/bindings/serial/cirrus,clps711x-uart.txt
+++ b/Documentation/devicetree/bindings/serial/cirrus,clps711x-uart.txt
@@ -8,7 +8,8 @@ Required properties:
 - syscon: Phandle to SYSCON node, which contain UART control bits.
 
 Optional properties:
-- uart-use-ms: Indicate the UART has modem signal (DCD, DSR, CTS).
+- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD
+  line respectively.
 
 Note: Each UART port should have an alias correctly numbered
 in "aliases" node.
@@ -24,5 +25,7 @@ Example:
 		interrupts = <12 13>;
 		clocks = <&clks 11>;
 		syscon = <&syscon1>;
-		uart-use-ms;
+		cts-gpios = <&sysgpio 0 GPIO_ACTIVE_LOW>;
+		dsr-gpios = <&sysgpio 1 GPIO_ACTIVE_LOW>;
+		dcd-gpios = <&sysgpio 2 GPIO_ACTIVE_LOW>;
 	};
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 26cec64..75cc59f 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -204,6 +204,7 @@ config SERIAL_CLPS711X
 	tristate "CLPS711X serial port support"
 	depends on ARCH_CLPS711X || COMPILE_TEST
 	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO
 	help
 	  This enables the driver for the on-chip UARTs of the Cirrus
 	  Logic EP711x/EP721x/EP731x processors.
diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c
index f5b4c3d..acfe317 100644
--- a/drivers/tty/serial/clps711x.c
+++ b/drivers/tty/serial/clps711x.c
@@ -33,6 +33,8 @@
 #include <linux/mfd/syscon.h>
 #include <linux/mfd/syscon/clps711x.h>
 
+#include "serial_mctrl_gpio.h"
+
 #define UART_CLPS711X_DEVNAME	"ttyCL"
 #define UART_CLPS711X_NR	2
 #define UART_CLPS711X_MAJOR	204
@@ -62,7 +64,7 @@ struct clps711x_port {
 	unsigned int		tx_enabled;
 	int			rx_irq;
 	struct regmap		*syscon;
-	bool			use_ms;
+	struct mctrl_gpios	*gpios;
 };
 
 static struct uart_driver clps711x_uart = {
@@ -198,28 +200,17 @@ static unsigned int uart_clps711x_tx_empty(struct uart_port *port)
 
 static unsigned int uart_clps711x_get_mctrl(struct uart_port *port)
 {
+	unsigned int result = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
 	struct clps711x_port *s = dev_get_drvdata(port->dev);
-	unsigned int result = 0;
-
-	if (s->use_ms) {
-		u32 sysflg = 0;
-
-		regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
-		if (sysflg & SYSFLG1_DCD)
-			result |= TIOCM_CAR;
-		if (sysflg & SYSFLG1_DSR)
-			result |= TIOCM_DSR;
-		if (sysflg & SYSFLG1_CTS)
-			result |= TIOCM_CTS;
-	} else
-		result = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
 
-	return result;
+	return mctrl_gpio_get(s->gpios, &result);
 }
 
 static void uart_clps711x_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-	/* Do nothing */
+	struct clps711x_port *s = dev_get_drvdata(port->dev);
+
+	mctrl_gpio_set(s->gpios, mctrl);
 }
 
 static void uart_clps711x_break_ctl(struct uart_port *port, int break_state)
@@ -490,15 +481,10 @@ static int uart_clps711x_probe(struct platform_device *pdev)
 		s->syscon = syscon_regmap_lookup_by_pdevname(syscon_name);
 		if (IS_ERR(s->syscon))
 			return PTR_ERR(s->syscon);
-
-		s->use_ms = !index;
 	} else {
 		s->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
 		if (IS_ERR(s->syscon))
 			return PTR_ERR(s->syscon);
-
-		if (!index)
-			s->use_ms = of_property_read_bool(np, "uart-use-ms");
 	}
 
 	s->port.line		= index;
@@ -513,6 +499,8 @@ static int uart_clps711x_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, s);
 
+	s->gpios = mctrl_gpio_init(&pdev->dev, 0);
+
 	ret = uart_add_one_port(&clps711x_uart, &s->port);
 	if (ret)
 		return ret;
-- 
1.8.5.5