@@ -17,6 +17,8 @@ Optional properties:
   function pin for the USART RTS feature. If unsure, don't specify this property.
 - cts-gpios: specify a GPIO for CTS line. It will use specified PIO instead of the peripheral
   function pin for the USART CTS feature. If unsure, don't specify this property.
+- dtr-gpios: specify a GPIO for DTR line. It will use specified PIO instead of the peripheral
+  function pin for the USART DTR feature. If unsure, don't specify this property.
 - add dma bindings for dma transfer:
 	- dmas: DMA specifier, consisting of a phandle to DMA controller node,
 		memory peripheral interface and USART DMA channel ID, FIFO configuration.

@@ -39,6 +41,7 @@ Example:
 		atmel,use-dma-tx;
 		rts-gpios = <&pioD 15 0>;
 		cts-gpios = <&pioD 16 0>;
+		dtr-gpios = <&pioD 17 0>;
 	};
 
 - use DMA:

@@ -924,6 +924,7 @@ static struct atmel_uart_data dbgu_data = {
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -964,6 +965,7 @@ static struct atmel_uart_data uart0_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -1016,6 +1018,7 @@ static struct atmel_uart_data uart1_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1069,6 +1072,7 @@ static struct atmel_uart_data uart2_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1114,6 +1118,7 @@ static struct atmel_uart_data uart3_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);

@@ -821,6 +821,7 @@ static struct atmel_uart_data dbgu_data = {
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -861,6 +862,7 @@ static struct atmel_uart_data uart0_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -914,6 +916,7 @@ static struct atmel_uart_data uart1_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -959,6 +962,7 @@ static struct atmel_uart_data uart2_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1004,6 +1008,7 @@ static struct atmel_uart_data uart3_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);

@@ -1049,6 +1054,7 @@ static struct atmel_uart_data uart4_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart4_dmamask = DMA_BIT_MASK(32);

@@ -1089,6 +1095,7 @@ static struct atmel_uart_data uart5_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart5_dmamask = DMA_BIT_MASK(32);

@@ -882,6 +882,7 @@ static struct atmel_uart_data dbgu_data = {
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -922,6 +923,7 @@ static struct atmel_uart_data uart0_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -967,6 +969,7 @@ static struct atmel_uart_data uart1_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1012,6 +1015,7 @@ static struct atmel_uart_data uart2_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1326,6 +1326,7 @@ static struct atmel_uart_data dbgu_data = {
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -1366,6 +1367,7 @@ static struct atmel_uart_data uart0_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -1411,6 +1413,7 @@ static struct atmel_uart_data uart1_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1456,6 +1459,7 @@ static struct atmel_uart_data uart2_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1589,6 +1589,7 @@ static struct atmel_uart_data dbgu_data = {
 	.use_dma_rx	= 0,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -1629,6 +1630,7 @@ static struct atmel_uart_data uart0_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -1674,6 +1676,7 @@ static struct atmel_uart_data uart1_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1719,6 +1722,7 @@ static struct atmel_uart_data uart2_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1764,6 +1768,7 @@ static struct atmel_uart_data uart3_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);

@@ -958,6 +958,7 @@ static struct atmel_uart_data dbgu_data = {
 	.use_dma_rx	= 0,		/* DBGU not capable of receive DMA */
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);

@@ -998,6 +999,7 @@ static struct atmel_uart_data uart0_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);

@@ -1051,6 +1053,7 @@ static struct atmel_uart_data uart1_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);

@@ -1096,6 +1099,7 @@ static struct atmel_uart_data uart2_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);

@@ -1141,6 +1145,7 @@ static struct atmel_uart_data uart3_data = {
 	.use_dma_rx	= 1,
 	.rts_gpio	= -EINVAL,
 	.cts_gpio	= -EINVAL,
+	.dtr_gpio	= -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);

@@ -133,6 +133,7 @@ struct gpio_lines {
 	int rts;	/* optional RTS GPIO */
 	int cts;	/* optional CTS GPIO */
 	int cts_irq;
+	int dtr;	/* optional DTR GPIO */
 };
 
 /*

@@ -339,6 +340,13 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
 	else
 		control |= ATMEL_US_RTSDIS;
 
+	if (gpio_is_valid(atmel_port->gpio.dtr)) {
+		if (mctrl & TIOCM_DTR)
+			gpio_set_value(atmel_port->gpio.dtr, 0);
+		else
+			gpio_set_value(atmel_port->gpio.dtr, 1);
+	}
+
 	if (mctrl & TIOCM_DTR)
 		control |= ATMEL_US_DTREN;
 	else

@@ -2454,6 +2462,8 @@ static int atmel_init_gpios(struct atmel_uart_port *atmel_port,
 				 "RTS", NULL);
 	ret += atmel_request_gpio(&pdev->dev, atmel_port->gpio.cts,
 				  "CTS", &atmel_port->gpio.cts_irq);
+	ret += atmel_request_gpio(&pdev->dev, atmel_port->gpio.dtr,
+				  "DTR", NULL);
 	return ret;
 }
 

@@ -2494,13 +2504,16 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	port->uart.line = ret;
 	port->gpio.rts = -EINVAL; /* Invalid, zero could be valid */
 	port->gpio.cts = -EINVAL;
+	port->gpio.dtr = -EINVAL;
 	port->gpio.cts_irq = INVALID_IRQ;
 	if (pdata) {
 		port->gpio.rts = pdata->rts_gpio;
 		port->gpio.cts = pdata->cts_gpio;
+		port->gpio.dtr = pdata->dtr_gpio;
 	} else if (np) {
 		port->gpio.rts = of_get_named_gpio(np, "rts-gpios", 0);
 		port->gpio.cts = of_get_named_gpio(np, "cts-gpios", 0);
+		port->gpio.dtr = of_get_named_gpio(np, "dtr-gpios", 0);
 	}
 
 	ret = atmel_init_gpios(port, pdev);

@@ -86,6 +86,7 @@ struct atmel_uart_data {
 	struct serial_rs485	rs485;		/* rs485 settings */
 	int			rts_gpio;	/* optional RTS GPIO */
 	int			cts_gpio;	/* optional CTS GPIO */
+	int			dtr_gpio;	/* optional DTR GPIO */
 };
 
  /* Touchscreen Controller */