9 files changed, 68 insertions, 20 deletions

diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt
index 2191dcb9f1da..3adc61c2e4ca 100644
--- a/Documentation/devicetree/bindings/serial/atmel-usart.txt
+++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt
@@ -10,6 +10,8 @@ Required properties:
 Optional properties:
 - atmel,use-dma-rx: use of PDC or DMA for receiving data
 - atmel,use-dma-tx: use of PDC or DMA for transmitting data
+- rts-gpios: specify a GPIO for RTS line. It will use specified PIO instead of the peripheral
+  function pin for the USART RTS 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.
@@ -28,6 +30,7 @@ Example:
                 interrupts = <7>;
                 atmel,use-dma-rx;
                 atmel,use-dma-tx;
+                rts-gpios = <&pioD 15 0>;
         };
 
 - use DMA:
diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c
index 3ebc9792560c..605add05af7e 100644
--- a/arch/arm/mach-at91/at91rm9200_devices.c
+++ b/arch/arm/mach-at91/at91rm9200_devices.c
@@ -922,6 +922,7 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
         .use_dma_tx     = 0,
         .use_dma_rx     = 0,            /* DBGU not capable of receive DMA */
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -960,6 +961,7 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -987,9 +989,10 @@ static inline void configure_usart0_pins(unsigned pins)
         if (pins & ATMEL_UART_RTS) {
                 /*
                  * AT91RM9200 Errata #39 - RTS0 is not internally connected to PA21.
-                 *  We need to drive the pin manually.  Default is off (RTS is active low).
+                 * We need to drive the pin manually. The serial driver will driver
+                 * this to high when initializing.
                  */
-                at91_set_gpio_output(AT91_PIN_PA21, 1);
+                uart0_data.rts_gpio = AT91_PIN_PA21;
         }
 }
 
@@ -1009,6 +1012,7 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1060,6 +1064,7 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);
@@ -1103,6 +1108,7 @@ static struct resource uart3_resources[] = {
 static struct atmel_uart_data uart3_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);
diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index eda8d1679d40..b52527c78b12 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -819,6 +819,7 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
         .use_dma_tx     = 0,
         .use_dma_rx     = 0,            /* DBGU not capable of receive DMA */
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -857,6 +858,7 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -908,6 +910,7 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -951,6 +954,7 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);
@@ -994,6 +998,7 @@ static struct resource uart3_resources[] = {
 static struct atmel_uart_data uart3_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);
@@ -1037,6 +1042,7 @@ static struct resource uart4_resources[] = {
 static struct atmel_uart_data uart4_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart4_dmamask = DMA_BIT_MASK(32);
@@ -1075,6 +1081,7 @@ static struct resource uart5_resources[] = {
 static struct atmel_uart_data uart5_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart5_dmamask = DMA_BIT_MASK(32);
diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c
index b2a34740146a..6c1a2ecc306f 100644
--- a/arch/arm/mach-at91/at91sam9261_devices.c
+++ b/arch/arm/mach-at91/at91sam9261_devices.c
@@ -880,6 +880,7 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
         .use_dma_tx     = 0,
         .use_dma_rx     = 0,            /* DBGU not capable of receive DMA */
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -918,6 +919,7 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -961,6 +963,7 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1004,6 +1007,7 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);
diff --git a/arch/arm/mach-at91/at91sam9263_devices.c b/arch/arm/mach-at91/at91sam9263_devices.c
index 4aeadddbc181..97cc2a0d6f90 100644
--- a/arch/arm/mach-at91/at91sam9263_devices.c
+++ b/arch/arm/mach-at91/at91sam9263_devices.c
@@ -1324,6 +1324,7 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
         .use_dma_tx     = 0,
         .use_dma_rx     = 0,            /* DBGU not capable of receive DMA */
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -1362,6 +1363,7 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -1405,6 +1407,7 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1448,6 +1451,7 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);
diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index cb36fa872d30..c10149588e21 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -1587,6 +1587,7 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
         .use_dma_tx     = 0,
         .use_dma_rx     = 0,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -1625,6 +1626,7 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -1668,6 +1670,7 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1711,6 +1714,7 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);
@@ -1754,6 +1758,7 @@ static struct resource uart3_resources[] = {
 static struct atmel_uart_data uart3_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);
diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c
index a698bdab2cce..4120af972b61 100644
--- a/arch/arm/mach-at91/at91sam9rl_devices.c
+++ b/arch/arm/mach-at91/at91sam9rl_devices.c
@@ -956,6 +956,7 @@ static struct resource dbgu_resources[] = {
 static struct atmel_uart_data dbgu_data = {
         .use_dma_tx     = 0,
         .use_dma_rx     = 0,            /* DBGU not capable of receive DMA */
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -994,6 +995,7 @@ static struct resource uart0_resources[] = {
 static struct atmel_uart_data uart0_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -1045,6 +1047,7 @@ static struct resource uart1_resources[] = {
 static struct atmel_uart_data uart1_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1088,6 +1091,7 @@ static struct resource uart2_resources[] = {
 static struct atmel_uart_data uart2_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart2_dmamask = DMA_BIT_MASK(32);
@@ -1131,6 +1135,7 @@ static struct resource uart3_resources[] = {
 static struct atmel_uart_data uart3_data = {
         .use_dma_tx     = 1,
         .use_dma_rx     = 1,
+        .rts_gpio       = -EINVAL,
 };
 
 static u64 uart3_dmamask = DMA_BIT_MASK(32);
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index c7d99af46a96..40d6c9b0d98b 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -35,21 +35,18 @@
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <linux/dma-mapping.h>
 #include <linux/atmel_pdc.h>
 #include <linux/atmel_serial.h>
 #include <linux/uaccess.h>
 #include <linux/platform_data/atmel.h>
 #include <linux/timer.h>
+#include <linux/gpio.h>
 
 #include <asm/io.h>
 #include <asm/ioctls.h>
 
-#ifdef CONFIG_ARM
-#include <mach/cpu.h>
-#include <asm/gpio.h>
-#endif
-
 #define PDC_BUFFER_SIZE         512
 /* Revisit: We should calculate this based on the actual port settings */
 #define PDC_RX_TIMEOUT          (3 * 10)                /* 3 bytes */
@@ -168,6 +165,7 @@ struct atmel_uart_port {
         struct circ_buf         rx_ring;
 
         struct serial_rs485     rs485;          /* rs485 settings */
+        int                     rts_gpio;       /* optional RTS GPIO */
         unsigned int            tx_done_mask;
         bool                    is_usart;       /* usart or uart */
         struct timer_list       uart_timer;     /* uart timer */
@@ -301,20 +299,16 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
         unsigned int mode;
         struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 
-#ifdef CONFIG_ARCH_AT91RM9200
-        if (cpu_is_at91rm9200()) {
-                /*
-                 * AT91RM9200 Errata #39: RTS0 is not internally connected
-                 * to PA21. We need to drive the pin manually.
-                 */
-                if (port->mapbase == AT91RM9200_BASE_US0) {
-                        if (mctrl & TIOCM_RTS)
-                                at91_set_gpio_value(AT91_PIN_PA21, 0);
-                        else
-                                at91_set_gpio_value(AT91_PIN_PA21, 1);
-                }
+        /*
+         * AT91RM9200 Errata #39: RTS0 is not internally connected
+         * to PA21. We need to drive the pin as a GPIO.
+         */
+        if (gpio_is_valid(atmel_port->rts_gpio)) {
+                if (mctrl & TIOCM_RTS)
+                        gpio_set_value(atmel_port->rts_gpio, 0);
+                else
+                        gpio_set_value(atmel_port->rts_gpio, 1);
         }
-#endif
 
         if (mctrl & TIOCM_RTS)
                 control |= ATMEL_US_RTSEN;
@@ -2379,6 +2373,25 @@ static int atmel_serial_probe(struct platform_device *pdev)
         port = &atmel_ports[ret];
         port->backup_imr = 0;
         port->uart.line = ret;
+        port->rts_gpio = -EINVAL; /* Invalid, zero could be valid */
+        if (pdata)
+                port->rts_gpio = pdata->rts_gpio;
+        else if (np)
+                port->rts_gpio = of_get_named_gpio(np, "rts-gpios", 0);
+
+        if (gpio_is_valid(port->rts_gpio)) {
+                ret = devm_gpio_request(&pdev->dev, port->rts_gpio, "RTS");
+                if (ret) {
+                        dev_err(&pdev->dev, "error requesting RTS GPIO\n");
+                        goto err;
+                }
+                /* Default to 1 as RTS is active low */
+                ret = gpio_direction_output(port->rts_gpio, 1);
+                if (ret) {
+                        dev_err(&pdev->dev, "error setting up RTS GPIO\n");
+                        goto err;
+                }
+        }
 
         ret = atmel_init_port(port, pdev);
         if (ret)
diff --git a/include/linux/platform_data/atmel.h b/include/linux/platform_data/atmel.h
index cea9f70133c5..e26b0c14edea 100644
--- a/include/linux/platform_data/atmel.h
+++ b/include/linux/platform_data/atmel.h
@@ -84,6 +84,7 @@ struct atmel_uart_data {
         short                   use_dma_rx;     /* use receive DMA? */
         void __iomem            *regs;          /* virt. base address, if any */
         struct serial_rs485     rs485;          /* rs485 settings */
+        int                     rts_gpio;       /* optional RTS GPIO */
 };
 
  /* Touchscreen Controller */