---
ChangeLog v3->v4:
- Assign RTS pin setup at runtime for the applicable
platforms. Drive it to 1 rather than 0 by default as
RTS is active low. Thanks to Jean-Christophe for noticing
the fine details... sorry for the fuzz :-/
ChangeLog v2->v3:
- Instead of disallowing GPIO 0 to be used for the RTS
signal to allow null-initialized platform data to mean
"no RTS GPIO", be more generic and actually allow it,
and patch every instance of atmel_uart_data to set
.rts_gpio to -EINVAL except for the one case where we
actually use pin 21 for RTS over GPIO.
ChangeLog v1->v2:
- Skip check for UART base address from leftover hack,
if we have an RTS GPIO we just use it.
- Set default error value on GPIO pin to -EINVAL
- Fold in a device tree support patch from Nicolas Ferre
---
.../devicetree/bindings/serial/atmel-usart.txt | 3 ++
arch/arm/mach-at91/at91rm9200_devices.c | 10 ++++-
arch/arm/mach-at91/at91sam9260_devices.c | 7 ++++
arch/arm/mach-at91/at91sam9261_devices.c | 4 ++
arch/arm/mach-at91/at91sam9263_devices.c | 4 ++
arch/arm/mach-at91/at91sam9g45_devices.c | 5 +++
arch/arm/mach-at91/at91sam9rl_devices.c | 5 +++
drivers/tty/serial/atmel_serial.c | 49
++++++++++++++--------
include/linux/platform_data/atmel.h | 1 +
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 c721e9b08066..08ac5e2ff97d 100644
--- a/arch/arm/mach-at91/at91rm9200_devices.c
+++ b/arch/arm/mach-at91/at91rm9200_devices.c
@@ -923,6 +923,7 @@ 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);
@@ -961,6 +962,7 @@ 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);
@@ -988,9 +990,10 @@ 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;
}
}
@@ -1010,6 +1013,7 @@ 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);
@@ -1061,6 +1065,7 @@ 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);
@@ -1104,6 +1109,7 @@ 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 428abfc14848..bcf4a161a3d8 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 4e02e9271ac9..d5b08ef9e848 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 3a384ef27cf6..22b13c6226cb 100644
--- a/arch/arm/mach-at91/at91sam9263_devices.c
+++ b/arch/arm/mach-at91/at91sam9263_devices.c
@@ -1325,6 +1325,7 @@ 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);
@@ -1363,6 +1364,7 @@ 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);
@@ -1406,6 +1408,7 @@ 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);
@@ -1449,6 +1452,7 @@ 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 6b8effbffc28..89f95ed711c6 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -1588,6 +1588,7 @@ 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);
@@ -1626,6 +1627,7 @@ 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);
@@ -1669,6 +1671,7 @@ 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);
@@ -1712,6 +1715,7 @@ 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);
@@ -1755,6 +1759,7 @@ 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 6cf441cadf94..3c2462b15b8b 100644
--- a/arch/arm/mach-at91/at91sam9rl_devices.c
+++ b/arch/arm/mach-at91/at91sam9rl_devices.c
@@ -957,6 +957,7 @@ 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);
@@ -995,6 +996,7 @@ 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);
@@ -1046,6 +1048,7 @@ 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);
@@ -1089,6 +1092,7 @@ 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);
@@ -1132,6 +1136,7 @@ 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 d067285a2d20..af6765d3aedb 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 */
@@ -167,6 +164,7 @@ 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 */
@@ -300,20 +298,16 @@ 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;
@@ -2365,6 +2359,25 @@ 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 */
