On sam9x5, dedicated CTS (and RTS) pins are unusable together with the
LCDC, the EMAC, or the MMC because they share the same line.
Moreover, the USART controller doesn't handle DTR/DSR/DCD/RI signals,
so we have to control them via GPIO.
This patch permits to use GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI
signals.
Signed-off-by: Richard Genoud <richard.genoud@xxxxxxxxx>
---
.../devicetree/bindings/serial/atmel-usart.txt | 12 ++-
arch/arm/mach-at91/at91rm9200_devices.c | 16 ++--
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/Kconfig | 1 +
drivers/tty/serial/atmel_serial.c | 105 ++++++++++++++-------
include/linux/platform_data/atmel.h | 1 -
10 files changed, 90 insertions(+), 70 deletions(-)
diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt
index 17c1042b2df8..a6391e70a8fd 100644
--- a/Documentation/devicetree/bindings/serial/atmel-usart.txt
+++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt
@@ -13,8 +13,9 @@ 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.
+- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively.
+ It will use specified PIO instead of the peripheral function pin for the USART 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.
@@ -35,7 +36,12 @@ Example:
clock-names = "usart";
atmel,use-dma-rx;
atmel,use-dma-tx;
- rts-gpios = <&pioD 15 0>;
+ rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>;
+ cts-gpios = <&pioD 16 GPIO_ACTIVE_LOW>;
+ dtr-gpios = <&pioD 17 GPIO_ACTIVE_LOW>;
+ dsr-gpios = <&pioD 18 GPIO_ACTIVE_LOW>;
+ dcd-gpios = <&pioD 20 GPIO_ACTIVE_LOW>;
+ rng-gpios = <&pioD 19 GPIO_ACTIVE_LOW>;
};
- use DMA:
diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c
index f3f19f21352a..291a90a5b1d4 100644
--- a/arch/arm/mach-at91/at91rm9200_devices.c
+++ b/arch/arm/mach-at91/at91rm9200_devices.c
@@ -15,6 +15,7 @@
#include <linux/dma-mapping.h>
#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/i2c-gpio.h>
@@ -923,7 +924,6 @@ 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);
@@ -962,7 +962,14 @@ static struct resource uart0_resources[] = {
static struct atmel_uart_data uart0_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
- .rts_gpio = -EINVAL,
+};
+
+static struct gpiod_lookup_table uart0_gpios_table = {
+ .dev_id = "atmel_usart",
+ .table = {
+ GPIO_LOOKUP("pioA", 21, "rts", GPIO_ACTIVE_LOW),
+ { },
+ },
};
static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -993,7 +1000,7 @@ static inline void configure_usart0_pins(unsigned pins)
* We need to drive the pin manually. The serial driver will driver
* this to high when initializing.
*/
- uart0_data.rts_gpio = AT91_PIN_PA21;
+ gpiod_add_lookup_table(&uart0_gpios_table);
}
}
@@ -1013,7 +1020,6 @@ 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);
@@ -1065,7 +1071,6 @@ 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);
@@ -1109,7 +1114,6 @@ 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 2ae7715f1309..a1b989eac8b8 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -820,7 +820,6 @@ 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);
@@ -859,7 +858,6 @@ 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);
@@ -911,7 +909,6 @@ 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);
@@ -955,7 +952,6 @@ 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);
@@ -999,7 +995,6 @@ 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);
@@ -1043,7 +1038,6 @@ 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);
@@ -1082,7 +1076,6 @@ 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 80e35895d28f..b5f7a7226ff8 100644
--- a/arch/arm/mach-at91/at91sam9261_devices.c
+++ b/arch/arm/mach-at91/at91sam9261_devices.c
@@ -881,7 +881,6 @@ 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);
@@ -920,7 +919,6 @@ 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);
@@ -964,7 +962,6 @@ 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);
@@ -1008,7 +1005,6 @@ 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 43d53d6156dd..39803c3296b2 100644
--- a/arch/arm/mach-at91/at91sam9263_devices.c
+++ b/arch/arm/mach-at91/at91sam9263_devices.c
@@ -1325,7 +1325,6 @@ 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);
@@ -1364,7 +1363,6 @@ 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);
@@ -1408,7 +1406,6 @@ 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);
@@ -1452,7 +1449,6 @@ 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 77b04c2edd78..4e53d8d9737b 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -1588,7 +1588,6 @@ 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);
@@ -1627,7 +1626,6 @@ 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);
@@ -1671,7 +1669,6 @@ 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);
@@ -1715,7 +1712,6 @@ 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);
@@ -1759,7 +1755,6 @@ 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 428fc412aaf1..f75985062913 100644
--- a/arch/arm/mach-at91/at91sam9rl_devices.c
+++ b/arch/arm/mach-at91/at91sam9rl_devices.c
@@ -957,7 +957,6 @@ 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);
@@ -996,7 +995,6 @@ 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);
@@ -1048,7 +1046,6 @@ 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);
@@ -1092,7 +1089,6 @@ 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);
@@ -1136,7 +1132,6 @@ 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/Kconfig b/drivers/tty/serial/Kconfig
index 7e8f15cfb8d0..f4e20410a138 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -97,6 +97,7 @@ config SERIAL_ATMEL
bool "AT91 / AT32 on-chip serial port support"
depends on ARCH_AT91 || AVR32
select SERIAL_CORE
+ select SERIAL_MCTRL_GPIO
help
This enables the driver for the on-chip UARTs of the Atmel
AT91 and AT32 processors.
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 53eeea13ff16..43ca659c1d4b 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -43,6 +43,8 @@
#include <linux/platform_data/atmel.h>
#include <linux/timer.h>
#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/err.h>
#include <asm/io.h>
#include <asm/ioctls.h>
@@ -57,6 +59,8 @@
#include <linux/serial_core.h>
+#include "serial_mctrl_gpio.h"
+
static void atmel_start_rx(struct uart_port *port);
static void atmel_stop_rx(struct uart_port *port);
@@ -162,7 +166,7 @@ struct atmel_uart_port {
struct circ_buf rx_ring;
struct serial_rs485 rs485; /* rs485 settings */
- int rts_gpio; /* optional RTS GPIO */
+ struct mctrl_gpios *gpios;
unsigned int tx_done_mask;
bool is_usart; /* usart or uart */
struct timer_list uart_timer; /* uart timer */
@@ -237,6 +241,50 @@ static bool atmel_use_dma_rx(struct uart_port *port)
return atmel_port->use_dma_rx;
}
+static unsigned int atmel_get_lines_status(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ unsigned int status, ret = 0;
+
+ status = UART_GET_CSR(port);
+
+ mctrl_gpio_get(atmel_port->gpios, &ret);
+
+ if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
+ UART_GPIO_CTS))) {
+ if (ret & TIOCM_CTS)
+ status &= ~ATMEL_US_CTS;
+ else
+ status |= ATMEL_US_CTS;
+ }
+
+ if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
+ UART_GPIO_DSR))) {
+ if (ret & TIOCM_DSR)
+ status &= ~ATMEL_US_DSR;
+ else
+ status |= ATMEL_US_DSR;
+ }
+
+ if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
+ UART_GPIO_RI))) {
+ if (ret & TIOCM_RI)
+ status &= ~ATMEL_US_RI;
+ else
+ status |= ATMEL_US_RI;
+ }
+
+ if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
+ UART_GPIO_DCD))) {
+ if (ret & TIOCM_CD)
+ status &= ~ATMEL_US_DCD;
+ else
+ status |= ATMEL_US_DCD;
+ }
+
+ return status;
+}
+
/* Enable or disable the rs485 support */
void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
{
@@ -296,17 +344,6 @@ 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);
- /*
- * 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);
- }
-
if (mctrl & TIOCM_RTS)
control |= ATMEL_US_RTSEN;
else
@@ -319,6 +356,8 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
UART_PUT_CR(port, control);
+ mctrl_gpio_set(atmel_port->gpios, mctrl);
+
/* Local loopback mode? */
mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
if (mctrl & TIOCM_LOOP)
@@ -346,7 +385,8 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
*/
static u_int atmel_get_mctrl(struct uart_port *port)
{
- unsigned int status, ret = 0;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ unsigned int ret = 0, status;
status = UART_GET_CSR(port);
@@ -362,7 +402,7 @@ static u_int atmel_get_mctrl(struct uart_port *port)
if (!(status & ATMEL_US_RI))
ret |= TIOCM_RI;
- return ret;
+ return mctrl_gpio_get(atmel_port->gpios, &ret);
}
/*
@@ -1042,7 +1082,7 @@ static irqreturn_t atmel_interrupt(int irq, void *dev_id)
unsigned int status, pending, pass_counter = 0;
do {
- status = UART_GET_CSR(port);
+ status = atmel_get_lines_status(port);
pending = status & UART_GET_IMR(port);
if (!pending)
break;
@@ -1568,7 +1608,7 @@ static int atmel_startup(struct uart_port *port)
}
/* Save current CSR for comparison in atmel_tasklet_func() */
- atmel_port->irq_status_prev = UART_GET_CSR(port);
+ atmel_port->irq_status_prev = atmel_get_lines_status(port);
atmel_port->irq_status = atmel_port->irq_status_prev;
/*
@@ -2324,6 +2364,15 @@ static int atmel_serial_resume(struct platform_device *pdev)
#define atmel_serial_resume NULL
#endif
+static int atmel_init_gpios(struct atmel_uart_port *p, struct device *dev)
+{
+ p->gpios = mctrl_gpio_init(dev, 0);
+ if (IS_ERR_OR_NULL(p->gpios))
+ return -1;
+
+ return 0;
+}
+
static int atmel_serial_probe(struct platform_device *pdev)
{
struct atmel_uart_port *port;
@@ -2359,25 +2408,11 @@ 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_gpios(port, &pdev->dev);
+ if (ret < 0)
+ dev_err(&pdev->dev, "%s",
+ "Failed to initialize GPIOs. The serial port may not work as expected");
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 e26b0c14edea..cea9f70133c5 100644
--- a/include/linux/platform_data/atmel.h
+++ b/include/linux/platform_data/atmel.h
@@ -84,7 +84,6 @@ 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 */
--
1.8.5.5
--
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