On sam9x5, dedicated CTS (and RTS) pins are unusable together with the
LCDC, the EMAC, or the MMC because they share the same line.
This patch permits to use a GPIO to control the CTS line.
Signed-off-by: Richard Genoud <richard.genoud@xxxxxxxxx>
---
.../devicetree/bindings/serial/atmel-usart.txt | 3 +
arch/arm/mach-at91/at91rm9200_devices.c | 5 +
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 | 112 +++++++++++++++++++--
include/linux/platform_data/atmel.h | 1 +
9 files changed, 136 insertions(+), 10 deletions(-)
diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt
index 17c1042b2df8..6c0898e4b58e 100644
--- a/Documentation/devicetree/bindings/serial/atmel-usart.txt
+++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt
@@ -15,6 +15,8 @@ Optional properties:
- 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.
+- 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.
- 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.
@@ -36,6 +38,7 @@ Example:
atmel,use-dma-rx;
atmel,use-dma-tx;
rts-gpios = <&pioD 15 0>;
+ cts-gpios = <&pioD 16 0>;
};
- use DMA:
diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c
index 605add05af7e..4688a85cabc4 100644
--- a/arch/arm/mach-at91/at91rm9200_devices.c
+++ b/arch/arm/mach-at91/at91rm9200_devices.c
@@ -923,6 +923,7 @@ static struct atmel_uart_data dbgu_data = {
.use_dma_tx = 0,
.use_dma_rx = 0, /* DBGU not capable of receive DMA */
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -962,6 +963,7 @@ static struct atmel_uart_data uart0_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -1013,6 +1015,7 @@ static struct atmel_uart_data uart1_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1065,6 +1068,7 @@ static struct atmel_uart_data uart2_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart2_dmamask = DMA_BIT_MASK(32);
@@ -1109,6 +1113,7 @@ static struct atmel_uart_data uart3_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_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 b52527c78b12..5e8f0d1add1d 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -820,6 +820,7 @@ static struct atmel_uart_data dbgu_data = {
.use_dma_tx = 0,
.use_dma_rx = 0, /* DBGU not capable of receive DMA */
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -859,6 +860,7 @@ static struct atmel_uart_data uart0_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -911,6 +913,7 @@ static struct atmel_uart_data uart1_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -955,6 +958,7 @@ static struct atmel_uart_data uart2_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart2_dmamask = DMA_BIT_MASK(32);
@@ -999,6 +1003,7 @@ static struct atmel_uart_data uart3_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart3_dmamask = DMA_BIT_MASK(32);
@@ -1043,6 +1048,7 @@ static struct atmel_uart_data uart4_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart4_dmamask = DMA_BIT_MASK(32);
@@ -1082,6 +1088,7 @@ static struct atmel_uart_data uart5_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_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 6c1a2ecc306f..f0ccc835e331 100644
--- a/arch/arm/mach-at91/at91sam9261_devices.c
+++ b/arch/arm/mach-at91/at91sam9261_devices.c
@@ -881,6 +881,7 @@ static struct atmel_uart_data dbgu_data = {
.use_dma_tx = 0,
.use_dma_rx = 0, /* DBGU not capable of receive DMA */
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -920,6 +921,7 @@ static struct atmel_uart_data uart0_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -964,6 +966,7 @@ static struct atmel_uart_data uart1_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1008,6 +1011,7 @@ static struct atmel_uart_data uart2_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_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 97cc2a0d6f90..1e696ceacfaf 100644
--- a/arch/arm/mach-at91/at91sam9263_devices.c
+++ b/arch/arm/mach-at91/at91sam9263_devices.c
@@ -1325,6 +1325,7 @@ static struct atmel_uart_data dbgu_data = {
.use_dma_tx = 0,
.use_dma_rx = 0, /* DBGU not capable of receive DMA */
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -1364,6 +1365,7 @@ static struct atmel_uart_data uart0_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -1408,6 +1410,7 @@ static struct atmel_uart_data uart1_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1452,6 +1455,7 @@ static struct atmel_uart_data uart2_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_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 c10149588e21..b75eb826b803 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -1588,6 +1588,7 @@ static struct atmel_uart_data dbgu_data = {
.use_dma_tx = 0,
.use_dma_rx = 0,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -1627,6 +1628,7 @@ static struct atmel_uart_data uart0_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -1671,6 +1673,7 @@ static struct atmel_uart_data uart1_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1715,6 +1718,7 @@ static struct atmel_uart_data uart2_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart2_dmamask = DMA_BIT_MASK(32);
@@ -1759,6 +1763,7 @@ static struct atmel_uart_data uart3_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_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 4120af972b61..67bf5811b38f 100644
--- a/arch/arm/mach-at91/at91sam9rl_devices.c
+++ b/arch/arm/mach-at91/at91sam9rl_devices.c
@@ -957,6 +957,7 @@ static struct atmel_uart_data dbgu_data = {
.use_dma_tx = 0,
.use_dma_rx = 0, /* DBGU not capable of receive DMA */
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 dbgu_dmamask = DMA_BIT_MASK(32);
@@ -996,6 +997,7 @@ static struct atmel_uart_data uart0_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart0_dmamask = DMA_BIT_MASK(32);
@@ -1048,6 +1050,7 @@ static struct atmel_uart_data uart1_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart1_dmamask = DMA_BIT_MASK(32);
@@ -1092,6 +1095,7 @@ static struct atmel_uart_data uart2_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_gpio = -EINVAL,
};
static u64 uart2_dmamask = DMA_BIT_MASK(32);
@@ -1136,6 +1140,7 @@ static struct atmel_uart_data uart3_data = {
.use_dma_tx = 1,
.use_dma_rx = 1,
.rts_gpio = -EINVAL,
+ .cts_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 7ef99d7e070b..7a6b0506c050 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -43,6 +43,7 @@
#include <linux/platform_data/atmel.h>
#include <linux/timer.h>
#include <linux/gpio.h>
+#include <linux/irq.h>
#include <asm/io.h>
#include <asm/ioctls.h>
@@ -55,6 +56,8 @@
#define SUPPORT_SYSRQ
#endif
+#define INVALID_IRQ ((unsigned)-1)
+
#include <linux/serial_core.h>
static void atmel_start_rx(struct uart_port *port);
@@ -128,6 +131,8 @@ struct atmel_uart_char {
struct gpio_lines {
int rts; /* optional RTS GPIO */
+ int cts; /* optional CTS GPIO */
+ int cts_irq;
};
/*
@@ -168,6 +173,7 @@ struct atmel_uart_port {
struct serial_rs485 rs485; /* rs485 settings */
struct gpio_lines gpio;
unsigned int tx_done_mask;
+ bool ms_irq_enabled;
bool is_usart; /* usart or uart */
struct timer_list uart_timer; /* uart timer */
int (*prepare_rx)(struct uart_port *port);
@@ -241,6 +247,23 @@ 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 = 0;
+
+ status = UART_GET_CSR(port);
+
+ if (gpio_is_valid(atmel_port->gpio.cts)) {
+ if (gpio_get_value(atmel_port->gpio.cts))
+ status |= ATMEL_US_CTS;
+ else
+ status &= ~ATMEL_US_CTS;
+ }
+
+ return status;
+}
+
/* Enable or disable the rs485 support */
void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
{
@@ -352,7 +375,7 @@ static u_int atmel_get_mctrl(struct uart_port *port)
{
unsigned int status, ret = 0;
- status = UART_GET_CSR(port);
+ status = atmel_get_lines_status(port);
/*
* The control signals are active low.
@@ -453,8 +476,25 @@ static void atmel_stop_rx(struct uart_port *port)
*/
static void atmel_enable_ms(struct uart_port *port)
{
- UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC
- | ATMEL_US_DCDIC | ATMEL_US_CTSIC);
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ uint32_t ier;
+
+ /*
+ * Interrupt should not be enabled twice
+ */
+ if (atmel_port->ms_irq_enabled)
+ return;
+
+ atmel_port->ms_irq_enabled = true;
+
+ ier = ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC;
+
+ if (atmel_port->gpio.cts_irq != INVALID_IRQ)
+ enable_irq(atmel_port->gpio.cts_irq);
+ else
+ ier |= ATMEL_US_CTSIC;
+
+ UART_PUT_IER(port, ier);
}
/*
@@ -522,7 +562,7 @@ static void atmel_rx_chars(struct uart_port *port)
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
unsigned int status, ch;
- status = UART_GET_CSR(port);
+ status = atmel_get_lines_status(port);
while (status & ATMEL_US_RXRDY) {
ch = UART_GET_CHAR(port);
@@ -556,7 +596,7 @@ static void atmel_rx_chars(struct uart_port *port)
}
atmel_buffer_rx_char(port, status, ch);
- status = UART_GET_CSR(port);
+ status = atmel_get_lines_status(port);
}
tasklet_schedule(&atmel_port->tasklet);
@@ -1043,11 +1083,22 @@ atmel_handle_status(struct uart_port *port, unsigned int pending,
static irqreturn_t atmel_interrupt(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
unsigned int status, pending, pass_counter = 0;
+ bool gpio_handled = false;
do {
- status = UART_GET_CSR(port);
+ status = atmel_get_lines_status(port);
pending = status & UART_GET_IMR(port);
+ if (!gpio_handled) {
+ /*
+ * Dealing with GPIO interrupt
+ */
+ if ((irq != INVALID_IRQ) &&
+ (irq == atmel_port->gpio.cts_irq))
+ pending |= ATMEL_US_CTSIC;
+ gpio_handled = true;
+ }
if (!pending)
break;
@@ -1527,6 +1578,22 @@ static void atmel_get_ip_name(struct uart_port *port)
}
}
+static int atmel_request_gpio_irq(struct uart_port *port, int irq,
+ const char *name)
+{
+ int err = 0;
+
+ if (irq == INVALID_IRQ)
+ goto out;
+
+ irq_set_status_flags(irq, IRQ_NOAUTOEN);
+ err = request_irq(irq, atmel_interrupt, IRQ_TYPE_EDGE_BOTH, name, port);
+ if (err)
+ dev_err(port->dev, "atmel_startup - Can't get %s\n", name);
+out:
+ return err;
+}
+
/*
* Perform initialization and enable port for reception
*/
@@ -1543,6 +1610,7 @@ static int atmel_startup(struct uart_port *port)
* handle an unexpected interrupt
*/
UART_PUT_IDR(port, -1);
+ atmel_port->ms_irq_enabled = false;
/*
* Allocate the IRQ
@@ -1555,6 +1623,14 @@ static int atmel_startup(struct uart_port *port)
}
/*
+ * Get the GPIO lines IRQ
+ */
+ retval = atmel_request_gpio_irq(port, atmel_port->gpio.cts_irq,
+ "atmel_cts_irq");
+ if (retval)
+ goto free_ctrl_irq;
+
+ /*
* Initialize DMA (if necessary)
*/
atmel_init_property(atmel_port, pdev);
@@ -1572,7 +1648,7 @@ 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;
/*
@@ -1618,6 +1694,11 @@ static int atmel_startup(struct uart_port *port)
}
return 0;
+
+free_ctrl_irq:
+ free_irq(port->irq, port);
+
+ return retval;
}
/*
@@ -1665,9 +1746,13 @@ static void atmel_shutdown(struct uart_port *port)
atmel_port->rx_ring.tail = 0;
/*
- * Free the interrupt
+ * Free the interrupts
*/
free_irq(port->irq, port);
+ if (atmel_port->gpio.cts_irq != INVALID_IRQ)
+ free_irq(atmel_port->gpio.cts_irq, port);
+
+ atmel_port->ms_irq_enabled = false;
}
/*
@@ -2367,6 +2452,8 @@ static int atmel_init_gpios(struct atmel_uart_port *atmel_port,
ret = atmel_request_gpio(&pdev->dev, atmel_port->gpio.rts,
"RTS", NULL);
+ ret += atmel_request_gpio(&pdev->dev, atmel_port->gpio.cts,
+ "CTS", &atmel_port->gpio.cts_irq);
return ret;
}
@@ -2406,10 +2493,15 @@ static int atmel_serial_probe(struct platform_device *pdev)
port->backup_imr = 0;
port->uart.line = ret;
port->gpio.rts = -EINVAL; /* Invalid, zero could be valid */
- if (pdata)
+ port->gpio.cts = -EINVAL;
+ port->gpio.cts_irq = INVALID_IRQ;
+ if (pdata) {
port->gpio.rts = pdata->rts_gpio;
- else if (np)
+ port->gpio.cts = pdata->cts_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);
+ }
ret = atmel_init_gpios(port, pdev);
if (ret)
diff --git a/include/linux/platform_data/atmel.h b/include/linux/platform_data/atmel.h
index e26b0c14edea..166a99ca911f 100644
--- a/include/linux/platform_data/atmel.h
+++ b/include/linux/platform_data/atmel.h
@@ -85,6 +85,7 @@ struct atmel_uart_data {
void __iomem *regs; /* virt. base address, if any */
struct serial_rs485 rs485; /* rs485 settings */
int rts_gpio; /* optional RTS GPIO */
+ int cts_gpio; /* optional CTS GPIO */
};
/* Touchscreen Controller */
--
1.8.5
--
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