[PATCH v4 4/5] tty/serial: at91: use mctrl_gpio helpers
Richard Genoud
richard.genoud at gmail.com
Wed Feb 26 11:19:47 EST 2014
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 at gmail.com>
---
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 | 107 +++++++++++++++++++++----------
include/linux/platform_data/atmel.h | 1 -
9 files changed, 83 insertions(+), 67 deletions(-)
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..d7d873c1a1d0 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 +2364,17 @@ 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)
+{
+ int err = 0;
+
+ p->gpios = mctrl_gpio_init(dev, 0);
+ if (IS_ERR_OR_NULL(p->gpios))
+ err = PTR_ERR(p->gpios);
+
+ return err;
+}
+
static int atmel_serial_probe(struct platform_device *pdev)
{
struct atmel_uart_port *port;
@@ -2359,25 +2410,11 @@ 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
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