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tty/serial: at91: use mctrl_gpio helpers 

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@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Richard Genoud 2014-05-13 20:20:44 +02:00 committed by Greg Kroah-Hartman
parent 84130aace8
commit e0b0baadb7
10 changed files with 88 additions and 68 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
Documentation/devicetree/bindings/serial/atmel-usart.txt
View File

@ -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.
@ -36,6 +37,11 @@ Example:
atmel,use-dma-rx;
atmel,use-dma-tx;
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:

16
arch/arm/mach-at91/at91rm9200_devices.c
View File

@ -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);

7
arch/arm/mach-at91/at91sam9260_devices.c
View File

@ -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);

4
arch/arm/mach-at91/at91sam9261_devices.c
View File

@ -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);

4
arch/arm/mach-at91/at91sam9263_devices.c
View File

@ -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);

5
arch/arm/mach-at91/at91sam9g45_devices.c
View File

@ -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);

5
arch/arm/mach-at91/at91sam9rl_devices.c
View File

@ -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);

1
drivers/tty/serial/Kconfig
View File

@ -117,6 +117,7 @@ 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.

103
drivers/tty/serial/atmel_serial.c
View File

@ -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)

1
include/linux/platform_data/atmel.h
View File

@ -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 */