Commit ab5e4e41 authored by Richard Genoud's avatar Richard Genoud Committed by Greg Kroah-Hartman
Browse files

tty/serial: at91: add interrupts for modem control lines 



Handle CTS/DSR/RI/DCD GPIO interrupts in atmel_serial.

Signed-off-by: default avatarRichard Genoud <richard.genoud@gmail.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e0b0baad

drivers/tty/serial/atmel_serial.c

+122 −3
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
#include <linux/gpio.h>

#include <linux/gpio/consumer.h>

#include <linux/err.h>

#include <linux/irq.h>



#include <asm/io.h>

#include <asm/ioctls.h>
@@ -167,7 +168,9 @@ struct atmel_uart_port { 


	struct serial_rs485	rs485;		/* rs485 settings */

	struct mctrl_gpios	*gpios;

	int			gpio_irq[UART_GPIO_MAX];

	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);
@@ -489,8 +492,38 @@ 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 = 0;



	/*

	 * Interrupt should not be enabled twice

	 */

	if (atmel_port->ms_irq_enabled)

		return;



	atmel_port->ms_irq_enabled = true;



	if (atmel_port->gpio_irq[UART_GPIO_CTS] >= 0)

		enable_irq(atmel_port->gpio_irq[UART_GPIO_CTS]);

	else

		ier |= ATMEL_US_CTSIC;



	if (atmel_port->gpio_irq[UART_GPIO_DSR] >= 0)

		enable_irq(atmel_port->gpio_irq[UART_GPIO_DSR]);

	else

		ier |= ATMEL_US_DSRIC;



	if (atmel_port->gpio_irq[UART_GPIO_RI] >= 0)

		enable_irq(atmel_port->gpio_irq[UART_GPIO_RI]);

	else

		ier |= ATMEL_US_RIIC;



	if (atmel_port->gpio_irq[UART_GPIO_DCD] >= 0)

		enable_irq(atmel_port->gpio_irq[UART_GPIO_DCD]);

	else

		ier |= ATMEL_US_DCDIC;



	UART_PUT_IER(port, ier);

}



/*
@@ -1079,11 +1112,31 @@ 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 = atmel_get_lines_status(port);

		pending = status & UART_GET_IMR(port);

		if (!gpio_handled) {

			/*

			 * Dealing with GPIO interrupt

			 */

			if (irq == atmel_port->gpio_irq[UART_GPIO_CTS])

				pending |= ATMEL_US_CTSIC;



			if (irq == atmel_port->gpio_irq[UART_GPIO_DSR])

				pending |= ATMEL_US_DSRIC;



			if (irq == atmel_port->gpio_irq[UART_GPIO_RI])

				pending |= ATMEL_US_RIIC;



			if (irq == atmel_port->gpio_irq[UART_GPIO_DCD])

				pending |= ATMEL_US_DCDIC;



			gpio_handled = true;

		}

		if (!pending)

			break;
@@ -1563,6 +1616,45 @@ static void atmel_get_ip_name(struct uart_port *port) 
	}

}



static void atmel_free_gpio_irq(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

	enum mctrl_gpio_idx i;



	for (i = 0; i < UART_GPIO_MAX; i++)

		if (atmel_port->gpio_irq[i] >= 0)

			free_irq(atmel_port->gpio_irq[i], port);

}



static int atmel_request_gpio_irq(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

	int *irq = atmel_port->gpio_irq;

	enum mctrl_gpio_idx i;

	int err = 0;



	for (i = 0; (i < UART_GPIO_MAX) && !err; i++) {

		if (irq[i] < 0)

			continue;



		irq_set_status_flags(irq[i], IRQ_NOAUTOEN);

		err = request_irq(irq[i], atmel_interrupt, IRQ_TYPE_EDGE_BOTH,

				  "atmel_serial", port);

		if (err)

			dev_err(port->dev, "atmel_startup - Can't get %d irq\n",

				irq[i]);

	}



	/*

	 * If something went wrong, rollback.

	 */

	while (err && (--i >= 0))

		if (irq[i] >= 0)

			free_irq(irq[i], port);



	return err;

}



/*

 * Perform initialization and enable port for reception

 */
@@ -1579,6 +1671,7 @@ 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
@@ -1590,6 +1683,13 @@ static int atmel_startup(struct uart_port *port) 
		return retval;

	}



	/*

	 * Get the GPIO lines IRQ

	 */

	retval = atmel_request_gpio_irq(port);

	if (retval)

		goto free_irq;



	/*

	 * Initialize DMA (if necessary)

	 */
@@ -1654,6 +1754,11 @@ static int atmel_startup(struct uart_port *port) 
	}



	return 0;



free_irq:

	free_irq(port->irq, port);



	return retval;

}



/*
@@ -1701,9 +1806,12 @@ 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);

	atmel_free_gpio_irq(port);



	atmel_port->ms_irq_enabled = false;

}



/*
@@ -2366,10 +2474,21 @@ static int atmel_serial_resume(struct platform_device *pdev) 


static int atmel_init_gpios(struct atmel_uart_port *p, struct device *dev)

{

	enum mctrl_gpio_idx i;

	struct gpio_desc *gpiod;



	p->gpios = mctrl_gpio_init(dev, 0);

	if (IS_ERR_OR_NULL(p->gpios))

		return -1;



	for (i = 0; i < UART_GPIO_MAX; i++) {

		gpiod = mctrl_gpio_to_gpiod(p->gpios, i);

		if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN))

			p->gpio_irq[i] = gpiod_to_irq(gpiod);

		else

			p->gpio_irq[i] = -EINVAL;

	}



	return 0;

}

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