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Commit 2f8b9c15 authored by Anton Vorontsov's avatar Anton Vorontsov Committed by Greg Kroah-Hartman
Browse files

altera_uart: Add support for polling mode (IRQ-less) 



Some Altera UART implementations doesn't route the IRQ line, so we have
to work in polling mode.

Signed-off-by: default avatarAnton Vorontsov <cbouatmailru@gmail.com>
Acked-by: default avatarTobias Klauser <tklauser@distanz.ch>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 54381067

drivers/serial/altera_uart.c

+22 −1
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 


#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/timer.h>

#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/console.h>
@@ -76,6 +77,7 @@ 
 */

struct altera_uart {

	struct uart_port port;

	struct timer_list tmr;

	unsigned int sigs;	/* Local copy of line sigs */

	unsigned short imr;	/* Local IMR mirror */

};
@@ -168,6 +170,7 @@ static void altera_uart_set_termios(struct uart_port *port, 
	tty_termios_encode_baud_rate(termios, baud, baud);



	spin_lock_irqsave(&port->lock, flags);

	uart_update_timeout(port, termios->c_cflag, baud);

	writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG);

	spin_unlock_irqrestore(&port->lock, flags);

}
@@ -268,6 +271,15 @@ static irqreturn_t altera_uart_interrupt(int irq, void *data) 
	return IRQ_RETVAL(isr);

}



static void altera_uart_timer(unsigned long data)

{

	struct uart_port *port = (void *)data;

	struct altera_uart *pp = container_of(port, struct altera_uart, port);



	altera_uart_interrupt(0, port);

	mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));

}



static void altera_uart_config_port(struct uart_port *port, int flags)

{

	port->type = PORT_ALTERA_UART;
@@ -284,6 +296,12 @@ static int altera_uart_startup(struct uart_port *port) 
	unsigned long flags;

	int ret;



	if (!port->irq) {

		setup_timer(&pp->tmr, altera_uart_timer, (unsigned long)port);

		mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));

		return 0;

	}



	ret = request_irq(port->irq, altera_uart_interrupt, IRQF_DISABLED,

			DRV_NAME, port);

	if (ret) {
@@ -316,7 +334,10 @@ static void altera_uart_shutdown(struct uart_port *port) 


	spin_unlock_irqrestore(&port->lock, flags);



	if (port->irq)

		free_irq(port->irq, port);

	else

		del_timer_sync(&pp->tmr);

}



static const char *altera_uart_type(struct uart_port *port)