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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: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
hifive-unleashed-5.1
Anton Vorontsov 2010-10-01 17:21:33 +04:00 committed by Greg Kroah-Hartman
parent 54381067ed
commit 2f8b9c15cd
1 changed files with 22 additions and 1 deletions
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23
drivers/serial/altera_uart.c
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@ -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);
free_irq(port->irq, port);
if (port->irq)
free_irq(port->irq, port);
else
del_timer_sync(&pp->tmr);
}
static const char *altera_uart_type(struct uart_port *port)