From 2f8b9c15cd88ce22bd80e6eb3988dbaa49f1efd3 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Fri, 1 Oct 2010 17:21:33 +0400 Subject: [PATCH] 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 Acked-by: Tobias Klauser Cc: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/serial/altera_uart.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/serial/altera_uart.c b/drivers/serial/altera_uart.c index f8d8a00554da..7dd58da0ddf5 100644 --- a/drivers/serial/altera_uart.c +++ b/drivers/serial/altera_uart.c @@ -15,6 +15,7 @@ #include #include +#include #include #include #include @@ -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) -- 2.20.1