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Commit 6ee04c6c authored by Vlad Lungu's avatar Vlad Lungu Committed by Greg Kroah-Hartman
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tty: xuartps: Add polled mode support for xuartps 



This allows KDB/KGDB to run.

Signed-off-by: default avatarVlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: default avatarSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0c0c47bc

drivers/tty/serial/xilinx_uartps.c

+52 −0
Original line number Diff line number Diff line
@@ -775,6 +775,54 @@ static void xuartps_enable_ms(struct uart_port *port) 
	/* N/A */

}



#ifdef CONFIG_CONSOLE_POLL

static int xuartps_poll_get_char(struct uart_port *port)

{

	u32 imr;

	int c;



	/* Disable all interrupts */

	imr = xuartps_readl(XUARTPS_IMR_OFFSET);

	xuartps_writel(imr, XUARTPS_IDR_OFFSET);



	/* Check if FIFO is empty */

	if (xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_RXEMPTY)

		c = NO_POLL_CHAR;

	else /* Read a character */

		c = (unsigned char) xuartps_readl(XUARTPS_FIFO_OFFSET);



	/* Enable interrupts */

	xuartps_writel(imr, XUARTPS_IER_OFFSET);



	return c;

}



static void xuartps_poll_put_char(struct uart_port *port, unsigned char c)

{

	u32 imr;



	/* Disable all interrupts */

	imr = xuartps_readl(XUARTPS_IMR_OFFSET);

	xuartps_writel(imr, XUARTPS_IDR_OFFSET);



	/* Wait until FIFO is empty */

	while (!(xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY))

		cpu_relax();



	/* Write a character */

	xuartps_writel(c, XUARTPS_FIFO_OFFSET);



	/* Wait until FIFO is empty */

	while (!(xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY))

		cpu_relax();



	/* Enable interrupts */

	xuartps_writel(imr, XUARTPS_IER_OFFSET);



	return;

}

#endif



/** The UART operations structure

 */

static struct uart_ops xuartps_ops = {
@@ -807,6 +855,10 @@ static struct uart_ops xuartps_ops = { 
	.config_port	= xuartps_config_port,	/* Configure when driver

						 * adds a xuartps port

						 */

#ifdef CONFIG_CONSOLE_POLL

	.poll_get_char	= xuartps_poll_get_char,

	.poll_put_char	= xuartps_poll_put_char,

#endif

};



static struct uart_port xuartps_port[2];