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authorVlad Lungu <vlad.lungu@windriver.com>2013-10-18 01:08:07 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-20 06:47:37 +0400
commit6ee04c6c5488b2b7fdfa22c771c127411f86e610 (patch)
tree2b12b6cc23f1ff0ea72478e720fd2dc7983f79ff /drivers/tty/serial/xilinx_uartps.c
parent0c0c47bc40a2e358d593b2d7fb93b50027fbfc0c (diff)
downloadlinux-6ee04c6c5488b2b7fdfa22c771c127411f86e610.tar.xz
tty: xuartps: Add polled mode support for xuartps
This allows KDB/KGDB to run. Signed-off-by: Vlad Lungu <vlad.lungu@windriver.com> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/xilinx_uartps.c')
-rw-r--r--drivers/tty/serial/xilinx_uartps.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 5d5557af4d22..62259f37ddda 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -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];