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| author | Vlad Lungu <vlad.lungu@windriver.com> | 2013-10-18 01:08:07 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-20 06:47:37 +0400 |
| commit | 6ee04c6c5488b2b7fdfa22c771c127411f86e610 (patch) | |
| tree | 2b12b6cc23f1ff0ea72478e720fd2dc7983f79ff /drivers/tty/serial/xilinx_uartps.c | |
| parent | 0c0c47bc40a2e358d593b2d7fb93b50027fbfc0c (diff) | |
| download | linux-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.c | 52 |
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]; |