[PATCH 4/4] tty: vt8500_serial: add polled console functions
From: Alexey Charkov <alchark@gmail.com>
Date: 2014-09-06 17:22:35
Also in:
linux-arm-kernel, linux-serial, lkml
Subsystem:
arm/vt8500 arm architecture, the rest, tty layer and serial drivers · Maintainers:
Alexey Charkov, Krzysztof Kozlowski, Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
This adds simple polling functions for single-character transmit and receive, as used by kgdb. Signed-off-by: Alexey Charkov <alchark@gmail.com> --- drivers/tty/serial/vt8500_serial.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index bfcebfd..b2bc9e8 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c@@ -566,6 +566,33 @@ static struct console vt8500_console = { #define VT8500_CONSOLE NULL #endif +#ifdef CONFIG_CONSOLE_POLL +static int vt8500_get_poll_char(struct uart_port *port) +{ + unsigned int status = vt8500_read(port, VT8500_URFIDX); + + if (!(status & 0x1f00)) + return NO_POLL_CHAR; + + return vt8500_read(port, VT8500_RXFIFO) & 0xff; +} + +static void vt8500_put_poll_char(struct uart_port *port, unsigned char c) +{ + unsigned int status, tmout = 10000; + + do { + status = vt8500_read(port, VT8500_URFIDX); + + if (--tmout == 0) + break; + udelay(1); + } while (status & 0x10); + + vt8500_write(port, c, VT8500_TXFIFO); +} +#endif + static struct uart_ops vt8500_uart_pops = { .tx_empty = vt8500_tx_empty, .set_mctrl = vt8500_set_mctrl,
@@ -583,6 +610,10 @@ static struct uart_ops vt8500_uart_pops = { .request_port = vt8500_request_port, .config_port = vt8500_config_port, .verify_port = vt8500_verify_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = vt8500_get_poll_char, + .poll_put_char = vt8500_put_poll_char, +#endif }; static struct uart_driver vt8500_uart_driver = {
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2.0.0