consoles: polling support, kgdboc
polled console handling support, to access a console in an irq-less
way while in debug or irq context.
absolutely zero impact as long as CONFIG_CONSOLE_POLL is disabled.
(which is the default)
[ jan.kiszka@siemens.com: lots of cleanups ]
[ mingo@elte.hu: redesign, splitups, cleanups. ]
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 0f5a179..4d7eecb 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1827,7 +1827,7 @@
* options. The format of the string is <baud><parity><bits><flow>,
* eg: 115200n8r
*/
-void __init
+void
uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
{
char *s = options;
@@ -1842,6 +1842,7 @@
if (*s)
*flow = *s;
}
+EXPORT_SYMBOL_GPL(uart_parse_options);
struct baud_rates {
unsigned int rate;
@@ -1872,7 +1873,7 @@
* @bits: number of data bits
* @flow: flow control character - 'r' (rts)
*/
-int __init
+int
uart_set_options(struct uart_port *port, struct console *co,
int baud, int parity, int bits, int flow)
{
@@ -1924,10 +1925,16 @@
port->mctrl |= TIOCM_DTR;
port->ops->set_termios(port, &termios, &dummy);
- co->cflag = termios.c_cflag;
+ /*
+ * Allow the setting of the UART parameters with a NULL console
+ * too:
+ */
+ if (co)
+ co->cflag = termios.c_cflag;
return 0;
}
+EXPORT_SYMBOL_GPL(uart_set_options);
#endif /* CONFIG_SERIAL_CORE_CONSOLE */
static void uart_change_pm(struct uart_state *state, int pm_state)
@@ -2182,6 +2189,60 @@
}
}
+#ifdef CONFIG_CONSOLE_POLL
+
+static int uart_poll_init(struct tty_driver *driver, int line, char *options)
+{
+ struct uart_driver *drv = driver->driver_state;
+ struct uart_state *state = drv->state + line;
+ struct uart_port *port;
+ int baud = 9600;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if (!state || !state->port)
+ return -1;
+
+ port = state->port;
+ if (!(port->ops->poll_get_char && port->ops->poll_put_char))
+ return -1;
+
+ if (options) {
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+ return uart_set_options(port, NULL, baud, parity, bits, flow);
+ }
+
+ return 0;
+}
+
+static int uart_poll_get_char(struct tty_driver *driver, int line)
+{
+ struct uart_driver *drv = driver->driver_state;
+ struct uart_state *state = drv->state + line;
+ struct uart_port *port;
+
+ if (!state || !state->port)
+ return -1;
+
+ port = state->port;
+ return port->ops->poll_get_char(port);
+}
+
+static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
+{
+ struct uart_driver *drv = driver->driver_state;
+ struct uart_state *state = drv->state + line;
+ struct uart_port *port;
+
+ if (!state || !state->port)
+ return;
+
+ port = state->port;
+ port->ops->poll_put_char(port, ch);
+}
+#endif
+
static const struct tty_operations uart_ops = {
.open = uart_open,
.close = uart_close,
@@ -2206,6 +2267,11 @@
#endif
.tiocmget = uart_tiocmget,
.tiocmset = uart_tiocmset,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_init = uart_poll_init,
+ .poll_get_char = uart_poll_get_char,
+ .poll_put_char = uart_poll_put_char,
+#endif
};
/**
