diff options
author | Jason Wessel <jason.wessel@windriver.com> | 2008-04-17 20:05:37 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-04-17 20:05:37 +0200 |
commit | f2d937f3bf00665ccf048b3b6616ef95859b0945 (patch) | |
tree | 6136ded0706be0d39a09a0a912e8f79a4ab63322 /drivers/char | |
parent | dc7d552705215ac50a0617fcf51bb9c736255b8e (diff) |
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>
Diffstat (limited to 'drivers/char')
-rw-r--r-- | drivers/char/tty_io.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 613ec816ce60..4d3c7018f0c3 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1155,6 +1155,48 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index) return NULL; } +#ifdef CONFIG_CONSOLE_POLL + +/** + * tty_find_polling_driver - find device of a polled tty + * @name: name string to match + * @line: pointer to resulting tty line nr + * + * This routine returns a tty driver structure, given a name + * and the condition that the tty driver is capable of polled + * operation. + */ +struct tty_driver *tty_find_polling_driver(char *name, int *line) +{ + struct tty_driver *p, *res = NULL; + int tty_line = 0; + char *str; + + mutex_lock(&tty_mutex); + /* Search through the tty devices to look for a match */ + list_for_each_entry(p, &tty_drivers, tty_drivers) { + str = name + strlen(p->name); + tty_line = simple_strtoul(str, &str, 10); + if (*str == ',') + str++; + if (*str == '\0') + str = 0; + + if (tty_line >= 0 && tty_line <= p->num && p->poll_init && + !p->poll_init(p, tty_line, str)) { + + res = p; + *line = tty_line; + break; + } + } + mutex_unlock(&tty_mutex); + + return res; +} +EXPORT_SYMBOL_GPL(tty_find_polling_driver); +#endif + /** * tty_check_change - check for POSIX terminal changes * @tty: tty to check @@ -3850,6 +3892,11 @@ void tty_set_operations(struct tty_driver *driver, driver->write_proc = op->write_proc; driver->tiocmget = op->tiocmget; driver->tiocmset = op->tiocmset; +#ifdef CONFIG_CONSOLE_POLL + driver->poll_init = op->poll_init; + driver->poll_get_char = op->poll_get_char; + driver->poll_put_char = op->poll_put_char; +#endif } |