From 0019b4089ccef8148d8be83cc8adfc81a75b47d4 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 8 Aug 2012 22:26:43 +0200 Subject: [PATCH] TTY: add support for unnumbered device nodes This allows drivers like ttyprintk to avoid hacks to create an unnumbered node in /dev. It used to set TTY_DRIVER_DYNAMIC_DEV in flags and call device_create on its own. That is incorrect, because TTY_DRIVER_DYNAMIC_DEV may be set only if tty_register_device is called explicitly. Signed-off-by: Jiri Slaby Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/char/ttyprintk.c | 17 ++++------------- drivers/tty/tty_io.c | 7 +++++-- include/linux/tty_driver.h | 6 ++++++ 3 files changed, 15 insertions(+), 15 deletions(-) diff --git a/drivers/char/ttyprintk.c b/drivers/char/ttyprintk.c index be1c3fb186c1..9e6272f0b98c 100644 --- a/drivers/char/ttyprintk.c +++ b/drivers/char/ttyprintk.c @@ -178,13 +178,15 @@ static struct tty_driver *ttyprintk_driver; static int __init ttyprintk_init(void) { int ret = -ENOMEM; - void *rp; tty_port_init(&tpk_port.port); tpk_port.port.ops = &null_ops; mutex_init(&tpk_port.port_write_mutex); - ttyprintk_driver = alloc_tty_driver(1); + ttyprintk_driver = tty_alloc_driver(1, + TTY_DRIVER_RESET_TERMIOS | + TTY_DRIVER_REAL_RAW | + TTY_DRIVER_UNNUMBERED_NODE); if (!ttyprintk_driver) return ret; @@ -195,8 +197,6 @@ static int __init ttyprintk_init(void) ttyprintk_driver->type = TTY_DRIVER_TYPE_CONSOLE; ttyprintk_driver->init_termios = tty_std_termios; ttyprintk_driver->init_termios.c_oflag = OPOST | OCRNL | ONOCR | ONLRET; - ttyprintk_driver->flags = TTY_DRIVER_RESET_TERMIOS | - TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; tty_set_operations(ttyprintk_driver, &ttyprintk_ops); ret = tty_register_driver(ttyprintk_driver); @@ -205,15 +205,6 @@ static int __init ttyprintk_init(void) goto error; } - /* create our unnumbered device */ - rp = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 3), NULL, - ttyprintk_driver->name); - if (IS_ERR(rp)) { - printk(KERN_ERR "Couldn't create ttyprintk device\n"); - ret = PTR_ERR(rp); - goto error; - } - return 0; error: diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index a67609b9f21b..4d9898c2b641 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1216,7 +1216,10 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p) */ static void tty_line_name(struct tty_driver *driver, int index, char *p) { - sprintf(p, "%s%d", driver->name, index + driver->name_base); + if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) + strcpy(p, driver->name); + else + sprintf(p, "%s%d", driver->name, index + driver->name_base); } /** @@ -3076,7 +3079,7 @@ struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, struct tty_driver *driver; int err; - if (!lines) + if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) return ERR_PTR(-EINVAL); driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 1a85f003d646..44e05b75d573 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -394,6 +394,11 @@ static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) * TTY_DRIVER_DYNAMIC_ALLOC -- do not allocate structures which are * needed per line for this driver as it would waste memory. * The driver will take care. + * + * TTY_DRIVER_UNNUMBERED_NODE -- do not create numbered /dev nodes. In + * other words create /dev/ttyprintk and not /dev/ttyprintk0. + * Applicable only when a driver for a single tty device is + * being allocated. */ #define TTY_DRIVER_INSTALLED 0x0001 #define TTY_DRIVER_RESET_TERMIOS 0x0002 @@ -402,6 +407,7 @@ static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) #define TTY_DRIVER_DEVPTS_MEM 0x0010 #define TTY_DRIVER_HARDWARE_BREAK 0x0020 #define TTY_DRIVER_DYNAMIC_ALLOC 0x0040 +#define TTY_DRIVER_UNNUMBERED_NODE 0x0080 /* tty driver types */ #define TTY_DRIVER_TYPE_SYSTEM 0x0001 -- 2.20.1