From 30004ac9c090dcdcca99556b4587b3bad828731a Mon Sep 17 00:00:00 2001 From: Dmitry Eremin-Solenikov Date: Mon, 9 Aug 2010 18:22:49 +0400 Subject: [PATCH] tty: add tty_struct->dev pointer to corresponding device instance Some device drivers (mostly tty line disciplines) would like to have way know a struct device instance corresponding to passed tty_struct. Add a struct device pointer to struct tty_struct and populate it during initialize_tty_struct(). Signed-off-by: Dmitry Eremin-Solenikov Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/char/tty_io.c | 17 +++++++++++++++++ include/linux/tty.h | 1 + 2 files changed, 18 insertions(+) diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 613c852..dc184d4 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -183,6 +183,8 @@ struct tty_struct *alloc_tty_struct(void) void free_tty_struct(struct tty_struct *tty) { + if (tty->dev) + put_device(tty->dev); kfree(tty->write_buf); tty_buffer_free_all(tty); kfree(tty); @@ -2783,6 +2785,20 @@ void do_SAK(struct tty_struct *tty) EXPORT_SYMBOL(do_SAK); +static int dev_match_devt(struct device *dev, void *data) +{ + dev_t *devt = data; + return dev->devt == *devt; +} + +/* Must put_device() after it's unused! */ +static struct device *tty_get_device(struct tty_struct *tty) +{ + dev_t devt = tty_devnum(tty); + return class_find_device(tty_class, NULL, &devt, dev_match_devt); +} + + /** * initialize_tty_struct * @tty: tty to initialize @@ -2823,6 +2839,7 @@ void initialize_tty_struct(struct tty_struct *tty, tty->ops = driver->ops; tty->index = idx; tty_line_name(driver, idx, tty->name); + tty->dev = tty_get_device(tty); } /** diff --git a/include/linux/tty.h b/include/linux/tty.h index 67d64e6..d94eb86 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -256,6 +256,7 @@ struct tty_operations; struct tty_struct { int magic; struct kref kref; + struct device *dev; struct tty_driver *driver; const struct tty_operations *ops; int index; -- 2.7.4