Re: [PATCH 08/10] tty_io: export tty_class

Dmitry Eremin-Solenikov
2009-06-02T14:23:10Z

On Mon, Jun 01, 2009 at 04:34:18PM +0100, Alan Cox wrote:
> > I used class_find_device finding the device with matching minor. Will it be
> > acceptable, if I just move this code into tty_* file and export it as
> > to modules?
>
> Yes - create a proper tty helper function for doing the job and document
> what it does. That way if the tty layer is changed it is obvious that
> this code also needs considering.

Is this suitable:

>From bea1f7dd279119a1aa60556ff0441e31c92876aa Mon Sep 17 00:00:00 2001
From: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Date: Tue, 2 Jun 2009 06:31:35 +0400
Subject: [PATCH] tty_io: add an API to get device corresponding to tty_struct

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---
drivers/char/tty_io.c | 13 +++++++++++++
include/linux/tty.h | 1 +
2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 66b99a2..04d6c9a 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -3026,6 +3026,19 @@ dev_t tty_devnum(struct tty_struct *tty)
}
EXPORT_SYMBOL(tty_devnum);

+static int dev_match_devt(struct device *dev, void *data)
+{
+ dev_t *devt = data;
+ return dev->devt == *devt;
+}
+
+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);
+}
+EXPORT_SYMBOL(tty_get_device);
+
void proc_clear_tty(struct task_struct *p)
{
unsigned long flags;
diff --git a/include/linux/tty.h b/include/linux/tty.h
index fc39db9..d17ba1e 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -413,6 +413,7 @@ extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg);
extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
extern dev_t tty_devnum(struct tty_struct *tty);
+struct device *tty_get_device(struct tty_struct *tty);
extern void proc_clear_tty(struct task_struct *p);
extern struct tty_struct *get_current_tty(void);
extern void tty_default_fops(struct file_operations *fops);
--
1.6.3.1

--
With best wishes
Dmitry