| Message ID | 20230926093607.59536-2-fe@dev.tdt.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ledtrig-tty: add new state evaluation | expand |
On 26. 09. 23, 11:36, Florian Eckert wrote: > The struct 'tty_struct' has a callback to read the status flags of the tty > if the tty driver provides them. So fare, the data is transferred directly > to userspace with the function 'tty_tiocmget'. This function cannot be > used to evaluate the status line of the tty interface in the ledtrig-tty > trigger. To make this possible, a new function must be added that does > not immediately pass the data on to userspace. > > The new function 'tty_get_mget' only returns the status register. > This information can then be processed further in the ledtrig-tty > trigger. > > Signed-off-by: Florian Eckert <fe@dev.tdt.de> > --- > drivers/tty/tty_io.c | 29 +++++++++++++++++++++++------ > include/linux/tty.h | 1 + > 2 files changed, 24 insertions(+), 6 deletions(-) > > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c > index 8a94e5a43c6d..8070ed0ce41f 100644 > --- a/drivers/tty/tty_io.c > +++ b/drivers/tty/tty_io.c > @@ -2494,6 +2494,25 @@ static int send_break(struct tty_struct *tty, unsigned int duration) > return retval; > } > > +/** > + * tty_get_mget - get modem status Heh, the naming is funny. It apparently comes from tiocmget. But that comes from: tty ioctl modem get (TIOCMGET) tty ioctl modem set (TIOCMSET) So you should name it like tty_get_modem() not get_mget(). Also those extra spaces around "-" caused some issues in the generated output and should be removed (everywhere). > + * @tty: tty device > + * > + * Obtain the modem status bits from the tty driver if the feature > + * is supported. > + * Superfluous empty line here. > + */ > +int tty_get_mget(struct tty_struct *tty) > +{ > + int retval = -ENOTTY; > + > + if (tty->ops->tiocmget) > + retval = tty->ops->tiocmget(tty); > + > + return retval; > +} > +EXPORT_SYMBOL_GPL(tty_get_mget); thanks,
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 8a94e5a43c6d..8070ed0ce41f 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2494,6 +2494,25 @@ static int send_break(struct tty_struct *tty, unsigned int duration) return retval; } +/** + * tty_get_mget - get modem status + * @tty: tty device + * + * Obtain the modem status bits from the tty driver if the feature + * is supported. + * + */ +int tty_get_mget(struct tty_struct *tty) +{ + int retval = -ENOTTY; + + if (tty->ops->tiocmget) + retval = tty->ops->tiocmget(tty); + + return retval; +} +EXPORT_SYMBOL_GPL(tty_get_mget); + /** * tty_tiocmget - get modem status * @tty: tty device @@ -2506,14 +2525,12 @@ static int send_break(struct tty_struct *tty, unsigned int duration) */ static int tty_tiocmget(struct tty_struct *tty, int __user *p) { - int retval = -ENOTTY; + int retval; - if (tty->ops->tiocmget) { - retval = tty->ops->tiocmget(tty); + retval = tty_get_mget(tty); + if (retval >= 0) + retval = put_user(retval, p); - if (retval >= 0) - retval = put_user(retval, p); - } return retval; } diff --git a/include/linux/tty.h b/include/linux/tty.h index f002d0f25db7..7b9edd4a7007 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -421,6 +421,7 @@ int tty_unthrottle_safe(struct tty_struct *tty); int tty_do_resize(struct tty_struct *tty, struct winsize *ws); int tty_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount); +int tty_get_mget(struct tty_struct *tty); int is_current_pgrp_orphaned(void); void tty_hangup(struct tty_struct *tty); void tty_vhangup(struct tty_struct *tty);
The struct 'tty_struct' has a callback to read the status flags of the tty if the tty driver provides them. So fare, the data is transferred directly to userspace with the function 'tty_tiocmget'. This function cannot be used to evaluate the status line of the tty interface in the ledtrig-tty trigger. To make this possible, a new function must be added that does not immediately pass the data on to userspace. The new function 'tty_get_mget' only returns the status register. This information can then be processed further in the ledtrig-tty trigger. Signed-off-by: Florian Eckert <fe@dev.tdt.de> --- drivers/tty/tty_io.c | 29 +++++++++++++++++++++++------ include/linux/tty.h | 1 + 2 files changed, 24 insertions(+), 6 deletions(-)