On Sat, Jun 20, 2020 at 12:49:00PM -0500, minyard@xxxxxxx wrote: > From: Corey Minyard <cminyard@xxxxxxxxxx> > > Document the read, poll, and async operations. > > Signed-off-by: Corey Minyard <cminyard@xxxxxxxxxx> > --- > Documentation/watchdog/watchdog-kernel-api.rst | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/Documentation/watchdog/watchdog-kernel-api.rst b/Documentation/watchdog/watchdog-kernel-api.rst > index 068a55ee0d4a..aa15a2d35397 100644 > --- a/Documentation/watchdog/watchdog-kernel-api.rst > +++ b/Documentation/watchdog/watchdog-kernel-api.rst > @@ -132,6 +132,10 @@ The list of watchdog operations is defined as:: > unsigned int (*get_timeleft)(struct watchdog_device *); > int (*restart)(struct watchdog_device *); > long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long); > + ssize_t (*read)(struct watchdog_device *, struct file *, char __user *, > + size_t, loff_t *); > + __poll_t (*poll)(struct watchdog_device *, struct file *, poll_table *); > + int (*fasync)(struct watchdog_device *, int, struct file *, int); > }; > > It is important that you first define the module owner of the watchdog timer > @@ -235,6 +239,14 @@ they are supported. These optional routines/operations are: > our own internal ioctl call handling. This routine should return -ENOIOCTLCMD > if a command is not supported. The parameters that are passed to the ioctl > call are: watchdog_device, cmd and arg. > +* read: If a read call comes in on the watchdog device, call this function. > + This allows a watchdog to provide data to the user. I don't think this makes any sense. To be accepted, this would need to be standardized. We can't have userspace read from a watchdog device without knowing what is going to be returned. Guenter > +* poll: If a poll call comes in on the watchdog device, call this. This > + allows the user to do select/poll waiting on the device to have read data > + ready. > +* fasync: If a fasync call comes in on the watchdog, call this. This > + allows the user to do async operations waiting for read data from > + the device. > > The status bits should (preferably) be set with the set_bit and clear_bit alike > bit-operations. The status bits that are defined are: > -- > 2.17.1 >
