On Tue, Jul 14, 2026 at 07:04:08PM +0000, Shenwei Wang (OSS) wrote: > > > > -----Original Message----- > > From: Mathieu Poirier <[email protected]> > > Sent: Monday, July 13, 2026 12:17 PM > > To: Shenwei Wang (OSS) <[email protected]> > > Cc: Linus Walleij <[email protected]>; Bartosz Golaszewski > > <[email protected]>; > > Jonathan Corbet <[email protected]>; Rob Herring <[email protected]>; Krzysztof > > Kozlowski <[email protected]>; Conor Dooley <[email protected]>; Bjorn > > Andersson <[email protected]>; Frank Li <[email protected]>; Sascha Hauer > > <[email protected]>; Shuah Khan <[email protected]>; linux- > > [email protected]; [email protected]; > > [email protected]; > > Pengutronix Kernel Team <[email protected]>; Fabio Estevam > > <[email protected]>; Shenwei Wang <[email protected]>; Peng Fan > > <[email protected]>; [email protected]; linux- > > [email protected]; [email protected]; linux-arm- > > [email protected]; dl-linux-imx <[email protected]>; Arnaud > > POULIQUEN <[email protected]>; [email protected]; Andrew Lunn > > <[email protected]> > > Subject: Re: [PATCH v14 1/5] docs: driver-api: gpio: rpmsg gpio driver over > > rpmsg > > bus > > > > > + > > > +The RPMSG message consists of a 8-byte packet with the following layout: > > > + > > > +.. code-block:: none > > > +.. code-block:: none > > > + > > > + +------+------+--------+ > > > + | 0x00 | 0x01 | 0x02 | > > > + | 2 | line | trigger| > > > + +------+------+--------+ > > > > 2 things here: > > > > 1) You did not include messages that mask and unmask interrupts at the > > driver > > side. > > > > 2) We are carrying virtio-gpio messages on top of RPMSG and as such, this > > whole > > protocol should be about thar: > > > > +------+------+--------+-------- > > | 0x00 | payload | > > | Q | | > > +------+------+--------+-------- > > > > Q = 0 requestq > > Q = 1 eventq > > > > The "payload" part is simply the format of the messages as found in the > > virtio- > > gpio specification. From there, the only thing left to mention is which > > messages > > are not supported, i.e get line names. > > > > > + > > > +- **line**: The GPIO line (pin) index of the port. > > > + > > > +- **trigger**: Optional parameter to indicate the trigger event type. > > > > Not part of the spec - remove. > > > > The two fields above are required for rpmsg-gpio, but not for virtio-gpio.
I agree that the line is required but not the trigger. The driver (using the same terminology as the specification) knows what trigger the pin has been configured for. Adding the trigger information to the interrupt notification is redundant. > > In the rpmsg-gpio case, interrupt detection and handling occur on the remote > processor. The > interrupt information (such as the GPIO line and trigger type) must therefore > be sent to Linux > through this notification message. > > In contrast, for virtio-gpio, interrupt handling is performed on the local > processor. Since Linux already > has all the necessary interrupt context, the information is not needed. > > Shenwei > > > Given the refactoring work that is still needed, I will not look at the > > implementation. > > > > Thanks, > > Mathieu > > > > > + > > > diff --git a/Documentation/driver-api/gpio/index.rst > > > b/Documentation/driver-api/gpio/index.rst > > > index bee58f709b9a..e5eb1f82f01f 100644 > > > --- a/Documentation/driver-api/gpio/index.rst > > > +++ b/Documentation/driver-api/gpio/index.rst > > > @@ -16,6 +16,7 @@ Contents: > > > drivers-on-gpio > > > bt8xxgpio > > > pca953x > > > + gpio-rpmsg > > > > > > Core > > > ==== > > > -- > > > 2.43.0 > > >
