Re: [PATCH net-next v2 03/14] dpll: dpllsim: Add configurable pins

[Ivan Vecera <ivecera@redhat.com>]

On 11/5/26 16:18, Petr Oros wrote:
> Pins are the unit of most DPLL netlink interaction, so let a device
> instance carry an arbitrary set of them. Each directory created under
> the pins/ group of an instance is one pin with type, frequency and
> direction attributes. The type takes the names of the DPLL pin type
> enum as iproute2 prints them, the direction is input or output and the
> frequency must be one of the frequencies the driver advertises as
> supported for the type. The pin directory name becomes the board label
> of the pin, which gives tests a stable handle to find a pin by. The
> attributes are writable only while the instance is not live and return
> EBUSY otherwise.
> 
> At live=1 the pins are ordered as created and each pin records its
> index in that order, which is the pin index it is registered under.
> Their frequencies are validated against the per type tables, a MUX pin
> configured as output is rejected since a MUX pin stands for an input
> selector, and all pin handles are obtained up front, so that a failure
> leaves nothing half visible. The device is registered first and the
> pins after it, so that every pin registration event reaches userspace
> with a valid device, and a failure unwinds exactly what was registered
> in reverse order. While the instance is live the pin items are held
> with configfs_depend_item_unlocked(), which makes rmdir of a pin fail
> with EBUSY until the instance is taken down.
> 
> The pins register with the mandatory callbacks only, direction_get and
> state_on_dpll_get, plus frequency_get since the frequency is known from
> the configuration. The input and output ops tables are identical here
> and diverge when input pins gain their setters in the next patches. The
> state is always reported as disconnected for now, the settable pin
> features follow in separate patches.
> 
> Signed-off-by: Petr Oros<poros@redhat.com>

Reviewed-by: Ivan Vecera <ivecera@redhat.com>