net: mdio: realtek-rtl9300: Add pages to info structure

The Realtek ethernet MDIO controller has a proprietary paging feature
that is closely aligned with Realtek based PHYs. These PHY know "pages"
for C22 access. Those can be switched via reads/writes to register 31.
Usually the paged access must be programmed in four steps.

1. read/save page register
2. change "page" register 31
3. read/write data register (on the given page)
4. restore page register

The controller can run all this in hardware with one single request
from the driver. It is given the page, the register and the data
and takes care of all the rest. This reduces CPU load. The number
of supported pages depend on the model. This is either 4096 for low
port count SOCs (up to 28 ports) or 8192 for high port count SOCs
(up to 56 ports).

There is however one special page that allows to pass through all C22
commands directly to the PHY - without any caching. This so called raw
page is dependent of the hardware. It is the highest supported page
number minus 1.

Provide the number of supported pages as a device specific property.
This new "num_pages" aligns with the existing properties and gives
an better insight into the hardware layout than just defining the
number of the raw page. The later directly derives from that and
can be accessed with the new RAW_PAGE() macro. Make use of it where
needed.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://patch.msgid.link/20260521175918.1494797-5-markus.stockhausen@gmx.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

0 files changed, 0 insertions, 0 deletions