Hello, On Thu, 30 Nov 2023 22:59:32 +0300 Serge Semin <fancer.lancer@xxxxxxxxx> wrote: > On Thu, Nov 30, 2023 at 06:26:13PM +0100, Andrew Lunn wrote: > > > I will check with the xpcs maintainer how can we add indirect access > > > to the xpcs module. > > > > https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c#L449 > > > > It creates a regmap for the memory range. On top of that it creates an > > MDIO bus. You can then access the PCS in the normal way. > > Actually Synopsys DW XPCS can be synthesized with two types of the CSR > interfaces: > 1. MDIO: device looks as a normal MDIO device. This option is currently > supported by the STMMAC MDIO driver. > 2. MCI/APB3: device MMD CSRs are directly (all CSRs are visible) or > indirectly (paged-base access) accessible over the system memory bus. > > In addition to the above XPCS device can be equipped with separate > clock sources (at least to feed the MCI or APB3 interface) and may > have dedicated IRQ line to signal various events like link > establishing, failures, etc. From that perspective XPCS in both cases > looks as a normal platform device for which would be better to have a > special DT-node defined with all those resources supplied. Then the > XPCS DT-node could be passed to the DW MAC DT-node via the already > standardized "pcs-handle" DT-property. To my understanding, this should work, there's another PCS that works this way : https://elixir.bootlin.com/linux/v6.7-rc3/source/drivers/net/pcs/pcs-rzn1-miic.c Are you still able to use the mdio-regmap glue that Andrew mentioned, to avoid the duplication between the mdio and mmio register accesses ? Maxime
