Re: [PATCH RFC net-next 4/9] net: pcs: xpcs: add Qualcomm Nord platform support

From: Andrew Lunn

Date: Wed Sep 23 2026 - 08:12:54 EST


On Wed, Sep 23, 2026 at 06:37:30AM +0530, Mohd Ayaan Anwar wrote:
> Qualcomm Nord exposes the DesignWare XPCS register blocks through
> separate direct-MMIO windows instead of the standard contiguous
> MMD/register layout. Add accessors that translate MMD accesses to the
> Nord windows:
>
> MMD 3 (PCS), standard registers: SR_XS at 0x0000

What does standard mean? 802.3 C45.2.3 defines registers 3.0 -
3.32767 as standardised.

> MMD 3 (PCS), vendor registers: VR_XS at 0x2000

and 3.32768 - 3.65535 as vendor.

However, with a length of 0x2000, there is only space for 8192 of the
standardised registers, and 0x1000 gives 4096 vendor registers.

> MMD 1 (PMA/PMD): SR_PMA at 0x3000
> MMD 31 (VEND2), standard regs: SR_MII at 0x4000

What do you mean by standard registers when talking about VEND2?

> MMD 31 (VEND2), vendor registers: VR_MII at 0x5000

Andrew