Re: [PATCH 2/2] phy: amlogic: meson-g12a-usb2: add S4 support
From: Manivannan Sadhasivam
Date: Sun Nov 01 2026 - 06:08:44 EST
On 2026-10-25 20:22 +0100, christian.koever-draxl@xxxxxxxxxxxxxxxxxx wrote:
> From: Christian Stefan Kövér-Draxl <ckoever@xxxxxxxxxx>
>
> The S4 USB2 PHY follows the A1 programming (MPLL DCO clock select, R21
> calibration, R13 analog settings) with a few differences taken from the
> vendor driver:
>
> - edge drive trim 2 instead of 3,
> - HS disconnect reference 3 instead of 1,
> - a disconnect threshold in R14, and the R13 PMA signal update bit
> set to latch the analog settings.
>
> Without the PMA update the host controller sees no root ports and
> nothing enumerates.
>
> Tested on an S905W2 board: devices enumerate and work behind a hub on
> the host ports.
>
> Signed-off-by: Christian Stefan Kövér-Draxl <ckoever@xxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxxxxxxxx>
- Mani