Re: [PATCH v6 12/17] phy: sun4i-usb: Introduce port2 SIDDQ quirk

From: Maxime Ripard
Date: Mon May 24 2021 - 07:59:54 EST


Hi

On Wed, May 19, 2021 at 11:41:47AM +0100, Andre Przywara wrote:
> At least the Allwinner H616 SoC requires a weird quirk to make most
> USB PHYs work: Only port2 works out of the box, but all other ports
> need some help from this port2 to work correctly: The CLK_BUS_PHY2 and
> RST_USB_PHY2 clock and reset need to be enabled, and the SIDDQ bit in
> the PMU PHY control register needs to be cleared. For this register to
> be accessible, CLK_BUS_ECHI2 needs to be ungated. Don't ask ....
>
> Instead of disguising this as some generic feature, do exactly that
> in our PHY init:
> If the quirk bit is set, and we initialise a PHY other than PHY2, ungate
> this one special clock, and clear the SIDDQ bit. We can pull in the
> other required clocks via the DT.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>

What is this SIDDQ bit doing exactly?

I guess we could also expose this using a power-domain if it's relevant?

Maxime

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