Re: [PATCH v6 1/5] dt-bindings: phy: Add PHY_TYPE_EUSB2 definition

[Krzysztof Kozlowski <krzk@kernel.org>]

On Wed, Aug 26, 2026 at 10:32:51PM +0530, Krishna Kurapati wrote:
> eUSB2 (Embedded USB2) is a MIPI Alliance standard for chip-to-chip USB2
> signaling. Unlike standard USB2, which uses 3.3V signaling, eUSB2 uses
> low-voltage differential signaling (~0.4V) and requires a repeater to
> interface with external USB2 ports. Because of these differences, eUSB2
> PHY initialization sequences, voltage tuning, and register configuration
> are distinct from USB2.
> 
> Additionally, eUSB2 targets handle wakeup interrupts differently
> depending on device speed when operating in host mode. According to the
> eUSB2 specification, remote wakeup signaling in host mode is detected
> via different data-line assertions based on the connected device speed:
> 
> - Low-speed devices: the host repeater drives eD+ to logic '1' upon
>   detecting a K-state on the USB lines during remote wakeup (eUSB2
>   spec, Section 5.5.14).
> - Full-speed/high-speed devices: the host repeater drives eD- to
>   logic '1' upon detecting a K-state during remote wakeup (eUSB2 spec,
>    Sections 5.5.15 and 5.5.18).
> 
> Since the eUSB2 PHY's DP and DM lines need to be configured differently
> from USB2 PHYs, controllers should be able to query the PHY type and
> configure wakeup interrupts accordingly.
> 
> Add PHY_TYPE_EUSB2 to distinguish eUSB2 PHYs from standard USB2 PHYs.
> 
> Signed-off-by: Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>
> ---
>  include/dt-bindings/phy/phy.h | 1 +
>  1 file changed, 1 insertion(+)

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof


-- 
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy