Re: [PATCH v8 2/5] include: linux: phy: Add phy attribute "type" and associated helpers

From: Vinod Koul <vkoul@kernel.org>
To: Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>,
	Manivannan Sadhasivam <mani@kernel.org>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-phy@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-usb@vger.kernel.org,
	Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Subject: Re: [PATCH v8 2/5] include: linux: phy: Add phy attribute "type" and associated helpers
Date: Thu, 12 Nov 2026 13:55:43 +0530	[thread overview]
Message-ID: <avV4B4g-NWtZbLuX@parshuram> (raw)
In-Reply-To: <033c8432-4a03-4f38-b0a3-28f5d551b0ef@oss.qualcomm.com>

On 27-10-26, 13:37, Krishna Kurapati wrote:
> 
> 
> On 10/9/2026 10:29 PM, Krishna Kurapati wrote:
> > 
> > 
> > On 10/5/2026 2:14 PM, Vinod Koul wrote:
> > > On 13-09-26, 20:10, Krishna Kurapati wrote:
> > > > In cases like USB High-speed phys which can be either USB2 or
> > > > EUSB2, it is
> > > > required to know the type of phy (rather than the operating
> > > > mode) because
> > > > DP and DM interrupt lines need to be configured differently for each of
> > > > them.
> > > 
> > > Does the controller care? In preceding patch you defined the EUSB2 in dt
> > > type, so this describes the hardware. So phy knows it is usb or eusb...
> > > > 
> > 
> > Controller is agnostic of whether the phy is usb2 or eusb2. Phy does now
> > its type, but it needs to communicate the same to controller.
> > 
> > > > Add support to cache the PHY_TYPE and add the following helpers:
> > > > 
> > > > - phy_set_type() for the phy drivers (like m31_eusb2 or snps-eusb2) to
> > > > declare what type of PHY they are (in this case PHY_TYPE_EUSB2).
> > > > 
> > > > - phy_get_type() for the consumers (like USB controllers) to query the
> > > > type of phy connected to them.
> > > 
> > > I am not convinced that this is the way to go... Driver already knows
> > > the type and should use it...
> > > we alreayd have mode, i am inclined to not say yes to adding type here
> > > 
> > 
> > "Mode" attribute describes the current operating scenario of the phy
> > (device mode, host mode, high speed, super speed etc.,). But it doesn't
> > describe the type of hardware and hence a new attribute.

Not really. A combo phy can be usb/type c and we do set that mode...

> > 
> 
> Vinod, can you please let know if you are fine with this approach. If yes, I
> will send v9 rebased on top of phy-next.

I am not convinced that this is the way to go..

-- 
~Vinod

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