On Wed, Dec 11, 2024 at 08:46:16AM +0800, Xiangxu Yin wrote: > > > On 12/10/2024 11:09 PM, Dmitry Baryshkov wrote: > > On Thu, Dec 05, 2024 at 08:31:24PM +0200, Dmitry Baryshkov wrote: > >> On Thu, Dec 05, 2024 at 09:26:47PM +0800, Xiangxu Yin wrote: > >>> > >>> > >>> On 11/29/2024 10:33 PM, Dmitry Baryshkov wrote: > >>>> On Fri, 29 Nov 2024 at 09:59, Xiangxu Yin <quic_xiangxuy@xxxxxxxxxxx> wrote: > >>>>> > >>>>> Extended DP support for QCS615 USB or DP phy. Differentiated between > >>>>> USBC and DP PHY using the match table’s type, dynamically generating > >>>>> different types of cfg and layout attributes during initialization based > >>>>> on this type. Static variables are stored in cfg, while parsed values > >>>>> are organized into the layout structure. > >>>> > >>>> We didn't have an understanding / conclusion whether > >>>> qcom,usb-ssphy-qmp-usb3-or-dp PHYs are actually a single device / PHY > >>>> or two PHYs being placed next to each other. Could you please start > >>>> your commit message by explaining it? Or even better, make that a part > >>>> of the cover letter for a new series touching just the USBC PHY > >>>> driver. DP changes don't have anything in common with the PHY changes, > >>>> so you can split the series into two. > >>>> > >>> Before implement DP extension, we have discussed with abhinav and krishna about whether use combo, usbc or separate phy. > >> > >> What is "DP extension"? > >> > I'm sorry confusion casued by my description. It's means extend DP implemnt for USBC phy driver. > >>> > >>> We identified that DP and USB share some common controls for phy_mode and orientation. > >>> Specifically, 'TCSR_USB3_0_DP_PHYMODE' controls who must use the lanes - USB or DP, > >>> while PERIPH_SS_USB0_USB3PHY_PCS_MISC_TYPEC_CTRL controls the orientation. > >>> It would be more efficient for a single driver to manage these controls. > >> > >> The question is about the hardware, not about the driver. > >> > >>> Additionally, this PHY does not support Alt Mode, and the two control registers are located in separate address spaces. > >>> Therefore, even though the orientation for DP on this platform is always normal and connected to the video output board, > >>> we still decided to base it on the USBC extension. > >> > >> Could you please clarify, do usb3-or-dp PHYs support DP-over-USB-C? I > >> thought that usbc-or-dp platforms support that, but they don't > >> support DP+USB pin configuration. Note, the question is broader than > >> just QCS615, it covers the PHY type itself. > >> > >> Also, is TCSR configuration read/write or read-only? Are we supposed to > >> set the register from OS or are we supposed to read it and thus detemine > >> the PHY mode? > > > > Any updates on these two topics? > > > Still confirming detail info with HW & design team. > I’ll update the information that has been confirmed so far. > This phy support DP-over-USB-C,but it's not support alt-mode which 2 lane work for DP, other 2 lane work for USB. > TCSR phy mode is read/write reg and we can read for determine phy mode. Ok, thanks for the explanation. From my point of view: - Implement the DP PHY to be a part of the same driver. Each device supported by the usbc driver should get both PHYs. - Make sure not to break the ABI: #phy-cells = <0> should still work and return USB PHY, keeping backwards compatibility. Newer devices or upgraded DT for old devices should return USB PHY for <... 0> and DP PHY for <... 1>. - I'm not shure how to handle the USB and DP coexistence, especially in your case of the USB-or-DP PHY. -- With best wishes Dmitry
