Re: [RFC v4 2/5] usb: dwc3: core: Refactor PHY logic to support Multiport Controller

[Krishna Kurapati PSSNV]

On 1/21/2023 4:27 AM, Thinh Nguyen wrote:
> On Thu, Jan 19, 2023, Thinh Nguyen wrote:
> > Hi,
> >
> > On Sun, Jan 15, 2023, Krishna Kurapati wrote:
> > > Currently the DWC3 driver supports only single port controller
> > > which requires at most one HS and one SS PHY.
> >
> > Add note here that multi-port is for host mode for clarity.
> >
> > > But the DWC3 USB controller can be connected to multiple ports and
> > > each port can have their own PHYs. Each port of the multiport
> > > controller can either be HS+SS capable or HS only capable
> > > Proper quantification of them is required to modify GUSB2PHYCFG
> > > and GUSB3PIPECTL registers appropriately.
> > >
> > > Add support for detecting, obtaining and configuring phy's supported
> > > by a multiport controller and limit the max number of ports
> > > supported to 4.
> > >
> > > Signed-off-by: Harsh Agarwal <quic_harshq@xxxxxxxxxxx>
> > > Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
> > > ---
> > >   drivers/usb/dwc3/core.c | 304 +++++++++++++++++++++++++++++-----------
> > >   drivers/usb/dwc3/core.h |  15 +-
> > >   drivers/usb/dwc3/drd.c  |  14 +-
> > >   3 files changed, 244 insertions(+), 89 deletions(-)
> > >
> > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > > index 476b63618511..7e0a9a598dfd 100644
> > > --- a/drivers/usb/dwc3/core.c
> > > +++ b/drivers/usb/dwc3/core.c
> > > @@ -120,7 +120,7 @@ static void __dwc3_set_mode(struct work_struct *work)
> > >   {
> > >   	struct dwc3 *dwc = work_to_dwc(work);
> > >   	unsigned long flags;
> > > -	int ret;
> > > +	int ret, i;
> >
> > Can we declare variables in separate lines here and other places.
> >
> > >   	u32 reg;
> > >   	u32 desired_dr_role;
> > >   
> > > @@ -200,8 +200,10 @@ static void __dwc3_set_mode(struct work_struct *work)
> > >   		} else {
> > >   			if (dwc->usb2_phy)
> > >   				otg_set_vbus(dwc->usb2_phy->otg, true);
> > > -			phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
> > > -			phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
> > > +			for (i = 0; i < dwc->num_ports; i++) {
>
> BTW, is num_ports the total of usb2 + usb3 ports?
Hi Thinh,

  No, num_ports is just the total number of hw usb ports present 
(presuming each port is hs capable, this is just the number of HS Phy's 
available).

Regards,
KRishna,
> > > +				phy_set_mode(dwc->usb2_generic_phy[i], PHY_MODE_USB_HOST);
> > > +				phy_set_mode(dwc->usb3_generic_phy[i], PHY_MODE_USB_HOST);
> > > +			}
> > >   			if (dwc->dis_split_quirk) {
>
> Thanks,
> Thinh