On Fri, Feb 25, 2022 at 12:16 PM Jack Pham <quic_jackp@xxxxxxxxxxx> wrote: > > +Thinh > > Hi Peter, > > On Fri, Feb 25, 2022 at 09:54:27AM -0500, Peter Geis wrote: > > From: Bin Yang <yangbin@xxxxxxxxxxxxxx> > > > > In the 3.0 device core, if the core is programmed to operate in > > 2.0 only, then setting the GUCTL1.DEV_FORCE_20_CLK_FOR_30_CLK makes > > the internal 2.0(utmi/ulpi) clock to be routed as the 3.0 (pipe) > > clock. Enabling this feature allows the pipe3 clock to be not-running > > when forcibly operating in 2.0 device mode. > > > > Signed-off-by: Bin Yang <yangbin@xxxxxxxxxxxxxx> > > Signed-off-by: Peter Geis <pgwipeout@xxxxxxxxx> > > --- > > drivers/usb/dwc3/core.c | 4 ++++ > > drivers/usb/dwc3/core.h | 1 + > > 2 files changed, 5 insertions(+) > > > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c > > index 18adddfba3da..032d40794fae 100644 > > --- a/drivers/usb/dwc3/core.c > > +++ b/drivers/usb/dwc3/core.c > > @@ -1167,6 +1167,10 @@ static int dwc3_core_init(struct dwc3 *dwc) > > if (dwc->parkmode_disable_ss_quirk) > > reg |= DWC3_GUCTL1_PARKMODE_DISABLE_SS; > > > > + if (dwc->maximum_speed == USB_SPEED_HIGH || > > + dwc->maximum_speed == USB_SPEED_FULL) > > + reg |= DWC3_GUCTL1_DEV_FORCE_20_CLK_FOR_30_CLK; > > + > > I doubt this is applicable to all revisions of the DWC_usb3x IP cores? > For instance in the programming guide for DWC_usb31 1.90a bit 26 of > GUCTL1 is 'Reserved'. While I do see it in the DWC_usb3 databook, > table 4-8 entry "Remove pipe_clk mux for 2.0 mode?" mentions this > feature was only added in v2.90a. I was wondering about that, thanks for confirming for me. Is it possible to get a copy of this programming guide or is it closed? > > So this setting at least needs a revision check to make sure we're not > causing unexpected behavior. Something like > > DWC3_VER_IS_WITHIN(DWC3, 290A, ANY) Will do, I appreciate it. > > Jack > > > dwc3_writel(dwc->regs, DWC3_GUCTL1, reg); > > } > > > > diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h > > index eb9c1efced05..ea3ca04406bb 100644 > > --- a/drivers/usb/dwc3/core.h > > +++ b/drivers/usb/dwc3/core.h > > @@ -259,6 +259,7 @@ > > /* Global User Control 1 Register */ > > #define DWC3_GUCTL1_DEV_DECOUPLE_L1L2_EVT BIT(31) > > #define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS BIT(28) > > +#define DWC3_GUCTL1_DEV_FORCE_20_CLK_FOR_30_CLK BIT(26) > > #define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW BIT(24) > > #define DWC3_GUCTL1_PARKMODE_DISABLE_SS BIT(17) > > > > -- > > 2.25.1 > >
