From: John Stultz <john.stultz@linaro.org>
To: Jack Pham <jackp@codeaurora.org>
Cc: Yu Chen <chenyu56@huawei.com>, Felipe Balbi <balbi@kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andy Shevchenko <andy.shevchenko@gmail.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
Chunfeng Yun <chunfeng.yun@mediatek.com>,
Linux USB List <linux-usb@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>
Subject: Re: [RFC][PATCH v2 2/5] usb: dwc3: Execute GCTL Core Soft Reset while switch mdoe for Hisilicon Kirin Soc
Date: Mon, 7 Oct 2019 16:53:33 -0700 [thread overview]
Message-ID: <CALAqxLWG0a_sRu08XL7q4MpD1ZfAEhVb3mKQ0FLAe8kjO2PV3A@mail.gmail.com> (raw)
In-Reply-To: <20191007233904.GC9754@jackp-linux.qualcomm.com>
On Mon, Oct 7, 2019 at 4:39 PM Jack Pham <jackp@codeaurora.org> wrote:
>
> Hi John, Yu, Felipe,
>
> On Mon, Oct 07, 2019 at 05:55:50PM +0000, John Stultz wrote:
> > From: Yu Chen <chenyu56@huawei.com>
> >
> > A GCTL soft reset should be executed when switch mode for dwc3 core
> > of Hisilicon Kirin Soc.
> >
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Felipe Balbi <balbi@kernel.org>
> > Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: Yu Chen <chenyu56@huawei.com>
> > Cc: Matthias Brugger <matthias.bgg@gmail.com>
> > Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > Cc: linux-usb@vger.kernel.org
> > Cc: devicetree@vger.kernel.org
> > Signed-off-by: Yu Chen <chenyu56@huawei.com>
> > Signed-off-by: John Stultz <john.stultz@linaro.org>
> > ---
> > drivers/usb/dwc3/core.c | 20 ++++++++++++++++++++
> > drivers/usb/dwc3/core.h | 3 +++
> > 2 files changed, 23 insertions(+)
> >
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index 999ce5e84d3c..440261432421 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -112,6 +112,19 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
> > dwc->current_dr_role = mode;
> > }
> >
> > +static void dwc3_gctl_core_soft_reset(struct dwc3 *dwc)
> > +{
> > + u32 reg;
> > +
> > + reg = dwc3_readl(dwc->regs, DWC3_GCTL);
> > + reg |= DWC3_GCTL_CORESOFTRESET;
> > + dwc3_writel(dwc->regs, DWC3_GCTL, reg);
> > +
> > + reg = dwc3_readl(dwc->regs, DWC3_GCTL);
> > + reg &= ~DWC3_GCTL_CORESOFTRESET;
> > + dwc3_writel(dwc->regs, DWC3_GCTL, reg);
> > +}
> > +
> > static void __dwc3_set_mode(struct work_struct *work)
> > {
> > struct dwc3 *dwc = work_to_dwc(work);
> > @@ -156,6 +169,10 @@ static void __dwc3_set_mode(struct work_struct *work)
> >
> > dwc3_set_prtcap(dwc, dwc->desired_dr_role);
> >
> > + /* Execute a GCTL Core Soft Reset when switch mode */
> > + if (dwc->gctl_reset_quirk)
> > + dwc3_gctl_core_soft_reset(dwc);
> > +
>
> In fact it is mentioned in the Synopsys databook to perform a GCTL
> CoreSoftReset when changing the PrtCapDir between device & host modes.
> So I think this should apply generally without a quirk. Further, it
> states to do this *prior* to writing PrtCapDir, so should it go before
> dwc3_set_prtcap() instead?
Sounds good. I have no such access to the hardware docs, so I really
appreciate your input here!
I'll refactor it as you describe and remove the quirk flag.
thanks
-john
next prev parent reply other threads:[~2019-10-07 23:53 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-07 17:55 [RFC][PATCH v2 0/5] dwc3: Changes for HiKey960 support John Stultz
2019-10-07 17:55 ` [RFC][PATCH v2 1/5] dt-bindings: usb: dwc3: Add a property to do a CGTL soft reset on mode switching John Stultz
2019-10-07 17:55 ` [RFC][PATCH v2 2/5] usb: dwc3: Execute GCTL Core Soft Reset while switch mdoe for Hisilicon Kirin Soc John Stultz
2019-10-07 23:39 ` Jack Pham
2019-10-07 23:53 ` John Stultz [this message]
2019-10-07 17:55 ` [RFC][PATCH v2 3/5] usb: dwc3: Increase timeout for CmdAct cleared by device controller John Stultz
2019-10-07 17:55 ` [RFC][PATCH v2 4/5] dt-bindings: usb: dwc3: of-simple: add compatible for HiSi John Stultz
2019-10-07 18:38 ` Rob Herring
2019-10-07 19:06 ` John Stultz
2019-10-07 21:11 ` Rob Herring
2019-10-07 23:00 ` John Stultz
2019-10-11 15:51 ` Rob Herring
2019-10-15 3:57 ` John Stultz
2019-10-15 11:40 ` Rob Herring
2019-10-07 17:55 ` [RFC][PATCH v2 5/5] usb: dwc3: dwc3-of-simple: Add support for dwc3 of Hisilicon Soc Platform John Stultz
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