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From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
To: Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
Cc: Johan Hovold <johan@kernel.org>,
	Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Felipe Balbi <balbi@kernel.org>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-arm-msm@vger.kernel.org" <linux-arm-msm@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"quic_pkondeti@quicinc.com" <quic_pkondeti@quicinc.com>,
	"quic_ppratap@quicinc.com" <quic_ppratap@quicinc.com>,
	"quic_wcheng@quicinc.com" <quic_wcheng@quicinc.com>,
	"quic_jackp@quicinc.com" <quic_jackp@quicinc.com>,
	"quic_harshq@quicinc.com" <quic_harshq@quicinc.com>,
	"ahalaney@redhat.com" <ahalaney@redhat.com>
Subject: Re: [PATCH v8 3/9] usb: dwc3: core: Access XHCI address space temporarily to read port info
Date: Wed, 17 May 2023 03:21:24 +0000	[thread overview]
Message-ID: <20230517032124.rdh7ehnair3wjuvm@synopsys.com> (raw)
In-Reply-To: <cacc5813-404a-c2ef-e768-20f2acd696d9@quicinc.com>

On Wed, May 17, 2023, Krishna Kurapati PSSNV wrote:
> 
> 
> On 5/16/2023 8:32 PM, Krishna Kurapati PSSNV wrote:
> > 
> > 
> > On 5/16/2023 5:41 PM, Johan Hovold wrote:
> > > On Sun, May 14, 2023 at 11:19:11AM +0530, Krishna Kurapati wrote:
> > > > Currently host-only capable DWC3 controllers support Multiport.
> > > > Temporarily map XHCI address space for host-only controllers and parse
> > > > XHCI Extended Capabilities registers to read number of usb2 ports and
> > > > usb3 ports present on multiport controller. Each USB Port is at least HS
> > > > capable.
> > > > 
> > > > The port info for usb2 and usb3 phy are identified as num_usb2_ports
> > > > and num_usb3_ports. The intention is as follows:
> > > > 
> > > > Wherever we need to perform phy operations like:
> > > > 
> > > > LOOP_OVER_NUMBER_OF_AVAILABLE_PORTS()
> > > > {
> > > >     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 number of usb2 ports is 3, loop can go from index 0-2 for
> > > > usb2_generic_phy. If number of usb3-ports is 2, we don't know for sure,
> > > > if the first 2 ports are SS capable or some other ports like (2 and 3)
> > > > are SS capable. So instead, num_usb2_ports is used to loop around all
> > > > phy's (both hs and ss) for performing phy operations. If any
> > > > usb3_generic_phy turns out to be NULL, phy operation just bails out.
> > > > 
> > > > num_usb3_ports is used to modify GUSB3PIPECTL registers while setting up
> > > > phy's as we need to know how many SS capable ports are there for this.
> > > > 
> > > > Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> > > > ---
> > > >   drivers/usb/dwc3/core.c | 113 ++++++++++++++++++++++++++++++++++++++++
> > > >   drivers/usb/dwc3/core.h |  17 +++++-
> > > >   2 files changed, 129 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > > > index 0beaab932e7d..e983aef1fb93 100644
> > > > --- a/drivers/usb/dwc3/core.c
> > > > +++ b/drivers/usb/dwc3/core.c
> > > > @@ -1767,6 +1767,104 @@ static int dwc3_get_clocks(struct dwc3 *dwc)
> > > >       return 0;
> > > >   }
> > > > +/**
> > > > + * dwc3_xhci_find_next_ext_cap - Find the offset of the
> > > > extended capabilities
> > > > + *                    with capability ID id.
> > > > + *
> > > > + * @base:    PCI MMIO registers base address.
> > > > + * @start:    address at which to start looking, (0 or
> > > > HCC_PARAMS to start at
> > > > + *        beginning of list)
> > > > + * @id:        Extended capability ID to search for, or 0 for the next
> > > > + *        capability
> > > > + *
> > > > + * Returns the offset of the next matching extended capability
> > > > structure.
> > > > + * Some capabilities can occur several times, e.g., the
> > > > XHCI_EXT_CAPS_PROTOCOL,
> > > > + * and this provides a way to find them all.
> > > > + */
> > > > +static int dwc3_xhci_find_next_ext_cap(void __iomem *base, u32
> > > > start, int id)
> > > > +{
> > > > +    u32 val;
> > > > +    u32 next;
> > > > +    u32 offset;
> > > > +
> > > > +    offset = start;
> > > > +    if (!start || start == XHCI_HCC_PARAMS_OFFSET) {
> > > > +        val = readl(base + XHCI_HCC_PARAMS_OFFSET);
> > > > +        if (val == ~0)
> > > > +            return 0;
> > > > +        offset = XHCI_HCC_EXT_CAPS(val) << 2;
> > > > +        if (!offset)
> > > > +            return 0;
> > > > +    }
> > > > +    do {
> > > > +        val = readl(base + offset);
> > > > +        if (val == ~0)
> > > > +            return 0;
> > > > +        if (offset != start && (id == 0 ||
> > > > XHCI_EXT_CAPS_ID(val) == id))
> > > > +            return offset;
> > > > +
> > > > +        next = XHCI_EXT_CAPS_NEXT(val);
> > > > +        offset += next << 2;
> > > > +    } while (next);
> > > > +
> > > > +    return 0;
> > > > +}
> > > 
> > > You should not make another copy of xhci_find_next_ext_cap(), but rather
> > > use it directly.
> > > 
> > > We already have drivers outside of usb/host using this function so it
> > > should be fine to do the same for now:
> > > 
> > >     #include "../host/xhci-ext-caps.h"
> > > 
> > Hi Johan,
> > 
> >    This was the approach which we followed when we first introduced the
> > patch [1]. But Thinh suggested to duplicate code so that we can avoid
> > any dependency on xhci (which seems to be right). So since its just one
> > function, I duplicated it here.
> > 
> Hi Thinh,
> 
>   Would like to know your opinion here on how to proceed further.
> 
> Regards,
> Krishna,

Please keep them separated. The xhci-ext-caps.h is for xhci driver only.
It's not meant to be exposed to other drivers. Same with other *.h files
under drivers/usb/host.

Thanks,
Thinh

  reply	other threads:[~2023-05-17  3:22 UTC|newest]

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-14  5:49 [PATCH v8 0/9] Add multiport support for DWC3 controllers Krishna Kurapati
2023-05-14  5:49 ` [PATCH v8 1/9] dt-bindings: usb: qcom,dwc3: Add bindings for SC8280 Multiport Krishna Kurapati
2023-05-14  9:46   ` Krzysztof Kozlowski
2023-05-16 10:59   ` Johan Hovold
2023-05-17 11:10     ` Krishna Kurapati PSSNV
2023-05-17 11:44       ` Johan Hovold
2023-05-17 12:19         ` Krishna Kurapati PSSNV
2023-05-17 12:55           ` Johan Hovold
2023-05-14  5:49 ` [PATCH v8 2/9] dt-bindings: usb: Add bindings for multiport properties on DWC3 controller Krishna Kurapati
2023-05-14  5:49 ` [PATCH v8 3/9] usb: dwc3: core: Access XHCI address space temporarily to read port info Krishna Kurapati
2023-05-15 21:08   ` Bjorn Andersson
2023-05-16  2:12     ` Krishna Kurapati PSSNV
2023-05-16 22:39       ` Thinh Nguyen
2023-05-16 12:11   ` Johan Hovold
2023-05-16 15:02     ` Krishna Kurapati PSSNV
2023-05-17  3:10       ` Krishna Kurapati PSSNV
2023-05-17  3:21         ` Thinh Nguyen [this message]
2023-05-17  7:46           ` Johan Hovold
2023-05-17 23:21             ` Thinh Nguyen
2023-06-07 11:56               ` Johan Hovold
2023-05-17  7:35       ` Johan Hovold
2023-05-17 12:21         ` Krishna Kurapati PSSNV
2023-05-17 15:10           ` Johan Hovold
2023-05-14  5:49 ` [PATCH v8 4/9] usb: dwc3: core: Skip setting event buffers for host only controllers Krishna Kurapati
2023-05-15 21:19   ` Bjorn Andersson
2023-05-16 12:17   ` Johan Hovold
2023-05-16 14:28     ` Krishna Kurapati PSSNV
2023-05-14  5:49 ` [PATCH v8 5/9] usb: dwc3: core: Refactor PHY logic to support Multiport Controller Krishna Kurapati
2023-05-15 21:47   ` Bjorn Andersson
2023-05-16  2:31     ` Krishna Kurapati PSSNV
2023-05-17 16:17   ` Johan Hovold
2023-05-14  5:49 ` [PATCH v8 6/9] usb: dwc3: qcom: Add multiport controller support for qcom wrapper Krishna Kurapati
2023-05-15 22:27   ` Bjorn Andersson
2023-05-16  2:19     ` Krishna Kurapati PSSNV
2023-05-17 16:37       ` Johan Hovold
2023-05-20 17:48         ` Krishna Kurapati PSSNV
2023-06-07 11:37           ` Johan Hovold
2023-06-07 19:51             ` Krishna Kurapati PSSNV
2023-06-08  9:42               ` Johan Hovold
2023-06-08 15:23                 ` Krishna Kurapati PSSNV
2023-06-08 17:57                   ` Thinh Nguyen
2023-06-09  8:18                     ` Johan Hovold
2023-06-09 18:16                       ` Thinh Nguyen
2023-06-15  4:20                         ` Krishna Kurapati PSSNV
2023-06-15 21:08                           ` Thinh Nguyen
2023-06-21  7:38                             ` Johan Hovold
2023-06-22  4:39                               ` Krishna Kurapati PSSNV
2023-06-21  7:34                         ` Johan Hovold
2023-06-22 22:41                           ` Thinh Nguyen
2023-05-26  2:55     ` Bjorn Andersson
2023-05-26 15:25       ` Krishna Kurapati PSSNV
2023-06-07 11:44         ` Johan Hovold
2023-06-07 19:55           ` Krishna Kurapati PSSNV
2023-06-08  9:44             ` Johan Hovold
2023-06-07 12:16   ` Johan Hovold
2023-06-27 15:43     ` Johan Hovold
2023-07-02 19:05       ` Krishna Kurapati PSSNV
2023-07-14  9:00         ` Johan Hovold
2023-07-14 10:38           ` Krishna Kurapati PSSNV
2023-07-21 11:16             ` Johan Hovold
2023-07-21 12:10               ` Konrad Dybcio
2023-07-21 12:54                 ` Johan Hovold
2023-08-11 16:48                   ` Konrad Dybcio
2023-08-12  8:58                     ` Krishna Kurapati PSSNV
2023-05-14  5:49 ` [PATCH v8 7/9] arm64: dts: qcom: sc8280xp: Add multiport controller node for SC8280 Krishna Kurapati
2023-05-15 14:26   ` Johan Hovold
2023-05-15 15:32     ` Krishna Kurapati PSSNV
2023-05-16 10:54       ` Johan Hovold
2023-05-16 14:24         ` Krishna Kurapati PSSNV
2023-05-16 14:42           ` Johan Hovold
2023-05-16 14:44             ` Krishna Kurapati PSSNV
2023-05-14  5:49 ` [PATCH v8 8/9] arm64: dts: qcom: sa8295p: Enable tertiary controller and its 4 USB ports Krishna Kurapati
2023-05-14  5:49 ` [PATCH v8 9/9] arm64: dts: qcom: sa8540-ride: Enable first port of tertiary usb controller Krishna Kurapati
2023-05-15  2:40 ` [PATCH v8 0/9] Add multiport support for DWC3 controllers Bjorn Andersson

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