From: Peter Chen <hzpeterchen@gmail.com>
To: Roger Quadros <rogerq@ti.com>
Cc: peter.chen@freescale.com, balbi@kernel.org, tony@atomide.com,
gregkh@linuxfoundation.org, dan.j.williams@intel.com,
mathias.nyman@linux.intel.com, Joao.Pinto@synopsys.com,
sergei.shtylyov@cogentembedded.com, jun.li@freescale.com,
grygorii.strashko@ti.com, yoshihiro.shimoda.uh@renesas.com,
robh@kernel.org, nsekhar@ti.com, b-liu@ti.com,
linux-usb@vger.kernel.org, linux-omap@vger.kernel.org,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCH v8 13/14] usb: gadget: udc: adapt to OTG core
Date: Sat, 21 May 2016 10:44:47 +0800 [thread overview]
Message-ID: <20160521024447.GB15088@shlinux2> (raw)
In-Reply-To: <573EBC0B.7030204@ti.com>
On Fri, May 20, 2016 at 10:26:03AM +0300, Roger Quadros wrote:
> Peter,
>
> On 20/05/16 04:39, Peter Chen wrote:
> > On Wed, May 18, 2016 at 03:45:11PM +0300, Roger Quadros wrote:
> >> On 18/05/16 06:18, Peter Chen wrote:
> >>> On Mon, May 16, 2016 at 12:51:53PM +0300, Roger Quadros wrote:
> >>>> On 16/05/16 12:23, Peter Chen wrote:
> >>>>> On Mon, May 16, 2016 at 11:26:57AM +0300, Roger Quadros wrote:
> >>>>>> Hi,
> >>>>>>
> >>>>>> On 16/05/16 10:02, Peter Chen wrote:
> >>>>>>> On Fri, May 13, 2016 at 01:03:27PM +0300, Roger Quadros wrote:
> >>>>>>>> +
> >>>>>>>> +static int usb_gadget_connect_control(struct usb_gadget *gadget, bool connect)
> >>>>>>>> +{
> >>>>>>>> + struct usb_udc *udc;
> >>>>>>>> +
> >>>>>>>> + mutex_lock(&udc_lock);
> >>>>>>>> + udc = usb_gadget_to_udc(gadget);
> >>>>>>>> + if (!udc) {
> >>>>>>>> + dev_err(gadget->dev.parent, "%s: gadget not registered.\n",
> >>>>>>>> + __func__);
> >>>>>>>> + mutex_unlock(&udc_lock);
> >>>>>>>> + return -EINVAL;
> >>>>>>>> + }
> >>>>>>>> +
> >>>>>>>> + if (connect) {
> >>>>>>>> + if (!gadget->connected)
> >>>>>>>> + usb_gadget_connect(udc->gadget);
> >>>>>>>> + } else {
> >>>>>>>> + if (gadget->connected) {
> >>>>>>>> + usb_gadget_disconnect(udc->gadget);
> >>>>>>>> + udc->driver->disconnect(udc->gadget);
> >>>>>>>> + }
> >>>>>>>> + }
> >>>>>>>> +
> >>>>>>>> + mutex_unlock(&udc_lock);
> >>>>>>>> +
> >>>>>>>> + return 0;
> >>>>>>>> +}
> >>>>>>>> +
> >>>>>>>
> >>>>>>> Since this is called for vbus interrupt, why not using
> >>>>>>> usb_udc_vbus_handler directly, and call udc->driver->disconnect
> >>>>>>> at usb_gadget_stop.
> >>>>>>
> >>>>>> We can't assume that this is always called for vbus interrupt so
> >>>>>> I decided not to call usb_udc_vbus_handler.
> >>>>>>
> >>>>>> udc->vbus is really pointless for us. We keep vbus states in our
> >>>>>> state machine and leave udc->vbus as ture always.
> >>>>>>
> >>>>>> Why do you want to move udc->driver->disconnect() to stop?
> >>>>>> If USB controller disconnected from bus then the gadget driver
> >>>>>> must be notified about the disconnect immediately. The controller
> >>>>>> may or may not be stopped by the core.
> >>>>>>
> >>>>>
> >>>>> Then, would you give some comments when this API will be used?
> >>>>> I was assumed it is only used for drd state machine.
> >>>>
> >>>> drd_state machine didn't even need this API in the first place :).
> >>>> You guys wanted me to separate out start/stop and connect/disconnect for full OTG case.
> >>>> Won't full OTG state machine want to use this API? If not what would it use?
> >>>>
> >>>
> >>> Oh, I meant only drd and fully otg state machine needs it. I am
> >>> wondering if we need have a new API to do it. Two questions:
> >>
> >> OK.
> >>>
> >>> - Except for vbus interrupt, any chances this API will be used at
> >>> current logic?
> >>
> >> I don't think so. But we can't assume caller behaviour for any API.
> >>
> >>> - When this API is called but without a coming gadget->stop?
> >>>
> >> Never for DRD case. But we want to catch wrong users.
> >>
> >
> > In future, otg_start_gadget will be used for both DRD and fully OTG FSM.
> > There is no otg_loc_conn at current DRD FSM, but there is
> > otg_loc_conn at current OTG FSM, see below.
> >
> > DRD FSM:
> > case OTG_STATE_B_IDLE:
> > drd_set_protocol(fsm, PROTO_UNDEF);
> > otg_drv_vbus(otg, 0);
> > break;
> > case OTG_STATE_B_PERIPHERAL:
> > drd_set_protocol(fsm, PROTO_GADGET);
> > otg_drv_vbus(otg, 0);
> > break;
> >
> > OTG FSM:
> > case OTG_STATE_B_IDLE:
> > otg_drv_vbus(otg, 0);
> > otg_chrg_vbus(otg, 0);
> > otg_loc_conn(otg, 0);
> > otg_loc_sof(otg, 0);
> > /*
> > * Driver is responsible for starting ADP probing
> > * if ADP sensing times out.
> > */
> > otg_start_adp_sns(otg);
> > otg_set_protocol(fsm, PROTO_UNDEF);
> > otg_add_timer(otg, B_SE0_SRP);
> > break;
> > case OTG_STATE_B_PERIPHERAL:
> > otg_chrg_vbus(otg, 0);
> > otg_loc_sof(otg, 0);
> > otg_set_protocol(fsm, PROTO_GADGET);
> > otg_loc_conn(otg, 1);
> > break;
> >
> > My original suggestion is to have an API to do pull dp and this API
> > will be used at both DRD and OTG FSM, and called at otg_loc_conn.
>
> The API is usb_gadget_connect_control();
>
> > The (de)initialize is the same for both two FSMs, it both includes
> > init peripheral mode and pull up dp, and can be done by drd_set_protocol(fsm, PROTO_GADGET)
> > otg_loc_conn(otg, 1);
> >
> > What do you think?
> >
>
> I think loc_conn is a bit confusing to drd users. Another issue I see is that
> DRD controller drivers will need to explicitly pass .loc_conn ops via the otg_fsm_ops.
> This is an additional step and totally unnecessary as it can be automatically done
> via direct DRD -> UDC-core call.
>
If you are stick to that, let's follow your way if Felipe agree with it
too, although it lets the DRD state machine look different with OTG's.
--
Best Regards,
Peter Chen
next prev parent reply other threads:[~2016-05-21 2:49 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-13 10:03 [PATCH v8 00/14] USB OTG/dual-role framework Roger Quadros
2016-05-13 10:03 ` [PATCH v8 01/14] usb: hcd: Initialize hcd->flags to 0 Roger Quadros
2016-05-13 10:03 ` [PATCH v8 02/14] usb: otg-fsm: Prevent build warning "VDBG" redefined Roger Quadros
2016-05-13 10:03 ` [PATCH v8 03/14] usb: hcd.h: Add OTG to HCD interface Roger Quadros
2016-05-13 10:03 ` [PATCH v8 04/14] usb: otg-fsm: use usb_otg wherever possible Roger Quadros
2016-05-13 10:03 ` [PATCH v8 05/14] usb: otg-fsm: move host controller operations into usb_otg->hcd_ops Roger Quadros
2016-05-13 10:03 ` [PATCH v8 06/14] usb: gadget.h: Add OTG to gadget interface Roger Quadros
2016-05-13 10:03 ` [PATCH v8 07/14] usb: otg: get rid of CONFIG_USB_OTG_FSM in favour of CONFIG_USB_OTG Roger Quadros
2016-05-13 10:03 ` [PATCH v8 08/14] usb: otg: add OTG/dual-role core Roger Quadros
2016-05-16 9:00 ` Roger Quadros
[not found] ` <CAL411-qb0dHQrn+AarSApCq6L=toKPRerLKDcx_H+5WDWu_VDg@mail.gmail.com>
2016-05-18 12:59 ` Roger Quadros
2016-05-20 8:31 ` Roger Quadros
2016-05-20 9:19 ` Roger Quadros
2016-05-20 9:53 ` Peter Chen
2016-05-23 10:06 ` Roger Quadros
2016-05-24 9:45 ` Roger Quadros
2016-05-25 2:44 ` Peter Chen
2016-05-25 3:19 ` Jun Li
2016-05-25 12:26 ` Roger Quadros
2016-05-25 12:21 ` Roger Quadros
2016-05-25 14:44 ` Jun Li
2016-05-13 10:03 ` [PATCH v8 09/14] usb: of: add an API to get OTG device from USB controller node Roger Quadros
2016-05-20 9:29 ` [PATCH v9 " Roger Quadros
2016-05-23 21:06 ` Rob Herring
2016-05-13 10:03 ` [PATCH v8 10/14] usb: otg: add hcd companion support Roger Quadros
2016-05-13 18:13 ` Rob Herring
2016-05-16 8:12 ` Roger Quadros
2016-05-20 9:32 ` [PATCH v9 " Roger Quadros
2016-05-23 21:07 ` Rob Herring
2016-05-13 10:03 ` [PATCH v8 11/14] usb: otg: use dev_dbg() instead of VDBG() Roger Quadros
2016-05-13 10:03 ` [PATCH v8 12/14] usb: hcd: Adapt to OTG core Roger Quadros
2016-05-13 10:03 ` [PATCH v8 13/14] usb: gadget: udc: adapt " Roger Quadros
2016-05-16 7:02 ` Peter Chen
2016-05-16 8:26 ` Roger Quadros
2016-05-16 9:23 ` Peter Chen
2016-05-16 9:51 ` Roger Quadros
2016-05-17 7:38 ` Jun Li
2016-05-17 8:08 ` Roger Quadros
2016-05-17 8:28 ` Jun Li
2016-05-18 12:42 ` Roger Quadros
2016-05-18 13:12 ` Jun Li
2016-05-18 13:43 ` Roger Quadros
2016-05-18 14:46 ` Jun Li
2016-05-19 7:32 ` Roger Quadros
2016-05-21 2:29 ` Peter Chen
2016-05-23 3:21 ` Peter Chen
2016-05-23 10:11 ` Roger Quadros
2016-05-23 10:34 ` Jun Li
2016-05-23 10:36 ` Roger Quadros
2016-05-24 2:53 ` Peter Chen
2016-06-08 7:32 ` Roger Quadros
2016-06-08 9:05 ` Peter Chen
2016-05-18 3:18 ` Peter Chen
2016-05-18 12:45 ` Roger Quadros
2016-05-20 1:39 ` Peter Chen
2016-05-20 7:26 ` Roger Quadros
2016-05-21 2:44 ` Peter Chen [this message]
2016-06-01 7:38 ` Peter Chen
2016-06-02 11:07 ` Roger Quadros
2016-05-13 10:03 ` [PATCH v8 14/14] usb: host: xhci-plat: Add otg device to platform data Roger Quadros
2016-05-30 9:29 ` [PATCH v8 00/14] USB OTG/dual-role framework Peter Chen
2016-05-30 14:04 ` Roger Quadros
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160521024447.GB15088@shlinux2 \
--to=hzpeterchen@gmail.com \
--cc=Joao.Pinto@synopsys.com \
--cc=b-liu@ti.com \
--cc=balbi@kernel.org \
--cc=dan.j.williams@intel.com \
--cc=devicetree@vger.kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=grygorii.strashko@ti.com \
--cc=jun.li@freescale.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=mathias.nyman@linux.intel.com \
--cc=nsekhar@ti.com \
--cc=peter.chen@freescale.com \
--cc=robh@kernel.org \
--cc=rogerq@ti.com \
--cc=sergei.shtylyov@cogentembedded.com \
--cc=tony@atomide.com \
--cc=yoshihiro.shimoda.uh@renesas.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).