> -----Original Message----- > From: Baolin Wang [mailto:baolin.wang@xxxxxxxxxx] > Sent: Thursday, March 09, 2017 7:23 PM > To: Jun Li <jun.li@xxxxxxx> > Cc: NeilBrown <neilb@xxxxxxxx>; Felipe Balbi <balbi@xxxxxxxxxx>; Greg KH > <gregkh@xxxxxxxxxxxxxxxxxxx>; Sebastian Reichel <sre@xxxxxxxxxx>; Dmitry > Eremin-Solenikov <dbaryshkov@xxxxxxxxx>; David Woodhouse > <dwmw2@xxxxxxxxxxxxx>; robh@xxxxxxxxxx; Marek Szyprowski > <m.szyprowski@xxxxxxxxxxx>; Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>; > Peter Chen <peter.chen@xxxxxxxxxxxxx>; Alan Stern > <stern@xxxxxxxxxxxxxxxxxxx>; grygorii.strashko@xxxxxx; Yoshihiro Shimoda > <yoshihiro.shimoda.uh@xxxxxxxxxxx>; Lee Jones <lee.jones@xxxxxxxxxx>; > Mark Brown <broonie@xxxxxxxxxx>; John Stultz <john.stultz@xxxxxxxxxx>; > Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>; > patches@xxxxxxxxxxxxxxxxxxxxxxxxxxx; Linux PM list <linux- > pm@xxxxxxxxxxxxxxx>; USB <linux-usb@xxxxxxxxxxxxxxx>; device- > mainlining@xxxxxxxxxxxxxxxxxxxxxxxxx; LKML <linux-kernel@xxxxxxxxxxxxxxx> > Subject: Re: [PATCH v19 0/4] Introduce usb charger framework to deal with > the usb gadget power negotation > > On 9 March 2017 at 18:34, Jun Li <jun.li@xxxxxxx> wrote: > > > > > >> -----Original Message----- > >> From: Baolin Wang [mailto:baolin.wang@xxxxxxxxxx] > >> Sent: Thursday, March 09, 2017 2:11 PM > >> To: Jun Li <jun.li@xxxxxxx> > >> Cc: NeilBrown <neilb@xxxxxxxx>; Felipe Balbi <balbi@xxxxxxxxxx>; Greg > >> KH <gregkh@xxxxxxxxxxxxxxxxxxx>; Sebastian Reichel <sre@xxxxxxxxxx>; > >> Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>; David Woodhouse > >> <dwmw2@xxxxxxxxxxxxx>; robh@xxxxxxxxxx; Marek Szyprowski > >> <m.szyprowski@xxxxxxxxxxx>; Ruslan Bilovol > >> <ruslan.bilovol@xxxxxxxxx>; Peter Chen <peter.chen@xxxxxxxxxxxxx>; > >> Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>; grygorii.strashko@xxxxxx; > >> Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>; Lee Jones > >> <lee.jones@xxxxxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>; John Stultz > >> <john.stultz@xxxxxxxxxx>; Charles Keepax > >> <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>; > >> patches@xxxxxxxxxxxxxxxxxxxxxxxxxxx; Linux PM list <linux- > >> pm@xxxxxxxxxxxxxxx>; USB <linux-usb@xxxxxxxxxxxxxxx>; device- > >> mainlining@xxxxxxxxxxxxxxxxxxxxxxxxx; LKML > >> <linux-kernel@xxxxxxxxxxxxxxx> > >> Subject: Re: [PATCH v19 0/4] Introduce usb charger framework to deal > >> with the usb gadget power negotation > >> > >> Hi, > >> > >> On 9 March 2017 at 09:50, Jun Li <jun.li@xxxxxxx> wrote: > >> > Hi, > >> > > >> >> -----Original Message----- > >> >> From: Baolin Wang [mailto:baolin.wang@xxxxxxxxxx] > >> >> Sent: Tuesday, March 07, 2017 5:39 PM > >> >> To: NeilBrown <neilb@xxxxxxxx> > >> >> Cc: Felipe Balbi <balbi@xxxxxxxxxx>; Greg KH > >> >> <gregkh@xxxxxxxxxxxxxxxxxxx>; Sebastian Reichel <sre@xxxxxxxxxx>; > >> >> Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>; David > Woodhouse > >> >> <dwmw2@xxxxxxxxxxxxx>; robh@xxxxxxxxxx; Jun Li <jun.li@xxxxxxx>; > >> >> Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>; Ruslan Bilovol > >> >> <ruslan.bilovol@xxxxxxxxx>; Peter Chen > <peter.chen@xxxxxxxxxxxxx>; > >> >> Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>; grygorii.strashko@xxxxxx; > >> >> Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>; Lee Jones > >> >> <lee.jones@xxxxxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>; John > >> >> Stultz <john.stultz@xxxxxxxxxx>; Charles Keepax > >> >> <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>; > >> >> patches@xxxxxxxxxxxxxxxxxxxxxxxxxxx; Linux PM list <linux- > >> >> pm@xxxxxxxxxxxxxxx>; USB <linux-usb@xxxxxxxxxxxxxxx>; device- > >> >> mainlining@xxxxxxxxxxxxxxxxxxxxxxxxx; LKML > >> >> <linux-kernel@xxxxxxxxxxxxxxx> > >> >> Subject: Re: [PATCH v19 0/4] Introduce usb charger framework to > >> >> deal with the usb gadget power negotation > >> >> > >> >> On 3 March 2017 at 10:23, NeilBrown <neilb@xxxxxxxx> wrote: > >> >> > On Mon, Feb 20 2017, Baolin Wang wrote: > >> >> > > >> >> >> Currently the Linux kernel does not provide any standard > >> >> >> integration of this feature that integrates the USB subsystem > >> >> >> with the system power regulation provided by PMICs meaning that > >> >> >> either vendors must add this in their kernels or USB gadget > >> >> >> devices based on Linux (such as mobile phones) may not behave as > they should. > >> >> >> Thus provide a > >> >> standard framework for doing this in kernel. > >> >> >> > >> >> >> Now introduce one user with wm831x_power to support and test > >> >> >> the usb > >> >> charger. > >> >> >> Another user introduced to support charger detection by Jun Li: > >> >> >> https://www.spinics.net/lists/linux-usb/msg139425.html > >> >> >> Moreover there may be other potential users will use it in future. > >> >> >> > >> >> >> 1. Before v19 patchset we've fixed below issues in extcon > >> >> >> subsystem and usb phy driver, now all were merged. (Thanks for > >> >> >> Neil's > >> >> >> suggestion) > >> >> >> (1) Have fixed the inconsistencies with USB connector types in > >> >> >> extcon subsystem by following links: > >> >> >> https://lkml.org/lkml/2016/12/21/13 > >> >> >> https://lkml.org/lkml/2016/12/21/15 > >> >> >> https://lkml.org/lkml/2016/12/21/79 > >> >> >> https://lkml.org/lkml/2017/1/3/13 > >> >> >> > >> >> >> (2) Instead of using 'set_power' callback in phy drivers, we > >> >> >> will introduce USB charger to set PMIC current drawn from USB > >> >> >> configuration, moreover some 'set_power' callbacks did not > >> >> >> implement anything to set PMIC current, thus remove them by > >> following links: > >> >> >> https://lkml.org/lkml/2017/1/18/436 > >> >> >> https://lkml.org/lkml/2017/1/18/439 > >> >> >> https://lkml.org/lkml/2017/1/18/438 > >> >> >> Now only two phy drivers (phy-isp1301-omap.c and > >> >> >> phy-gpio-vbus-usb.c) still used 'set_power' callback to set > >> >> >> current, we can remove them in future. (I have no platform with > >> >> >> enabling these two phy drivers, so I can not test them if I > >> >> >> converted 'set_power' callback to USB > >> >> >> charger.) > >> >> >> > >> >> >> 2. Some issues pointed by Neil Brown were sill kept in this v19 > >> >> >> patchset, and I expalined each issue and may be need discuss again: > >> >> >> (1) Change all usb phys to register an extcon and to send > >> >> >> appropriate > >> >> notifications. > >> >> >> Firstly, now only 3 USB phy drivers (phy-qcom-8x16-usb.c, > >> >> >> phy-omap-otg.c and > >> >> >> phy-msm-usb.c) had registered an extcon, mostly did not. I can > >> >> >> not change all usb phys to register an extcon, since there are > >> >> >> no extcon device to register for these different phy drivers. > >> >> > > >> >> > You don't have to change every driver. You just need to make it > >> >> > easy and obvious how to change drivers in a consistent coherent way. > >> >> > For a start you would add a 'struct extcon_dev' to 'struct > >> >> > usb_phy', and possibly add or extend some 'static inline's in > >> >> > linux/usb/phy.h to send notification on that extcon (if it is non-NULL). > >> >> > e.g. usb_phy_vbus_on() could send an extcon notification. > >> >> > > >> >> > Then any phy driver which adds support for setting > >> >> > phy->extcon_dev appropriately, immediately gets the relevant > notifications sent. > >> >> > >> >> OK. We can make these extcon related code into phy common part. > >> >> > >> > > >> > Will generic phy need add extcon as well? > >> > >> Yes, will add a 'struct extcon_dev*' in 'struct usb_phy', which will > >> be common code. > >> > > > > I mean the common code need add 'struct extcon_dev' into both 'struct > > phy' and 'struct usb_phy', right? as some/new usb phy use that generic phy > driver. > > Ah, you remind me. Seems we need also add one 'struct extcon_dev' into > 'struct phy'. > > >> > > >> >> > > >> >> >> Secondly, I also agreed with Peter's comments: Not only USB PHY > >> >> >> to register an extcon, but also for the drivers which can > >> >> >> detect USB charger type, it may be USB controller driver, USB > >> >> >> type-c driver, pmic driver, and these drivers may not have an > >> >> >> extcon device since the internal part can finish the vbus detect. > >> >> > > >> >> > Whichever part can detect vbus, the driver for that part must be > >> >> > able to find the extcon and trigger a notification. > >> >> > Maybe one part can detect VBUS, another can measure the > >> >> > resistance on ID and a third can work through the state machine > >> >> > to determine if D+ and D- are shorted together. > >> >> > Somehow these three need to work together to determine what is > >> >> plugged > >> >> > in to the external connection port. Somewhere there much an > 'extcon' > >> >> > device which represents that port and which the three devices > >> >> > can find and can interact with. > >> >> > I think it makes sense for the usb_phy to be the connection point. > >> >> > Each of the devices can get to the phy, and the phy can get to > >> >> > the > >> extcon. > >> >> > It doesn't matter very much if the usb phy driver creates the > >> >> > extcon, or if something else creates the extcon and the phy > >> >> > driver performs a lookup to find it (e.g. based on devicetree info). > >> >> > > >> >> > The point is that there is obviously an external physical > >> >> > connection, and so there should be an 'extcon' device that > represents it. > >> >> > >> >> Peter & Jun, is it OK for you every phy has one extcon device to > >> >> receive VBUS notification, especially for detecting the charger > >> >> type by > >> software? > >> >> > >> > > >> > My understanding is phy/usb_phy as the connection point, will send > >> > the notification to PMIC driver which actually control the charge > >> > current, also this will be done in your common framework, right? > >> > >> Not in USB charger framework. If we are all agree every usb_phy can > >> register one extcon device, can get correct charger type and send out > >> correct vbus_draw information, then we don't need USB charger > >> framework as Neil suggested. So this will be okay for your case > >> (especially for detecting the charger type by software) ? > > > > In my case, charger detection is done by controller driver and I need > > do charger type detection internally, and only pass the current draw > > info via phy which will send out, this seems ok for me, but I think it > > will be good if you or someone can show us an example user based on the > design Neil suggested. > > Will you work out that common code if this USB charger framework is not > needed? > > I will add a 'struct extcon_dev*' in 'struct usb_phy' and struct phy“. Others > are already ready if everyone has no complain about current design, except Only adding extcon_dev into usb_phy/phy and all others are ready? My understanding you will also do: - We need find a central place to send the notification(phy common part). - If the extcon_dev is directly added in usb_phy/phy, PMIC needs some API to findup it. > my one concern. (I am afraid if it is enough to send out vbus draw > information from USB phy driver, for example you will miss super speed > (900mA), which need get the speed information from gadget driver.) > Can we handle this in USB(so has super speed information) and just send out 900mA directly? Li Jun ��.n��������+%������w��{.n�����{���)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
