| Message ID | cover.1487578977.git.baolin.wang@linaro.org |
|---|---|
| Headers | show |
| Series | Introduce usb charger framework to deal with the usb gadget power negotation | expand |
Hi, > -----Original Message----- > From: Baolin Wang [mailto:baolin.wang@linaro.org] > Sent: Tuesday, March 07, 2017 5:39 PM > To: NeilBrown <neilb@suse.com> > Cc: Felipe Balbi <balbi@kernel.org>; Greg KH <gregkh@linuxfoundation.org>; > Sebastian Reichel <sre@kernel.org>; Dmitry Eremin-Solenikov > <dbaryshkov@gmail.com>; David Woodhouse <dwmw2@infradead.org>; > robh@kernel.org; Jun Li <jun.li@nxp.com>; Marek Szyprowski > <m.szyprowski@samsung.com>; Ruslan Bilovol <ruslan.bilovol@gmail.com>; > Peter Chen <peter.chen@freescale.com>; Alan Stern > <stern@rowland.harvard.edu>; grygorii.strashko@ti.com; Yoshihiro Shimoda > <yoshihiro.shimoda.uh@renesas.com>; Lee Jones <lee.jones@linaro.org>; > Mark Brown <broonie@kernel.org>; John Stultz <john.stultz@linaro.org>; > Charles Keepax <ckeepax@opensource.wolfsonmicro.com>; > patches@opensource.wolfsonmicro.com; Linux PM list <linux- > pm@vger.kernel.org>; USB <linux-usb@vger.kernel.org>; device- > mainlining@lists.linuxfoundation.org; LKML <linux-kernel@vger.kernel.org> > 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@suse.com> 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? > > > >> 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? Li Jun > > > >> > >> (2) Change the notifier of usb_phy to be used consistently. > >> Now only 3 phy drivers (phy-generic.c, phy-ab8500-usb.c and > >> phy-gpio-vbus-usb.c) used the notifier of usb_phy. phy-generic.c and > >> phy-gpio-vbus-usb.c were used to send out the connect events, and > >> phy-ab8500-usb.c also was used to send out the MUSB connect events. > >> There are no phy drivers will notify 'vbus_draw' information by the > notifier of usb_phy, which was used consistently now. > >> Moreover it is difficult to change the notifier of usb_phy to be used > >> only to communicate the 'vbus_draw' information, since we need to > >> refactor and test these related phy drivers, power drivers or some > >> mfd drivers, which is a huge workload. > > > > You missed drivers/usb/musb/omap2430.c in you list, but that hardly > > matters. > > But it did not use the notifier of usb_phy. > > > phy-ab8500-usb.c appears to send vbus_draw information. > > Users will not use the vbus_draw information send from phy-ab8500-usb.c > > > > > I understand your reluctance to change drivers that you cannot test. > > An alternative it do change all the > > atomic_notifier_call_chain(.*notifier, > > calls that don't pass a pointer to vbus_draw to pass NULL, and to > > declare the passing of NULL to be deprecated (so hopefully people > > won't use it in new code). > > Then any notification callback that expects a current can just ignore > > calls where the pointer is NULL. > > 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. > > > > > The one difficulty with this is drivers/usb/gadget/udc/pxa27x_udc.c > > It is the only driver which expects a 'gadget', and it doesn't really > > need to as it already knows the gadget. > > The patch below fixes this. > > With that in place, phy-generic and phy-gpio-vbus-usb can be changed > > to pass NULL. When we can safely use the notifier to pass vbus_draw > > information uniformly. > > > >> > >> (3) Still keep charger_type_show() API. > >> Firstly I think we should combine all charger related information > >> into one place for users, which is convenient. > > > > convenience is very much a secondary issue. > > > >> Secondly not only we get charger type from extcon, but also in some > >> scenarios we can get charger type from USB controller driver, USB > >> type-c driver, pmic driver, we should also need one place to export the > charger type. > > > > As I have said, all of these sources of information should feed into > > the extcon. > > > > There are ultimately two possible sources of information about the > > current available from the usb port. > > One is the physical properties of the cable, such as resistance of ID, > > any short between D+ and D- etc. Being properties of the cable, they > > should be reported through the extcon. > > > > The other is information gathered during the USB protocol handshake. > > For USB2, this is the requested current of the profile that the host > > activates. This should be reported though the USB gadget device. > > > > I don't know how USB3 and/or type-C work but I would be surprised if > > they don't fit into the two cases above. If you think otherwise, > > please surprise me. I'm always keen to learn. > > > > If the extcon reports the type of cable detected, and the gadget > > reports the result of any negotiation, then that is enough to > > determine the charger type. It doesn't need to be more convenient than > that. > > If we are all agree we did not need the USB charger, then we can add > 'current' attribute of USB gadget device. > Thanks for your suggestion. > > -- > Baolin.wang > Best Regards
On 9 March 2017 at 18:34, Jun Li <jun.li@nxp.com> wrote: > > >> -----Original Message----- >> From: Baolin Wang [mailto:baolin.wang@linaro.org] >> Sent: Thursday, March 09, 2017 2:11 PM >> To: Jun Li <jun.li@nxp.com> >> Cc: NeilBrown <neilb@suse.com>; Felipe Balbi <balbi@kernel.org>; Greg KH >> <gregkh@linuxfoundation.org>; Sebastian Reichel <sre@kernel.org>; Dmitry >> Eremin-Solenikov <dbaryshkov@gmail.com>; David Woodhouse >> <dwmw2@infradead.org>; robh@kernel.org; Marek Szyprowski >> <m.szyprowski@samsung.com>; Ruslan Bilovol <ruslan.bilovol@gmail.com>; >> Peter Chen <peter.chen@freescale.com>; Alan Stern >> <stern@rowland.harvard.edu>; grygorii.strashko@ti.com; Yoshihiro Shimoda >> <yoshihiro.shimoda.uh@renesas.com>; Lee Jones <lee.jones@linaro.org>; >> Mark Brown <broonie@kernel.org>; John Stultz <john.stultz@linaro.org>; >> Charles Keepax <ckeepax@opensource.wolfsonmicro.com>; >> patches@opensource.wolfsonmicro.com; Linux PM list <linux- >> pm@vger.kernel.org>; USB <linux-usb@vger.kernel.org>; device- >> mainlining@lists.linuxfoundation.org; LKML <linux-kernel@vger.kernel.org> >> 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@nxp.com> wrote: >> > Hi, >> > >> >> -----Original Message----- >> >> From: Baolin Wang [mailto:baolin.wang@linaro.org] >> >> Sent: Tuesday, March 07, 2017 5:39 PM >> >> To: NeilBrown <neilb@suse.com> >> >> Cc: Felipe Balbi <balbi@kernel.org>; Greg KH >> >> <gregkh@linuxfoundation.org>; Sebastian Reichel <sre@kernel.org>; >> >> Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>; David Woodhouse >> >> <dwmw2@infradead.org>; robh@kernel.org; Jun Li <jun.li@nxp.com>; >> >> Marek Szyprowski <m.szyprowski@samsung.com>; Ruslan Bilovol >> >> <ruslan.bilovol@gmail.com>; Peter Chen <peter.chen@freescale.com>; >> >> Alan Stern <stern@rowland.harvard.edu>; grygorii.strashko@ti.com; >> >> Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>; Lee Jones >> >> <lee.jones@linaro.org>; Mark Brown <broonie@kernel.org>; John Stultz >> >> <john.stultz@linaro.org>; Charles Keepax >> >> <ckeepax@opensource.wolfsonmicro.com>; >> >> patches@opensource.wolfsonmicro.com; Linux PM list <linux- >> >> pm@vger.kernel.org>; USB <linux-usb@vger.kernel.org>; device- >> >> mainlining@lists.linuxfoundation.org; LKML >> >> <linux-kernel@vger.kernel.org> >> >> 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@suse.com> 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 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.) >> >> > >> >> >> >> >> >> (2) Change the notifier of usb_phy to be used consistently. >> >> >> Now only 3 phy drivers (phy-generic.c, phy-ab8500-usb.c and >> >> >> phy-gpio-vbus-usb.c) used the notifier of usb_phy. phy-generic.c >> >> >> and phy-gpio-vbus-usb.c were used to send out the connect events, >> >> >> and phy-ab8500-usb.c also was used to send out the MUSB connect >> events. >> >> >> There are no phy drivers will notify 'vbus_draw' information by >> >> >> the >> >> notifier of usb_phy, which was used consistently now. >> >> >> Moreover it is difficult to change the notifier of usb_phy to be >> >> >> used only to communicate the 'vbus_draw' information, since we >> >> >> need to refactor and test these related phy drivers, power drivers >> >> >> or some mfd drivers, which is a huge workload. >> >> > >> >> > You missed drivers/usb/musb/omap2430.c in you list, but that hardly >> >> > matters. >> >> >> >> But it did not use the notifier of usb_phy. >> >> >> >> > phy-ab8500-usb.c appears to send vbus_draw information. >> >> >> >> Users will not use the vbus_draw information send from >> >> phy-ab8500-usb.c >> >> >> >> > >> >> > I understand your reluctance to change drivers that you cannot test. >> >> > An alternative it do change all the >> >> > atomic_notifier_call_chain(.*notifier, >> >> > calls that don't pass a pointer to vbus_draw to pass NULL, and to >> >> > declare the passing of NULL to be deprecated (so hopefully people >> >> > won't use it in new code). >> >> > Then any notification callback that expects a current can just >> >> > ignore calls where the pointer is NULL. >> >> >> >> 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. >> >> >> >> > >> >> > The one difficulty with this is drivers/usb/gadget/udc/pxa27x_udc.c >> >> > It is the only driver which expects a 'gadget', and it doesn't >> >> > really need to as it already knows the gadget. >> >> > The patch below fixes this. >> >> > With that in place, phy-generic and phy-gpio-vbus-usb can be >> >> > changed to pass NULL. When we can safely use the notifier to pass >> >> > vbus_draw information uniformly. >> >> > >> >> >> >> >> >> (3) Still keep charger_type_show() API. >> >> >> Firstly I think we should combine all charger related information >> >> >> into one place for users, which is convenient. >> >> > >> >> > convenience is very much a secondary issue. >> >> > >> >> >> Secondly not only we get charger type from extcon, but also in >> >> >> some scenarios we can get charger type from USB controller driver, >> >> >> USB type-c driver, pmic driver, we should also need one place to >> >> >> export the >> >> charger type. >> >> > >> >> > As I have said, all of these sources of information should feed >> >> > into the extcon. >> >> > >> >> > There are ultimately two possible sources of information about the >> >> > current available from the usb port. >> >> > One is the physical properties of the cable, such as resistance of >> >> > ID, any short between D+ and D- etc. Being properties of the >> >> > cable, they should be reported through the extcon. >> >> > >> >> > The other is information gathered during the USB protocol handshake. >> >> > For USB2, this is the requested current of the profile that the >> >> > host activates. This should be reported though the USB gadget device. >> >> > >> >> > I don't know how USB3 and/or type-C work but I would be surprised >> >> > if they don't fit into the two cases above. If you think >> >> > otherwise, please surprise me. I'm always keen to learn. >> >> > >> >> > If the extcon reports the type of cable detected, and the gadget >> >> > reports the result of any negotiation, then that is enough to >> >> > determine the charger type. It doesn't need to be more convenient >> >> > than >> >> that. >> >> >> >> If we are all agree we did not need the USB charger, then we can add >> >> 'current' attribute of USB gadget device. >> >> Thanks for your suggestion. >> >> >> >> -- >> >> Baolin.wang >> >> Best Regards >> >> >> >> -- >> Baolin.wang >> Best Regards -- Baolin.wang Best Regards
On 10 March 2017 at 16:27, Jun Li <jun.li@nxp.com> wrote: > Hi > >> -----Original Message----- >> From: Baolin Wang [mailto:baolin.wang@linaro.org] >> Sent: Friday, March 10, 2017 3:15 PM >> To: Jun Li <jun.li@nxp.com> >> Cc: NeilBrown <neilb@suse.com>; Felipe Balbi <balbi@kernel.org>; Greg KH >> <gregkh@linuxfoundation.org>; Sebastian Reichel <sre@kernel.org>; Dmitry >> Eremin-Solenikov <dbaryshkov@gmail.com>; David Woodhouse >> <dwmw2@infradead.org>; robh@kernel.org; Marek Szyprowski >> <m.szyprowski@samsung.com>; Ruslan Bilovol <ruslan.bilovol@gmail.com>; >> Peter Chen <peter.chen@freescale.com>; Alan Stern >> <stern@rowland.harvard.edu>; grygorii.strashko@ti.com; Yoshihiro Shimoda >> <yoshihiro.shimoda.uh@renesas.com>; Lee Jones <lee.jones@linaro.org>; >> Mark Brown <broonie@kernel.org>; John Stultz <john.stultz@linaro.org>; >> Charles Keepax <ckeepax@opensource.wolfsonmicro.com>; >> patches@opensource.wolfsonmicro.com; Linux PM list <linux- >> pm@vger.kernel.org>; USB <linux-usb@vger.kernel.org>; device- >> mainlining@lists.linuxfoundation.org; LKML <linux-kernel@vger.kernel.org> >> Subject: Re: [PATCH v19 0/4] Introduce usb charger framework to deal with >> the usb gadget power negotation >> >> On 10 March 2017 at 14:30, Jun Li <jun.li@nxp.com> wrote: >> >> >> > >> >> >> > 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). >> >> That will include these implementation when adding extcon_dev. >> > > OK, thanks. > >> > - If the extcon_dev is directly added in usb_phy/phy, PMIC needs some >> API to findup it. >> >> PMIC can find extcon device by phandle. > > extcon_dev(not a reference pointer) is directly added in usb_phy/phy, not via devicetree, > how PMIC find it by phandle? From my understanding, here we should add one pointer (extcon_dev *), since usb phy is not one external connect device. > >> >> > >> >> 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? >> >> From Neil's suggestion, we only have one place to send out current >> information from usb phy, so I have this concern and doubt if we still need >> the USB charger framework. > > So if put it in phy/usb_phy, this is a problem, that only one place should have > the infor of both speed and usb state, how about put it at usb_gadget, then, > e.g. send the notification in usb_gadget_vbus_connect()? That is same what USB charger did, from this point, we need USB charger to send out vbus draw information according to speed and usb state. But I should listen to other guys suggestion. Peter and Felipe, what do you think? -- Baolin.wang Best Regards
Hi, > -----Original Message----- > From: Baolin Wang [mailto:baolin.wang@linaro.org] > Sent: Monday, March 13, 2017 4:44 PM > To: Jun Li <jun.li@nxp.com> > Cc: NeilBrown <neilb@suse.com>; Felipe Balbi <balbi@kernel.org>; Greg KH > <gregkh@linuxfoundation.org>; Sebastian Reichel <sre@kernel.org>; Dmitry > Eremin-Solenikov <dbaryshkov@gmail.com>; David Woodhouse > <dwmw2@infradead.org>; robh@kernel.org; Marek Szyprowski > <m.szyprowski@samsung.com>; Ruslan Bilovol <ruslan.bilovol@gmail.com>; > Peter Chen <peter.chen@freescale.com>; Alan Stern > <stern@rowland.harvard.edu>; grygorii.strashko@ti.com; Yoshihiro Shimoda > <yoshihiro.shimoda.uh@renesas.com>; Lee Jones <lee.jones@linaro.org>; > Mark Brown <broonie@kernel.org>; John Stultz <john.stultz@linaro.org>; > Charles Keepax <ckeepax@opensource.wolfsonmicro.com>; > patches@opensource.wolfsonmicro.com; Linux PM list <linux- > pm@vger.kernel.org>; USB <linux-usb@vger.kernel.org>; device- > mainlining@lists.linuxfoundation.org; LKML <linux-kernel@vger.kernel.org> > Subject: Re: [PATCH v19 0/4] Introduce usb charger framework to deal with > the usb gadget power negotation > ... ... > >> That is same what USB charger did, from this point, we need USB > >> charger to send out vbus draw information according to speed and usb > >> state. But I should listen to other guys suggestion. Peter and Felipe, what > do you think? Instead of waiting for maintainer's comments on this long discussion, I'd suggest you directly post the patches for the required change, so they can easily know what's the conclusion/solution looks like. Li Jun > > > > So now the only to do work is to find a common place to send the > > notification out (based on gadget speed and sate). > > Yes. > > -- > Baolin.wang > Best Regards
Hi, On 14 March 2017 at 17:57, Lee Jones <lee.jones@linaro.org> wrote: > On Mon, 20 Feb 2017, Baolin Wang wrote: > > [...] > >> drivers/power/supply/wm831x_power.c | 63 +++ >> drivers/usb/gadget/Kconfig | 8 + >> drivers/usb/gadget/udc/Makefile | 1 + >> drivers/usb/gadget/udc/charger.c | 865 +++++++++++++++++++++++++++++++++++ >> drivers/usb/gadget/udc/core.c | 19 +- >> include/linux/usb/charger.h | 176 +++++++ >> include/linux/usb/gadget.h | 3 + >> include/uapi/linux/usb/charger.h | 31 ++ >> 8 files changed, 1165 insertions(+), 1 deletion(-) >> create mode 100644 drivers/usb/gadget/udc/charger.c >> create mode 100644 include/linux/usb/charger.h >> create mode 100644 include/uapi/linux/usb/charger.h > > Why have you sent this set to me? Since you have one ack on patch 4, I think I need CC you. But If you are not interested in this patchset, I will not CC you next time. Sorry. [PATCH v19 4/4] power: wm831x_power: Support USB charger current limit management Integrate with the newly added USB charger interface to limit the current we draw from the USB input based on the input device configuration identified by the USB stack, allowing us to charge more quickly from high current inputs without drawing more current than specified from others. Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Acked-by: Lee Jones <lee.jones@linaro.org> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Acked-by: Peter Chen <peter.chen@freescale.com> Acked-by: Sebastian Reichel <sre@kernel.org> ....... -- Baolin.wang Best Regards
On Tue, 14 Mar 2017, Baolin Wang wrote: > Hi, > > On 14 March 2017 at 17:57, Lee Jones <lee.jones@linaro.org> wrote: > > On Mon, 20 Feb 2017, Baolin Wang wrote: > > > > [...] > > > >> drivers/power/supply/wm831x_power.c | 63 +++ > >> drivers/usb/gadget/Kconfig | 8 + > >> drivers/usb/gadget/udc/Makefile | 1 + > >> drivers/usb/gadget/udc/charger.c | 865 +++++++++++++++++++++++++++++++++++ > >> drivers/usb/gadget/udc/core.c | 19 +- > >> include/linux/usb/charger.h | 176 +++++++ > >> include/linux/usb/gadget.h | 3 + > >> include/uapi/linux/usb/charger.h | 31 ++ > >> 8 files changed, 1165 insertions(+), 1 deletion(-) > >> create mode 100644 drivers/usb/gadget/udc/charger.c > >> create mode 100644 include/linux/usb/charger.h > >> create mode 100644 include/uapi/linux/usb/charger.h > > > > Why have you sent this set to me? > > Since you have one ack on patch 4, I think I need CC you. But If you > are not interested in this patchset, I will not CC you next time. > Sorry. I Acked one of the patches 9 months ago since it contained an MFD change. Yes, if you could drop me from any new submissions, that'd be great, thanks. > [PATCH v19 4/4] power: wm831x_power: Support USB charger current limit > management > > Integrate with the newly added USB charger interface to limit the current > we draw from the USB input based on the input device configuration > identified by the USB stack, allowing us to charge more quickly from high > current inputs without drawing more current than specified from others. > > Signed-off-by: Mark Brown <broonie@kernel.org> > Signed-off-by: Baolin Wang <baolin.wang@linaro.org> > Acked-by: Lee Jones <lee.jones@linaro.org> > Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> > Acked-by: Peter Chen <peter.chen@freescale.com> > Acked-by: Sebastian Reichel <sre@kernel.org> > ....... > -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
On Tue, Mar 07 2017, Baolin Wang wrote: > On 3 March 2017 at 10:23, NeilBrown <neilb@suse.com> wrote: > >> >> I understand your reluctance to change drivers that you cannot test. >> An alternative it do change all the >> atomic_notifier_call_chain(.*notifier, >> calls that don't pass a pointer to vbus_draw to pass NULL, and to >> declare the passing of NULL to be deprecated (so hopefully people won't >> use it in new code). >> Then any notification callback that expects a current can just ignore >> calls where the pointer is NULL. > > 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. When the gadget driver determines that 900mA is available, it calls usb_phy_set_power() which calls the ->set_power() method on the usb_phy. The usb_phy the uses the notifier to inform all interested parties that 900mA is available. NeilBrown
Hi, On 29 March 2017 at 07:04, NeilBrown <neilb@suse.com> wrote: > On Tue, Mar 07 2017, Baolin Wang wrote: > >> On 3 March 2017 at 10:23, NeilBrown <neilb@suse.com> wrote: >> >>> >>> I understand your reluctance to change drivers that you cannot test. >>> An alternative it do change all the >>> atomic_notifier_call_chain(.*notifier, >>> calls that don't pass a pointer to vbus_draw to pass NULL, and to >>> declare the passing of NULL to be deprecated (so hopefully people won't >>> use it in new code). >>> Then any notification callback that expects a current can just ignore >>> calls where the pointer is NULL. >> >> 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. > > When the gadget driver determines that 900mA is available, it calls > usb_phy_set_power() which calls the ->set_power() method on the usb_phy. > The usb_phy the uses the notifier to inform all interested parties > that 900mA is available. That is one possible way. Now we only set vbus draw by usb_gadget_vbus_draw() after setting config and suspend/resume usb device. Maybe we can add one condition in usb_gadget_vbus_draw() like: if (mA >= 500 && gadet->speed >= SUPER_SPEED) mA = 900; -- Baolin.wang Best Regards