On Wed, Jun 08, 2016 at 10:32:19AM +0300, Roger Quadros wrote: > Hi, > > On 24/05/16 05:53, Peter Chen wrote: > > On Mon, May 23, 2016 at 01:36:51PM +0300, Roger Quadros wrote: > >> On 23/05/16 13:34, Jun Li wrote: > >>> Hi > >>> > >>>> -----Original Message----- > >>>> From: Roger Quadros [mailto:rogerq@xxxxxx] > >>>> Sent: Monday, May 23, 2016 6:12 PM > >>>> To: Peter Chen <hzpeterchen@xxxxxxxxx> > >>>> Cc: Jun Li <jun.li@xxxxxxx>; peter.chen@xxxxxxxxxxxxx; balbi@xxxxxxxxxx; > >>>> tony@xxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; dan.j.williams@xxxxxxxxx; > >>>> mathias.nyman@xxxxxxxxxxxxxxx; Joao.Pinto@xxxxxxxxxxxx; > >>>> sergei.shtylyov@xxxxxxxxxxxxxxxxxx; jun.li@xxxxxxxxxxxxx; > >>>> grygorii.strashko@xxxxxx; yoshihiro.shimoda.uh@xxxxxxxxxxx; > >>>> robh@xxxxxxxxxx; nsekhar@xxxxxx; b-liu@xxxxxx; linux-usb@xxxxxxxxxxxxxxx; > >>>> linux-omap@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > >>>> devicetree@xxxxxxxxxxxxxxx > >>>> Subject: Re: [PATCH v8 13/14] usb: gadget: udc: adapt to OTG core > >>>> > >>>> On 23/05/16 06:21, Peter Chen wrote: > >>>>> On Sat, May 21, 2016 at 10:29:40AM +0800, Peter Chen wrote: > >>>>>> On Thu, May 19, 2016 at 10:32:44AM +0300, Roger Quadros wrote: > >>>>>>> On 18/05/16 17:46, Jun Li wrote: > >>>>>>>> > >>>>>>>> > >>>>>>>>>>> > >>>>>>>>>>> I didn't want to have complex Kconfig so decided to have otg as > >>>>>>>>>>> built-in only. > >>>>>>>>>>> What do you want me to change in existing code? and why? > >>>>>>>>>> > >>>>>>>>>> Remove those stuff which only for pass diff driver config Like > >>>>>>>>>> every controller driver need a duplicated > >>>>>>>>>> > >>>>>>>>>> static struct otg_hcd_ops ci_hcd_ops = { > >>>>>>>>>> ... > >>>>>>>>>> } > >>>>>>>>> > >>>>>>>>> This is an exception only. Every controller driver doesn't need to > >>>>>>>>> implement hcd_ops. It is implemented in the hcd core. > >>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> And here is another example, for gadget connect, otg driver can > >>>>>>>>>> directly call to usb_udc_vbus_handler() in drd state machine, but > >>>>>>>>>> you create another interface: > >>>>>>>>>> > >>>>>>>>>> .connect_control = usb_gadget_connect_control, > >>>>>>>>>> > >>>>>>>>>> If the symbol is defined in one driver which is 'm', another > >>>>>>>>>> driver reference it should be 'm' as well, then there is no this > >>>>>>>>>> kind of problem as my understanding. > >>>>>>>>> > >>>>>>>>> That is fine as long as all are 'm'. but how do you solve the case > >>>>>>>>> when Gadget is built in and host is 'm'? OTG has to be built-in > >>>>>>>>> and you will need an hcd to gadget interface. > >>>>>>>> > >>>>>>>> Hcd to gadget interface? Or you want to say otg to host interface? > >>>>>>> > >>>>>>> Sorry, I meant to say host to otg interface. > >>>>>>> > >>>>>>>> > >>>>>>>> I think hcd and gadget are independent each other, now > >>>>>>>> > >>>>>>>> Hcd --> otg; and gadget --> otg, (hcd and gadget use otg's symbol) > >>>>>>> > >>>>>>> It is actually a circular dependency for both. > >>>>>>> hcd <--> otg and gadget <--> otg > >>>>>>> > >>>>>>> hcd -> otg for usb_otg_register/unregister_hcd otg -> hcd for > >>>>>>> usb_add/remove_hcd, usb_bus_start_enum, usb_control_msg, > >>>>>>> usb_hub_find_child > >>>>>>> > >>>>>>> gadget -> otg for usb_otg_register/unregister_gadget > >>>>>>> otg -> gadget for usb_gadget_start/stop, usb_udc_vbus_handler > >>>>>>> > >>>>>>> Now consider what will happen if I get rid of the otg_hcd and > >>>> otg_gadget interfaces. > >>>>>>> 'y' means built-in, 'm' means module. > >>>>>>> > >>>>>>> 1) hcd 'y', gadget 'y' > >>>>>>> otg has to be 'y' for proper build. > >>>>>>> > >>>>>>> 2) hcd 'm', gadget 'm' > >>>>>>> otg has to be 'm' for proper build. > >>>>>>> > >>>>>>> 3) hcd 'y', gadget 'm' > >>>>>>> Build will fail always. > >>>>>>> If otg is 'y', otg build will fail due to dependency on gadget. > >>>>>>> If otg is 'm', hcd build will fail due to dependency on otg. > >>>>>>> > >>>>>>> 4) hcd 'm', gadget 'y' > >>>>>>> Build will fail always. > >>>>>>> If otg is 'y', otg build will fail due to dependency on hcd. > >>>>>>> If otg is 'm', gadget build will fails due to dependency on otg. > >>>>>>> > >>>>>>> So I solve this problem by adding the otg_hcd_ops and otg_gadget_ops > >>>>>>> to remove otg->hcd and otg->gadget dependency. > >>>>>>> > >>>>>>> Now we can address 3) and 4) like so > >>>>>>> > >>>>>>> 3) hcd 'y', gadget 'm' > >>>>>>> otg has to be 'y' for proper build. > >>>>>>> > >>>>>>> 4) hcd 'm', gadget 'y' > >>>>>>> otg has to be 'y' for proper build. > >>>>>>> > >>>>>> > >>>>>> How about this: > >>>>>> Moving usb_otg_register/unregister_hcd to host driver to remove > >>>>>> dependency hcd->otg. And moving usb_otg_get_data to common.c. > >>>>>> > >>>>>> Delete the wait queue at usb-otg.c, and if calling usb_otg_get_data > >>>>>> returns NULL, the host/device driver's probe return -EPROBE_DEFER. > >>>>>> When the otg driver is probed successfully, the host/device will be > >>>>>> re-probed again, and usb_otg_register_hcd will be called again. > >>>>>> > >>>>>> And let OTG depends on HCD && GADGET, and delete otg_hcd_ops and > >>>>>> otg_gadget_ops. Below build dependency issues can be fixed. > >>>>>> What do you think? > >>>>>> > >>>>>>> 1) hcd 'y', gadget 'y' > >>>>>>> otg has to be 'y' for proper build. > >>>>>>> > >>>>>>> 2) hcd 'm', gadget 'm' > >>>>>>> otg has to be 'm' for proper build. > >>>>>>> > >>>>>>> 3) hcd 'y', gadget 'm' > >>>>>>> Build will fail always. > >>>>>>> If otg is 'y', otg build will fail due to dependency on gadget. > >>>>>>> If otg is 'm', hcd build will fail due to dependency on otg. > >>>>>>> > >>>>>>> 4) hcd 'm', gadget 'y' > >>>>>>> Build will fail always. > >>>>>>> If otg is 'y', otg build will fail due to dependency on hcd. > >>>>>>> If otg is 'm', gadget build will fails due to dependency on otg. > >>>>>> -- > >>>>>> > >>>>> > >>>>> After thinking more, my suggestion can't work. How about moving > >>>>> CONFIG_USB_OTG out of CONFIG_USB, in that case, CONFIG_USB_OTG can > >>>>> only be built in. > >>>>> > >>>> I tried this but it still doesn't resolve 3 and 4. I.e. > >>>> it can't be automatically set to 'y' when either of hcd/gadget is 'y' > >>>> and the other is 'm'. > >>> > >>> USB_OTG only can be selected by *user*, can't be automatically set to > >>> 'y' like you said, no matter what's hcd/gadget config, USB_OTG can be > >>> disabled in any cases. > >> > >> Yes. I am on the same page with that. > >>> > >>> I think Peter's intention is to make USB_OTG to be 'bool', either disabled; > >>> or built-in(if enabled), something like your original idea? > >> > >> I'm fine with my original idea if you guys can confirm :). > >> > > > > Please do it. > > > > OK. I managed to fix this and get usbotg to be as module when both USB and GADGET > are modules with the following patch. > > What we do is use USB_OTG_CORE as a hidden tristate symbol that is used to build usbotg.o > only if USB_OTG is enabled. > > USB_OTG is used to enable/disable OTG and it has to be bool since it is used at mutiple > places in the code. > I am ok with that, but better you can write down above at your commit log, then the reader can know your design purpose. Peter > cheers, > -roger > > --- > > diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig > index 8689dcb..ed596ec 100644 > --- a/drivers/usb/Kconfig > +++ b/drivers/usb/Kconfig > @@ -32,6 +32,23 @@ if USB_SUPPORT > config USB_COMMON > tristate > > +config USB_OTG_CORE > + tristate > + > +config USB_OTG > + bool "OTG/Dual-role support" > + depends on PM && USB && USB_GADGET > + default n > + ---help--- > + The most notable feature of USB OTG is support for a > + "Dual-Role" device, which can act as either a device > + or a host. The initial role is decided by the type of > + plug inserted and can be changed later when two dual > + role devices talk to each other. > + > + Select this only if your board has Mini-AB/Micro-AB > + connector. > + > config USB_ARCH_HAS_HCD > def_bool y > > @@ -40,6 +57,7 @@ config USB > tristate "Support for Host-side USB" > depends on USB_ARCH_HAS_HCD > select USB_COMMON > + select USB_OTG_CORE > select NLS # for UTF-8 strings > ---help--- > Universal Serial Bus (USB) is a specification for a serial bus > diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile > index 16a5b55..03f7204 100644 > --- a/drivers/usb/Makefile > +++ b/drivers/usb/Makefile > @@ -59,6 +59,6 @@ obj-$(CONFIG_USB_RENESAS_USBHS) += renesas_usbhs/ > obj-$(CONFIG_USB_GADGET) += gadget/ > > obj-$(CONFIG_USB_COMMON) += common/ > -obj-$(CONFIG_USB_OTG) += common/ > +obj-$(CONFIG_USB_OTG_CORE) += common/ > > obj-$(CONFIG_USBIP_CORE) += usbip/ > diff --git a/drivers/usb/common/Makefile b/drivers/usb/common/Makefile > index 730d928..5122b3f 100644 > --- a/drivers/usb/common/Makefile > +++ b/drivers/usb/common/Makefile > @@ -7,5 +7,7 @@ usb-common-y += common.o > usb-common-$(CONFIG_USB_LED_TRIG) += led.o > > obj-$(CONFIG_USB_ULPI_BUS) += ulpi.o > +ifeq ($(CONFIG_USB_OTG),y) > usbotg-y := usb-otg.o usb-otg-fsm.o > -obj-$(CONFIG_USB_OTG) += usbotg.o > +obj-$(CONFIG_USB_OTG_CORE) += usbotg.o > +endif > diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c > index f5eb7f5..98fcfa2 100644 > --- a/drivers/usb/common/usb-otg.c > +++ b/drivers/usb/common/usb-otg.c > @@ -16,6 +16,7 @@ > > #include <linux/kernel.h> > #include <linux/list.h> > +#include <linux/module.h> > #include <linux/of.h> > #include <linux/of_platform.h> > #include <linux/usb/of.h> > @@ -841,3 +842,5 @@ int usb_otg_gadget_ready(struct usb_gadget *gadget, bool ready) > return 0; > } > EXPORT_SYMBOL_GPL(usb_otg_gadget_ready); > + > +MODULE_LICENSE("GPL"); > diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig > index de371e6..37f8c54 100644 > --- a/drivers/usb/core/Kconfig > +++ b/drivers/usb/core/Kconfig > @@ -41,20 +41,6 @@ config USB_DYNAMIC_MINORS > > If you are unsure about this, say N here. > > -config USB_OTG > - bool "OTG/Dual-role support" > - depends on PM && USB_GADGET > - default n > - help > - The most notable feature of USB OTG is support for a > - "Dual-Role" device, which can act as either a device > - or a host. The initial role is decided by the type of > - plug inserted and can be changed later when two dual > - role devices talk to each other. > - > - Select this only if your board has Mini-AB/Micro-AB > - connector. > - > config USB_OTG_WHITELIST > bool "Rely on OTG and EH Targeted Peripherals List" > depends on USB > diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig > index 2057add..9d55384 100644 > --- a/drivers/usb/gadget/Kconfig > +++ b/drivers/usb/gadget/Kconfig > @@ -16,6 +16,7 @@ > menuconfig USB_GADGET > tristate "USB Gadget Support" > select USB_COMMON > + select USB_OTG_CORE > select NLS > help > USB is a master/slave protocol, organized with one master > -- > 2.7.4 > > > -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
