[balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[kbuild test robot]

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
head:   89fe2b5ab11cdf6a67d4492d893e70e330aa7060
commit: 231b31ca34485552fe27e67dc6d30d06079c7648 [64/67] usb: gadget: move gadget API functions to udc-core
config: x86_64-randconfig-s1-06061834 (attached as .config)
compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
reproduce:
        git checkout 231b31ca34485552fe27e67dc6d30d06079c7648
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   drivers/built-in.o: In function `nop_set_peripheral':
>> phy-generic.c:(.text+0x14423f): undefined reference to `usb_gadget_vbus_connect'
   drivers/built-in.o: In function `nop_gpio_vbus_thread':
>> phy-generic.c:(.text+0x144742): undefined reference to `usb_gadget_vbus_disconnect'

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Felipe Balbi]

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Hi,

kbuild test robot <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
> head:   89fe2b5ab11cdf6a67d4492d893e70e330aa7060
> commit: 231b31ca34485552fe27e67dc6d30d06079c7648 [64/67] usb: gadget: move gadget API functions to udc-core
> config: x86_64-randconfig-s1-06061834 (attached as .config)
> compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
> reproduce:
>         git checkout 231b31ca34485552fe27e67dc6d30d06079c7648
>         # save the attached .config to linux build tree
>         make ARCH=x86_64 
>
> All errors (new ones prefixed by >>):
>
>    drivers/built-in.o: In function `nop_set_peripheral':
>>> phy-generic.c:(.text+0x14423f): undefined reference to `usb_gadget_vbus_connect'
>    drivers/built-in.o: In function `nop_gpio_vbus_thread':
>>> phy-generic.c:(.text+0x144742): undefined reference to `usb_gadget_vbus_disconnect'

oh yeah, I have to fix this. I'll do it now.

-- 
balbi

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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Felipe Balbi]

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Hi,

Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> writes:
> [ Unknown signature status ]
>
> Hi,
>
> kbuild test robot <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:
>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
>> head:   89fe2b5ab11cdf6a67d4492d893e70e330aa7060
>> commit: 231b31ca34485552fe27e67dc6d30d06079c7648 [64/67] usb: gadget: move gadget API functions to udc-core
>> config: x86_64-randconfig-s1-06061834 (attached as .config)
>> compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
>> reproduce:
>>         git checkout 231b31ca34485552fe27e67dc6d30d06079c7648
>>         # save the attached .config to linux build tree
>>         make ARCH=x86_64 
>>
>> All errors (new ones prefixed by >>):
>>
>>    drivers/built-in.o: In function `nop_set_peripheral':
>>>> phy-generic.c:(.text+0x14423f): undefined reference to `usb_gadget_vbus_connect'
>>    drivers/built-in.o: In function `nop_gpio_vbus_thread':
>>>> phy-generic.c:(.text+0x144742): undefined reference to `usb_gadget_vbus_disconnect'
>
> oh yeah, I have to fix this. I'll do it now.

In order to fix this, I'll have to add something like below:

diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
index 3644a3500b70..bd67e4ac4b61 100644
--- a/drivers/usb/chipidea/Kconfig
+++ b/drivers/usb/chipidea/Kconfig
@@ -19,6 +19,7 @@ config USB_CHIPIDEA_OF
 config USB_CHIPIDEA_PCI
 	tristate
 	depends on PCI
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
 	depends on NOP_USB_XCEIV
 	default USB_CHIPIDEA
 
diff --git a/drivers/usb/dwc2/Kconfig b/drivers/usb/dwc2/Kconfig
index c1f29caa8990..26327aa2d2d8 100644
--- a/drivers/usb/dwc2/Kconfig
+++ b/drivers/usb/dwc2/Kconfig
@@ -55,8 +55,9 @@ endchoice
 config USB_DWC2_PCI
 	tristate "DWC2 PCI"
 	depends on PCI
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
+	depends on NOP_USB_XCEIV
 	default n
-	select NOP_USB_XCEIV
 	help
 	  The Designware USB2.0 PCI interface module for controllers
 	  connected to a PCI bus.
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index d8f5674809e8..243c3d0cf1dc 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -180,7 +180,8 @@ config USB_EHCI_MXC
 config USB_EHCI_HCD_OMAP
 	tristate "EHCI support for OMAP3 and later chips"
 	depends on ARCH_OMAP
-	select NOP_USB_XCEIV
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
+	depends on NOP_USB_XCEIV
 	default y
 	---help---
 	  Enables support for the on-chip EHCI controller on
diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
index 886526b5fcdd..c8588e5cec75 100644
--- a/drivers/usb/musb/Kconfig
+++ b/drivers/usb/musb/Kconfig
@@ -66,6 +66,7 @@ comment "Platform Glue Layer"
 config USB_MUSB_SUNXI
 	tristate "Allwinner (sunxi)"
 	depends on ARCH_SUNXI
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
 	depends on NOP_USB_XCEIV
 	depends on PHY_SUN4I_USB
 	depends on EXTCON
@@ -75,12 +76,14 @@ config USB_MUSB_SUNXI
 config USB_MUSB_DAVINCI
 	tristate "DaVinci"
 	depends on ARCH_DAVINCI_DMx
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
 	depends on NOP_USB_XCEIV
 	depends on BROKEN
 
 config USB_MUSB_DA8XX
 	tristate "DA8xx/OMAP-L1x"
 	depends on ARCH_DAVINCI_DA8XX
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
 	depends on NOP_USB_XCEIV
 	depends on BROKEN
 
@@ -88,6 +91,7 @@ config USB_MUSB_TUSB6010
 	tristate "TUSB6010"
 	depends on HAS_IOMEM
 	depends on ARCH_OMAP2PLUS || COMPILE_TEST
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
 	depends on NOP_USB_XCEIV = USB_MUSB_HDRC # both built-in or both modules
 
 config USB_MUSB_OMAP2PLUS
@@ -99,6 +103,7 @@ config USB_MUSB_OMAP2PLUS
 config USB_MUSB_AM35X
 	tristate "AM35x"
 	depends on ARCH_OMAP
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
 	depends on NOP_USB_XCEIV
 
 config USB_MUSB_DSPS
@@ -110,6 +115,7 @@ config USB_MUSB_DSPS
 config USB_MUSB_BLACKFIN
 	tristate "Blackfin"
 	depends on (BF54x && !BF544) || (BF52x && ! BF522 && !BF523)
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
 	depends on NOP_USB_XCEIV
 
 config USB_MUSB_UX500
@@ -118,6 +124,7 @@ config USB_MUSB_UX500
 
 config USB_MUSB_JZ4740
 	tristate "JZ4740"
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
 	depends on NOP_USB_XCEIV
 	depends on MACH_JZ4740 || COMPILE_TEST
 	depends on USB_MUSB_GADGET
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index c6904742e2aa..53c0f2220ce3 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -43,7 +43,8 @@ config ISP1301_OMAP
 config KEYSTONE_USB_PHY
 	tristate "Keystone USB PHY Driver"
 	depends on ARCH_KEYSTONE || COMPILE_TEST
-	select NOP_USB_XCEIV
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
+	depends on NOP_USB_XCEIV
 	help
 	  Enable this to support Keystone USB phy. This driver provides
 	  interface to interact with USB 2.0 and USB 3.0 PHY that is part
@@ -63,9 +64,10 @@ config AM335X_CONTROL_USB
 config AM335X_PHY_USB
 	tristate "AM335x USB PHY Driver"
 	depends on ARM || COMPILE_TEST
+	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
+	depends on NOP_USB_XCEIV
 	select USB_PHY
 	select AM335X_CONTROL_USB
-	select NOP_USB_XCEIV
 	select USB_COMMON
 	help
 	  This driver provides PHY support for that phy which part for the


Anybody has any problems with this being amended to original patch? Note
that NOP_USB_XCEIV should never have been selected with "select" to
start with.

-- 
balbi

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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Peter Chen]

On Mon, Jun 06, 2016 at 04:16:17PM +0300, Felipe Balbi wrote:
> 
> Hi,
> 
> Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> writes:
> > [ Unknown signature status ]
> >
> > Hi,
> >
> > kbuild test robot <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:
> >> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
> >> head:   89fe2b5ab11cdf6a67d4492d893e70e330aa7060
> >> commit: 231b31ca34485552fe27e67dc6d30d06079c7648 [64/67] usb: gadget: move gadget API functions to udc-core
> >> config: x86_64-randconfig-s1-06061834 (attached as .config)
> >> compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
> >> reproduce:
> >>         git checkout 231b31ca34485552fe27e67dc6d30d06079c7648
> >>         # save the attached .config to linux build tree
> >>         make ARCH=x86_64 
> >>
> >> All errors (new ones prefixed by >>):
> >>
> >>    drivers/built-in.o: In function `nop_set_peripheral':
> >>>> phy-generic.c:(.text+0x14423f): undefined reference to `usb_gadget_vbus_connect'
> >>    drivers/built-in.o: In function `nop_gpio_vbus_thread':
> >>>> phy-generic.c:(.text+0x144742): undefined reference to `usb_gadget_vbus_disconnect'
> >
> > oh yeah, I have to fix this. I'll do it now.
> 
> In order to fix this, I'll have to add something like below:
> 
> diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
> index 3644a3500b70..bd67e4ac4b61 100644
> --- a/drivers/usb/chipidea/Kconfig
> +++ b/drivers/usb/chipidea/Kconfig
> @@ -19,6 +19,7 @@ config USB_CHIPIDEA_OF
>  config USB_CHIPIDEA_PCI
>  	tristate
>  	depends on PCI
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>  	depends on NOP_USB_XCEIV
>  	default USB_CHIPIDEA

Hi Felipe,

It causes any drivers which use symbols from gadget.h needs to build
USB_GADGET even it only wants to be host function. Any significant
benefits after moving it to udc-core.c?

Peter
>  
> diff --git a/drivers/usb/dwc2/Kconfig b/drivers/usb/dwc2/Kconfig
> index c1f29caa8990..26327aa2d2d8 100644
> --- a/drivers/usb/dwc2/Kconfig
> +++ b/drivers/usb/dwc2/Kconfig
> @@ -55,8 +55,9 @@ endchoice
>  config USB_DWC2_PCI
>  	tristate "DWC2 PCI"
>  	depends on PCI
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	default n
> -	select NOP_USB_XCEIV
>  	help
>  	  The Designware USB2.0 PCI interface module for controllers
>  	  connected to a PCI bus.
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index d8f5674809e8..243c3d0cf1dc 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -180,7 +180,8 @@ config USB_EHCI_MXC
>  config USB_EHCI_HCD_OMAP
>  	tristate "EHCI support for OMAP3 and later chips"
>  	depends on ARCH_OMAP
> -	select NOP_USB_XCEIV
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	default y
>  	---help---
>  	  Enables support for the on-chip EHCI controller on
> diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
> index 886526b5fcdd..c8588e5cec75 100644
> --- a/drivers/usb/musb/Kconfig
> +++ b/drivers/usb/musb/Kconfig
> @@ -66,6 +66,7 @@ comment "Platform Glue Layer"
>  config USB_MUSB_SUNXI
>  	tristate "Allwinner (sunxi)"
>  	depends on ARCH_SUNXI
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>  	depends on NOP_USB_XCEIV
>  	depends on PHY_SUN4I_USB
>  	depends on EXTCON
> @@ -75,12 +76,14 @@ config USB_MUSB_SUNXI
>  config USB_MUSB_DAVINCI
>  	tristate "DaVinci"
>  	depends on ARCH_DAVINCI_DMx
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>  	depends on NOP_USB_XCEIV
>  	depends on BROKEN
>  
>  config USB_MUSB_DA8XX
>  	tristate "DA8xx/OMAP-L1x"
>  	depends on ARCH_DAVINCI_DA8XX
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>  	depends on NOP_USB_XCEIV
>  	depends on BROKEN
>  
> @@ -88,6 +91,7 @@ config USB_MUSB_TUSB6010
>  	tristate "TUSB6010"
>  	depends on HAS_IOMEM
>  	depends on ARCH_OMAP2PLUS || COMPILE_TEST
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>  	depends on NOP_USB_XCEIV = USB_MUSB_HDRC # both built-in or both modules
>  
>  config USB_MUSB_OMAP2PLUS
> @@ -99,6 +103,7 @@ config USB_MUSB_OMAP2PLUS
>  config USB_MUSB_AM35X
>  	tristate "AM35x"
>  	depends on ARCH_OMAP
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>  	depends on NOP_USB_XCEIV
>  
>  config USB_MUSB_DSPS
> @@ -110,6 +115,7 @@ config USB_MUSB_DSPS
>  config USB_MUSB_BLACKFIN
>  	tristate "Blackfin"
>  	depends on (BF54x && !BF544) || (BF52x && ! BF522 && !BF523)
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>  	depends on NOP_USB_XCEIV
>  
>  config USB_MUSB_UX500
> @@ -118,6 +124,7 @@ config USB_MUSB_UX500
>  
>  config USB_MUSB_JZ4740
>  	tristate "JZ4740"
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>  	depends on NOP_USB_XCEIV
>  	depends on MACH_JZ4740 || COMPILE_TEST
>  	depends on USB_MUSB_GADGET
> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
> index c6904742e2aa..53c0f2220ce3 100644
> --- a/drivers/usb/phy/Kconfig
> +++ b/drivers/usb/phy/Kconfig
> @@ -43,7 +43,8 @@ config ISP1301_OMAP
>  config KEYSTONE_USB_PHY
>  	tristate "Keystone USB PHY Driver"
>  	depends on ARCH_KEYSTONE || COMPILE_TEST
> -	select NOP_USB_XCEIV
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	help
>  	  Enable this to support Keystone USB phy. This driver provides
>  	  interface to interact with USB 2.0 and USB 3.0 PHY that is part
> @@ -63,9 +64,10 @@ config AM335X_CONTROL_USB
>  config AM335X_PHY_USB
>  	tristate "AM335x USB PHY Driver"
>  	depends on ARM || COMPILE_TEST
> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	select USB_PHY
>  	select AM335X_CONTROL_USB
> -	select NOP_USB_XCEIV
>  	select USB_COMMON
>  	help
>  	  This driver provides PHY support for that phy which part for the
> 
> 
> Anybody has any problems with this being amended to original patch? Note
> that NOP_USB_XCEIV should never have been selected with "select" to
> start with.
> 
> -- 
> balbi



-- 

Best Regards,
Peter Chen
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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Felipe Balbi]

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Hi,

Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
> On Mon, Jun 06, 2016 at 04:16:17PM +0300, Felipe Balbi wrote:
>> 
>> Hi,
>> 
>> Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> writes:
>> > [ Unknown signature status ]
>> >
>> > Hi,
>> >
>> > kbuild test robot <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:
>> >> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
>> >> head:   89fe2b5ab11cdf6a67d4492d893e70e330aa7060
>> >> commit: 231b31ca34485552fe27e67dc6d30d06079c7648 [64/67] usb: gadget: move gadget API functions to udc-core
>> >> config: x86_64-randconfig-s1-06061834 (attached as .config)
>> >> compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
>> >> reproduce:
>> >>         git checkout 231b31ca34485552fe27e67dc6d30d06079c7648
>> >>         # save the attached .config to linux build tree
>> >>         make ARCH=x86_64 
>> >>
>> >> All errors (new ones prefixed by >>):
>> >>
>> >>    drivers/built-in.o: In function `nop_set_peripheral':
>> >>>> phy-generic.c:(.text+0x14423f): undefined reference to `usb_gadget_vbus_connect'
>> >>    drivers/built-in.o: In function `nop_gpio_vbus_thread':
>> >>>> phy-generic.c:(.text+0x144742): undefined reference to `usb_gadget_vbus_disconnect'
>> >
>> > oh yeah, I have to fix this. I'll do it now.
>> 
>> In order to fix this, I'll have to add something like below:
>> 
>> diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
>> index 3644a3500b70..bd67e4ac4b61 100644
>> --- a/drivers/usb/chipidea/Kconfig
>> +++ b/drivers/usb/chipidea/Kconfig
>> @@ -19,6 +19,7 @@ config USB_CHIPIDEA_OF
>>  config USB_CHIPIDEA_PCI
>>  	tristate
>>  	depends on PCI
>> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>>  	depends on NOP_USB_XCEIV
>>  	default USB_CHIPIDEA
>
> Hi Felipe,
>
> It causes any drivers which use symbols from gadget.h needs to build
> USB_GADGET even it only wants to be host function. Any significant
> benefits after moving it to udc-core.c?

why is a host-only function calling into the gadget API?

-- 
balbi

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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Peter Chen]

On Tue, Jun 07, 2016 at 12:36:13PM +0300, Felipe Balbi wrote:
> 
> Hi,
> 
> Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
> > On Mon, Jun 06, 2016 at 04:16:17PM +0300, Felipe Balbi wrote:
> >> 
> >> Hi,
> >> 
> >> Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> writes:
> >> > [ Unknown signature status ]
> >> >
> >> > Hi,
> >> >
> >> > kbuild test robot <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:
> >> >> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
> >> >> head:   89fe2b5ab11cdf6a67d4492d893e70e330aa7060
> >> >> commit: 231b31ca34485552fe27e67dc6d30d06079c7648 [64/67] usb: gadget: move gadget API functions to udc-core
> >> >> config: x86_64-randconfig-s1-06061834 (attached as .config)
> >> >> compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
> >> >> reproduce:
> >> >>         git checkout 231b31ca34485552fe27e67dc6d30d06079c7648
> >> >>         # save the attached .config to linux build tree
> >> >>         make ARCH=x86_64 
> >> >>
> >> >> All errors (new ones prefixed by >>):
> >> >>
> >> >>    drivers/built-in.o: In function `nop_set_peripheral':
> >> >>>> phy-generic.c:(.text+0x14423f): undefined reference to `usb_gadget_vbus_connect'
> >> >>    drivers/built-in.o: In function `nop_gpio_vbus_thread':
> >> >>>> phy-generic.c:(.text+0x144742): undefined reference to `usb_gadget_vbus_disconnect'
> >> >
> >> > oh yeah, I have to fix this. I'll do it now.
> >> 
> >> In order to fix this, I'll have to add something like below:
> >> 
> >> diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
> >> index 3644a3500b70..bd67e4ac4b61 100644
> >> --- a/drivers/usb/chipidea/Kconfig
> >> +++ b/drivers/usb/chipidea/Kconfig
> >> @@ -19,6 +19,7 @@ config USB_CHIPIDEA_OF
> >>  config USB_CHIPIDEA_PCI
> >>  	tristate
> >>  	depends on PCI
> >> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
> >>  	depends on NOP_USB_XCEIV
> >>  	default USB_CHIPIDEA
> >
> > Hi Felipe,
> >
> > It causes any drivers which use symbols from gadget.h needs to build
> > USB_GADGET even it only wants to be host function. Any significant
> > benefits after moving it to udc-core.c?
> 
> why is a host-only function calling into the gadget API?
> 

Well, Just like this case, the chipidea driver can be configured host
mode only, but it still uses generic phy.

Besides, we have some common code which handles vbus status, this code
will be built even at host-only mode, but will not be called since the
runtime condition is not satisfied, eg, dr_mode, device role at
register.

-- 

Best Regards,
Peter Chen
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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 50107 bytes --]


Hi,

Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
>> >> > kbuild test robot <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:
>> >> >> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
>> >> >> head:   89fe2b5ab11cdf6a67d4492d893e70e330aa7060
>> >> >> commit: 231b31ca34485552fe27e67dc6d30d06079c7648 [64/67] usb: gadget: move gadget API functions to udc-core
>> >> >> config: x86_64-randconfig-s1-06061834 (attached as .config)
>> >> >> compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
>> >> >> reproduce:
>> >> >>         git checkout 231b31ca34485552fe27e67dc6d30d06079c7648
>> >> >>         # save the attached .config to linux build tree
>> >> >>         make ARCH=x86_64 
>> >> >>
>> >> >> All errors (new ones prefixed by >>):
>> >> >>
>> >> >>    drivers/built-in.o: In function `nop_set_peripheral':
>> >> >>>> phy-generic.c:(.text+0x14423f): undefined reference to `usb_gadget_vbus_connect'
>> >> >>    drivers/built-in.o: In function `nop_gpio_vbus_thread':
>> >> >>>> phy-generic.c:(.text+0x144742): undefined reference to `usb_gadget_vbus_disconnect'
>> >> >
>> >> > oh yeah, I have to fix this. I'll do it now.
>> >> 
>> >> In order to fix this, I'll have to add something like below:
>> >> 
>> >> diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
>> >> index 3644a3500b70..bd67e4ac4b61 100644
>> >> --- a/drivers/usb/chipidea/Kconfig
>> >> +++ b/drivers/usb/chipidea/Kconfig
>> >> @@ -19,6 +19,7 @@ config USB_CHIPIDEA_OF
>> >>  config USB_CHIPIDEA_PCI
>> >>  	tristate
>> >>  	depends on PCI
>> >> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
>> >>  	depends on NOP_USB_XCEIV
>> >>  	default USB_CHIPIDEA
>> >
>> > Hi Felipe,
>> >
>> > It causes any drivers which use symbols from gadget.h needs to build
>> > USB_GADGET even it only wants to be host function. Any significant
>> > benefits after moving it to udc-core.c?
>> 
>> why is a host-only function calling into the gadget API?
>> 
>
> Well, Just like this case, the chipidea driver can be configured host
> mode only, but it still uses generic phy.

then we should allow for PHYs to not depend on the Gadget API, right?

> Besides, we have some common code which handles vbus status, this code
> will be built even at host-only mode, but will not be called since the
> runtime condition is not satisfied, eg, dr_mode, device role at
> register.

driver shouldn't depend on the gadget API if it's not built with Gadget
support. Look at dwc3 for instance. All gadget API-related code is
stashed in ep0.c and gadget.c, but those only get built if the driver
was built with gadget support:

Kconfig
=======

8<------------------------------------------------------------------------

choice
	bool "DWC3 Mode Selection"
	default USB_DWC3_DUAL_ROLE if (USB && USB_GADGET)
	default USB_DWC3_HOST if (USB && !USB_GADGET)
	default USB_DWC3_GADGET if (!USB && USB_GADGET)

config USB_DWC3_HOST
	bool "Host only mode"
	depends on USB=y || USB=USB_DWC3
	help
	  Select this when you want to use DWC3 in host mode only,
	  thereby the gadget feature will be regressed.

config USB_DWC3_GADGET
	bool "Gadget only mode"
	depends on USB_GADGET=y || USB_GADGET=USB_DWC3
	help
	  Select this when you want to use DWC3 in gadget mode only,
	  thereby the host feature will be regressed.

config USB_DWC3_DUAL_ROLE
	bool "Dual Role mode"
	depends on ((USB=y || USB=USB_DWC3) && (USB_GADGET=y || USB_GADGET=USB_DWC3))
	help
	  This is the default mode of working of DWC3 controller where
	  both host and gadget features are enabled.

endchoice

8<------------------------------------------------------------------------


Makefile
========

8<------------------------------------------------------------------------

ifneq ($(filter y,$(CONFIG_USB_DWC3_GADGET) $(CONFIG_USB_DWC3_DUAL_ROLE)),)
	dwc3-y				+= gadget.o ep0.o
endif

8<------------------------------------------------------------------------

In any case, here's a better version of this patch:

commit 9062bc60311d0a4bbe84e2aa3ec7c2cba06356e4
Author: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Date:   Tue May 31 13:07:47 2016 +0300

    usb: gadget: move gadget API functions to udc-core
    
    instead of defining all functions as static inlines,
    let's move them to udc-core and export them with
    EXPORT_SYMBOL_GPL, that way we can make sure that
    only GPL drivers will use them.
    
    As a side effect, it'll be nicer to add tracepoints
    to the gadget API.
    
    While at that, also fix Kconfig dependencies to
    avoid randconfig build failures.
    
    Signed-off-by: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index 6e8300d6a737..d2f28bb6dbda 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -59,6 +59,579 @@ static int udc_bind_to_driver(struct usb_udc *udc,
 
 /* ------------------------------------------------------------------------- */
 
+/**
+ * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
+ * @ep:the endpoint being configured
+ * @maxpacket_limit:value of maximum packet size limit
+ *
+ * This function should be used only in UDC drivers to initialize endpoint
+ * (usually in probe function).
+ */
+void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
+					      unsigned maxpacket_limit)
+{
+	ep->maxpacket_limit = maxpacket_limit;
+	ep->maxpacket = maxpacket_limit;
+}
+EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
+
+/**
+ * usb_ep_enable - configure endpoint, making it usable
+ * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
+ *	drivers discover endpoints through the ep_list of a usb_gadget.
+ *
+ * When configurations are set, or when interface settings change, the driver
+ * will enable or disable the relevant endpoints.  while it is enabled, an
+ * endpoint may be used for i/o until the driver receives a disconnect() from
+ * the host or until the endpoint is disabled.
+ *
+ * the ep0 implementation (which calls this routine) must ensure that the
+ * hardware capabilities of each endpoint match the descriptor provided
+ * for it.  for example, an endpoint named "ep2in-bulk" would be usable
+ * for interrupt transfers as well as bulk, but it likely couldn't be used
+ * for iso transfers or for endpoint 14.  some endpoints are fully
+ * configurable, with more generic names like "ep-a".  (remember that for
+ * USB, "in" means "towards the USB master".)
+ *
+ * returns zero, or a negative error code.
+ */
+int usb_ep_enable(struct usb_ep *ep)
+{
+	int ret;
+
+	if (ep->enabled)
+		return 0;
+
+	ret = ep->ops->enable(ep, ep->desc);
+	if (ret)
+		return ret;
+
+	ep->enabled = true;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_ep_enable);
+
+/**
+ * usb_ep_disable - endpoint is no longer usable
+ * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
+ *
+ * no other task may be using this endpoint when this is called.
+ * any pending and uncompleted requests will complete with status
+ * indicating disconnect (-ESHUTDOWN) before this call returns.
+ * gadget drivers must call usb_ep_enable() again before queueing
+ * requests to the endpoint.
+ *
+ * returns zero, or a negative error code.
+ */
+int usb_ep_disable(struct usb_ep *ep)
+{
+	int ret;
+
+	if (!ep->enabled)
+		return 0;
+
+	ret = ep->ops->disable(ep);
+	if (ret)
+		return ret;
+
+	ep->enabled = false;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_ep_disable);
+
+/**
+ * usb_ep_alloc_request - allocate a request object to use with this endpoint
+ * @ep:the endpoint to be used with with the request
+ * @gfp_flags:GFP_* flags to use
+ *
+ * Request objects must be allocated with this call, since they normally
+ * need controller-specific setup and may even need endpoint-specific
+ * resources such as allocation of DMA descriptors.
+ * Requests may be submitted with usb_ep_queue(), and receive a single
+ * completion callback.  Free requests with usb_ep_free_request(), when
+ * they are no longer needed.
+ *
+ * Returns the request, or null if one could not be allocated.
+ */
+struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
+						       gfp_t gfp_flags)
+{
+	return ep->ops->alloc_request(ep, gfp_flags);
+}
+EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
+
+/**
+ * usb_ep_free_request - frees a request object
+ * @ep:the endpoint associated with the request
+ * @req:the request being freed
+ *
+ * Reverses the effect of usb_ep_alloc_request().
+ * Caller guarantees the request is not queued, and that it will
+ * no longer be requeued (or otherwise used).
+ */
+void usb_ep_free_request(struct usb_ep *ep,
+				       struct usb_request *req)
+{
+	ep->ops->free_request(ep, req);
+}
+EXPORT_SYMBOL_GPL(usb_ep_free_request);
+
+/**
+ * usb_ep_queue - queues (submits) an I/O request to an endpoint.
+ * @ep:the endpoint associated with the request
+ * @req:the request being submitted
+ * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
+ *	pre-allocate all necessary memory with the request.
+ *
+ * This tells the device controller to perform the specified request through
+ * that endpoint (reading or writing a buffer).  When the request completes,
+ * including being canceled by usb_ep_dequeue(), the request's completion
+ * routine is called to return the request to the driver.  Any endpoint
+ * (except control endpoints like ep0) may have more than one transfer
+ * request queued; they complete in FIFO order.  Once a gadget driver
+ * submits a request, that request may not be examined or modified until it
+ * is given back to that driver through the completion callback.
+ *
+ * Each request is turned into one or more packets.  The controller driver
+ * never merges adjacent requests into the same packet.  OUT transfers
+ * will sometimes use data that's already buffered in the hardware.
+ * Drivers can rely on the fact that the first byte of the request's buffer
+ * always corresponds to the first byte of some USB packet, for both
+ * IN and OUT transfers.
+ *
+ * Bulk endpoints can queue any amount of data; the transfer is packetized
+ * automatically.  The last packet will be short if the request doesn't fill it
+ * out completely.  Zero length packets (ZLPs) should be avoided in portable
+ * protocols since not all usb hardware can successfully handle zero length
+ * packets.  (ZLPs may be explicitly written, and may be implicitly written if
+ * the request 'zero' flag is set.)  Bulk endpoints may also be used
+ * for interrupt transfers; but the reverse is not true, and some endpoints
+ * won't support every interrupt transfer.  (Such as 768 byte packets.)
+ *
+ * Interrupt-only endpoints are less functional than bulk endpoints, for
+ * example by not supporting queueing or not handling buffers that are
+ * larger than the endpoint's maxpacket size.  They may also treat data
+ * toggle differently.
+ *
+ * Control endpoints ... after getting a setup() callback, the driver queues
+ * one response (even if it would be zero length).  That enables the
+ * status ack, after transferring data as specified in the response.  Setup
+ * functions may return negative error codes to generate protocol stalls.
+ * (Note that some USB device controllers disallow protocol stall responses
+ * in some cases.)  When control responses are deferred (the response is
+ * written after the setup callback returns), then usb_ep_set_halt() may be
+ * used on ep0 to trigger protocol stalls.  Depending on the controller,
+ * it may not be possible to trigger a status-stage protocol stall when the
+ * data stage is over, that is, from within the response's completion
+ * routine.
+ *
+ * For periodic endpoints, like interrupt or isochronous ones, the usb host
+ * arranges to poll once per interval, and the gadget driver usually will
+ * have queued some data to transfer at that time.
+ *
+ * Returns zero, or a negative error code.  Endpoints that are not enabled
+ * report errors; errors will also be
+ * reported when the usb peripheral is disconnected.
+ */
+int usb_ep_queue(struct usb_ep *ep,
+			       struct usb_request *req, gfp_t gfp_flags)
+{
+	if (WARN_ON_ONCE(!ep->enabled && ep->address))
+		return -ESHUTDOWN;
+
+	return ep->ops->queue(ep, req, gfp_flags);
+}
+EXPORT_SYMBOL_GPL(usb_ep_queue);
+
+/**
+ * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
+ * @ep:the endpoint associated with the request
+ * @req:the request being canceled
+ *
+ * If the request is still active on the endpoint, it is dequeued and its
+ * completion routine is called (with status -ECONNRESET); else a negative
+ * error code is returned. This is guaranteed to happen before the call to
+ * usb_ep_dequeue() returns.
+ *
+ * Note that some hardware can't clear out write fifos (to unlink the request
+ * at the head of the queue) except as part of disconnecting from usb. Such
+ * restrictions prevent drivers from supporting configuration changes,
+ * even to configuration zero (a "chapter 9" requirement).
+ */
+int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
+{
+	return ep->ops->dequeue(ep, req);
+}
+EXPORT_SYMBOL_GPL(usb_ep_dequeue);
+
+/**
+ * usb_ep_set_halt - sets the endpoint halt feature.
+ * @ep: the non-isochronous endpoint being stalled
+ *
+ * Use this to stall an endpoint, perhaps as an error report.
+ * Except for control endpoints,
+ * the endpoint stays halted (will not stream any data) until the host
+ * clears this feature; drivers may need to empty the endpoint's request
+ * queue first, to make sure no inappropriate transfers happen.
+ *
+ * Note that while an endpoint CLEAR_FEATURE will be invisible to the
+ * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
+ * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
+ * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
+ *
+ * Returns zero, or a negative error code.  On success, this call sets
+ * underlying hardware state that blocks data transfers.
+ * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
+ * transfer requests are still queued, or if the controller hardware
+ * (usually a FIFO) still holds bytes that the host hasn't collected.
+ */
+int usb_ep_set_halt(struct usb_ep *ep)
+{
+	return ep->ops->set_halt(ep, 1);
+}
+EXPORT_SYMBOL_GPL(usb_ep_set_halt);
+
+/**
+ * usb_ep_clear_halt - clears endpoint halt, and resets toggle
+ * @ep:the bulk or interrupt endpoint being reset
+ *
+ * Use this when responding to the standard usb "set interface" request,
+ * for endpoints that aren't reconfigured, after clearing any other state
+ * in the endpoint's i/o queue.
+ *
+ * Returns zero, or a negative error code.  On success, this call clears
+ * the underlying hardware state reflecting endpoint halt and data toggle.
+ * Note that some hardware can't support this request (like pxa2xx_udc),
+ * and accordingly can't correctly implement interface altsettings.
+ */
+int usb_ep_clear_halt(struct usb_ep *ep)
+{
+	return ep->ops->set_halt(ep, 0);
+}
+EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
+
+/**
+ * usb_ep_set_wedge - sets the halt feature and ignores clear requests
+ * @ep: the endpoint being wedged
+ *
+ * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
+ * requests. If the gadget driver clears the halt status, it will
+ * automatically unwedge the endpoint.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_ep_set_wedge(struct usb_ep *ep)
+{
+	if (ep->ops->set_wedge)
+		return ep->ops->set_wedge(ep);
+	else
+		return ep->ops->set_halt(ep, 1);
+}
+EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
+
+/**
+ * usb_ep_fifo_status - returns number of bytes in fifo, or error
+ * @ep: the endpoint whose fifo status is being checked.
+ *
+ * FIFO endpoints may have "unclaimed data" in them in certain cases,
+ * such as after aborted transfers.  Hosts may not have collected all
+ * the IN data written by the gadget driver (and reported by a request
+ * completion).  The gadget driver may not have collected all the data
+ * written OUT to it by the host.  Drivers that need precise handling for
+ * fault reporting or recovery may need to use this call.
+ *
+ * This returns the number of such bytes in the fifo, or a negative
+ * errno if the endpoint doesn't use a FIFO or doesn't support such
+ * precise handling.
+ */
+int usb_ep_fifo_status(struct usb_ep *ep)
+{
+	if (ep->ops->fifo_status)
+		return ep->ops->fifo_status(ep);
+	else
+		return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
+
+/**
+ * usb_ep_fifo_flush - flushes contents of a fifo
+ * @ep: the endpoint whose fifo is being flushed.
+ *
+ * This call may be used to flush the "unclaimed data" that may exist in
+ * an endpoint fifo after abnormal transaction terminations.  The call
+ * must never be used except when endpoint is not being used for any
+ * protocol translation.
+ */
+void usb_ep_fifo_flush(struct usb_ep *ep)
+{
+	if (ep->ops->fifo_flush)
+		ep->ops->fifo_flush(ep);
+}
+EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
+
+/* ------------------------------------------------------------------------- */
+
+/**
+ * usb_gadget_frame_number - returns the current frame number
+ * @gadget: controller that reports the frame number
+ *
+ * Returns the usb frame number, normally eleven bits from a SOF packet,
+ * or negative errno if this device doesn't support this capability.
+ */
+int usb_gadget_frame_number(struct usb_gadget *gadget)
+{
+	return gadget->ops->get_frame(gadget);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
+
+/**
+ * usb_gadget_wakeup - tries to wake up the host connected to this gadget
+ * @gadget: controller used to wake up the host
+ *
+ * Returns zero on success, else negative error code if the hardware
+ * doesn't support such attempts, or its support has not been enabled
+ * by the usb host.  Drivers must return device descriptors that report
+ * their ability to support this, or hosts won't enable it.
+ *
+ * This may also try to use SRP to wake the host and start enumeration,
+ * even if OTG isn't otherwise in use.  OTG devices may also start
+ * remote wakeup even when hosts don't explicitly enable it.
+ */
+int usb_gadget_wakeup(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->wakeup)
+		return -EOPNOTSUPP;
+	return gadget->ops->wakeup(gadget);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
+
+/**
+ * usb_gadget_set_selfpowered - sets the device selfpowered feature.
+ * @gadget:the device being declared as self-powered
+ *
+ * this affects the device status reported by the hardware driver
+ * to reflect that it now has a local power supply.
+ *
+ * returns zero on success, else negative errno.
+ */
+int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->set_selfpowered)
+		return -EOPNOTSUPP;
+	return gadget->ops->set_selfpowered(gadget, 1);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
+
+/**
+ * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
+ * @gadget:the device being declared as bus-powered
+ *
+ * this affects the device status reported by the hardware driver.
+ * some hardware may not support bus-powered operation, in which
+ * case this feature's value can never change.
+ *
+ * returns zero on success, else negative errno.
+ */
+int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->set_selfpowered)
+		return -EOPNOTSUPP;
+	return gadget->ops->set_selfpowered(gadget, 0);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
+
+/**
+ * usb_gadget_vbus_connect - Notify controller that VBUS is powered
+ * @gadget:The device which now has VBUS power.
+ * Context: can sleep
+ *
+ * This call is used by a driver for an external transceiver (or GPIO)
+ * that detects a VBUS power session starting.  Common responses include
+ * resuming the controller, activating the D+ (or D-) pullup to let the
+ * host detect that a USB device is attached, and starting to draw power
+ * (8mA or possibly more, especially after SET_CONFIGURATION).
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_vbus_connect(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->vbus_session)
+		return -EOPNOTSUPP;
+	return gadget->ops->vbus_session(gadget, 1);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
+
+/**
+ * usb_gadget_vbus_draw - constrain controller's VBUS power usage
+ * @gadget:The device whose VBUS usage is being described
+ * @mA:How much current to draw, in milliAmperes.  This should be twice
+ *	the value listed in the configuration descriptor bMaxPower field.
+ *
+ * This call is used by gadget drivers during SET_CONFIGURATION calls,
+ * reporting how much power the device may consume.  For example, this
+ * could affect how quickly batteries are recharged.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
+{
+	if (!gadget->ops->vbus_draw)
+		return -EOPNOTSUPP;
+	return gadget->ops->vbus_draw(gadget, mA);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
+
+/**
+ * usb_gadget_vbus_disconnect - notify controller about VBUS session end
+ * @gadget:the device whose VBUS supply is being described
+ * Context: can sleep
+ *
+ * This call is used by a driver for an external transceiver (or GPIO)
+ * that detects a VBUS power session ending.  Common responses include
+ * reversing everything done in usb_gadget_vbus_connect().
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->vbus_session)
+		return -EOPNOTSUPP;
+	return gadget->ops->vbus_session(gadget, 0);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
+
+/**
+ * usb_gadget_connect - software-controlled connect to USB host
+ * @gadget:the peripheral being connected
+ *
+ * Enables the D+ (or potentially D-) pullup.  The host will start
+ * enumerating this gadget when the pullup is active and a VBUS session
+ * is active (the link is powered).  This pullup is always enabled unless
+ * usb_gadget_disconnect() has been used to disable it.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_connect(struct usb_gadget *gadget)
+{
+	int ret;
+
+	if (!gadget->ops->pullup)
+		return -EOPNOTSUPP;
+
+	if (gadget->deactivated) {
+		/*
+		 * If gadget is deactivated we only save new state.
+		 * Gadget will be connected automatically after activation.
+		 */
+		gadget->connected = true;
+		return 0;
+	}
+
+	ret = gadget->ops->pullup(gadget, 1);
+	if (!ret)
+		gadget->connected = 1;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_connect);
+
+/**
+ * usb_gadget_disconnect - software-controlled disconnect from USB host
+ * @gadget:the peripheral being disconnected
+ *
+ * Disables the D+ (or potentially D-) pullup, which the host may see
+ * as a disconnect (when a VBUS session is active).  Not all systems
+ * support software pullup controls.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_disconnect(struct usb_gadget *gadget)
+{
+	int ret;
+
+	if (!gadget->ops->pullup)
+		return -EOPNOTSUPP;
+
+	if (gadget->deactivated) {
+		/*
+		 * If gadget is deactivated we only save new state.
+		 * Gadget will stay disconnected after activation.
+		 */
+		gadget->connected = false;
+		return 0;
+	}
+
+	ret = gadget->ops->pullup(gadget, 0);
+	if (!ret)
+		gadget->connected = 0;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
+
+/**
+ * usb_gadget_deactivate - deactivate function which is not ready to work
+ * @gadget: the peripheral being deactivated
+ *
+ * This routine may be used during the gadget driver bind() call to prevent
+ * the peripheral from ever being visible to the USB host, unless later
+ * usb_gadget_activate() is called.  For example, user mode components may
+ * need to be activated before the system can talk to hosts.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_deactivate(struct usb_gadget *gadget)
+{
+	int ret;
+
+	if (gadget->deactivated)
+		return 0;
+
+	if (gadget->connected) {
+		ret = usb_gadget_disconnect(gadget);
+		if (ret)
+			return ret;
+		/*
+		 * If gadget was being connected before deactivation, we want
+		 * to reconnect it in usb_gadget_activate().
+		 */
+		gadget->connected = true;
+	}
+	gadget->deactivated = true;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
+
+/**
+ * usb_gadget_activate - activate function which is not ready to work
+ * @gadget: the peripheral being activated
+ *
+ * This routine activates gadget which was previously deactivated with
+ * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_activate(struct usb_gadget *gadget)
+{
+	if (!gadget->deactivated)
+		return 0;
+
+	gadget->deactivated = false;
+
+	/*
+	 * If gadget has been connected before deactivation, or became connected
+	 * while it was being deactivated, we call usb_gadget_connect().
+	 */
+	if (gadget->connected)
+		return usb_gadget_connect(gadget);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_activate);
+
+/* ------------------------------------------------------------------------- */
+
 #ifdef	CONFIG_HAS_DMA
 
 int usb_gadget_map_request_by_dev(struct device *dev,
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index d8f5674809e8..2e710a4cca52 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -180,7 +180,7 @@ config USB_EHCI_MXC
 config USB_EHCI_HCD_OMAP
 	tristate "EHCI support for OMAP3 and later chips"
 	depends on ARCH_OMAP
-	select NOP_USB_XCEIV
+	depends on NOP_USB_XCEIV
 	default y
 	---help---
 	  Enables support for the on-chip EHCI controller on
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index c6904742e2aa..ca509448b844 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -43,7 +43,7 @@ config ISP1301_OMAP
 config KEYSTONE_USB_PHY
 	tristate "Keystone USB PHY Driver"
 	depends on ARCH_KEYSTONE || COMPILE_TEST
-	select NOP_USB_XCEIV
+	depends on NOP_USB_XCEIV
 	help
 	  Enable this to support Keystone USB phy. This driver provides
 	  interface to interact with USB 2.0 and USB 3.0 PHY that is part
@@ -51,6 +51,7 @@ config KEYSTONE_USB_PHY
 
 config NOP_USB_XCEIV
 	tristate "NOP USB Transceiver Driver"
+	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, NOP can't be built-in
 	select USB_PHY
 	help
 	  This driver is to be used by all the usb transceiver which are either
@@ -63,9 +64,9 @@ config AM335X_CONTROL_USB
 config AM335X_PHY_USB
 	tristate "AM335x USB PHY Driver"
 	depends on ARM || COMPILE_TEST
+	depends on NOP_USB_XCEIV
 	select USB_PHY
 	select AM335X_CONTROL_USB
-	select NOP_USB_XCEIV
 	select USB_COMMON
 	help
 	  This driver provides PHY support for that phy which part for the
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 457651bf45b0..4cfc1ea352bb 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -228,307 +228,49 @@ struct usb_ep {
 
 /*-------------------------------------------------------------------------*/
 
-/**
- * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
- * @ep:the endpoint being configured
- * @maxpacket_limit:value of maximum packet size limit
- *
- * This function should be used only in UDC drivers to initialize endpoint
- * (usually in probe function).
- */
+#if IS_ENABLED(CONFIG_USB_GADGET)
+void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
+int usb_ep_enable(struct usb_ep *ep);
+int usb_ep_disable(struct usb_ep *ep);
+struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
+void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
+int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
+int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
+int usb_ep_set_halt(struct usb_ep *ep);
+int usb_ep_clear_halt(struct usb_ep *ep);
+int usb_ep_set_wedge(struct usb_ep *ep);
+int usb_ep_fifo_status(struct usb_ep *ep);
+void usb_ep_fifo_flush(struct usb_ep *ep);
+#else
 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
-					      unsigned maxpacket_limit)
-{
-	ep->maxpacket_limit = maxpacket_limit;
-	ep->maxpacket = maxpacket_limit;
-}
-
-/**
- * usb_ep_enable - configure endpoint, making it usable
- * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
- *	drivers discover endpoints through the ep_list of a usb_gadget.
- *
- * When configurations are set, or when interface settings change, the driver
- * will enable or disable the relevant endpoints.  while it is enabled, an
- * endpoint may be used for i/o until the driver receives a disconnect() from
- * the host or until the endpoint is disabled.
- *
- * the ep0 implementation (which calls this routine) must ensure that the
- * hardware capabilities of each endpoint match the descriptor provided
- * for it.  for example, an endpoint named "ep2in-bulk" would be usable
- * for interrupt transfers as well as bulk, but it likely couldn't be used
- * for iso transfers or for endpoint 14.  some endpoints are fully
- * configurable, with more generic names like "ep-a".  (remember that for
- * USB, "in" means "towards the USB master".)
- *
- * returns zero, or a negative error code.
- */
+		unsigned maxpacket_limit)
+{ }
 static inline int usb_ep_enable(struct usb_ep *ep)
-{
-	int ret;
-
-	if (ep->enabled)
-		return 0;
-
-	ret = ep->ops->enable(ep, ep->desc);
-	if (ret)
-		return ret;
-
-	ep->enabled = true;
-
-	return 0;
-}
-
-/**
- * usb_ep_disable - endpoint is no longer usable
- * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
- *
- * no other task may be using this endpoint when this is called.
- * any pending and uncompleted requests will complete with status
- * indicating disconnect (-ESHUTDOWN) before this call returns.
- * gadget drivers must call usb_ep_enable() again before queueing
- * requests to the endpoint.
- *
- * returns zero, or a negative error code.
- */
+{ return 0; }
 static inline int usb_ep_disable(struct usb_ep *ep)
-{
-	int ret;
-
-	if (!ep->enabled)
-		return 0;
-
-	ret = ep->ops->disable(ep);
-	if (ret)
-		return ret;
-
-	ep->enabled = false;
-
-	return 0;
-}
-
-/**
- * usb_ep_alloc_request - allocate a request object to use with this endpoint
- * @ep:the endpoint to be used with with the request
- * @gfp_flags:GFP_* flags to use
- *
- * Request objects must be allocated with this call, since they normally
- * need controller-specific setup and may even need endpoint-specific
- * resources such as allocation of DMA descriptors.
- * Requests may be submitted with usb_ep_queue(), and receive a single
- * completion callback.  Free requests with usb_ep_free_request(), when
- * they are no longer needed.
- *
- * Returns the request, or null if one could not be allocated.
- */
+{ return 0; }
 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
-						       gfp_t gfp_flags)
-{
-	return ep->ops->alloc_request(ep, gfp_flags);
-}
-
-/**
- * usb_ep_free_request - frees a request object
- * @ep:the endpoint associated with the request
- * @req:the request being freed
- *
- * Reverses the effect of usb_ep_alloc_request().
- * Caller guarantees the request is not queued, and that it will
- * no longer be requeued (or otherwise used).
- */
+		gfp_t gfp_flags)
+{ return NULL; }
 static inline void usb_ep_free_request(struct usb_ep *ep,
-				       struct usb_request *req)
-{
-	ep->ops->free_request(ep, req);
-}
-
-/**
- * usb_ep_queue - queues (submits) an I/O request to an endpoint.
- * @ep:the endpoint associated with the request
- * @req:the request being submitted
- * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
- *	pre-allocate all necessary memory with the request.
- *
- * This tells the device controller to perform the specified request through
- * that endpoint (reading or writing a buffer).  When the request completes,
- * including being canceled by usb_ep_dequeue(), the request's completion
- * routine is called to return the request to the driver.  Any endpoint
- * (except control endpoints like ep0) may have more than one transfer
- * request queued; they complete in FIFO order.  Once a gadget driver
- * submits a request, that request may not be examined or modified until it
- * is given back to that driver through the completion callback.
- *
- * Each request is turned into one or more packets.  The controller driver
- * never merges adjacent requests into the same packet.  OUT transfers
- * will sometimes use data that's already buffered in the hardware.
- * Drivers can rely on the fact that the first byte of the request's buffer
- * always corresponds to the first byte of some USB packet, for both
- * IN and OUT transfers.
- *
- * Bulk endpoints can queue any amount of data; the transfer is packetized
- * automatically.  The last packet will be short if the request doesn't fill it
- * out completely.  Zero length packets (ZLPs) should be avoided in portable
- * protocols since not all usb hardware can successfully handle zero length
- * packets.  (ZLPs may be explicitly written, and may be implicitly written if
- * the request 'zero' flag is set.)  Bulk endpoints may also be used
- * for interrupt transfers; but the reverse is not true, and some endpoints
- * won't support every interrupt transfer.  (Such as 768 byte packets.)
- *
- * Interrupt-only endpoints are less functional than bulk endpoints, for
- * example by not supporting queueing or not handling buffers that are
- * larger than the endpoint's maxpacket size.  They may also treat data
- * toggle differently.
- *
- * Control endpoints ... after getting a setup() callback, the driver queues
- * one response (even if it would be zero length).  That enables the
- * status ack, after transferring data as specified in the response.  Setup
- * functions may return negative error codes to generate protocol stalls.
- * (Note that some USB device controllers disallow protocol stall responses
- * in some cases.)  When control responses are deferred (the response is
- * written after the setup callback returns), then usb_ep_set_halt() may be
- * used on ep0 to trigger protocol stalls.  Depending on the controller,
- * it may not be possible to trigger a status-stage protocol stall when the
- * data stage is over, that is, from within the response's completion
- * routine.
- *
- * For periodic endpoints, like interrupt or isochronous ones, the usb host
- * arranges to poll once per interval, and the gadget driver usually will
- * have queued some data to transfer at that time.
- *
- * Returns zero, or a negative error code.  Endpoints that are not enabled
- * report errors; errors will also be
- * reported when the usb peripheral is disconnected.
- */
-static inline int usb_ep_queue(struct usb_ep *ep,
-			       struct usb_request *req, gfp_t gfp_flags)
-{
-	if (WARN_ON_ONCE(!ep->enabled && ep->address))
-		return -ESHUTDOWN;
-
-	return ep->ops->queue(ep, req, gfp_flags);
-}
-
-/**
- * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
- * @ep:the endpoint associated with the request
- * @req:the request being canceled
- *
- * If the request is still active on the endpoint, it is dequeued and its
- * completion routine is called (with status -ECONNRESET); else a negative
- * error code is returned. This is guaranteed to happen before the call to
- * usb_ep_dequeue() returns.
- *
- * Note that some hardware can't clear out write fifos (to unlink the request
- * at the head of the queue) except as part of disconnecting from usb. Such
- * restrictions prevent drivers from supporting configuration changes,
- * even to configuration zero (a "chapter 9" requirement).
- */
+		struct usb_request *req)
+{ }
+static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
+		gfp_t gfp_flags)
+{ return 0; }
 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
-{
-	return ep->ops->dequeue(ep, req);
-}
-
-/**
- * usb_ep_set_halt - sets the endpoint halt feature.
- * @ep: the non-isochronous endpoint being stalled
- *
- * Use this to stall an endpoint, perhaps as an error report.
- * Except for control endpoints,
- * the endpoint stays halted (will not stream any data) until the host
- * clears this feature; drivers may need to empty the endpoint's request
- * queue first, to make sure no inappropriate transfers happen.
- *
- * Note that while an endpoint CLEAR_FEATURE will be invisible to the
- * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
- * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
- * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
- *
- * Returns zero, or a negative error code.  On success, this call sets
- * underlying hardware state that blocks data transfers.
- * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
- * transfer requests are still queued, or if the controller hardware
- * (usually a FIFO) still holds bytes that the host hasn't collected.
- */
+{ return 0; }
 static inline int usb_ep_set_halt(struct usb_ep *ep)
-{
-	return ep->ops->set_halt(ep, 1);
-}
-
-/**
- * usb_ep_clear_halt - clears endpoint halt, and resets toggle
- * @ep:the bulk or interrupt endpoint being reset
- *
- * Use this when responding to the standard usb "set interface" request,
- * for endpoints that aren't reconfigured, after clearing any other state
- * in the endpoint's i/o queue.
- *
- * Returns zero, or a negative error code.  On success, this call clears
- * the underlying hardware state reflecting endpoint halt and data toggle.
- * Note that some hardware can't support this request (like pxa2xx_udc),
- * and accordingly can't correctly implement interface altsettings.
- */
+{ return 0; }
 static inline int usb_ep_clear_halt(struct usb_ep *ep)
-{
-	return ep->ops->set_halt(ep, 0);
-}
-
-/**
- * usb_ep_set_wedge - sets the halt feature and ignores clear requests
- * @ep: the endpoint being wedged
- *
- * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
- * requests. If the gadget driver clears the halt status, it will
- * automatically unwedge the endpoint.
- *
- * Returns zero on success, else negative errno.
- */
-static inline int
-usb_ep_set_wedge(struct usb_ep *ep)
-{
-	if (ep->ops->set_wedge)
-		return ep->ops->set_wedge(ep);
-	else
-		return ep->ops->set_halt(ep, 1);
-}
-
-/**
- * usb_ep_fifo_status - returns number of bytes in fifo, or error
- * @ep: the endpoint whose fifo status is being checked.
- *
- * FIFO endpoints may have "unclaimed data" in them in certain cases,
- * such as after aborted transfers.  Hosts may not have collected all
- * the IN data written by the gadget driver (and reported by a request
- * completion).  The gadget driver may not have collected all the data
- * written OUT to it by the host.  Drivers that need precise handling for
- * fault reporting or recovery may need to use this call.
- *
- * This returns the number of such bytes in the fifo, or a negative
- * errno if the endpoint doesn't use a FIFO or doesn't support such
- * precise handling.
- */
+{ return 0; }
+static inline int usb_ep_set_wedge(struct usb_ep *ep)
+{ return 0; }
 static inline int usb_ep_fifo_status(struct usb_ep *ep)
-{
-	if (ep->ops->fifo_status)
-		return ep->ops->fifo_status(ep);
-	else
-		return -EOPNOTSUPP;
-}
-
-/**
- * usb_ep_fifo_flush - flushes contents of a fifo
- * @ep: the endpoint whose fifo is being flushed.
- *
- * This call may be used to flush the "unclaimed data" that may exist in
- * an endpoint fifo after abnormal transaction terminations.  The call
- * must never be used except when endpoint is not being used for any
- * protocol translation.
- */
+{ return 0; }
 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
-{
-	if (ep->ops->fifo_flush)
-		ep->ops->fifo_flush(ep);
-}
-
+{ }
+#endif /* USB_GADGET */
 
 /*-------------------------------------------------------------------------*/
 
@@ -760,251 +502,19 @@ static inline int gadget_is_otg(struct usb_gadget *g)
 #endif
 }
 
-/**
- * usb_gadget_frame_number - returns the current frame number
- * @gadget: controller that reports the frame number
- *
- * Returns the usb frame number, normally eleven bits from a SOF packet,
- * or negative errno if this device doesn't support this capability.
- */
-static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
-{
-	return gadget->ops->get_frame(gadget);
-}
-
-/**
- * usb_gadget_wakeup - tries to wake up the host connected to this gadget
- * @gadget: controller used to wake up the host
- *
- * Returns zero on success, else negative error code if the hardware
- * doesn't support such attempts, or its support has not been enabled
- * by the usb host.  Drivers must return device descriptors that report
- * their ability to support this, or hosts won't enable it.
- *
- * This may also try to use SRP to wake the host and start enumeration,
- * even if OTG isn't otherwise in use.  OTG devices may also start
- * remote wakeup even when hosts don't explicitly enable it.
- */
-static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->wakeup)
-		return -EOPNOTSUPP;
-	return gadget->ops->wakeup(gadget);
-}
-
-/**
- * usb_gadget_set_selfpowered - sets the device selfpowered feature.
- * @gadget:the device being declared as self-powered
- *
- * this affects the device status reported by the hardware driver
- * to reflect that it now has a local power supply.
- *
- * returns zero on success, else negative errno.
- */
-static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->set_selfpowered)
-		return -EOPNOTSUPP;
-	return gadget->ops->set_selfpowered(gadget, 1);
-}
-
-/**
- * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
- * @gadget:the device being declared as bus-powered
- *
- * this affects the device status reported by the hardware driver.
- * some hardware may not support bus-powered operation, in which
- * case this feature's value can never change.
- *
- * returns zero on success, else negative errno.
- */
-static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->set_selfpowered)
-		return -EOPNOTSUPP;
-	return gadget->ops->set_selfpowered(gadget, 0);
-}
-
-/**
- * usb_gadget_vbus_connect - Notify controller that VBUS is powered
- * @gadget:The device which now has VBUS power.
- * Context: can sleep
- *
- * This call is used by a driver for an external transceiver (or GPIO)
- * that detects a VBUS power session starting.  Common responses include
- * resuming the controller, activating the D+ (or D-) pullup to let the
- * host detect that a USB device is attached, and starting to draw power
- * (8mA or possibly more, especially after SET_CONFIGURATION).
- *
- * Returns zero on success, else negative errno.
- */
-static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->vbus_session)
-		return -EOPNOTSUPP;
-	return gadget->ops->vbus_session(gadget, 1);
-}
-
-/**
- * usb_gadget_vbus_draw - constrain controller's VBUS power usage
- * @gadget:The device whose VBUS usage is being described
- * @mA:How much current to draw, in milliAmperes.  This should be twice
- *	the value listed in the configuration descriptor bMaxPower field.
- *
- * This call is used by gadget drivers during SET_CONFIGURATION calls,
- * reporting how much power the device may consume.  For example, this
- * could affect how quickly batteries are recharged.
- *
- * Returns zero on success, else negative errno.
- */
-static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
-{
-	if (!gadget->ops->vbus_draw)
-		return -EOPNOTSUPP;
-	return gadget->ops->vbus_draw(gadget, mA);
-}
-
-/**
- * usb_gadget_vbus_disconnect - notify controller about VBUS session end
- * @gadget:the device whose VBUS supply is being described
- * Context: can sleep
- *
- * This call is used by a driver for an external transceiver (or GPIO)
- * that detects a VBUS power session ending.  Common responses include
- * reversing everything done in usb_gadget_vbus_connect().
- *
- * Returns zero on success, else negative errno.
- */
-static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->vbus_session)
-		return -EOPNOTSUPP;
-	return gadget->ops->vbus_session(gadget, 0);
-}
-
-/**
- * usb_gadget_connect - software-controlled connect to USB host
- * @gadget:the peripheral being connected
- *
- * Enables the D+ (or potentially D-) pullup.  The host will start
- * enumerating this gadget when the pullup is active and a VBUS session
- * is active (the link is powered).  This pullup is always enabled unless
- * usb_gadget_disconnect() has been used to disable it.
- *
- * Returns zero on success, else negative errno.
- */
-static inline int usb_gadget_connect(struct usb_gadget *gadget)
-{
-	int ret;
-
-	if (!gadget->ops->pullup)
-		return -EOPNOTSUPP;
-
-	if (gadget->deactivated) {
-		/*
-		 * If gadget is deactivated we only save new state.
-		 * Gadget will be connected automatically after activation.
-		 */
-		gadget->connected = true;
-		return 0;
-	}
-
-	ret = gadget->ops->pullup(gadget, 1);
-	if (!ret)
-		gadget->connected = 1;
-	return ret;
-}
-
-/**
- * usb_gadget_disconnect - software-controlled disconnect from USB host
- * @gadget:the peripheral being disconnected
- *
- * Disables the D+ (or potentially D-) pullup, which the host may see
- * as a disconnect (when a VBUS session is active).  Not all systems
- * support software pullup controls.
- *
- * Returns zero on success, else negative errno.
- */
-static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
-{
-	int ret;
-
-	if (!gadget->ops->pullup)
-		return -EOPNOTSUPP;
-
-	if (gadget->deactivated) {
-		/*
-		 * If gadget is deactivated we only save new state.
-		 * Gadget will stay disconnected after activation.
-		 */
-		gadget->connected = false;
-		return 0;
-	}
-
-	ret = gadget->ops->pullup(gadget, 0);
-	if (!ret)
-		gadget->connected = 0;
-	return ret;
-}
-
-/**
- * usb_gadget_deactivate - deactivate function which is not ready to work
- * @gadget: the peripheral being deactivated
- *
- * This routine may be used during the gadget driver bind() call to prevent
- * the peripheral from ever being visible to the USB host, unless later
- * usb_gadget_activate() is called.  For example, user mode components may
- * need to be activated before the system can talk to hosts.
- *
- * Returns zero on success, else negative errno.
- */
-static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
-{
-	int ret;
-
-	if (gadget->deactivated)
-		return 0;
-
-	if (gadget->connected) {
-		ret = usb_gadget_disconnect(gadget);
-		if (ret)
-			return ret;
-		/*
-		 * If gadget was being connected before deactivation, we want
-		 * to reconnect it in usb_gadget_activate().
-		 */
-		gadget->connected = true;
-	}
-	gadget->deactivated = true;
-
-	return 0;
-}
-
-/**
- * usb_gadget_activate - activate function which is not ready to work
- * @gadget: the peripheral being activated
- *
- * This routine activates gadget which was previously deactivated with
- * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
- *
- * Returns zero on success, else negative errno.
- */
-static inline int usb_gadget_activate(struct usb_gadget *gadget)
-{
-	if (!gadget->deactivated)
-		return 0;
-
-	gadget->deactivated = false;
-
-	/*
-	 * If gadget has been connected before deactivation, or became connected
-	 * while it was being deactivated, we call usb_gadget_connect().
-	 */
-	if (gadget->connected)
-		return usb_gadget_connect(gadget);
+/*-------------------------------------------------------------------------*/
 
-	return 0;
-}
+int usb_gadget_frame_number(struct usb_gadget *gadget);
+int usb_gadget_wakeup(struct usb_gadget *gadget);
+int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
+int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
+int usb_gadget_vbus_connect(struct usb_gadget *gadget);
+int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
+int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
+int usb_gadget_connect(struct usb_gadget *gadget);
+int usb_gadget_disconnect(struct usb_gadget *gadget);
+int usb_gadget_deactivate(struct usb_gadget *gadget);
+int usb_gadget_activate(struct usb_gadget *gadget);
 
 /*-------------------------------------------------------------------------*/
 


-- 
balbi

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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Peter Chen]

On Tue, Jun 07, 2016 at 01:22:37PM +0300, Felipe Balbi wrote:
> 
> Hi,
> 
> Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
> >> >> > kbuild test robot <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:
> >> >> >> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git testing/next
> >> >> >> head:   89fe2b5ab11cdf6a67d4492d893e70e330aa7060
> >> >> >> commit: 231b31ca34485552fe27e67dc6d30d06079c7648 [64/67] usb: gadget: move gadget API functions to udc-core
> >> >> >> config: x86_64-randconfig-s1-06061834 (attached as .config)
> >> >> >> compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
> >> >> >> reproduce:
> >> >> >>         git checkout 231b31ca34485552fe27e67dc6d30d06079c7648
> >> >> >>         # save the attached .config to linux build tree
> >> >> >>         make ARCH=x86_64 
> >> >> >>
> >> >> >> All errors (new ones prefixed by >>):
> >> >> >>
> >> >> >>    drivers/built-in.o: In function `nop_set_peripheral':
> >> >> >>>> phy-generic.c:(.text+0x14423f): undefined reference to `usb_gadget_vbus_connect'
> >> >> >>    drivers/built-in.o: In function `nop_gpio_vbus_thread':
> >> >> >>>> phy-generic.c:(.text+0x144742): undefined reference to `usb_gadget_vbus_disconnect'
> >> >> >
> >> >> > oh yeah, I have to fix this. I'll do it now.
> >> >> 
> >> >> In order to fix this, I'll have to add something like below:
> >> >> 
> >> >> diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
> >> >> index 3644a3500b70..bd67e4ac4b61 100644
> >> >> --- a/drivers/usb/chipidea/Kconfig
> >> >> +++ b/drivers/usb/chipidea/Kconfig
> >> >> @@ -19,6 +19,7 @@ config USB_CHIPIDEA_OF
> >> >>  config USB_CHIPIDEA_PCI
> >> >>  	tristate
> >> >>  	depends on PCI
> >> >> +	depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
> >> >>  	depends on NOP_USB_XCEIV
> >> >>  	default USB_CHIPIDEA
> >> >
> >> > Hi Felipe,
> >> >
> >> > It causes any drivers which use symbols from gadget.h needs to build
> >> > USB_GADGET even it only wants to be host function. Any significant
> >> > benefits after moving it to udc-core.c?
> >> 
> >> why is a host-only function calling into the gadget API?
> >> 
> >
> > Well, Just like this case, the chipidea driver can be configured host
> > mode only, but it still uses generic phy.
> 
> then we should allow for PHYs to not depend on the Gadget API, right?

But you know it is not easy. The difficulty for gadget to do that is vbus and
pull dp, these two may be used by other subsystems, eg, vbus may be used
at PHY driver, dual-role switch driver, etc. The pull dp may be used at
USB charger driver, the secondary charger detection needs to pull up dp
for some charger designs.

See current kernel doc, it also says that.

	/**
	 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
	 * @gadget:The device which now has VBUS power.
	 * Context: can sleep
	 *
	 * This call is used by a driver for an external transceiver (or GPIO)
	 * that detects a VBUS power session starting.  Common responses include
	 * resuming the controller, activating the D+ (or D-) pullup to let the
	 * host detect that a USB device is attached, and starting to draw power
	 * (8mA or possibly more, especially after SET_CONFIGURATION).
	 *
	 * Returns zero on success, else negative errno.
	 */
	static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
	{
		if (!gadget->ops->vbus_session)
			return -EOPNOTSUPP;
		return gadget->ops->vbus_session(gadget, 1);
	}

See current situations:

b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_vbus_connect"
./drivers/phy/phy-twl4030-usb.c:559:		 * REVISIT usb_gadget_vbus_connect(...) as needed, ditto
./drivers/usb/phy/phy-gpio-vbus-usb.c:126:		usb_gadget_vbus_connect(gpio_vbus->phy.otg->gadget);
./drivers/usb/phy/phy-tahvo.c:89:				usb_gadget_vbus_connect(tu->phy.otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:929:	usb_gadget_vbus_connect(isp->phy.otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:1466:		usb_gadget_vbus_connect(otg->gadget);
./drivers/usb/phy/phy-generic.c:122:			usb_gadget_vbus_connect(otg->gadget);
./drivers/usb/phy/phy-generic.c:190:		usb_gadget_vbus_connect(gadget);
./drivers/usb/phy/phy-msm-usb.c:783:		usb_gadget_vbus_connect(phy->otg->gadget);
./drivers/usb/phy/phy-mv-usb.c:234:		usb_gadget_vbus_connect(otg->gadget);
./drivers/usb/chipidea/otg.c:133:		usb_gadget_vbus_connect(&ci->gadget);
./drivers/usb/chipidea/otg.c:138:		usb_gadget_vbus_connect(&ci->gadget);
./drivers/usb/chipidea/udc.c:1964:		usb_gadget_vbus_connect(&ci->gadget);
./drivers/usb/chipidea/otg_fsm.c:567:		usb_gadget_vbus_connect(&ci->gadget);
b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_vbus_disconnect"
./drivers/usb/phy/phy-gpio-vbus-usb.c:145:		usb_gadget_vbus_disconnect(gpio_vbus->phy.otg->gadget);
./drivers/usb/phy/phy-gpio-vbus-usb.c:200:		usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-tahvo.c:108:				usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
./drivers/usb/phy/phy-tahvo.c:165:		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
./drivers/usb/phy/phy-tahvo.c:175:		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:312:	return usb_gadget_vbus_disconnect(isp->phy.otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:989:				usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:1342:		usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-generic.c:133:			usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-fsl-usb.c:622:		usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-msm-usb.c:786:		usb_gadget_vbus_disconnect(phy->otg->gadget);
./drivers/usb/phy/phy-mv-usb.c:236:		usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/chipidea/otg.c:140:		usb_gadget_vbus_disconnect(&ci->gadget);
./drivers/usb/chipidea/otg_fsm.c:569:		usb_gadget_vbus_disconnect(&ci->gadget);
b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_connect"
./drivers/power/isp1704_charger.c:272:				usb_gadget_connect(isp->phy->otg->gadget);
./drivers/usb/gadget/udc/fsl_udc_core.c:1215: * this func is used by usb_gadget_connect/disconnet
./drivers/usb/gadget/udc/udc-core.c:262:		usb_gadget_connect(udc->gadget);
./drivers/usb/gadget/udc/udc-core.c:671:		usb_gadget_connect(udc->gadget);
./drivers/usb/chipidea/udc.c:1593: * this func is used by usb_gadget_connect/disconnet
b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_disconnect"
./drivers/power/isp1704_charger.c:302:			usb_gadget_disconnect(isp->phy->otg->gadget);
./drivers/power/isp1704_charger.c:504:		usb_gadget_disconnect(isp->phy->otg->gadget);
./drivers/usb/gadget/udc/udc-core.c:264:		usb_gadget_disconnect(udc->gadget);
./drivers/usb/gadget/udc/udc-core.c:502:	usb_gadget_disconnect(udc->gadget);
./drivers/usb/gadget/udc/udc-core.c:673:		usb_gadget_disconnect(udc->gadget);
./drivers/usb/gadget/composite.c:974: * Drivers must call usb_gadget_disconnect before calling this function
./drivers/usb/gadget/composite.c:2296: * the host, unless one of its components invokes usb_gadget_disconnect()

Would you consider only keeps vbus and pull dp API at gadget.h, and move
out others gadget APIs which is dedicated for gadget function?

Peter

> 
> > Besides, we have some common code which handles vbus status, this code
> > will be built even at host-only mode, but will not be called since the
> > runtime condition is not satisfied, eg, dr_mode, device role at
> > register.
> 
> driver shouldn't depend on the gadget API if it's not built with Gadget
> support. Look at dwc3 for instance. All gadget API-related code is
> stashed in ep0.c and gadget.c, but those only get built if the driver
> was built with gadget support:
> 
> Kconfig
> =======
> 
> 8<------------------------------------------------------------------------
> 
> choice
> 	bool "DWC3 Mode Selection"
> 	default USB_DWC3_DUAL_ROLE if (USB && USB_GADGET)
> 	default USB_DWC3_HOST if (USB && !USB_GADGET)
> 	default USB_DWC3_GADGET if (!USB && USB_GADGET)
> 
> config USB_DWC3_HOST
> 	bool "Host only mode"
> 	depends on USB=y || USB=USB_DWC3
> 	help
> 	  Select this when you want to use DWC3 in host mode only,
> 	  thereby the gadget feature will be regressed.
> 
> config USB_DWC3_GADGET
> 	bool "Gadget only mode"
> 	depends on USB_GADGET=y || USB_GADGET=USB_DWC3
> 	help
> 	  Select this when you want to use DWC3 in gadget mode only,
> 	  thereby the host feature will be regressed.
> 
> config USB_DWC3_DUAL_ROLE
> 	bool "Dual Role mode"
> 	depends on ((USB=y || USB=USB_DWC3) && (USB_GADGET=y || USB_GADGET=USB_DWC3))
> 	help
> 	  This is the default mode of working of DWC3 controller where
> 	  both host and gadget features are enabled.
> 
> endchoice
> 
> 8<------------------------------------------------------------------------
> 
> 
> Makefile
> ========
> 
> 8<------------------------------------------------------------------------
> 
> ifneq ($(filter y,$(CONFIG_USB_DWC3_GADGET) $(CONFIG_USB_DWC3_DUAL_ROLE)),)
> 	dwc3-y				+= gadget.o ep0.o
> endif
> 
> 8<------------------------------------------------------------------------
> 
> In any case, here's a better version of this patch:
> 
> commit 9062bc60311d0a4bbe84e2aa3ec7c2cba06356e4
> Author: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Date:   Tue May 31 13:07:47 2016 +0300
> 
>     usb: gadget: move gadget API functions to udc-core
>     
>     instead of defining all functions as static inlines,
>     let's move them to udc-core and export them with
>     EXPORT_SYMBOL_GPL, that way we can make sure that
>     only GPL drivers will use them.
>     
>     As a side effect, it'll be nicer to add tracepoints
>     to the gadget API.
>     
>     While at that, also fix Kconfig dependencies to
>     avoid randconfig build failures.
>     
>     Signed-off-by: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> 
> diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
> index 6e8300d6a737..d2f28bb6dbda 100644
> --- a/drivers/usb/gadget/udc/udc-core.c
> +++ b/drivers/usb/gadget/udc/udc-core.c
> @@ -59,6 +59,579 @@ static int udc_bind_to_driver(struct usb_udc *udc,
>  
>  /* ------------------------------------------------------------------------- */
>  
> +/**
> + * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
> + * @ep:the endpoint being configured
> + * @maxpacket_limit:value of maximum packet size limit
> + *
> + * This function should be used only in UDC drivers to initialize endpoint
> + * (usually in probe function).
> + */
> +void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
> +					      unsigned maxpacket_limit)
> +{
> +	ep->maxpacket_limit = maxpacket_limit;
> +	ep->maxpacket = maxpacket_limit;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
> +
> +/**
> + * usb_ep_enable - configure endpoint, making it usable
> + * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
> + *	drivers discover endpoints through the ep_list of a usb_gadget.
> + *
> + * When configurations are set, or when interface settings change, the driver
> + * will enable or disable the relevant endpoints.  while it is enabled, an
> + * endpoint may be used for i/o until the driver receives a disconnect() from
> + * the host or until the endpoint is disabled.
> + *
> + * the ep0 implementation (which calls this routine) must ensure that the
> + * hardware capabilities of each endpoint match the descriptor provided
> + * for it.  for example, an endpoint named "ep2in-bulk" would be usable
> + * for interrupt transfers as well as bulk, but it likely couldn't be used
> + * for iso transfers or for endpoint 14.  some endpoints are fully
> + * configurable, with more generic names like "ep-a".  (remember that for
> + * USB, "in" means "towards the USB master".)
> + *
> + * returns zero, or a negative error code.
> + */
> +int usb_ep_enable(struct usb_ep *ep)
> +{
> +	int ret;
> +
> +	if (ep->enabled)
> +		return 0;
> +
> +	ret = ep->ops->enable(ep, ep->desc);
> +	if (ret)
> +		return ret;
> +
> +	ep->enabled = true;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_enable);
> +
> +/**
> + * usb_ep_disable - endpoint is no longer usable
> + * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
> + *
> + * no other task may be using this endpoint when this is called.
> + * any pending and uncompleted requests will complete with status
> + * indicating disconnect (-ESHUTDOWN) before this call returns.
> + * gadget drivers must call usb_ep_enable() again before queueing
> + * requests to the endpoint.
> + *
> + * returns zero, or a negative error code.
> + */
> +int usb_ep_disable(struct usb_ep *ep)
> +{
> +	int ret;
> +
> +	if (!ep->enabled)
> +		return 0;
> +
> +	ret = ep->ops->disable(ep);
> +	if (ret)
> +		return ret;
> +
> +	ep->enabled = false;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_disable);
> +
> +/**
> + * usb_ep_alloc_request - allocate a request object to use with this endpoint
> + * @ep:the endpoint to be used with with the request
> + * @gfp_flags:GFP_* flags to use
> + *
> + * Request objects must be allocated with this call, since they normally
> + * need controller-specific setup and may even need endpoint-specific
> + * resources such as allocation of DMA descriptors.
> + * Requests may be submitted with usb_ep_queue(), and receive a single
> + * completion callback.  Free requests with usb_ep_free_request(), when
> + * they are no longer needed.
> + *
> + * Returns the request, or null if one could not be allocated.
> + */
> +struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
> +						       gfp_t gfp_flags)
> +{
> +	return ep->ops->alloc_request(ep, gfp_flags);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
> +
> +/**
> + * usb_ep_free_request - frees a request object
> + * @ep:the endpoint associated with the request
> + * @req:the request being freed
> + *
> + * Reverses the effect of usb_ep_alloc_request().
> + * Caller guarantees the request is not queued, and that it will
> + * no longer be requeued (or otherwise used).
> + */
> +void usb_ep_free_request(struct usb_ep *ep,
> +				       struct usb_request *req)
> +{
> +	ep->ops->free_request(ep, req);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_free_request);
> +
> +/**
> + * usb_ep_queue - queues (submits) an I/O request to an endpoint.
> + * @ep:the endpoint associated with the request
> + * @req:the request being submitted
> + * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
> + *	pre-allocate all necessary memory with the request.
> + *
> + * This tells the device controller to perform the specified request through
> + * that endpoint (reading or writing a buffer).  When the request completes,
> + * including being canceled by usb_ep_dequeue(), the request's completion
> + * routine is called to return the request to the driver.  Any endpoint
> + * (except control endpoints like ep0) may have more than one transfer
> + * request queued; they complete in FIFO order.  Once a gadget driver
> + * submits a request, that request may not be examined or modified until it
> + * is given back to that driver through the completion callback.
> + *
> + * Each request is turned into one or more packets.  The controller driver
> + * never merges adjacent requests into the same packet.  OUT transfers
> + * will sometimes use data that's already buffered in the hardware.
> + * Drivers can rely on the fact that the first byte of the request's buffer
> + * always corresponds to the first byte of some USB packet, for both
> + * IN and OUT transfers.
> + *
> + * Bulk endpoints can queue any amount of data; the transfer is packetized
> + * automatically.  The last packet will be short if the request doesn't fill it
> + * out completely.  Zero length packets (ZLPs) should be avoided in portable
> + * protocols since not all usb hardware can successfully handle zero length
> + * packets.  (ZLPs may be explicitly written, and may be implicitly written if
> + * the request 'zero' flag is set.)  Bulk endpoints may also be used
> + * for interrupt transfers; but the reverse is not true, and some endpoints
> + * won't support every interrupt transfer.  (Such as 768 byte packets.)
> + *
> + * Interrupt-only endpoints are less functional than bulk endpoints, for
> + * example by not supporting queueing or not handling buffers that are
> + * larger than the endpoint's maxpacket size.  They may also treat data
> + * toggle differently.
> + *
> + * Control endpoints ... after getting a setup() callback, the driver queues
> + * one response (even if it would be zero length).  That enables the
> + * status ack, after transferring data as specified in the response.  Setup
> + * functions may return negative error codes to generate protocol stalls.
> + * (Note that some USB device controllers disallow protocol stall responses
> + * in some cases.)  When control responses are deferred (the response is
> + * written after the setup callback returns), then usb_ep_set_halt() may be
> + * used on ep0 to trigger protocol stalls.  Depending on the controller,
> + * it may not be possible to trigger a status-stage protocol stall when the
> + * data stage is over, that is, from within the response's completion
> + * routine.
> + *
> + * For periodic endpoints, like interrupt or isochronous ones, the usb host
> + * arranges to poll once per interval, and the gadget driver usually will
> + * have queued some data to transfer at that time.
> + *
> + * Returns zero, or a negative error code.  Endpoints that are not enabled
> + * report errors; errors will also be
> + * reported when the usb peripheral is disconnected.
> + */
> +int usb_ep_queue(struct usb_ep *ep,
> +			       struct usb_request *req, gfp_t gfp_flags)
> +{
> +	if (WARN_ON_ONCE(!ep->enabled && ep->address))
> +		return -ESHUTDOWN;
> +
> +	return ep->ops->queue(ep, req, gfp_flags);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_queue);
> +
> +/**
> + * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
> + * @ep:the endpoint associated with the request
> + * @req:the request being canceled
> + *
> + * If the request is still active on the endpoint, it is dequeued and its
> + * completion routine is called (with status -ECONNRESET); else a negative
> + * error code is returned. This is guaranteed to happen before the call to
> + * usb_ep_dequeue() returns.
> + *
> + * Note that some hardware can't clear out write fifos (to unlink the request
> + * at the head of the queue) except as part of disconnecting from usb. Such
> + * restrictions prevent drivers from supporting configuration changes,
> + * even to configuration zero (a "chapter 9" requirement).
> + */
> +int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
> +{
> +	return ep->ops->dequeue(ep, req);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_dequeue);
> +
> +/**
> + * usb_ep_set_halt - sets the endpoint halt feature.
> + * @ep: the non-isochronous endpoint being stalled
> + *
> + * Use this to stall an endpoint, perhaps as an error report.
> + * Except for control endpoints,
> + * the endpoint stays halted (will not stream any data) until the host
> + * clears this feature; drivers may need to empty the endpoint's request
> + * queue first, to make sure no inappropriate transfers happen.
> + *
> + * Note that while an endpoint CLEAR_FEATURE will be invisible to the
> + * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
> + * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
> + * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
> + *
> + * Returns zero, or a negative error code.  On success, this call sets
> + * underlying hardware state that blocks data transfers.
> + * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
> + * transfer requests are still queued, or if the controller hardware
> + * (usually a FIFO) still holds bytes that the host hasn't collected.
> + */
> +int usb_ep_set_halt(struct usb_ep *ep)
> +{
> +	return ep->ops->set_halt(ep, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_halt);
> +
> +/**
> + * usb_ep_clear_halt - clears endpoint halt, and resets toggle
> + * @ep:the bulk or interrupt endpoint being reset
> + *
> + * Use this when responding to the standard usb "set interface" request,
> + * for endpoints that aren't reconfigured, after clearing any other state
> + * in the endpoint's i/o queue.
> + *
> + * Returns zero, or a negative error code.  On success, this call clears
> + * the underlying hardware state reflecting endpoint halt and data toggle.
> + * Note that some hardware can't support this request (like pxa2xx_udc),
> + * and accordingly can't correctly implement interface altsettings.
> + */
> +int usb_ep_clear_halt(struct usb_ep *ep)
> +{
> +	return ep->ops->set_halt(ep, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
> +
> +/**
> + * usb_ep_set_wedge - sets the halt feature and ignores clear requests
> + * @ep: the endpoint being wedged
> + *
> + * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
> + * requests. If the gadget driver clears the halt status, it will
> + * automatically unwedge the endpoint.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_ep_set_wedge(struct usb_ep *ep)
> +{
> +	if (ep->ops->set_wedge)
> +		return ep->ops->set_wedge(ep);
> +	else
> +		return ep->ops->set_halt(ep, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
> +
> +/**
> + * usb_ep_fifo_status - returns number of bytes in fifo, or error
> + * @ep: the endpoint whose fifo status is being checked.
> + *
> + * FIFO endpoints may have "unclaimed data" in them in certain cases,
> + * such as after aborted transfers.  Hosts may not have collected all
> + * the IN data written by the gadget driver (and reported by a request
> + * completion).  The gadget driver may not have collected all the data
> + * written OUT to it by the host.  Drivers that need precise handling for
> + * fault reporting or recovery may need to use this call.
> + *
> + * This returns the number of such bytes in the fifo, or a negative
> + * errno if the endpoint doesn't use a FIFO or doesn't support such
> + * precise handling.
> + */
> +int usb_ep_fifo_status(struct usb_ep *ep)
> +{
> +	if (ep->ops->fifo_status)
> +		return ep->ops->fifo_status(ep);
> +	else
> +		return -EOPNOTSUPP;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
> +
> +/**
> + * usb_ep_fifo_flush - flushes contents of a fifo
> + * @ep: the endpoint whose fifo is being flushed.
> + *
> + * This call may be used to flush the "unclaimed data" that may exist in
> + * an endpoint fifo after abnormal transaction terminations.  The call
> + * must never be used except when endpoint is not being used for any
> + * protocol translation.
> + */
> +void usb_ep_fifo_flush(struct usb_ep *ep)
> +{
> +	if (ep->ops->fifo_flush)
> +		ep->ops->fifo_flush(ep);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
> +
> +/* ------------------------------------------------------------------------- */
> +
> +/**
> + * usb_gadget_frame_number - returns the current frame number
> + * @gadget: controller that reports the frame number
> + *
> + * Returns the usb frame number, normally eleven bits from a SOF packet,
> + * or negative errno if this device doesn't support this capability.
> + */
> +int usb_gadget_frame_number(struct usb_gadget *gadget)
> +{
> +	return gadget->ops->get_frame(gadget);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
> +
> +/**
> + * usb_gadget_wakeup - tries to wake up the host connected to this gadget
> + * @gadget: controller used to wake up the host
> + *
> + * Returns zero on success, else negative error code if the hardware
> + * doesn't support such attempts, or its support has not been enabled
> + * by the usb host.  Drivers must return device descriptors that report
> + * their ability to support this, or hosts won't enable it.
> + *
> + * This may also try to use SRP to wake the host and start enumeration,
> + * even if OTG isn't otherwise in use.  OTG devices may also start
> + * remote wakeup even when hosts don't explicitly enable it.
> + */
> +int usb_gadget_wakeup(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->wakeup)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->wakeup(gadget);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
> +
> +/**
> + * usb_gadget_set_selfpowered - sets the device selfpowered feature.
> + * @gadget:the device being declared as self-powered
> + *
> + * this affects the device status reported by the hardware driver
> + * to reflect that it now has a local power supply.
> + *
> + * returns zero on success, else negative errno.
> + */
> +int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->set_selfpowered)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->set_selfpowered(gadget, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
> +
> +/**
> + * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
> + * @gadget:the device being declared as bus-powered
> + *
> + * this affects the device status reported by the hardware driver.
> + * some hardware may not support bus-powered operation, in which
> + * case this feature's value can never change.
> + *
> + * returns zero on success, else negative errno.
> + */
> +int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->set_selfpowered)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->set_selfpowered(gadget, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
> +
> +/**
> + * usb_gadget_vbus_connect - Notify controller that VBUS is powered
> + * @gadget:The device which now has VBUS power.
> + * Context: can sleep
> + *
> + * This call is used by a driver for an external transceiver (or GPIO)
> + * that detects a VBUS power session starting.  Common responses include
> + * resuming the controller, activating the D+ (or D-) pullup to let the
> + * host detect that a USB device is attached, and starting to draw power
> + * (8mA or possibly more, especially after SET_CONFIGURATION).
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_connect(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->vbus_session)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_session(gadget, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
> +
> +/**
> + * usb_gadget_vbus_draw - constrain controller's VBUS power usage
> + * @gadget:The device whose VBUS usage is being described
> + * @mA:How much current to draw, in milliAmperes.  This should be twice
> + *	the value listed in the configuration descriptor bMaxPower field.
> + *
> + * This call is used by gadget drivers during SET_CONFIGURATION calls,
> + * reporting how much power the device may consume.  For example, this
> + * could affect how quickly batteries are recharged.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
> +{
> +	if (!gadget->ops->vbus_draw)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_draw(gadget, mA);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
> +
> +/**
> + * usb_gadget_vbus_disconnect - notify controller about VBUS session end
> + * @gadget:the device whose VBUS supply is being described
> + * Context: can sleep
> + *
> + * This call is used by a driver for an external transceiver (or GPIO)
> + * that detects a VBUS power session ending.  Common responses include
> + * reversing everything done in usb_gadget_vbus_connect().
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->vbus_session)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_session(gadget, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
> +
> +/**
> + * usb_gadget_connect - software-controlled connect to USB host
> + * @gadget:the peripheral being connected
> + *
> + * Enables the D+ (or potentially D-) pullup.  The host will start
> + * enumerating this gadget when the pullup is active and a VBUS session
> + * is active (the link is powered).  This pullup is always enabled unless
> + * usb_gadget_disconnect() has been used to disable it.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_connect(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (!gadget->ops->pullup)
> +		return -EOPNOTSUPP;
> +
> +	if (gadget->deactivated) {
> +		/*
> +		 * If gadget is deactivated we only save new state.
> +		 * Gadget will be connected automatically after activation.
> +		 */
> +		gadget->connected = true;
> +		return 0;
> +	}
> +
> +	ret = gadget->ops->pullup(gadget, 1);
> +	if (!ret)
> +		gadget->connected = 1;
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_connect);
> +
> +/**
> + * usb_gadget_disconnect - software-controlled disconnect from USB host
> + * @gadget:the peripheral being disconnected
> + *
> + * Disables the D+ (or potentially D-) pullup, which the host may see
> + * as a disconnect (when a VBUS session is active).  Not all systems
> + * support software pullup controls.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_disconnect(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (!gadget->ops->pullup)
> +		return -EOPNOTSUPP;
> +
> +	if (gadget->deactivated) {
> +		/*
> +		 * If gadget is deactivated we only save new state.
> +		 * Gadget will stay disconnected after activation.
> +		 */
> +		gadget->connected = false;
> +		return 0;
> +	}
> +
> +	ret = gadget->ops->pullup(gadget, 0);
> +	if (!ret)
> +		gadget->connected = 0;
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
> +
> +/**
> + * usb_gadget_deactivate - deactivate function which is not ready to work
> + * @gadget: the peripheral being deactivated
> + *
> + * This routine may be used during the gadget driver bind() call to prevent
> + * the peripheral from ever being visible to the USB host, unless later
> + * usb_gadget_activate() is called.  For example, user mode components may
> + * need to be activated before the system can talk to hosts.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_deactivate(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (gadget->deactivated)
> +		return 0;
> +
> +	if (gadget->connected) {
> +		ret = usb_gadget_disconnect(gadget);
> +		if (ret)
> +			return ret;
> +		/*
> +		 * If gadget was being connected before deactivation, we want
> +		 * to reconnect it in usb_gadget_activate().
> +		 */
> +		gadget->connected = true;
> +	}
> +	gadget->deactivated = true;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
> +
> +/**
> + * usb_gadget_activate - activate function which is not ready to work
> + * @gadget: the peripheral being activated
> + *
> + * This routine activates gadget which was previously deactivated with
> + * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_activate(struct usb_gadget *gadget)
> +{
> +	if (!gadget->deactivated)
> +		return 0;
> +
> +	gadget->deactivated = false;
> +
> +	/*
> +	 * If gadget has been connected before deactivation, or became connected
> +	 * while it was being deactivated, we call usb_gadget_connect().
> +	 */
> +	if (gadget->connected)
> +		return usb_gadget_connect(gadget);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_activate);
> +
> +/* ------------------------------------------------------------------------- */
> +
>  #ifdef	CONFIG_HAS_DMA
>  
>  int usb_gadget_map_request_by_dev(struct device *dev,
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index d8f5674809e8..2e710a4cca52 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -180,7 +180,7 @@ config USB_EHCI_MXC
>  config USB_EHCI_HCD_OMAP
>  	tristate "EHCI support for OMAP3 and later chips"
>  	depends on ARCH_OMAP
> -	select NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	default y
>  	---help---
>  	  Enables support for the on-chip EHCI controller on
> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
> index c6904742e2aa..ca509448b844 100644
> --- a/drivers/usb/phy/Kconfig
> +++ b/drivers/usb/phy/Kconfig
> @@ -43,7 +43,7 @@ config ISP1301_OMAP
>  config KEYSTONE_USB_PHY
>  	tristate "Keystone USB PHY Driver"
>  	depends on ARCH_KEYSTONE || COMPILE_TEST
> -	select NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	help
>  	  Enable this to support Keystone USB phy. This driver provides
>  	  interface to interact with USB 2.0 and USB 3.0 PHY that is part
> @@ -51,6 +51,7 @@ config KEYSTONE_USB_PHY
>  
>  config NOP_USB_XCEIV
>  	tristate "NOP USB Transceiver Driver"
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, NOP can't be built-in
>  	select USB_PHY
>  	help
>  	  This driver is to be used by all the usb transceiver which are either
> @@ -63,9 +64,9 @@ config AM335X_CONTROL_USB
>  config AM335X_PHY_USB
>  	tristate "AM335x USB PHY Driver"
>  	depends on ARM || COMPILE_TEST
> +	depends on NOP_USB_XCEIV
>  	select USB_PHY
>  	select AM335X_CONTROL_USB
> -	select NOP_USB_XCEIV
>  	select USB_COMMON
>  	help
>  	  This driver provides PHY support for that phy which part for the
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 457651bf45b0..4cfc1ea352bb 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -228,307 +228,49 @@ struct usb_ep {
>  
>  /*-------------------------------------------------------------------------*/
>  
> -/**
> - * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
> - * @ep:the endpoint being configured
> - * @maxpacket_limit:value of maximum packet size limit
> - *
> - * This function should be used only in UDC drivers to initialize endpoint
> - * (usually in probe function).
> - */
> +#if IS_ENABLED(CONFIG_USB_GADGET)
> +void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
> +int usb_ep_enable(struct usb_ep *ep);
> +int usb_ep_disable(struct usb_ep *ep);
> +struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
> +void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
> +int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
> +int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
> +int usb_ep_set_halt(struct usb_ep *ep);
> +int usb_ep_clear_halt(struct usb_ep *ep);
> +int usb_ep_set_wedge(struct usb_ep *ep);
> +int usb_ep_fifo_status(struct usb_ep *ep);
> +void usb_ep_fifo_flush(struct usb_ep *ep);
> +#else
>  static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
> -					      unsigned maxpacket_limit)
> -{
> -	ep->maxpacket_limit = maxpacket_limit;
> -	ep->maxpacket = maxpacket_limit;
> -}
> -
> -/**
> - * usb_ep_enable - configure endpoint, making it usable
> - * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
> - *	drivers discover endpoints through the ep_list of a usb_gadget.
> - *
> - * When configurations are set, or when interface settings change, the driver
> - * will enable or disable the relevant endpoints.  while it is enabled, an
> - * endpoint may be used for i/o until the driver receives a disconnect() from
> - * the host or until the endpoint is disabled.
> - *
> - * the ep0 implementation (which calls this routine) must ensure that the
> - * hardware capabilities of each endpoint match the descriptor provided
> - * for it.  for example, an endpoint named "ep2in-bulk" would be usable
> - * for interrupt transfers as well as bulk, but it likely couldn't be used
> - * for iso transfers or for endpoint 14.  some endpoints are fully
> - * configurable, with more generic names like "ep-a".  (remember that for
> - * USB, "in" means "towards the USB master".)
> - *
> - * returns zero, or a negative error code.
> - */
> +		unsigned maxpacket_limit)
> +{ }
>  static inline int usb_ep_enable(struct usb_ep *ep)
> -{
> -	int ret;
> -
> -	if (ep->enabled)
> -		return 0;
> -
> -	ret = ep->ops->enable(ep, ep->desc);
> -	if (ret)
> -		return ret;
> -
> -	ep->enabled = true;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_ep_disable - endpoint is no longer usable
> - * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
> - *
> - * no other task may be using this endpoint when this is called.
> - * any pending and uncompleted requests will complete with status
> - * indicating disconnect (-ESHUTDOWN) before this call returns.
> - * gadget drivers must call usb_ep_enable() again before queueing
> - * requests to the endpoint.
> - *
> - * returns zero, or a negative error code.
> - */
> +{ return 0; }
>  static inline int usb_ep_disable(struct usb_ep *ep)
> -{
> -	int ret;
> -
> -	if (!ep->enabled)
> -		return 0;
> -
> -	ret = ep->ops->disable(ep);
> -	if (ret)
> -		return ret;
> -
> -	ep->enabled = false;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_ep_alloc_request - allocate a request object to use with this endpoint
> - * @ep:the endpoint to be used with with the request
> - * @gfp_flags:GFP_* flags to use
> - *
> - * Request objects must be allocated with this call, since they normally
> - * need controller-specific setup and may even need endpoint-specific
> - * resources such as allocation of DMA descriptors.
> - * Requests may be submitted with usb_ep_queue(), and receive a single
> - * completion callback.  Free requests with usb_ep_free_request(), when
> - * they are no longer needed.
> - *
> - * Returns the request, or null if one could not be allocated.
> - */
> +{ return 0; }
>  static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
> -						       gfp_t gfp_flags)
> -{
> -	return ep->ops->alloc_request(ep, gfp_flags);
> -}
> -
> -/**
> - * usb_ep_free_request - frees a request object
> - * @ep:the endpoint associated with the request
> - * @req:the request being freed
> - *
> - * Reverses the effect of usb_ep_alloc_request().
> - * Caller guarantees the request is not queued, and that it will
> - * no longer be requeued (or otherwise used).
> - */
> +		gfp_t gfp_flags)
> +{ return NULL; }
>  static inline void usb_ep_free_request(struct usb_ep *ep,
> -				       struct usb_request *req)
> -{
> -	ep->ops->free_request(ep, req);
> -}
> -
> -/**
> - * usb_ep_queue - queues (submits) an I/O request to an endpoint.
> - * @ep:the endpoint associated with the request
> - * @req:the request being submitted
> - * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
> - *	pre-allocate all necessary memory with the request.
> - *
> - * This tells the device controller to perform the specified request through
> - * that endpoint (reading or writing a buffer).  When the request completes,
> - * including being canceled by usb_ep_dequeue(), the request's completion
> - * routine is called to return the request to the driver.  Any endpoint
> - * (except control endpoints like ep0) may have more than one transfer
> - * request queued; they complete in FIFO order.  Once a gadget driver
> - * submits a request, that request may not be examined or modified until it
> - * is given back to that driver through the completion callback.
> - *
> - * Each request is turned into one or more packets.  The controller driver
> - * never merges adjacent requests into the same packet.  OUT transfers
> - * will sometimes use data that's already buffered in the hardware.
> - * Drivers can rely on the fact that the first byte of the request's buffer
> - * always corresponds to the first byte of some USB packet, for both
> - * IN and OUT transfers.
> - *
> - * Bulk endpoints can queue any amount of data; the transfer is packetized
> - * automatically.  The last packet will be short if the request doesn't fill it
> - * out completely.  Zero length packets (ZLPs) should be avoided in portable
> - * protocols since not all usb hardware can successfully handle zero length
> - * packets.  (ZLPs may be explicitly written, and may be implicitly written if
> - * the request 'zero' flag is set.)  Bulk endpoints may also be used
> - * for interrupt transfers; but the reverse is not true, and some endpoints
> - * won't support every interrupt transfer.  (Such as 768 byte packets.)
> - *
> - * Interrupt-only endpoints are less functional than bulk endpoints, for
> - * example by not supporting queueing or not handling buffers that are
> - * larger than the endpoint's maxpacket size.  They may also treat data
> - * toggle differently.
> - *
> - * Control endpoints ... after getting a setup() callback, the driver queues
> - * one response (even if it would be zero length).  That enables the
> - * status ack, after transferring data as specified in the response.  Setup
> - * functions may return negative error codes to generate protocol stalls.
> - * (Note that some USB device controllers disallow protocol stall responses
> - * in some cases.)  When control responses are deferred (the response is
> - * written after the setup callback returns), then usb_ep_set_halt() may be
> - * used on ep0 to trigger protocol stalls.  Depending on the controller,
> - * it may not be possible to trigger a status-stage protocol stall when the
> - * data stage is over, that is, from within the response's completion
> - * routine.
> - *
> - * For periodic endpoints, like interrupt or isochronous ones, the usb host
> - * arranges to poll once per interval, and the gadget driver usually will
> - * have queued some data to transfer at that time.
> - *
> - * Returns zero, or a negative error code.  Endpoints that are not enabled
> - * report errors; errors will also be
> - * reported when the usb peripheral is disconnected.
> - */
> -static inline int usb_ep_queue(struct usb_ep *ep,
> -			       struct usb_request *req, gfp_t gfp_flags)
> -{
> -	if (WARN_ON_ONCE(!ep->enabled && ep->address))
> -		return -ESHUTDOWN;
> -
> -	return ep->ops->queue(ep, req, gfp_flags);
> -}
> -
> -/**
> - * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
> - * @ep:the endpoint associated with the request
> - * @req:the request being canceled
> - *
> - * If the request is still active on the endpoint, it is dequeued and its
> - * completion routine is called (with status -ECONNRESET); else a negative
> - * error code is returned. This is guaranteed to happen before the call to
> - * usb_ep_dequeue() returns.
> - *
> - * Note that some hardware can't clear out write fifos (to unlink the request
> - * at the head of the queue) except as part of disconnecting from usb. Such
> - * restrictions prevent drivers from supporting configuration changes,
> - * even to configuration zero (a "chapter 9" requirement).
> - */
> +		struct usb_request *req)
> +{ }
> +static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
> +		gfp_t gfp_flags)
> +{ return 0; }
>  static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
> -{
> -	return ep->ops->dequeue(ep, req);
> -}
> -
> -/**
> - * usb_ep_set_halt - sets the endpoint halt feature.
> - * @ep: the non-isochronous endpoint being stalled
> - *
> - * Use this to stall an endpoint, perhaps as an error report.
> - * Except for control endpoints,
> - * the endpoint stays halted (will not stream any data) until the host
> - * clears this feature; drivers may need to empty the endpoint's request
> - * queue first, to make sure no inappropriate transfers happen.
> - *
> - * Note that while an endpoint CLEAR_FEATURE will be invisible to the
> - * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
> - * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
> - * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
> - *
> - * Returns zero, or a negative error code.  On success, this call sets
> - * underlying hardware state that blocks data transfers.
> - * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
> - * transfer requests are still queued, or if the controller hardware
> - * (usually a FIFO) still holds bytes that the host hasn't collected.
> - */
> +{ return 0; }
>  static inline int usb_ep_set_halt(struct usb_ep *ep)
> -{
> -	return ep->ops->set_halt(ep, 1);
> -}
> -
> -/**
> - * usb_ep_clear_halt - clears endpoint halt, and resets toggle
> - * @ep:the bulk or interrupt endpoint being reset
> - *
> - * Use this when responding to the standard usb "set interface" request,
> - * for endpoints that aren't reconfigured, after clearing any other state
> - * in the endpoint's i/o queue.
> - *
> - * Returns zero, or a negative error code.  On success, this call clears
> - * the underlying hardware state reflecting endpoint halt and data toggle.
> - * Note that some hardware can't support this request (like pxa2xx_udc),
> - * and accordingly can't correctly implement interface altsettings.
> - */
> +{ return 0; }
>  static inline int usb_ep_clear_halt(struct usb_ep *ep)
> -{
> -	return ep->ops->set_halt(ep, 0);
> -}
> -
> -/**
> - * usb_ep_set_wedge - sets the halt feature and ignores clear requests
> - * @ep: the endpoint being wedged
> - *
> - * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
> - * requests. If the gadget driver clears the halt status, it will
> - * automatically unwedge the endpoint.
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int
> -usb_ep_set_wedge(struct usb_ep *ep)
> -{
> -	if (ep->ops->set_wedge)
> -		return ep->ops->set_wedge(ep);
> -	else
> -		return ep->ops->set_halt(ep, 1);
> -}
> -
> -/**
> - * usb_ep_fifo_status - returns number of bytes in fifo, or error
> - * @ep: the endpoint whose fifo status is being checked.
> - *
> - * FIFO endpoints may have "unclaimed data" in them in certain cases,
> - * such as after aborted transfers.  Hosts may not have collected all
> - * the IN data written by the gadget driver (and reported by a request
> - * completion).  The gadget driver may not have collected all the data
> - * written OUT to it by the host.  Drivers that need precise handling for
> - * fault reporting or recovery may need to use this call.
> - *
> - * This returns the number of such bytes in the fifo, or a negative
> - * errno if the endpoint doesn't use a FIFO or doesn't support such
> - * precise handling.
> - */
> +{ return 0; }
> +static inline int usb_ep_set_wedge(struct usb_ep *ep)
> +{ return 0; }
>  static inline int usb_ep_fifo_status(struct usb_ep *ep)
> -{
> -	if (ep->ops->fifo_status)
> -		return ep->ops->fifo_status(ep);
> -	else
> -		return -EOPNOTSUPP;
> -}
> -
> -/**
> - * usb_ep_fifo_flush - flushes contents of a fifo
> - * @ep: the endpoint whose fifo is being flushed.
> - *
> - * This call may be used to flush the "unclaimed data" that may exist in
> - * an endpoint fifo after abnormal transaction terminations.  The call
> - * must never be used except when endpoint is not being used for any
> - * protocol translation.
> - */
> +{ return 0; }
>  static inline void usb_ep_fifo_flush(struct usb_ep *ep)
> -{
> -	if (ep->ops->fifo_flush)
> -		ep->ops->fifo_flush(ep);
> -}
> -
> +{ }
> +#endif /* USB_GADGET */
>  
>  /*-------------------------------------------------------------------------*/
>  
> @@ -760,251 +502,19 @@ static inline int gadget_is_otg(struct usb_gadget *g)
>  #endif
>  }
>  
> -/**
> - * usb_gadget_frame_number - returns the current frame number
> - * @gadget: controller that reports the frame number
> - *
> - * Returns the usb frame number, normally eleven bits from a SOF packet,
> - * or negative errno if this device doesn't support this capability.
> - */
> -static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
> -{
> -	return gadget->ops->get_frame(gadget);
> -}
> -
> -/**
> - * usb_gadget_wakeup - tries to wake up the host connected to this gadget
> - * @gadget: controller used to wake up the host
> - *
> - * Returns zero on success, else negative error code if the hardware
> - * doesn't support such attempts, or its support has not been enabled
> - * by the usb host.  Drivers must return device descriptors that report
> - * their ability to support this, or hosts won't enable it.
> - *
> - * This may also try to use SRP to wake the host and start enumeration,
> - * even if OTG isn't otherwise in use.  OTG devices may also start
> - * remote wakeup even when hosts don't explicitly enable it.
> - */
> -static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->wakeup)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->wakeup(gadget);
> -}
> -
> -/**
> - * usb_gadget_set_selfpowered - sets the device selfpowered feature.
> - * @gadget:the device being declared as self-powered
> - *
> - * this affects the device status reported by the hardware driver
> - * to reflect that it now has a local power supply.
> - *
> - * returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->set_selfpowered)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->set_selfpowered(gadget, 1);
> -}
> -
> -/**
> - * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
> - * @gadget:the device being declared as bus-powered
> - *
> - * this affects the device status reported by the hardware driver.
> - * some hardware may not support bus-powered operation, in which
> - * case this feature's value can never change.
> - *
> - * returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->set_selfpowered)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->set_selfpowered(gadget, 0);
> -}
> -
> -/**
> - * usb_gadget_vbus_connect - Notify controller that VBUS is powered
> - * @gadget:The device which now has VBUS power.
> - * Context: can sleep
> - *
> - * This call is used by a driver for an external transceiver (or GPIO)
> - * that detects a VBUS power session starting.  Common responses include
> - * resuming the controller, activating the D+ (or D-) pullup to let the
> - * host detect that a USB device is attached, and starting to draw power
> - * (8mA or possibly more, especially after SET_CONFIGURATION).
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->vbus_session)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_session(gadget, 1);
> -}
> -
> -/**
> - * usb_gadget_vbus_draw - constrain controller's VBUS power usage
> - * @gadget:The device whose VBUS usage is being described
> - * @mA:How much current to draw, in milliAmperes.  This should be twice
> - *	the value listed in the configuration descriptor bMaxPower field.
> - *
> - * This call is used by gadget drivers during SET_CONFIGURATION calls,
> - * reporting how much power the device may consume.  For example, this
> - * could affect how quickly batteries are recharged.
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
> -{
> -	if (!gadget->ops->vbus_draw)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_draw(gadget, mA);
> -}
> -
> -/**
> - * usb_gadget_vbus_disconnect - notify controller about VBUS session end
> - * @gadget:the device whose VBUS supply is being described
> - * Context: can sleep
> - *
> - * This call is used by a driver for an external transceiver (or GPIO)
> - * that detects a VBUS power session ending.  Common responses include
> - * reversing everything done in usb_gadget_vbus_connect().
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->vbus_session)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_session(gadget, 0);
> -}
> -
> -/**
> - * usb_gadget_connect - software-controlled connect to USB host
> - * @gadget:the peripheral being connected
> - *
> - * Enables the D+ (or potentially D-) pullup.  The host will start
> - * enumerating this gadget when the pullup is active and a VBUS session
> - * is active (the link is powered).  This pullup is always enabled unless
> - * usb_gadget_disconnect() has been used to disable it.
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_connect(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (!gadget->ops->pullup)
> -		return -EOPNOTSUPP;
> -
> -	if (gadget->deactivated) {
> -		/*
> -		 * If gadget is deactivated we only save new state.
> -		 * Gadget will be connected automatically after activation.
> -		 */
> -		gadget->connected = true;
> -		return 0;
> -	}
> -
> -	ret = gadget->ops->pullup(gadget, 1);
> -	if (!ret)
> -		gadget->connected = 1;
> -	return ret;
> -}
> -
> -/**
> - * usb_gadget_disconnect - software-controlled disconnect from USB host
> - * @gadget:the peripheral being disconnected
> - *
> - * Disables the D+ (or potentially D-) pullup, which the host may see
> - * as a disconnect (when a VBUS session is active).  Not all systems
> - * support software pullup controls.
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (!gadget->ops->pullup)
> -		return -EOPNOTSUPP;
> -
> -	if (gadget->deactivated) {
> -		/*
> -		 * If gadget is deactivated we only save new state.
> -		 * Gadget will stay disconnected after activation.
> -		 */
> -		gadget->connected = false;
> -		return 0;
> -	}
> -
> -	ret = gadget->ops->pullup(gadget, 0);
> -	if (!ret)
> -		gadget->connected = 0;
> -	return ret;
> -}
> -
> -/**
> - * usb_gadget_deactivate - deactivate function which is not ready to work
> - * @gadget: the peripheral being deactivated
> - *
> - * This routine may be used during the gadget driver bind() call to prevent
> - * the peripheral from ever being visible to the USB host, unless later
> - * usb_gadget_activate() is called.  For example, user mode components may
> - * need to be activated before the system can talk to hosts.
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (gadget->deactivated)
> -		return 0;
> -
> -	if (gadget->connected) {
> -		ret = usb_gadget_disconnect(gadget);
> -		if (ret)
> -			return ret;
> -		/*
> -		 * If gadget was being connected before deactivation, we want
> -		 * to reconnect it in usb_gadget_activate().
> -		 */
> -		gadget->connected = true;
> -	}
> -	gadget->deactivated = true;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_gadget_activate - activate function which is not ready to work
> - * @gadget: the peripheral being activated
> - *
> - * This routine activates gadget which was previously deactivated with
> - * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int usb_gadget_activate(struct usb_gadget *gadget)
> -{
> -	if (!gadget->deactivated)
> -		return 0;
> -
> -	gadget->deactivated = false;
> -
> -	/*
> -	 * If gadget has been connected before deactivation, or became connected
> -	 * while it was being deactivated, we call usb_gadget_connect().
> -	 */
> -	if (gadget->connected)
> -		return usb_gadget_connect(gadget);
> +/*-------------------------------------------------------------------------*/
>  
> -	return 0;
> -}
> +int usb_gadget_frame_number(struct usb_gadget *gadget);
> +int usb_gadget_wakeup(struct usb_gadget *gadget);
> +int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
> +int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
> +int usb_gadget_vbus_connect(struct usb_gadget *gadget);
> +int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
> +int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
> +int usb_gadget_connect(struct usb_gadget *gadget);
> +int usb_gadget_disconnect(struct usb_gadget *gadget);
> +int usb_gadget_deactivate(struct usb_gadget *gadget);
> +int usb_gadget_activate(struct usb_gadget *gadget);
>  
>  /*-------------------------------------------------------------------------*/
>  
> 
> 
> -- 
> balbi



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Best Regards,
Peter Chen
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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 52877 bytes --]


Hi,

Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
>> >> > Hi Felipe,
>> >> >
>> >> > It causes any drivers which use symbols from gadget.h needs to build
>> >> > USB_GADGET even it only wants to be host function. Any significant
>> >> > benefits after moving it to udc-core.c?
>> >> 
>> >> why is a host-only function calling into the gadget API?
>> >> 
>> >
>> > Well, Just like this case, the chipidea driver can be configured host
>> > mode only, but it still uses generic phy.
>> 
>> then we should allow for PHYs to not depend on the Gadget API, right?
>
> But you know it is not easy. The difficulty for gadget to do that is
> vbus and pull dp, these two may be used by other subsystems, eg, vbus
> may be used at PHY driver, dual-role switch driver, etc. The pull dp
> may be used at USB charger driver, the secondary charger detection
> needs to pull up dp for some charger designs.

that's fine. And if they really need that, they depend on the Gadget
API. That _is_ something the gadget API defines afterall.

> See current kernel doc, it also says that.
>
> 	/**
> 	 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
> 	 * @gadget:The device which now has VBUS power.
> 	 * Context: can sleep
> 	 *
> 	 * This call is used by a driver for an external transceiver (or GPIO)
> 	 * that detects a VBUS power session starting.  Common responses include
> 	 * resuming the controller, activating the D+ (or D-) pullup to let the
> 	 * host detect that a USB device is attached, and starting to draw power
> 	 * (8mA or possibly more, especially after SET_CONFIGURATION).
> 	 *
> 	 * Returns zero on success, else negative errno.
> 	 */
> 	static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
> 	{
> 		if (!gadget->ops->vbus_session)
> 			return -EOPNOTSUPP;
> 		return gadget->ops->vbus_session(gadget, 1);
> 	}
>
> See current situations:
>
> b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_vbus_connect"
> ./drivers/phy/phy-twl4030-usb.c:559:		 * REVISIT usb_gadget_vbus_connect(...) as needed, ditto
> ./drivers/usb/phy/phy-gpio-vbus-usb.c:126:		usb_gadget_vbus_connect(gpio_vbus->phy.otg->gadget);
> ./drivers/usb/phy/phy-tahvo.c:89:				usb_gadget_vbus_connect(tu->phy.otg->gadget);
> ./drivers/usb/phy/phy-isp1301-omap.c:929:	usb_gadget_vbus_connect(isp->phy.otg->gadget);
> ./drivers/usb/phy/phy-isp1301-omap.c:1466:		usb_gadget_vbus_connect(otg->gadget);
> ./drivers/usb/phy/phy-generic.c:122:			usb_gadget_vbus_connect(otg->gadget);
> ./drivers/usb/phy/phy-generic.c:190:		usb_gadget_vbus_connect(gadget);
> ./drivers/usb/phy/phy-msm-usb.c:783:		usb_gadget_vbus_connect(phy->otg->gadget);
> ./drivers/usb/phy/phy-mv-usb.c:234:		usb_gadget_vbus_connect(otg->gadget);
> ./drivers/usb/chipidea/otg.c:133:		usb_gadget_vbus_connect(&ci->gadget);
> ./drivers/usb/chipidea/otg.c:138:		usb_gadget_vbus_connect(&ci->gadget);
> ./drivers/usb/chipidea/udc.c:1964:		usb_gadget_vbus_connect(&ci->gadget);
> ./drivers/usb/chipidea/otg_fsm.c:567:		usb_gadget_vbus_connect(&ci->gadget);
> b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_vbus_disconnect"
> ./drivers/usb/phy/phy-gpio-vbus-usb.c:145:		usb_gadget_vbus_disconnect(gpio_vbus->phy.otg->gadget);
> ./drivers/usb/phy/phy-gpio-vbus-usb.c:200:		usb_gadget_vbus_disconnect(otg->gadget);
> ./drivers/usb/phy/phy-tahvo.c:108:				usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
> ./drivers/usb/phy/phy-tahvo.c:165:		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
> ./drivers/usb/phy/phy-tahvo.c:175:		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
> ./drivers/usb/phy/phy-isp1301-omap.c:312:	return usb_gadget_vbus_disconnect(isp->phy.otg->gadget);
> ./drivers/usb/phy/phy-isp1301-omap.c:989:				usb_gadget_vbus_disconnect(otg->gadget);
> ./drivers/usb/phy/phy-isp1301-omap.c:1342:		usb_gadget_vbus_disconnect(otg->gadget);
> ./drivers/usb/phy/phy-generic.c:133:			usb_gadget_vbus_disconnect(otg->gadget);
> ./drivers/usb/phy/phy-fsl-usb.c:622:		usb_gadget_vbus_disconnect(otg->gadget);
> ./drivers/usb/phy/phy-msm-usb.c:786:		usb_gadget_vbus_disconnect(phy->otg->gadget);
> ./drivers/usb/phy/phy-mv-usb.c:236:		usb_gadget_vbus_disconnect(otg->gadget);
> ./drivers/usb/chipidea/otg.c:140:		usb_gadget_vbus_disconnect(&ci->gadget);
> ./drivers/usb/chipidea/otg_fsm.c:569:		usb_gadget_vbus_disconnect(&ci->gadget);
> b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_connect"
> ./drivers/power/isp1704_charger.c:272:				usb_gadget_connect(isp->phy->otg->gadget);
> ./drivers/usb/gadget/udc/fsl_udc_core.c:1215: * this func is used by usb_gadget_connect/disconnet
> ./drivers/usb/gadget/udc/udc-core.c:262:		usb_gadget_connect(udc->gadget);
> ./drivers/usb/gadget/udc/udc-core.c:671:		usb_gadget_connect(udc->gadget);
> ./drivers/usb/chipidea/udc.c:1593: * this func is used by usb_gadget_connect/disconnet
> b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_disconnect"
> ./drivers/power/isp1704_charger.c:302:			usb_gadget_disconnect(isp->phy->otg->gadget);
> ./drivers/power/isp1704_charger.c:504:		usb_gadget_disconnect(isp->phy->otg->gadget);
> ./drivers/usb/gadget/udc/udc-core.c:264:		usb_gadget_disconnect(udc->gadget);
> ./drivers/usb/gadget/udc/udc-core.c:502:	usb_gadget_disconnect(udc->gadget);
> ./drivers/usb/gadget/udc/udc-core.c:673:		usb_gadget_disconnect(udc->gadget);
> ./drivers/usb/gadget/composite.c:974: * Drivers must call usb_gadget_disconnect before calling this function
> ./drivers/usb/gadget/composite.c:2296: * the host, unless one of its components invokes usb_gadget_disconnect()
>
> Would you consider only keeps vbus and pull dp API at gadget.h, and move
> out others gadget APIs which is dedicated for gadget function?

no, sorry :-) All these drivers depend on the gadget API to work. For
host-only builds, they'll still work because of the stub implemented in
gadget.h.

Also, did you test the version I've apended to previous email? I noticed
that had one extra mistake which I correct in the version below:

8<------------------------------------------------------------------------

From bc79818198e67b1035107d8a3f76821d5d61c0b7 Mon Sep 17 00:00:00 2001
From: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Date: Tue, 31 May 2016 13:07:47 +0300
Subject: [PATCH] usb: gadget: move gadget API functions to udc-core

instead of defining all functions as static inlines,
let's move them to udc-core and export them with
EXPORT_SYMBOL_GPL, that way we can make sure that
only GPL drivers will use them.

As a side effect, it'll be nicer to add tracepoints
to the gadget API.

While at that, also fix Kconfig dependencies to
avoid randconfig build failures.

Signed-off-by: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/usb/gadget/udc/udc-core.c | 573 +++++++++++++++++++++++++++++++++++++
 drivers/usb/host/Kconfig          |   2 +-
 drivers/usb/phy/Kconfig           |   5 +-
 include/linux/usb/gadget.h        | 585 ++++----------------------------------
 4 files changed, 637 insertions(+), 528 deletions(-)

diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index 6e8300d6a737..d2f28bb6dbda 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -59,6 +59,579 @@ static int udc_bind_to_driver(struct usb_udc *udc,
 
 /* ------------------------------------------------------------------------- */
 
+/**
+ * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
+ * @ep:the endpoint being configured
+ * @maxpacket_limit:value of maximum packet size limit
+ *
+ * This function should be used only in UDC drivers to initialize endpoint
+ * (usually in probe function).
+ */
+void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
+					      unsigned maxpacket_limit)
+{
+	ep->maxpacket_limit = maxpacket_limit;
+	ep->maxpacket = maxpacket_limit;
+}
+EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
+
+/**
+ * usb_ep_enable - configure endpoint, making it usable
+ * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
+ *	drivers discover endpoints through the ep_list of a usb_gadget.
+ *
+ * When configurations are set, or when interface settings change, the driver
+ * will enable or disable the relevant endpoints.  while it is enabled, an
+ * endpoint may be used for i/o until the driver receives a disconnect() from
+ * the host or until the endpoint is disabled.
+ *
+ * the ep0 implementation (which calls this routine) must ensure that the
+ * hardware capabilities of each endpoint match the descriptor provided
+ * for it.  for example, an endpoint named "ep2in-bulk" would be usable
+ * for interrupt transfers as well as bulk, but it likely couldn't be used
+ * for iso transfers or for endpoint 14.  some endpoints are fully
+ * configurable, with more generic names like "ep-a".  (remember that for
+ * USB, "in" means "towards the USB master".)
+ *
+ * returns zero, or a negative error code.
+ */
+int usb_ep_enable(struct usb_ep *ep)
+{
+	int ret;
+
+	if (ep->enabled)
+		return 0;
+
+	ret = ep->ops->enable(ep, ep->desc);
+	if (ret)
+		return ret;
+
+	ep->enabled = true;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_ep_enable);
+
+/**
+ * usb_ep_disable - endpoint is no longer usable
+ * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
+ *
+ * no other task may be using this endpoint when this is called.
+ * any pending and uncompleted requests will complete with status
+ * indicating disconnect (-ESHUTDOWN) before this call returns.
+ * gadget drivers must call usb_ep_enable() again before queueing
+ * requests to the endpoint.
+ *
+ * returns zero, or a negative error code.
+ */
+int usb_ep_disable(struct usb_ep *ep)
+{
+	int ret;
+
+	if (!ep->enabled)
+		return 0;
+
+	ret = ep->ops->disable(ep);
+	if (ret)
+		return ret;
+
+	ep->enabled = false;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_ep_disable);
+
+/**
+ * usb_ep_alloc_request - allocate a request object to use with this endpoint
+ * @ep:the endpoint to be used with with the request
+ * @gfp_flags:GFP_* flags to use
+ *
+ * Request objects must be allocated with this call, since they normally
+ * need controller-specific setup and may even need endpoint-specific
+ * resources such as allocation of DMA descriptors.
+ * Requests may be submitted with usb_ep_queue(), and receive a single
+ * completion callback.  Free requests with usb_ep_free_request(), when
+ * they are no longer needed.
+ *
+ * Returns the request, or null if one could not be allocated.
+ */
+struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
+						       gfp_t gfp_flags)
+{
+	return ep->ops->alloc_request(ep, gfp_flags);
+}
+EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
+
+/**
+ * usb_ep_free_request - frees a request object
+ * @ep:the endpoint associated with the request
+ * @req:the request being freed
+ *
+ * Reverses the effect of usb_ep_alloc_request().
+ * Caller guarantees the request is not queued, and that it will
+ * no longer be requeued (or otherwise used).
+ */
+void usb_ep_free_request(struct usb_ep *ep,
+				       struct usb_request *req)
+{
+	ep->ops->free_request(ep, req);
+}
+EXPORT_SYMBOL_GPL(usb_ep_free_request);
+
+/**
+ * usb_ep_queue - queues (submits) an I/O request to an endpoint.
+ * @ep:the endpoint associated with the request
+ * @req:the request being submitted
+ * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
+ *	pre-allocate all necessary memory with the request.
+ *
+ * This tells the device controller to perform the specified request through
+ * that endpoint (reading or writing a buffer).  When the request completes,
+ * including being canceled by usb_ep_dequeue(), the request's completion
+ * routine is called to return the request to the driver.  Any endpoint
+ * (except control endpoints like ep0) may have more than one transfer
+ * request queued; they complete in FIFO order.  Once a gadget driver
+ * submits a request, that request may not be examined or modified until it
+ * is given back to that driver through the completion callback.
+ *
+ * Each request is turned into one or more packets.  The controller driver
+ * never merges adjacent requests into the same packet.  OUT transfers
+ * will sometimes use data that's already buffered in the hardware.
+ * Drivers can rely on the fact that the first byte of the request's buffer
+ * always corresponds to the first byte of some USB packet, for both
+ * IN and OUT transfers.
+ *
+ * Bulk endpoints can queue any amount of data; the transfer is packetized
+ * automatically.  The last packet will be short if the request doesn't fill it
+ * out completely.  Zero length packets (ZLPs) should be avoided in portable
+ * protocols since not all usb hardware can successfully handle zero length
+ * packets.  (ZLPs may be explicitly written, and may be implicitly written if
+ * the request 'zero' flag is set.)  Bulk endpoints may also be used
+ * for interrupt transfers; but the reverse is not true, and some endpoints
+ * won't support every interrupt transfer.  (Such as 768 byte packets.)
+ *
+ * Interrupt-only endpoints are less functional than bulk endpoints, for
+ * example by not supporting queueing or not handling buffers that are
+ * larger than the endpoint's maxpacket size.  They may also treat data
+ * toggle differently.
+ *
+ * Control endpoints ... after getting a setup() callback, the driver queues
+ * one response (even if it would be zero length).  That enables the
+ * status ack, after transferring data as specified in the response.  Setup
+ * functions may return negative error codes to generate protocol stalls.
+ * (Note that some USB device controllers disallow protocol stall responses
+ * in some cases.)  When control responses are deferred (the response is
+ * written after the setup callback returns), then usb_ep_set_halt() may be
+ * used on ep0 to trigger protocol stalls.  Depending on the controller,
+ * it may not be possible to trigger a status-stage protocol stall when the
+ * data stage is over, that is, from within the response's completion
+ * routine.
+ *
+ * For periodic endpoints, like interrupt or isochronous ones, the usb host
+ * arranges to poll once per interval, and the gadget driver usually will
+ * have queued some data to transfer at that time.
+ *
+ * Returns zero, or a negative error code.  Endpoints that are not enabled
+ * report errors; errors will also be
+ * reported when the usb peripheral is disconnected.
+ */
+int usb_ep_queue(struct usb_ep *ep,
+			       struct usb_request *req, gfp_t gfp_flags)
+{
+	if (WARN_ON_ONCE(!ep->enabled && ep->address))
+		return -ESHUTDOWN;
+
+	return ep->ops->queue(ep, req, gfp_flags);
+}
+EXPORT_SYMBOL_GPL(usb_ep_queue);
+
+/**
+ * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
+ * @ep:the endpoint associated with the request
+ * @req:the request being canceled
+ *
+ * If the request is still active on the endpoint, it is dequeued and its
+ * completion routine is called (with status -ECONNRESET); else a negative
+ * error code is returned. This is guaranteed to happen before the call to
+ * usb_ep_dequeue() returns.
+ *
+ * Note that some hardware can't clear out write fifos (to unlink the request
+ * at the head of the queue) except as part of disconnecting from usb. Such
+ * restrictions prevent drivers from supporting configuration changes,
+ * even to configuration zero (a "chapter 9" requirement).
+ */
+int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
+{
+	return ep->ops->dequeue(ep, req);
+}
+EXPORT_SYMBOL_GPL(usb_ep_dequeue);
+
+/**
+ * usb_ep_set_halt - sets the endpoint halt feature.
+ * @ep: the non-isochronous endpoint being stalled
+ *
+ * Use this to stall an endpoint, perhaps as an error report.
+ * Except for control endpoints,
+ * the endpoint stays halted (will not stream any data) until the host
+ * clears this feature; drivers may need to empty the endpoint's request
+ * queue first, to make sure no inappropriate transfers happen.
+ *
+ * Note that while an endpoint CLEAR_FEATURE will be invisible to the
+ * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
+ * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
+ * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
+ *
+ * Returns zero, or a negative error code.  On success, this call sets
+ * underlying hardware state that blocks data transfers.
+ * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
+ * transfer requests are still queued, or if the controller hardware
+ * (usually a FIFO) still holds bytes that the host hasn't collected.
+ */
+int usb_ep_set_halt(struct usb_ep *ep)
+{
+	return ep->ops->set_halt(ep, 1);
+}
+EXPORT_SYMBOL_GPL(usb_ep_set_halt);
+
+/**
+ * usb_ep_clear_halt - clears endpoint halt, and resets toggle
+ * @ep:the bulk or interrupt endpoint being reset
+ *
+ * Use this when responding to the standard usb "set interface" request,
+ * for endpoints that aren't reconfigured, after clearing any other state
+ * in the endpoint's i/o queue.
+ *
+ * Returns zero, or a negative error code.  On success, this call clears
+ * the underlying hardware state reflecting endpoint halt and data toggle.
+ * Note that some hardware can't support this request (like pxa2xx_udc),
+ * and accordingly can't correctly implement interface altsettings.
+ */
+int usb_ep_clear_halt(struct usb_ep *ep)
+{
+	return ep->ops->set_halt(ep, 0);
+}
+EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
+
+/**
+ * usb_ep_set_wedge - sets the halt feature and ignores clear requests
+ * @ep: the endpoint being wedged
+ *
+ * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
+ * requests. If the gadget driver clears the halt status, it will
+ * automatically unwedge the endpoint.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_ep_set_wedge(struct usb_ep *ep)
+{
+	if (ep->ops->set_wedge)
+		return ep->ops->set_wedge(ep);
+	else
+		return ep->ops->set_halt(ep, 1);
+}
+EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
+
+/**
+ * usb_ep_fifo_status - returns number of bytes in fifo, or error
+ * @ep: the endpoint whose fifo status is being checked.
+ *
+ * FIFO endpoints may have "unclaimed data" in them in certain cases,
+ * such as after aborted transfers.  Hosts may not have collected all
+ * the IN data written by the gadget driver (and reported by a request
+ * completion).  The gadget driver may not have collected all the data
+ * written OUT to it by the host.  Drivers that need precise handling for
+ * fault reporting or recovery may need to use this call.
+ *
+ * This returns the number of such bytes in the fifo, or a negative
+ * errno if the endpoint doesn't use a FIFO or doesn't support such
+ * precise handling.
+ */
+int usb_ep_fifo_status(struct usb_ep *ep)
+{
+	if (ep->ops->fifo_status)
+		return ep->ops->fifo_status(ep);
+	else
+		return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
+
+/**
+ * usb_ep_fifo_flush - flushes contents of a fifo
+ * @ep: the endpoint whose fifo is being flushed.
+ *
+ * This call may be used to flush the "unclaimed data" that may exist in
+ * an endpoint fifo after abnormal transaction terminations.  The call
+ * must never be used except when endpoint is not being used for any
+ * protocol translation.
+ */
+void usb_ep_fifo_flush(struct usb_ep *ep)
+{
+	if (ep->ops->fifo_flush)
+		ep->ops->fifo_flush(ep);
+}
+EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
+
+/* ------------------------------------------------------------------------- */
+
+/**
+ * usb_gadget_frame_number - returns the current frame number
+ * @gadget: controller that reports the frame number
+ *
+ * Returns the usb frame number, normally eleven bits from a SOF packet,
+ * or negative errno if this device doesn't support this capability.
+ */
+int usb_gadget_frame_number(struct usb_gadget *gadget)
+{
+	return gadget->ops->get_frame(gadget);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
+
+/**
+ * usb_gadget_wakeup - tries to wake up the host connected to this gadget
+ * @gadget: controller used to wake up the host
+ *
+ * Returns zero on success, else negative error code if the hardware
+ * doesn't support such attempts, or its support has not been enabled
+ * by the usb host.  Drivers must return device descriptors that report
+ * their ability to support this, or hosts won't enable it.
+ *
+ * This may also try to use SRP to wake the host and start enumeration,
+ * even if OTG isn't otherwise in use.  OTG devices may also start
+ * remote wakeup even when hosts don't explicitly enable it.
+ */
+int usb_gadget_wakeup(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->wakeup)
+		return -EOPNOTSUPP;
+	return gadget->ops->wakeup(gadget);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
+
+/**
+ * usb_gadget_set_selfpowered - sets the device selfpowered feature.
+ * @gadget:the device being declared as self-powered
+ *
+ * this affects the device status reported by the hardware driver
+ * to reflect that it now has a local power supply.
+ *
+ * returns zero on success, else negative errno.
+ */
+int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->set_selfpowered)
+		return -EOPNOTSUPP;
+	return gadget->ops->set_selfpowered(gadget, 1);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
+
+/**
+ * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
+ * @gadget:the device being declared as bus-powered
+ *
+ * this affects the device status reported by the hardware driver.
+ * some hardware may not support bus-powered operation, in which
+ * case this feature's value can never change.
+ *
+ * returns zero on success, else negative errno.
+ */
+int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->set_selfpowered)
+		return -EOPNOTSUPP;
+	return gadget->ops->set_selfpowered(gadget, 0);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
+
+/**
+ * usb_gadget_vbus_connect - Notify controller that VBUS is powered
+ * @gadget:The device which now has VBUS power.
+ * Context: can sleep
+ *
+ * This call is used by a driver for an external transceiver (or GPIO)
+ * that detects a VBUS power session starting.  Common responses include
+ * resuming the controller, activating the D+ (or D-) pullup to let the
+ * host detect that a USB device is attached, and starting to draw power
+ * (8mA or possibly more, especially after SET_CONFIGURATION).
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_vbus_connect(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->vbus_session)
+		return -EOPNOTSUPP;
+	return gadget->ops->vbus_session(gadget, 1);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
+
+/**
+ * usb_gadget_vbus_draw - constrain controller's VBUS power usage
+ * @gadget:The device whose VBUS usage is being described
+ * @mA:How much current to draw, in milliAmperes.  This should be twice
+ *	the value listed in the configuration descriptor bMaxPower field.
+ *
+ * This call is used by gadget drivers during SET_CONFIGURATION calls,
+ * reporting how much power the device may consume.  For example, this
+ * could affect how quickly batteries are recharged.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
+{
+	if (!gadget->ops->vbus_draw)
+		return -EOPNOTSUPP;
+	return gadget->ops->vbus_draw(gadget, mA);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
+
+/**
+ * usb_gadget_vbus_disconnect - notify controller about VBUS session end
+ * @gadget:the device whose VBUS supply is being described
+ * Context: can sleep
+ *
+ * This call is used by a driver for an external transceiver (or GPIO)
+ * that detects a VBUS power session ending.  Common responses include
+ * reversing everything done in usb_gadget_vbus_connect().
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
+{
+	if (!gadget->ops->vbus_session)
+		return -EOPNOTSUPP;
+	return gadget->ops->vbus_session(gadget, 0);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
+
+/**
+ * usb_gadget_connect - software-controlled connect to USB host
+ * @gadget:the peripheral being connected
+ *
+ * Enables the D+ (or potentially D-) pullup.  The host will start
+ * enumerating this gadget when the pullup is active and a VBUS session
+ * is active (the link is powered).  This pullup is always enabled unless
+ * usb_gadget_disconnect() has been used to disable it.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_connect(struct usb_gadget *gadget)
+{
+	int ret;
+
+	if (!gadget->ops->pullup)
+		return -EOPNOTSUPP;
+
+	if (gadget->deactivated) {
+		/*
+		 * If gadget is deactivated we only save new state.
+		 * Gadget will be connected automatically after activation.
+		 */
+		gadget->connected = true;
+		return 0;
+	}
+
+	ret = gadget->ops->pullup(gadget, 1);
+	if (!ret)
+		gadget->connected = 1;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_connect);
+
+/**
+ * usb_gadget_disconnect - software-controlled disconnect from USB host
+ * @gadget:the peripheral being disconnected
+ *
+ * Disables the D+ (or potentially D-) pullup, which the host may see
+ * as a disconnect (when a VBUS session is active).  Not all systems
+ * support software pullup controls.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_disconnect(struct usb_gadget *gadget)
+{
+	int ret;
+
+	if (!gadget->ops->pullup)
+		return -EOPNOTSUPP;
+
+	if (gadget->deactivated) {
+		/*
+		 * If gadget is deactivated we only save new state.
+		 * Gadget will stay disconnected after activation.
+		 */
+		gadget->connected = false;
+		return 0;
+	}
+
+	ret = gadget->ops->pullup(gadget, 0);
+	if (!ret)
+		gadget->connected = 0;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
+
+/**
+ * usb_gadget_deactivate - deactivate function which is not ready to work
+ * @gadget: the peripheral being deactivated
+ *
+ * This routine may be used during the gadget driver bind() call to prevent
+ * the peripheral from ever being visible to the USB host, unless later
+ * usb_gadget_activate() is called.  For example, user mode components may
+ * need to be activated before the system can talk to hosts.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_deactivate(struct usb_gadget *gadget)
+{
+	int ret;
+
+	if (gadget->deactivated)
+		return 0;
+
+	if (gadget->connected) {
+		ret = usb_gadget_disconnect(gadget);
+		if (ret)
+			return ret;
+		/*
+		 * If gadget was being connected before deactivation, we want
+		 * to reconnect it in usb_gadget_activate().
+		 */
+		gadget->connected = true;
+	}
+	gadget->deactivated = true;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
+
+/**
+ * usb_gadget_activate - activate function which is not ready to work
+ * @gadget: the peripheral being activated
+ *
+ * This routine activates gadget which was previously deactivated with
+ * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_activate(struct usb_gadget *gadget)
+{
+	if (!gadget->deactivated)
+		return 0;
+
+	gadget->deactivated = false;
+
+	/*
+	 * If gadget has been connected before deactivation, or became connected
+	 * while it was being deactivated, we call usb_gadget_connect().
+	 */
+	if (gadget->connected)
+		return usb_gadget_connect(gadget);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_activate);
+
+/* ------------------------------------------------------------------------- */
+
 #ifdef	CONFIG_HAS_DMA
 
 int usb_gadget_map_request_by_dev(struct device *dev,
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index d8f5674809e8..2e710a4cca52 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -180,7 +180,7 @@ config USB_EHCI_MXC
 config USB_EHCI_HCD_OMAP
 	tristate "EHCI support for OMAP3 and later chips"
 	depends on ARCH_OMAP
-	select NOP_USB_XCEIV
+	depends on NOP_USB_XCEIV
 	default y
 	---help---
 	  Enables support for the on-chip EHCI controller on
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index c6904742e2aa..ca509448b844 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -43,7 +43,7 @@ config ISP1301_OMAP
 config KEYSTONE_USB_PHY
 	tristate "Keystone USB PHY Driver"
 	depends on ARCH_KEYSTONE || COMPILE_TEST
-	select NOP_USB_XCEIV
+	depends on NOP_USB_XCEIV
 	help
 	  Enable this to support Keystone USB phy. This driver provides
 	  interface to interact with USB 2.0 and USB 3.0 PHY that is part
@@ -51,6 +51,7 @@ config KEYSTONE_USB_PHY
 
 config NOP_USB_XCEIV
 	tristate "NOP USB Transceiver Driver"
+	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, NOP can't be built-in
 	select USB_PHY
 	help
 	  This driver is to be used by all the usb transceiver which are either
@@ -63,9 +64,9 @@ config AM335X_CONTROL_USB
 config AM335X_PHY_USB
 	tristate "AM335x USB PHY Driver"
 	depends on ARM || COMPILE_TEST
+	depends on NOP_USB_XCEIV
 	select USB_PHY
 	select AM335X_CONTROL_USB
-	select NOP_USB_XCEIV
 	select USB_COMMON
 	help
 	  This driver provides PHY support for that phy which part for the
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 457651bf45b0..538ac836354b 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -228,307 +228,49 @@ struct usb_ep {
 
 /*-------------------------------------------------------------------------*/
 
-/**
- * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
- * @ep:the endpoint being configured
- * @maxpacket_limit:value of maximum packet size limit
- *
- * This function should be used only in UDC drivers to initialize endpoint
- * (usually in probe function).
- */
+#if IS_ENABLED(CONFIG_USB_GADGET)
+void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
+int usb_ep_enable(struct usb_ep *ep);
+int usb_ep_disable(struct usb_ep *ep);
+struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
+void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
+int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
+int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
+int usb_ep_set_halt(struct usb_ep *ep);
+int usb_ep_clear_halt(struct usb_ep *ep);
+int usb_ep_set_wedge(struct usb_ep *ep);
+int usb_ep_fifo_status(struct usb_ep *ep);
+void usb_ep_fifo_flush(struct usb_ep *ep);
+#else
 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
-					      unsigned maxpacket_limit)
-{
-	ep->maxpacket_limit = maxpacket_limit;
-	ep->maxpacket = maxpacket_limit;
-}
-
-/**
- * usb_ep_enable - configure endpoint, making it usable
- * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
- *	drivers discover endpoints through the ep_list of a usb_gadget.
- *
- * When configurations are set, or when interface settings change, the driver
- * will enable or disable the relevant endpoints.  while it is enabled, an
- * endpoint may be used for i/o until the driver receives a disconnect() from
- * the host or until the endpoint is disabled.
- *
- * the ep0 implementation (which calls this routine) must ensure that the
- * hardware capabilities of each endpoint match the descriptor provided
- * for it.  for example, an endpoint named "ep2in-bulk" would be usable
- * for interrupt transfers as well as bulk, but it likely couldn't be used
- * for iso transfers or for endpoint 14.  some endpoints are fully
- * configurable, with more generic names like "ep-a".  (remember that for
- * USB, "in" means "towards the USB master".)
- *
- * returns zero, or a negative error code.
- */
+		unsigned maxpacket_limit)
+{ }
 static inline int usb_ep_enable(struct usb_ep *ep)
-{
-	int ret;
-
-	if (ep->enabled)
-		return 0;
-
-	ret = ep->ops->enable(ep, ep->desc);
-	if (ret)
-		return ret;
-
-	ep->enabled = true;
-
-	return 0;
-}
-
-/**
- * usb_ep_disable - endpoint is no longer usable
- * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
- *
- * no other task may be using this endpoint when this is called.
- * any pending and uncompleted requests will complete with status
- * indicating disconnect (-ESHUTDOWN) before this call returns.
- * gadget drivers must call usb_ep_enable() again before queueing
- * requests to the endpoint.
- *
- * returns zero, or a negative error code.
- */
+{ return 0; }
 static inline int usb_ep_disable(struct usb_ep *ep)
-{
-	int ret;
-
-	if (!ep->enabled)
-		return 0;
-
-	ret = ep->ops->disable(ep);
-	if (ret)
-		return ret;
-
-	ep->enabled = false;
-
-	return 0;
-}
-
-/**
- * usb_ep_alloc_request - allocate a request object to use with this endpoint
- * @ep:the endpoint to be used with with the request
- * @gfp_flags:GFP_* flags to use
- *
- * Request objects must be allocated with this call, since they normally
- * need controller-specific setup and may even need endpoint-specific
- * resources such as allocation of DMA descriptors.
- * Requests may be submitted with usb_ep_queue(), and receive a single
- * completion callback.  Free requests with usb_ep_free_request(), when
- * they are no longer needed.
- *
- * Returns the request, or null if one could not be allocated.
- */
+{ return 0; }
 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
-						       gfp_t gfp_flags)
-{
-	return ep->ops->alloc_request(ep, gfp_flags);
-}
-
-/**
- * usb_ep_free_request - frees a request object
- * @ep:the endpoint associated with the request
- * @req:the request being freed
- *
- * Reverses the effect of usb_ep_alloc_request().
- * Caller guarantees the request is not queued, and that it will
- * no longer be requeued (or otherwise used).
- */
+		gfp_t gfp_flags)
+{ return NULL; }
 static inline void usb_ep_free_request(struct usb_ep *ep,
-				       struct usb_request *req)
-{
-	ep->ops->free_request(ep, req);
-}
-
-/**
- * usb_ep_queue - queues (submits) an I/O request to an endpoint.
- * @ep:the endpoint associated with the request
- * @req:the request being submitted
- * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
- *	pre-allocate all necessary memory with the request.
- *
- * This tells the device controller to perform the specified request through
- * that endpoint (reading or writing a buffer).  When the request completes,
- * including being canceled by usb_ep_dequeue(), the request's completion
- * routine is called to return the request to the driver.  Any endpoint
- * (except control endpoints like ep0) may have more than one transfer
- * request queued; they complete in FIFO order.  Once a gadget driver
- * submits a request, that request may not be examined or modified until it
- * is given back to that driver through the completion callback.
- *
- * Each request is turned into one or more packets.  The controller driver
- * never merges adjacent requests into the same packet.  OUT transfers
- * will sometimes use data that's already buffered in the hardware.
- * Drivers can rely on the fact that the first byte of the request's buffer
- * always corresponds to the first byte of some USB packet, for both
- * IN and OUT transfers.
- *
- * Bulk endpoints can queue any amount of data; the transfer is packetized
- * automatically.  The last packet will be short if the request doesn't fill it
- * out completely.  Zero length packets (ZLPs) should be avoided in portable
- * protocols since not all usb hardware can successfully handle zero length
- * packets.  (ZLPs may be explicitly written, and may be implicitly written if
- * the request 'zero' flag is set.)  Bulk endpoints may also be used
- * for interrupt transfers; but the reverse is not true, and some endpoints
- * won't support every interrupt transfer.  (Such as 768 byte packets.)
- *
- * Interrupt-only endpoints are less functional than bulk endpoints, for
- * example by not supporting queueing or not handling buffers that are
- * larger than the endpoint's maxpacket size.  They may also treat data
- * toggle differently.
- *
- * Control endpoints ... after getting a setup() callback, the driver queues
- * one response (even if it would be zero length).  That enables the
- * status ack, after transferring data as specified in the response.  Setup
- * functions may return negative error codes to generate protocol stalls.
- * (Note that some USB device controllers disallow protocol stall responses
- * in some cases.)  When control responses are deferred (the response is
- * written after the setup callback returns), then usb_ep_set_halt() may be
- * used on ep0 to trigger protocol stalls.  Depending on the controller,
- * it may not be possible to trigger a status-stage protocol stall when the
- * data stage is over, that is, from within the response's completion
- * routine.
- *
- * For periodic endpoints, like interrupt or isochronous ones, the usb host
- * arranges to poll once per interval, and the gadget driver usually will
- * have queued some data to transfer at that time.
- *
- * Returns zero, or a negative error code.  Endpoints that are not enabled
- * report errors; errors will also be
- * reported when the usb peripheral is disconnected.
- */
-static inline int usb_ep_queue(struct usb_ep *ep,
-			       struct usb_request *req, gfp_t gfp_flags)
-{
-	if (WARN_ON_ONCE(!ep->enabled && ep->address))
-		return -ESHUTDOWN;
-
-	return ep->ops->queue(ep, req, gfp_flags);
-}
-
-/**
- * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
- * @ep:the endpoint associated with the request
- * @req:the request being canceled
- *
- * If the request is still active on the endpoint, it is dequeued and its
- * completion routine is called (with status -ECONNRESET); else a negative
- * error code is returned. This is guaranteed to happen before the call to
- * usb_ep_dequeue() returns.
- *
- * Note that some hardware can't clear out write fifos (to unlink the request
- * at the head of the queue) except as part of disconnecting from usb. Such
- * restrictions prevent drivers from supporting configuration changes,
- * even to configuration zero (a "chapter 9" requirement).
- */
+		struct usb_request *req)
+{ }
+static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
+		gfp_t gfp_flags)
+{ return 0; }
 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
-{
-	return ep->ops->dequeue(ep, req);
-}
-
-/**
- * usb_ep_set_halt - sets the endpoint halt feature.
- * @ep: the non-isochronous endpoint being stalled
- *
- * Use this to stall an endpoint, perhaps as an error report.
- * Except for control endpoints,
- * the endpoint stays halted (will not stream any data) until the host
- * clears this feature; drivers may need to empty the endpoint's request
- * queue first, to make sure no inappropriate transfers happen.
- *
- * Note that while an endpoint CLEAR_FEATURE will be invisible to the
- * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
- * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
- * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
- *
- * Returns zero, or a negative error code.  On success, this call sets
- * underlying hardware state that blocks data transfers.
- * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
- * transfer requests are still queued, or if the controller hardware
- * (usually a FIFO) still holds bytes that the host hasn't collected.
- */
+{ return 0; }
 static inline int usb_ep_set_halt(struct usb_ep *ep)
-{
-	return ep->ops->set_halt(ep, 1);
-}
-
-/**
- * usb_ep_clear_halt - clears endpoint halt, and resets toggle
- * @ep:the bulk or interrupt endpoint being reset
- *
- * Use this when responding to the standard usb "set interface" request,
- * for endpoints that aren't reconfigured, after clearing any other state
- * in the endpoint's i/o queue.
- *
- * Returns zero, or a negative error code.  On success, this call clears
- * the underlying hardware state reflecting endpoint halt and data toggle.
- * Note that some hardware can't support this request (like pxa2xx_udc),
- * and accordingly can't correctly implement interface altsettings.
- */
+{ return 0; }
 static inline int usb_ep_clear_halt(struct usb_ep *ep)
-{
-	return ep->ops->set_halt(ep, 0);
-}
-
-/**
- * usb_ep_set_wedge - sets the halt feature and ignores clear requests
- * @ep: the endpoint being wedged
- *
- * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
- * requests. If the gadget driver clears the halt status, it will
- * automatically unwedge the endpoint.
- *
- * Returns zero on success, else negative errno.
- */
-static inline int
-usb_ep_set_wedge(struct usb_ep *ep)
-{
-	if (ep->ops->set_wedge)
-		return ep->ops->set_wedge(ep);
-	else
-		return ep->ops->set_halt(ep, 1);
-}
-
-/**
- * usb_ep_fifo_status - returns number of bytes in fifo, or error
- * @ep: the endpoint whose fifo status is being checked.
- *
- * FIFO endpoints may have "unclaimed data" in them in certain cases,
- * such as after aborted transfers.  Hosts may not have collected all
- * the IN data written by the gadget driver (and reported by a request
- * completion).  The gadget driver may not have collected all the data
- * written OUT to it by the host.  Drivers that need precise handling for
- * fault reporting or recovery may need to use this call.
- *
- * This returns the number of such bytes in the fifo, or a negative
- * errno if the endpoint doesn't use a FIFO or doesn't support such
- * precise handling.
- */
+{ return 0; }
+static inline int usb_ep_set_wedge(struct usb_ep *ep)
+{ return 0; }
 static inline int usb_ep_fifo_status(struct usb_ep *ep)
-{
-	if (ep->ops->fifo_status)
-		return ep->ops->fifo_status(ep);
-	else
-		return -EOPNOTSUPP;
-}
-
-/**
- * usb_ep_fifo_flush - flushes contents of a fifo
- * @ep: the endpoint whose fifo is being flushed.
- *
- * This call may be used to flush the "unclaimed data" that may exist in
- * an endpoint fifo after abnormal transaction terminations.  The call
- * must never be used except when endpoint is not being used for any
- * protocol translation.
- */
+{ return 0; }
 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
-{
-	if (ep->ops->fifo_flush)
-		ep->ops->fifo_flush(ep);
-}
-
+{ }
+#endif /* USB_GADGET */
 
 /*-------------------------------------------------------------------------*/
 
@@ -760,251 +502,44 @@ static inline int gadget_is_otg(struct usb_gadget *g)
 #endif
 }
 
-/**
- * usb_gadget_frame_number - returns the current frame number
- * @gadget: controller that reports the frame number
- *
- * Returns the usb frame number, normally eleven bits from a SOF packet,
- * or negative errno if this device doesn't support this capability.
- */
-static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
-{
-	return gadget->ops->get_frame(gadget);
-}
+/*-------------------------------------------------------------------------*/
 
-/**
- * usb_gadget_wakeup - tries to wake up the host connected to this gadget
- * @gadget: controller used to wake up the host
- *
- * Returns zero on success, else negative error code if the hardware
- * doesn't support such attempts, or its support has not been enabled
- * by the usb host.  Drivers must return device descriptors that report
- * their ability to support this, or hosts won't enable it.
- *
- * This may also try to use SRP to wake the host and start enumeration,
- * even if OTG isn't otherwise in use.  OTG devices may also start
- * remote wakeup even when hosts don't explicitly enable it.
- */
+#if IS_ENABLED(CONFIG_USB_GADGET)
+int usb_gadget_frame_number(struct usb_gadget *gadget);
+int usb_gadget_wakeup(struct usb_gadget *gadget);
+int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
+int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
+int usb_gadget_vbus_connect(struct usb_gadget *gadget);
+int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
+int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
+int usb_gadget_connect(struct usb_gadget *gadget);
+int usb_gadget_disconnect(struct usb_gadget *gadget);
+int usb_gadget_deactivate(struct usb_gadget *gadget);
+int usb_gadget_activate(struct usb_gadget *gadget);
+#else
+static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
+{ return 0; }
 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->wakeup)
-		return -EOPNOTSUPP;
-	return gadget->ops->wakeup(gadget);
-}
-
-/**
- * usb_gadget_set_selfpowered - sets the device selfpowered feature.
- * @gadget:the device being declared as self-powered
- *
- * this affects the device status reported by the hardware driver
- * to reflect that it now has a local power supply.
- *
- * returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->set_selfpowered)
-		return -EOPNOTSUPP;
-	return gadget->ops->set_selfpowered(gadget, 1);
-}
-
-/**
- * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
- * @gadget:the device being declared as bus-powered
- *
- * this affects the device status reported by the hardware driver.
- * some hardware may not support bus-powered operation, in which
- * case this feature's value can never change.
- *
- * returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->set_selfpowered)
-		return -EOPNOTSUPP;
-	return gadget->ops->set_selfpowered(gadget, 0);
-}
-
-/**
- * usb_gadget_vbus_connect - Notify controller that VBUS is powered
- * @gadget:The device which now has VBUS power.
- * Context: can sleep
- *
- * This call is used by a driver for an external transceiver (or GPIO)
- * that detects a VBUS power session starting.  Common responses include
- * resuming the controller, activating the D+ (or D-) pullup to let the
- * host detect that a USB device is attached, and starting to draw power
- * (8mA or possibly more, especially after SET_CONFIGURATION).
- *
- * Returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->vbus_session)
-		return -EOPNOTSUPP;
-	return gadget->ops->vbus_session(gadget, 1);
-}
-
-/**
- * usb_gadget_vbus_draw - constrain controller's VBUS power usage
- * @gadget:The device whose VBUS usage is being described
- * @mA:How much current to draw, in milliAmperes.  This should be twice
- *	the value listed in the configuration descriptor bMaxPower field.
- *
- * This call is used by gadget drivers during SET_CONFIGURATION calls,
- * reporting how much power the device may consume.  For example, this
- * could affect how quickly batteries are recharged.
- *
- * Returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
-{
-	if (!gadget->ops->vbus_draw)
-		return -EOPNOTSUPP;
-	return gadget->ops->vbus_draw(gadget, mA);
-}
-
-/**
- * usb_gadget_vbus_disconnect - notify controller about VBUS session end
- * @gadget:the device whose VBUS supply is being described
- * Context: can sleep
- *
- * This call is used by a driver for an external transceiver (or GPIO)
- * that detects a VBUS power session ending.  Common responses include
- * reversing everything done in usb_gadget_vbus_connect().
- *
- * Returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
-{
-	if (!gadget->ops->vbus_session)
-		return -EOPNOTSUPP;
-	return gadget->ops->vbus_session(gadget, 0);
-}
-
-/**
- * usb_gadget_connect - software-controlled connect to USB host
- * @gadget:the peripheral being connected
- *
- * Enables the D+ (or potentially D-) pullup.  The host will start
- * enumerating this gadget when the pullup is active and a VBUS session
- * is active (the link is powered).  This pullup is always enabled unless
- * usb_gadget_disconnect() has been used to disable it.
- *
- * Returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_connect(struct usb_gadget *gadget)
-{
-	int ret;
-
-	if (!gadget->ops->pullup)
-		return -EOPNOTSUPP;
-
-	if (gadget->deactivated) {
-		/*
-		 * If gadget is deactivated we only save new state.
-		 * Gadget will be connected automatically after activation.
-		 */
-		gadget->connected = true;
-		return 0;
-	}
-
-	ret = gadget->ops->pullup(gadget, 1);
-	if (!ret)
-		gadget->connected = 1;
-	return ret;
-}
-
-/**
- * usb_gadget_disconnect - software-controlled disconnect from USB host
- * @gadget:the peripheral being disconnected
- *
- * Disables the D+ (or potentially D-) pullup, which the host may see
- * as a disconnect (when a VBUS session is active).  Not all systems
- * support software pullup controls.
- *
- * Returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
-{
-	int ret;
-
-	if (!gadget->ops->pullup)
-		return -EOPNOTSUPP;
-
-	if (gadget->deactivated) {
-		/*
-		 * If gadget is deactivated we only save new state.
-		 * Gadget will stay disconnected after activation.
-		 */
-		gadget->connected = false;
-		return 0;
-	}
-
-	ret = gadget->ops->pullup(gadget, 0);
-	if (!ret)
-		gadget->connected = 0;
-	return ret;
-}
-
-/**
- * usb_gadget_deactivate - deactivate function which is not ready to work
- * @gadget: the peripheral being deactivated
- *
- * This routine may be used during the gadget driver bind() call to prevent
- * the peripheral from ever being visible to the USB host, unless later
- * usb_gadget_activate() is called.  For example, user mode components may
- * need to be activated before the system can talk to hosts.
- *
- * Returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
-{
-	int ret;
-
-	if (gadget->deactivated)
-		return 0;
-
-	if (gadget->connected) {
-		ret = usb_gadget_disconnect(gadget);
-		if (ret)
-			return ret;
-		/*
-		 * If gadget was being connected before deactivation, we want
-		 * to reconnect it in usb_gadget_activate().
-		 */
-		gadget->connected = true;
-	}
-	gadget->deactivated = true;
-
-	return 0;
-}
-
-/**
- * usb_gadget_activate - activate function which is not ready to work
- * @gadget: the peripheral being activated
- *
- * This routine activates gadget which was previously deactivated with
- * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
- *
- * Returns zero on success, else negative errno.
- */
+{ return 0; }
 static inline int usb_gadget_activate(struct usb_gadget *gadget)
-{
-	if (!gadget->deactivated)
-		return 0;
-
-	gadget->deactivated = false;
-
-	/*
-	 * If gadget has been connected before deactivation, or became connected
-	 * while it was being deactivated, we call usb_gadget_connect().
-	 */
-	if (gadget->connected)
-		return usb_gadget_connect(gadget);
-
-	return 0;
-}
+{ return 0; }
+#endif /* CONFIG_USB_GADGET */
 
 /*-------------------------------------------------------------------------*/
 
-- 
2.8.3



-- 
balbi

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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Peter Chen]

On Wed, Jun 08, 2016 at 12:50:57PM +0300, Felipe Balbi wrote:
> 
> Hi,
> 
> Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
> >> >> > Hi Felipe,
> >> >> >
> >> >> > It causes any drivers which use symbols from gadget.h needs to build
> >> >> > USB_GADGET even it only wants to be host function. Any significant
> >> >> > benefits after moving it to udc-core.c?
> >> >> 
> >> >> why is a host-only function calling into the gadget API?
> >> >> 
> >> >
> >> > Well, Just like this case, the chipidea driver can be configured host
> >> > mode only, but it still uses generic phy.
> >> 
> >> then we should allow for PHYs to not depend on the Gadget API, right?
> >
> > But you know it is not easy. The difficulty for gadget to do that is
> > vbus and pull dp, these two may be used by other subsystems, eg, vbus
> > may be used at PHY driver, dual-role switch driver, etc. The pull dp
> > may be used at USB charger driver, the secondary charger detection
> > needs to pull up dp for some charger designs.
> 
> that's fine. And if they really need that, they depend on the Gadget
> API. That _is_ something the gadget API defines afterall.
> 
> > See current kernel doc, it also says that.
> >
> > 	/**
> > 	 * usb_gadget_vbus_connect - Notify controller that VBUS is powered
> > 	 * @gadget:The device which now has VBUS power.
> > 	 * Context: can sleep
> > 	 *
> > 	 * This call is used by a driver for an external transceiver (or GPIO)
> > 	 * that detects a VBUS power session starting.  Common responses include
> > 	 * resuming the controller, activating the D+ (or D-) pullup to let the
> > 	 * host detect that a USB device is attached, and starting to draw power
> > 	 * (8mA or possibly more, especially after SET_CONFIGURATION).
> > 	 *
> > 	 * Returns zero on success, else negative errno.
> > 	 */
> > 	static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
> > 	{
> > 		if (!gadget->ops->vbus_session)
> > 			return -EOPNOTSUPP;
> > 		return gadget->ops->vbus_session(gadget, 1);
> > 	}
> >
> > See current situations:
> >
> > b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_vbus_connect"
> > ./drivers/phy/phy-twl4030-usb.c:559:		 * REVISIT usb_gadget_vbus_connect(...) as needed, ditto
> > ./drivers/usb/phy/phy-gpio-vbus-usb.c:126:		usb_gadget_vbus_connect(gpio_vbus->phy.otg->gadget);
> > ./drivers/usb/phy/phy-tahvo.c:89:				usb_gadget_vbus_connect(tu->phy.otg->gadget);
> > ./drivers/usb/phy/phy-isp1301-omap.c:929:	usb_gadget_vbus_connect(isp->phy.otg->gadget);
> > ./drivers/usb/phy/phy-isp1301-omap.c:1466:		usb_gadget_vbus_connect(otg->gadget);
> > ./drivers/usb/phy/phy-generic.c:122:			usb_gadget_vbus_connect(otg->gadget);
> > ./drivers/usb/phy/phy-generic.c:190:		usb_gadget_vbus_connect(gadget);
> > ./drivers/usb/phy/phy-msm-usb.c:783:		usb_gadget_vbus_connect(phy->otg->gadget);
> > ./drivers/usb/phy/phy-mv-usb.c:234:		usb_gadget_vbus_connect(otg->gadget);
> > ./drivers/usb/chipidea/otg.c:133:		usb_gadget_vbus_connect(&ci->gadget);
> > ./drivers/usb/chipidea/otg.c:138:		usb_gadget_vbus_connect(&ci->gadget);
> > ./drivers/usb/chipidea/udc.c:1964:		usb_gadget_vbus_connect(&ci->gadget);
> > ./drivers/usb/chipidea/otg_fsm.c:567:		usb_gadget_vbus_connect(&ci->gadget);
> > b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_vbus_disconnect"
> > ./drivers/usb/phy/phy-gpio-vbus-usb.c:145:		usb_gadget_vbus_disconnect(gpio_vbus->phy.otg->gadget);
> > ./drivers/usb/phy/phy-gpio-vbus-usb.c:200:		usb_gadget_vbus_disconnect(otg->gadget);
> > ./drivers/usb/phy/phy-tahvo.c:108:				usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
> > ./drivers/usb/phy/phy-tahvo.c:165:		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
> > ./drivers/usb/phy/phy-tahvo.c:175:		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
> > ./drivers/usb/phy/phy-isp1301-omap.c:312:	return usb_gadget_vbus_disconnect(isp->phy.otg->gadget);
> > ./drivers/usb/phy/phy-isp1301-omap.c:989:				usb_gadget_vbus_disconnect(otg->gadget);
> > ./drivers/usb/phy/phy-isp1301-omap.c:1342:		usb_gadget_vbus_disconnect(otg->gadget);
> > ./drivers/usb/phy/phy-generic.c:133:			usb_gadget_vbus_disconnect(otg->gadget);
> > ./drivers/usb/phy/phy-fsl-usb.c:622:		usb_gadget_vbus_disconnect(otg->gadget);
> > ./drivers/usb/phy/phy-msm-usb.c:786:		usb_gadget_vbus_disconnect(phy->otg->gadget);
> > ./drivers/usb/phy/phy-mv-usb.c:236:		usb_gadget_vbus_disconnect(otg->gadget);
> > ./drivers/usb/chipidea/otg.c:140:		usb_gadget_vbus_disconnect(&ci->gadget);
> > ./drivers/usb/chipidea/otg_fsm.c:569:		usb_gadget_vbus_disconnect(&ci->gadget);
> > b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_connect"
> > ./drivers/power/isp1704_charger.c:272:				usb_gadget_connect(isp->phy->otg->gadget);
> > ./drivers/usb/gadget/udc/fsl_udc_core.c:1215: * this func is used by usb_gadget_connect/disconnet
> > ./drivers/usb/gadget/udc/udc-core.c:262:		usb_gadget_connect(udc->gadget);
> > ./drivers/usb/gadget/udc/udc-core.c:671:		usb_gadget_connect(udc->gadget);
> > ./drivers/usb/chipidea/udc.c:1593: * this func is used by usb_gadget_connect/disconnet
> > b29397@linux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_disconnect"
> > ./drivers/power/isp1704_charger.c:302:			usb_gadget_disconnect(isp->phy->otg->gadget);
> > ./drivers/power/isp1704_charger.c:504:		usb_gadget_disconnect(isp->phy->otg->gadget);
> > ./drivers/usb/gadget/udc/udc-core.c:264:		usb_gadget_disconnect(udc->gadget);
> > ./drivers/usb/gadget/udc/udc-core.c:502:	usb_gadget_disconnect(udc->gadget);
> > ./drivers/usb/gadget/udc/udc-core.c:673:		usb_gadget_disconnect(udc->gadget);
> > ./drivers/usb/gadget/composite.c:974: * Drivers must call usb_gadget_disconnect before calling this function
> > ./drivers/usb/gadget/composite.c:2296: * the host, unless one of its components invokes usb_gadget_disconnect()
> >
> > Would you consider only keeps vbus and pull dp API at gadget.h, and move
> > out others gadget APIs which is dedicated for gadget function?
> 
> no, sorry :-) All these drivers depend on the gadget API to work. For
> host-only builds, they'll still work because of the stub implemented in
> gadget.h.

Do you want these drivers to add dependency on GADGET at Kconfig
or not? If you want, we don't need stub at gadget.h since the gadget
will be built if these driver is built. I assume you don't want, then
that's ok, we don't need to change anything on Kconfig to fix build
issue.

> 
> Also, did you test the version I've apended to previous email? I noticed
> that had one extra mistake which I correct in the version below:
> 

Sorry, I did not try since I still have some questions for solution:)

Peter

> 8<------------------------------------------------------------------------
> 
> From bc79818198e67b1035107d8a3f76821d5d61c0b7 Mon Sep 17 00:00:00 2001
> From: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Date: Tue, 31 May 2016 13:07:47 +0300
> Subject: [PATCH] usb: gadget: move gadget API functions to udc-core
> 
> instead of defining all functions as static inlines,
> let's move them to udc-core and export them with
> EXPORT_SYMBOL_GPL, that way we can make sure that
> only GPL drivers will use them.
> 
> As a side effect, it'll be nicer to add tracepoints
> to the gadget API.
> 
> While at that, also fix Kconfig dependencies to
> avoid randconfig build failures.
> 
> Signed-off-by: Felipe Balbi <felipe.balbi-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> ---
>  drivers/usb/gadget/udc/udc-core.c | 573 +++++++++++++++++++++++++++++++++++++
>  drivers/usb/host/Kconfig          |   2 +-
>  drivers/usb/phy/Kconfig           |   5 +-
>  include/linux/usb/gadget.h        | 585 ++++----------------------------------
>  4 files changed, 637 insertions(+), 528 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
> index 6e8300d6a737..d2f28bb6dbda 100644
> --- a/drivers/usb/gadget/udc/udc-core.c
> +++ b/drivers/usb/gadget/udc/udc-core.c
> @@ -59,6 +59,579 @@ static int udc_bind_to_driver(struct usb_udc *udc,
>  
>  /* ------------------------------------------------------------------------- */
>  
> +/**
> + * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
> + * @ep:the endpoint being configured
> + * @maxpacket_limit:value of maximum packet size limit
> + *
> + * This function should be used only in UDC drivers to initialize endpoint
> + * (usually in probe function).
> + */
> +void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
> +					      unsigned maxpacket_limit)
> +{
> +	ep->maxpacket_limit = maxpacket_limit;
> +	ep->maxpacket = maxpacket_limit;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit);
> +
> +/**
> + * usb_ep_enable - configure endpoint, making it usable
> + * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
> + *	drivers discover endpoints through the ep_list of a usb_gadget.
> + *
> + * When configurations are set, or when interface settings change, the driver
> + * will enable or disable the relevant endpoints.  while it is enabled, an
> + * endpoint may be used for i/o until the driver receives a disconnect() from
> + * the host or until the endpoint is disabled.
> + *
> + * the ep0 implementation (which calls this routine) must ensure that the
> + * hardware capabilities of each endpoint match the descriptor provided
> + * for it.  for example, an endpoint named "ep2in-bulk" would be usable
> + * for interrupt transfers as well as bulk, but it likely couldn't be used
> + * for iso transfers or for endpoint 14.  some endpoints are fully
> + * configurable, with more generic names like "ep-a".  (remember that for
> + * USB, "in" means "towards the USB master".)
> + *
> + * returns zero, or a negative error code.
> + */
> +int usb_ep_enable(struct usb_ep *ep)
> +{
> +	int ret;
> +
> +	if (ep->enabled)
> +		return 0;
> +
> +	ret = ep->ops->enable(ep, ep->desc);
> +	if (ret)
> +		return ret;
> +
> +	ep->enabled = true;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_enable);
> +
> +/**
> + * usb_ep_disable - endpoint is no longer usable
> + * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
> + *
> + * no other task may be using this endpoint when this is called.
> + * any pending and uncompleted requests will complete with status
> + * indicating disconnect (-ESHUTDOWN) before this call returns.
> + * gadget drivers must call usb_ep_enable() again before queueing
> + * requests to the endpoint.
> + *
> + * returns zero, or a negative error code.
> + */
> +int usb_ep_disable(struct usb_ep *ep)
> +{
> +	int ret;
> +
> +	if (!ep->enabled)
> +		return 0;
> +
> +	ret = ep->ops->disable(ep);
> +	if (ret)
> +		return ret;
> +
> +	ep->enabled = false;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_disable);
> +
> +/**
> + * usb_ep_alloc_request - allocate a request object to use with this endpoint
> + * @ep:the endpoint to be used with with the request
> + * @gfp_flags:GFP_* flags to use
> + *
> + * Request objects must be allocated with this call, since they normally
> + * need controller-specific setup and may even need endpoint-specific
> + * resources such as allocation of DMA descriptors.
> + * Requests may be submitted with usb_ep_queue(), and receive a single
> + * completion callback.  Free requests with usb_ep_free_request(), when
> + * they are no longer needed.
> + *
> + * Returns the request, or null if one could not be allocated.
> + */
> +struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
> +						       gfp_t gfp_flags)
> +{
> +	return ep->ops->alloc_request(ep, gfp_flags);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_alloc_request);
> +
> +/**
> + * usb_ep_free_request - frees a request object
> + * @ep:the endpoint associated with the request
> + * @req:the request being freed
> + *
> + * Reverses the effect of usb_ep_alloc_request().
> + * Caller guarantees the request is not queued, and that it will
> + * no longer be requeued (or otherwise used).
> + */
> +void usb_ep_free_request(struct usb_ep *ep,
> +				       struct usb_request *req)
> +{
> +	ep->ops->free_request(ep, req);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_free_request);
> +
> +/**
> + * usb_ep_queue - queues (submits) an I/O request to an endpoint.
> + * @ep:the endpoint associated with the request
> + * @req:the request being submitted
> + * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
> + *	pre-allocate all necessary memory with the request.
> + *
> + * This tells the device controller to perform the specified request through
> + * that endpoint (reading or writing a buffer).  When the request completes,
> + * including being canceled by usb_ep_dequeue(), the request's completion
> + * routine is called to return the request to the driver.  Any endpoint
> + * (except control endpoints like ep0) may have more than one transfer
> + * request queued; they complete in FIFO order.  Once a gadget driver
> + * submits a request, that request may not be examined or modified until it
> + * is given back to that driver through the completion callback.
> + *
> + * Each request is turned into one or more packets.  The controller driver
> + * never merges adjacent requests into the same packet.  OUT transfers
> + * will sometimes use data that's already buffered in the hardware.
> + * Drivers can rely on the fact that the first byte of the request's buffer
> + * always corresponds to the first byte of some USB packet, for both
> + * IN and OUT transfers.
> + *
> + * Bulk endpoints can queue any amount of data; the transfer is packetized
> + * automatically.  The last packet will be short if the request doesn't fill it
> + * out completely.  Zero length packets (ZLPs) should be avoided in portable
> + * protocols since not all usb hardware can successfully handle zero length
> + * packets.  (ZLPs may be explicitly written, and may be implicitly written if
> + * the request 'zero' flag is set.)  Bulk endpoints may also be used
> + * for interrupt transfers; but the reverse is not true, and some endpoints
> + * won't support every interrupt transfer.  (Such as 768 byte packets.)
> + *
> + * Interrupt-only endpoints are less functional than bulk endpoints, for
> + * example by not supporting queueing or not handling buffers that are
> + * larger than the endpoint's maxpacket size.  They may also treat data
> + * toggle differently.
> + *
> + * Control endpoints ... after getting a setup() callback, the driver queues
> + * one response (even if it would be zero length).  That enables the
> + * status ack, after transferring data as specified in the response.  Setup
> + * functions may return negative error codes to generate protocol stalls.
> + * (Note that some USB device controllers disallow protocol stall responses
> + * in some cases.)  When control responses are deferred (the response is
> + * written after the setup callback returns), then usb_ep_set_halt() may be
> + * used on ep0 to trigger protocol stalls.  Depending on the controller,
> + * it may not be possible to trigger a status-stage protocol stall when the
> + * data stage is over, that is, from within the response's completion
> + * routine.
> + *
> + * For periodic endpoints, like interrupt or isochronous ones, the usb host
> + * arranges to poll once per interval, and the gadget driver usually will
> + * have queued some data to transfer at that time.
> + *
> + * Returns zero, or a negative error code.  Endpoints that are not enabled
> + * report errors; errors will also be
> + * reported when the usb peripheral is disconnected.
> + */
> +int usb_ep_queue(struct usb_ep *ep,
> +			       struct usb_request *req, gfp_t gfp_flags)
> +{
> +	if (WARN_ON_ONCE(!ep->enabled && ep->address))
> +		return -ESHUTDOWN;
> +
> +	return ep->ops->queue(ep, req, gfp_flags);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_queue);
> +
> +/**
> + * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
> + * @ep:the endpoint associated with the request
> + * @req:the request being canceled
> + *
> + * If the request is still active on the endpoint, it is dequeued and its
> + * completion routine is called (with status -ECONNRESET); else a negative
> + * error code is returned. This is guaranteed to happen before the call to
> + * usb_ep_dequeue() returns.
> + *
> + * Note that some hardware can't clear out write fifos (to unlink the request
> + * at the head of the queue) except as part of disconnecting from usb. Such
> + * restrictions prevent drivers from supporting configuration changes,
> + * even to configuration zero (a "chapter 9" requirement).
> + */
> +int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
> +{
> +	return ep->ops->dequeue(ep, req);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_dequeue);
> +
> +/**
> + * usb_ep_set_halt - sets the endpoint halt feature.
> + * @ep: the non-isochronous endpoint being stalled
> + *
> + * Use this to stall an endpoint, perhaps as an error report.
> + * Except for control endpoints,
> + * the endpoint stays halted (will not stream any data) until the host
> + * clears this feature; drivers may need to empty the endpoint's request
> + * queue first, to make sure no inappropriate transfers happen.
> + *
> + * Note that while an endpoint CLEAR_FEATURE will be invisible to the
> + * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
> + * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
> + * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
> + *
> + * Returns zero, or a negative error code.  On success, this call sets
> + * underlying hardware state that blocks data transfers.
> + * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
> + * transfer requests are still queued, or if the controller hardware
> + * (usually a FIFO) still holds bytes that the host hasn't collected.
> + */
> +int usb_ep_set_halt(struct usb_ep *ep)
> +{
> +	return ep->ops->set_halt(ep, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_halt);
> +
> +/**
> + * usb_ep_clear_halt - clears endpoint halt, and resets toggle
> + * @ep:the bulk or interrupt endpoint being reset
> + *
> + * Use this when responding to the standard usb "set interface" request,
> + * for endpoints that aren't reconfigured, after clearing any other state
> + * in the endpoint's i/o queue.
> + *
> + * Returns zero, or a negative error code.  On success, this call clears
> + * the underlying hardware state reflecting endpoint halt and data toggle.
> + * Note that some hardware can't support this request (like pxa2xx_udc),
> + * and accordingly can't correctly implement interface altsettings.
> + */
> +int usb_ep_clear_halt(struct usb_ep *ep)
> +{
> +	return ep->ops->set_halt(ep, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_clear_halt);
> +
> +/**
> + * usb_ep_set_wedge - sets the halt feature and ignores clear requests
> + * @ep: the endpoint being wedged
> + *
> + * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
> + * requests. If the gadget driver clears the halt status, it will
> + * automatically unwedge the endpoint.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_ep_set_wedge(struct usb_ep *ep)
> +{
> +	if (ep->ops->set_wedge)
> +		return ep->ops->set_wedge(ep);
> +	else
> +		return ep->ops->set_halt(ep, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_set_wedge);
> +
> +/**
> + * usb_ep_fifo_status - returns number of bytes in fifo, or error
> + * @ep: the endpoint whose fifo status is being checked.
> + *
> + * FIFO endpoints may have "unclaimed data" in them in certain cases,
> + * such as after aborted transfers.  Hosts may not have collected all
> + * the IN data written by the gadget driver (and reported by a request
> + * completion).  The gadget driver may not have collected all the data
> + * written OUT to it by the host.  Drivers that need precise handling for
> + * fault reporting or recovery may need to use this call.
> + *
> + * This returns the number of such bytes in the fifo, or a negative
> + * errno if the endpoint doesn't use a FIFO or doesn't support such
> + * precise handling.
> + */
> +int usb_ep_fifo_status(struct usb_ep *ep)
> +{
> +	if (ep->ops->fifo_status)
> +		return ep->ops->fifo_status(ep);
> +	else
> +		return -EOPNOTSUPP;
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_fifo_status);
> +
> +/**
> + * usb_ep_fifo_flush - flushes contents of a fifo
> + * @ep: the endpoint whose fifo is being flushed.
> + *
> + * This call may be used to flush the "unclaimed data" that may exist in
> + * an endpoint fifo after abnormal transaction terminations.  The call
> + * must never be used except when endpoint is not being used for any
> + * protocol translation.
> + */
> +void usb_ep_fifo_flush(struct usb_ep *ep)
> +{
> +	if (ep->ops->fifo_flush)
> +		ep->ops->fifo_flush(ep);
> +}
> +EXPORT_SYMBOL_GPL(usb_ep_fifo_flush);
> +
> +/* ------------------------------------------------------------------------- */
> +
> +/**
> + * usb_gadget_frame_number - returns the current frame number
> + * @gadget: controller that reports the frame number
> + *
> + * Returns the usb frame number, normally eleven bits from a SOF packet,
> + * or negative errno if this device doesn't support this capability.
> + */
> +int usb_gadget_frame_number(struct usb_gadget *gadget)
> +{
> +	return gadget->ops->get_frame(gadget);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_frame_number);
> +
> +/**
> + * usb_gadget_wakeup - tries to wake up the host connected to this gadget
> + * @gadget: controller used to wake up the host
> + *
> + * Returns zero on success, else negative error code if the hardware
> + * doesn't support such attempts, or its support has not been enabled
> + * by the usb host.  Drivers must return device descriptors that report
> + * their ability to support this, or hosts won't enable it.
> + *
> + * This may also try to use SRP to wake the host and start enumeration,
> + * even if OTG isn't otherwise in use.  OTG devices may also start
> + * remote wakeup even when hosts don't explicitly enable it.
> + */
> +int usb_gadget_wakeup(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->wakeup)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->wakeup(gadget);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
> +
> +/**
> + * usb_gadget_set_selfpowered - sets the device selfpowered feature.
> + * @gadget:the device being declared as self-powered
> + *
> + * this affects the device status reported by the hardware driver
> + * to reflect that it now has a local power supply.
> + *
> + * returns zero on success, else negative errno.
> + */
> +int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->set_selfpowered)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->set_selfpowered(gadget, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_set_selfpowered);
> +
> +/**
> + * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
> + * @gadget:the device being declared as bus-powered
> + *
> + * this affects the device status reported by the hardware driver.
> + * some hardware may not support bus-powered operation, in which
> + * case this feature's value can never change.
> + *
> + * returns zero on success, else negative errno.
> + */
> +int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->set_selfpowered)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->set_selfpowered(gadget, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_clear_selfpowered);
> +
> +/**
> + * usb_gadget_vbus_connect - Notify controller that VBUS is powered
> + * @gadget:The device which now has VBUS power.
> + * Context: can sleep
> + *
> + * This call is used by a driver for an external transceiver (or GPIO)
> + * that detects a VBUS power session starting.  Common responses include
> + * resuming the controller, activating the D+ (or D-) pullup to let the
> + * host detect that a USB device is attached, and starting to draw power
> + * (8mA or possibly more, especially after SET_CONFIGURATION).
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_connect(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->vbus_session)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_session(gadget, 1);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_connect);
> +
> +/**
> + * usb_gadget_vbus_draw - constrain controller's VBUS power usage
> + * @gadget:The device whose VBUS usage is being described
> + * @mA:How much current to draw, in milliAmperes.  This should be twice
> + *	the value listed in the configuration descriptor bMaxPower field.
> + *
> + * This call is used by gadget drivers during SET_CONFIGURATION calls,
> + * reporting how much power the device may consume.  For example, this
> + * could affect how quickly batteries are recharged.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
> +{
> +	if (!gadget->ops->vbus_draw)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_draw(gadget, mA);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_draw);
> +
> +/**
> + * usb_gadget_vbus_disconnect - notify controller about VBUS session end
> + * @gadget:the device whose VBUS supply is being described
> + * Context: can sleep
> + *
> + * This call is used by a driver for an external transceiver (or GPIO)
> + * that detects a VBUS power session ending.  Common responses include
> + * reversing everything done in usb_gadget_vbus_connect().
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
> +{
> +	if (!gadget->ops->vbus_session)
> +		return -EOPNOTSUPP;
> +	return gadget->ops->vbus_session(gadget, 0);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
> +
> +/**
> + * usb_gadget_connect - software-controlled connect to USB host
> + * @gadget:the peripheral being connected
> + *
> + * Enables the D+ (or potentially D-) pullup.  The host will start
> + * enumerating this gadget when the pullup is active and a VBUS session
> + * is active (the link is powered).  This pullup is always enabled unless
> + * usb_gadget_disconnect() has been used to disable it.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_connect(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (!gadget->ops->pullup)
> +		return -EOPNOTSUPP;
> +
> +	if (gadget->deactivated) {
> +		/*
> +		 * If gadget is deactivated we only save new state.
> +		 * Gadget will be connected automatically after activation.
> +		 */
> +		gadget->connected = true;
> +		return 0;
> +	}
> +
> +	ret = gadget->ops->pullup(gadget, 1);
> +	if (!ret)
> +		gadget->connected = 1;
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_connect);
> +
> +/**
> + * usb_gadget_disconnect - software-controlled disconnect from USB host
> + * @gadget:the peripheral being disconnected
> + *
> + * Disables the D+ (or potentially D-) pullup, which the host may see
> + * as a disconnect (when a VBUS session is active).  Not all systems
> + * support software pullup controls.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_disconnect(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (!gadget->ops->pullup)
> +		return -EOPNOTSUPP;
> +
> +	if (gadget->deactivated) {
> +		/*
> +		 * If gadget is deactivated we only save new state.
> +		 * Gadget will stay disconnected after activation.
> +		 */
> +		gadget->connected = false;
> +		return 0;
> +	}
> +
> +	ret = gadget->ops->pullup(gadget, 0);
> +	if (!ret)
> +		gadget->connected = 0;
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
> +
> +/**
> + * usb_gadget_deactivate - deactivate function which is not ready to work
> + * @gadget: the peripheral being deactivated
> + *
> + * This routine may be used during the gadget driver bind() call to prevent
> + * the peripheral from ever being visible to the USB host, unless later
> + * usb_gadget_activate() is called.  For example, user mode components may
> + * need to be activated before the system can talk to hosts.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_deactivate(struct usb_gadget *gadget)
> +{
> +	int ret;
> +
> +	if (gadget->deactivated)
> +		return 0;
> +
> +	if (gadget->connected) {
> +		ret = usb_gadget_disconnect(gadget);
> +		if (ret)
> +			return ret;
> +		/*
> +		 * If gadget was being connected before deactivation, we want
> +		 * to reconnect it in usb_gadget_activate().
> +		 */
> +		gadget->connected = true;
> +	}
> +	gadget->deactivated = true;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
> +
> +/**
> + * usb_gadget_activate - activate function which is not ready to work
> + * @gadget: the peripheral being activated
> + *
> + * This routine activates gadget which was previously deactivated with
> + * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
> + *
> + * Returns zero on success, else negative errno.
> + */
> +int usb_gadget_activate(struct usb_gadget *gadget)
> +{
> +	if (!gadget->deactivated)
> +		return 0;
> +
> +	gadget->deactivated = false;
> +
> +	/*
> +	 * If gadget has been connected before deactivation, or became connected
> +	 * while it was being deactivated, we call usb_gadget_connect().
> +	 */
> +	if (gadget->connected)
> +		return usb_gadget_connect(gadget);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_activate);
> +
> +/* ------------------------------------------------------------------------- */
> +
>  #ifdef	CONFIG_HAS_DMA
>  
>  int usb_gadget_map_request_by_dev(struct device *dev,
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index d8f5674809e8..2e710a4cca52 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -180,7 +180,7 @@ config USB_EHCI_MXC
>  config USB_EHCI_HCD_OMAP
>  	tristate "EHCI support for OMAP3 and later chips"
>  	depends on ARCH_OMAP
> -	select NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	default y
>  	---help---
>  	  Enables support for the on-chip EHCI controller on
> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
> index c6904742e2aa..ca509448b844 100644
> --- a/drivers/usb/phy/Kconfig
> +++ b/drivers/usb/phy/Kconfig
> @@ -43,7 +43,7 @@ config ISP1301_OMAP
>  config KEYSTONE_USB_PHY
>  	tristate "Keystone USB PHY Driver"
>  	depends on ARCH_KEYSTONE || COMPILE_TEST
> -	select NOP_USB_XCEIV
> +	depends on NOP_USB_XCEIV
>  	help
>  	  Enable this to support Keystone USB phy. This driver provides
>  	  interface to interact with USB 2.0 and USB 3.0 PHY that is part
> @@ -51,6 +51,7 @@ config KEYSTONE_USB_PHY
>  
>  config NOP_USB_XCEIV
>  	tristate "NOP USB Transceiver Driver"
> +	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, NOP can't be built-in
>  	select USB_PHY
>  	help
>  	  This driver is to be used by all the usb transceiver which are either
> @@ -63,9 +64,9 @@ config AM335X_CONTROL_USB
>  config AM335X_PHY_USB
>  	tristate "AM335x USB PHY Driver"
>  	depends on ARM || COMPILE_TEST
> +	depends on NOP_USB_XCEIV
>  	select USB_PHY
>  	select AM335X_CONTROL_USB
> -	select NOP_USB_XCEIV
>  	select USB_COMMON
>  	help
>  	  This driver provides PHY support for that phy which part for the
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 457651bf45b0..538ac836354b 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -228,307 +228,49 @@ struct usb_ep {
>  
>  /*-------------------------------------------------------------------------*/
>  
> -/**
> - * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
> - * @ep:the endpoint being configured
> - * @maxpacket_limit:value of maximum packet size limit
> - *
> - * This function should be used only in UDC drivers to initialize endpoint
> - * (usually in probe function).
> - */
> +#if IS_ENABLED(CONFIG_USB_GADGET)
> +void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
> +int usb_ep_enable(struct usb_ep *ep);
> +int usb_ep_disable(struct usb_ep *ep);
> +struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
> +void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
> +int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
> +int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
> +int usb_ep_set_halt(struct usb_ep *ep);
> +int usb_ep_clear_halt(struct usb_ep *ep);
> +int usb_ep_set_wedge(struct usb_ep *ep);
> +int usb_ep_fifo_status(struct usb_ep *ep);
> +void usb_ep_fifo_flush(struct usb_ep *ep);
> +#else
>  static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
> -					      unsigned maxpacket_limit)
> -{
> -	ep->maxpacket_limit = maxpacket_limit;
> -	ep->maxpacket = maxpacket_limit;
> -}
> -
> -/**
> - * usb_ep_enable - configure endpoint, making it usable
> - * @ep:the endpoint being configured.  may not be the endpoint named "ep0".
> - *	drivers discover endpoints through the ep_list of a usb_gadget.
> - *
> - * When configurations are set, or when interface settings change, the driver
> - * will enable or disable the relevant endpoints.  while it is enabled, an
> - * endpoint may be used for i/o until the driver receives a disconnect() from
> - * the host or until the endpoint is disabled.
> - *
> - * the ep0 implementation (which calls this routine) must ensure that the
> - * hardware capabilities of each endpoint match the descriptor provided
> - * for it.  for example, an endpoint named "ep2in-bulk" would be usable
> - * for interrupt transfers as well as bulk, but it likely couldn't be used
> - * for iso transfers or for endpoint 14.  some endpoints are fully
> - * configurable, with more generic names like "ep-a".  (remember that for
> - * USB, "in" means "towards the USB master".)
> - *
> - * returns zero, or a negative error code.
> - */
> +		unsigned maxpacket_limit)
> +{ }
>  static inline int usb_ep_enable(struct usb_ep *ep)
> -{
> -	int ret;
> -
> -	if (ep->enabled)
> -		return 0;
> -
> -	ret = ep->ops->enable(ep, ep->desc);
> -	if (ret)
> -		return ret;
> -
> -	ep->enabled = true;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_ep_disable - endpoint is no longer usable
> - * @ep:the endpoint being unconfigured.  may not be the endpoint named "ep0".
> - *
> - * no other task may be using this endpoint when this is called.
> - * any pending and uncompleted requests will complete with status
> - * indicating disconnect (-ESHUTDOWN) before this call returns.
> - * gadget drivers must call usb_ep_enable() again before queueing
> - * requests to the endpoint.
> - *
> - * returns zero, or a negative error code.
> - */
> +{ return 0; }
>  static inline int usb_ep_disable(struct usb_ep *ep)
> -{
> -	int ret;
> -
> -	if (!ep->enabled)
> -		return 0;
> -
> -	ret = ep->ops->disable(ep);
> -	if (ret)
> -		return ret;
> -
> -	ep->enabled = false;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_ep_alloc_request - allocate a request object to use with this endpoint
> - * @ep:the endpoint to be used with with the request
> - * @gfp_flags:GFP_* flags to use
> - *
> - * Request objects must be allocated with this call, since they normally
> - * need controller-specific setup and may even need endpoint-specific
> - * resources such as allocation of DMA descriptors.
> - * Requests may be submitted with usb_ep_queue(), and receive a single
> - * completion callback.  Free requests with usb_ep_free_request(), when
> - * they are no longer needed.
> - *
> - * Returns the request, or null if one could not be allocated.
> - */
> +{ return 0; }
>  static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
> -						       gfp_t gfp_flags)
> -{
> -	return ep->ops->alloc_request(ep, gfp_flags);
> -}
> -
> -/**
> - * usb_ep_free_request - frees a request object
> - * @ep:the endpoint associated with the request
> - * @req:the request being freed
> - *
> - * Reverses the effect of usb_ep_alloc_request().
> - * Caller guarantees the request is not queued, and that it will
> - * no longer be requeued (or otherwise used).
> - */
> +		gfp_t gfp_flags)
> +{ return NULL; }
>  static inline void usb_ep_free_request(struct usb_ep *ep,
> -				       struct usb_request *req)
> -{
> -	ep->ops->free_request(ep, req);
> -}
> -
> -/**
> - * usb_ep_queue - queues (submits) an I/O request to an endpoint.
> - * @ep:the endpoint associated with the request
> - * @req:the request being submitted
> - * @gfp_flags: GFP_* flags to use in case the lower level driver couldn't
> - *	pre-allocate all necessary memory with the request.
> - *
> - * This tells the device controller to perform the specified request through
> - * that endpoint (reading or writing a buffer).  When the request completes,
> - * including being canceled by usb_ep_dequeue(), the request's completion
> - * routine is called to return the request to the driver.  Any endpoint
> - * (except control endpoints like ep0) may have more than one transfer
> - * request queued; they complete in FIFO order.  Once a gadget driver
> - * submits a request, that request may not be examined or modified until it
> - * is given back to that driver through the completion callback.
> - *
> - * Each request is turned into one or more packets.  The controller driver
> - * never merges adjacent requests into the same packet.  OUT transfers
> - * will sometimes use data that's already buffered in the hardware.
> - * Drivers can rely on the fact that the first byte of the request's buffer
> - * always corresponds to the first byte of some USB packet, for both
> - * IN and OUT transfers.
> - *
> - * Bulk endpoints can queue any amount of data; the transfer is packetized
> - * automatically.  The last packet will be short if the request doesn't fill it
> - * out completely.  Zero length packets (ZLPs) should be avoided in portable
> - * protocols since not all usb hardware can successfully handle zero length
> - * packets.  (ZLPs may be explicitly written, and may be implicitly written if
> - * the request 'zero' flag is set.)  Bulk endpoints may also be used
> - * for interrupt transfers; but the reverse is not true, and some endpoints
> - * won't support every interrupt transfer.  (Such as 768 byte packets.)
> - *
> - * Interrupt-only endpoints are less functional than bulk endpoints, for
> - * example by not supporting queueing or not handling buffers that are
> - * larger than the endpoint's maxpacket size.  They may also treat data
> - * toggle differently.
> - *
> - * Control endpoints ... after getting a setup() callback, the driver queues
> - * one response (even if it would be zero length).  That enables the
> - * status ack, after transferring data as specified in the response.  Setup
> - * functions may return negative error codes to generate protocol stalls.
> - * (Note that some USB device controllers disallow protocol stall responses
> - * in some cases.)  When control responses are deferred (the response is
> - * written after the setup callback returns), then usb_ep_set_halt() may be
> - * used on ep0 to trigger protocol stalls.  Depending on the controller,
> - * it may not be possible to trigger a status-stage protocol stall when the
> - * data stage is over, that is, from within the response's completion
> - * routine.
> - *
> - * For periodic endpoints, like interrupt or isochronous ones, the usb host
> - * arranges to poll once per interval, and the gadget driver usually will
> - * have queued some data to transfer at that time.
> - *
> - * Returns zero, or a negative error code.  Endpoints that are not enabled
> - * report errors; errors will also be
> - * reported when the usb peripheral is disconnected.
> - */
> -static inline int usb_ep_queue(struct usb_ep *ep,
> -			       struct usb_request *req, gfp_t gfp_flags)
> -{
> -	if (WARN_ON_ONCE(!ep->enabled && ep->address))
> -		return -ESHUTDOWN;
> -
> -	return ep->ops->queue(ep, req, gfp_flags);
> -}
> -
> -/**
> - * usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an endpoint
> - * @ep:the endpoint associated with the request
> - * @req:the request being canceled
> - *
> - * If the request is still active on the endpoint, it is dequeued and its
> - * completion routine is called (with status -ECONNRESET); else a negative
> - * error code is returned. This is guaranteed to happen before the call to
> - * usb_ep_dequeue() returns.
> - *
> - * Note that some hardware can't clear out write fifos (to unlink the request
> - * at the head of the queue) except as part of disconnecting from usb. Such
> - * restrictions prevent drivers from supporting configuration changes,
> - * even to configuration zero (a "chapter 9" requirement).
> - */
> +		struct usb_request *req)
> +{ }
> +static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
> +		gfp_t gfp_flags)
> +{ return 0; }
>  static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
> -{
> -	return ep->ops->dequeue(ep, req);
> -}
> -
> -/**
> - * usb_ep_set_halt - sets the endpoint halt feature.
> - * @ep: the non-isochronous endpoint being stalled
> - *
> - * Use this to stall an endpoint, perhaps as an error report.
> - * Except for control endpoints,
> - * the endpoint stays halted (will not stream any data) until the host
> - * clears this feature; drivers may need to empty the endpoint's request
> - * queue first, to make sure no inappropriate transfers happen.
> - *
> - * Note that while an endpoint CLEAR_FEATURE will be invisible to the
> - * gadget driver, a SET_INTERFACE will not be.  To reset endpoints for the
> - * current altsetting, see usb_ep_clear_halt().  When switching altsettings,
> - * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints.
> - *
> - * Returns zero, or a negative error code.  On success, this call sets
> - * underlying hardware state that blocks data transfers.
> - * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any
> - * transfer requests are still queued, or if the controller hardware
> - * (usually a FIFO) still holds bytes that the host hasn't collected.
> - */
> +{ return 0; }
>  static inline int usb_ep_set_halt(struct usb_ep *ep)
> -{
> -	return ep->ops->set_halt(ep, 1);
> -}
> -
> -/**
> - * usb_ep_clear_halt - clears endpoint halt, and resets toggle
> - * @ep:the bulk or interrupt endpoint being reset
> - *
> - * Use this when responding to the standard usb "set interface" request,
> - * for endpoints that aren't reconfigured, after clearing any other state
> - * in the endpoint's i/o queue.
> - *
> - * Returns zero, or a negative error code.  On success, this call clears
> - * the underlying hardware state reflecting endpoint halt and data toggle.
> - * Note that some hardware can't support this request (like pxa2xx_udc),
> - * and accordingly can't correctly implement interface altsettings.
> - */
> +{ return 0; }
>  static inline int usb_ep_clear_halt(struct usb_ep *ep)
> -{
> -	return ep->ops->set_halt(ep, 0);
> -}
> -
> -/**
> - * usb_ep_set_wedge - sets the halt feature and ignores clear requests
> - * @ep: the endpoint being wedged
> - *
> - * Use this to stall an endpoint and ignore CLEAR_FEATURE(HALT_ENDPOINT)
> - * requests. If the gadget driver clears the halt status, it will
> - * automatically unwedge the endpoint.
> - *
> - * Returns zero on success, else negative errno.
> - */
> -static inline int
> -usb_ep_set_wedge(struct usb_ep *ep)
> -{
> -	if (ep->ops->set_wedge)
> -		return ep->ops->set_wedge(ep);
> -	else
> -		return ep->ops->set_halt(ep, 1);
> -}
> -
> -/**
> - * usb_ep_fifo_status - returns number of bytes in fifo, or error
> - * @ep: the endpoint whose fifo status is being checked.
> - *
> - * FIFO endpoints may have "unclaimed data" in them in certain cases,
> - * such as after aborted transfers.  Hosts may not have collected all
> - * the IN data written by the gadget driver (and reported by a request
> - * completion).  The gadget driver may not have collected all the data
> - * written OUT to it by the host.  Drivers that need precise handling for
> - * fault reporting or recovery may need to use this call.
> - *
> - * This returns the number of such bytes in the fifo, or a negative
> - * errno if the endpoint doesn't use a FIFO or doesn't support such
> - * precise handling.
> - */
> +{ return 0; }
> +static inline int usb_ep_set_wedge(struct usb_ep *ep)
> +{ return 0; }
>  static inline int usb_ep_fifo_status(struct usb_ep *ep)
> -{
> -	if (ep->ops->fifo_status)
> -		return ep->ops->fifo_status(ep);
> -	else
> -		return -EOPNOTSUPP;
> -}
> -
> -/**
> - * usb_ep_fifo_flush - flushes contents of a fifo
> - * @ep: the endpoint whose fifo is being flushed.
> - *
> - * This call may be used to flush the "unclaimed data" that may exist in
> - * an endpoint fifo after abnormal transaction terminations.  The call
> - * must never be used except when endpoint is not being used for any
> - * protocol translation.
> - */
> +{ return 0; }
>  static inline void usb_ep_fifo_flush(struct usb_ep *ep)
> -{
> -	if (ep->ops->fifo_flush)
> -		ep->ops->fifo_flush(ep);
> -}
> -
> +{ }
> +#endif /* USB_GADGET */
>  
>  /*-------------------------------------------------------------------------*/
>  
> @@ -760,251 +502,44 @@ static inline int gadget_is_otg(struct usb_gadget *g)
>  #endif
>  }
>  
> -/**
> - * usb_gadget_frame_number - returns the current frame number
> - * @gadget: controller that reports the frame number
> - *
> - * Returns the usb frame number, normally eleven bits from a SOF packet,
> - * or negative errno if this device doesn't support this capability.
> - */
> -static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
> -{
> -	return gadget->ops->get_frame(gadget);
> -}
> +/*-------------------------------------------------------------------------*/
>  
> -/**
> - * usb_gadget_wakeup - tries to wake up the host connected to this gadget
> - * @gadget: controller used to wake up the host
> - *
> - * Returns zero on success, else negative error code if the hardware
> - * doesn't support such attempts, or its support has not been enabled
> - * by the usb host.  Drivers must return device descriptors that report
> - * their ability to support this, or hosts won't enable it.
> - *
> - * This may also try to use SRP to wake the host and start enumeration,
> - * even if OTG isn't otherwise in use.  OTG devices may also start
> - * remote wakeup even when hosts don't explicitly enable it.
> - */
> +#if IS_ENABLED(CONFIG_USB_GADGET)
> +int usb_gadget_frame_number(struct usb_gadget *gadget);
> +int usb_gadget_wakeup(struct usb_gadget *gadget);
> +int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
> +int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
> +int usb_gadget_vbus_connect(struct usb_gadget *gadget);
> +int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
> +int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
> +int usb_gadget_connect(struct usb_gadget *gadget);
> +int usb_gadget_disconnect(struct usb_gadget *gadget);
> +int usb_gadget_deactivate(struct usb_gadget *gadget);
> +int usb_gadget_activate(struct usb_gadget *gadget);
> +#else
> +static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
> +{ return 0; }
>  static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->wakeup)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->wakeup(gadget);
> -}
> -
> -/**
> - * usb_gadget_set_selfpowered - sets the device selfpowered feature.
> - * @gadget:the device being declared as self-powered
> - *
> - * this affects the device status reported by the hardware driver
> - * to reflect that it now has a local power supply.
> - *
> - * returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->set_selfpowered)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->set_selfpowered(gadget, 1);
> -}
> -
> -/**
> - * usb_gadget_clear_selfpowered - clear the device selfpowered feature.
> - * @gadget:the device being declared as bus-powered
> - *
> - * this affects the device status reported by the hardware driver.
> - * some hardware may not support bus-powered operation, in which
> - * case this feature's value can never change.
> - *
> - * returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->set_selfpowered)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->set_selfpowered(gadget, 0);
> -}
> -
> -/**
> - * usb_gadget_vbus_connect - Notify controller that VBUS is powered
> - * @gadget:The device which now has VBUS power.
> - * Context: can sleep
> - *
> - * This call is used by a driver for an external transceiver (or GPIO)
> - * that detects a VBUS power session starting.  Common responses include
> - * resuming the controller, activating the D+ (or D-) pullup to let the
> - * host detect that a USB device is attached, and starting to draw power
> - * (8mA or possibly more, especially after SET_CONFIGURATION).
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->vbus_session)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_session(gadget, 1);
> -}
> -
> -/**
> - * usb_gadget_vbus_draw - constrain controller's VBUS power usage
> - * @gadget:The device whose VBUS usage is being described
> - * @mA:How much current to draw, in milliAmperes.  This should be twice
> - *	the value listed in the configuration descriptor bMaxPower field.
> - *
> - * This call is used by gadget drivers during SET_CONFIGURATION calls,
> - * reporting how much power the device may consume.  For example, this
> - * could affect how quickly batteries are recharged.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
> -{
> -	if (!gadget->ops->vbus_draw)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_draw(gadget, mA);
> -}
> -
> -/**
> - * usb_gadget_vbus_disconnect - notify controller about VBUS session end
> - * @gadget:the device whose VBUS supply is being described
> - * Context: can sleep
> - *
> - * This call is used by a driver for an external transceiver (or GPIO)
> - * that detects a VBUS power session ending.  Common responses include
> - * reversing everything done in usb_gadget_vbus_connect().
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
> -{
> -	if (!gadget->ops->vbus_session)
> -		return -EOPNOTSUPP;
> -	return gadget->ops->vbus_session(gadget, 0);
> -}
> -
> -/**
> - * usb_gadget_connect - software-controlled connect to USB host
> - * @gadget:the peripheral being connected
> - *
> - * Enables the D+ (or potentially D-) pullup.  The host will start
> - * enumerating this gadget when the pullup is active and a VBUS session
> - * is active (the link is powered).  This pullup is always enabled unless
> - * usb_gadget_disconnect() has been used to disable it.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_connect(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (!gadget->ops->pullup)
> -		return -EOPNOTSUPP;
> -
> -	if (gadget->deactivated) {
> -		/*
> -		 * If gadget is deactivated we only save new state.
> -		 * Gadget will be connected automatically after activation.
> -		 */
> -		gadget->connected = true;
> -		return 0;
> -	}
> -
> -	ret = gadget->ops->pullup(gadget, 1);
> -	if (!ret)
> -		gadget->connected = 1;
> -	return ret;
> -}
> -
> -/**
> - * usb_gadget_disconnect - software-controlled disconnect from USB host
> - * @gadget:the peripheral being disconnected
> - *
> - * Disables the D+ (or potentially D-) pullup, which the host may see
> - * as a disconnect (when a VBUS session is active).  Not all systems
> - * support software pullup controls.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (!gadget->ops->pullup)
> -		return -EOPNOTSUPP;
> -
> -	if (gadget->deactivated) {
> -		/*
> -		 * If gadget is deactivated we only save new state.
> -		 * Gadget will stay disconnected after activation.
> -		 */
> -		gadget->connected = false;
> -		return 0;
> -	}
> -
> -	ret = gadget->ops->pullup(gadget, 0);
> -	if (!ret)
> -		gadget->connected = 0;
> -	return ret;
> -}
> -
> -/**
> - * usb_gadget_deactivate - deactivate function which is not ready to work
> - * @gadget: the peripheral being deactivated
> - *
> - * This routine may be used during the gadget driver bind() call to prevent
> - * the peripheral from ever being visible to the USB host, unless later
> - * usb_gadget_activate() is called.  For example, user mode components may
> - * need to be activated before the system can talk to hosts.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
> -{
> -	int ret;
> -
> -	if (gadget->deactivated)
> -		return 0;
> -
> -	if (gadget->connected) {
> -		ret = usb_gadget_disconnect(gadget);
> -		if (ret)
> -			return ret;
> -		/*
> -		 * If gadget was being connected before deactivation, we want
> -		 * to reconnect it in usb_gadget_activate().
> -		 */
> -		gadget->connected = true;
> -	}
> -	gadget->deactivated = true;
> -
> -	return 0;
> -}
> -
> -/**
> - * usb_gadget_activate - activate function which is not ready to work
> - * @gadget: the peripheral being activated
> - *
> - * This routine activates gadget which was previously deactivated with
> - * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
> - *
> - * Returns zero on success, else negative errno.
> - */
> +{ return 0; }
>  static inline int usb_gadget_activate(struct usb_gadget *gadget)
> -{
> -	if (!gadget->deactivated)
> -		return 0;
> -
> -	gadget->deactivated = false;
> -
> -	/*
> -	 * If gadget has been connected before deactivation, or became connected
> -	 * while it was being deactivated, we call usb_gadget_connect().
> -	 */
> -	if (gadget->connected)
> -		return usb_gadget_connect(gadget);
> -
> -	return 0;
> -}
> +{ return 0; }
> +#endif /* CONFIG_USB_GADGET */
>  
>  /*-------------------------------------------------------------------------*/
>  
> -- 
> 2.8.3
> 
> 
> 
> -- 
> balbi



-- 

Best Regards,
Peter Chen
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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Felipe Balbi]

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Hi,

Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
>> > Would you consider only keeps vbus and pull dp API at gadget.h, and move
>> > out others gadget APIs which is dedicated for gadget function?
>> 
>> no, sorry :-) All these drivers depend on the gadget API to work. For
>> host-only builds, they'll still work because of the stub implemented in
>> gadget.h.
>
> Do you want these drivers to add dependency on GADGET at Kconfig
> or not? If you want, we don't need stub at gadget.h since the gadget

just look at what the patch does:

if USB_GADGET=m, then NOP must be m too. if USB_GADGET=y, then NOP can
be y or m.

> will be built if these driver is built. I assume you don't want, then
> that's ok, we don't need to change anything on Kconfig to fix build
> issue.

There was, anyway, a bug in my original patch in that it didn't provide
stubs for cases were USB_GADGET=n. That bug is now fixed, I'll still
wait a couple days for any 0-day build problems.

>> Also, did you test the version I've apended to previous email? I noticed
>> that had one extra mistake which I correct in the version below:
>> 
>
> Sorry, I did not try since I still have some questions for solution:)

heh. You're not even willing to try a patch, rather than complaining
about pointless stuff all day. Thanks

-- 
balbi

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Re: [balbi-usb:testing/next 64/67] phy-generic.c:undefined reference to `usb_gadget_vbus_connect'

[Peter Chen]

On Wed, Jun 08, 2016 at 01:32:29PM +0300, Felipe Balbi wrote:
> 
> Hi,
> 
> Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:
> >> > Would you consider only keeps vbus and pull dp API at gadget.h, and move
> >> > out others gadget APIs which is dedicated for gadget function?
> >> 
> >> no, sorry :-) All these drivers depend on the gadget API to work. For
> >> host-only builds, they'll still work because of the stub implemented in
> >> gadget.h.
> >
> > Do you want these drivers to add dependency on GADGET at Kconfig
> > or not? If you want, we don't need stub at gadget.h since the gadget
> 
> just look at what the patch does:
> 
> if USB_GADGET=m, then NOP must be m too. if USB_GADGET=y, then NOP can
> be y or m.
> 
> > will be built if these driver is built. I assume you don't want, then
> > that's ok, we don't need to change anything on Kconfig to fix build
> > issue.
> 
> There was, anyway, a bug in my original patch in that it didn't provide
> stubs for cases were USB_GADGET=n. That bug is now fixed, I'll still
> wait a couple days for any 0-day build problems.
> 
> >> Also, did you test the version I've apended to previous email? I noticed
> >> that had one extra mistake which I correct in the version below:
> >> 
> >
> > Sorry, I did not try since I still have some questions for solution:)
> 
> heh. You're not even willing to try a patch, rather than complaining
> about pointless stuff all day. Thanks
> 

The reason why I did not try your patch is: I don't think the PHY needs
to depend on GADGET since your 1st patch like below:

+       depends on USB_GADGET=y || USB_GADGET=NOP_USB_XCEIV
+       depends on NOP_USB_XCEIV

But look at your the newest patch, you have fixed it like below:
+ 	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, NOP can't be
built-in

I agree with that since PHY can not depend on GADGET if it does not use
gadget APIs.

After trying your patch, you only fixed NOP PHY build issue (chipidea
build issue is fixed too), but without for other code. You may need to
fix all like my last grep:

b29397@shlinux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_vbus_connect"
./drivers/phy/phy-twl4030-usb.c:559:		 * REVISIT usb_gadget_vbus_connect(...) as needed, ditto
./drivers/usb/phy/phy-gpio-vbus-usb.c:126:		usb_gadget_vbus_connect(gpio_vbus->phy.otg->gadget);
./drivers/usb/phy/phy-tahvo.c:89:				usb_gadget_vbus_connect(tu->phy.otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:929:	usb_gadget_vbus_connect(isp->phy.otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:1466:		usb_gadget_vbus_connect(otg->gadget);
./drivers/usb/phy/phy-generic.c:122:			usb_gadget_vbus_connect(otg->gadget);
./drivers/usb/phy/phy-generic.c:190:		usb_gadget_vbus_connect(gadget);
./drivers/usb/phy/phy-msm-usb.c:783:		usb_gadget_vbus_connect(phy->otg->gadget);
./drivers/usb/phy/phy-mv-usb.c:234:		usb_gadget_vbus_connect(otg->gadget);
./drivers/usb/chipidea/otg.c:133:		usb_gadget_vbus_connect(&ci->gadget);
./drivers/usb/chipidea/otg.c:138:		usb_gadget_vbus_connect(&ci->gadget);
./drivers/usb/chipidea/udc.c:1964:		usb_gadget_vbus_connect(&ci->gadget);
./drivers/usb/chipidea/otg_fsm.c:567:		usb_gadget_vbus_connect(&ci->gadget);
b29397@shlinux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_vbus_disconnect"
./drivers/usb/phy/phy-gpio-vbus-usb.c:145:		usb_gadget_vbus_disconnect(gpio_vbus->phy.otg->gadget);
./drivers/usb/phy/phy-gpio-vbus-usb.c:200:		usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-tahvo.c:108:				usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
./drivers/usb/phy/phy-tahvo.c:165:		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
./drivers/usb/phy/phy-tahvo.c:175:		usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:312:	return usb_gadget_vbus_disconnect(isp->phy.otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:989:				usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-isp1301-omap.c:1342:		usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-generic.c:133:			usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-fsl-usb.c:622:		usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/phy/phy-msm-usb.c:786:		usb_gadget_vbus_disconnect(phy->otg->gadget);
./drivers/usb/phy/phy-mv-usb.c:236:		usb_gadget_vbus_disconnect(otg->gadget);
./drivers/usb/chipidea/otg.c:140:		usb_gadget_vbus_disconnect(&ci->gadget);
./drivers/usb/chipidea/otg_fsm.c:569:		usb_gadget_vbus_disconnect(&ci->gadget);
b29397@shlinux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_connect"
./drivers/power/isp1704_charger.c:272:				usb_gadget_connect(isp->phy->otg->gadget);
./drivers/usb/gadget/udc/fsl_udc_core.c:1215: * this func is used by usb_gadget_connect/disconnet
./drivers/usb/gadget/udc/udc-core.c:262:		usb_gadget_connect(udc->gadget);
./drivers/usb/gadget/udc/udc-core.c:671:		usb_gadget_connect(udc->gadget);
./drivers/usb/chipidea/udc.c:1593: * this func is used by usb_gadget_connect/disconnet
b29397@shlinux2:~/work/projects/usb$ find . -name *.c | xargs grep -rn "usb_gadget_disconnect"
./drivers/power/isp1704_charger.c:302:			usb_gadget_disconnect(isp->phy->otg->gadget);
./drivers/power/isp1704_charger.c:504:		usb_gadget_disconnect(isp->phy->otg->gadget);
./drivers/usb/gadget/udc/udc-core.c:264:		usb_gadget_disconnect(udc->gadget);
./drivers/usb/gadget/udc/udc-core.c:502:	usb_gadget_disconnect(udc->gadget);
./drivers/usb/gadget/udc/udc-core.c:673:		usb_gadget_disconnect(udc->gadget);
./drivers/usb/gadget/composite.c:974: * Drivers must call usb_gadget_disconnect before calling this function
./drivers/usb/gadget/composite.c:2296: * the host, unless one of its components invokes usb_gadget_disconnect()

-- 

Best Regards,
Peter Chen
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