| Message ID | 1462191537-10314-4-git-send-email-rogerq@ti.com |
|---|---|
| State | Superseded |
| Headers | show |
On 10/05/16 06:14, Peter Chen wrote: > On Mon, May 09, 2016 at 12:45:38PM +0300, Roger Quadros wrote: >> On 06/05/16 12:41, Peter Chen wrote: >>> On Mon, May 02, 2016 at 03:18:46PM +0300, Roger Quadros wrote: >>>> The OTG core will use struct otg_hcd_ops to interface >>>> with the HCD controller. >>>> >>>> The main purpose of this interface is to avoid directly >>>> calling HCD APIs from the OTG core as they >>>> wouldn't be defined in the built-in symbol table if >>>> CONFIG_USB is m. >>>> >>>> Signed-off-by: Roger Quadros <rogerq@ti.com> >>>> Acked-by: Peter Chen <peter.chen@nxp.com> >>> >>> Roger, after thinking more, I still think current dependency between >>> OTG, HCD and gadget are too complicated. Since the OTG can't work >>> if it is built as module, I suggest letting OTG depends on HCD && >>> USB_GADGET, and it is a boolean, in that case, we don't need to >>> export any HCD and gadget ops, things will be much simpler. >>> What's your opinion? >> >> How will it work if HCD and USB_GADGET are modules and OTG is built-in? >> > > The OTG will not be compiled at this situation, since it is boolean. > In fact, like I mentioned at above, OTG or USB function can't work if > it is built as module. Isn't this a limitation? As per the current implementation dual role works fine even with both USB_GADGET and HCD as module. In the real world it is unlikely that GADGET and HCD will be built-in. cheers, -roger > > Peter >> cheers, >> -roger >> >>> >>> Peter >>> >>>> --- >>>> include/linux/usb/hcd.h | 24 ++++++++++++++++++++++++ >>>> 1 file changed, 24 insertions(+) >>>> >>>> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h >>>> index b98f831..861ccaa 100644 >>>> --- a/include/linux/usb/hcd.h >>>> +++ b/include/linux/usb/hcd.h >>>> @@ -399,6 +399,30 @@ struct hc_driver { >>>> >>>> }; >>>> >>>> +/** >>>> + * struct otg_hcd_ops - Interface between OTG core and HCD >>>> + * >>>> + * Provided by the HCD core to allow the OTG core to interface with the HCD >>>> + * >>>> + * @add: function to add the HCD >>>> + * @remove: function to remove the HCD >>>> + * @usb_bus_start_enum: function to immediately start bus enumeration >>>> + * @usb_control_msg: function to build and send of a control urb >>>> + * @usb_hub_find_child: function to get pointer to the child device >>>> + */ >>>> +struct otg_hcd_ops { >>>> + int (*add)(struct usb_hcd *hcd, >>>> + unsigned int irqnum, unsigned long irqflags); >>>> + void (*remove)(struct usb_hcd *hcd); >>>> + int (*usb_bus_start_enum)(struct usb_bus *bus, unsigned int port_num); >>>> + int (*usb_control_msg)(struct usb_device *dev, unsigned int pipe, >>>> + __u8 request, __u8 requesttype, __u16 value, >>>> + __u16 index, void *data, __u16 size, >>>> + int timeout); >>>> + struct usb_device * (*usb_hub_find_child)(struct usb_device *hdev, >>>> + int port1); >>>> +}; >>>> + >>>> static inline int hcd_giveback_urb_in_bh(struct usb_hcd *hcd) >>>> { >>>> return hcd->driver->flags & HCD_BH; >>>> -- >>>> 2.7.4 >>>> >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in >>>> the body of a message to majordomo@vger.kernel.org >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >
On 10/05/16 11:12, Felipe Balbi wrote: > > Hi, > > Roger Quadros <rogerq@ti.com> writes: >> On 10/05/16 06:14, Peter Chen wrote: >>> On Mon, May 09, 2016 at 12:45:38PM +0300, Roger Quadros wrote: >>>> On 06/05/16 12:41, Peter Chen wrote: >>>>> On Mon, May 02, 2016 at 03:18:46PM +0300, Roger Quadros wrote: >>>>>> The OTG core will use struct otg_hcd_ops to interface >>>>>> with the HCD controller. >>>>>> >>>>>> The main purpose of this interface is to avoid directly >>>>>> calling HCD APIs from the OTG core as they >>>>>> wouldn't be defined in the built-in symbol table if >>>>>> CONFIG_USB is m. >>>>>> >>>>>> Signed-off-by: Roger Quadros <rogerq@ti.com> >>>>>> Acked-by: Peter Chen <peter.chen@nxp.com> >>>>> >>>>> Roger, after thinking more, I still think current dependency between >>>>> OTG, HCD and gadget are too complicated. Since the OTG can't work >>>>> if it is built as module, I suggest letting OTG depends on HCD && >>>>> USB_GADGET, and it is a boolean, in that case, we don't need to >>>>> export any HCD and gadget ops, things will be much simpler. >>>>> What's your opinion? >>>> >>>> How will it work if HCD and USB_GADGET are modules and OTG is built-in? >>>> >>> >>> The OTG will not be compiled at this situation, since it is boolean. >>> In fact, like I mentioned at above, OTG or USB function can't work if >>> it is built as module. >> >> Isn't this a limitation? > > I agree, it should work built-in or module. > >> As per the current implementation dual role works fine even with both >> USB_GADGET and HCD as module. >> >> In the real world it is unlikely that GADGET and HCD will be built-in. > > we can't make this assumption, however :-) > Agreed, we need to make sure it works with all combinations. cheers, -roger
On 10/05/16 11:03, Jun Li wrote: > Hi > >> -----Original Message----- >> From: Roger Quadros [mailto:rogerq@ti.com] >> Sent: Tuesday, May 10, 2016 3:35 PM >> To: Peter Chen <hzpeterchen@gmail.com> >> Cc: peter.chen@freescale.com; stern@rowland.harvard.edu; balbi@kernel.org; >> gregkh@linuxfoundation.org; dan.j.williams@intel.com; jun.li@freescale.com; >> mathias.nyman@linux.intel.com; tony@atomide.com; Joao.Pinto@synopsys.com; >> abrestic@chromium.org; yoshihiro.shimoda.uh@renesas.com; linux- >> usb@vger.kernel.org; linux-kernel@vger.kernel.org; linux- >> omap@vger.kernel.org; devicetree@vger.kernel.org >> Subject: Re: [PATCH v7 03/14] usb: hcd.h: Add OTG to HCD interface >> >> On 10/05/16 06:14, Peter Chen wrote: >>> On Mon, May 09, 2016 at 12:45:38PM +0300, Roger Quadros wrote: >>>> On 06/05/16 12:41, Peter Chen wrote: >>>>> On Mon, May 02, 2016 at 03:18:46PM +0300, Roger Quadros wrote: >>>>>> The OTG core will use struct otg_hcd_ops to interface with the HCD >>>>>> controller. >>>>>> >>>>>> The main purpose of this interface is to avoid directly calling HCD >>>>>> APIs from the OTG core as they wouldn't be defined in the built-in >>>>>> symbol table if CONFIG_USB is m. >>>>>> >>>>>> Signed-off-by: Roger Quadros <rogerq@ti.com> >>>>>> Acked-by: Peter Chen <peter.chen@nxp.com> >>>>> >>>>> Roger, after thinking more, I still think current dependency between >>>>> OTG, HCD and gadget are too complicated. Since the OTG can't work if >>>>> it is built as module, I suggest letting OTG depends on HCD && >>>>> USB_GADGET, and it is a boolean, in that case, we don't need to >>>>> export any HCD and gadget ops, things will be much simpler. >>>>> What's your opinion? >>>> >>>> How will it work if HCD and USB_GADGET are modules and OTG is built-in? >>>> >>> >>> The OTG will not be compiled at this situation, since it is boolean. >>> In fact, like I mentioned at above, OTG or USB function can't work if >>> it is built as module. >> >> Isn't this a limitation? >> As per the current implementation dual role works fine even with both >> USB_GADGET and HCD as module. > > My understand: only make sense for pass build, host can't work before > gadget modules loaded; gadget can't work before hcd loaded, nothing > can work before all drivers are loaded. I can make OTG depend on GADGET and HCD, no issue with that. But we can't get rid of the OTG to HCD/Gadged interfaces as we want things to work with GADGET and HCD as modules. > >> >> In the real world it is unlikely that GADGET and HCD will be built-in. > > Why? User enable USB_OTG means both drivers should be enabled anyway. Enabled, but not necessarily built-in. Most distributions don't have them as built-in. But let's not argue in that direction. Let's say that they can be either built-in or modules. > Even in non-OTG case, both may be built-in for machine with 2 ports > (one port is host only, the other one is peripheral only). Sure. Every system designer is free to select the configuration. > > A general question, 2 drivers depends on each other, allowable? I don't thing that's possible. Kconfig will complain. http://lxr.free-electrons.com/source/Documentation/kbuild/kconfig-language.txt#L397 cheers, -roger >>>>> >>>>>> --- >>>>>> include/linux/usb/hcd.h | 24 ++++++++++++++++++++++++ >>>>>> 1 file changed, 24 insertions(+) >>>>>> >>>>>> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h >>>>>> index b98f831..861ccaa 100644 >>>>>> --- a/include/linux/usb/hcd.h >>>>>> +++ b/include/linux/usb/hcd.h >>>>>> @@ -399,6 +399,30 @@ struct hc_driver { >>>>>> >>>>>> }; >>>>>> >>>>>> +/** >>>>>> + * struct otg_hcd_ops - Interface between OTG core and HCD >>>>>> + * >>>>>> + * Provided by the HCD core to allow the OTG core to interface >>>>>> +with the HCD >>>>>> + * >>>>>> + * @add: function to add the HCD >>>>>> + * @remove: function to remove the HCD >>>>>> + * @usb_bus_start_enum: function to immediately start bus >>>>>> +enumeration >>>>>> + * @usb_control_msg: function to build and send of a control urb >>>>>> + * @usb_hub_find_child: function to get pointer to the child >>>>>> +device */ struct otg_hcd_ops { >>>>>> + int (*add)(struct usb_hcd *hcd, >>>>>> + unsigned int irqnum, unsigned long irqflags); >>>>>> + void (*remove)(struct usb_hcd *hcd); >>>>>> + int (*usb_bus_start_enum)(struct usb_bus *bus, unsigned int >> port_num); >>>>>> + int (*usb_control_msg)(struct usb_device *dev, unsigned int >> pipe, >>>>>> + __u8 request, __u8 requesttype, __u16 value, >>>>>> + __u16 index, void *data, __u16 size, >>>>>> + int timeout); >>>>>> + struct usb_device * (*usb_hub_find_child)(struct usb_device >> *hdev, >>>>>> + int port1); >>>>>> +}; >>>>>> + >>>>>> static inline int hcd_giveback_urb_in_bh(struct usb_hcd *hcd) { >>>>>> return hcd->driver->flags & HCD_BH; >>>>>> -- >>>>>> 2.7.4 >>>>>> >>>>>> -- >>>>>> To unsubscribe from this list: send the line "unsubscribe >>>>>> linux-usb" in the body of a message to majordomo@vger.kernel.org >>>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>>>> >>>
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index b98f831..861ccaa 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -399,6 +399,30 @@ struct hc_driver { }; +/** + * struct otg_hcd_ops - Interface between OTG core and HCD + * + * Provided by the HCD core to allow the OTG core to interface with the HCD + * + * @add: function to add the HCD + * @remove: function to remove the HCD + * @usb_bus_start_enum: function to immediately start bus enumeration + * @usb_control_msg: function to build and send of a control urb + * @usb_hub_find_child: function to get pointer to the child device + */ +struct otg_hcd_ops { + int (*add)(struct usb_hcd *hcd, + unsigned int irqnum, unsigned long irqflags); + void (*remove)(struct usb_hcd *hcd); + int (*usb_bus_start_enum)(struct usb_bus *bus, unsigned int port_num); + int (*usb_control_msg)(struct usb_device *dev, unsigned int pipe, + __u8 request, __u8 requesttype, __u16 value, + __u16 index, void *data, __u16 size, + int timeout); + struct usb_device * (*usb_hub_find_child)(struct usb_device *hdev, + int port1); +}; + static inline int hcd_giveback_urb_in_bh(struct usb_hcd *hcd) { return hcd->driver->flags & HCD_BH;