From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Quadros Subject: Re: [PATCH v7 03/14] usb: hcd.h: Add OTG to HCD interface Date: Tue, 10 May 2016 10:34:49 +0300 Message-ID: <57318F19.7000506@ti.com> References: <1462191537-10314-1-git-send-email-rogerq@ti.com> <1462191537-10314-4-git-send-email-rogerq@ti.com> <20160506094103.GF32359@shlinux2.ap.freescale.net> <57305C42.90300@ti.com> <20160510031401.GA3748@shlinux2.ap.freescale.net> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160510031401.GA3748@shlinux2.ap.freescale.net> Sender: linux-kernel-owner@vger.kernel.org To: Peter Chen 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 List-Id: devicetree@vger.kernel.org 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 >>>> Acked-by: Peter Chen >>> >>> 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 >>> >