On Fri, May 13, 2016 at 01:03:14PM +0300, Roger Quadros wrote: > Hi, > > This series centralizes OTG/Dual-role functionality in the kernel. > As of now I've got Dual-role functionality working pretty reliably on > dra7-evm and am437x-gp-evm. > NOTE: my am437x-gp-evm broke so I couldn't test v8 on it. > But the changes since v7 are trivial and shouldn't impact am437x-gp-evm. > > DWC3 controller and platform related patches will be sent separately. > > Series is based on v4.6-rc1 and depends on first 2 patches of [1] > [1] - OTG fsm cleanup - https://lkml.org/lkml/2016/3/30/186 > > Why?: > ---- > > Currently there is no central location where OTG/dual-role functionality is > implemented in the Linux USB stack and every USB controller driver is > doing their own thing for OTG/dual-role. We can benefit from code-reuse > and simplicity by adding the OTG/dual-role core driver. > > Newer OTG cores support standard host interface (e.g. xHCI) so > host and gadget functionality are no longer closely knit like older > cores. There needs to be a way to co-ordinate the operation of the > host and gadget controllers in dual-role mode. i.e. to stop and start them > from a central location. This central location should be the > USB OTG/dual-role core. > > Host and gadget controllers might be sharing resources and can't > be always running. One has to be stopped for the other to run. > This couldn't be done till now but can be done from the OTG core. > > What?: > ----- > > The OTG/dual-role core consists of a set of APIs that allow > registration of OTG controller device and OTG capable host and gadget > controllers. > > - The OTG controller driver can provide the OTG capabilities and the > Finite State Machine work function via 'struct usb_otg_config' > at the time of registration i.e. usb_otg_register(); > > struct usb_otg *usb_otg_register(struct device *dev, > struct usb_otg_config *config); > int usb_otg_unregister(struct device *dev); > /** > * struct usb_otg_config - otg controller configuration > * @caps: otg capabilities of the controller > * @ops: otg fsm operations > * @otg_work: optional custom otg state machine work function > */ > struct usb_otg_config { > struct usb_otg_caps *otg_caps; > struct otg_fsm_ops *fsm_ops; > void (*otg_work)(struct work_struct *work); > }; > > The dual-role state machine is built-into the OTG core so nothing > special needs to be provided if only dual-role functionality is desired. > The low level OTG controller driver ops are povided via > 'struct otg_fsm_ops *fsm_ops' in the 'struct usb_otg_config'. > > After registration, the OTG core waits for host, gadget controller > and the gadget function driver to be registered. Once all resources are > available it instantiates the Finite State Machine (FSM). > The host/gadget controllers are started/stopped according to the FSM. > > - Host and gadget controllers that are a part of OTG/dual-role port must > use the OTG core provided APIs to add/remove the host/gadget. > i.e. hosts must use usb_otg_add_hcd() usb_otg_remove_hcd(),, > gadgets must use usb_otg_add_gadget_udc() usb_del_gadget_udc(). > This ensures that the host and gadget controllers are not started till > the state machine is ready and the right bus conditions are met. > It also allows the host and gadget controllers to provide the OTG > controller device to link them together. For Device tree boots > the related OTG controller is automatically picked up via the > 'otg-controller' property in the Host/Gadget controller nodes. > > int usb_otg_add_hcd(struct usb_hcd *hcd, > unsigned int irqnum, unsigned long irqflags, > struct device *otg_dev); > void usb_otg_remove_hcd(struct usb_hcd *hcd); > > int usb_otg_add_gadget_udc(struct device *parent, > struct usb_gadget *gadget, > struct device *otg_dev); > usb_del_gadget_udc() must be used for removal. > > > - During the lifetime of the FSM, the OTG controller driver can provide > inputs event changes using usb_otg_sync_inputs(). The OTG core will > then schedule the FSM work function (or internal dual-role state machine) > to update the FSM state. The FSM then calls the OTG controller > operations (fsm_ops) as necessary. > void usb_otg_sync_inputs(struct usb_otg *otg); > > - The following 2 functions are provided as helpers for use by the > OTG controller driver to start/stop the host/gadget controllers. > int usb_otg_start_host(struct usb_otg *otg, int on); > int usb_otg_start_gadget(struct usb_otg *otg, int on); > > - The following function is provided for use by the USB host stack > to sync OTG related events to the OTG state machine. > e.g. change in host_bus->b_hnp_enable, gadget->b_hnp_enable > int usb_otg_kick_fsm(struct device *otg_device); > > Changelog: > --------- > v8: > - split out start/stop gadget and connect/disconnect operations. > - make CONFIG_OTG dpend on CONFIG_USB_GADGET as well apart from CONFIG_USB > - use create_freezable_workqueue() for OTG work as per Peter's suggestion. > - remove usb-otg.h as we're not initializing any OTG timers. > - don't include unnecessary headers in usb-otg.c (i.e. hrtimer.h & ktime.h) > Since you have agreed to move CONFIG_USB_OTG out of HCD, I suggest you can have a folder to put current OTG and OTG_FSM stuffs under the root of usb folder, it can benefit the user who wants to add their dual-role switch driver or OTG driver. What do you think? Peter > v7: > - added dual-role support for host controllers requiring a companion > controller. e.g. EHCI + OHCI. > - added of_usb_get_otg() to get the OTG controller device > from the USB controller's device node. > - addressed review comments. > > v6: > - added otg specific APIs for host/gadget registration. behaviour of > original host/gadget API remains unchanged. Platform devices can now > pass the otg device explicitly while registering host/gadget. > - moved hcd specific operations from struct otg_fsm to struct hcd_ops. > - made struct usb_otg mandatory for all otg related APIs. > - allow otg controller to provide it's own otg_work function so that > it can implement it's own state machine. > - removed otg fsm and timers from usb-otg.c. Only dual-role state machine > is implemented. > - vbus is controlled in the dual-role state machine. > - PM runtime is used around drd_statemachine(). > - added otg_dev to xhci platform data to allow platform code to specify > the otg controller tied to the xhci host controller. > > v5: Internal version. Not sent to mailing list > > v4: > - Added DT support for tying otg-controller to host and gadget > controllers. For DT we no longer have the constraint that > OTG controller needs to be parent of host and gadget. They can be > tied together using the "otg-controller" property. > - Relax the requirement for DT case that otg controller must register > before host/gadget. We maintain a wait list of host/gadget devices > waiting on the otg controller. > - Use a single struct usb_otg for otg data. > - Don't override host/gadget start/stop APIs. Let the controller > drivers do what they want as they know best. Helper API is provided > for controller start/stop that controller driver can use. > - Introduce struct usb_otg_config to pass the otg capabilities, > otg ops and otg timer timeouts during otg controller registration. > - rebased on Greg's usb.git/usb-next > > v3: > - all otg related definations now in otg.h > - single kernel config USB_OTG to enable OTG core and FSM. > - resolved symbol dependency issues. > - use dev_vdbg instead of VDBG() in usb-otg-fsm.c > - rebased on v4.2-rc1 > > v2: > - Use add/remove_hcd() instead of start/stop_hcd() to enable/disable > the host controller > - added dual-role-device (DRD) state machine which is a much simpler > mode of operation when compared to OTG. Here we don't support fancy > OTG features like HNP, SRP, on the fly role-swap. The mode of operation > is determined based on ID pin (cable type) and the role doesn't change > till the cable type changes. > > -- > cheers, > -roger > > Roger Quadros (13): > usb: hcd: Initialize hcd->flags to 0 > usb: otg-fsm: Prevent build warning "VDBG" redefined > usb: hcd.h: Add OTG to HCD interface > usb: otg-fsm: use usb_otg wherever possible > usb: otg-fsm: move host controller operations into usb_otg->hcd_ops > usb: gadget.h: Add OTG to gadget interface > usb: otg: get rid of CONFIG_USB_OTG_FSM in favour of CONFIG_USB_OTG > usb: otg: add OTG/dual-role core > usb: of: add an API to get OTG device from USB controller node > usb: otg: use dev_dbg() instead of VDBG() > usb: hcd: Adapt to OTG core > usb: gadget: udc: adapt to OTG core > usb: host: xhci-plat: Add otg device to platform data > > Yoshihiro Shimoda (1): > usb: otg: add hcd companion support > > Documentation/devicetree/bindings/usb/generic.txt | 6 + > Documentation/usb/chipidea.txt | 2 +- > drivers/usb/chipidea/Makefile | 2 +- > drivers/usb/chipidea/ci.h | 3 +- > drivers/usb/chipidea/core.c | 14 +- > drivers/usb/chipidea/debug.c | 2 +- > drivers/usb/chipidea/otg_fsm.c | 176 ++-- > drivers/usb/chipidea/otg_fsm.h | 2 +- > drivers/usb/chipidea/udc.c | 17 +- > drivers/usb/common/Makefile | 3 +- > drivers/usb/common/common.c | 27 + > drivers/usb/common/usb-otg-fsm.c | 203 ++-- > drivers/usb/common/usb-otg.c | 1056 +++++++++++++++++++++ > drivers/usb/core/Kconfig | 12 +- > drivers/usb/core/hcd.c | 56 ++ > drivers/usb/gadget/udc/udc-core.c | 194 +++- > drivers/usb/host/xhci-plat.c | 35 +- > drivers/usb/phy/Kconfig | 2 +- > drivers/usb/phy/phy-fsl-usb.c | 155 +-- > drivers/usb/phy/phy-fsl-usb.h | 3 +- > include/linux/usb/gadget.h | 22 + > include/linux/usb/hcd.h | 29 + > include/linux/usb/of.h | 9 + > include/linux/usb/otg-fsm.h | 154 +-- > include/linux/usb/otg.h | 264 +++++- > include/linux/usb/xhci_pdriver.h | 3 + > 26 files changed, 2013 insertions(+), 438 deletions(-) > create mode 100644 drivers/usb/common/usb-otg.c > > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
