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. 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: --------- 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 | 1054 ++++++++++++++++++++ .../usb/{chipidea/otg_fsm.h => common/usb-otg.h} | 61 +- drivers/usb/core/Kconfig | 10 +- drivers/usb/core/hcd.c | 56 ++ drivers/usb/gadget/udc/udc-core.c | 161 ++- 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 | 20 + 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 + 27 files changed, 1989 insertions(+), 484 deletions(-) create mode 100644 drivers/usb/common/usb-otg.c copy drivers/usb/{chipidea/otg_fsm.h => common/usb-otg.h} (63%) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
