Hi Peter, I am currently trying to come up with a upstreamable solution for USB device/host switch for our NXP i.MX 7 CoM (Colibri iMX7). My colleague Sanchayan already posted on the mailing list in a earlier attempt for our Colibri VFxx modules (NXP Vybrid): http://www.spinics.net/lists/linux-usb/msg140810.html The situation is very similar: The device is not OTG capable, but just allows to use a Micro-USB connector as Host when using a OTG cable. VBUS is enabled in hardware depending on ID-Pin. We have a single 3.3V input to the module "usbc_det". Back then your advice was to wait for the DCD framework, however, reading up on the mailing list discussion it seems that this did not make it mainline in a form it would be easily usable with the Chipidea IP: https://patchwork.kernel.org/patch/9172269/ Downstream we currently use a custom "state machine" which directly calls ci_role_stop/start and usb_gadget_vbus_(dis)connect: http://git.toradex.com/cgit/linux-toradex.git/commit/drivers/usb/chipidea/core.c?h=toradex_4.1-2.0.x-imx-next&id=1f43d373946ee34ce0cfeb667a9aa48d6995bfea I tried to use the Chipidea OTG FSM and extcon. The device tree bindings state: > - extcon: phandles to external connector devices. First phandle should point to > external connector, which provide "USB" cable events, the second should point > to external connector device, which provide "USB-HOST" cable events. If one > of the external connector devices is not required, empty <0> phandle should > be specified. It sounds like any of the two extcon are optional, also in drivers/usb/chipidea/core.c a comment notes: "Each one of them is not mandatory" On Colibri iMX7 the usbc_det is also connected to USB_OTG1_VBUS, and it leads to a proper B Session Valid in OTGSC registers. So I tried specifying ID only (since VBUS is switched in hardware and can be detected through B Session Valid), but this seems not to be stuck in the OTG FSM (with an additional debug print in ci_otg_fsm_event): [ 264.327871] ci_otg_fsm_irq [ 264.333153] ci_hdrc ci_hdrc.0: ci_otg_fsm_event a_wait_vrise [ 264.347984] ci_cable_notifier, event 0 [ 264.354329] ci_otg_fsm_irq [ 265.360930] ci_hdrc ci_hdrc.0: remove, state 4 [ 265.367862] usb usb1: USB disconnect, device number 1 [ 265.380912] ci_hdrc ci_hdrc.0: USB bus 1 deregistered It seems to me that the CI OTG FSM is too complex for what I am trying to achieve. Any advice how I should go about it? -- Stefan -- 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
