RE: [PATCH] usb: dwc3: imx8mp: detect dwc3 core node via compatible string

[Felipe Balbi <balbi@kernel.org>]

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Hi,

Jun Li <jun.li@nxp.com> writes:
>> > 	val = readl(dwc3_imx->glue_base + USB_WAKEUP_CTRL);
>> >
>> > 	if ((dwc3->current_dr_role == DWC3_GCTL_PRTCAP_HOST) && dwc3->xhci)
>> > 		val |= USB_WAKEUP_EN | USB_WAKEUP_SS_CONN |
>> > 		       USB_WAKEUP_U3_EN | USB_WAKEUP_DPDM_EN;
>> > 	else if (dwc3->current_dr_role == DWC3_GCTL_PRTCAP_DEVICE)
>> > 		val |= USB_WAKEUP_EN | USB_WAKEUP_VBUS_EN |
>> > 		       USB_WAKEUP_VBUS_SRC_SESS_VAL;
>> 
>> for this, you could register a listener to the extcon notifier and update
>> these bits accordingly. With that, you would already *know* that
>> dwc3 is probed.
>
> With usb role switch class, there no extcon provider, so I think this way
> can't work for me.

perhaps role switch class could learn about notifiers ;-)

>> > static irqreturn_t dwc3_imx8mp_interrupt(int irq, void *_dwc3_imx) {
>> > 	struct dwc3_imx8mp	*dwc3_imx = _dwc3_imx;
>> > 	struct dwc3		*dwc = platform_get_drvdata(dwc3_imx->dwc3);
>> >
>> > 	if (!dwc3_imx->pm_suspended)
>> > 		return IRQ_HANDLED;
>> >
>> > 	disable_irq_nosync(dwc3_imx->irq);
>> > 	dwc3_imx->wakeup_pending = true;
>> >
>> > 	if ((dwc->current_dr_role == DWC3_GCTL_PRTCAP_HOST) && dwc->xhci)
>> > 		pm_runtime_resume(&dwc->xhci->dev);
>> > 	else if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_DEVICE)
>> > 		pm_runtime_get(dwc->dev);
>> >
>> > 	return IRQ_HANDLED;
>> > }
>> 
>> for this, maybe you need to teach dwc3 core about wakeup irqs instead. Have
>> a look dev_pm_set_dedicated_wake_irq().
>
> Good suggestion, but if extcon notifier listener can't work for me, 
> my understanding is this *teach* in glue layer driver still need
> access dwc3 core instance struct, right?

for now, maybe. But it may be better to implement a notifier method in
role switch class.

-- 
balbi

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