On Fri, Aug 10, 2012 at 08:12:07AM +0000, Chen Peter-B29397 wrote:
>
> > > So, the others are usb_state not usb_otg_state. Then, when we
> > generalize
> > > otg driver, what kinds of **states** do you plan to use to stand for
> > otg
> > > state machine? Besides, if we name something different with spec, does
> > it
> > > will confuse the users?
> >
> > We could have just a single enum usb_state defined something like:
> >
> > enum usb_otg_state {
> > USB_STATE_UNDEFINED = 0,
> >
> > /* single-role peripheral, and dual-role default-b */
> > USB_STATE_B_IDLE,
> > USB_STATE_B_SRP_INIT,
> > USB_STATE_B_PERIPHERAL,
> >
> > /* single-role host, and dual-role default-a */
> > USB_STATE_A_IDLE,
> > USB_STATE_A_WAIT_VRISE,
> > USB_STATE_A_WAIT_BCON,
> > USB_STATE_A_HOST,
> > USB_STATE_A_SUSPEND,
> > USB_STATE_A_WAIT_VFALL,
> > USB_STATE_A_VBUS_ERR,
> >
> > #ifdef CONFIG_USB_OTG
> > /* extra dual-role default-b states */
> > USB_STATE_B_WAIT_ACON,
> > USB_STATE_B_HOST,
> > USB_STATE_A_PERIPHERAL,
> > #endif /* CONFIG_USB_OTG
> > };
> >
> > or something similar. Then we shouldn't allow anyone to access
> > phy->state directly, so we would need:
> >
> > static inline void usb_phy_set_state(struct usb_phy *phy,
> > enum usb_state state)
> > {
> > phy->state = state;
> > }
> >
> > static inline enum usb_state usb_phy_get_state(struct usb_phy *phy)
> > {
> > return phy->state;
> > }
> >
> Then, at later general OTG driver, we need to know struct usb_phy *phy,
> but how can we get it at OTG driver?
you could make otg point to its phy. That's simple to handle at any
time.
> I am a little confused by using phy->state to stand for usb_state that I think
> there is no relationship between usb_state with USB PHY.
well, there's no relationship between usb_state and OTG. The state isn't
OTG-specific, it's USB specific. This is a difficult detail to find the
proper owner, but I don't think we should tie the state to OTG, because
systems without OTG wouldn't be able to track their states too.
--
balbi
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