Hi, On Fri, Aug 10, 2012 at 06:32:36AM +0000, Chen Peter-B29397 wrote: > > > According to USB_OTG_and_EH_2-0-final_plus_errata_and_ecn_20110714 - > > final.pdf > > > Chapter7.1, 7,2. The states at enum usb_otg_state are all OTG state. > > > > > > If you think others (except for A_DEVICE and B_HOST) are not otg- > > specific states, > > > then what are they? > > > > granted, they were defined on the OTG spec, but if you think about them, > > every peripheral usb controller starts on B_IDLE state. > > > > The OTG spec also says that any device can start SRP and any host can > > reply to that, not only OTG-capable devices; which means that B_SRP_INIT > > also applies to any device. > > > > B_PERIPHERAL applies to any device which gets enumerated. > > > > B_WAIT_ACON also applies to any device; it's that small timeframe where > > your device is ready and just waits for host. > > > > A_IDLE it's when your host is fully initialized but has no > > devices attached to it. > > > > A_WAIT_VRISE and A_WAIT_VFALL is applicable to any hosts which can > > control their charge pumps. > > > > A_WAIT_BCON is applicable to any host > > > > A_HOST is the normal operation of a host when it enumerated a device > > > > A_SUSPEND applies to any host. It's when it drives bus suspend > > signalling on the bus > > > > A_VBUS_ERR is that state when you just caught overcurrent. > > > > 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;
}
--
balbi
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