Hello Peter, On 16-03-29 00:24:46, Peter Chen wrote: > > > > > On 2016-03-25 00:40, Peter Chen wrote: > > > On Tue, Mar 15, 2016 at 02:08:26PM +0530, Sanchayan Maity wrote: > > >> Hello Peter, > > >> > > >> The existing usage of extcon in Chipidea driver relies on OTG > > >> registers. In case of SoC with dual role device but not a true OTG > > >> controller, this does not work. Such SoC's should specify the > > >> existing CI_HDRC_DUAL_ROLE_NOT_OTG flag and do the role switch > > >> without checking any of the OTG registers in my opinion. > > >> This is the case for Vybrid which uses a Chipidea IP but does not > > >> have a true 5 pin OTG implemented. > > > > > > Sorry to reply you late due to my new born baby. > > > > > > Are you sure Vybrid is NOT OTG core? Afaik, it is uses the same IP > > > base with other Freescale SoCs, just the IP core is 2.40a. > > > When working at device mode, can you read vbus status through OTGSC? > > > And if there is an ID pin (input pin) for Vybrid? I mean SoC, not the > > > board. > > > > I think the IP is actually OTG capable, the registers are there, but the signals > > seem not to be available on the SoC package. That is also what the RM says... > > > > Quotes from the RM: > > > > "OTG controller should be treated as > > Dual role controller that allows the > > controller to act as either a Host or a > > device with no support for HNP/SRP." > > > > And later, in Chapter 11.1: > > > > "The USB is not a true OTG. It can be configured by software to function either > > as peripheral or as host. The ID pin, which is unique for OTG operation, is not > > present in this implementation. There are no five pin interface. The user will > > get four pin host/ device interface." > > > > Get it, thanks. I am doing a patch for covering this case and vbus always-on case. If I may ask at this point, how would your implementation be covering this case for Vybrid? - Sanchayan. -- 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
