+ Tomek Klimek
>> > +
>> > +static inline void cdns3_role_stop(struct cdns3 *cdns)
>> > +{
>> > + enum cdns3_roles role = cdns->role;
>> > +
>> > + if (role == CDNS3_ROLE_END)
>>
>> WARN_ON(role >= CNDS3_ROLE_END) ?
>>
>> > + return;
>> > +
>> > + mutex_lock(&cdns->mutex);
>> > + cdns->roles[role]->stop(cdns);
>> > + cdns->role = CDNS3_ROLE_END;
>>
>> Why change the role here? You are just stopping the role not changing it.
>> I think cdns->role should remain unchanged, so we can call cdns3_role_start()
>> if required without error.
>>
>
>The current version of this IP has some issues to detect vbus status correctly,
>we have to force vbus status accordingly, so we need a status to indicate
>vbus disconnection, and add some code to let controller know vbus
>removal, in that case, the controller's state machine can be correct.
>So, we increase one role 'CDNS3_ROLE_END' to for this purpose.
Hi, Tomek do you have any comment for this.
We have in RTL whole OTG machine and we can read all states.
>From otg specification we have in otg_state such bits:
5:3 host_otg_state "Current state of the OTG Host FSM.
3'b000 : H_IDLE
3'b001 : H_VBUS_ON
3'b010 : H_VBUS_FAILED
3'b011 : H_OTG_HOST_MODE
3'b100 : H_HOST_MODE
3'b101 : H_SWITCH_TO_DEVICE
3'b110 : H_A_SUSPEND
3'b111 : H_WAIT_VBUS_FALL" RO 0x0
2:0 dev_otg_state "Current state of the OTG Device FSM.
3'b000 : DEV_IDLE
3'b001 : DEV_MODE
3'b010 : DEV_SRP
3'b011 : DEV_WAIT_VBUS_FALL
3'b100 : DEV_SWITCH_TO_HOST
3'b101 : DEV_WAIT_FOR_CONN"
>
>CDNS3_ROLE_GADGET: gadget mode and VBUS on
>CDNS3_ROLE_HOST: host mode and VBUS on
>CDNS3_ROLE_END: VBUS off, eg either host or device cable on the port.
>
>So, we may start role from CDNS3_ROLE_END at probe when nothing is connected,
>and need to set role as CDNS3_ROLE_END at ->stop for further handling at
>role switch routine.
>
>> > + mutex_unlock(&cdns->mutex);
>> > +}
>> > +
>> > +static enum cdns3_roles cdns3_get_role(struct cdns3 *cdns)
>> > +{
>> > + if (cdns->roles[CDNS3_ROLE_HOST] && cdns->roles[CDNS3_ROLE_GADGET]) {
>> > + //TODO: implements selecting device/host mode
>> > + return CDNS3_ROLE_HOST;
>> > + }
>> > + return cdns->roles[CDNS3_ROLE_HOST]
>> > + ? CDNS3_ROLE_HOST
>> > + : CDNS3_ROLE_GADGET;
Cheers
Pawel,
