On Tue, Apr 14, 2015 at 01:41:48PM +0300, Roger Quadros wrote: > struct otg_fsm is the interface to the OTG state machine. > > Document the input, output and internal state variables. > Definations are taken from Table 7-2 and Table 7-4 of > the USB OTG & EH Specification Rev.2.0 > > Re-arrange some of the members as per use case for more > clarity. > > Signed-off-by: Roger Quadros <rogerq@xxxxxx> > --- > include/linux/usb/otg-fsm.h | 80 +++++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 73 insertions(+), 7 deletions(-) > > diff --git a/include/linux/usb/otg-fsm.h b/include/linux/usb/otg-fsm.h > index b6ba1bf..c5b74c5 100644 > --- a/include/linux/usb/otg-fsm.h > +++ b/include/linux/usb/otg-fsm.h > @@ -57,37 +57,103 @@ enum otg_fsm_timer { > NUM_OTG_FSM_TIMERS, > }; > > -/* OTG state machine according to the OTG spec */ > +/** > + * struct otg_fsm - OTG state machine according to the OTG spec > + * > + * OTG hardware Inputs > + * > + * Common inputs for A and B device What's the intention you leave two spaces at above line? > + * @id: TRUE for B-device, FALSE for A-device. > + * @adp_change: TRUE when current ADP measurement (n) value, compared to the > + * ADP measurement taken at n-2, differs by more than CADP_THR > + * @power_up: TRUE when the OTG device first powers up its USB system and > + * ADP measurement taken if ADP capable > + * > + * A-Device state inputs > + * @a_srp_det: TRUE if the A-device detects SRP > + * @a_vbus_vld: TRUE when VBUS voltage is in regulation > + * @b_conn: TRUE if the A-device detects connection from the B-device > + * @a_bus_resume: TRUE when the B-device detects that the A-device is signaling > + * a resume (K state) > + * B-Device state inputs > + * @a_bus_suspend: TRUE when the B-device detects that the A-device has put the bus into suspend > + * @a_conn: TRUE if the B-device detects a connection from the A-device > + * @b_se0_srp: TRUE when the line has been at SE0 for more than the minimum > + * time before generating SRP > + * @b_ssend_srp: TRUE when the VBUS has been below VOTG_SESS_VLD for more than > + * the minimum time before generating SRP > + * @b_sess_vld: TRUE when the B-device detects that the voltage on VBUS is > + * above VOTG_SESS_VLD > + * @test_device: TRUE when the B-device switches to B-Host and detects an OTG test device > + * FIXME: must be set by host/hub driver Yes, according to pid/vid pair. > + * > + * Application inputs (A-Device) > + * @a_bus_drop: TRUE when A-device application needs to power down the bus > + * @a_bus_req: TRUE when A-device application wants to use the bus. > + * FALSE to suspend the bus > + * > + * Application inputs (B-Device) > + * @b_bus_req: TRUE during the time that the Application running on the > + * B-device wants to use the bus > + * > + * Auxilary inputs > + * @a_sess_vld: ?? See OTG spec 1.3, and obsolete now. > + * @b_bus_suspend: ?? > + * @b_bus_resume: ?? They are used at current otg fsm, just for B-host. > + * > + * OTG Output status. Read only for users. updated by otg_ops() helpers > + * > + * Outputs for Both A and B device > + * @drv_vbus: TRUE when A-device is driving VBUS > + * @loc_conn: TRUE when the local device has signaled that it is connected to the bus > + * @loc_sof: TRUE when the local device is generating activity on the bus > + * @adp_prb: TRUE when the local device is in the process of doing ADP probing > + * > + * Outputs for B-device state > + * @adp_sns: TRUE when the B-device is in the process of carrying out ADP sensing > + * @data_pulse: TRUE when the B-device is performing data line pulsing > + * > + * Internal Variables > + * > + * a_set_b_hnp_en: TRUE when the A-device has successfully set the b_hnp_enable bit in the B-device. > + * FIXME: OTG fsm uses otg->host->b_hnp_enable instead a_set_b_hnp_en is for otg 2.0 and it should instead of otg->host->b_hnp_enable at otg fsm. > + * b_srp_done: TRUE when the B-device has completed initiating SRP > + * b_hnp_enable: TRUE when the B-device has accepted the SetFeature(b_hnp_enable) B-device > + * FIXME: OTG fsm uses otg->gadget->b_hnp_enable instead Yes > + * a_clr_err: Asserted (by application ?) to clear a_vbus_err due to an overcurrent condition > + * and causes the A-device to transition to a_wait_vfall > + */ > struct otg_fsm { > /* Input */ > int id; > int adp_change; > int power_up; > - int test_device; > - int a_bus_drop; > - int a_bus_req; > int a_srp_det; > int a_vbus_vld; > int b_conn; > int a_bus_resume; > int a_bus_suspend; > int a_conn; > - int b_bus_req; > int b_se0_srp; > int b_ssend_srp; > int b_sess_vld; > + int test_device; > + int a_bus_drop; > + int a_bus_req; > + int b_bus_req; > + > /* Auxilary inputs */ > int a_sess_vld; > int b_bus_resume; > int b_bus_suspend; > > /* Output */ > - int data_pulse; > int drv_vbus; > int loc_conn; > int loc_sof; > int adp_prb; > int adp_sns; > + int data_pulse; > > /* Internal variables */ > int a_set_b_hnp_en; > @@ -95,7 +161,7 @@ struct otg_fsm { > int b_hnp_enable; > int a_clr_err; > > - /* Informative variables */ > + /* Informative variables. All unused as of now */ > int a_bus_drop_inf; > int a_bus_req_inf; > int a_clr_err_inf; > -- > 2.1.0 > -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html