On Thu, Nov 14, 2024 at 11:59:41AM -0800, Amit Sunil Dhamne wrote:
> Hi Heikki,
>
> On 11/2/24 8:43 PM, Amit Sunil Dhamne wrote:
> > Add support for parsing DT time property "sink-bc12-completion-time-ms".
> > This timer is used to relax the PD state machine during Sink attach to
> > allow completion of Battery Charging (BC1.2) charger type detection in
> > TCPC before PD negotiations. BC1.2 detection is a hardware mechanism to
> > detect charger port type that is run by some controllers (such as
> > "maxim,max33359") in parallel to Type-C connection state machines.
> > This is to ensure that BC1.2 completes before PD is enabled as running
> > BC1.2 in parallel with PD negotiation results in delays violating timer
> > constraints in PD spec.
> >
> > This is an optional timer and will not add any delay unless explicitly
> > set.
> >
> > Signed-off-by: Amit Sunil Dhamne <amitsd@xxxxxxxxxx>
> > Reviewed-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> > ---
> > drivers/usb/typec/tcpm/tcpm.c | 16 +++++++++++++++-
> > 1 file changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > index b3d5d1d48937..8b325b93b5a9 100644
> > --- a/drivers/usb/typec/tcpm/tcpm.c
> > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > @@ -319,6 +319,7 @@ struct pd_timings {
> > u32 sink_wait_cap_time;
> > u32 ps_src_off_time;
> > u32 cc_debounce_time;
> > + u32 snk_bc12_cmpletion_time;
> > };
> > struct tcpm_port {
> > @@ -4978,7 +4979,16 @@ static void run_state_machine(struct tcpm_port *port)
> > if (ret < 0)
> > tcpm_set_state(port, SNK_UNATTACHED, 0);
> > else
> > - tcpm_set_state(port, SNK_STARTUP, 0);
> > + /*
> > + * For Type C port controllers that use Battery Charging
> > + * Detection (based on BCv1.2 spec) to detect USB
> > + * charger type, add a delay of "snk_bc12_cmpletion_time"
> > + * before transitioning to SNK_STARTUP to allow BC1.2
> > + * detection to complete before PD is eventually enabled
> > + * in later states.
> > + */
> > + tcpm_set_state(port, SNK_STARTUP,
> > + port->timings.snk_bc12_cmpletion_time);
> > break;
> > case SNK_STARTUP:
> > opmode = tcpm_get_pwr_opmode(port->polarity ?
> > @@ -7090,6 +7100,10 @@ static void tcpm_fw_get_timings(struct tcpm_port *port, struct fwnode_handle *fw
> > port->timings.cc_debounce_time = val;
> > else
> > port->timings.cc_debounce_time = PD_T_CC_DEBOUNCE;
> > +
> > + ret = fwnode_property_read_u32(fwnode, "sink-bc12-completion-time-ms", &val);
> > + if (!ret)
> > + port->timings.snk_bc12_cmpletion_time = val;
> > }
> > static int tcpm_fw_get_caps(struct tcpm_port *port, struct fwnode_handle *fwnode)
>
>
> I wanted to gently follow up with you on this patchset if this looks okay to
> you?
Sorry, this is okay by me. I thought that there's still some problem
with the device property itself, but I must have misunderstood.
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
--
heikki
