On Fri, Sep 18, 2020 at 7:20 AM Heikki Krogerus
<heikki.krogerus@xxxxxxxxxxxxxxx> wrote:
>
> On Thu, Sep 17, 2020 at 03:18:56AM -0700, Badhri Jagan Sridharan wrote:
> > Programs VBUS_SINK_DISCONNECT_THRESHOLD based on the power_role,
> > voltage requested as sink, mode of operation.
> >
> > The programmed threshold is based on vSinkDisconnect and
> > vSinkDisconnectPD values.
> >
> > Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> > ---
> > Changes since v1:
> > - Changing patch version to v6 to fix version number confusion.
> >
> > Changes since v6:
> > - Rebase on usb-next.
> > ---
> > drivers/usb/typec/tcpm/tcpci_maxim.c | 48 ++++++++++++++++++++++++++++
> > 1 file changed, 48 insertions(+)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim.c
> > index 723d7dd38f75..8289b596d2ee 100644
> > --- a/drivers/usb/typec/tcpm/tcpci_maxim.c
> > +++ b/drivers/usb/typec/tcpm/tcpci_maxim.c
> > @@ -137,6 +137,52 @@ static void max_tcpci_init_regs(struct max_tcpci_chip *chip)
> > return;
> > }
> >
> > +static int max_tcpci_set_auto_vbus_discharge_threshold(struct tcpci *tcpci, struct tcpci_data *data,
> > + enum typec_role port_role,
> > + enum typec_pwr_opmode mode, bool pps_active,
> > + u32 requested_vbus_voltage_mv)
> > +{
> > + struct max_tcpci_chip *chip = tdata_to_max_tcpci(data);
> > + u32 threshold = 0;
> > + u8 pwr_ctrl;
> > +
> > + /*
> > + * Indicates that vbus is going to go away due PR_SWAP, hard reset etc.
> > + * Do not discharge vbus here.
> > + */
> > + if (requested_vbus_voltage_mv == 0)
> > + goto write_thresh;
>
> I would assume that step is the same for every TCPC, no?
I agree so moved to tcpci.c code.
>
> > + if (port_role == TYPEC_SINK) {
> > + max_tcpci_read8(chip, TCPC_POWER_CTRL, &pwr_ctrl);
> > + if (pwr_ctrl & TCPC_FAST_ROLE_SWAP_EN) {
> > + /* To prevent disconnect when the source is fast role swap is capable. */
> > + threshold = 3500;
> > + } else if (mode == TYPEC_PWR_MODE_PD) {
> > + if (pps_active)
> > + threshold = (95 * requested_vbus_voltage_mv / 100) - 850;
> > + else
> > + threshold = (95 * requested_vbus_voltage_mv / 100) - 1250;
> > + } else {
> > + /* 3.5V for non-pd sink */
> > + threshold = 3500;
> > + }
> > + } else {
> > + /* 4V for source */
> > + threshold = 4000;
> > + }
> > +
> > + threshold = threshold / TCPC_VBUS_SINK_DISCONNECT_THRESH_LSB;
> > +
> > + if (threshold > TCPC_VBUS_SINK_DISCONNECT_THRESH_MAX) {
> > + dev_err(chip->dev, "VBUS_SINK_DISCONNECT_THRESH out of range");
> > + return -EINVAL;
> > + }
> > +
> > +write_thresh:
> > + return max_tcpci_write16(chip, TCPC_VBUS_SINK_DISCONNECT_THRESH, threshold);
>
> So couldn't tcpci.c write that register? This callback would then just
> calculate the value. I just want to avoid boilerplate.
Done !
>
> The threshold has type u32, but you still pass it to
> max_tcpci_write16(). Is that on purpose (doesn't the compiler
> complain)?
I didnt see any warnings ! I don't know why.
It wouldn't overflow though as TCPC_VBUS_SINK_DISCONNECT_THRESH_MAX
has a max value of 0x3ff. Have corrected it though and moved the code
to tcpci.c in v8.
Thanks,
Badhri
>
> thanks,
>
> --
> heikki
