| Message ID | 20181008125359.2D56E3FB79@swsrvapps-01.diasemi.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] usb: typec: tcpm: Report back negotiated PPS voltage and current | expand |
On 10/08/2018 05:53 AM, Adam Thomson wrote: > Currently when requesting a specific voltage or current through > the psy interface, for PPS, when reading back from that interface > the values will always be the same as previously given, if the > request was successful. However PPS only allows for 20mV voltage > steps and 50mA current steps, and the psy class expects microvolt > and micro amp requests, so inbetween values can be provided through > this interface. Really when reading back the true values negotiated > should be given, and not the ones originally asked for. > > To report the actual values negotiated with the Source, the values > stored are now rounded down to the relevant step units prior to > building the PPS request, so that those values are later correctly > reported through the psy interface. In addition this improves the > adjustments made to meet the operating power requirements of the > platform, which previously could have been slightly out due to not > using valid PPS units of voltage and current. > > Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > Changes are based on usb-testing (e7a2c3fa2857) > > Changes in v2: > - Rounding down of PPS voltage and current values moved to relevant API > functions so stored values are correctly updated prior to all subsequent > usage and decision making, as discuessed with Guenter. > > drivers/usb/typec/tcpm/tcpm.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > index b06eac8..dbbd71f 100644 > --- a/drivers/usb/typec/tcpm/tcpm.c > +++ b/drivers/usb/typec/tcpm/tcpm.c > @@ -4113,6 +4113,9 @@ static int tcpm_pps_set_op_curr(struct tcpm_port *port, u16 op_curr) > goto port_unlock; > } > > + /* Round down operating current to align with PPS valid steps */ > + op_curr = op_curr - (op_curr % RDO_PROG_CURR_MA_STEP); > + > reinit_completion(&port->pps_complete); > port->pps_data.op_curr = op_curr; > port->pps_status = 0; > @@ -4166,6 +4169,9 @@ static int tcpm_pps_set_out_volt(struct tcpm_port *port, u16 out_volt) > goto port_unlock; > } > > + /* Round down output voltage to align with PPS valid steps */ > + out_volt = out_volt - (out_volt % RDO_PROG_VOLT_MV_STEP); > + > reinit_completion(&port->pps_complete); > port->pps_data.out_volt = out_volt; > port->pps_status = 0; >
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index b06eac8..dbbd71f 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -4113,6 +4113,9 @@ static int tcpm_pps_set_op_curr(struct tcpm_port *port, u16 op_curr) goto port_unlock; } + /* Round down operating current to align with PPS valid steps */ + op_curr = op_curr - (op_curr % RDO_PROG_CURR_MA_STEP); + reinit_completion(&port->pps_complete); port->pps_data.op_curr = op_curr; port->pps_status = 0; @@ -4166,6 +4169,9 @@ static int tcpm_pps_set_out_volt(struct tcpm_port *port, u16 out_volt) goto port_unlock; } + /* Round down output voltage to align with PPS valid steps */ + out_volt = out_volt - (out_volt % RDO_PROG_VOLT_MV_STEP); + reinit_completion(&port->pps_complete); port->pps_data.out_volt = out_volt; port->pps_status = 0;
Currently when requesting a specific voltage or current through the psy interface, for PPS, when reading back from that interface the values will always be the same as previously given, if the request was successful. However PPS only allows for 20mV voltage steps and 50mA current steps, and the psy class expects microvolt and micro amp requests, so inbetween values can be provided through this interface. Really when reading back the true values negotiated should be given, and not the ones originally asked for. To report the actual values negotiated with the Source, the values stored are now rounded down to the relevant step units prior to building the PPS request, so that those values are later correctly reported through the psy interface. In addition this improves the adjustments made to meet the operating power requirements of the platform, which previously could have been slightly out due to not using valid PPS units of voltage and current. Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com> --- Changes are based on usb-testing (e7a2c3fa2857) Changes in v2: - Rounding down of PPS voltage and current values moved to relevant API functions so stored values are correctly updated prior to all subsequent usage and decision making, as discuessed with Guenter. drivers/usb/typec/tcpm/tcpm.c | 6 ++++++ 1 file changed, 6 insertions(+)