[PATCH v10 6/6] usb: typec: tcpm/tcpci_maxim: deprecate WAR for setting charger mode
Amit Sunil Dhamne
amitsd at google.com
Thu Apr 2 11:47:30 PDT 2026
Hi Heikki,
On 4/2/26 7:33 AM, Heikki Krogerus wrote:
> Hi Amit,
>
>> +static int get_vbus_regulator_handle(struct max_tcpci_chip *chip)
>> +{
>> + if (IS_ERR_OR_NULL(chip->vbus_reg)) {
>> + chip->vbus_reg = devm_regulator_get_exclusive(chip->dev,
>> + "vbus");
> Sorry to go back to this, but why can't you just get the regulator in
> max_tcpci_probe()?
Thanks for calling this out. This was an intentional design decision to
break a circular dependency.
The charger driver is guaranteed to probe after the TCPC driver due to a
power supply dependency (the TCPC is a supplier of power for the Battery
Charger). However, the charger driver is also the regulator provider for
VBUS out (when Type-C goes into source mode).
Because of this, the regulator handle will not be available during the
TCPC driver's probe. If we tried to fetch it in max_tcpci_probe() and
returned -EPROBE_DEFER, it would create a probe deadlock, as the charger
would then never probe. Therefore, I made the decision to get the
regulator handle lazily and on-demand.
Thanks,
Amit
>
> thanks,
>
>> + if (IS_ERR_OR_NULL(chip->vbus_reg)) {
>> + dev_err(chip->dev,
>> + "Failed to get vbus regulator handle\n");
>> + return -ENODEV;
>> + }
>> + }
>> +
>> + return 0;
>> +}
More information about the linux-arm-kernel
mailing list