We use the SRYR (SRDY Reset) command to power off our system after we've completed charging. The sequence is 1. Issue SRDY command 2. Power off internal battery. However, there is a chance that the internal battery will be powered back on (by the user) while the charger cable is still plugged in. In this situation, since the TPS chip was still powered, it will still be in its input switch disabled state. Thus we want to re-enable the switch when we boot back up with the SRDY command. We find that this command always gets rejected though.
We have PP_EXT configured for input, and status register, power status, and pd status indicate that pd controller is in a sink role. Active contract pdo shows that we are in a 20V 5A sink contract. We've tried supplying 00b, 01b, and 011b as inputs to the SRDY command, but they all result in it being rejected.
Based on what the datasheet says, the behavior we're seeing does not make sense:
The SRDY Task shall be considered rejected if:
- PD Controller is not in a Sink role. -- We are in a sink role, confirmed in several registers
- SwitchSelect == 00b and more than one switch is configured for input (PP_*config == 1Xb). -- Only PP_EXT is configured for input
• SwitchSelect == 01b and no switch was previously disabled by SRYR and more than one switch is configured with PP_*config == 10b. -- PP_EXT was disabled by SRYR
• SwitchSelect == 10b or 11b and the specified switch is not configured for input. -- PP_EXT is configured for input
• The selected switch cannot be enabled for some reason (UVP/OVP or some other fault). -- no registers report any protections or faults
