Hi James,
On 2/12/25 16:56, James A. MacInnes wrote:
On Wed, 12 Feb 2025 15:29:54 +0000
Caleb Connolly <caleb.connolly@xxxxxxxxxx> wrote:
Hi Caleb,
Hi James,
On 2/12/25 01:07, James A. MacInnes wrote:
This patch extends the Qualcomm USB VBUS regulator driver to support
PMI8998 PMIC alongside the existing support for PM8150B.
Thanks for the patch!
Happy to try and contribute. I know that the working Type-C port is
going to be a misery after the relative simplicity of pushing the VBUS
upstream.
Yeah, it's hard to get used to the process... I'm happy to hear you're
trying to get type-c working on this platform though! This will make a
bunch of folks very happy if it finally lands, folks have been doing all
sorts of workarounds for this over on
https://wiki.postmarketos.org/wiki/OnePlus_6_(oneplus-enchilada)#OTG_doesn't_work
Key changes:
- Added current limit tables specific to PMI8998.
I also played around with vbus on PMI8998 before for type-c support
(unfortunately didn't make it's way to the lists yet...) and I needed
some additional changes for this to work correctly. I found that it
was possible for the overcurrent protection to be hit if the type-c
port manager allowed the peripheral to pull current too early, and
it's necessary to allow 2.5ms enable time.
PM8150b doesn't have these limitations (and supports the instant
power role switch feature that's part of the type-c PD spec, allowing
the power role to be switched without either side losing power e.g.
when you unplug the power supply from a dock), hence it's only
necessary for PMI8998.
I would suggest implementing a proper .is_enabled op to poll the
status register for OTG_STATE_ENABLED and configuring
qcom_usb_vbus_rdesc.enable_time = 250000;
Kind regards,
Technical question for you in regards to the VBUS overcurrent and
timing for the PMI8998. I would like to try and reproduce what you have
seen as my system hasn't had switching issues, but then again the TCPM
system may be covering the exact bug you are mentioning. I also
searched for some definite bit in the 4.9 Android driver and was left
wanting. As of yet, I have not had issues with the overcurrent
protecction.
I guess there could be differences in our implementations, there is a
delay after enabling the regulator for pm8150b type-c iirc
I never got around to chasing some of the remaining issues and sending
this upstream, but maybe my patches will be useful for you:
https://git.codelinaro.org/caleb_connolly/kernel/-/commits/b4/pmi8998-typec/?ref_type=heads
I spent many many hours pouring over the smb2 driver downstream, so feel
free to reach out if you have some specific questions.
I will be all too happy to migrate to the PM8150B and its associated
SoCs and leave the 845 platform to history.
Well I for one am always happy to see SDM845 getting attention, it has a
special place in my heart :>
And still gets love over here, even if not nearly enough of these
patches have made it upstream:
https://gitlab.com/sdm845-mainline/linux/-/commits/sdm845/6.13-release?ref_type=heads
Kind regards,
Thank you for your feedback and I look forward to narrowing down this
issue.
Best wishes,
--
Caleb (they/them)
