How it evolved (v1 → v3)

v1: a single patch to add fuel gauge on the board DTS. Turns out it wasn’t able to apply to my other patches I sent upstream because I applied it on top of an older patch series. Whoops.
v2: got a lot of good feedback here. Used GSBI5 instead of bit banging (which downstream used). Rebased onto correct dependencies this time and made b4 happy. And finally sorted expressatt DTS to be in line with the formatting standard used in qcom (tho I wish there was an auto formatter)
v3: no more comments in this patch series so it seems good to go! Just some further formatting changes and to use interrupts-extended

Konrad and Dmitry really seemed to like how I tested this patch series, which was nice to hear :). What I did was I booted using the mainline kernel with the battery, got the capacity, put the battery into another expressatt that ran downstream Android, and see if the battery % matched. It seems to be really close!

One thing I have yet to do is see how it lasts over a long period of time. Upstream seems to drain a lot more battery than downstream, and I wonder how I can further optimize this. But that’s for after I get all the peripherals working in mainline first. I also wonder if the drift in reading will diverge further over a charge cycle. I mainly tested it about every 5%, but I wonder if upstream going to 100% to 0% would actually read as 0% in downstream.

It was nice that the fuel gauge driver was already upstreamed! The only required part was to convert the board file to a DTS, and AI is really good at doing just that. It cut down on my work significantly.

AI

AI again was super helpful in generating this patch series. Was able to quickly iterate and send this upstream :)

On the other hand, I tried to get it to generate this article, but it was so bad. It came up with a decent template, which I filled it out with my voice. I don’t think AI is there for writing articles to be honest. However, it’s really good at rephrasing things, so it might be useful for that.

Overall

Super excited with the progress I’m making! :) It actually feels like I’m getting somewhere with the few sparse minutes I have each day. A few minutes are all I need to test, get logs, and prompt the AI to continue iteration. Very excited to see what the future holds!

Pending Upstream Submissions I’ve slightly neglected

What’s Working

UART
USB
eMMC/SD card
vol up, vol down, home, and power button
touchscreen
weird initrd error has been conquered!
lk2nd
tsens
nfc
accelerometer
light sensor
touchkeys
vibrator
camera flash
battery fuel guage

What’s Left

This list will potentially grow later as I find more things

magnetometer (added but potentially wrong mount matrix)
proximity (added but for some reason it is a floating value)
vibrator (added but I need to figure out if I can vary the frequency. Currently works at either 0% or 100%)
display
gpu
speakers/microphone/headphone jack
cameras
wifi/bluetooth
modem/gps(from modem?)
charging
cpufreq