RSS Parrot

PMIC ADC and Thermals

https://mainlining.dev/2022/08/06/pmic-adc-and-thermals/

Published: August 6, 2022 18:33

In this short post, I’ll share what I learned setting up ADC (analog-digital converter, used for measuring temp and voltage) and Thermal Monitor (notify kernel when stuff gets hot). Setup From what I can gather this applies to QCom SoCs/PMICs, so keep that…

initfs Refresher

https://mainlining.dev/2022/07/25/initfs-refresher/

Published: July 25, 2022 13:59

In this short post I’ll cover some material about initfs, which could be helpful during (or, more likely, not knowing it will be detrimental to) early mainlining. Background Linux boot process bootloader starts linux kernel, passing along initfs* kernel…

Regulators (SPMI/SMD)

https://mainlining.dev/2021/08/29/regulators-spmi-smd/

Published: August 29, 2021 19:53

Overview Regulators are responsible for providing power to various components. It is the last essential piece of the puzzle for early mainlining, that will lay the groundwork for the rest of the port. NOTE: These instructions apply for SPMI/SMD regulators,…

UFS phy driver

https://mainlining.dev/2021/07/04/ufs-phy-driver/

Published: July 4, 2021 14:20

Overview UFS stands for Universal Flash Storage, and is a replacement (or enhancement) over SD protocol for storage. The hardware is present for 2-3 years in phones now but most likely lacks any actual storage attached, so it wasn’t really necessary to…

RPM power domains (rpmpd)

https://mainlining.dev/2021/06/28/rpm-power-domains-rpmpd/

Published: June 28, 2021 21:01

Overview On downstream power domains and regular regulators are somewhat mixed together (like this). On mainline, power domains go in one place and regulators in another, because it turns out, they are completely different beasts. I can’t really explain…

Add pinctrl driver

https://mainlining.dev/2021/06/17/add-pinctrl-driver/

Published: June 17, 2021 20:19

Overview If you have played with arduino or rpi you might have come across the concept of pins to get input from sensors or control stuff (like relays or motors). Modern SoCs have hundreds of those, and each needs to be configured appropriately so the…

Enable USB networking

https://mainlining.dev/2021/06/13/enable-usb-networking/

Published: June 13, 2021 17:00

Hello old friend Sorry for the big delay between posts. I got caught up with some other work. In fact I had most of the work done 3 months ago, and there were some finishing touches left, but when I resumed on my journey I figured I can’t even run the…

Booting mainline kernel

https://mainlining.dev/2021/03/02/booting-mainline-kernel/

Published: March 2, 2021 12:17

I really didn’t expect this to be so easy, that it will be covered in a single post, but it actually is, so here we go. Overview It turns out to boot linux on a device you don’t need much. To be more specific you need to specify the following DT nodes: cpu…

Running stock kernel on PostmarketOS

https://mainlining.dev/2021/03/01/running-stock-kernel-on-postmarketos/

Published: March 1, 2021 19:22

Why are we doing this? In last post we finished by testing our newly build stock kernel. We used stock Android userspace, which is not ideal, because when we start actual mainlining the userspace will be PostmarketOS, so it would be good if we had some…

Building stock kernel

https://mainlining.dev/2021/02/22/building-stock-kernel/

Published: February 22, 2021 20:07

The next step in mainlining is to build the original/stock/downstream kernel. We’ll use it as a reference point and to extract additional details when the need arises. The stock kernel’s source is provided by the manufacturer, so building it should be…