knuxify
commented
3 years ago NOTE: This comment is obsolete. The things that were required to get clocks working were initializing the power manager and adding bus clock support.
For anyone who wants to take up fixing clocks:
- I verified that the values used in clock initialization are correct
- Some clocks also have bus clocks (at presumably the same address), but this type of clock is not implemented in the driver. However, in downstream these appear to be nearly identical in handling to peripheral clocks. Adding those clocks does not fix the issues, however. (EDIT: I only enabled these for SDIO, but forgot to enable sleep clocks as well; bsc/i2c clocks only have bus clocks, they're a better target) (EDIT 2: Added sleep and bus clocks as per the u-boot driver; still doesn't work. (Although initializing the sleep clocks as software clocks doesn't bring up any issues.))
- The mainline clock driver appears to work in the same way as the downstream driver (although they're implemented very differently).
- This leaves the Kona Power Island (PI) as the only other potential culprit. It's enabled with
CONFIG_KONA_PI_MGRand has files in arch/arm/plat-kona/pi_mgr.c and arch/arm/mach-java/pi_mgr.c on downstream. It appears to control the operating frequency (OPP) of certain components and keeps a list of enabled clocks for use with "DFS" (which does not stand for debug fs, but it's not explained what it means anywhere). There's a file in downstream calledDocumentation/Broadcom/Kona_PM_DFS_and_QOS_API.txtwhich appears to explain some of the API used. - Seems like there were some changes to the clocks, but just doing git revert doesn't work; this might take a little fiddling (edit: tested this somewhat, i don't think that's the issue)
- See also: clock drivers in the u-boot tree: https://github.com/u-boot/u-boot/tree/master/arch/arm/cpu/armv7/bcm235xx
TL;DR: mainline driver matches downstream, this is probably a power management issue or a bootloader issue
UPDATE: Seems like PI_MGR/dfs isn't just for clocks; I was able to find mentions of it in the UART driver (alongside some other bcm-specific fixes, enabled with the CONFIG_BRCM_UART_CHANGES kernel config (also of note are CONFIG_DW_UART_WA_JIRA_1744 and CONFIG_DW_BT_UART_CHANGES). Also, there's some mentions of a wakelock, so we might need to add support for that as well.
onny
santeri3700
CheetahPixie
k8ieone
StandaSK
ijiki16
This issue outlines the current mainlining progress in this repo.
(As a general note: the default branch in this repo will contain random commits that are simply made to save my work. Once the time comes to upstream my patches, I'll re-do them.)
For those interested in Broadcom Kona mainlining: I'm actively looking for developers to help out with the mainlining process, feel free to reply in this thread and make a pull request if you want to contribute! Just adding a DTS for your device and telling us about the status would be enough.
whatever it isit's very low-level debuging stuff, no clue if it would even work on a production device, and doubt it's of any use to usSee also: https://wiki.postmarketos.org/wiki/Samsung_Galaxy_Grand_Neo_(samsung-baffinlite)