lkml.org 
[lkml]   [2018]   [Nov]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/8] BCM2835 PM driver
Hi Eric,

> Eric Anholt <eric@anholt.net> hat am 20. November 2018 um 18:19 geschrieben:
>
>
> This series moves the BCM2835 WDT driver that controls a fraction of
> the PM block out to soc/ and adds most of the rest of its
> functionality. My motivation has been to have V3D be functional
> without firmware calls, probably improve its interactivity (since
> we'll be able to power on/off without RPC to the firmware that may be
> busy with other tasks), and (in a patch not submitted in this series)
> extend its binding to use the reset controller instead of trying to
> reset by toggling its power domain.
>
> I've tested V3D with a few hours of running a V3D test, sleep(1) (to
> trigger PM domain off); running a GPU hang job (to trigger reset);
> sleep(1). The non-hanging success-case job always passed, and dmesg
> had no complaints from bcm2835-pm. The other power domains are not
> tested, but I've done my best.
>
> This series will probably also be of interest to the
> https://github.com/christinaa/rpi-open-firmware project for enabling USB.
>

apologize to give you my feedback after you send out the series.

I know you won't be happy about it, but i think we need a little more complex but future proof solution for this power driver. According to the register definition of the PM block, we have multiple functions here (power domains, watchdog, pads/pinctrl, ...). Since this is common for ARM SoCs there is a subsystem called mfd (multi function device) [1] to abstract all resources of the IP block.

This has the advantage that we don't need a monolithic driver which takes care of all functions.

According to this approach we would have the following drivers:
mfd/bcm2835.c
soc/bcm/bcm2835-power.c
watchdog/bcm2835_wdt.c

Best regards
Stefan

[1] - http://events17.linuxfoundation.org/sites/events/files/slides/belloni-mfd-regmap-syscon_0.pdf

\
 
 \ /
  Last update: 2018-11-20 18:50    [W:0.077 / U:0.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site