[Letux-kernel] X1600 / LX16 support - here: adding MMC

[H. Nikolaus Schaller]

> Am 10.02.2024 um 12:45 schrieb Andreas Kemnade <andreas at kemnade.info>:
> 
> On Sat, 10 Feb 2024 11:40:52 +0100
> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
>> 
>> Can you see /sys/class/leds? Then it should be possible to manually control
>> the heartbeat LED gpio.
>> 
> / # date ; sleep 60 ; date
> Thu Jan  1 12:57:29 UTC 1970
> Thu Jan  1 12:58:29 UTC 1970
> / # 
> / # cd /sys/class/leds/led-0/
> device/     power/      subsystem/
> / # cd /sys/class/leds/led-0/
> /sys/devices/platform/leds/leds/led-0 # ls
> brightness      max_brightness  subsystem       uevent
> device          power           trigger
> /sys/devices/platform/leds/leds/led-0 # cat brightness 
> 0
> /sys/devices/platform/leds/leds/led-0 # cat trigger 
> [none] rfkill-any rfkill-none kbd-scrolllock kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock kbd-ctrllock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock kbd-ctrlrlock timer oneshot heartbeat cpu cpu0 default-on transient mmc0
> /sys/devices/platform/leds/leds/led-0 # echo 1 >brightness 
> /sys/devices/platform/leds/leds/led-0 # echo 0 >brightness 
> /sys/devices/platform/leds/leds/led-0 # cat max_brightness 
> 1
> /sys/devices/platform/leds/leds/led-0 # 
> 
> no effect, the middle led is constantly on, the others are
> constantly off.
> /sys/devices/platform/leds/leds/led-0 # echo heartbeat >trigger 
> 
> no effect either.

I think that's a hot lead!

If pinctrl is broken, this can explain other problems. Like no clock at msc1.
Or why we have to disable the UART DTS nodes. In that case the U-Boot defaults likely survive.

Despite the pinctrl driver being part of the working 5.10.y it has got some (un)tested
upstream work and adaptations for v6.8.

Some ideas:
* check /sys/kernel/debug/gpio (if the gpio is configured as output)
* add printk to ingenic-pinctrl driver
* read out the pinctrl registers with devmem and compare to 5.10.y kernel

BR,
Nikolaus