[Tinkerphones] CI20 - was Re: New LetuxOS Kernels and some tricks and thoughts

H. Nikolaus Schaller hns at goldelico.com
Fri Jul 5 18:28:18 CEST 2019


Hi Paul,

> Am 05.07.2019 um 18:10 schrieb Paul Boddie <paul at boddie.org.uk>:
> 
> On Friday 14. June 2019 11.13.16 H. Nikolaus Schaller wrote:
>> 
>> And it should not be too difficult to find the relevant patches and
>> forward-port them to mainline or simply add the missing LED nodes to the
>> ci20.dts. I'll give it a try in the next days.
> 
> I looked into this with the 5.1.8 kernel. The following configuration settings 
> are required:
> 
> CONFIG_LEDS_CLASS=y
> CONFIG_LEDS_GPIO=y
> CONFIG_LEDS_TRIGGERS=y
> CONFIG_LEDS_TRIGGER_MTD=y
> CONFIG_LEDS_TRIGGER_CPU=y
> 
> With the device tree file, the following from 3.18 seems to be necessary under 
> the / node:
> 
>        leds {  
>                compatible = "gpio-leds";
>                led3 {  
>                        gpios = <&gpc 0 0>;
>                        linux,default-trigger = "cpu0";
>                };
>                led2 {  
>                        gpios = <&gpc 1 0>;
>                        linux,default-trigger = "cpu1";
>                };
>                led1 {
>                        gpios = <&gpc 2 0>;
>                        linux,default-trigger = "nand-disk";
>                };
>                led0 {
>                        gpios = <&gpc 3 0>;
>                        linux,default-trigger = "mmc0";
>                };
>        };
> 
> With this, I can get led3 (cpu0) and led0 (mmc0) working. Maybe led1 (nand-
> disk) works if the NAND flash is accessed, but I don't use it. The led0 
> assignment could have been done as follows:
> 
> sudo sh -c "echo 'mmc0' > /sys/class/leds/led0/trigger"

It seems that I have forgotten to announce that I have added similar patches in 5.2-rc5 a while
ago to get the LEDs blink - and (untested) Infrared support:

	http://git.goldelico.com/?p=letux-kernel.git;a=shortlog;h=refs/heads/letux/dt-ci20
	http://git.goldelico.com/?p=letux-kernel.git;a=shortlog;h=refs/heads/letux/mips_defconfig

I did not yet backport to letux-4.19.x or letux-5.1.x. It was too low prio on my to-do list
to get done.

So I too your mail as a reminder and just have prepared it and it will appear with the next
stable release build of LetuxOS kernels. You will get a letux-5.1.17 tree soon.

> 
> Another thing with 5.1.8 is that the second core in the CPU (cpu1) is not 
> active.

Oh really! I think there is no cpufreq-info driver for the jz4780 so I did not yet
notice.

> I don't know how that got broken: it's probably the usual breaking up 
> of functionality into morsels that upstream might like, with the rest getting 
> dumped over the side.

This is something to discuss on the mips-creator mailing list.

BR and thanks,
Nikolaus



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