[SOLVED W/PATCHES] Fan support for RK3399 rockpro64

[EDIT: PATCHES TO FIX THIS ARE BELOW]

Hello,

Just burned libreelec-rk3399.arm-9.0-nightly-20190201-974f4cb-rockpro64.img.gz

And it's perfect.

I just can't get my 2-pin PWM fan enabled.

ayufan's debian had a sys class object 'hwmon0' which I could echo '255' into and start the fan, but no such device tree object has been initialized in this build.

I don't have the appropriate cables to re-wire my fan from being a 2-pin molex fan header in order to stick it into the GPIO header.

Can someone add hwmon0 or any possible way to control PWM fan on the 2-pin fan header to the image?

I wouldn't even mind building my own image if I have to, but I need to be shown how that works, I guess.

Ok, I even setup the build system and compiled my own working image from scratch.

But I am having a really hard time getting a pwm-fan entry to work; I think I am not doing the syntax right.

Can someone provide a diff to rk3399-rockpro64.dts that sets up pwm-fan properly ?

I thought it would just be like:

    fan0: pwm-fan {
        compatible = "pwm-fan";
        cooling-min-state = <0>;
        cooling-max-state = <3>;
        #cooling-cells = <2>;
        pwms = <&pwm1 0 10000 0>;
        cooling-levels = <0 102 170 230>;
    };

But I get syntax errors while parsing the tree, when it tries to compile it to dtb.

Thanks for your help, I got it working.

Mainly I was missing: CONFIG_SENSORS_PWM_FAN=y

Then I also had to patch pwm-fan.c because it was unable to compile.

I downloaded the patched pwm-fan.c from this:

UPSTREAM: hwmon: pwm-fan: Use pwm_get_args() where appropriate · ayufan-rock64/linux-kernel@356102c · GitHub

Then I diff'd it against the one included with LibreELEC and made a .patch and that made it compile + work properly.

I will be making some patches to submit soon.

At full load, my system runs at 101 F / roughly 38.3 C

n i c e

Here are the necessary 4 things get pwm-fan for rk3399-rockpro64.

EDIT: You have to have already setup the build system per the wiki:

Compile [LibreELEC.wiki]

These edits are to be done to your build system (not from within LibreELEC).

(A)

1. nano ~/LibreELEC.tv/projects/Rockchip/devices/RK3399/linux/rockchip-4.4/linux.aarch64.conf
2. Add this line: CONFIG_SENSORS_PWM_FAN=y

(B)

Create file: ~/LibreELEC.tv/projects/Rockchip/patches/linux/rockchip-4.4/linux-8000-rockpro64-pwm-fan.patch

--- /dev/null
+++ b/drivers/hwmon/pwm-fan.c
@@ -40,15 +40,18 @@
 
 static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 {
+    struct pwm_args pargs;
     unsigned long duty;
     int ret = 0;
 
+    pwm_get_args(ctx->pwm, &pargs);
+
     mutex_lock(&ctx->lock);
     if (ctx->pwm_value == pwm)
         goto exit_set_pwm_err;
 
-    duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
-    ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
+    duty = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM);
+    ret = pwm_config(ctx->pwm, duty, pargs.period);
     if (ret)
         goto exit_set_pwm_err;
 
@@ -215,6 +218,7 @@
 {
     struct thermal_cooling_device *cdev;
     struct pwm_fan_ctx *ctx;
+    struct pwm_args pargs;
     struct device *hwmon;
     int duty_cycle;
     int ret;
@@ -233,11 +237,19 @@
 
     platform_set_drvdata(pdev, ctx);
 
+    /*
+     * FIXME: pwm_apply_args() should be removed when switching to the
+     * atomic PWM API.
+     */
+    pwm_apply_args(ctx->pwm);
+
     /* Set duty cycle to maximum allowed */
-    duty_cycle = ctx->pwm->period - 1;
+    pwm_get_args(ctx->pwm, &pargs);
+
+    duty_cycle = pargs.period - 1;
     ctx->pwm_value = MAX_PWM;
 
-    ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period);
+    ret = pwm_config(ctx->pwm, duty_cycle, pargs.period);
     if (ret) {
         dev_err(&pdev->dev, "Failed to configure PWM\n");
         return ret;
@@ -303,14 +315,16 @@
 static int pwm_fan_resume(struct device *dev)
 {
     struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
+    struct pwm_args pargs;
     unsigned long duty;
     int ret;
 
     if (ctx->pwm_value == 0)
         return 0;
 
-    duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
-    ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
+    pwm_get_args(ctx->pwm, &pargs);
+    duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
+    ret = pwm_config(ctx->pwm, duty, pargs.period);
     if (ret)
         return ret;
     return pwm_enable(ctx->pwm);

(C)

Create file: ~/LibreELEC.tv/projects/Rockchip/patches/linux/rockchip-4.4/linux-8001-rockpro64-fan0.patch

--- /dev/null
+++ b/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts
@@ -128,6 +128,16 @@
         };
     };
 
+    fan0: pwm-fan {
+        compatible = "pwm-fan";
+        status = "okay";
+        cooling-min-state = <0>;
+        cooling-max-state = <3>;
+        #cooling-cells = <2>;
+        pwms = <&pwm1 0 40000 0>;
+        cooling-levels = <0 128 192 255>;
+    };
+
     ir-receiver {
         compatible = "gpio-ir-receiver";
         gpios = <&gpio0 RK_PA6 GPIO_ACTIVE_LOW>;

(D)

Now you have to activate the fan.

I didn't use thermal maps in the DTS (do it yourself) or anything smart/automated, because I just wanted my fan running 100% of the time, so I do the following in LibreELEC's autostart.sh :

echo 255 > /sys/class/hwmon/hwmon0/pwm1

Could someone from the LE team push the pwm-fan.c fix upstream and enable pwm sensors by default in the kernel options going forward, etc ?

So sorry, I wasn't very clear.

The fixes have to be done to the build system outside of LibreELEC (not within LibreELEC), which you can setup by following the guide on the wiki:
Compile [LibreELEC.wiki]

Once you have "~/LibreELEC.tv" folder on your build system, then you will make the changes above.

Yes, building LibreELEC is an "intermediate" task.

It is not easy when you are still new to Linux.

I am new to GitHub, and new to contributing patches, so I don't know how to submit patches yet, but I will learn soon.

I will eventually try to submit the patch, but I need to clean it up and integrate it with LibreELEC's existing patches.

( I'm pretty sure that I have to integrate the DTS bits directly into http://LibreELEC.tv/projects/Rockchip/patches/linux/rockchip-4.4/linux-0005-dts.patch )

I'll update this thread with the results if I am able to get the patch submitted.

Oh, is it at a different branch now?

I was using 9.0-devel, now I see yours says 9.1-devel.

Either, build using:

Release 9.0.0: Merge pull request #3280 from MilhouseVH/le90_settings_pr120 · LibreELEC/LibreELEC.tv · GitHub

Or, someone has to look at pwm-fan.c vs the diff and see why it's not applying (maybe someone upstreamed the fix already and my patch is now redundant?)

It will be a while before I have a chance to rebuild my ELEC kit so I'm not going to be able to fix that patch myself yet.

Ok, I was able to get to it faster than I thought.

I cloned 9.1-dev, then added the two patch files, and it worked without any changes.

Perhaps your patch files contain extra characters or linefeed/carriage return symbols from when you copied it.

I have attached the patches as actual files.

But this board wouldn't let me keep the extension as .patch, so you probably should rename these to .patch

( I was able to build the entire image, but I can't test it at all yet. I presume it works, don't see why it wouldn't. )

linux-8000-pwm-fan.txt

linux-8001-dts-pwm.txt

Until the patch is upstreamed, you will have to make your own build system and add it.

Read all of this before beginning:

https://forum.libreelec.tv

1) Install Ubuntu 16.04.x (LTS) server

Do everything from here on out as non-root.

2) sudo apt update && sudo apt upgrade

3) sudo apt install gcc make git unzip wget xz-utils

4) Clone the LibreELEC github:

cd ~
git clone https://github.com/LibreELEC/LibreELEC.tv.git
cd ~/LibreELEC.tv

5) Build the whole system once, without my patches, to make sure your build system is working:

PROJECT=Rockchip DEVICE=RK3399 ARCH=arm UBOOT_SYSTEM=rockpro64 make image

6) Download and copy the two patch files into ~/LibreELEC.tv/projects/Rockchip/patches/linux/rockchip-4.4/

* linux-8000-pwm-fan.txt

* linux-8001-dts-pwm.txt

7) Build it again now that the patch files are in:

PROJECT=Rockchip DEVICE=RK3399 ARCH=arm UBOOT_SYSTEM=rockpro64 scripts/clean linux
PROJECT=Rockchip DEVICE=RK3399 ARCH=arm UBOOT_SYSTEM=rockpro64 make image