Spectrum SBE1V1K (IPQ9574) OpenWrt Support

For Developers
41

I saw them, haven’t tested yet. Right now, setting the period and duty cycle very high (like 4000000) will run the fan full speed. But it shouldn’t need to be set that high.

42

With your latest changes my fan does spin for second fairly weakly with the router at idle

43

Testing this is how I fried my unit (12v fan to tach port, aka cpu’s pwm controller and thus, cpu), so I’ll defer to someone else who has a better idea.

44

Thanks! I sent up a new PR.

45

There is potentially a hardware limitation or a driver issue with PWM as I set the period to 1000000ns(1000hz) in the dts and the fan spins at the lowest duty cycle fine(I raised it to 50%). At 10khz it spun weakly when trying to run at 50% but would run constantly when commanded.

46

probably a stupid question, we need kernel 6.18 (which appears to be the next LTS) for qualcommbe, right ?

47

There’s a PR for it already qualcommbe: support 6.18 kernel #21506

48

I've found that one, but there's also one for 6.12 testing kernel.

49

The devices I was working on ran great on 6.12 with the mentioned depends.

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50

I’m half convinced it’s a driver issue. The guy porting it upstream says he only has IPQ5018 and IPQ6010(?) devices, not IPQ9574.

Source: https://patchwork.ozlabs.org/project/linux-pwm/patch/20260204-ipq-pwm-v20-2-91733011a3d1@outlook.com/

51

I tested 2 more PWM periods and the usable limit for the current driver is somewhere between 2.5khz(worked but noisy) and 5khz(similar result as 10khz). Someone with an oscilloscope will have to verify that the driver is actually generating the right frequency even.

52

The guy working on the PWM drivers is updating old patches released by Qualcomm with zero hardware documentation so working around the issue by lowering the pwm period is likely the best we can do for now.

53

I can’t find the datasheet for the fan inside the router, a Delta ASB0512HA, but I did find that Delta does make fans(Delta THA series) with a preferred pwm clock of 1khz and this fan did like running at 1khz. The data sheets on similar delta fans usually spec a minimum duty cycle to start from a stop at 30%.

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54

So I had forgotten that I found a unit on eBay a few weeks ago… the seller took forever to ship it. It arrived yesterday… we resume! MAC addresses should be set correctly now.

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55

http://scpfirmware.tau.spectrum.net/SCP_1.0.5-1-499855-g202411181854-SBE1V1K-prod.simg

If you want to look through vendor fw

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