Re: [PATCH] regulator: qcom-rpmh: Fix pm8010 pmic5_pldo502ln minimum voltage

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 19/02/2024 3:06 a.m., Fenglin Wu wrote:


On 2024/2/15 6:47, Bryan O'Donoghue wrote:
On 14/02/2024 14:52, Mark Brown wrote:
On Wed, Feb 14, 2024 at 02:44:56PM +0000, Bryan O'Donoghue wrote:
On 14/02/2024 14:13, Mark Brown wrote:

Not just that but also note that every voltage step in the range will
have the 8mV offset added.

The documents I have just show sensors attached to ldo3, ldo4 and ldo6 fixed
at 1.808.

I don't think there's any better or different information than a +200000uV
increment TBH.

This seems like a very surprising and unusual hardware design, the
1.808V voltage is already unusual.  Note that this may break systems
that are trying to set a range of say 1.8-2.0V if they actually need to
set 2V.

Hmm. I'm sure the rail value should be 1.808 its all over the documentation for example when we get to index 3 we hit 2608000

REGULATOR_LINEAR_RANGE(1808000, 0,  2,  200000),
1808000 0
2008000 1
2208000 2
2408000 x
REGULATOR_LINEAR_RANGE(2608000, 3,  28, 16000),

And there are other rails @ 1v8 if 1v8

The one thing I can't easily verify is index 0 = 1808000 and not say 1800000 or indeed that the increment is 200000 and not say 8000.

I'll see if I can ask around with the hw people and get a more complete answer.

Similarly now that you've gotten me digging into this problem, it's not clear to me why this regulator isn't just a linear regulator with an 8mv increment over a range of indexes.

At least the documentation I'm looking at doesn't elucidate.

I'll dig some more.
Please see the voltage steps for LDO3/4/6 described in the PM8010 TDOS document which is the most authoritative that we used internally for PMIC driver development:

I will look - however

1. The powertree internal docs for xe801000 show 1.808 rails derived
   from 1.856 rails for camera sensors

2. Publicly available with registration : 80-185821-1

https://docs.qualcomm.com/bundle/80-18582-1/resource/80-18582-1_REV_AV_PM8010_Data_Sheet.pdf

   Table 3-7 Linear/low-voltage regulator summary

   Specified programmable range (V)
   ldo3, ldo4, ldo6 = 1.808 to 3.312

3. The pmic ranges I'm looking at on the internal
   show increases of 8000 mv linearly

And I do see from the document change history that step 0 was changed from 1808mV and step 2 was changed from 2512mV, I don't know the reason of the change though.

Hrmm...

OK, that's enough to investigate further.

---
bod





[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux