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
