[v2] dt-bindings: hwmon: tda38640: Add interrupt & regulator properties

  Add properties for interrupt & regulator.
Also update example.

Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>

---
Changes in v2:
1. Remove TEST=..
2. Update regulator subnode property as vout0
3. Restore commented line in example
4. blank line after interrupts property in example.
---
 .../hwmon/pmbus/infineon,tda38640.yaml        | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)


base-commit: 7e90b5c295ec1e47c8ad865429f046970c549a66
  

On Wed, Feb 14, 2024 at 02:55:03PM +0530, Naresh Solanki wrote:
> Add properties for interrupt & regulator.
> Also update example.

I feel like a broken record. Your patches need to explain _why_ you're
doing what you're doing. I can read the diff and see this, but I do not
know what the justification for it is.

/30 seconds later
I really am a broken record, to quote from v1:
| Feeling like a broken record, given I am leaving the same comments on
| multiple patches. The commit message needs to explain why you're doing
| something. I can read the diff and see what you did!

https://lore.kernel.org/all/20240126-fleshed-subdued-36bae813e2ba@spud/

The patch itself does look better than the v1, with one minor comment
below.

Thanks,
Conor.

> Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
> 
> ---
> Changes in v2:
> 1. Remove TEST=..
> 2. Update regulator subnode property as vout0
> 3. Restore commented line in example
> 4. blank line after interrupts property in example.
> ---
>  .../hwmon/pmbus/infineon,tda38640.yaml        | 28 +++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
> index ded1c115764b..a93b3f86ee87 100644
> --- a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
> +++ b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
> @@ -30,6 +30,23 @@ properties:
>        unconnected(has internal pull-down).
>      type: boolean
>  
> +  interrupts:
> +    maxItems: 1
> +
> +  regulators:
> +    type: object
> +    description:
> +      list of regulators provided by this controller.
> +
> +    properties:
> +      vout0:

Why "vout0" if there's only one output? Is it called that in the
documentation? I had a quick check but only saw it called "vout".
Are there other related devices that would have multiple regulators
that might end up sharing the binding?

Thanks,
Conor.

> +        $ref: /schemas/regulator/regulator.yaml#
> +        type: object
> +
> +        unevaluatedProperties: false
> +
> +    additionalProperties: false
> +
>  required:
>    - compatible
>    - reg
> @@ -38,6 +55,7 @@ additionalProperties: false
>  
>  examples:
>    - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
>      i2c {
>          #address-cells = <1>;
>          #size-cells = <0>;
> @@ -45,5 +63,15 @@ examples:
>          tda38640@40 {
>              compatible = "infineon,tda38640";
>              reg = <0x40>;
> +
> +            interrupt-parent = <&smb_pex_cpu0_event>;
> +            interrupts = <10 IRQ_TYPE_LEVEL_LOW>;
> +
> +            regulators {
> +                pvnn_main_cpu0: vout0 {
> +                    regulator-name = "pvnn_main_cpu0";
> +                    regulator-enable-ramp-delay = <200>;
> +                };
> +            };
>          };
>      };
> 
> base-commit: 7e90b5c295ec1e47c8ad865429f046970c549a66
> -- 
> 2.42.0
>
  

On 2/14/24 09:51, Conor Dooley wrote:
> On Wed, Feb 14, 2024 at 02:55:03PM +0530, Naresh Solanki wrote:
>> Add properties for interrupt & regulator.
>> Also update example.
> 
> I feel like a broken record. Your patches need to explain _why_ you're
> doing what you're doing. I can read the diff and see this, but I do not
> know what the justification for it is.
> 
> /30 seconds later
> I really am a broken record, to quote from v1:
> | Feeling like a broken record, given I am leaving the same comments on
> | multiple patches. The commit message needs to explain why you're doing
> | something. I can read the diff and see what you did!
> 
> https://lore.kernel.org/all/20240126-fleshed-subdued-36bae813e2ba@spud/
> 
> The patch itself does look better than the v1, with one minor comment
> below.
> 
> Thanks,
> Conor.
> 
>> Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
>>
>> ---
>> Changes in v2:
>> 1. Remove TEST=..
>> 2. Update regulator subnode property as vout0
>> 3. Restore commented line in example
>> 4. blank line after interrupts property in example.
>> ---
>>   .../hwmon/pmbus/infineon,tda38640.yaml        | 28 +++++++++++++++++++
>>   1 file changed, 28 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
>> index ded1c115764b..a93b3f86ee87 100644
>> --- a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
>> +++ b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
>> @@ -30,6 +30,23 @@ properties:
>>         unconnected(has internal pull-down).
>>       type: boolean
>>   
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  regulators:
>> +    type: object
>> +    description:
>> +      list of regulators provided by this controller.
>> +
>> +    properties:
>> +      vout0:
> 
> Why "vout0" if there's only one output? Is it called that in the
> documentation? I had a quick check but only saw it called "vout".
> Are there other related devices that would have multiple regulators
> that might end up sharing the binding?
> 

Primarily because that is what the PMBus core generates for the driver
because no one including me was aware that this is unacceptable
for single-output drivers. We now have commit 88b5970e92d0 ("hwmon:
(pmbus/core) Add helper macro to define single pmbus regulator").
I guess we can update the tda38640 driver to use the new macro
to register vout instead of vout0.

Guenter
  

On Wed, Feb 14, 2024 at 10:48:52AM -0800, Guenter Roeck wrote:
> On 2/14/24 09:51, Conor Dooley wrote:
> > On Wed, Feb 14, 2024 at 02:55:03PM +0530, Naresh Solanki wrote:
> > > Add properties for interrupt & regulator.
> > > Also update example.
> > 
> > I feel like a broken record. Your patches need to explain _why_ you're
> > doing what you're doing. I can read the diff and see this, but I do not
> > know what the justification for it is.
> > 
> > /30 seconds later
> > I really am a broken record, to quote from v1:
> > | Feeling like a broken record, given I am leaving the same comments on
> > | multiple patches. The commit message needs to explain why you're doing
> > | something. I can read the diff and see what you did!
> > 
> > https://lore.kernel.org/all/20240126-fleshed-subdued-36bae813e2ba@spud/
> > 
> > The patch itself does look better than the v1, with one minor comment
> > below.
> > 
> > Thanks,
> > Conor.
> > 
> > > Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
> > > 
> > > ---
> > > Changes in v2:
> > > 1. Remove TEST=..
> > > 2. Update regulator subnode property as vout0
> > > 3. Restore commented line in example
> > > 4. blank line after interrupts property in example.
> > > ---
> > >   .../hwmon/pmbus/infineon,tda38640.yaml        | 28 +++++++++++++++++++
> > >   1 file changed, 28 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
> > > index ded1c115764b..a93b3f86ee87 100644
> > > --- a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
> > > +++ b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
> > > @@ -30,6 +30,23 @@ properties:
> > >         unconnected(has internal pull-down).
> > >       type: boolean
> > > +  interrupts:
> > > +    maxItems: 1
> > > +
> > > +  regulators:
> > > +    type: object
> > > +    description:
> > > +      list of regulators provided by this controller.
> > > +
> > > +    properties:
> > > +      vout0:
> > 
> > Why "vout0" if there's only one output? Is it called that in the
> > documentation? I had a quick check but only saw it called "vout".
> > Are there other related devices that would have multiple regulators
> > that might end up sharing the binding?
> > 
> 
> Primarily because that is what the PMBus core generates for the driver
> because no one including me was aware that this is unacceptable
> for single-output drivers.

Is it unacceptable? If you're implying that I am saying it is, that's
not what I was doing here - I'm just wondering why it was chosen.
Numbering when there's only one seems odd, so I was just looking for the
rationale.

> We now have commit 88b5970e92d0 ("hwmon:
> (pmbus/core) Add helper macro to define single pmbus regulator").
> I guess we can update the tda38640 driver to use the new macro
> to register vout instead of vout0.
  

On 2/14/24 11:55, Conor Dooley wrote:
[ ... ]
>>> Why "vout0" if there's only one output? Is it called that in the
>>> documentation? I had a quick check but only saw it called "vout".
>>> Are there other related devices that would have multiple regulators
>>> that might end up sharing the binding?
>>>
>>
>> Primarily because that is what the PMBus core generates for the driver
>> because no one including me was aware that this is unacceptable
>> for single-output drivers.
> 
> Is it unacceptable? If you're implying that I am saying it is, that's
> not what I was doing here - I'm just wondering why it was chosen.
> Numbering when there's only one seems odd, so I was just looking for the
> rationale.
> 

Given the tendency of corporate speak (aka "this was a good attempt" for
a complete screwup), and since this did come up before, I did interpret
it along that line. My apologies if that was not the idea.

Still, I really don't know how to resolve this for existing PMBus drivers
which do register "vout0" even if there is only a single output regulator.

Guenter
  

On Wed, Feb 14, 2024 at 05:17:04PM -0800, Guenter Roeck wrote:
> On 2/14/24 11:55, Conor Dooley wrote:
> [ ... ]
> > > > Why "vout0" if there's only one output? Is it called that in the
> > > > documentation? I had a quick check but only saw it called "vout".
> > > > Are there other related devices that would have multiple regulators
> > > > that might end up sharing the binding?
> > > > 
> > > 
> > > Primarily because that is what the PMBus core generates for the driver
> > > because no one including me was aware that this is unacceptable
> > > for single-output drivers.
> > 
> > Is it unacceptable? If you're implying that I am saying it is, that's
> > not what I was doing here - I'm just wondering why it was chosen.
> > Numbering when there's only one seems odd, so I was just looking for the
> > rationale.
> > 
> 
> Given the tendency of corporate speak (aka "this was a good attempt" for
> a complete screwup), and since this did come up before, I did interpret
> it along that line. My apologies if that was not the idea.

I'm not gonna go and decree that "vout0" is unacceptable, if it was
called that in documentation that I had missed or was convention, I was
just gonna say "okay, that sounds reasonable to me".

> Still, I really don't know how to resolve this for existing PMBus drivers
> which do register "vout0" even if there is only a single output regulator.

I had a quick look at that series, none of the devices that I checked
out there seem to have documented regulators at all. Some of the devices
were only documented in trivial-devices.yaml. Relying on the naming of
undocumented child nodes is a bug in those drivers & I guess nobody cares
about dtbs_check complaints for those platforms. The example that was
linked in the other thread doesn't even use a valid compatible :(
	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/aspeed/aspeed-bmc-delta-ahe50dc.dts?id=8d3dea210042f54b952b481838c1e7dfc4ec751d#n21
I guess it uses the i2c device ids to probe on that platform, or have
I missed something there?

Cheers,
Conor.
  

On 2/15/24 03:48, Conor Dooley wrote:
> On Wed, Feb 14, 2024 at 05:17:04PM -0800, Guenter Roeck wrote:
>> On 2/14/24 11:55, Conor Dooley wrote:
>> [ ... ]
>>>>> Why "vout0" if there's only one output? Is it called that in the
>>>>> documentation? I had a quick check but only saw it called "vout".
>>>>> Are there other related devices that would have multiple regulators
>>>>> that might end up sharing the binding?
>>>>>
>>>>
>>>> Primarily because that is what the PMBus core generates for the driver
>>>> because no one including me was aware that this is unacceptable
>>>> for single-output drivers.
>>>
>>> Is it unacceptable? If you're implying that I am saying it is, that's
>>> not what I was doing here - I'm just wondering why it was chosen.
>>> Numbering when there's only one seems odd, so I was just looking for the
>>> rationale.
>>>
>>
>> Given the tendency of corporate speak (aka "this was a good attempt" for
>> a complete screwup), and since this did come up before, I did interpret
>> it along that line. My apologies if that was not the idea.
> 
> I'm not gonna go and decree that "vout0" is unacceptable, if it was
> called that in documentation that I had missed or was convention, I was
> just gonna say "okay, that sounds reasonable to me".
> 

"convention" only if lack of awareness how regulators are supposed to be named
is a convention.

>> Still, I really don't know how to resolve this for existing PMBus drivers
>> which do register "vout0" even if there is only a single output regulator.
> 
> I had a quick look at that series, none of the devices that I checked
> out there seem to have documented regulators at all. Some of the devices
> were only documented in trivial-devices.yaml. Relying on the naming of
> undocumented child nodes is a bug in those drivers & I guess nobody cares
> about dtbs_check complaints for those platforms. The example that was
> linked in the other thread doesn't even use a valid compatible :(
> 	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/aspeed/aspeed-bmc-delta-ahe50dc.dts?id=8d3dea210042f54b952b481838c1e7dfc4ec751d#n21
> I guess it uses the i2c device ids to probe on that platform, or have
> I missed something there?
> 

I think that is correct. If I recall correctly, the I2C subsystem no longer
searches for compatible drivers by only looking at the device id in the
compatible node, so I guess one has to list "lm25066" instead of "ti,lm25066"
as compatible to get a match in the i2c subsystem. That is of course
completely wrong.

Guenter
  

On Sat, Feb 17, 2024 at 07:57:43AM -0800, Guenter Roeck wrote:
> On 2/15/24 03:48, Conor Dooley wrote:
> > On Wed, Feb 14, 2024 at 05:17:04PM -0800, Guenter Roeck wrote:
> > > On 2/14/24 11:55, Conor Dooley wrote:
> > > [ ... ]
> > > > > > Why "vout0" if there's only one output? Is it called that in the
> > > > > > documentation? I had a quick check but only saw it called "vout".
> > > > > > Are there other related devices that would have multiple regulators
> > > > > > that might end up sharing the binding?
> > > > > > 
> > > > > 
> > > > > Primarily because that is what the PMBus core generates for the driver
> > > > > because no one including me was aware that this is unacceptable
> > > > > for single-output drivers.
> > > > 
> > > > Is it unacceptable? If you're implying that I am saying it is, that's
> > > > not what I was doing here - I'm just wondering why it was chosen.
> > > > Numbering when there's only one seems odd, so I was just looking for the
> > > > rationale.
> > > > 
> > > 
> > > Given the tendency of corporate speak (aka "this was a good attempt" for
> > > a complete screwup), and since this did come up before, I did interpret
> > > it along that line. My apologies if that was not the idea.
> > 
> > I'm not gonna go and decree that "vout0" is unacceptable, if it was
> > called that in documentation that I had missed or was convention, I was
> > just gonna say "okay, that sounds reasonable to me".
> > 
> 
> "convention" only if lack of awareness how regulators are supposed to be named
> is a convention.

They're "supposed" to be named whatever the binding says they are named,
but as we've discovered none of these devices actually have bindings
that allow regulators in the first place. I think they should be called
whatever they're called in the documentation for the device, which in
this case was "vout".

> > > Still, I really don't know how to resolve this for existing PMBus drivers
> > > which do register "vout0" even if there is only a single output regulator.
> > 
> > I had a quick look at that series, none of the devices that I checked
> > out there seem to have documented regulators at all. Some of the devices
> > were only documented in trivial-devices.yaml. Relying on the naming of
> > undocumented child nodes is a bug in those drivers & I guess nobody cares
> > about dtbs_check complaints for those platforms. The example that was
> > linked in the other thread doesn't even use a valid compatible :(
> > 	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/aspeed/aspeed-bmc-delta-ahe50dc.dts?id=8d3dea210042f54b952b481838c1e7dfc4ec751d#n21
> > I guess it uses the i2c device ids to probe on that platform, or have
> > I missed something there?
> > 
> 
> I think that is correct. If I recall correctly, the I2C subsystem no longer
> searches for compatible drivers by only looking at the device id in the
> compatible node, so I guess one has to list "lm25066" instead of "ti,lm25066"
> as compatible to get a match in the i2c subsystem. That is of course
> completely wrong.

If the driver is probing based on i2c_device_id matching, is it correct to
use DT to probe the regulators? (I don't know, that's not some sort of
rhetorical question).
  

On 2/17/24 12:30, Conor Dooley wrote:
> On Sat, Feb 17, 2024 at 07:57:43AM -0800, Guenter Roeck wrote:
>> On 2/15/24 03:48, Conor Dooley wrote:
>>> On Wed, Feb 14, 2024 at 05:17:04PM -0800, Guenter Roeck wrote:
>>>> On 2/14/24 11:55, Conor Dooley wrote:
>>>> [ ... ]
>>>>>>> Why "vout0" if there's only one output? Is it called that in the
>>>>>>> documentation? I had a quick check but only saw it called "vout".
>>>>>>> Are there other related devices that would have multiple regulators
>>>>>>> that might end up sharing the binding?
>>>>>>>
>>>>>>
>>>>>> Primarily because that is what the PMBus core generates for the driver
>>>>>> because no one including me was aware that this is unacceptable
>>>>>> for single-output drivers.
>>>>>
>>>>> Is it unacceptable? If you're implying that I am saying it is, that's
>>>>> not what I was doing here - I'm just wondering why it was chosen.
>>>>> Numbering when there's only one seems odd, so I was just looking for the
>>>>> rationale.
>>>>>
>>>>
>>>> Given the tendency of corporate speak (aka "this was a good attempt" for
>>>> a complete screwup), and since this did come up before, I did interpret
>>>> it along that line. My apologies if that was not the idea.
>>>
>>> I'm not gonna go and decree that "vout0" is unacceptable, if it was
>>> called that in documentation that I had missed or was convention, I was
>>> just gonna say "okay, that sounds reasonable to me".
>>>
>>
>> "convention" only if lack of awareness how regulators are supposed to be named
>> is a convention.
> 
> They're "supposed" to be named whatever the binding says they are named,
> but as we've discovered none of these devices actually have bindings
> that allow regulators in the first place. I think they should be called
> whatever they're called in the documentation for the device, which in
> this case was "vout".
> 

I would agree. I'd even submit a yaml file extension for the affected drivers
to address that, but I realize that I am notoriously bad with doing that,
so I won't even try.

>>>> Still, I really don't know how to resolve this for existing PMBus drivers
>>>> which do register "vout0" even if there is only a single output regulator.
>>>
>>> I had a quick look at that series, none of the devices that I checked
>>> out there seem to have documented regulators at all. Some of the devices
>>> were only documented in trivial-devices.yaml. Relying on the naming of
>>> undocumented child nodes is a bug in those drivers & I guess nobody cares
>>> about dtbs_check complaints for those platforms. The example that was
>>> linked in the other thread doesn't even use a valid compatible :(
>>> 	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/aspeed/aspeed-bmc-delta-ahe50dc.dts?id=8d3dea210042f54b952b481838c1e7dfc4ec751d#n21
>>> I guess it uses the i2c device ids to probe on that platform, or have
>>> I missed something there?
>>>
>>
>> I think that is correct. If I recall correctly, the I2C subsystem no longer
>> searches for compatible drivers by only looking at the device id in the
>> compatible node, so I guess one has to list "lm25066" instead of "ti,lm25066"
>> as compatible to get a match in the i2c subsystem. That is of course
>> completely wrong.
> 
> If the driver is probing based on i2c_device_id matching, is it correct to
> use DT to probe the regulators? (I don't know, that's not some sort of
> rhetorical question).

Looking into the lm25066 driver, it actually does support the "ti,lm25066"
compatible. Given that, I don't know why the dts file doesn't use it, especially
since the dts file was created after the compatible entry was added to the
lm25066 driver.

Guenter