Re: [PATCH v3 2/2] pmic: pca9450: Add regulator driver

["Vaittinen, Matti" <Matti.Vaittinen@fi.rohmeurope.com>]

On 6/20/22 05:47, Marek Vasut wrote:
> On 6/19/22 18:01, Heiko Thiery wrote:
> 
> [...]
> 
>>>> +static int pca9450_set_value(struct udevice *dev, int uvolt)
>>>> +{
>>>> +       struct pca9450_plat *plat = dev_get_plat(dev);
>>>> +       unsigned int sel;
>>>> +       int i, found = 0;
>>>> +
>>>> +       /*
>>>> +        * An under/overshooting may occur if voltage is changed for 
>>>> other
>>>> +        * regulators but buck 1,2,3 or 4 when regulator is enabled. 
>>>> Prevent
>>>> +        * change to protect the HW
>>>> +        */
>>>
>>> To be able to configure the pmic/regulators during startup by the dm
>>> (regulators_enable_boot_on) I think we have to
>>> remove the checks for the permit. Otherwise the automatic 
>>> configuration on hand
>>> of the dtb settings won't work.
>>>
>>
>> I tried to find the root of the comment above. Since the driver is
>> probably based
>> on the ROHM BD71837 and this comment can be found there as well, the
>> limitation probably comes from this type.
>>
>> Can this be?
> 
> Most likely this comment is bogus copy-paste from the ROHM PMIC driver.
> 
> [...]

I've authored this commit in the ROHM BD71837 driver. The ROHM PMIC do 
really have this limitation - only BUCKs 1,2,3 and 4 have been designed 
for changing the voltage when enabled.

I do not know about pca9450 - but I can assure that if copy-paste has 
happened the direction has indeed been ROHM driver => pca9450 :)

Best Regards
	-- Matti Vaittinen

-- 
The Linux Kernel guy at ROHM Semiconductors

Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

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