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Date:   Wed, 9 Nov 2022 15:59:06 -0600
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Subject: Re: [PATCH v6 4/6] mfd: tps65219: Add driver for TI TPS65219 PMIC
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To:     Kevin Hilman <khilman@baylibre.com>, Nishanth Menon <nm@ti.com>,
        jerome Neanne <jneanne@baylibre.com>
CC:     Lee Jones <lee@kernel.org>, <lgirdwood@gmail.com>,
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References: <20221011140549.16761-1-jneanne@baylibre.com>
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 <20221105000104.rtj3r6ufqwqmepon@keenly> <7heduewjp0.fsf@baylibre.com>
From:   Andrew Davis <afd@ti.com>
In-Reply-To: <7heduewjp0.fsf@baylibre.com>
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On 11/7/22 3:14 PM, Kevin Hilman wrote:
> Nishanth Menon <nm@ti.com> writes:
> 
>> On 13:58-20221104, jerome Neanne wrote:
>>>
>> [...]
>>
>>>
>>>>
>>>> Can you try an compile with W=1 please.
>>> This raise one warning on mfd:
>>> drivers/mfd/tps65219.c:28:12: warning: ‘tps65219_soft_shutdown’ defined but
>>> not used [-Wunused-function]
>>>     28 | static int tps65219_soft_shutdown(struct tps65219 *tps)
>>>        |            ^~~~~~~~~~~~~~~~~~~~~~
>>> soft_shutdown has been validated and is used in TI baseline even if not
>>> hooked in upstream version further to this review:
>>> https://lore.kernel.org/lkml/20220825150224.826258-5-msp@baylibre.com/
>>>
>>> It was a TI requirement to implement it...
>>> Let me know if you want me to remove this function or if we can keep it like
>>> this.
>>
>> There are platforms without psci, correct? I think the comment was to
>> drop the force override with system-power-controller property,
>>
>> if (!pm_power_off) {
>> 	tps65219_i2c_client = client;
>> 	pm_power_off = &tps65219_pm_power_off;
>> }
>>
>> Could still be valid for such platforms, no? I do see that the
>> capability that the PMIC has - which is software shutdown is a valid
>> feature that we support in many different PMIC drivers. Is'nt the job of
>> the driver to introduce the functionality in a manner that is
>> appropriate to the OS framework?
> 
> Yeah, I think Nishanth is right here.
> 
> We should probably keep the `if (!pm_power_off)` part so the PMIC will
> be used if PSCI is not, but it also allows an easy way to test/use the PMIC
> shutdown functionality downstream if needed.
> 

Then should be using the sys-off handler API[0] so it doesn't block PSCI
which is also switching over[1].

Andrew

[0] https://lwn.net/Articles/894511/
[1] https://www.spinics.net/lists/arm-kernel/msg1024127.html