[PATCH 1/3] usb: core: add power sequence for USB devices

[Peter Chen]

On Mon, Mar 14, 2016 at 6:42 PM, Peter Chen <hzpeterchen at gmail.com> wrote:
> On Sat, Mar 05, 2016 at 03:10:11PM +0100, Andrew Lunn wrote:
>> > So, would you like to accept the generic solution like below:
>> >
>> > - Create a generic power sequence driver, and it will be probed
>> > according to compatible string at device tree. At its probe,
>> > we can create a power sequence structure, and let this structure
>> > as the private data for this power sequence device.
>>
>> I'm not sure a separate driver is required. Why not consider it more
>> like pinctrl properties? They are listed in the devices node. Have the
>> bus enumerate code first walk all children and run their on sequence.
>> Bus shutdown would again walk the children and run the off sequence.
>>
>
> The device which needs power sequence may not at platform bus, it may
> be at USB bus, MMC bus, etc.
>
> From what I see, A generic pwrseq driver can cover gpio-en, gpio-rst, clock,
> clock-freq, etc, but I find the pwrseq_emmc does something special, like
> request a restart handler.
>
> Add Ulf, who is the power sequence author for MMC.
>
> Hi Ulf, Rob suggested that if we can create some generic things (driver
> or library) for power sequence for all devices, what do you think?
>
> --
>
> Best Regards,
> Peter Chen

ping....

Any more comments? If no, I will try to create some generic stuffs for
power sequence.

-- 
BR,
Peter Chen