[Meego-kernel] [PATCH 5/5] tc35894xbg: add runtime pm support

[Tardy, Pierre]

Bin Yang,

> This patch add keypad runtime pm support.
> As a keypad driver, it will never go to power down mode. HW will goto power saving mode
> when there is no key pressed. So the runtime pm callback functions do nothing.

If you dont do anything special for runtime_pm, there is no need to implement runtime_pm in your driver.
This is just consuming cpu cycles, and code size for nothing.

A child with runtime_pm disabled (the default for a non runtime_pm supporting driver) will not prevent his parent to correctly go runtime_suspend.

The only reason you would like to implement runtime_pm is to do more high level get() and set(), that would prevent thrashing of the parent. (e.g keep the parent active when there is a sequence of i2c transfer known by the child)
You don't have any put and get in your patch, so your driver will show suspended all the time.

Regards,
Pierre


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