Re: [PATCH v6 14/15] usb: host: xhci-tegra: Unlink power domain devices

[Thierry Reding]

On Tue, Jan 19, 2021 at 04:55:45PM +0800, JC Kuo wrote:
> This commit unlinks xhci-tegra platform device with SS/host power
> domain devices. Reasons for this change is - at ELPG entry, PHY
> sleepwalk and wake configuration need to be done before powering
> down SS/host partitions, and PHY need be powered off after powering
> down SS/host partitions. Sequence looks like roughly below:
> 
>   tegra_xusb_enter_elpg() -> xhci_suspend()
>                           -> enable PHY sleepwalk and wake if needed
>                           -> power down SS/host partitions
>                           -> power down PHY
> 
> If SS/host power domains are linked to xhci-tegra platform device, we
> are not able to perform the sequence like above.
> 
> This commit introduces:
>   1. tegra_xusb_unpowergate_partitions() to power up SS and host
>      partitions together. If SS/host power domain devices are
>      available, it invokes pm_runtime_get_sync() to request power
>      driver to power up partitions; If power domain devices are not
>      available, tegra_powergate_sequence_power_up() will be used to
>      power up partitions.
> 
>   2. tegra_xusb_powergate_partitions() to power down SS and host
>      partitions together. If SS/host power domain devices are
>      available, it invokes pm_runtime_put_sync() to request power
>      driver to power down partitions; If power domain devices are not
>      available, tegra_powergate_power_off() will be used to power down
>      partitions.
> 
> Signed-off-by: JC Kuo <jckuo@xxxxxxxxxx>

Acked-by: Thierry Reding <treding@xxxxxxxxxx>

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