Re: [PATCH 0/4] phy: samsung-usb2: Add support for Vbus regulator

[Vivek Gautam]

On Thu, Dec 11, 2014 at 5:52 PM, David Laight <David.Laight@xxxxxxxxxx> wrote:
> From: Vivek Gautam
>> This has been on my to-do list for sometime.
>> Until now the host controller (specifically ehci-exynos) is responsible
>> for enabling VBUS supply. This opens up one more issue which is, when
>> only ohci-exynos is enabled and ehci-exynosis disabled then VBUS was
>> never enabled (since ohci did not have the code to enabled the VBUS supply).
>>
>> Rather it should be wise to move the VBUS related stuff to phy driver and
>> let phy take care of enabling it.
>>
>> This patch series adds that VBUS regulator to phy-samsung-usb2 driver,
>> adds necessary binding information as well as vbus-supply properties
>> to phy nodes on exynos5250 systems.
> ...
>
> Does this go anyway to allowing devices to be powered from a micro-usb
> connector while acting as a USB host (USB OTG).
> ie when you want VBUS disabled even though it would normally
> need to be enabled.

Sorry i didn't get your second line.

This change allows HOST and HSIC phys to enable VBUS for the devices
connected to it.
Although now i think there can be a flaw in this approach
when only in OTG mode, when DEVICE phy is being used, even then
the regulator will be turned on causing power unnecessary consumption.




-- 
Best Regards
Vivek Gautam
Samsung R&D Institute, Bangalore
India
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