[Arm-netbook] irony: requirement for 100 A10 PCBs with GPIO-controlled power-up on USB 5V rail, or a Mini-PCIe socket

[Alejandro Mery]

On 28 November 2012 21:13, Zsolt Sztupák <mail at sztupy.hu> wrote:
> 2012.11.28. 20:55 keltezéssel, Emilio López írta:
>> El 28/11/12 15:41, luke.leighton escribió:
>>> hi folks,
>>>
>>> part of the reason why things are very busy for me at the moment is
>>> because i've started a new job, and - irony - they need a small
>>> low-cost unit, qty 100, with 3G (HSDPA) and WIFI (802.11bgn).
>>>
>>> but the requirements are *very* specific: the WIFI and 3G, which are
>>> usually USB-powered, typically crash (for whatever reason) but they're
>>> often 5V powered and you can't shut them down.
>>>
>>> so what they need to be able to do is to flick a couple of GPIO pins
>>> and power off - completely - the USB bus 5V rail.  or, if the unit has
>>> a Mini PCIe slot for 3G, they need to be able to pull down the 3.3v
>>> and 1.5v power, and back up again.
>>>
>>> it's the basis of a reliable router box, basically.  oh - they also
>>> need Ethernet.
>>>
>>> so - irony, as the timescales are short, i'm looking at the hackberry,
>>> and yes tom the cubieboard: i need to find absolutely anything where
>>> the USB can be completely powered down, *without* power-cycling.
>> I'm pretty sure that's how the USB WiFi chip operates on A10 tablets,
>> when you unload the module, the usb power for the device is disconnected.
>>
>> Look for sw_usb_* on
>> drivers/net/wireless/rtl8192cu/os_dep/linux/usb_intf.c for an example.
>>
> I recently saw an im5x based android e-ink tablet from china, where the
> wifi and 3G chips could be powered-down and up using proprietary kernel
> ioctls (and yes, no source was provided for this kernel driver of course)

allwinner powers off the usbc where the wifi chip is connected