[PATCH v2 1/5] ARM: PXA: Add z2-usb-switch driver

Marek Vasut marex at denx.de
Sun Oct 28 18:48:48 EDT 2012


Dear Vasily Khoruzhick,

> On Mon, Oct 29, 2012 at 1:38 AM, Marek Vasut <marex at denx.de> wrote:
> > Dear Vasily Khoruzhick,
> > 
> >> On Mon, Oct 29, 2012 at 12:57 AM, Marek Vasut <marex at denx.de> wrote:
> >> > Dear Vasily Khoruzhick,
> >> 
> >> Dear Marek Vasut,
> >> 
> >> >> This driver controls mode of USB port #2 pins - device or host.
> >> > 
> >> > Please supply proper commit message. This short message describes
> >> > nothing.
> >> 
> >> OK, "This driver allows user to choose USB port #2 mode between device
> >> and host" - that would be OK?
> > 
> > Please describe why is this needed at all and what it does.
> 
> Because one might need USB device and USB host functionality provided
> by USB port #2?
> It switches pins mode from device to host and backwards.

Good, now compile it into the commit message for v3 please.

> > [...]
> > 
> >> > I wonder if we have no better means to control enforcement of mode.
> >> 
> >> Why? sysfs fits nicely.
> > 
> > Because if there is already an API to implement this OTG in kernel, you
> > should use that and not reinvent wheel.
> 
> One needs to select USB mode manually (btw, Z2 can't even power USB
> device properly, only 3.3v or external 5v).
> There's no way to determine what type of device (device/host)
> connected to Z2 at the moment.

Good, so your OTG is software controlled.

[...]

Best regards,
Marek Vasut



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