Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
From: Jon Hunter <hidden>
Date: 2016-11-07 14:12:12
Also in:
linux-arm-kernel, linux-tegra, lkml
On 07/11/16 13:28, Thierry Reding wrote:
* PGP Signed by an unknown key On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:quoted
Nyan boards only have host USB ports (2 external, 1 internal), there is no OTG-enabled connector. Signed-off-by: Paul Kocialkowski <redacted> --- arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)Where is this information coming from? I don't have one of the Nyans myself, but one of the Tegra132 devices I have, which I think was derived from one of the Nyans uses one of the external host ports as forced recovery port, for which it would need OTG. I suspect that the way to get U-Boot onto the Nyans is via tegrarcm? In that case I think one of the ports must be OTG.
It is true that the port on the back on the nyan-big can be used with recovery mode. I was thinking that this is not a true OTG port as it is just a 4-pin type A socket and does not have an ID pin. Thinking some more about this the USB spec does include a "Host Negotiation Protocol (HNP)" that allows a host and device to swap roles and so keeping it as OTG seems valid afterall. Cheers Jon -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html