Thread (10 messages) 10 messages, 4 authors, 2016-11-08

[PATCH] ARM: tegra: nyan: Mark all USB ports as host

From: jonathanh@nvidia.com (Jon Hunter)
Date: 2016-11-07 14:12:12
Also in: linux-devicetree, 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
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