From mboxrd@z Thu Jan 1 00:00:00 1970 From: hdegoede@redhat.com (Hans de Goede) Date: Wed, 21 Sep 2016 10:30:24 +0300 Subject: [PATCH 1/2] dt: bindings: add allwinner,otg-routed property for phy-sun4i-usb In-Reply-To: <6718551474442396@web16h.yandex.ru> References: <20160921070406.27445-1-icenowy@aosc.xyz> <4a1ab62a-4091-fd75-d753-fb30585dffa5@redhat.com> <6718551474442396@web16h.yandex.ru> Message-ID: <43caf5c6-0198-9178-de93-90dc25e8b72b@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On 09/21/2016 10:19 AM, Icenowy Zheng wrote: > > > 21.09.2016, 15:10, "Hans de Goede" : >> Hi, >> >> On 09/21/2016 10:04 AM, Icenowy Zheng wrote: >>> On some newer Allwinner SoCs (H3 or A64), the PHY0 can be either routed to >>> the MUSB controller (which is an OTG controller) or the OHCI/EHCI pair >>> (which is a Host-only controller, but more stable and easy to implement). >>> >>> This property marks whether on a certain board which controller should be >>> attached to the PHY. >>> >>> Signed-off-by: Icenowy Zheng >> >> Erm, I think that the idea here is to dynamically switch the routing >> based on the id-pin of the otg connector. IOW use the musb controller >> for device mode, and the ehci/ohci proper for proper host support >> when in host mode. > > At least on some boards this implementation works... > > (I mean Pine64, which has two USB-A connectors) Right and I think it is great that you're working on this. But even with an A connector on the board, we can still use the device mode (e.g. the SoC's native FEL mode will be used this way). Notice that you can fake id-pin changes by echoing a mode to: /sys/devices/platform/soc at 01c00000/1c13000.usb/musb-hdrc.1.auto/mode Valid values to echo are: host, peripheral and otg. If you combine this with using either an USB A<->A cable, or using the port normally as a host you should be able to develop and test full otg support. Eventually we will need a full otg support rather then your current solution and I'm afraid that your solution may get in the way of full otg support. Regards, Hans