From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH v2 2/3] ehci-platform: Add support for controllers with multiple reset lines Date: Fri, 11 Dec 2015 19:28:07 +0100 Message-ID: <566B15B7.40703@redhat.com> References: <1449848520-27379-1-git-send-email-hdegoede@redhat.com> <1449848520-27379-2-git-send-email-hdegoede@redhat.com> <1449853984.3419.52.camel@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1449853984.3419.52.camel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Philipp Zabel Cc: Josh Triplett , Rashika Kheria , Stephen Warren , Maxime Ripard , Greg Kroah-Hartman , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Roger Quadros , Alan Stern , Tony Prisk , Florian Fainelli , linux-usb , devicetree , Chen-Yu Tsai , Reinder de Haan List-Id: devicetree@vger.kernel.org Hi, On 11-12-15 18:13, Philipp Zabel wrote: > Am Freitag, den 11.12.2015, 16:41 +0100 schrieb Hans de Goede: >> From: Reinder de Haan >> >> At least the EHCI/OHCI found on the Allwinnner H3 SoC needs multiple >> reset lines, the controller will not initialize while the reset for >> its companion is still asserted, which means we need to de-assert >> 2 resets for the controller to work. >> >> Signed-off-by: Reinder de Haan >> Signed-off-by: Hans de Goede >> --- >> Changes in v2: >> -Use the new reset_control_[de]assert_shared reset-controller functions >> --- >> Documentation/devicetree/bindings/usb/usb-ehci.txt | 2 +- >> drivers/usb/host/ehci-platform.c | 47 +++++++++++++--------- >> 2 files changed, 30 insertions(+), 19 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt >> index a12d601..0701812 100644 >> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt >> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt >> @@ -18,7 +18,7 @@ Optional properties: >> - clocks : a list of phandle + clock specifier pairs >> - phys : phandle + phy specifier pair >> - phy-names : "usb" >> - - resets : phandle + reset specifier pair >> + - resets : a list of phandle + reset specifier pairs > > Are there documented names for these resets? This binding is a generic ehci controller binding, so even if the names are documented for the allwinner SoC we should not use names, just like the binding is deliberately not using names for the clocks either to keep it generic, so that we can reuse the binding + driver with many different SoCs. > Is the companion you > mention the Port Control? Sort of, with USB-2, USB-1 compatibility is handled via a mux on the datalines (controlled by the EHCI controller Port Control) which muxes the lines to an USB-1 controller (typically either UHCI or OHCI) when the device does not connect after USB-2 highspeed handshaking. This USB-1 controller (or controller_S_ in some case since the USB-1 companions may have less root-ports per controller then the EHCI has root-ports) is called the companion controller. The 2 controllers are supposed to be 100% independent but on the H3 Allwinner has done something (not documented) which requires one to deassert reset on both before you can talk to either one. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html