From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v1 5/9] of: Add NVIDIA Tegra XHCI controller binding Date: Wed, 25 Jun 2014 17:14:53 -0600 Message-ID: <53AB57ED.7080600@wwwdotorg.org> References: <1403072180-4944-1-git-send-email-abrestic@chromium.org> <1403072180-4944-6-git-send-email-abrestic@chromium.org> <53AB4530.2050106@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andrew Bresticker Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Randy Dunlap , Thierry Reding , Russell King , Linus Walleij , Greg Kroah-Hartman , Mathias Nyman , Grant Likely , Alan Stern , Kishon Vijay Abraham I , Arnd Bergmann List-Id: devicetree@vger.kernel.org On 06/25/2014 05:02 PM, Andrew Bresticker wrote: > On Wed, Jun 25, 2014 at 2:54 PM, Stephen Warren wrote: >> On 06/18/2014 12:16 AM, Andrew Bresticker wrote: >>> Add device-tree binding documentation for the XHCI controller present >>> on Tegra124 and later SoCs. >> >>> diff --git a/Documentation/devicetree/bindings/usb/nvidia,tegra124-xhci.txt b/Documentation/devicetree/bindings/usb/nvidia,tegra124-xhci.txt >> >>> + - clock-names: Must include the following entries: >>> + - xusb_host >>> + - xusb_falcon_src >>> + - xusb_ss >>> + - xusb_ss_src >>> + - xusb_hs_src >>> + - xusb_fs_src >> >> Looking at include/dt-bindings/clock/tegra124-car.h I see a few entries >> potentially missing here: >> >> #define TEGRA124_CLK_XUSB_HOST_SRC 252 >> #define TEGRA124_CLK_XUSB_DEV_SRC 256 >> #define TEGRA124_CLK_XUSB_DEV 257 >> #define TEGRA124_CLK_XUSB_SS_DIV2 312 > > The driver doesn't use them, so I didn't put them in the binding. I think we should add them in case we need them later. Best to fully describe the HW rather than the parts of the HW that SW currently uses. >>> + - pll_u_480m >> >> Not just pll_u? > > We specifically want pll_u_480M as that's what we use as the parent of > xusb_ss_src when scaling it to 120Mhz. OK. I recall text in the TRM implying that SW should just leave PLL_U alone and not fiddle with the separate output clocks. Still, if we have a clock ID for each output, and it's the correct parent for the clock, then it does make sense to use that ID. -- 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