From mboxrd@z Thu Jan 1 00:00:00 1970 From: Justin Chen Subject: Re: [PATCH 1/2] watchdog: bcm7038: add device tree binding documentation Date: Tue, 25 Aug 2015 10:55:40 -0700 Message-ID: <20150825175538.GA16266@Justins-MacBook-Pro.local> References: <1440092486-16905-1-git-send-email-justinpopo6@gmail.com> <1440092486-16905-2-git-send-email-justinpopo6@gmail.com> <55DA9045.2060107@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <55DA9045.2060107-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Guenter Roeck Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, feedback-list-dY08KVG/lbpWk0Htik3J/w@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, wim-IQzOog9fTRqzQB+pC5nmwQ@public.gmane.org, linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Sun, Aug 23, 2015 at 08:32:21PM -0700, Guenter Roeck wrote: > Hi Justin, > > On 08/20/2015 10:41 AM, Justin Chen wrote: > >Add device tree binding docmentation for the watchdog hardware block > >on bcm7038 and newer SoCs. > > > >Signed-off-by: Justin Chen > >--- > > .../devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt > > > >diff --git a/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt b/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt > >new file mode 100644 > >index 0000000..adb8260 > >--- /dev/null > >+++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt > >@@ -0,0 +1,19 @@ > >+BCM7038 Watchdog timer > >+ > >+Required properties: > >+ > >+- compatible : should be "brcm,bcm7038-wdt" > >+- reg : Specifies base physical address and size of the registers. > >+ > >+Optional properties: > >+ > >+- clocks: the clock running the watchdog > >+- clock-frequency: the rate of the clock > > Is 'clock-frequency' really needed (and useful), or would it make more sense > to expect the user to configure a fixed clock if nothing else is available ? > How do other drivers handle this ? > > Thanks, > Guenter > > >+ > >+Example: > >+ > >+watchdog { > >+ compatible = "brcm,bcm7038-wdt"; > >+ clocks = <&upg_fixed>; > >+ reg = <0xf040a7e8 0x16>; > >+}; > > > Hello Guenter, > Is 'clock-frequency' really needed (and useful), or would it make more sense > to expect the user to configure a fixed clock if nothing else is available ? > How do other drivers handle this ? The reason for 'clock-frequency' was for a case where our device tree did not have clocks. Creating a new fixed clock for a single device seems unnecessary compared to a 'clock-frequency' property. Their is a use for 'clock-frequency', but it is not really necessary. However, this is my first linux patch, so I do not fully trust my judgement on this... Looking at other drivers, none of them have both clock and clock-frequency. Thank you for your time on reviewing the patch Guenter. Much appreciated! Thanks, Justin Chen -- 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