From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?U8O2cmVu?= Brinkmann Subject: Re: [RFC PATCH 3/3] devicetree: macb: Add optional property tsu-clk Date: Mon, 14 Sep 2015 07:44:23 -0700 Message-ID: <20150914144423.GG19678@xsjsorenbubuntu> References: <1441958258-35441-1-git-send-email-harinik@xilinx.com> <1441958258-35441-4-git-send-email-harinik@xilinx.com> <20150911165256.GT19678@xsjsorenbubuntu> <20150914095846.0d8e2d74@bbrezillon> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20150914095846.0d8e2d74@bbrezillon> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Boris Brezillon Cc: Harini Katakam , Harini Katakam , Nicolas Ferre , davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org, Rob Herring , Pawel Moll , Mark Rutland , "ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org" , Kumar Gala , alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Punnaiah Choudary Kalluri , "michals-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org" , anirudh-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, 2015-09-14 at 09:58AM +0200, Boris Brezillon wrote: > Hi Harini, >=20 > On Mon, 14 Sep 2015 09:39:05 +0530 > Harini Katakam wrote: >=20 > > On Fri, Sep 11, 2015 at 10:22 PM, S=C3=B6ren Brinkmann > > wrote: > > > Hi Harini, > > > > > > On Fri, 2015-09-11 at 01:27PM +0530, Harini Katakam wrote: > > >> Add TSU clock frequency to be used for 1588 support in macb driv= er. > > >> > > >> Signed-off-by: Harini Katakam > > >> --- > > >> Documentation/devicetree/bindings/net/macb.txt | 3 +++ > > >> 1 file changed, 3 insertions(+) > > >> > > >> diff --git a/Documentation/devicetree/bindings/net/macb.txt b/Do= cumentation/devicetree/bindings/net/macb.txt > > >> index b5d7976..f7c0ea8 100644 > > >> --- a/Documentation/devicetree/bindings/net/macb.txt > > >> +++ b/Documentation/devicetree/bindings/net/macb.txt > > >> @@ -19,6 +19,9 @@ Required properties: > > >> Optional elements: 'tx_clk' > > >> - clocks: Phandles to input clocks. > > >> > > >> +Optional properties: > > >> +- tsu-clk: Time stamp unit clock frequency used. > > > > > > Why are we not using the CCF and a clk_get_rate() in the driver? > > > > >=20 > > If the clock source was only internal, we could use this > > approach as usual. But TSU clock can be configured to > > come from an external clock source or internal. >=20 > How about declaring a fixed-rate clk [1] if it comes from an external > clk, and using a clk driver for the internal clk case? > This way you'll be able to use the clk API (including the > clk_get_rate() function) instead of introducing a new way to retrieve= a > clk frequency. Right. Also, Zynq does already support external clock inputs (actually, every clock originates from some external clock/oscillator at some point). Maybe that code needs some additions to handle the TSU clock too. But either way, I can't see why a clock cannot be modeled using th= e CCF. S=C3=B6ren -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html