From mboxrd@z Thu Jan 1 00:00:00 1970 From: Piotr =?iso-8859-2?q?Zi=EAcik?= Subject: Re: [PATCH 08/12] mpc5121: Added I2C support. Date: Tue, 19 May 2009 09:47:22 +0200 Message-ID: <200905190947.22972.kosmo@semihalf.com> References: <1241640919-4650-1-git-send-email-wd@denx.de> <200905181557.11766.kosmo@semihalf.com> <4A1170B0.5080203@grandegger.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4A1170B0.5080203-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org> Content-Disposition: inline Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wolfgang Grandegger Cc: Grant Likely , Wolfgang Denk , linuxppc-dev-mnsaURCQ41sdnm+yROfE0A@public.gmane.org, Detlev Zundel , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Monday 18 May 2009 16:29:04 Wolfgang Grandegger napisa=B3(a): > > I have simple question about bus speed setting support. Existing > > implementation uses default safe speed if there is no 'clock-freque= ncy' > > property in i2c node. Comments in code suggest that this behaviour = is > > left for backward compatibility only. Should I make the 'clock-freq= uency' > > property mandatory for a new type of I2C controller (MPC5121) ? > > I don't think so, for the same backward compatibility reason as for t= he > other boards. But the DTS file might be changed to use clock-frequenc= y. In my opinion implementing "backward compatilility" for MPC5121 is not = good idea. MPC5121 I2C support is completly new thing in mainline. Simply, t= here is=20 no DTS with which I have to be compatible. Adding backward compatibilit= y with nothing may be confusing. --=20 Best Regards, Piotr Zi=EAcik From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from semihalf.com (semihalf.com [206.130.101.55]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id D90AADE0C8 for ; Tue, 19 May 2009 17:51:51 +1000 (EST) From: Piotr =?iso-8859-2?q?Zi=EAcik?= To: Wolfgang Grandegger Subject: Re: [PATCH 08/12] mpc5121: Added I2C support. Date: Tue, 19 May 2009 09:47:22 +0200 References: <1241640919-4650-1-git-send-email-wd@denx.de> <200905181557.11766.kosmo@semihalf.com> <4A1170B0.5080203@grandegger.com> In-Reply-To: <4A1170B0.5080203@grandegger.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Message-Id: <200905190947.22972.kosmo@semihalf.com> Cc: linuxppc-dev@ozlabs.org, Wolfgang Denk , Detlev Zundel , linux-i2c@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Monday 18 May 2009 16:29:04 Wolfgang Grandegger napisa=B3(a): > > I have simple question about bus speed setting support. Existing > > implementation uses default safe speed if there is no 'clock-frequency' > > property in i2c node. Comments in code suggest that this behaviour is > > left for backward compatibility only. Should I make the 'clock-frequenc= y' > > property mandatory for a new type of I2C controller (MPC5121) ? > > I don't think so, for the same backward compatibility reason as for the > other boards. But the DTS file might be changed to use clock-frequency. In my opinion implementing "backward compatilility" for MPC5121 is not good idea. MPC5121 I2C support is completly new thing in mainline. Simply, there= is=20 no DTS with which I have to be compatible. Adding backward compatibility with nothing may be confusing. =2D-=20 Best Regards, Piotr Zi=EAcik