From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: Re: Need help on selecting one (and only one) i2c bus Date: Wed, 11 Mar 2009 10:15:13 +0100 Message-ID: <20090311101513.271f5464@hyperion.delvare> References: <000001c9a0c6$bf92af80$b23e81a4@par.st.com> <20090310163044.571e4aff@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: =?UTF-8?B?5LyK5rO9?= Cc: Ayman KHAMOUMA , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, pramod gurav List-Id: linux-i2c@vger.kernel.org On Wed, 11 Mar 2009 14:27:33 +0800, =E4=BC=8A=E6=B3=BD wrote: > hi Jean, >=20 > As you said,i2c address 0x00 is not allowed for common i2c slave devi= ce,it > is reserved as broadcast address.Unfortunately,our project has a sens= or > cy8c201a0 on i2c-bus,it use 0x00 address. >=20 > We met much phone hang problem with i2c,errors such as "waiting for b= us > free" or "exhausted retries" are all with this sensor. >=20 > I guess when master would try to address this senosr,it infact send a > broadcast address,that may cause problem easily,every slave device wo= uld > have a chance to pull down the bus line. >=20 > Now, as the signal show,the ACk signal is too too long in hard-ware,t= hat > cause the the i2c-bus unit busy,which block the other i2c operation. >=20 > I am trying to re-configure i2c-unit as gpio-mode,and set high/low le= vel > manually as a workround. >=20 > Any good suggestion to solve this issue? Yeah, switch to hardware which respects the I2C standard. --=20 Jean Delvare