From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Mack Subject: Re: Need help on selecting one (and only one) i2c bus Date: Wed, 11 Mar 2009 10:47:52 +0100 Message-ID: <20090311094752.GE25824@buzzloop.caiaq.de> References: <000001c9a0c6$bf92af80$b23e81a4@par.st.com> <20090310163044.571e4aff@hyperion.delvare> <20090311101513.271f5464@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20090311101513.271f5464-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: =?utf-8?B?5LyK5rO9?= Cc: Ayman KHAMOUMA , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, pramod gurav , Jean Delvare List-Id: linux-i2c@vger.kernel.org On Wed, 11 Mar 2009 14:27:33 +0800, =E4=BC=8A=E6=B3=BD wrote: = = =20 > > As you said,i2c address 0x00 is not allowed for common i2c slave de= vice,it > > is reserved as broadcast address.Unfortunately,our project has a se= nsor > > cy8c201a0 on i2c-bus,it use 0x00 address. Not true. You need to provide a firmware for that device and this firmware selects the I2C slave address. Read the datasheet again. (page 5): "The I2C address is programmable during configuration. It can be locke= d to prevent accidental change by setting a flag in a config-uration register." > > We met much phone hang problem with i2c,errors such as "waiting for= bus > > free" or "exhausted retries" are all with this sensor. Same reason. Without a firmware, the chips does not have its I2C core set up and hence it's blocking SDA and/or SCL. Daniel