From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Lawnick Subject: Re: Using the gpio i2c multiplexer driver Date: Wed, 16 Feb 2011 08:07:26 +0100 Message-ID: <4D5B77AE.20307@gmx.de> References: <1297810054.24938.218.camel@groeck-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1297810054.24938.218.camel@groeck-laptop> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: guenter.roeck-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Guenter Roeck said the following: > Hi all, > > I am trying to use the new GPIO based I2C multiplexer. Unfortunately, I > have an initialization problem with it. > > Some time after registering the multiplexer as platform driver, its > probe function is called. Unfortunately, that does not happen in sync > with I2C adapter initialization. The GPIO mux probe function is called > before the parent's (ie the multiplexed I2C adapter) probe function is > called. As a result, the GPIO mux driver does not find its parent i2c > adapter, and the probe function aborts with an error. > > Any idea how I I can fix the problem, ie how I can ensure that the GPIO > mux probe function is only called after its parent I2C adapter is > initialized ? > Well, I assume your GPIO-Mux is registered as an GPIO device? Can't you add it as an I2C-device? This way the right sequence should be kept. HTH -- Michael