From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Hans J. Koch" Subject: Two start conditions for PCA9554 Date: Tue, 29 Apr 2008 15:11:14 +0200 Message-ID: <20080429131114.GF3195@local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: i2c-bounces-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Errors-To: i2c-bounces-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org To: i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org List-Id: linux-i2c@vger.kernel.org I have an embedded board with a PCA9554 on it. It's an 8-bit IO expander similar to the PCF8574 in mainline. One difference is that when reading from the inputs, you have to do the following: - start condition - send slave address, R/W=0 - send command (0x00 = read input register) - issue another start condition (!) - send slave address, R/W=1 - read data - stop condition Can such a protocol be handled by the i2c subsystem? Thanks, Hans _______________________________________________ i2c mailing list i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org http://lists.lm-sensors.org/mailman/listinfo/i2c