From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: How can I use two command bytes for a block read? Date: Fri, 12 Aug 2011 07:29:51 -0700 Message-ID: <20110812142951.GA23938@ericsson.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: lm-sensors-bounces@lm-sensors.org Errors-To: lm-sensors-bounces@lm-sensors.org To: Wayne Tams Cc: linux-i2c@vger.kernel.org, "lm-sensors@lm-sensors.org" List-Id: linux-i2c@vger.kernel.org On Fri, Aug 12, 2011 at 05:21:15AM -0400, Wayne Tams wrote: > Hi, > > I am having a little bother interfacing with a device that requires two command > bytes for both reads and writes. I can perform a successful write using I2C > writes but I would rather use the user-space i2c_smbus_ functions from > i2c-dev.h. In the i2c-dev documentation (http://lxr.free-electrons.com/source/ > Documentation/i2c/smbus-protocol?v=2.6.35;a=arm#L225) there is a mention of a > two byte command block read but there does not appear to be any supporting > function in i2c-dev.h. Is there a patch available to add this functionality or > could there be another approach? > > Just to clarify I need my smbus read transaction to look like this: > > > > S Addr Wr [A] Comm1 [A] Comm2 [A] S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P > > Thanks > > Wayne Wrong mailing list. Try linux-i2c@vger.kernel.org (copied). As a general hint, eeprom drivers such as drivers/misc/eeprom/at24.c do this; you might want to have a look. Guenter _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors