From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: Re: I2C_SMBUS_WORD Definition Date: Sun, 20 Jan 2008 10:23:35 +0100 Message-ID: <20080120102335.5cc6a936@hyperion.delvare> References: <20080119174950.1f12f3c0@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: 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: Gary Chambers Cc: I2C Mailing List List-Id: linux-i2c@vger.kernel.org Hi Gary, On Sat, 19 Jan 2008 15:55:42 -0500 (EST), Gary Chambers wrote: > > i2c_smbus_read_word_data() does exist, isn't it what you are looking > > for? It corresponds to a "read word" transaction in SMBus terminology. > > i2c_smbus_read_word_data() implies (to me, anyway) a required > data/command in the transaction. That's correct, the "read word" SMBus transaction first writes a "command" byte to the device (typically a register address in the device) before reading two bytes from it. > Some of the devices with which we deal > apparently cannot tolerate this extra 8 bits on the bus when attempting > to read a word from them. The bus analyzer also indicates those extra > bits are present. I'm doing my work through the dev interface, and our > functionality matrix seems to indicate that I cannot use pure I2C. Any > thoughts or insight? Thanks very much! Well, reading two bytes from a device directly doesn't correspond to any SMBus transaction, so if your bus controller doesn't support I2C messaging, I fear that you're pretty much stuck. What adapter is this? And what chip are you trying to talk to? -- Jean Delvare _______________________________________________ i2c mailing list i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org http://lists.lm-sensors.org/mailman/listinfo/i2c