From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Seidler Subject: Re: MAX1236 with smbus (CS5536 ACB0) Date: Wed, 15 Oct 2008 03:01:56 +0200 Message-ID: References: <48F2A270.8060307@leipzig.freifunk.net> <20081013092548.3d58a320@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20081013092548.3d58a320-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org> 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 Jean Delvare schrieb: > Hi Andreas, > > On Mon, 13 Oct 2008 03:20:48 +0200, Andreas Seidler wrote: >> I want to connect a MAX1236 (ADC) [1] to a I2C/SMBus in a >> PC-Engines/ALIX board to monitor some voltages. >> This board have a AMD geode CPU with an an I2C companion (scx200_acb.c). >> >>[...] >> but i cant access the MAX1236 on slave address 0x34. >> (0x4c is the onbard LM90) > > Maybe it's not wired properly? I can access this ADC wired to a i2c-ibm_iic (build-in IBM PPC_P405) > If it is wired properly, then another possibility is that the MAX1236 > is doing clock stretching beyond what the CS5536 supports... and this is my second problem: i cant read the A/D-converted values from userspace (eg. with i2cget) without spezial code or kernel module? >> Does "I2C no" means the CS5536 is a plain smbus without i2c support? > > Yes and no. It means that the scx200_acb driver runs the CS5536 in > SMBus mode without plain I2C support. But there is also the scx200_i2c > driver (which I would love to see go away in favor of i2c-gpio but > that's another story) which can use the same pins as GPIO to do plain > I2C. Thank you for this info! Know i found "the story" in this thread too (http://lkml.org/lkml/2007/4/14/59) with more infos. now i tested scx200_i2c: root@OpenWrt:/# insmod scx200_gpio scx200_gpio: no SCx200 gpio present root@OpenWrt:/# insmod scx200_i2c scx200_i2c: no SCx200 gpio pins available (i hope thats no problem of the openwrt-distro...) are SCx200 GPIO pins supported by i2c_gpio? (http://lkml.org/lkml/2007/4/19/22) should it work with my Geode/LX800 companion? > If I read the MAX1236 datasheet properly, it uses transactions > which aren't part of the SMBus set, so you may need to use the > scx200_i2c driver, depending on what exactly you need to do with the > MAX1236. I only want to monitor some voltages in my wind-/solarpower system and draw some nice charts - nothing spezial. Regards Andreas _______________________________________________ i2c mailing list i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org http://lists.lm-sensors.org/mailman/listinfo/i2c