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 03:13:23 +0200 Message-ID: References: <48F2A270.8060307@leipzig.freifunk.net> <20081013092548.3d58a320@hyperion.delvare> <48F32CE9.8000109@cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <48F32CE9.8000109-KWPb1pKIrIJaa/9Udqfwiw@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 Jonathan Cameron schrieb: > A driver that should work with this chip is part of the > iio subsystem, so I have a fair bit of familiarity (though > only via 1238 rather than this exact model) I found this subsystem too and its promising, but it depends on RTC with periodic Interupts - and most of embedded hardware lacks of such RTCs. is it possible to attach a ds1307 for this reason? > Done a bit of digging around and my original test code was > > #include > > #include "i2c-dev.h" > > int main(int argc, char* argv[]) > { > > struct i2c_smbus_ioctl_data arg; > union i2c_smbus_data data; > int adaptor_nr=atoi(argv[1]); //check this > char filename[20]; > sprintf(filename,"/dev/i2c-%d",adaptor_nr); > > int file; > if((file = open(filename, O_RDWR))<0) > { > printf("could not open /dev/i2c-%u\n", adaptor_nr); > exit(-1); > } > if(ioctl(file,I2C_SLAVE, 0x34) < 0) > { > printf("could not set slave address \n"); > return -1; > } > > arg.size = I2C_SMBUS_BYTE; > arg.read_write = I2C_SMBUS_WRITE; > arg.command = I2C_SMBUS_BYTE; > > data.byte = 8; > arg.data = &data; > > char buf[2] = {0x79, 0x92}; > write(file, buf,2); > int i; > for(i = 0; i < 20; i++) > { > read(file,buf,2); > > unsigned int a =0; > a = (buf[0] & 0xF) << 8 | buf[1] ; > printf("reading %u\n",a); > > sleep(1); > } > > } > > No idea why I did it without using the smbus_write commands > though. The iio driver is i2c_transfers I'm afraid. > > as for i2c detect, I've just blugeoned it into building for > the pxa271 board I'm using and it picks up a max1239 just fine. can i access the ringbuffer of this driver via sysfs or how userspace side should work? Regards Andreas _______________________________________________ i2c mailing list i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org http://lists.lm-sensors.org/mailman/listinfo/i2c