Re: /proc/bus/i2c is missing

From: Karel Kulhavy
Date: Fri Nov 12 2004 - 09:57:36 EST


On Fri, Nov 12, 2004 at 09:41:47AM -0500, Piszcz, Justin Michael wrote:
> Ah, the documentation is outdated; I no longer have /proc/bus/i2c
> either. You may need to update the other software that used
> /proc/bus/i2c, as it should now use /sys/bus/i2c.
>
> You are correct, <*> I2C support should encompass the i2c_core.
>
> In addition, you may want to install lm_sensors and run the
> sensors-detect script, which will help detect all the required modules
> necessary for your hardware.
>
> Curious, what are you trying to get working with I2C that involves the
> parallel port?

A free technology hardware i2c <-> parport adaptor powered from the parallel
port featuring optical isolation.

Now I have (hopefully - according to some measurements) working airwire
prototype and a known working other board with pcf8591 chip that measures
temperature.

As soon as the adaptor is verified to run flawlessly, it will be redesigned
into a PCB and the result published under GPL in the same style as Ronja
Twister http://ronja.twibright.com/twister/index.php

I have already written the driver for it (added type=6 into i2c-parport.c and
extended the struct adapter_parm .init entry with .init2 and .init3 because the
hardware requires lines d0-d7, init and /autofd to be set to electrical H
simultaneously for the electronics to work) and now I am trying to make it
find the pcf8591 chip connected to it and read some data.

Cl<
>
> -----Original Message-----
> From: Karel Kulhavy [mailto:clock@xxxxxxxxxxxxx]
> Sent: Friday, November 12, 2004 9:37 AM
> To: Piszcz, Justin Michael
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: /proc/bus/i2c is missing
>
> On Fri, Nov 12, 2004 at 09:22:46AM -0500, Piszcz, Justin Michael wrote:
> > You need the core i2c modules loaded.
>
> I have "<*> I2C support" and "<*> I2C device interface" switched on in
> make
> menuconfig (non-modular). I skimmed through the whole I2C support
> submenu
> and didn't find any i2c core. Just i2c core debugging messages, but it
> isn't
> probably what you mean.
>
> Which option in make menuconfig is i2c_core?
>
> And btw I found this:
> root@oberon:/usr/src/linux-2.6.8.1-patched/drivers/i2c/busses# find
> /sys/bus/i2c/sys/bus/i2c
> /sys/bus/i2c/drivers
> /sys/bus/i2c/drivers/pcf8591
> /sys/bus/i2c/drivers/lm85
> /sys/bus/i2c/drivers/lm85/0-002e
> /sys/bus/i2c/drivers/eeprom
> /sys/bus/i2c/drivers/eeprom/0-0052
> /sys/bus/i2c/drivers/eeprom/0-0050
> /sys/bus/i2c/drivers/dev_driver
> /sys/bus/i2c/drivers/i2c_adapter
> /sys/bus/i2c/devices
> /sys/bus/i2c/devices/0-002e
> /sys/bus/i2c/devices/0-0052
> /sys/bus/i2c/devices/0-0050
>
> Isn't it what the documentation talks about as /proc/bus/i2c? Or is it
> something different?
>
> Cl<
> >
> > $ lsmod
> > Module Size Used by
> > adm1021 12092 0
> > i2c_piix4 5648 0
> > i2c_sensor 2912 1 adm1021
> > i2c_dev 7776 0
> > i2c_core 19312 4 adm1021,i2c_piix4,i2c_sensor,i2c_dev
> >
> >
> > -----Original Message-----
> > From: linux-kernel-owner@xxxxxxxxxxxxxxx
> > [mailto:linux-kernel-owner@xxxxxxxxxxxxxxx] On Behalf Of Karel Kulhavy
> > Sent: Friday, November 12, 2004 9:12 AM
> > To: linux-kernel@xxxxxxxxxxxxxxx
> > Subject: /proc/bus/i2c is missing
> >
> > Hello
> >
> > linux 2.6.8.1
> >
> > I insmoded i2c-parport and pcf8591 modules and i2c-1 appeared in my
> /dev
> > (previously, only i2c-0 was there):
> >
> > clock@oberon:~$ ls /dev/i2*
> > /dev/i2c-0 /dev/i2c-1
> >
> > /dev/i2c:
> > 0 1
> >
> > /usr/src/linux/Documentation/i2c says "You can
> > examine /proc/bus/i2c to see what number corresponds to which
> adapter."
> > I don't have any /proc/i2c:
> >
> > clock@oberon:~$ ls /proc/i2c
> > ls: /proc/i2c: No such file or directory
> >
> > However, I have /proc:
> > clock@oberon:~$ ls /proc
> > devices mtrr
> > diskstats net
> > dma partitions
> > driver pci
> > execdomains scsi
> > filesystems self
> > fs slabinfo
> > ide stat
> > interrupts swaps
> > [...] iomem sys
> > ioports sysrq-trigger
> > irq sysvipc
> > kallsyms tty
> > kcore uptime
> > kmsg version
> > loadavg vmstat
> > locks
> > buddyinfo mdstat
> > bus meminfo
> > cmdline misc
> > config.gz modules
> > cpuinfo mounts
> >
> > How can I make /proc/i2c appear?
> >
> > Cl<
> > -
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