2008-04-10 22:02:56     where is /dev/i2c-? urgent

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2008-04-10 22:02:56     where is /dev/i2c-? urgent

Jesse Fish (UNITED STATES)

Message: 54059    I have had a hellish ordeal over the past 2 days trying to download the kernel and then the toolchain and compile it. SVNing took 5 hours and the toolchain take 12 hours yes 12 to compile on my computer. It freeze up on GCC for a long time. then after it compiled it didn't even generate the output or build folders and i couldn't use anything that had been built. Also, it somewhat broke my computer in that I have been trying to delete an old toolchain and it is at full cpu and has taken over an hour and shows no improvement...

 

Anyway, I went back to the default provided kernel 08r1. I have a 357 ezkit board. I want I2C communication by read and write. I know how to program that no problem. My problem is when i try opening the /dev/i2c-# file it doesn't exist in the default kernel. I find this confusing because lot and lots of forum posts seem to suggest that people using similar code to me can use an 07 kernel and they have a /dev/i2c-# file. I have checked my /dev/ directory on the blackfin and it has a lot of ram things and other standard dev files but no i2c stuff . Is there a provided kernel file that has this in the file system. I would try to build my own except that I just spent the last 24 hours trying to build the toolchain and now i might be spending another day trying to delete the toolchain source. The rms file for the toolchain didnt work either... I had a friend compile a copy of the toolchain so I could compile things earlier but he wanted me to build my own and well.. you can see how its been.

 

I really would like i2c communication in the next day. Help would be greatly appreciated.

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2008-04-10 22:16:16     Re: where is /dev/i2c-? urgent

Mike Frysinger (UNITED STATES)

Message: 54061    with 2008R1, device nodes are only created when the device drivers are loaded.  if you dont load the required drivers, you dont get device nodes.  the i2c dev interface requires the i2c dev driver as well as an i2c bus driver.

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2008-04-10 22:48:15     Re: where is /dev/i2c-? urgent

Jesse Fish (UNITED STATES)

Message: 54063    Aren't those drivers compiled into the default kernel?

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2008-04-10 22:54:39     Re: where is /dev/i2c-? urgent

Mike Frysinger (UNITED STATES)

Message: 54064    you can see the default kernel config at linux-2.6.x/arch/blackfin/configs/

 

the i2c stuff are all modules.  you need to load them.

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2008-04-11 02:11:21     Re: where is /dev/i2c-? urgent

Jesse Fish (UNITED STATES)

Message: 54070    ok I got a friend with a working toolchain to help me out. We compiled an image with these i2c configs

 

<M> I2C support

<M> I2C device interface

I2C Algorithms --> (no one selected)

I2C Hardware Bus support -->

< > Generic Blackfin .....

BFIN i2C SDA/SCL

<M> Blackfin TWI I2C support

<400> TWI clock (kHZ)

< > Parallel port adapter (light)

< > I2C/SMBus Test Stub

< > PCA9564 on an ISA bus

 

 

is that what I needed to do to load the modules?  Because we still don't have anything in the dev/ for i2c. Or do I load something onto the blackfin after the kernel is in one piece and if so what and how?

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2008-04-11 02:27:41     Re: where is /dev/i2c-? urgent

Mike Frysinger (UNITED STATES)

Message: 54071    you've compiled things as modules which means you then need to load them

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2008-04-11 02:56:59     Re: where is /dev/i2c-? urgent

Jesse Fish (UNITED STATES)

Message: 54072    ok, my friend helped me figure out the module loading. the wiki should be improved on that for the people who have to use these and are only novice linux users. Thanks for your help though!

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2008-04-13 19:43:56     Re: where is /dev/i2c-? urgent

Robin Getz (UNITED STATES)

Message: 54158    Jesse:

 

I'm not sure how much more we can add? Did you find:

 

http://docs.blackfin.uclinux.org/doku.php?id=a_simple_module_example#using_the_module

 

-Robin

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