Problem with CPM I2C driver

Problem with CPM I2C driver

[Kim Jørgensen]

Hi.

After solving my hardware problem on custom MPC823E board and I got my LCD
running, thank you for the help.
But I have a new problem: I want to use the I2C bus, but the driver doesn't
seam to work.

I added CPM IIC and IIC/SPI Microcode patch in xconfig. Then I added the
cpm_iic_init function in drivers/char/mem.c so that is would be called at
startup.

When I try to read some data from /dev/i2c0 the driver just hang. I have
added some printk in the iic driver read function, and it seam to hang just
after enabling the i2c controller.
Can anyone help me with this?

The "driver" in arch/ppc/mbxboot seam to work fine on my board.

Is there any other more complete i2c driver available?

---
Kim Jorgensen

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Re: Problem with CPM I2C driver

[Richard Hendricks]

Kim Jørgensen wrote:
>
> Hi.
>
> After solving my hardware problem on custom MPC823E board and I got my LCD
> running, thank you for the help.
> But I have a new problem: I want to use the I2C bus, but the driver doesn't
> seam to work.
>
> I added CPM IIC and IIC/SPI Microcode patch in xconfig. Then I added the
> cpm_iic_init function in drivers/char/mem.c so that is would be called at
> startup.

I assume you are using the microcode patch because you are using
Ethernet?
If your Ethernet is on SCC2 (which it should be), you don't need the
patch unless you are using SPI.

> When I try to read some data from /dev/i2c0 the driver just hang. I have
> added some printk in the iic driver read function, and it seam to hang just
> after enabling the i2c controller.
> Can anyone help me with this?

Are you trying to do any of the CPM Microcontroller commands?  I don't
think you can do the SPI/I2C commands when using the patch.  The uCode
patch itself has been recently updated to address a problem with
high CPM loads, is that the environment you are running in?

> The "driver" in arch/ppc/mbxboot seam to work fine on my board.
>
> Is there any other more complete i2c driver available?
>
> ---
> Kim Jorgensen
>

--
MPC823 Applications Engineering Development
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Re: Problem with CPM I2C driver

[Dan Malek]

Richard Hendricks wrote:

> If your Ethernet is on SCC2 (which it should be), you don't need the
> patch unless you are using SPI.

Right, and further just don't use the microcode patches at all......

The patches seem to cause more problems than they fix, which
isn't necessarily the patches themselves, but a combination of
using the proper patch for the proper silicon revision and proper
driver modifications.  I don't even understand all of the permutations,
I can't get anyone from Motorola to explan all of them, and I simply
have some combinations that work and others that don't.

I dropped those functions there to make sure I don't lose them,
and I doubt they will work on anything other than one spcific
combination I was testing.

The microcode patches don't "fix" anything, since nothing is
really broken.  They simply relocate devices in the parameter RAM
memory space when something like Ethernet spills into a following
memory space.



	-- Dan

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