[U-Boot-Users] PATCH was(ack problem in common/soft_i2c.c)

Andrew Dyer amdyer at gmail.com
Tue Jul 26 20:42:31 CEST 2005

On 7/22/05, Thomas Kastner <thomas.kastner at marekmicro.de> wrote:
> Andrew Dyer wrote:
> > I am working with the soft i2c code on my target and I believe
> > there is a problem in the send_ack() function.
> >
> [snip]
> > In my case changing the order to:
> >
> > I2C_SCL(0);
> > I2C_DELAY;
> I ported U-Boot to the AT91M55800A (ARM7DTMI) which has multi-driver
> capable GPIOs, but didn't want to spend the time to change the I2C code
> and left the ACTIVE/TRISTATE mechanism - and also came across the same
> problem.
> A 24C08 worked fine, but e.g. a ADV7181 would only give me a few
> consecutive reads.
> So yes, I can confirm there is a problem and also that the above
> mentioned fix is OK.

Ok, here's a patch for the queue.


change the sequence of events in soft_i2c.c:send_ack() to keep from
incorrectly generating start/stop conditions on the bus.

Hardware, n.:
        The parts of a computer system that can be kicked.
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