ppc440 and i2c

Wolfgang Denk wd at denx.de
Tue Nov 18 19:09:02 EST 2003

In message <20031118071829.43116.qmail at web40301.mail.yahoo.com> you wrote:
> I am running ppc440 with linux kernel version 2.4

Grrrghh...  You  sent  the  same  message   twice   to   the   (dead)
PPCBoot-Users   list   and   another   time  to  linuxppc-embedded???
Grrrrghhh!!!! Please fix your posting habits.

> >From the i2c bus trace it looks like in this
> situation ppc440 keeps issuing the clock pulses
> until the data line SDL is released by the slave
> but following that the SCL line is held low
> by ppc440 and is never released or set to IDLE?
> Is this the expected behaviour if the SDL is held
> low when the ppc440 comes up.

This is an expected and documented problem. See "doc/I2C_Edge_Conditions" in
the U-Boot / PPCBoot sources.

> Is there anyway I can fix this in the ppcboot code.

Yes. You could back-port the fixes that  went  into  U-Boot.  But  it
probably makes more sense to switch to U-Boot instead.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
A meeting is an event at which the minutes are kept and the hours are

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