Re: [U-Boot-Users] soft_i2c and ds1307 with tqm823l

Wolfgang Denk wrote:
[ snip ]

quoted

Ok, well I've successfully compiled with CONFIG_HARD_I2C and have
communicated with my clock, so that is good. Next up is transferring the
date in u-boot to linux, but I'm sure that will be documented somewhere.

You don't "transfer" the daye. Linux will pick it  up  itself  (which
requires an RTC driver and eventually some modifications).

Let me check that I understand: As far as I can see the u-boot realtime
clock drivers just allow you to set and read the time from the u-boot
command line; a useful utility. If linux is to read the time from the
realtime clock it must have a realtime clock driver of its own; there's
no way that u-boot can pass the time to linux at boot time? (Of course,
this would be fraught with difficulties, because depending on how fast
your cpu boots linux, a different amount of time would elapse before
linux could actually do something with the passed date stamp).

So, next up for me is to write a linux driver for the ds1307. I was
actually in the middle of that before getting sidetracked by the u-boot
rtc code. However, the u-boot code has enabled me to hardware debug my
realtime clock circuit, so that was very useful.  Has anyone written a
linux driver for the ds1307 or similar? (I'm cross posting to the
linuxppc-embedded list to ask this question).

quoted

As for CONFIG_SOFT_I2C; Attached (really this time) is a diff between
the original u-boot-0.4.0/include/configs/TQM823L.h and the one that I
have altered. The compile of soft_i2c.c fails with the following error
messages:

That's because you did  not  define  the  required  macros  (see  for
example the configuration in lwmon.h).

Right, so it's not the case that you just #define CONFIG_SOFT_I2C; you
have to correctly define the macros. I shall do some work on the readme
and post a diff later on. Thanks for the pointers.

best,

Seb


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