[U-Boot-Users] PATCH: Support for multiple I2C controllers + new command structure

Ben Warren bwarren at qstreams.com
Mon May 22 19:25:54 CEST 2006


Let's try this again - attached is a patch which provides command
support for multiple I2C devices in U-Boot. This isn't meant as a final
submission, more as a design review.  The features:

1. Include new 'i2c' command (based on USB implementation) using
CONFIG_I2C_CMD_TREE.  Note - this should probably be a bit in
CONFIG_COMMANDS, but right now I'm more interested in feedback for the
command structure.

2. Allow multiple buses by defining CONFIG_I2C_MULTI_BUS.  Note that
this is only available under the new 'i2c' command mentioned in bullet

3. Allow by-passing of devices when probing a bus by defining
CFG_I2C_MULTI_NOPROBES.  This array contains a list for each bus, where
lists are delimited by 0xff.  I'm sticking with this implementation for
now because I can't come up with anything better. 

Not implemented yet:
- support for 10-bit addresses
- integration of new command into CONFIG_COMMANDS
- Different approach for no-probe list, as requested by Wolfgang Denk.

        Added new 'i2c' master command for all I2C interaction.  This is
conditionally compiled with CONFIG_I2C_CMD_TREE.  New commands added for
setting I2C bus speed as well as changing the active bus if the board
has more than one bus (conditionally compiled with
CONFIG_I2C_MULTI_BUS).  Added a list of devices to ignore when probing
the buses when more than one bus is present.

Please have a look and let me know what you think.  Any comments on
style as well as substance are welcomed.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: I2C_CMD.patch
Type: text/x-patch
Size: 7272 bytes
Desc: not available
Url : http://lists.denx.de/pipermail/u-boot/attachments/20060522/6ebe783c/attachment.bin 

More information about the U-Boot mailing list