Re: [PATCH] i2c-mpc: use the cell-index property to enumerate the I2C adapters

On 12/01/2011 11:33 AM, Timur Tabi wrote:

An I2C device tree node can contain a 'cell-index' property that can be
used to enumerate the I2C devices.  If such a property exists, use it
to specify the I2C adapter number.

Didn't we decide a long time ago that this was a bad idea?

This feature is necessary for the Freescale PowerPC audio drivers (e.g.
on the P1022DS).  The "machine driver" needs to know the adapter number
for each I2C adapter, but it only has access to the device tree.
Previously, the I2C nodes always appeared in cell-index order, so the
dynamic numbering coincided with the cell-index property.  With commit
ab827d97 ("powerpc/85xx: Rework P1022DS device tree"), the I2C nodes are
unintentionally reversed in the device tree, and so the machine driver
guesses the wrong I2C adapter number.

What specifically do you need this number for?  What does it represent?

-Scott