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From: Scott Wood <scottwood@freescale.com>
To: Timur Tabi <timur@freescale.com>
Cc: linuxppc-dev@ozlabs.org, kumar.gala@freescale.com
Subject: Re: [PATCH] i2c-mpc: use the cell-index property to enumerate the I2C adapters
Date: Thu, 1 Dec 2011 12:41:40 -0600	[thread overview]
Message-ID: <4ED7CA64.2080503@freescale.com> (raw)
In-Reply-To: <1322760781-31226-1-git-send-email-timur@freescale.com>

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

  reply	other threads:[~2011-12-01 18:41 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-01 17:33 [PATCH] i2c-mpc: use the cell-index property to enumerate the I2C adapters Timur Tabi
2011-12-01 18:41 ` Scott Wood [this message]
2011-12-01 20:54   ` Timur Tabi
2011-12-01 21:29     ` Scott Wood
2011-12-01 21:46       ` Timur Tabi
2011-12-01 21:52         ` Scott Wood
2011-12-01 21:55           ` Grant Likely
2011-12-01 21:59             ` Timur Tabi
2011-12-01 21:59           ` Timur Tabi
2011-12-01 22:05             ` Scott Wood
2011-12-01 22:10               ` Timur Tabi

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