RE: [PATCH 1/2] [MTD] Add support for RAM ROMmappings in the physmap_of MTD driver.

2008-04-28 Thread Rune Torgersen
Laurent Pinchart wrote:
 Last thing I heard was that the device tree should not encode
 a device's
 expected usage, so memory nodes should not have any
 compatible property that
 would automatically associated them to an MTD driver. I've
 been adviced to
 add platform-specific code to instantiate a platform device manually
 (possibly checking if the required memory node is present in
 the device
 tree). This arguably makes sense, but adds more
 platform-specific code.

So... What good it the device tree at all then, if intended usage should
not be encoded in there.
Most other devices has an intended usage encoded.

Examples would be the FCC's on a Freescale PQ2 chip, where they are
encoded as ethernet controllers. (Thsy could be used as high-speed HDLC
controllers, ATM controllers and other usages), the SCC ports (as
serial, they can be used for syncronous serial and HDLC)

That would also mean if usage would change, the kernel image (and
possiby u-boot) whould have to change, instead of just fixing the device
tree. Argh
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Re: [PATCH 1/2] [MTD] Add support for RAM ROMmappings in the physmap_of MTD driver.

2008-04-28 Thread Scott Wood
On Mon, Apr 28, 2008 at 11:26:15AM -0500, Rune Torgersen wrote:
 Examples would be the FCC's on a Freescale PQ2 chip, where they are
 encoded as ethernet controllers. (Thsy could be used as high-speed HDLC
 controllers, ATM controllers and other usages), the SCC ports (as
 serial, they can be used for syncronous serial and HDLC)

But that choice is made by board-level hardware, not purely by software.

-Scott
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