On Mon, Jul 07, 2014 at 10:25:54PM +0100, Scott Wood wrote: > On Thu, 2014-07-03 at 23:08 -0500, Jain Priyanka-B32167 wrote: > > > > > -----Original Message----- > > > From: Wood Scott-B07421 > > > Sent: Friday, July 04, 2014 3:40 AM > > > To: Jain Priyanka-B32167 > > > Cc: devicetree@xxxxxxxxxxxxxxx; linuxppc-dev@xxxxxxxxxxxxxxxx; linux- > > > spi@xxxxxxxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx > > > Subject: Re: [PATCH] devicetree/bindings: Add binding for micron n25q512a > > > memory > > > > > > On Thu, 2014-07-03 at 15:42 +0530, Priyanka Jain wrote: > > > > -Micron n25q512a memory is supported by m25p80 driver. > > > > Add compatible field required to support n25q512a in m25p80.txt -Add > > > > micron to the vendor-prefixes.txt file > > > > > > > > Signed-off-by: Priyanka Jain <Priyanka.Jain@xxxxxxxxxxxxx> > > > > --- > > > > Documentation/devicetree/bindings/mtd/m25p80.txt | 1 + > > > > .../devicetree/bindings/vendor-prefixes.txt | 1 + > > > > 2 files changed, 2 insertions(+), 0 deletions(-) > > > > > > Why did you send this to the ppc list but not the spi or mtd lists? > > > > > [Jain Priyanka-B32167] Sorry, I missed that > > > I'm having a hard time following the flow of how these SPI devices get > > > bound -- is the compatible involved at all? I don't see this string > > > (with vendor prefix included) in the driver. I do see a table that > > > contains what looks like device IDs. If the device can report its id, > > > shouldn't we rely on that rather than device tree compatible? > > > > > > -Scott > > [Jain Priyanka-B32167] > > Spi driver has a check to device name corresponding to device-id and compare to what is passed in dts string. > > Please go into more detail. I don't see where the string > "micron,n25q512a" appears in the current kernel. I do see "n25q512a", > but how does that compare successfully with the version of the string > that has a vendor compatible? The spi code has a hack to not require an of_device_id_table: of_register_spi_devices calls of_modalias_node, which for a given "foo,bar" compatible string will set spi->modalias to "bar", by cutting off everything up to and including the comma. Later, spi_match_id can match a device with an spi_device_id->name of "bar". Thus "micron,n25q512a" can match one of the entries already in drivers/mtd/spi-nor/spi-nor.c. This is a real pain when searching around. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
