On 05/14/2015 11:32 AM, Brian Norris wrote:
In commit 8ff16cf77ce3 ("Documentation: devicetree: m25p80: add "nor-jedec"
binding"), we added a generic "nor-jedec" binding to catch all
mostly-compatible SPI NOR flash which can be detected via the READ ID
opcode (0x9F). This was discussed and reviewed at the time, however
objections have come up since then as part of this discussion:
http://lkml.kernel.org/g/20150511224646.GJ32500@ld-irv-0074
It seems the parties involved agree that "jedec,spi-nor" does a better
job of capturing the fact that this is SPI-specific, not just any NOR
flash.
This binding was only merged for v4.1-rc1, so it's still OK to change
the naming.
At the same time, let's move the documentation to a better name.
Next up: prune the m25p_ids[] table to the minimal necessary listing, so
we can stop referring to code (drivers/mtd/devices/m25p80.c) from the
documentation.
There's no need to change the code to update the documentation. Simply
paste the list of valid device IDs into the documentation. The binding
documentation needs to be completely standalone anyway. Binding
documentation should never refer to Linux driver code as part of their
definition.
You can never remove the currently-supported device-specific IDs from
the driver, since existing DTs need to continue working forever, even
with future drivers/kernels.
The binding document should also always include a complete list of
supported flash devices. Standard practice is that the DT compatible
property contains a list of compatible values, starting with the
device-specific value, and followed by any generic values. All of those
values should be standardized and specified in the DT documentation,
even if the DT binding is written in such a way that a compliant driver
need only actively match on the generic value. The device-specific
values may not be used today, but are present in case some
device-specific workaround needs to be retro-actively
implemented/enabled, since that needs to happen for existing DTs too.
I'd *really* like to get an 'ack' from a DT maintainer for this, those those
are apparently very hard to come by. And I'd really not like to have to revisit
this again in a few weeks. We have patches getting queued up for 4.2 that are
using the "nor-jedec" binding, and I'd like to nip those in the bud ASAP.
I am not a DT maintainer, but the DT documentation part of this change:
Acked-by: Stephen Warren <swarren@xxxxxxxxxx>
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