This enables ioctl(MEMISLOCKED). Status can now be reported in the
mtdinfo or flash_lock utilities found in mtd-utils.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This code was a bit sloppy, would produce a lot of copy-and-paste, and
did not always provide a sensible interface:

 * It didn't validate the length for LOCK and the offset for UNLOCK, so
   we were essentially discarding half of the user-supplied data and
   assuming what they wanted to lock/unlock
 * It didn't do very good error checking
 * It didn't make use of the fact that this operation works on
   power-of-two dimensions

So, rewrite this to do proper bit arithmetic rather than a bunch of
hard-coded condition tables. Now we have:

 * More comments on how this was derived
 * Notes on what is (and isn't) supported
 * A more exendible function, so we could add support for other
   protection ranges
 * More accurate locking - e.g., suppose the top quadrant is locked (75%
   to 100%); then in the following cases, case (a) will succeed but (b)
   will not (return -EINVAL):
     (a) user requests lock 3rd quadrant (50% to 75%)
     (b) user requests lock 3rd quadrant, minus a few blocks (e.g., 50%
         to 73%)
   Case (b) *should* fail, since we'd have to lock blocks that weren't
   requested. But the old implementation didn't know the difference and
   would lock the entire second half (50% to 100%)

This refactoring work will also help enable the addition of
mtd_is_locked() support and potentially the support of bottom boot
protection (TB=1).
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

I got the names of these fields wrong.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

No functional change, just cosmetic.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

These are often similar for CFI (parallel NOR) and for SPI NOR, but they
aren't always the same, for various reasons (different namespaces,
company acquisitions and renames, etc.). And some don't have CFI_MFR_*
entries at all.

So let's make a proper place to list the SPI NOR IDs, with all the SPI
NOR specific assumptions and comments.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

These status bits use different ways of representing similar integer
constants -- some are decimal, some are hex. Make them more consistent.

At the same time, impose my own preference, since IMO it's clearer what
these are when using the BIT() macro.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

We use BIT() in the header. No real problem for now, but it's better to
be accurate.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The ->read_xxx() methods are all passed the page number the NAND controller
is supposed to read, but ->write_xxx() do not have such a parameter.

This is a problem if we want to properly implement data
scrambling/randomization in order to mitigate MLC sensibility to repeated
pattern: to prevent bitflips in adjacent pages in the same block we need
to avoid repeating the same pattern at the same offset in those pages,
hence the randomizer/scrambler engine need to be passed the page value
in order to adapt its seed accordingly.

Moreover, adding the page parameter to the ->write_xxx() methods add some
consistency to the current API.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
CC: Josh Wu <josh.wu@atmel.com>
CC: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Huang Shijie <shijie.huang@arm.com>
CC: Stefan Agner <stefan@agner.ch>
CC: devel@driverdev.osuosl.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Owner is automatically set by mtdcore. Make use of that.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where mtd parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where mtd parent device symlinks aren't shown in sysfs.

While at it, take advantage of the default owner and name values set by
mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Owner and name are automatically set by mtdcore. Make use of that.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Make sure the device structure is properly shown in sysfs by properly
filling in dev.parent.

While at it, make use of the default owner and name values set by
mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Owner is automatically set by mtdcore. Make use of that.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Owner is automatically set by mtdcore. Make use of that.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Owner is automatically set by mtdcore. Make use of that.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where mtd parent device symlinks aren't shown in sysfs.

While at it, take advantage of the default owner and name values set by
mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Owner is automatically set by mtdcore. Make use of that.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Owner is automatically set by mtdcore. Make use of that.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner and name set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Owner is automatically set by mtdcore. Make use of that.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix a bug where parent device symlinks aren't shown in sysfs.

While at it, make use of the default owner set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>