This file lists the register ranges in the register map.  The condition
to split the range is based on whether the block is readable or not.

Ensure that we lock the `debugfs_off_cache' list whenever we access
and modify the list.  There is a possible race otherwise between the
read() operations of the `registers' file and the `range' file.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We don't need to use any of the file position information
to calculate the base and max register of each block.  Just
use the counter directly.

Set `i = base' at the top to avoid GCC flow analysis bugs.  The
value of `i' can never be undefined or 0 in the if (c) { ... }.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

In preparation to support the regmap debugfs ranges functionality
factor this code out to a separate function.  We'll need to ensure
that the value has been correctly calculated from two separate places
in the code.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Optimize this so that we can better guess where to start scanning
from.  We know the length of the register field format, therefore
given the file pointer position align to the nearest register
field and scan from there onwards.  We round down in this calculation
and we let the rest of the code figure out where to start scanning
from.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We are keeping track of the maximum register as well, this will make
things easier for us in sharing this code with the code implementing
the register ranges functionality.  It also simplifies a bit the
calculations when looking for the relevant block:offset from within
the cache.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

At the moment, if the length of the register field format is
N bytes, we can only get anything meaningful back to userspace
by providing a buffer that is N + 2 bytes large.  Fix this
so we that we only need to provide a buffer of N bytes.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Gcc warns about the case where regmap_read_debugfs tries to walk an
empty map->debugfs_off_cache list, which would results in uninitialized
variable getting returned, if we hadn't checked the same condition
just before that.

After an originally suggested inferior patch from Arnd Bergmann,
this is the solution that Russell King came up with, sidestepping
the problem by merging the error case for an empty list with the
normal path.

Without this patch, building mxs_defconfig results in:

drivers/base/regmap/regmap-debugfs.c: In function 'regmap_read_debugfs':
drivers/base/regmap/regmap-debugfs.c:147:9: : warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
Reported-by: NVincent Stehle <v-stehle@ti.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Fix up all callers as they were before, with make one change: an
unsigned module taints the kernel, but doesn't turn off lockdep.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

We don't want to bomb out early if we failed to get the cache any more,
just soldier on instead and we won't get confused and always return the
first block.

Reported-by: Philipp Zabel <p.zabel@pengutronix.de
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This should never happen in the real world.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Rather than trying to soldier on with a partially allocated cache just
throw the cache away and pretend we don't have one in case we can get a
full cache next time around.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Check for the block we were asked to start from, not the position we're
in.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Return the start of the last block we tried to read rather than a position,
and also make sure we update the byte position while we're at it.  Without
this reads that go into nonexistant areas get confused.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Avoid doing a linear scan of the entire register map for each read() of
the debugfs register dump by recording the offsets where valid registers
exist when we first read the registers file. This assumes the set of
valid registers never changes, if this is not the case invalidation of
the cache will be required.

This could be further improved for large blocks of contiguous registers
by calculating the register we will read from within the block - currently
we do a linear scan of the block. An rbtree may also be worthwhile.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

In preparation for doing things a bit more quickly than a linear scan
factor out the initial seek from the debugfs register dump.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If count is less than the size of a register then we may hit integer
wraparound when trying to move backwards to check if we're still in
the buffer. Instead move the position forwards to check if it's still
in the buffer, we are unlikely to be able to allocate a buffer
sufficiently big to overflow here.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org

No point in calculating them every time.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If a register range is named then provide a debugfs file showing the
contents of the range separately.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This will allow the use of the same code for reading register ranges.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

regmap_config.reg_stride is introduced. All extant register addresses
are a multiple of this value. Users of serial-oriented regmap busses will
typically set this to 1. Users of the MMIO regmap bus will typically set
this based on the value size of their registers, in bytes, so 4 for a
32-bit register.

Throughout the regmap code, actual register addresses are used. Wherever
the register address is used to index some array of values, the address
is divided by the stride to determine the index, or vice-versa. Error-
checking is added to all entry-points for register address data to ensure
that register addresses actually satisfy the specified stride. The MMIO
bus ensures that the specified stride is large enough for the register
size.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some devices have multiple separate register regions. Logically, one
regmap would be created per region. One issue that prevents this is that
each instance will attempt to create the same debugfs files. Avoid this
by allowing regmaps to be named, and use the name to construct the
debugfs directory name.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

regmap_config.reg_stride is introduced. All extant register addresses
are a multiple of this value. Users of serial-oriented regmap busses will
typically set this to 1. Users of the MMIO regmap bus will typically set
this based on the value size of their registers, in bytes, so 4 for a
32-bit register.

Throughout the regmap code, actual register addresses are used. Wherever
the register address is used to index some array of values, the address
is divided by the stride to determine the index, or vice-versa. Error-
checking is added to all entry-points for register address data to ensure
that register addresses actually satisfy the specified stride. The MMIO
bus ensures that the specified stride is large enough for the register
size.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some devices have multiple separate register regions. Logically, one
regmap would be created per region. One issue that prevents this is that
each instance will attempt to create the same debugfs files. Avoid this
by allowing regmaps to be named, and use the name to construct the
debugfs directory name.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op.  This leads to a
proliferation of the default_open() implementation across the entire
tree.

Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().

This replacement was done with the following semantic patch:

<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}

@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For files that are actively using linux/device.h, make sure
that they call it out.  This will allow us to clean up some
of the implicit uses of linux/device.h within include/*
without introducing build regressions.

Yes, this was created by "cheating" -- i.e. the headers were
cleaned up, and then the fallout was found and fixed, and then
the two commits were reordered.  This ensures we don't introduce
build regressions into the git history.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Remove unused module.h and/or replace with export.h
as required.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Add a file called 'name' containing the name of the driver.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

To enable writing to the regmap debugfs registers file users will
need to modify the source directly and #define REGMAP_ALLOW_WRITE_DEBUGFS.
The reason for this is that it is dangerous to expose this
functionality in general where clients could potentially be PMICs.

[A couple of minor style updates -- broonie]
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Show all the cache status flags in debugfs if we have a cache.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Off by one in the array iteration.
Reported-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Let userspace know what the access map for the device is. This is helpful
for verifying that the access map is correctly configured and could also
be useful for programs that try to work with the data. File format is:

register: R W V P

where R, W, V and P are 'y' or 'n' showing readable, writable, volatile
and precious respectively.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We're going to be using these in quite a few places so factor out the
readable/writable/volatile/precious checks.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

x86_64 size_t is not an int but the printf format specifier for size_t
should be an int.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Copy over the read parts of the ASoC debugfs implementation into regmap,
allowing users to see what the register values the device has are at
runtime. The implementation, especially the support for seeking, is
mostly due to Dimitris Papastamos' work in ASoC.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>