All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>

When an erroneous PEB is scheduling for scrubbing, we end up with the
following oops:

[<c0162404>] (prot_queue_del+0x0/0x50) from [<c01635b4>] (ubi_wl_scrub_peb+0xec/0x13c)
[<c01634c8>] (ubi_wl_scrub_peb+0x0/0x13c) from [<c01603bc>] (ubi_eba_read_leb+0x200/0x428)
[<c01601bc>] (ubi_eba_read_leb+0x0/0x428) from [<c015e3c0>] (ubi_leb_read+0xe8/0x138)
[<c015e2d8>] (ubi_leb_read+0x0/0x138) from [<c00d6918>] (ubifs_start_scan+0x7c/0xf4)
[<c00d689c>] (ubifs_start_scan+0x0/0xf4) from [<c00e3650>] (ubifs_recover_leb+0x3c/0x730)
[<c00e3614>] (ubifs_recover_leb+0x0/0x730) from [<c00e444c>] (ubifs_recover_log_leb+0xc8/0x2dc)
[<c00e4384>] (ubifs_recover_log_leb+0x0/0x2dc) from [<c00d7c20>] (ubifs_replay_journal+0xb90/0x13a4)
[<c00d7090>] (ubifs_replay_journal+0x0/0x13a4) from [<c00cdd68>] (ubifs_fill_super+0xb84/0x1054)
[<c00cd1e4>] (ubifs_fill_super+0x0/0x1054) from [<c00ced04>] (ubifs_get_sb+0xc4/0x2ac)
[<c00cec40>] (ubifs_get_sb+0x0/0x2ac) from [<c007f04c>] (vfs_kern_mount+0x58/0x94)
[<c007eff4>] (vfs_kern_mount+0x0/0x94) from [<c007f0e8>] (do_kern_mount+0x40/0xe8)
[<c007f0a8>] (do_kern_mount+0x0/0xe8) from [<c0095628>] (do_new_mount+0x68/0x8c)
[<c00955c0>] (do_new_mount+0x0/0x8c) from [<c00957a8>] (do_mount+0x15c/0x1b8)
[<c009564c>] (do_mount+0x0/0x1b8) from [<c0095890>] (sys_mount+0x8c/0xd4)
[<c0095804>] (sys_mount+0x0/0xd4) from [<c0023c00>] (ret_fast_syscall+0x0/0x2c)
Kernel panic - not syncing: Fatal exception

The problem is that 'ubi_wl_scrub_peb()' does not expect that PEBs may
be in the erroneous tree, which is a bug. This patch fixes the bug
and adds corresponding check to 'ubi_wl_scrub_peb()'. Now it will simply
ignore erroneous PEBs, instead of causing an oops.
Reported-by: NMatthieu CASTET <matthieu.castet@parrot.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

warning: (OPTPROBES && KPROBES && HAVE_OPTPROBES && !PREEMPT && DEBUG_KERNEL ||
MTD_UBI_DEBUG && MTD && SYSFS && MTD_UBI || UBIFS_FS_DEBUG && MISC_FILESYSTEMS &&
UBIFS_FS || LOCKDEP && DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT &&
STACKTRACE_SUPPORT && LOCKDEP_SUPPORT || LATENCYTOP && HAVE_LATENCYTOP_SUPPORT &&
DEBUG_KERNEL && STACKTRACE_SUPPORT && PROC_FS) selects KALLSYMS_ALL
which has unmet direct dependencies (DEBUG_KERNEL && KALLSYMS)
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Commit 0798cea8 "UBI: improve corrupted flash handling"
broke delet-compatible volumes handling - it introduced a limit of 8 eraseblocks which
may be corrupted. And delete-compatible eraseblocks are added to the "corrupted" list,
so if we'd have a large delete-compatible volume, UBI would refuse it.

The fix is to add delete-compatible volumes to the erase list instead. Indeed, they are
corrupted, we just have to erase them.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

list_for_each_entry uses its first argument to move from one element to the
next, so modifying it can break the iteration.  The variable re1 is already
used within the loop as a temporary variable, and is not live here.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
iterator name list_for_each_entry;
expression x,E;
position p1,p2;
@@

list_for_each_entry@p1(x,...) { <... x =@p2 E ...> }

@@
expression x,E;
position r.p1,r.p2;
statement S;
@@

*x =@p2 E
...
list_for_each_entry@p1(x,...) S
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Apparently, the check for a 6-byte ID string introduced by commit
426c457a ("mtd: nand: extend NAND flash
detection to new MLC chips") is NOT sufficient to determine whether or
not a Samsung chip uses their new MLC detection scheme or the old,
standard scheme. This adds a condition to check cell type.
Signed-off-by: NTilman Sauerbeck <tilman@code-monkey.de>
Signed-off-by: NBrian Norris <norris@broadcom.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org

Commit c7b28e25 ("mtd: nand: refactor BB 
marker detection") caused a regression in detection of factory-set bad 
block markers, especially for certain small-page NAND. This fix removes 
some unneeded constraints on using NAND_SMALL_BADBLOCK_POS, making the 
detection code more correct.

This regression can be seen, for example, in Hynix HY27US081G1M and
similar.
Signed-off-by: NBrian Norris <norris@broadcom.com>
Tested-by: NMichael Guntsche <mike@it-loops.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Test on a PXA310 platform with Samsung K9F2G08X0B NAND flash,
with tCH=5 and clk is 156MHz, ns2cycle(5, 156000000) returns -1.

ns2cycle returns negtive value will break NDTR0_tXX macros.

After checking the commit log, I found the problem is introduced by
commit 5b0d4d7c
"[MTD] [NAND] pxa3xx: convert from ns to clock ticks more accurately"

To get num of clock cycles, we use below equation:
num of clock cycles = time (ns) / one clock cycle (ns) + 1
We need to add 1 cycle here because integer division will truncate the result.
It is possible the developers set the Min values in SPEC for timing settings.
Thus the truncate may cause problem, and it is safe to add an extra cycle here.

The various fields in NDTR{01} are in units of clock ticks minus one,
thus we should subtract 1 cycle then.

Thus the correct equation should be:
num of clock cycles = time (ns) / one clock cycle (ns) + 1 - 1
                    = time (ns) / one clock cycle (ns)
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NLei Wen <leiwen@marvell.com>
Acked-by: NEric Miao <eric.y.miao@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org

The drivers for Xilinx' SystemACE and physically mapped MTDs were missing
prototypes for of_address_to_resource(). This patch adds the necessary
headers.
Signed-off-by: NGraeme Smecher <graeme.smecher@mail.mcgill.ca>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

The buswidth for chips of ID 0xD7 is x8, not x16.
This was my previous typo.
Signed-off-by: NBrian Norris <norris@broadcom.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

"plat_id" is always non-NULL here.  There is a zero element on the end
of the m25p_ids[] array and if we hit the end of the loop then plat_id
points to that.

This would lead to a NULL pointer dereference later on in the function.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Acked-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This is just a cleanup, it doesn't fix any bugs.

These functions all check retlen inconsistently and it generates a
warning in Smatch (http://smatch.sf.net).  If retlen were ever NULL it
would cause an oops and the code has been this way since 2006 so someone
would have complained.  Also I looked at other places that implemented
the mtd read and write functions and they dereference retlen without
checking.

I removed the checks.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NMarek Vasut <marek.vasut@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

All hardware initialization will be done in denali_hw_init before
irq handler registered
Change mtd name from "DENALI NAND" to be "denali-nand" since whitespace in
name can cause problems if we use cmdlinepart
Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

In mtd->write, Denali controller will use MODE_11 mode to read
NAND flash status, then return back to MODE_1O mode to do page
write.
Here comes a bug for this kind of using, sometimes controller will
not write data to NAND and just return a good interrupt to tell
driver writing work is done. The data in this page is all 0xff and
this page can not be written again. The reason is unknow.

So read Denali controller register WRITE_PROTECT to get NAND status
instead.
Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

waring: no space for starting a line
Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Fix mtd/nand_base.c kernel-doc warnings and typos.

Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'invert'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:2087): No description found for parameter 'len'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix mtd/nand_base.c kernel-doc warnings and typos.

Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'invert'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:2087): No description found for parameter 'len'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Once the last ECC error was handled, controller will triger an
interrupt. If this interrupt can not be clean on time, controller
may corrupt.
Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

denali_write32() just implements a debug function for iowrite32(),
only print out the write value. Remove this function since it's useless
Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Fixed a pci_resource_len function error;
Changed returning sequence of probe function;
Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

There are three reasons to add this support:
1. users probably know the interface type of their flashs, then probe
can be faster if they give the right type in platform data since wrong
types will not be detected.
2. sometimes, detecting can cause destory to system. For example, for
kernel XIP, detecting can cause NOR enter a mode instructions can not
be fetched right, which will make kernel crash.
3. For a new probe which is not listed in the rom_probe_types, if users
assign it in board files, physmap can still probe it.
Signed-off-by: NBarry Song <21cnbao@gmail.com>
Signed-off-by: NMike Frysinger <vapier.adi@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.

This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.

The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.

Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

As a preparation for the removal of the big kernel
lock in the block layer, this removes the BKL
from the common ioctl handling code, moving it
into every single driver still using it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Removing the redwood mtd mapping driver, because all REDWOOD_[456]
configuration options were removed from the kernel, because they weren't
referenced anywhere.
Signed-off-by: NChristian Dietrich <qy03fugy@stud.informatik.uni-erlangen.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Nand devices with at least 26 bytes of oob data per 512 byte block
can have 8bit ecc on v2 type controllers. This is currently not tested,
but at least this patch puts the ECC_MODE bit into a well defined state.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The v2 controller has a totally different mechanism to check
whether the data we read had ecc errors or not. Implement this.
The mechanism in the v2 controller happens to be identical to
the v3 controller.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This prepares the driver for v3 support. The v3 controller
has a completely different register layout, so add a V1_V2_
namespace to the register defines to avoid confusion with
the v3 regs.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch prepares the driver to add v3 controller support
later. The v3 controller is basically the same controller as v1
and v2, but with a completely different register layout.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We save/restore the value in the buffer anyway, so it makes
no difference whether we use main_area0 or main_area1. So,
we can use main_area0 and remove main_area1 from the driver
which is otherwise unused. Also, clean up the comments in
get_dev_status.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Add the offset to the register base instead. This is done
in preparation for v3 controller support.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NChuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>