commit c6b570d97c0e77f570bb6b2ed30d372b2b1e9aae upstream.

This patch fixes a NULL pointer dereference when enabling regmap event
tracing in the presence of a syscon regmap, introduced by commit bdb0066df96e
("mfd: syscon: Decouple syscon interface from platform devices").
That patch introduced syscon regmaps that have their dev field set to NULL.
The regmap trace events expect it to point to a valid struct device and feed
it to dev_name():

  $ echo 1 > /sys/kernel/debug/tracing/events/regmap/enable

  Unable to handle kernel NULL pointer dereference at virtual address 0000002c
  pgd = 80004000
  [0000002c] *pgd=00000000
  Internal error: Oops: 17 [#1] SMP ARM
  Modules linked in: coda videobuf2_vmalloc
  CPU: 0 PID: 304 Comm: kworker/0:2 Not tainted 4.0.0-rc2+ #9197
  Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
  Workqueue: events_freezable thermal_zone_device_check
  task: 9f25a200 ti: 9f1ee000 task.ti: 9f1ee000
  PC is at ftrace_raw_event_regmap_block+0x3c/0xe4
  LR is at _regmap_raw_read+0x1bc/0x1cc
  pc : [<803636e8>]    lr : [<80365f2c>]    psr: 600f0093
  sp : 9f1efd78  ip : 9f1efdb8  fp : 9f1efdb4
  r10: 00000004  r9 : 00000001  r8 : 00000001
  r7 : 00000180  r6 : 00000000  r5 : 9f00e3c0  r4 : 00000003
  r3 : 00000001  r2 : 00000180  r1 : 00000000  r0 : 9f00e3c0
  Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
  Control: 10c5387d  Table: 2d91004a  DAC: 00000015
  Process kworker/0:2 (pid: 304, stack limit = 0x9f1ee210)
  Stack: (0x9f1efd78 to 0x9f1f0000)
  fd60:                                                       9f1efda4 9f1efd88
  fd80: 800708c0 805f9510 80927140 800f0013 9f1fc800 9eb2f490 00000000 00000180
  fda0: 808e3840 00000001 9f1efdfc 9f1efdb8 80365f2c 803636b8 805f8958 800708e0
  fdc0: a00f0013 803636ac 9f16de00 00000180 80927140 9f1fc800 9f1fc800 9f1efe6c
  fde0: 9f1efe6c 9f732400 00000000 00000000 9f1efe1c 9f1efe00 80365f70 80365d7c
  fe00: 80365f3c 9f1fc800 9f1fc800 00000180 9f1efe44 9f1efe20 803656a4 80365f48
  fe20: 9f1fc800 00000180 9f1efe6c 9f1efe6c 9f732400 00000000 9f1efe64 9f1efe48
  fe40: 803657bc 80365634 00000001 9e95f910 9f1fc800 9f1efeb4 9f1efe8c 9f1efe68
  fe60: 80452ac0 80365778 9f1efe8c 9f1efe78 9e93d400 9e93d5e8 9f1efeb4 9f72ef40
  fe80: 9f1efeac 9f1efe90 8044e11c 80452998 8045298c 9e93d608 9e93d400 808e1978
  fea0: 9f1efecc 9f1efeb0 8044fd14 8044e0d0 ffffffff 9f25a200 9e93d608 9e481380
  fec0: 9f1efedc 9f1efed0 8044fde8 8044fcec 9f1eff1c 9f1efee0 80038d50 8044fdd8
  fee0: 9f1ee020 9f72ef40 9e481398 00000000 00000008 9f72ef54 9f1ee020 9f72ef40
  ff00: 9e481398 9e481380 00000008 9f72ef40 9f1eff5c 9f1eff20 80039754 80038bfc
  ff20: 00000000 9e481380 80894100 808e1662 00000000 9e4f2ec0 00000000 9e481380
  ff40: 800396f8 00000000 00000000 00000000 9f1effac 9f1eff60 8003e020 80039704
  ff60: ffffffff 00000000 ffffffff 9e481380 00000000 00000000 9f1eff78 9f1eff78
  ff80: 00000000 00000000 9f1eff88 9f1eff88 9e4f2ec0 8003df30 00000000 00000000
  ffa0: 00000000 9f1effb0 8000eb60 8003df3c 00000000 00000000 00000000 00000000
  ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
  ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff
  Backtrace:
  [<803636ac>] (ftrace_raw_event_regmap_block) from [<80365f2c>] (_regmap_raw_read+0x1bc/0x1cc)
   r9:00000001 r8:808e3840 r7:00000180 r6:00000000 r5:9eb2f490 r4:9f1fc800
  [<80365d70>] (_regmap_raw_read) from [<80365f70>] (_regmap_bus_read+0x34/0x6c)
   r10:00000000 r9:00000000 r8:9f732400 r7:9f1efe6c r6:9f1efe6c r5:9f1fc800
   r4:9f1fc800
  [<80365f3c>] (_regmap_bus_read) from [<803656a4>] (_regmap_read+0x7c/0x144)
   r6:00000180 r5:9f1fc800 r4:9f1fc800 r3:80365f3c
  [<80365628>] (_regmap_read) from [<803657bc>] (regmap_read+0x50/0x70)
   r9:00000000 r8:9f732400 r7:9f1efe6c r6:9f1efe6c r5:00000180 r4:9f1fc800
  [<8036576c>] (regmap_read) from [<80452ac0>] (imx_get_temp+0x134/0x1a4)
   r6:9f1efeb4 r5:9f1fc800 r4:9e95f910 r3:00000001
  [<8045298c>] (imx_get_temp) from [<8044e11c>] (thermal_zone_get_temp+0x58/0x74)
   r7:9f72ef40 r6:9f1efeb4 r5:9e93d5e8 r4:9e93d400
  [<8044e0c4>] (thermal_zone_get_temp) from [<8044fd14>] (thermal_zone_device_update+0x34/0xec)
   r6:808e1978 r5:9e93d400 r4:9e93d608 r3:8045298c
  [<8044fce0>] (thermal_zone_device_update) from [<8044fde8>] (thermal_zone_device_check+0x1c/0x20)
   r5:9e481380 r4:9e93d608
  [<8044fdcc>] (thermal_zone_device_check) from [<80038d50>] (process_one_work+0x160/0x3d4)
  [<80038bf0>] (process_one_work) from [<80039754>] (worker_thread+0x5c/0x4f4)
   r10:9f72ef40 r9:00000008 r8:9e481380 r7:9e481398 r6:9f72ef40 r5:9f1ee020
   r4:9f72ef54
  [<800396f8>] (worker_thread) from [<8003e020>] (kthread+0xf0/0x108)
   r10:00000000 r9:00000000 r8:00000000 r7:800396f8 r6:9e481380 r5:00000000
   r4:9e4f2ec0
  [<8003df30>] (kthread) from [<8000eb60>] (ret_from_fork+0x14/0x34)
   r7:00000000 r6:00000000 r5:8003df30 r4:9e4f2ec0
  Code: e3140040 1a00001a e3140020 1a000016 (e596002c)
  ---[ end trace 193c15c2494ec960 ]---

Fixes: bdb0066df96e (mfd: syscon: Decouple syscon interface from platform devices)
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

this patch change struct regmap->mutex and struct regmap->spinlock
as an union, because these 2 members are only used one of them,
we change it to shrink the struct size.

Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Commit 6cfec04bcc05 ("regmap: Separate regmap dev initialization") moved the
regmap debugfs initialization after regcache initialization. This means
that the regmap debugfs directory is not created yet when the cache
initialization runs and so any debugfs files registered by the regcache are
created in the debugfs root directory rather than the debugfs directory of
the regmap instance. Fix this by adding a separate callback for the
regcache debugfs initialization which will be called after the parent
debugfs entry has been created.

Fixes: 6cfec04bcc05 (regmap: Separate regmap dev initialization)
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

This is the implementation of regmap_multi_reg_write()

There is a new capability 'can_multi_write' that device drivers
must set in order to use this multi reg write mode.

This replaces the first definition, which just defined the API.

Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Rather than passing a flag around through the entire call stack store it
in the regmap struct and read it when required. This minimises the
visibility of the feature through the API, minimising the code updates
needed to use it more widely.

Signed-off-by: Mark Brown <broonie@linaro.org>

Rather than allocating and deallocating the structures used to manage async
transfers each time we do one keep the structures around as long as the
regmap is around. This should provide a small performance improvement.

Signed-off-by: Mark Brown <broonie@linaro.org>

Current Linux kernel is supporting regmap_field method
and it is very useful feature.
It needs one regmap_filed for one register access.

OTOH, there is multi port device which
has many same registers in the market.
The difference for each register access is
only its address offset.

Current API needs many regmap_field for such device,
but it is not good.
This patch adds new regmap_fileds API which can care
about multi port/offset access via regmap.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

With devices which have a dense and small register map but placed at a large
offset the global cache_present bitmap imposes a huge memory overhead. Making
the cache_present per rbtree node avoids the issue and easily reduces the memory
footprint by a factor of ten. For devices with a more sparse map or without a
large base register offset the memory usage might increase slightly by a few
bytes, but not significantly. E.g. for a device which has ~50 registers at
offset 0x4000 the memory footprint of the register cache goes down form 2496
bytes to 175 bytes.

Moving the bitmap to a per node basis means that the handling of the bitmap is
now cache implementation specific and can no longer be managed by the core. The
regcache_sync_block() function is extended by a additional parameter so that the
cache implementation can tell the core which registers in the block are set and
which are not. The parameter is optional and if NULL the core assumes that all
registers are set. The rbtree cache also needs to implement its own drop
callback instead of relying on the core to handle this.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>