If the chip was in shutdown mode when the driver was loaded, the first
conversion is ready no more than 35 milli-seconds after the chip was
taken out of shutdown. The driver delay was so far set to 333 ms (HZ / 3),
which is much higher than the maximum time needed by the chip.
Reduce the time to 35 milli-seconds.

Introduce a 'valid' flag to ensure that sensor data is actually read
even if requested less than 333 ms after the driver was loaded.
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

checkpatch rightfully complains that else after return is unnecessary.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Use bool for valid flag and leave it up to the compiler to find
an optimal representation.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Read limit registers only once at startup or after errors to improve
driver performance.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Return both error code and register value as return code from
read functions, and always check for errors.

This reduces code size on x86_64 by more than 1k while at
the same time improving error resiliency.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Since all other cleanup handled with devm_add_action, we can use
devm_hwmon_device_register_with_groups() to register the hwmon
device, and drop the remove function.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Use devm_add_action where possible to simplify error handling and
cleanup on remove.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Convert to use regmap. Leave caching to regmap and drop the register
update function. While this can result in additional read operations
if the temperature register is read continuously, it avoids re-reading
the limit registers and thus overall reduces complexity.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Since we know the chip's update interval, let's make it available
to the user.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

lm75_read_value and lm75_write_value don't really add any value.
Replace with direct smbus access functions.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Use devm_add_action() to register the function to restore the original
chip configuration. Use devm_hwmon_device_register_with_groups()
to register the hwmon device, and drop the remove function as no
longer needed.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

In 2011, commit 774466ad ("hwmon: (jc42) Change detection class")
changed the detection class of these chips to I2C_CLASS_SPD based
on this premise: "makes more sense because these chips always live on
memory modules"

Today these chips have applications beyond memory modules. Examples are
JC42.4 compatible chips such as MCP9804 and MCP9808, but also MCP9805,
which is marked as JC42.4 compliant and suggested for use not only for
DIMMS, but also as generic temperature sensor.

Add I2C_CLASS_HWMON as an additional detection class to allow detection
by hwmon class i2c adapters.
Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
[groeck: Updated description]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

The FSF address can change, so drop it from the driver.
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

By registering a cleanup function with devm_add_action(), we can
simplify the error path in the probe function and drop the remove
function entirely.
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

MCP9808 is not officially compliant to JC-42, similar to MCP9804,
but its registers are compatible to JC-42.
Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

The result of an integer divide by an unsigned is undefined.
This causes unexpected results when writing negative values
into the limit registers.

Maintain the shunt_resistors variables as signed integer to avoid
the problem. Also, for simplicity and ease of use, clamp shunt
resistor value on writes instead of rejecting bad values.

Cc: Andrew F. Davis <afd@ti.com>
Acked-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

trivial fix to spelling mistake in dev_dbg message
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

This allow us to debug how long take each SMM call and how long is system
frozen in SMM handler.
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Some Dell machines (e.g. Dell Precision M3800) have two fans, first with
index=0 and second with index=2. So export also attributes for third fan
device with index=2.
Reported-by: Tolga Cakir <cevelnet@gmail.com>
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Tolga Cakir <cevelnet@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Use ATTRIBUTE_GROUPS macro and devm_hwmon_device_register_with_groups() to
simplify the code a bit.

The update_lock mutex is not used, so remove it.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Use ATTRIBUTE_GROUPS macro and devm_hwmon_device_register_with_groups() to
simplify the code a bit.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Use ATTRIBUTE_GROUPS macro and devm_hwmon_device_register_with_groups() to
simplify the code a bit.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Add more details to the guidelines for submitting patches.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Add support for the the INA3221 26v capable, Triple channel,
Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
with I2C interface.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

This driver implements support for the Sensirion SHT3x-DIS chip,
a humidity and temperature sensor. Temperature is measured
in degrees celsius, relative humidity is expressed as a percentage.
In the sysfs interface, all values are scaled by 1000,
i.e. the value for 31.5 degrees celsius is 31500.
Signed-off-by: Pascal Sachs <pascal.sachs@sensirion.com>
[groeck: Fixed 'Variable length array is used' gcc warning]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
[groeck: Updated subject]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
[groeck: Updated subject]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Pull SCSI fixes from James Bottomley:
 "Two straightforward fixes.

  One is a concurrency issue only affecting SAS connected SATA drives,
  but which could hang the storage subsystem if it triggers (because the
  outstanding command count on error never goes back to zero) and the
  other is a NO_TAG fallout from the switch to hostwide tags which
  causes the system to crash on module insertion (we've checked
  carefully and only the 53c700 family of drivers is vulnerable to this
  issue)"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  53c700: fix BUG on untagged commands
  scsi: fix race between simultaneous decrements of ->host_failed

Merge branch 'for-linus-4.7-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs fixes part 2 from Chris Mason:
 "This has one patch from Omar to bring iterate_shared back to btrfs.

  We have a tree of work we queue up for directory items and it doesn't
  lend itself well to shared access.  While we're cleaning it up, Omar
  has changed things to use an exclusive lock when there are delayed
  items"

* 'for-linus-4.7-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix ->iterate_shared() by upgrading i_rwsem for delayed nodes

Pull btrfs fixes from Chris Mason:
 "I have a two part pull this time because one of the patches Dave
  Sterba collected needed to be against v4.7-rc2 or higher (we used
  rc4).  I try to make my for-linus-xx branch testable on top of the
  last major so we can hand fixes to people on the list more easily, so
  I've split this pull in two.

  This first part has some fixes and two performance improvements that
  we've been testing for some time.

  Josef's two performance fixes are most notable.  The transid tracking
  patch makes a big improvement on pretty much every workload"

* 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: Force stripesize to the value of sectorsize
  btrfs: fix disk_i_size update bug when fallocate() fails
  Btrfs: fix error handling in map_private_extent_buffer
  Btrfs: fix error return code in btrfs_init_test_fs()
  Btrfs: don't do nocow check unless we have to
  btrfs: fix deadlock in delayed_ref_async_start
  Btrfs: track transid for delayed ref flushing

Pull sound fixes from Takashi Iwai:
 "Again pretty calm weeks: we've had only a few trivial / stable
  HD-audio fixes in addition to a possible race fix for snd-dummy driver
  spotted by syzkaller"

* tag 'sound-4.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: dummy: Fix a use-after-free at closing
  ALSA: hda / realtek - add two more Thinkpad IDs (5050,5053) for tpt460 fixup
  ALSA: hda - Fix the headset mic jack detection on Dell machine
  ALSA: hda/tegra: iomem fixups for sparse warnings
  ALSA: hdac_regmap - fix the register access for runtime PM

Pull x86 kprobe fix from Thomas Gleixner:
 "A single fix clearing the TF bit when a fault is single stepped"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kprobes/x86: Clear TF bit in fault on single-stepping

Pull scheduler fixes from Thomas Gleixner:
 "A couple of scheduler fixes:

   - force watchdog reset while processing sysrq-w

   - fix a deadlock when enabling trace events in the scheduler

   - fixes to the throttled next buddy logic

   - fixes for the average accounting (missing serialization and
     underflow handling)

   - allow kernel threads for fallback to online but not active cpus"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Allow kthreads to fall back to online && !active cpus
  sched/fair: Do not announce throttled next buddy in dequeue_task_fair()
  sched/fair: Initialize throttle_count for new task-groups lazily
  sched/fair: Fix cfs_rq avg tracking underflow
  kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while processing sysrq-w
  sched/debug: Fix deadlock when enabling sched events
  sched/fair: Fix post_init_entity_util_avg() serialization

Commit fe742fd4 ("Revert "btrfs: switch to ->iterate_shared()"")
backed out the conversion to ->iterate_shared() for Btrfs because the
delayed inode handling in btrfs_real_readdir() is racy. However, we can
still do readdir in parallel if there are no delayed nodes.

This is a temporary fix which upgrades the shared inode lock to an
exclusive lock only when we have delayed items until we come up with a
more complete solution. While we're here, rename the
btrfs_{get,put}_delayed_items functions to make it very clear that
they're just for readdir.

Tested with xfstests and by doing a parallel kernel build:

	while make tinyconfig && make -j4 && git clean dqfx; do
		:
	done

along with a bunch of parallel finds in another shell:

	while true; do
		for ((i=0; i<4; i++)); do
			find . >/dev/null &
		done
		wait
	done
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

Pull locking fix from Thomas Gleixner:
 "A single fix to address a race in the static key logic"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/static_key: Fix concurrent static_key_slow_inc()

Pull irq fix from Thomas Gleixner:
 "A single fix for the fallout from the conversion of MIPS GIC to irq
  domains"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mips-gic: Fix IRQs in gic_dev_domain

Pull powerpc fixes from Michael Ellerman:
 "mm/radix (Aneesh Kumar K.V):
   - Update to tlb functions ric argument
   - Flush page walk cache when freeing page table
   - Update Radix tree size as per ISA 3.0

  mm/hash (Aneesh Kumar K.V):
   - Use the correct PPP mask when updating HPTE
   - Don't add memory coherence if cache inhibited is set

  eeh (Gavin Shan):
   - Fix invalid cached PE primary bus

  bpf/jit (Naveen N. Rao):
   - Disable classic BPF JIT on ppc64le

  .. and fix faults caused by radix patching of SLB miss handler
  (Michael Ellerman)"

* tag 'powerpc-4.7-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/bpf/jit: Disable classic BPF JIT on ppc64le
  powerpc: Fix faults caused by radix patching of SLB miss handler
  powerpc/eeh: Fix invalid cached PE primary bus
  powerpc/mm/radix: Update Radix tree size as per ISA 3.0
  powerpc/mm/hash: Don't add memory coherence if cache inhibited is set
  powerpc/mm/hash: Use the correct PPP mask when updating HPTE
  powerpc/mm/radix: Flush page walk cache when freeing page table
  powerpc/mm/radix: Update to tlb functions ric argument

Commit b235beea ("Clarify naming of thread info/stack allocators")
breaks the build on some powerpc configs, where THREAD_SIZE < PAGE_SIZE:

  kernel/fork.c:235:2: error: implicit declaration of function 'free_thread_stack'
  kernel/fork.c:355:8: error: assignment from incompatible pointer type
    stack = alloc_thread_stack_node(tsk, node);
    ^

Fix it by renaming free_stack() to free_thread_stack(), and updating the
return type of alloc_thread_stack_node().

Fixes: b235beea ("Clarify naming of thread info/stack allocators")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>