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1,105,074 commits

Author SHA1 Message Date
Mike Snitzer
205649d84c dm: reorder members in mapped_device struct
Improves alignment and groups related members relative to cachelines.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2022-02-21 15:36:21 -05:00
Mike Snitzer
0ab30b4079 dm: eliminate copying of dm_io fields in dm_io_dec_pending
There is no need for dm_io_dec_pending() to copy dm_io fields
anymore now that DM provides its own pending_io counters again.

The race documented in commit d208b89401 ("dm: fix mempool NULL
pointer race when completing IO") no longer exists now that block
core's in_flight counters aren't used to signal all dm_io is
complete.

Also, rename {start,end}_io_acct to dm_{start,end}_io_acct.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2022-02-21 15:36:18 -05:00
Mike Snitzer
0cdb90f0f3 dm stats: fix too short end duration_ns when using precise_timestamps
dm_stats_account_io()'s STAT_PRECISE_TIMESTAMPS support doesn't handle
the fact that with commit b879f915bc ("dm: properly fix redundant
bio-based IO accounting") io->start_time _may_ be in the past (meaning
the start_io_acct() was deferred until later).

Add a new dm_stats_recalc_precise_timestamps() helper that will
set/clear a new 'precise_timestamps' flag in the dm_stats struct based
on whether any configured stats enable STAT_PRECISE_TIMESTAMPS.
And update DM core's alloc_io() to use dm_stats_record_start() to set
stats_aux.duration_ns if stats->precise_timestamps is true.

Also, remove unused 'last_sector' and 'last_rw' members from the
dm_stats struct.

Fixes: b879f915bc ("dm: properly fix redundant bio-based IO accounting")
Cc: stable@vger.kernel.org
Co-developed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2022-02-21 15:35:39 -05:00
Mike Snitzer
8d394bc4ad dm: fix double accounting of flush with data
DM handles a flush with data by first issuing an empty flush and then
once it completes the REQ_PREFLUSH flag is removed and the payload is
issued.  The problem fixed by this commit is that both the empty flush
bio and the data payload will account the full extent of the data
payload.

Fix this by factoring out dm_io_acct() and having it wrap all IO
accounting to set the size of  bio with REQ_PREFLUSH to 0, account the
IO, and then restore the original size.

Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2022-02-21 15:35:25 -05:00
Mike Snitzer
9f6dc63376 dm: interlock pending dm_io and dm_wait_for_bios_completion
Commit d208b89401 ("dm: fix mempool NULL pointer race when
completing IO") didn't go far enough.

When bio_end_io_acct ends the count of in-flight I/Os may reach zero
and the DM device may be suspended. There is a possibility that the
suspend races with dm_stats_account_io.

Fix this by adding percpu "pending_io" counters to track outstanding
dm_io. Move kicking of suspend queue to dm_io_dec_pending(). Also,
rename md_in_flight_bios() to dm_in_flight_bios() and update it to
iterate all pending_io counters.

Fixes: d208b89401 ("dm: fix mempool NULL pointer race when completing IO")
Cc: stable@vger.kernel.org
Co-developed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2022-02-21 15:19:08 -05:00
Jason A. Donenfeld
3191dd5a11 random: clear fast pool, crng, and batches in cpuhp bring up
For the irq randomness fast pool, rather than having to use expensive
atomics, which were visibly the most expensive thing in the entire irq
handler, simply take care of the extreme edge case of resetting count to
zero in the cpuhp online handler, just after workqueues have been
reenabled. This simplifies the code a bit and lets us use vanilla
variables rather than atomics, and performance should be improved.

As well, very early on when the CPU comes up, while interrupts are still
disabled, we clear out the per-cpu crng and its batches, so that it
always starts with fresh randomness.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:21 +01:00
Jason A. Donenfeld
b777c38239 random: pull add_hwgenerator_randomness() declaration into random.h
add_hwgenerator_randomness() is a function implemented and documented
inside of random.c. It is the way that hardware RNGs push data into it.
Therefore, it should be declared in random.h. Otherwise sparse complains
with:

random.c:1137:6: warning: symbol 'add_hwgenerator_randomness' was not declared. Should it be static?

The alternative would be to include hw_random.h into random.c, but that
wouldn't really be good for anything except slowing down compile time.

Cc: Matt Mackall <mpm@selenic.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:21 +01:00
Jason A. Donenfeld
1daf2f3876 random: check for crng_init == 0 in add_device_randomness()
This has no real functional change, as crng_pre_init_inject() (and
before that, crng_slow_init()) always checks for == 0, not >= 2. So
correct the outer unlocked change to reflect that. Before this used
crng_ready(), which was not correct.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:21 +01:00
Jason A. Donenfeld
da792c6d5f random: unify early init crng load accounting
crng_fast_load() and crng_slow_load() have different semantics:

- crng_fast_load() xors and accounts with crng_init_cnt.
- crng_slow_load() hashes and doesn't account.

However add_hwgenerator_randomness() can afford to hash (it's called
from a kthread), and it should account. Additionally, ones that can
afford to hash don't need to take a trylock but can take a normal lock.
So, we combine these into one function, crng_pre_init_inject(), which
allows us to control these in a uniform way. This will make it simpler
later to simplify this all down when the time comes for that.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:17 +01:00
Jason A. Donenfeld
afba0b80b9 random: do not take pool spinlock at boot
Since rand_initialize() is run while interrupts are still off and
nothing else is running, we don't need to repeatedly take and release
the pool spinlock, especially in the RDSEED loop.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:17 +01:00
Jason A. Donenfeld
58340f8e95 random: defer fast pool mixing to worker
On PREEMPT_RT, it's problematic to take spinlocks from hard irq
handlers. We can fix this by deferring to a workqueue the dumping of
the fast pool into the input pool.

We accomplish this with some careful rules on fast_pool->count:

  - When it's incremented to >= 64, we schedule the work.
  - If the top bit is set, we never schedule the work, even if >= 64.
  - The worker is responsible for setting it back to 0 when it's done.

There are two small issues around using workqueues for this purpose that
we work around.

The first issue is that mix_interrupt_randomness() might be migrated to
another CPU during CPU hotplug. This issue is rectified by checking that
it hasn't been migrated (after disabling irqs). If it has been migrated,
then we set the count to zero, so that when the CPU comes online again,
it can requeue the work. As part of this, we switch to using an
atomic_t, so that the increment in the irq handler doesn't wipe out the
zeroing if the CPU comes back online while this worker is running.

The second issue is that, though relatively minor in effect, we probably
want to make sure we get a consistent view of the pool onto the stack,
in case it's interrupted by an irq while reading. To do this, we don't
reenable irqs until after the copy. There are only 18 instructions
between the cli and sti, so this is a pretty tiny window.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Sultan Alsawaf <sultan@kerneltoast.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:17 +01:00
Jason A. Donenfeld
5f75d9f3ba random: rewrite header introductory comment
Now that we've re-documented the various sections, we can remove the
outdated text here and replace it with a high-level overview.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:17 +01:00
Jason A. Donenfeld
0deff3c432 random: group sysctl functions
This pulls all of the sysctl-focused functions into the sixth labeled
section.

No functional changes.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:17 +01:00
Jason A. Donenfeld
a6adf8e7a6 random: group userspace read/write functions
This pulls all of the userspace read/write-focused functions into the
fifth labeled section.

No functional changes.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:17 +01:00
Jason A. Donenfeld
92c653cf14 random: group entropy collection functions
This pulls all of the entropy collection-focused functions into the
fourth labeled section.

No functional changes.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:09 +01:00
Jason A. Donenfeld
a5ed7cb1a7 random: group entropy extraction functions
This pulls all of the entropy extraction-focused functions into the
third labeled section.

No functional changes.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:09 +01:00
Jason A. Donenfeld
3655adc708 random: group crng functions
This pulls all of the crng-focused functions into the second labeled
section.

No functional changes.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:09 +01:00
Jason A. Donenfeld
5f1bb11200 random: group initialization wait functions
This pulls all of the readiness waiting-focused functions into the first
labeled section.

No functional changes.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:04 +01:00
Jason A. Donenfeld
87e7d5abad random: remove whitespace and reorder includes
This is purely cosmetic. Future work involves figuring out which of
these headers we need and which we don't.

Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:04 +01:00
Jason A. Donenfeld
6071a6c0fb random: remove useless header comment
This really adds nothing at all useful.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:04 +01:00
Jason A. Donenfeld
246c03dd89 random: introduce drain_entropy() helper to declutter crng_reseed()
In preparation for separating responsibilities, break out the entropy
count management part of crng_reseed() into its own function.

No functional changes.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Jason A. Donenfeld
b2f408fe40 random: deobfuscate irq u32/u64 contributions
In the irq handler, we fill out 16 bytes differently on 32-bit and
64-bit platforms, and for 32-bit vs 64-bit cycle counters, which doesn't
always correspond with the bitness of the platform. Whether or not you
like this strangeness, it is a matter of fact.  But it might not be a
fact you well realized until now, because the code that loaded the irq
info into 4 32-bit words was quite confusing.  Instead, this commit
makes everything explicit by having separate (compile-time) branches for
32-bit and 64-bit types.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Jason A. Donenfeld
a07fdae346 random: add proper SPDX header
Convert the current license into the SPDX notation of "(GPL-2.0 OR
BSD-3-Clause)". This infers GPL-2.0 from the text "ALTERNATIVELY, this
product may be distributed under the terms of the GNU General Public
License, in which case the provisions of the GPL are required INSTEAD OF
the above restrictions" and it infers BSD-3-Clause from the verbatim
BSD 3 clause license in the file.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Jason A. Donenfeld
14c174633f random: remove unused tracepoints
These explicit tracepoints aren't really used and show sign of aging.
It's work to keep these up to date, and before I attempted to keep them
up to date, they weren't up to date, which indicates that they're not
really used. These days there are better ways of introspecting anyway.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Jason A. Donenfeld
95e6060c20 random: remove ifdef'd out interrupt bench
With tools like kbench9000 giving more finegrained responses, and this
basically never having been used ever since it was initially added,
let's just get rid of this. There *is* still work to be done on the
interrupt handler, but this really isn't the way it's being developed.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Jason A. Donenfeld
0791e8b655 random: tie batched entropy generation to base_crng generation
Now that we have an explicit base_crng generation counter, we don't need
a separate one for batched entropy. Rather, we can just move the
generation forward every time we change crng_init state or update the
base_crng key.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Dominik Brodowski
7191c628fe random: fix locking for crng_init in crng_reseed()
crng_init is protected by primary_crng->lock. Therefore, we need
to hold this lock when increasing crng_init to 2. As we shouldn't
hold this lock for too long, only hold it for those parts which
require protection.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Jason A. Donenfeld
7b5164fb12 random: zero buffer after reading entropy from userspace
This buffer may contain entropic data that shouldn't stick around longer
than needed, so zero out the temporary buffer at the end of write_pool().

Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Jason A. Donenfeld
434537ae54 random: remove outdated INT_MAX >> 6 check in urandom_read()
In 79a8468747 ("random: check for increase of entropy_count because of
signed conversion"), a number of checks were added around what values
were passed to account(), because account() was doing fancy fixed point
fractional arithmetic, and a user had some ability to pass large values
directly into it. One of things in that commit was limiting those values
to INT_MAX >> 6. The first >> 3 was for bytes to bits, and the next >> 3
was for bits to 1/8 fractional bits.

However, for several years now, urandom reads no longer touch entropy
accounting, and so this check serves no purpose. The current flow is:

urandom_read_nowarn()-->get_random_bytes_user()-->chacha20_block()

Of course, we don't want that size_t to be truncated when adding it into
the ssize_t. But we arrive at urandom_read_nowarn() in the first place
either via ordinary fops, which limits reads to MAX_RW_COUNT, or via
getrandom() which limits reads to INT_MAX.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:00 +01:00
Jason A. Donenfeld
04ec96b768 random: make more consistent use of integer types
We've been using a flurry of int, unsigned int, size_t, and ssize_t.
Let's unify all of this into size_t where it makes sense, as it does in
most places, and leave ssize_t for return values with possible errors.

In addition, keeping with the convention of other functions in this
file, functions that are dealing with raw bytes now take void *
consistently instead of a mix of that and u8 *, because much of the time
we're actually passing some other structure that is then interpreted as
bytes by the function.

We also take the opportunity to fix the outdated and incorrect comment
in get_random_bytes_arch().

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:13:54 +01:00
Antoniu Miclaus
2be8795a60 MAINTAINERS: add maintainer for ADMV1014 driver
Add myself as maintainer for the ADMV1014 driver.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Link: https://lore.kernel.org/r/20220215081216.67706-4-antoniu.miclaus@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:06 +00:00
Antoniu Miclaus
0ac02bf5bd Documentation: ABI: testing: admv1014: add ABI docs
Add documentation for the use of the Digital Attenuator gain.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Link: https://lore.kernel.org/r/20220215081216.67706-3-antoniu.miclaus@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:06 +00:00
Antoniu Miclaus
b4112083b1 dt-bindings: iio: frequency: add admv1014 binding
Add device tree bindings for the ADMV1014 Upconverter.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220215081216.67706-2-antoniu.miclaus@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:06 +00:00
Antoniu Miclaus
f4eb9ac784 iio: frequency: admv1014: add support for ADMV1014
The ADMV1014 is a silicon germanium (SiGe), wideband,
microwave downconverter optimized for point to point microwave
radio designs operating in the 24 GHz to 44 GHz frequency range.

Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADMV1014.pdf
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Link: https://lore.kernel.org/r/20220215081216.67706-1-antoniu.miclaus@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:06 +00:00
Cosmin Tanislav
cbab791c5e iio: accel: add ADXL367 driver
The ADXL367 is an ultralow power, 3-axis MEMS accelerometer.

The ADXL367 does not alias input signals to achieve ultralow power
consumption, it samples the full bandwidth of the sensor at all
data rates. Measurement ranges of +-2g, +-4g, and +-8g are available,
with a resolution of 0.25mg/LSB on the +-2 g range.

In addition to its ultralow power consumption, the ADXL367
has many features to enable true system level power reduction.
It includes a deep multimode output FIFO, a built-in micropower
temperature sensor, and an internal ADC for synchronous conversion
of an additional analog input.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220214073810.781016-6-cosmin.tanislav@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:06 +00:00
Cosmin Tanislav
27ae7f9d92 dt-bindings: iio: accel: add ADXL367
The ADXL367 is an ultralow power, 3-axis MEMS accelerometer.

The ADXL367 does not alias input signals to achieve ultralow power
consumption, it samples the full bandwidth of the sensor at all
data rates. Measurement ranges of +-2g, +-4g, and +-8g are available,
with a resolution of 0.25mg/LSB on the +-2 g range.

In addition to its ultralow power consumption, the ADXL367
has many features to enable true system level power reduction.
It includes a deep multimode output FIFO, a built-in micropower
temperature sensor, and an internal ADC for synchronous conversion
of an additional analog input.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220214073810.781016-5-cosmin.tanislav@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:06 +00:00
Cosmin Tanislav
06a4a0cf69 iio: ABI: add note about configuring other attributes during buffer capture
It might be impossible to configure other attributes (e.g.: events, scale,
sampling rate) if they impact the currently active buffer capture session.

On ADXL367, writing to register before 0x2E requires the device to be
placed in standby mode, otherwise the changes might be effective for
only part of a measurement.

To ensure this requirement, the configuration attributes of the IIO
device try to claim direct mode before switching to standby mode.
During a buffer capture, direct mode cannot be claimed, and the
attribute write callback returns -EBUSY.

Describe this behavior in the buffer/enable attribute description.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220214073810.781016-4-cosmin.tanislav@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:05 +00:00
Cosmin Tanislav
89d1858486 iio: ABI: document mag_referenced
Some accelerometers that support activity and inactivity
events also support a referenced mode, in which the
gravitational acceleration is taken as a point of
reference before comparing the acceleration to the
specified activity and inactivity magnitude.

For example, in the case of the ADXL367, for activity
detection, the formula is:

abs(acceleration - reference) > magnitude

Add a new event type that makes this behavior clear.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220214073810.781016-3-cosmin.tanislav@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:05 +00:00
Cosmin Tanislav
a1a5cfe70c iio: introduce mag_referenced
Some accelerometers that support activity and inactivity
events also support a referenced mode, in which the
gravitational acceleration is taken as a point of
reference before comparing the acceleration to the
specified activity and inactivity magnitude.

For example, in the case of the ADXL367, for activity
detection, the formula is:

abs(acceleration - reference) > magnitude

Add a new event type that makes this behavior clear.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Link: https://lore.kernel.org/r/20220214073810.781016-2-cosmin.tanislav@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:05 +00:00
Jan Luebbe
b38da7feef dt-bindings: iio: adc: microchip,mcp3201: fix interface type (I2C -> SPI)
This family of ADCs uses SPI, not I2C.

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Link: https://lore.kernel.org/r/20220216162312.4064-1-jlu@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-02-21 19:33:05 +00:00
Jonathan Cameron
cf890fe8ae iio:adc:ad7280a: Move out of staging
This is a rather unusual device (in IIO anyway).  However, it has
a near to standard userspace ABI.

Note the work to move this out of staging was done against a minimal
QEMU model, which doesn't model all the features of the device.
I have no intention to upstream the QEMU model as it was developed
just to enable this driver cleanup.

ad7280a-hacks

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-21-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
48fb57697e staging:iio:adc:ad7280a: Use more conservative delays to allow 105C operation.
The datasheet provides timings for operating this device at up to 105
degrees centigrade. Adopt these more conservative timings.

Suggested-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-20-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
6c6bc851d8 staging:iio:adc:ad7280a: Remove shift from cb_mask state cache.
Making the local storage of the Cell Balance mask a simple
bitmap and then shifting it only at time of register write simplifies
several code paths.

Suggested-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-19-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
bc6fbf1177 iio:adc:ad7280a: Document ABI for cell balance switches
Very minimal ABI docs. This is unusual enough that I'd expect anyone
who actually wanted to touch them to go look at the datasheet.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-18-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
aa1b784def dt-bindings:iio:adc:ad7280a: Add binding
Add a binding for this Lithium Ion Battery monitoring chip/chain of chips
as it is now clean and ready to move out of staging.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-17-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
d2960145b3 staging:iio:adc:ad7280a: Drop buggy support for early termination of AUX alert.
This functionality is intended to allow for a few temperature
sensors to be missing (and hence not worth reading) on the final
device in a chain.  The ones removed are 3 and 5 (unlike for
the ADC channels where it is 4 and 5).

The datasheet includes a foot note 3 to Table 12 that makes this complex
to support.

"(3) To remove AUX5 or AUX5 and AUX3 from the alert detection, conversions
on three auxiliary ADC input channels only must be selected in the
control register."

This mode has never been supported by the driver.

As this support would be complex to add and the rework is being done
against a QEMU model developed for the purposes of verifying nothing
is broken, it is better to drop this support for now.

Reported-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-16-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
219def4475 staging:iio:adc:ad7280a: Use device properties to replace platform data.
Convert all the device specific info that was previously in platform data
over to generic firmware query interfaces.

dt-bindings to follow shortly.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-15-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
dfa258c066 staging:iio:adc:ad7280a: Use a local dev pointer to avoid &spi->dev
We use this a few times already and it is about to get worse, so
introduce a local variable to simplify things.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-14-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
9010ac1c71 staging:iio:ad7280a: Reflect optionality of irq in ABI
Given the irq is optional, let us remove the interfaces related to
events when it is not present.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-13-jic23@kernel.org
2022-02-21 19:33:05 +00:00
Jonathan Cameron
65ba4ab6f0 staging:iio:adc:ad7280a: Cleanup includes
Drop used includes, add a few missing ones and reorder.
The include-what-you-use tool output was considered in making this
change.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20220206190328.333093-12-jic23@kernel.org
2022-02-21 19:33:05 +00:00