regmap: regmap_multi_reg_read(): make register list const

Mark the list of registers passed into regmap_multi_reg_read() as a
pointer to const. This allows the caller to define the register list
as

regmap: regmap_multi_reg_read(): make register list const

Mark the list of registers passed into regmap_multi_reg_read() as a
pointer to const. This allows the caller to define the register list
as const data.

This requires making the same change to _regmap_bulk_read(), which is
called by regmap_multi_reg_read().

Signed-off-by: Richard Fitzgerald <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: place foo / 8 and foo % 8 closer to each other

On x86 the compiler (gcc (Debian 14.2.0-8) 14.2.0) may generate
a better code if it sees division and modulo goes together.

Function

regmap: place foo / 8 and foo % 8 closer to each other

On x86 the compiler (gcc (Debian 14.2.0-8) 14.2.0) may generate
a better code if it sees division and modulo goes together.

Function old new delta
__regmap_init 3740 3732 -8
Total: Before=31159, After=31151, chg -0.03%

clang (Debian clang version 18.1.8) on x86_64 still shows better code

Function old new delta
__regmap_init 3582 3579 -3
Total: Before=39854, After=39851, chg -0.01%

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Use BITS_TO_BYTES()

BITS_TO_BYTES() is the existing macro which takes care about full
bytes that may fully hold the given amount of bits. Use it.

Signed-off-by: Andy Shevchenko <andriy.shev

regmap: Use BITS_TO_BYTES()

BITS_TO_BYTES() is the existing macro which takes care about full
bytes that may fully hold the given amount of bits. Use it.

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: detach regmap from dev on regmap_exit

At the end of __regmap_init(), if dev is not NULL, regmap_attach_dev()
is called, which adds a devres reference to the regmap, to be able to
retrieve a

regmap: detach regmap from dev on regmap_exit

At the end of __regmap_init(), if dev is not NULL, regmap_attach_dev()
is called, which adds a devres reference to the regmap, to be able to
retrieve a dev's regmap by name using dev_get_regmap().

When calling regmap_exit, the opposite does not happen, and the
reference is kept until the dev is detached.

Add a regmap_detach_dev() function and call it in regmap_exit() to make
sure that the devres reference is not kept.

Cc: [email protected]
Fixes: 72b39f6f2b5a ("regmap: Implement dev_get_regmap()")
Signed-off-by: Cosmin Tanislav <[email protected]>
Rule: add
Link: https://lore.kernel.org/stable/20241128130554.362486-1-demonsingur%40gmail.com
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Use correct format specifier for logging range errors

The register addresses are unsigned ints so we should use %u not %d to
log them.

Signed-off-by: Mark Brown <[email protected]>
Link: h

regmap: Use correct format specifier for logging range errors

The register addresses are unsigned ints so we should use %u not %d to
log them.

Signed-off-by: Mark Brown <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: maple: Provide lockdep (sub)class for maple tree's internal lock

In some cases when using the maple tree register cache, the lockdep
validator might complain about invalid deadlocks:

[7.131

regmap: maple: Provide lockdep (sub)class for maple tree's internal lock

In some cases when using the maple tree register cache, the lockdep
validator might complain about invalid deadlocks:

[7.131886] Possible interrupt unsafe locking scenario:

[7.131890] CPU0 CPU1
[7.131893] ---- ----
[7.131896] lock(&mt->ma_lock);
[7.131904] local_irq_disable();
[7.131907] lock(rockchip_drm_vop2:3114:(&vop2_regmap_config)->lock);
[7.131916] lock(&mt->ma_lock);
[7.131925] <Interrupt>
[7.131928] lock(rockchip_drm_vop2:3114:(&vop2_regmap_config)->lock);
[7.131936]
*** DEADLOCK ***

[7.131939] no locks held by swapper/0/0.
[7.131944]
the shortest dependencies between 2nd lock and 1st lock:
[7.131950] -> (&mt->ma_lock){+.+.}-{2:2} {
[7.131966] HARDIRQ-ON-W at:
[7.131973] lock_acquire+0x200/0x330
[7.131986] _raw_spin_lock+0x50/0x70
[7.131998] regcache_maple_write+0x68/0xe0
[7.132010] regcache_write+0x6c/0x90
[7.132019] _regmap_read+0x19c/0x1d0
[7.132029] _regmap_update_bits+0xc0/0x148
[7.132038] regmap_update_bits_base+0x6c/0xa8
[7.132048] rk8xx_probe+0x22c/0x3d8
[7.132057] rk8xx_spi_probe+0x74/0x88
[7.132065] spi_probe+0xa8/0xe0

[...]

[7.132675] }
[7.132678] ... key at: [<ffff800082943c20>] __key.0+0x0/0x10
[7.132691] ... acquired at:
[7.132695] _raw_spin_lock+0x50/0x70
[7.132704] regcache_maple_write+0x68/0xe0
[7.132714] regcache_write+0x6c/0x90
[7.132724] _regmap_read+0x19c/0x1d0
[7.132732] _regmap_update_bits+0xc0/0x148
[7.132741] regmap_field_update_bits_base+0x74/0xb8
[7.132751] vop2_plane_atomic_update+0x480/0x14d8 [rockchipdrm]
[7.132820] drm_atomic_helper_commit_planes+0x1a0/0x320 [drm_kms_helper]

[...]

[7.135112] -> (rockchip_drm_vop2:3114:(&vop2_regmap_config)->lock){-...}-{2:2} {
[7.135130] IN-HARDIRQ-W at:
[7.135136] lock_acquire+0x200/0x330
[7.135147] _raw_spin_lock_irqsave+0x6c/0x98
[7.135157] regmap_lock_spinlock+0x20/0x40
[7.135166] regmap_read+0x44/0x90
[7.135175] vop2_isr+0x90/0x290 [rockchipdrm]
[7.135225] __handle_irq_event_percpu+0x124/0x2d0

In the example above, the validator seems to get the scope of
dependencies wrong, since the regmap instance used in rk8xx-spi driver
has nothing to do with the instance from vop2.

Improve validation by sharing the regmap's lockdep class with the maple
tree's internal lock, while also providing a subclass for the latter.

Signed-off-by: Cristian Ciocaltea <[email protected]>
Link: https://patch.msgid.link/20241031-regmap-maple-lockdep-fix-v2-1-06a3710f3623@collabora.com
Signed-off-by: Mark Brown <[email protected]>

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move asm/unaligned.h to linux/unaligned.h

asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-

move asm/unaligned.h to linux/unaligned.h

asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

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regmap: Hold the regmap lock when allocating and freeing the cache

For the benefit of the maple tree's lockdep checking hold the lock while
creating and exiting the cache.

Signed-off-by: Mark Brown

regmap: Hold the regmap lock when allocating and freeing the cache

For the benefit of the maple tree's lockdep checking hold the lock while
creating and exiting the cache.

Signed-off-by: Mark Brown <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Implement regmap_multi_reg_read()

regmap_multi_reg_read() is similar to regmap_bilk_read() but reads from
an array of non-sequential registers.

Signed-off-by: Guenter Roeck <linux@roeck-us.

regmap: Implement regmap_multi_reg_read()

regmap_multi_reg_read() is similar to regmap_bilk_read() but reads from
an array of non-sequential registers.

Signed-off-by: Guenter Roeck <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Switch to use kmemdup_array()

Let the kememdup_array() take care about multiplication and possible
overflows.

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https:

regmap: Switch to use kmemdup_array()

Let the kememdup_array() take care about multiplication and possible
overflows.

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Add regmap_read_bypassed()

Add a regmap_read_bypassed() to allow reads from the hardware registers
while the regmap is in cache-only mode.

A typical use for this is to keep the cache in cac

regmap: Add regmap_read_bypassed()

Add a regmap_read_bypassed() to allow reads from the hardware registers
while the regmap is in cache-only mode.

A typical use for this is to keep the cache in cache-only mode until
the hardware has reached a valid state, but one or more status registers
must be polled to determine when this state is reached.

For example, firmware download on the cs35l56 can take several seconds if
there are multiple amps sharing limited bus bandwidth. This is too long
to block in probe() so it is done as a background task. The device must
be soft-reset to reboot the firmware and during this time the registers are
not accessible, so the cache should be in cache-only. But the driver must
poll a register to detect when reboot has completed.

Signed-off-by: Richard Fitzgerald <[email protected]>
Fixes: 8a731fd37f8b ("ASoC: cs35l56: Move utility functions to shared file")
Link: https://msgid.link/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: rework ->max_register handling

When regmap consists of single register, 'regmap' subsystem is unable to
understand whether ->max_register is set or not, because in both cases it
is equal to

regmap: rework ->max_register handling

When regmap consists of single register, 'regmap' subsystem is unable to
understand whether ->max_register is set or not, because in both cases it
is equal to zero. It leads to that the logic based on value of
->max_register doesn't work. For example using of REGCACHE_FLAT fails.

This patch introduces an extra parameter to regmap config, indicating
that zero value in ->max_register is authentic.

Signed-off-by: Jan Dakinevich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: fix regmap_noinc_write() description

Change "Write data from" -> "Write data to".

Signed-off-by: Hugo Villeneuve <[email protected]>
Link: https://lore.kernel.org/r/20231121230900.37

regmap: fix regmap_noinc_write() description

Change "Write data from" -> "Write data to".

Signed-off-by: Hugo Villeneuve <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: prevent noinc writes from clobbering cache

Currently, noinc writes are cached as if they were standard incrementing
writes, overwriting unrelated register values in the cache. Instead, we
wa

regmap: prevent noinc writes from clobbering cache

Currently, noinc writes are cached as if they were standard incrementing
writes, overwriting unrelated register values in the cache. Instead, we
want to cache the last value written to the register, as is done in the
accelerated noinc handler (regmap_noinc_readwrite).

Fixes: cdf6b11daa77 ("regmap: Add regmap_noinc_write API")
Signed-off-by: Ben Wolsieffer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: fix NULL deref on lookup

Not all regmaps have a name so make sure to check for that to avoid
dereferencing a NULL pointer when dev_get_regmap() is used to lookup a
named regmap.

Fixes: e848

regmap: fix NULL deref on lookup

Not all regmaps have a name so make sure to check for that to avoid
dereferencing a NULL pointer when dev_get_regmap() is used to lookup a
named regmap.

Fixes: e84861fec32d ("regmap: dev_get_regmap_match(): fix string comparison")
Cc: [email protected] # 5.8
Cc: Marc Kleine-Budde <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Remove dynamic allocation warnings for rbtree and maple

Thanks to Dan and Guenter's very prompt updates of the rbtree and maple
caches to support GPF_ATOMIC allocations and since the update

regmap: Remove dynamic allocation warnings for rbtree and maple

Thanks to Dan and Guenter's very prompt updates of the rbtree and maple
caches to support GPF_ATOMIC allocations and since the update shook out
a bunch of users at least some of whom have been suitably careful about
ensuring that the cache is prepoulated so there are no dynamic
allocations after init let's revert the warnings.

Signed-off-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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regmap: Reject fast_io regmap configurations with RBTREE and MAPLE caches

REGCACHE_RBTREE and REGCACHE_MAPLE dynamically allocate memory for regmap
operations. This is incompatible with spinlock bas

regmap: Reject fast_io regmap configurations with RBTREE and MAPLE caches

REGCACHE_RBTREE and REGCACHE_MAPLE dynamically allocate memory for regmap
operations. This is incompatible with spinlock based locking which is used
for fast_io operations. Reject affected configurations.

Signed-off-by: Guenter Roeck <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Drop initial version of maximum transfer length fixes

When problems were noticed with the register address not being taken
into account when limiting raw transfers with I2C devices we fixed

regmap: Drop initial version of maximum transfer length fixes

When problems were noticed with the register address not being taken
into account when limiting raw transfers with I2C devices we fixed this
in the core. Unfortunately it has subsequently been realised that a lot
of buses were relying on the prior behaviour, partly due to unclear
documentation not making it obvious what was intended in the core. This
is all more involved to fix than is sensible for a fix commit so let's
just drop the original fixes, a separate commit will fix the originally
observed problem in an I2C specific way

Fixes: 3981514180c9 ("regmap: Account for register length when chunking")
Fixes: c8e796895e23 ("regmap: spi-avmm: Fix regmap_bus max_raw_write")
Signed-off-by: Mark Brown <[email protected]>
Reviewed-by: Xu Yilun <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Revert "add 64-bit mode support" and Co.

With unsigned int type we never ever can pass 64-bit value.
Remove never properly worked code.

Note, there are no users in kernel for this size of r

regmap: Revert "add 64-bit mode support" and Co.

With unsigned int type we never ever can pass 64-bit value.
Remove never properly worked code.

Note, there are no users in kernel for this size of register
offsets or data.

This reverts commit afcc00b91f1865f6d0bbdb687dd642ce8a3c3c9e.

Also revert other 64-bit code excerpts in the regmap implementation
that had been induced by the false impression made by the above
mentioned change that there is a support of that data size.

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Drop early readability check

We have some drivers that have a use case for cached write only
registers, doing read/modify/writes on read only registers in order to
work more easily with bitf

regmap: Drop early readability check

We have some drivers that have a use case for cached write only
registers, doing read/modify/writes on read only registers in order to
work more easily with bitfields. Go back to trying the cache before we
check if we can read from the device.

Fixes: eab5abdeb79f0 ("regmap: Check for register readability before checking cache during read")
Reported-by: Konrad Dybcio <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/20230615-regmap-drop-early-readability-v1-1-8135094362de@kernel.org
Signed-off-by: Mark Brown <[email protected]>

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regmap: Check for register readability before checking cache during read

Ensure that we don't return a spurious cache hit for unreadable registers
(eg, with the flat cache which doesn't understand s

regmap: Check for register readability before checking cache during read

Ensure that we don't return a spurious cache hit for unreadable registers
(eg, with the flat cache which doesn't understand sparseness) by checking
for readability before we do a cache lookup.

Signed-off-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/20230613-b4-regmap-check-readability-before-cache-v1-1-b144c0b01ed9@kernel.org
Signed-off-by: Mark Brown <[email protected]>

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regmap: Add debugfs file for forcing field writes

`_regmap_update_bits()` checks if the current register value differs
from the new value, and only writes to the register if they differ. When
testin

regmap: Add debugfs file for forcing field writes

`_regmap_update_bits()` checks if the current register value differs
from the new value, and only writes to the register if they differ. When
testing hardware drivers, it might be desirable to always force a
register write, for example when writing to a `regmap_field`. This
enables and simplifies testing and verification of the hardware
interaction. For example, when using a hardware mock/simulation model,
one can then more easily verify that the driver makes the correct
expected register writes during certain events.

Add a bool variable `force_write_field` and a corresponding debugfs
entry to enable this. Since this feature could interfere with driver
operation, guard it with a macro.

Signed-off-by: Waqar Hameed <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Add missing cache_only checks

The current behaviour around cache_only is slightly inconsistent,
most paths will only check cache_only if cache_bypass is false,
and will return -EBUSY if a re

regmap: Add missing cache_only checks

The current behaviour around cache_only is slightly inconsistent,
most paths will only check cache_only if cache_bypass is false,
and will return -EBUSY if a read attempts to go to the hardware
whilst cache_only is true. However, a couple of paths will not check
cache_only at all. The most notable of these being regmap_raw_read
which will check cache_only in the case it processes the transaction
one register at a time, but not in the case it handles them as a
block. In the typical case a device has been put into cache_only
whilst powered down this can cause physical reads to happen whilst the
device is unavailable.

Add a check in regmap_raw_read and move the check in regmap_noinc_read,
adding a check for cache_bypass, such that all paths are covered and
consistent.

Signed-off-by: Charles Keepax <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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regmap: Account for register length when chunking

Currently, when regmap_raw_write() splits the data, it uses the
max_raw_write value defined for the bus. For any bus that includes
the target regis

regmap: Account for register length when chunking

Currently, when regmap_raw_write() splits the data, it uses the
max_raw_write value defined for the bus. For any bus that includes
the target register address in the max_raw_write value, the chunked
transmission will always exceed the maximum transmission length.
To avoid this problem, subtract the length of the register and the
padding from the maximum transmission.

Signed-off-by: Jim Wylder <[email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]

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regmap: allow upshifting register addresses before performing operations

Similar to the existing reg_downshift mechanism, that is used to
translate register addresses on busses that have a smaller a

regmap: allow upshifting register addresses before performing operations

Similar to the existing reg_downshift mechanism, that is used to
translate register addresses on busses that have a smaller address
stride, it's also possible to want to upshift register addresses.

Such a case was encountered when network PHYs and PCS that usually sit
on a MDIO bus (16-bits register with a stride of 1) are integrated
directly as memory-mapped devices. Here, the same register layout
defined in 802.3 is used, but the register now have a larger stride.

Introduce a mechanism to also allow upshifting register addresses.
Re-purpose reg_downshift into a more generic, signed reg_shift, whose
sign indicates the direction of the shift. To avoid confusion, also
introduce macros to explicitly indicate if we want to downshift or
upshift.

For bisectability, change any use of reg_downshift to use reg_shift.

Signed-off-by: Maxime Chevallier <[email protected]>
Tested-by: Colin Foster <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

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