linux.git/drivers/base/regmap/regmap.c, branch v6.5-rc2

regmap: Drop early readability check

2023-06-16T11:56:13+00:00

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 
Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20230615-regmap-drop-early-readability-v1-1-8135094362de@kernel.org
Signed-off-by: Mark Brown

regmap: Check for register readability before checking cache during read

2023-06-14T11:27:16+00:00

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

regmap: Add debugfs file for forcing field writes

2023-06-13T12:15:04+00:00

`_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 
Link: https://lore.kernel.org/r/pnd1qifa7sj.fsf@axis.com
Signed-off-by: Mark Brown

regmap: Merge up v6.4-rc6

2023-06-12T13:50:15+00:00

The fix for maple tree RCU locking on sync is a dependency for the
block sync code for the maple tree.

regmap: Add missing cache_only checks

2023-06-01T11:32:53+00:00

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 
Link: https://lore.kernel.org/r/20230601101036.1499612-2-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown

regmap: Account for register length when chunking

2023-05-18T01:53:42+00:00

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

regmap: allow upshifting register addresses before performing operations

2023-04-07T16:28:19+00:00

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 
Tested-by: Colin Foster 
Link: https://lore.kernel.org/r/20230407152604.105467-1-maxime.chevallier@bootlin.com
Signed-off-by: Mark Brown

regmap: Support paging for buses with reg_read()/reg_write()

2023-03-27T00:42:37+00:00

We don't currently support paging for regmaps where the I/O happens through
bus provided reg_read() and reg_write() operatons, we simply ignore the
range since nothing is wired up properly. Wire things up.

Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20230324-regmap-reg-read-write-page-v1-1-1fbc0dac67ae@kernel.org

regmap: add a helper to translate the register address

2023-03-24T19:02:16+00:00

Register addresses passed to regmap operations can be offset with
regmap.reg_base and downshifted with regmap.reg_downshift.

Add a helper to apply both these operations and return the translated
address, that we can then use to perform the actual register operation
ont the underlying bus.

Signed-off-by: Maxime Chevallier 
Link: https://lore.kernel.org/r/20230324093644.464704-2-maxime.chevallier@bootlin.com
Signed-off-by: Mark Brown

regmap: apply reg_base and reg_downshift for single register ops

2023-01-31T12:14:48+00:00

reg_base and reg_downshift currently don't have any effect if used with
a regmap_bus or regmap_config which only offers single register
operations (ie. reg_read, reg_write and optionally reg_update_bits).

Fix that and take them into account also for regmap_bus with only
reg_read and read_write operations by applying reg_base and
reg_downshift in _regmap_bus_reg_write, _regmap_bus_reg_read.

Also apply reg_base and reg_downshift in _regmap_update_bits, but only
in case the operation is carried out with a reg_update_bits call
defined in either regmap_bus or regmap_config.

Fixes: 0074f3f2b1e43d ("regmap: allow a defined reg_base to be added to every address")
Fixes: 86fc59ef818beb ("regmap: add configurable downshift for addresses")
Signed-off-by: Daniel Golle 
Tested-by: Colin Foster 
Link: https://lore.kernel.org/r/Y9clyVS3tQEHlUhA@makrotopia.org
Signed-off-by: Mark Brown