ACPM commands that return more than 8 bytes currently don't work
correctly, as this driver ignores any such returned bytes.
This is evident in at least acpm_pmic_bulk_read(), where up to 8
registers can be read back and those 8 register values are placed
starting at &xfer->rxd[8].
The reason is that xfter->rxlen is initialized with the size of a
pointer (8 bytes), rather than the size of the byte array that pointer
points to (16 bytes)
Update the code such that we set the number of bytes expected to be the
size of the rx buffer.
Note1: While different commands have different lengths rx buffers, we
have to specify the same length for all rx buffers since acpm_get_rx()
assumes they're all the same length.
Note2: The different commands also have different lengths tx buffers,
but before switching the code to use the minimum possible length, some
more testing would have to be done to ensure this works correctly in
all situations. It seems wiser to just apply this fix here without
additional logic changes for now.
Fixes: a88927b534 ("firmware: add Exynos ACPM protocol driver")
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250319-acpm-fixes-v2-1-ac2c1bcf322b@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Alive Clock and Power Manager (ACPM) Message Protocol is defined for
the purpose of communication between the ACPM firmware and masters
(AP, AOC, ...). ACPM firmware operates on the Active Power Management
(APM) module that handles overall power activities.
ACPM and masters regard each other as independent hardware component and
communicate with each other using mailbox messages and shared memory.
This protocol driver provides the interface for all the client drivers
making use of the features offered by the APM. Add ACPM protocol support.
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20250213-gs101-acpm-v9-2-8b0281b93c8b@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
