firmware: cs_dsp: Remove async regmap writes

[ Upstream commit fe08b7d5085a9774abc30c26d5aebc5b9cdd6091 ]

Change calls to async regmap write functions to use the normal
blocking writes so that the

firmware: cs_dsp: Remove async regmap writes

[ Upstream commit fe08b7d5085a9774abc30c26d5aebc5b9cdd6091 ]

Change calls to async regmap write functions to use the normal
blocking writes so that the cs35l56 driver can use spi_bus_lock() to
gain exclusive access to the SPI bus.

As this is part of a fix, it makes only the minimal change to swap the
functions to the blocking equivalents. There's no need to risk
reworking the buffer allocation logic that is now partially redundant.

The async writes are a 12-year-old workaround for inefficiency of
synchronous writes in the SPI subsystem. The SPI subsystem has since
been changed to avoid the overheads, so this workaround should not be
necessary.

The cs35l56 driver needs to use spi_bus_lock() prevent bus activity
while it is soft-resetting the cs35l56. But spi_bus_lock() is
incompatible with spi_async() calls, which will fail with -EBUSY.

Fixes: 8a731fd37f8b ("ASoC: cs35l56: Move utility functions to shared file")
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20250225131843.113752-2-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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firmware: cs_dsp: Don't allow writes to read-only controls

[ Upstream commit 62412a9357b16a4e39dc582deb2e2a682b92524c ]

Add a check to cs_dsp_coeff_write_ctrl() to abort if the control
is not write

firmware: cs_dsp: Don't allow writes to read-only controls

[ Upstream commit 62412a9357b16a4e39dc582deb2e2a682b92524c ]

Add a check to cs_dsp_coeff_write_ctrl() to abort if the control
is not writeable.

The cs_dsp code originated as an ASoC driver (wm_adsp) where all
controls were exported as ALSA controls. It relied on ALSA to
enforce the read-only permission. Now that the code has been
separated from ALSA/ASoC it must perform its own permission check.

This isn't currently causing any problems so there shouldn't be any
need to backport this. If the client of cs_dsp exposes the control as
an ALSA control, it should set permissions on that ALSA control to
protect it. The few uses of cs_dsp_coeff_write_ctrl() inside drivers
are for writable controls.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20240702110809.16836-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...