[v6,0/2] Read _SUB from ACPI to be able to identify firmware

Message

Stefan Binding July 7, 2022, 3:10 p.m. UTC

CS35L41 has a DSP which is able to run firmware, as well as a tuning file.
Different systems may want to use different firmwares and tuning files, and
some firmwares/tunings may not be compatible with other systems.
To allow a system to select the correct fimware/tuning, we can read an _SUB
from the ACPI. This _SUB can then be used to uniquely identify the system
in the firmware/tuning file name.

Add a helper function which reads the _SUB, so this can be used by other
parts in the future.
Add support inside the CS35L41 ASoC driver to read this _SUB, and save it
appropriately.

Changes since v5:
- Clean up return codes
- Refactor length calculation
- Allow fallback to existing behaviour when bad ACPI is detected

Changes since v4:
- Rename function

Changes since v3:
- Fix 32 bit format string warning

Changes since v2:
- Fix error in function prototype

Changes since v1:
- Add length validation for SSID String
- Rename API
- Allocate memory inside API
- Use ACPI_HANDLE macro instead of ACPI_COMPANION
- Improve error handling

Stefan Binding (2):
  ACPI: utils: Add api to read _SUB from ACPI
  ASoC: cs35l41: Read System Name from ACPI _SUB to identify firmware

 drivers/acpi/utils.c       | 38 ++++++++++++++++++++++++++++++++++++++
 include/linux/acpi.h       |  6 ++++++
 sound/soc/codecs/cs35l41.c | 30 ++++++++++++++++++++++++++++++
 3 files changed, 74 insertions(+)

Comments

Mark Brown July 15, 2022, 5:22 p.m. UTC | #1

On Thu, 7 Jul 2022 16:10:35 +0100, Stefan Binding wrote:
> CS35L41 has a DSP which is able to run firmware, as well as a tuning file.
> Different systems may want to use different firmwares and tuning files, and
> some firmwares/tunings may not be compatible with other systems.
> To allow a system to select the correct fimware/tuning, we can read an _SUB
> from the ACPI. This _SUB can then be used to uniquely identify the system
> in the firmware/tuning file name.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/2] ACPI: utils: Add api to read _SUB from ACPI
      commit: 93064e15c8a3a8394319a11b8037666e4b7d653d
[2/2] ASoC: cs35l41: Read System Name from ACPI _SUB to identify firmware
      commit: c1ad138822a1be95a7a7b122521c2415583a0c26

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark