Some systems use a special keyboard shortcut to mute speaker audio. On systems using CS35L41 HDA which have this shortcut, add a mechanism which uses ACPI notifications to determine when the shortcut is pressed, and then mute the amps inside the driver.
Since this is not a normal mute mechanism, it does not go through userspace. To allow userspace to be able to track this special state, add an ALSA control which tracks the state of this forced mute
Changes since v2: - Fixed compile issue when CONFIG_ACPI is missing
Changes since v3: - Split first patch into 3 separate patches - Ensure all acpi code is protected by check for CONFIG_ACPI in realtek driver
Stefan Binding (4): ALSA: hda: cs35l41: Add notification support into component binding ALSA: hda/realtek: Support ACPI Notification framework via component binding ALSA: hda: cs35l41: Support mute notifications for CS35L41 HDA ALSA: hda: cs35l41: Add read-only ALSA control for forced mute
sound/pci/hda/cs35l41_hda.c | 132 ++++++++++++++++++++++++++++++---- sound/pci/hda/cs35l41_hda.h | 3 + sound/pci/hda/hda_component.h | 4 ++ sound/pci/hda/patch_realtek.c | 83 ++++++++++++++++++++- 4 files changed, 208 insertions(+), 14 deletions(-)