ASoC: soc-acpi: add link_mask field

When interfaces can be pin-muxed, static information from ACPI might
not be enough. Add information on which links needs to be enabled by
hardware/firmware for a specific machine driver to be selected.

When walking through the list of possible machines, links will be
checked, which implies that configurations where multiple links are
required need to be checked first.

Additional criteria will be needed later, such as which SoundWire
Slave devices are actually enabled, but for now this helps detect
between basic configurations.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20190916214251.13130-2-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc-acpi.h

@@ -75,6 +75,7 @@ struct snd_soc_acpi_mach_params {
  * all firmware/topology related fields.
  *
  * @id: ACPI ID (usually the codec's) used to find a matching machine driver.
+ * @link_mask: describes required board layout, e.g. for SoundWire.
  * @drv_name: machine driver name
  * @fw_filename: firmware file name. Used when SOF is not enabled.
  * @board: board name
@@ -90,6 +91,7 @@ struct snd_soc_acpi_mach_params {
 /* Descriptor for SST ASoC machine driver */
 struct snd_soc_acpi_mach {
 	const u8 id[ACPI_ID_LEN];
+	const u32 link_mask;
 	const char *drv_name;
 	const char *fw_filename;
 	const char *board;