ALSA/hda: intel-sdw-acpi: add support for sdw-manager-list property read

The DisCo for SoundWire 2.0 spec adds support for a new
sdw-manager-list property.  Add it in backwards-compatible mode with
'sdw-master-count', which assumed that all links between 0..count-1
exist.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20241001070611.63288-5-yung-chuan.liao@linux.intel.com

include/linux/soundwire/sdw_intel.h

@@ -227,7 +227,7 @@ struct sdw_intel_ops {
 /**
  * struct sdw_intel_acpi_info - Soundwire Intel information found in ACPI tables
  * @handle: ACPI controller handle
- * @count: link count found with "sdw-master-count" property
+ * @count: link count found with "sdw-master-count" or "sdw-manager-list" property
  * @link_mask: bit-wise mask listing links enabled by BIOS menu
  *
  * this structure could be expanded to e.g. provide all the _ADR

sound/hda/intel-sdw-acpi.c

@@ -57,8 +57,10 @@ sdw_intel_scan_controller(struct sdw_intel_acpi_info *info)
 {
 	struct acpi_device *adev = acpi_fetch_acpi_dev(info->handle);
 	struct fwnode_handle *fwnode;
+	unsigned long list;
 	unsigned int i;
 	u32 count;
+	u32 tmp;
 	int ret;
 
 	if (!adev)
@@ -66,10 +68,9 @@ sdw_intel_scan_controller(struct sdw_intel_acpi_info *info)
 
 	fwnode = acpi_fwnode_handle(adev);
 
-	/* Found controller, find links supported */
-	ret = fwnode_property_read_u32(fwnode, "mipi-sdw-master-count", &count);
-
 	/*
+	 * Found controller, find links supported
+	 *
 	 * In theory we could check the number of links supported in
 	 * hardware, but in that step we cannot assume SoundWire IP is
 	 * powered.
@@ -80,12 +81,20 @@ sdw_intel_scan_controller(struct sdw_intel_acpi_info *info)
 	 *
 	 * We will check the hardware capabilities in the startup() step
 	 */
-
+	ret = fwnode_property_read_u32(fwnode, "mipi-sdw-manager-list", &tmp);
+	if (ret) {
+		ret = fwnode_property_read_u32(fwnode, "mipi-sdw-master-count", &count);
 		if (ret) {
 			dev_err(&adev->dev,
-			"Failed to read mipi-sdw-master-count: %d\n", ret);
+				"Failed to read mipi-sdw-master-count: %d\n",
+				ret);
 			return ret;
 		}
+		list = GENMASK(count - 1, 0);
+	} else {
+		list = tmp;
+		count = hweight32(list);
+	}
 
 	/* Check count is within bounds */
 	if (count > SDW_INTEL_MAX_LINKS) {
@@ -103,7 +112,7 @@ sdw_intel_scan_controller(struct sdw_intel_acpi_info *info)
 	info->count = count;
 	info->link_mask = 0;
 
-	for (i = 0; i < count; i++) {
+	for_each_set_bit(i, &list, SDW_INTEL_MAX_LINKS) {
 		if (ctrl_link_mask && !(ctrl_link_mask & BIT(i))) {
 			dev_dbg(&adev->dev,
 				"Link %d masked, will not be enabled\n", i);