[PATCH 4/4] ALSA/hda: intel-sdw-acpi: add support for sdw-manager-list property read

[Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>]

From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
 include/linux/soundwire/sdw_intel.h |  2 +-
 sound/hda/intel-sdw-acpi.c          | 25 +++++++++++++++++--------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/include/linux/soundwire/sdw_intel.h b/include/linux/soundwire/sdw_intel.h
index 37ae69365fe2..734dc1fa3b5b 100644
--- a/include/linux/soundwire/sdw_intel.h
+++ b/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
diff --git a/sound/hda/intel-sdw-acpi.c b/sound/hda/intel-sdw-acpi.c
index 582e761e7b9f..ed530e0dd4dd 100644
--- a/sound/hda/intel-sdw-acpi.c
+++ b/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.
@@ -80,11 +81,19 @@ 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) {
-		dev_err(&adev->dev,
-			"Failed to read mipi-sdw-master-count: %d\n", ret);
-		return 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);
+			return ret;
+		}
+		list = GENMASK(count - 1, 0);
+	} else {
+		list = tmp;
+		count = hweight32(list);
 	}
 
 	/* Check count is within bounds */
@@ -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);
-- 
2.43.0