1 files changed, 62 insertions, 0 deletions
diff --git a/sound/soc/amd/acp/amd-sdw-acpi.c b/sound/soc/amd/acp/amd-sdw-acpi.c
new file mode 100644
index 000000000000..babd841d3296
--- /dev/null
+++ b/sound/soc/amd/acp/amd-sdw-acpi.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license. When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2023 Advanced Micro Devices, Inc. All rights reserved.
+//
+// Authors: Vijendar Mukunda <[email protected]>
+
+/*
+ * SDW AMD ACPI scan helper function
+ */
+
+#include <linux/acpi.h>
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/fwnode.h>
+#include <linux/module.h>
+#include <linux/soundwire/sdw_amd.h>
+#include <linux/string.h>
+
+int amd_sdw_scan_controller(struct sdw_amd_acpi_info *info)
+{
+	struct acpi_device *adev = acpi_fetch_acpi_dev(info->handle);
+	u32 sdw_bitmap = 0;
+	u8 count = 0;
+	int ret;
+
+	if (!adev)
+		return -EINVAL;
+
+	/* Found controller, find links supported */
+	ret = fwnode_property_read_u32_array(acpi_fwnode_handle(adev),
+					     "mipi-sdw-manager-list", &sdw_bitmap, 1);
+	if (ret) {
+		dev_err(&adev->dev,
+			"Failed to read mipi-sdw-manager-list: %d\n", ret);
+		return -EINVAL;
+	}
+	count = hweight32(sdw_bitmap);
+	/* Check count is within bounds */
+	if (count > info->count) {
+		dev_err(&adev->dev, "Manager count %d exceeds max %d\n",
+			count, info->count);
+		return -EINVAL;
+	}
+
+	if (!count) {
+		dev_dbg(&adev->dev, "No SoundWire Managers detected\n");
+		return -EINVAL;
+	}
+	dev_dbg(&adev->dev, "ACPI reports %d SoundWire Manager devices\n", count);
+	info->link_mask = sdw_bitmap;
+	return 0;
+}
+EXPORT_SYMBOL_NS(amd_sdw_scan_controller, SND_AMD_SOUNDWIRE_ACPI);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("AMD SoundWire ACPI helpers");