3 files changed, 37 insertions, 0 deletions
diff --git a/src/ec/google/chromeec/ec.c b/src/ec/google/chromeec/ec.c
index 8fdfbfbb28..a32b2a54a4 100644
--- a/src/ec/google/chromeec/ec.c
+++ b/src/ec/google/chromeec/ec.c
@@ -723,6 +723,31 @@ int google_chromeec_cbi_get_ssfc(uint32_t *ssfc)
 	return cbi_get_uint32(ssfc, CBI_TAG_SSFC);
 }
 
+bool google_chromeec_get_ucsi_enabled(void)
+{
+	int rv;
+	union ec_common_control cc;
+
+	rv = google_chromeec_check_feature(EC_FEATURE_UCSI_PPM);
+	if (rv < 0) {
+		printk(BIOS_INFO, "Cannot check if EC_FEATURE_UCSI_PPM is available: status = %d\n", rv);
+		return false;
+	}
+
+	if (rv == 0)
+		return false;
+
+	/* Check if PPM is enabled at runtime. */
+	cc.ucsi_enabled = 0;
+	rv = cbi_get_uint32(&cc.raw_value, CBI_TAG_COMMON_CONTROL);
+	if (rv < 0) {
+		printk(BIOS_DEBUG, "Cannot get tag CBI_TAG_COMMON_CONTROL from CBI: status = %d\n", rv);
+		return false;
+	}
+
+	return (cc.ucsi_enabled != 0);
+}
+
 static int cbi_get_string(char *buf, size_t bufsize, uint32_t tag)
 {
 	struct ec_params_get_cbi params = {
diff --git a/src/ec/google/chromeec/ec.h b/src/ec/google/chromeec/ec.h
index 0e1df9cf6a..0062df60db 100644
--- a/src/ec/google/chromeec/ec.h
+++ b/src/ec/google/chromeec/ec.h
@@ -424,6 +424,13 @@ void google_chromeec_clear_ec_ap_idle(void);
  */
 bool google_chromeec_is_battery_present_and_above_critical_threshold(void);
 
+/**
+ * Determine if the UCSI stack is currently active.
+ *
+ * @return true if EC implements the UCSI stack
+ */
+bool google_chromeec_get_ucsi_enabled(void);
+
 #if CONFIG(HAVE_ACPI_TABLES)
 /**
  * Writes USB Type-C PD related information to the SSDT
diff --git a/src/ec/google/chromeec/ec_acpi.c b/src/ec/google/chromeec/ec_acpi.c
index cf29636e34..e24f8ac824 100644
--- a/src/ec/google/chromeec/ec_acpi.c
+++ b/src/ec/google/chromeec/ec_acpi.c
@@ -157,6 +157,11 @@ static void fill_ssdt_typec_device(const struct device *dev)
 	struct acpi_pld pld = {0};
 	uint32_t pcap_mask = 0;
 
+	/* UCSI implementations do not require an ACPI device with mux info since the
+	   linux kernel doesn't set the muxes. */
+	if (google_chromeec_get_ucsi_enabled())
+		return;
+
 	rv = google_chromeec_get_num_pd_ports(&num_ports);
 	if (rv || num_ports == 0)
 		return;