ec/google/chromeec: Do not fill TypeC ACPI device when UCSI is enabled

Do not fill the ACPI table entry associated with the cros_ec_typec
driver once we switch to the UCSI kernel driver. Skip the ACPI entry if
EC implements the UCSI_PPM feature, and the CBI flag to enable UCSI is
set.

BUG=b:333078787
TEST=emerge-brox coreboot chromeos-bootimage

Cq-Depend: chromium:5416841
Change-Id: I67dff6445aa7ba3ba48a04d1df3541f880d09d0a
Signed-off-by: Pavan Holla <pholla@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81967
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Caveh Jalali <caveh@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>

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;