[coreboot-gerrit] Change in coreboot[master]: soc/intel/tigerlake: Add USB4 _DSM for retimer firmware upgrade support

[John Zhao (Code Review)]

John Zhao has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/44347 )

Change subject: soc/intel/tigerlake: Add USB4 _DSM for retimer firmware upgrade support
......................................................................

soc/intel/tigerlake: Add USB4 _DSM for retimer firmware upgrade support

There is need to upgrade retimer firmware even if USB4 link is not up.
This change adds USB4 _DSM method to support retimer firmware upgrade.
The retimer force power GPIO state is queried and set accordingly.

BUG=b:162528868
TEST=Built and booted to kernel successfully on Volteer and TGLRVP.
TBD with kernel driver update to validate retimer firmware upgrade.

Signed-off-by: John Zhao 
Change-Id: I34006972124fa7b04380410669b0cb5051c4f518
---
M src/soc/intel/tigerlake/acpi/tcss_dma.asl
1 file changed, 75 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/47/44347/1

diff --git a/src/soc/intel/tigerlake/acpi/tcss_dma.asl b/src/soc/intel/tigerlake/acpi/tcss_dma.asl
index da2e8fe..39d55e9 100644
--- a/src/soc/intel/tigerlake/acpi/tcss_dma.asl
+++ b/src/soc/intel/tigerlake/acpi/tcss_dma.asl
@@ -105,7 +105,81 @@
    )
 }

+/*
+ * Retimer Device Specific Method
+ *
+ * Arg0: UUID (set to 61788900-c470-42bb-80f0-23a313864593)
+ * Arg1: Revision ID (set to 1)
+ * Arg2: Function Index
+ *       0: Query command implemented
+ *       1: Query force power enable state
+ *       2: Set force power state
+ *       0x3 - 0xffff: Reserved
+ * Arg3: A package containing parameters for the function specified
+ *       by the UUID, revsion ID and functon index.
+ */
 Method (_DSM, 4, Serialized)
 {
-	Return (Buffer() { 0 })
+	Name (PWR, 0)
+	If (Arg0 == ToUUID("61788900-c470-42bb-80f0-23a313864593")) {
+		switch (ToInteger(Arg2)) {
+			/*
+			 * Function Index: 0 - Standard query
+			 * Return: Bitmask of supported functions
+			 */
+			case (0) {
+				If (Arg1 == 1) {
+					/* Support all functions */
+					Return (Buffer() { 0x07 })
+				}
+
+				/* Only support query if unknown revision */
+				Return (Buffer() { 0x01 })
+			}
+
+			/*
+			 * Function Index: 1 - Query force power state
+			 * Arg3: Empty package
+			 * Return: 0 - if force power is disabled
+			 *         1 - if force power is enabled
+			 */
+			case (1) {
+				Return (PWR)
+			}
+
+			/*
+			 * Function Index: 2 - Set force power state
+			 * Arg3: A package consisting a single integer
+			 *       0: Turn off power
+			 *       1: Turn on powe
+			 * Return: 0
+			 */
+			case (2) {
+				CreateDWordField (Arg3, 0, CDW1)
+				If (CDW1 == PWR) {
+					/* Already in the state */
+					Return (0)
+				}
+
+				If (CDW1 == 0) {
+					/* Turn off power to the retimer */
+					CTXS(RT_FORCE_PWR)
+				} ElseIf (CDW1 == 1) {
+					/* Turn on power to the retimer */
+					STXS(RT_FORCE_PWR)
+				} Else {
+					Return (0)
+				}
+
+				PWR = CDW1
+				Return (0)
+			}
+
+			Default {
+				Return (Buffer() { 0 })
+			}
+		}
+	} Else {
+		Return (Buffer() { 0 })
+	}
 }