Change in coreboot[master]: ec/lenovo/h8/acpi/thermal: Add coefficients for passive cooling

[Patrick Rudolph (Code Review)]

Patrick Rudolph has uploaded this change for review. ( https://review.coreboot.org/21223

Change subject: ec/lenovo/h8/acpi/thermal: Add coefficients for passive cooling
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ec/lenovo/h8/acpi/thermal: Add coefficients for passive cooling

The GNU/Linux kernel requires _TSP, _TC1, _TC2 and _PSL for passive cooling.
_TSP already has been added in a previous commit.
Copy the coefficients used on google devices to activate the feature and add
_PSL for SandyBridge and IvyBridge based Thinkpads.

On older Thinkpads the PPKG method needs to be implemented first.

Tested on Lenovo T430:
The CPU is throttled once the passive threshold has been reached.

Change-Id: I922923a9029de77158988ac254bab4aad9536935
Signed-off-by: Patrick Rudolph 
---
M src/ec/lenovo/h8/acpi/thermal.asl
1 file changed, 28 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/23/21223/1

diff --git a/src/ec/lenovo/h8/acpi/thermal.asl b/src/ec/lenovo/h8/acpi/thermal.asl
index 84e23f9..a40043c 100644
--- a/src/ec/lenovo/h8/acpi/thermal.asl
+++ b/src/ec/lenovo/h8/acpi/thermal.asl
@@ -40,6 +40,20 @@
    	/* Thermal sampling period for passive cooling: 10 seconds */
    	Name (_TSP, 100)

+		/* Coefficients for passive cooling */
+		Name (_TC1, 0x02)
+		Name (_TC2, 0x05)
+
+		/* FIXME: Add support for other CPUs as well */
+#if IS_ENABLED(CONFIG_CPU_INTEL_MODEL_206AX) || \
+	IS_ENABLED(CONFIG_CPU_INTEL_MODEL_306AX)
+		/* Processors used for passive cooling */
+		Method (_PSL, 0, Serialized)
+		{
+			Return (\PPKG ())
+		}
+#endif
+
    	Method(_CRT, 0, NotSerialized) {
    		Store (\TCRT, Local0)
    		if (LGreater(Local0, Zero)) {
@@ -76,6 +90,20 @@
    	/* Thermal sampling period for passive cooling: 10 seconds */
    	Name (_TSP, 100)

+		/* Coefficients for passive cooling */
+		Name (_TC1, 0x02)
+		Name (_TC2, 0x05)
+
+		/* FIXME: Add support for other CPUs as well */
+#if IS_ENABLED(CONFIG_CPU_INTEL_MODEL_206AX) || \
+	IS_ENABLED(CONFIG_CPU_INTEL_MODEL_306AX)
+		/* Processors used for passive cooling */
+		Method (_PSL, 0, Serialized)
+		{
+			Return (\PPKG ())
+		}
+#endif
+
    	Method(_CRT, 0, NotSerialized) {
    		Return (C2K(99))
    	}