[S] Change in coreboot[main]: mb/google/dedede/var/galtic: Add fw_config option for touchpad type

[Matt DeVillier (Code Review)]

Matt DeVillier has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/83606?usp=email )

Change subject: mb/google/dedede/var/galtic: Add fw_config option for touchpad type
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mb/google/dedede/var/galtic: Add fw_config option for touchpad type

Galtic has two Elan touchpad options, and since both use the same i2c
address, the runtime i2c detection performed during SSDT generation
can't distinquish between them, leading to both devices being added
to the SSDT. This isn't a problem for Linux, but Windows can't
deal with two touchpads being enabled and using the same resources.

To mitigate this, add a new fw_config field which allows selection
between the two touchpad models, as well as a fallback option for
all devices which are not configured. Users who need to can set the
touchpad type in the SSFC using ectool, and then coreboot will
enable only the selected touchpad at boot.

TEST=build/boot google/dedede (galnat) after setting touchpad type
in SSFC. Verify correct touchpad selected via fw_config, only one
touchpad entry present in SSDT, and touchpad functional under both
Linux and Windows 11.

Change-Id: I36797eb5c8f262782380f95ff3c2e38443cf00c0
Signed-off-by: Matt DeVillier 
---
M src/mainboard/google/dedede/variants/galtic/overridetree.cb
1 file changed, 13 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/06/83606/1

diff --git a/src/mainboard/google/dedede/variants/galtic/overridetree.cb b/src/mainboard/google/dedede/variants/galtic/overridetree.cb
index 51d5a7a..86c9bae 100644
--- a/src/mainboard/google/dedede/variants/galtic/overridetree.cb
+++ b/src/mainboard/google/dedede/variants/galtic/overridetree.cb
@@ -9,6 +9,11 @@
    	option AUDIO_CODEC_ALC5682 1
    	option AUDIO_CODEC_ALC5682I_VS 2
    end
+	field TOUCHPAD_SOURCE 44 45
+		option TOUCHPAD_UNPROVISIONED 0
+		option TOUCHPAD_ELAN0000 1
+		option TOUCHPAD_ELAN2702 2
+	end
 end

chip soc/intel/jasperlake
@@ -144,7 +149,10 @@
    			register "irq" = "ACPI_IRQ_WAKE_EDGE_LOW(GPP_B3_IRQ)"
    			register "wake" = "GPE0_DW0_03"
    			register "detect" = "1"
-				device i2c 15 on end
+				device i2c 15 on
+					probe TOUCHPAD_SOURCE TOUCHPAD_UNPROVISIONED
+					probe TOUCHPAD_SOURCE TOUCHPAD_ELAN0000
+				end
    		end
    		chip drivers/i2c/hid
    			register "generic.hid" = ""ELAN2702""
@@ -153,7 +161,10 @@
    			register "generic.wake" = "GPE0_DW0_03"
    			register "generic.detect" = "1"
    			register "hid_desc_reg_offset" = "0x01"
-				device i2c 15 on end
+				device i2c 15 on
+					probe TOUCHPAD_SOURCE TOUCHPAD_UNPROVISIONED
+					probe TOUCHPAD_SOURCE TOUCHPAD_ELAN2702
+				end
    		end
    	end
    	device pci 15.2 on