[XS] Change in coreboot[main]: mb/google/brya/var/mithrax: Enable RTD3 for SSD to resolve S0ix issue

[Subrata Banik (Code Review)]

Subrata Banik has submitted this change. ( https://review.coreboot.org/c/coreboot/+/87060?usp=email )

Change subject: mb/google/brya/var/mithrax: Enable RTD3 for SSD to resolve S0ix issue
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mb/google/brya/var/mithrax: Enable RTD3 for SSD to resolve S0ix issue

Some SSDs block the CPU from reaching C10 during the S0ix suspend
without the RTD3 configuration. Add PCIe RTD3 support so NVMe gets
placed into D3 state when entering S0ix.

Enable and reset GPIOs are configured as per pin mapping in gpio.c.

BUG=b:391612392
TEST=Run suspend_stress_test on mithrax device and verify that the
device suspends to S0ix.

Change-Id: I5008ec5e153c3695b1d6aa1183515eba192deaa2
Signed-off-by: Pranava Y N 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/87060
Reviewed-by: Eric Lai 
Tested-by: build bot (Jenkins) 
Reviewed-by: Kapil Porwal 
Reviewed-by: Subrata Banik 
Reviewed-by: Jayvik Desai 
---
M src/mainboard/google/brya/variants/mithrax/overridetree.cb
1 file changed, 9 insertions(+), 0 deletions(-)

Approvals:
  Jayvik Desai: Looks good to me, approved
  build bot (Jenkins): Verified
  Kapil Porwal: Looks good to me, approved
  Subrata Banik: Looks good to me, approved
  Eric Lai: Looks good to me, approved

diff --git a/src/mainboard/google/brya/variants/mithrax/overridetree.cb b/src/mainboard/google/brya/variants/mithrax/overridetree.cb
index 15bebe2..6a85edf 100644
--- a/src/mainboard/google/brya/variants/mithrax/overridetree.cb
+++ b/src/mainboard/google/brya/variants/mithrax/overridetree.cb
@@ -218,6 +218,15 @@
    			device generic 0 on end
    		end
    	end	#PCIE8 SD card
+		device ref pcie_rp9 on
+			chip soc/intel/common/block/pcie/rtd3
+				register "is_storage" = "true"
+				register "enable_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPP_D11)"
+				register "reset_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_B4)"
+				register "srcclk_pin" = "1"
+				device generic 0 on end
+			end
+		end	#PCIE9-12 SSD
    	device ref i2c0 on
    		chip drivers/i2c/generic
    			register "hid" = ""RTL5682""