mb/system76/lemp9: enable TPM

L140CU has a TPM2 connected via SPI. Add the TPM device to the
devicetree and enable it.

According to Intel doc#615170-001, PIRQ is required for SPI TPM to work.
Since the TPM is connected to GPP_A7, enable NF1 (PIRQA#) and set it as
TPM interrupt in Kconfig.

Note: The PCH maps either LPC TPM or SPI TPM to the same address and
handles either LPC or SPI communication transparently. Thus we can use
MAINBOARD_HAS_LPC_TPM here, which implements TPM via that address.

Tested, but only polling works currently, because there is some upstream
issue with the tpm_tis module in current Linux kernels. [1]

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1770021

Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Change-Id: I26d3b396fe1e99368e18fd3a6a9f02e3585b9f6e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43641
Reviewed-by:  Felix Singer <felixsinger@posteo.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/system76/lemp9/Kconfig

@@ -10,9 +10,8 @@ config BOARD_SPECIFIC_OPTIONS
 	select GENERIC_SPD_BIN
 	select INTEL_GMA_HAVE_VBT
 	select INTEL_LPSS_UART_FOR_CONSOLE
-# Chip select 2 is not yet supported by intel fast_spi
-#	select MAINBOARD_HAS_SPI_TPM_CR50
-#	select MAINBOARD_HAS_TPM2
+	select MAINBOARD_HAS_LPC_TPM
+	select MAINBOARD_HAS_TPM2
 	select NO_UART_ON_SUPERIO
 	select SOC_INTEL_COMETLAKE
 	select SOC_INTEL_COMMON_BLOCK_HDA
@@ -77,17 +76,12 @@ config VGA_BIOS_ID
 	string
 	default "8086,9b41"
 
+config TPM_PIRQ
+	hex
+	default 0x10 # GPP_A7/PIRQA#
+
 config POST_DEVICE
 	bool
 	default n
 
-# Chip select 2 is not yet supported by intel fast_spi
-#config DRIVER_TPM_SPI_BUS
-#	hex
-#	default 0x0
-#
-#config DRIVER_TPM_SPI_CHIP
-#	int
-#	default 2
-
 endif

src/mainboard/system76/lemp9/devicetree.cb

@@ -238,12 +238,16 @@ chip soc/intel/cannonlake
 		device pci 1e.1 off end # UART #1
 		device pci 1e.2 off end # GSPI #0
 		device pci 1e.3 off end # GSPI #1
-		device pci 1f.0 on  end # LPC Interface
+		device pci 1f.0 on	# LPC Interface
+			chip drivers/pc80/tpm	# TPM
+				device pnp 0c31.0 on  end
+			end
+		end
 		device pci 1f.1 off end # P2SB
 		device pci 1f.2 off end # Power Management Controller
 		device pci 1f.3 on  end # Intel HDA
 		device pci 1f.4 on  end # SMBus
-		device pci 1f.5 on  end # PCH SPI
+		device pci 1f.5 on  end	# PCH SPI
 		device pci 1f.6 off end # GbE
 	end
 end

src/mainboard/system76/lemp9/gpio.h

@@ -76,8 +76,8 @@ static const struct pad_config gpio_table[] = {
 		PAD_CFG_NF(GPP_A6, NONE, DEEP, NF1),
 
 	// GSPI0
-		// TODO - TPM_PIRQ#
-		PAD_CFG_NC(GPP_A7),
+		// PIRQA# / TPM_PIRQ#
+		PAD_CFG_NF(GPP_A7, NONE, DEEP, NF1),
 
 	// LPC
 		// PM_CLKRUN# with pull-up