mb/ocp/deltalake: Config PCH PCIe ports in devicetree

Tested on OCP Delta Lake with lspci checking if PCIe speed is changed
are expected.

Change-Id: I189027c403814d68db2b7c5f41fc254a293fe3a1
Signed-off-by: Morgan Jang <Morgan_Jang@wiwynn.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41690
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Maxim Polyakov <max.senia.poliak@gmail.com>

src/mainboard/ocp/deltalake/devicetree.cb

@@ -39,6 +39,12 @@ chip soc/intel/xeon_sp/cpx
 	register "gen1_dec" = "0x00fc0601" # BIC in-band update support
 	register "gen2_dec" = "0x000c0ca1" # IPMI KCS
 
+	# configure PCH PCIe port
+	register "pch_pci_port[8]" = "{
+		.ForceEnable = 0x1,
+		.PortLinkSpeed = PcieAuto,
+	}"
+
 	device cpu_cluster 0 on
 	  device lapic 0 on end
 	end

src/mainboard/ocp/deltalake/romstage.c

@@ -7,6 +7,7 @@
 #include <FspmUpd.h>
 #include <soc/romstage.h>
 
+#include "chip.h"
 #include "ipmi.h"
 #include "vpd.h"
 
@@ -74,7 +75,21 @@ static void mainboard_config_gpios(FSPM_UPD *mupd)
 
 static void mainboard_config_iio(FSPM_UPD *mupd)
 {
+	uint8_t index;
+	const config_t *config = config_of_soc();
+
 	oem_update_iio(mupd);
+
+	for (index = 0; index < MAX_PCH_PCIE_PORT; index++) {
+		mupd->FspmConfig.PchPcieForceEnable[index] =
+			config->pch_pci_port[index].ForceEnable;
+		mupd->FspmConfig.PchPciePortLinkSpeed[index] =
+			config->pch_pci_port[index].PortLinkSpeed;
+	}
+
+	mupd->FspmConfig.PchPcieRootPortFunctionSwap = 0x00;
+	/* The default value is 0XFF in FSP, set it to 0xFE by platform */
+	mupd->FspmConfig.PchPciePllSsc = 0xFE;
 }
 
 void mainboard_memory_init_params(FSPM_UPD *mupd)

src/soc/intel/xeon_sp/cpx/chip.h

@@ -7,10 +7,35 @@
 #include <soc/irq.h>
 #include <stdint.h>
 
+#define MAX_PCH_PCIE_PORT   20
+
+/**
+ UPD_PCH_PCIE_PORT:
+ ForceEnable           -  Enable/Disable PCH PCIe port
+ PortLinkSpeed         -  Port Link Speed. Use PCIE_LINK_SPEED to set
+**/
+struct pch_pcie_port {
+	uint8_t    ForceEnable;
+	uint8_t    PortLinkSpeed;
+};
+
+/**
+ PCIe Link Speed Selection
+ **/
+typedef enum {
+	PcieAuto = 0,
+	PcieGen1,
+	PcieGen2,
+	PcieGen3
+} pcie_link_speed;
+
 struct soc_intel_xeon_sp_cpx_config {
 	/* Common struct containing soc config data required by common code */
 	struct soc_intel_common_config common_soc_config;
 
+	/* Struct for configuring PCH PCIe port */
+	struct pch_pcie_port pch_pci_port[MAX_PCH_PCIE_PORT];
+
 	/**
 	 * Interrupt Routing configuration
 	 * If bit7 is 1, the interrupt is disabled.