nb/intel/sandybridge: Move southbridge code to bd82x6x

Move the southbridge code to bd82x6x folder similar to the lynxpoint
implementation.

Tested on Lenovo T520 (Intel Sandy Bridge).
Still boots to OS, no errors visible in dmesg.

Change-Id: I8afc9f966033f45823f5dfde279e0f66de165e93
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32035
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/northbridge/intel/sandybridge/early_init.c

@@ -27,20 +27,6 @@
 
 static void sandybridge_setup_bars(void)
 {
-	/* Setting up Southbridge. In the northbridge code. */
-	printk(BIOS_DEBUG, "Setting up static southbridge registers...");
-	pci_write_config32(PCH_LPC_DEV, RCBA, (uintptr_t)DEFAULT_RCBA | 1);
-
-	pci_write_config32(PCH_LPC_DEV, PMBASE, DEFAULT_PMBASE | 1);
-	pci_write_config8(PCH_LPC_DEV, ACPI_CNTL, 0x80); /* Enable ACPI BAR */
-
-	printk(BIOS_DEBUG, " done.\n");
-
-	printk(BIOS_DEBUG, "Disabling Watchdog reboot...");
-	RCBA32(GCS) = RCBA32(GCS) | (1 << 5);	/* No reset */
-	outw((1 << 11), DEFAULT_PMBASE | 0x60 | 0x08);	/* halt timer */
-	printk(BIOS_DEBUG, " done.\n");
-
 	printk(BIOS_DEBUG, "Setting up static northbridge registers...");
 	/* Set up all hardcoded northbridge BARs */
 	pci_write_config32(PCI_DEV(0, 0x00, 0), EPBAR, DEFAULT_EPBAR | 1);

src/northbridge/intel/sandybridge/romstage.c

@@ -28,10 +28,9 @@
 #include <device/device.h>
 #include <northbridge/intel/sandybridge/chip.h>
 #include <southbridge/intel/bd82x6x/pch.h>
-#include <southbridge/intel/common/gpio.h>
 #include <southbridge/intel/common/pmclib.h>
 
-static void early_pch_init(void)
+static void early_pch_reset_pmcon(void)
 {
 	u8 reg8;
 
@@ -56,13 +55,8 @@ void mainboard_romstage_entry(unsigned long bist)
 	if (bist == 0)
 		enable_lapic();
 
-	pch_enable_lpc();
-
-	/* Enable GPIOs */
-	pci_write_config32(PCH_LPC_DEV, GPIO_BASE, DEFAULT_GPIOBASE|1);
-	pci_write_config8(PCH_LPC_DEV, GPIO_CNTL, 0x10);
-
-	setup_pch_gpios(&mainboard_gpio_map);
+	/* Init LPC, GPIO, BARs, disable watchdog ... */
+	early_pch_init();
 
 	/* Initialize superio */
 	mainboard_config_superio();
@@ -101,7 +95,7 @@ void mainboard_romstage_entry(unsigned long bist)
 
 	post_code(0x3b);
 	/* Perform some initialization that must run before stage2 */
-	early_pch_init();
+	early_pch_reset_pmcon();
 	post_code(0x3c);
 
 	southbridge_configure_default_intmap();

src/southbridge/intel/bd82x6x/early_pch.c

@@ -18,6 +18,9 @@
 #include <arch/cbfs.h>
 #include <ip_checksum.h>
 #include <device/pci_def.h>
+#include <southbridge/intel/common/gpio.h>
+#include <southbridge/intel/common/pmbase.h>
+
 /* For DMI bar.  */
 #include <northbridge/intel/sandybridge/sandybridge.h>
 
@@ -367,3 +370,34 @@ early_pch_init_native (void)
 
 	init_dmi();
 }
+
+static void pch_enable_bars(void)
+{
+	pci_write_config32(PCH_LPC_DEV, RCBA, (uintptr_t)DEFAULT_RCBA | 1);
+
+	pci_write_config32(PCH_LPC_DEV, PMBASE, DEFAULT_PMBASE | 1);
+
+	pci_write_config8(PCH_LPC_DEV, ACPI_CNTL, 0x80);
+
+	pci_write_config32(PCH_LPC_DEV, GPIO_BASE, DEFAULT_GPIOBASE | 1);
+
+	/* Enable GPIO functionality. */
+	pci_write_config8(PCH_LPC_DEV, GPIO_CNTL, 0x10);
+}
+
+static void pch_generic_setup(void)
+{
+	RCBA32(GCS) = RCBA32(GCS) | (1 << 5);	/* No reset */
+	write_pmbase16(TCO1_CNT, 1 << 11);	/* halt timer */
+}
+
+void early_pch_init(void)
+{
+	pch_enable_lpc();
+
+	pch_enable_bars();
+
+	pch_generic_setup();
+
+	setup_pch_gpios(&mainboard_gpio_map);
+}

src/southbridge/intel/bd82x6x/pch.h

@@ -76,6 +76,7 @@ void southbridge_configure_default_intmap(void);
 void southbridge_rcba_config(void);
 void mainboard_rcba_config(void);
 void early_pch_init_native(void);
+void early_pch_init(void);
 
 struct southbridge_usb_port
 {