diff --git a/drivers/leds/simple/Kconfig b/drivers/leds/simple/Kconfig
index 9f6a68336659..9293e6b36c75 100644
--- a/drivers/leds/simple/Kconfig
+++ b/drivers/leds/simple/Kconfig
@@ -3,6 +3,7 @@ config LEDS_SIEMENS_SIMATIC_IPC
 	tristate "LED driver for Siemens Simatic IPCs"
 	depends on LEDS_CLASS
 	depends on SIEMENS_SIMATIC_IPC
+	select P2SB if X86
 	help
 	  This option enables support for the LEDs of several Industrial PCs
 	  from Siemens.
diff --git a/drivers/leds/simple/simatic-ipc-leds.c b/drivers/leds/simple/simatic-ipc-leds.c
index ff2c96e73241..215ef5b74236 100644
--- a/drivers/leds/simple/simatic-ipc-leds.c
+++ b/drivers/leds/simple/simatic-ipc-leds.c
@@ -15,6 +15,7 @@
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/platform_data/x86/p2sb.h>
 #include <linux/platform_data/x86/simatic-ipc-base.h>
 #include <linux/platform_device.h>
 #include <linux/sizes.h>
@@ -38,8 +39,8 @@ static struct simatic_ipc_led simatic_ipc_leds_io[] = {
 	{ }
 };
 
-/* the actual start will be discovered with PCI, 0 is a placeholder */
-struct resource simatic_ipc_led_mem_res = DEFINE_RES_MEM_NAMED(0, SZ_4K, KBUILD_MODNAME);
+/* the actual start will be discovered with p2sb, 0 is a placeholder */
+struct resource simatic_ipc_led_mem_res = DEFINE_RES_MEM_NAMED(0, 0, KBUILD_MODNAME);
 
 static void *simatic_ipc_led_memory;
 
@@ -143,14 +144,13 @@ static int simatic_ipc_leds_probe(struct platform_device *pdev)
 		ipcled = simatic_ipc_leds_mem;
 		type = IORESOURCE_MEM;
 
-		/* get GPIO base from PCI */
-		res->start = simatic_ipc_get_membase0(PCI_DEVFN(13, 0));
-		if (res->start == 0)
-			return -ENODEV;
+		err = p2sb_bar(NULL, 0, res);
+		if (err)
+			return err;
 
 		/* do the final address calculation */
 		res->start = res->start + (0xC5 << 16);
-		res->end += res->start;
+		res->end = res->start + SZ_4K - 1;
 
 		simatic_ipc_led_memory = devm_ioremap_resource(dev, res);
 		if (IS_ERR(simatic_ipc_led_memory))
diff --git a/drivers/platform/x86/simatic-ipc.c b/drivers/platform/x86/simatic-ipc.c
index b599cda5ba3c..26c35e1660cb 100644
--- a/drivers/platform/x86/simatic-ipc.c
+++ b/drivers/platform/x86/simatic-ipc.c
@@ -101,44 +101,6 @@ static int register_platform_devices(u32 station_id)
 	return 0;
 }
 
-/* FIXME: this should eventually be done with generic P2SB discovery code
- * the individual drivers for watchdogs and LEDs access memory that implements
- * GPIO, but pinctrl will not come up because of missing ACPI entries
- *
- * While there is no conflict a cleaner solution would be to somehow bring up
- * pinctrl even with these ACPI entries missing, and base the drivers on pinctrl.
- * After which the following function could be dropped, together with the code
- * poking the memory.
- */
-/*
- * Get membase address from PCI, used in leds and wdt module. Here we read
- * the bar0. The final address calculation is done in the appropriate modules
- */
-u32 simatic_ipc_get_membase0(unsigned int p2sb)
-{
-	struct pci_bus *bus;
-	u32 bar0 = 0;
-	/*
-	 * The GPIO memory is in bar0 of the hidden P2SB device.
-	 * Unhide the device to have a quick look at it, before we hide it
-	 * again.
-	 * Also grab the pci rescan lock so that device does not get discovered
-	 * and remapped while it is visible.
-	 * This code is inspired by drivers/mfd/lpc_ich.c
-	 */
-	bus = pci_find_bus(0, 0);
-	pci_lock_rescan_remove();
-	pci_bus_write_config_byte(bus, p2sb, 0xE1, 0x0);
-	pci_bus_read_config_dword(bus, p2sb, PCI_BASE_ADDRESS_0, &bar0);
-
-	bar0 &= ~0xf;
-	pci_bus_write_config_byte(bus, p2sb, 0xE1, 0x1);
-	pci_unlock_rescan_remove();
-
-	return bar0;
-}
-EXPORT_SYMBOL(simatic_ipc_get_membase0);
-
 static int __init simatic_ipc_init_module(void)
 {
 	const struct dmi_system_id *match;
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c8fa79da23b3..ce44a942fc68 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1628,6 +1628,7 @@ config SIEMENS_SIMATIC_IPC_WDT
 	tristate "Siemens Simatic IPC Watchdog"
 	depends on SIEMENS_SIMATIC_IPC
 	select WATCHDOG_CORE
+	select P2SB if X86
 	help
 	  This driver adds support for several watchdogs found in Industrial
 	  PCs from Siemens.
diff --git a/drivers/watchdog/simatic-ipc-wdt.c b/drivers/watchdog/simatic-ipc-wdt.c
index 8bac793c63fb..6599695dc672 100644
--- a/drivers/watchdog/simatic-ipc-wdt.c
+++ b/drivers/watchdog/simatic-ipc-wdt.c
@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/platform_data/x86/p2sb.h>
 #include <linux/platform_data/x86/simatic-ipc-base.h>
 #include <linux/platform_device.h>
 #include <linux/sizes.h>
@@ -54,9 +55,9 @@ static struct resource io_resource_trigger =
 	DEFINE_RES_IO_NAMED(WD_TRIGGER_IOADR, SZ_1,
 			    KBUILD_MODNAME " WD_TRIGGER_IOADR");
 
-/* the actual start will be discovered with pci, 0 is a placeholder */
+/* the actual start will be discovered with p2sb, 0 is a placeholder */
 static struct resource mem_resource =
-	DEFINE_RES_MEM_NAMED(0, SZ_4, "WD_RESET_BASE_ADR");
+	DEFINE_RES_MEM_NAMED(0, 0, "WD_RESET_BASE_ADR");
 
 static u32 wd_timeout_table[] = {2, 4, 6, 8, 16, 32, 48, 64 };
 static void __iomem *wd_reset_base_addr;
@@ -150,6 +151,7 @@ static int simatic_ipc_wdt_probe(struct platform_device *pdev)
 	struct simatic_ipc_platform *plat = pdev->dev.platform_data;
 	struct device *dev = &pdev->dev;
 	struct resource *res;
+	int ret;
 
 	switch (plat->devmode) {
 	case SIMATIC_IPC_DEVICE_227E:
@@ -190,15 +192,14 @@ static int simatic_ipc_wdt_probe(struct platform_device *pdev)
 	if (plat->devmode == SIMATIC_IPC_DEVICE_427E) {
 		res = &mem_resource;
 
-		/* get GPIO base from PCI */
-		res->start = simatic_ipc_get_membase0(PCI_DEVFN(0x1f, 1));
-		if (res->start == 0)
-			return -ENODEV;
+		ret = p2sb_bar(NULL, 0, res);
+		if (ret)
+			return ret;
 
 		/* do the final address calculation */
 		res->start = res->start + (GPIO_COMMUNITY0_PORT_ID << 16) +
 			     PAD_CFG_DW0_GPP_A_23;
-		res->end += res->start;
+		res->end = res->start + SZ_4 - 1;
 
 		wd_reset_base_addr = devm_ioremap_resource(dev, res);
 		if (IS_ERR(wd_reset_base_addr))
diff --git a/include/linux/platform_data/x86/simatic-ipc-base.h b/include/linux/platform_data/x86/simatic-ipc-base.h
index 62d2bc774067..39fefd48cf4d 100644
--- a/include/linux/platform_data/x86/simatic-ipc-base.h
+++ b/include/linux/platform_data/x86/simatic-ipc-base.h
@@ -24,6 +24,4 @@ struct simatic_ipc_platform {
 	u8	devmode;
 };
 
-u32 simatic_ipc_get_membase0(unsigned int p2sb);
-
 #endif /* __PLATFORM_DATA_X86_SIMATIC_IPC_BASE_H */
