Merge tag 'ib-mfd-edac-i2c-leds-pinctrl-platform-watchdog-v5.20' into review-hans

Immutable branch between MFD, EDAC, I2C, LEDs, PinCtrl, Platform and Watchdog due for the v5.20 merge window

4 files changed, 151 insertions, 39 deletions

diff --git a/drivers/platform/x86/intel/Kconfig b/drivers/platform/x86/intel/Kconfig
index 794968bda115..c9cfbaae436b 100644
--- a/drivers/platform/x86/intel/Kconfig
+++ b/drivers/platform/x86/intel/Kconfig
@@ -70,6 +70,18 @@ config INTEL_OAKTRAIL
 	  enable/disable the Camera, WiFi, BT etc. devices. If in doubt, say Y
 	  here; it will only load on supported platforms.
 
+config P2SB
+	bool "Primary to Sideband (P2SB) bridge access support"
+	depends on PCI
+	help
+	  The Primary to Sideband (P2SB) bridge is an interface to some
+	  PCI devices connected through it. In particular, SPI NOR controller
+	  in Intel Apollo Lake SoC is one of such devices.
+
+	  The main purpose of this library is to unhide P2SB device in case
+	  firmware kept it hidden on some platforms in order to access devices
+	  behind it.
+
 config INTEL_BXTWC_PMIC_TMU
 	tristate "Intel Broxton Whiskey Cove TMU Driver"
 	depends on INTEL_SOC_PMIC_BXTWC
diff --git a/drivers/platform/x86/intel/Makefile b/drivers/platform/x86/intel/Makefile
index 717933dd0cfd..741a9404db98 100644
--- a/drivers/platform/x86/intel/Makefile
+++ b/drivers/platform/x86/intel/Makefile
@@ -28,6 +28,8 @@ intel_int0002_vgpio-y			:= int0002_vgpio.o
 obj-$(CONFIG_INTEL_INT0002_VGPIO)	+= intel_int0002_vgpio.o
 intel_oaktrail-y			:= oaktrail.o
 obj-$(CONFIG_INTEL_OAKTRAIL)		+= intel_oaktrail.o
+intel_p2sb-y				:= p2sb.o
+obj-$(CONFIG_P2SB)			+= intel_p2sb.o
 intel_sdsi-y				:= sdsi.o
 obj-$(CONFIG_INTEL_SDSI)		+= intel_sdsi.o
 intel_vsec-y				:= vsec.o
diff --git a/drivers/platform/x86/intel/p2sb.c b/drivers/platform/x86/intel/p2sb.c
new file mode 100644
index 000000000000..fb2e141f3eb8
--- /dev/null
+++ b/drivers/platform/x86/intel/p2sb.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Primary to Sideband (P2SB) bridge access support
+ *
+ * Copyright (c) 2017, 2021-2022 Intel Corporation.
+ *
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *	    Jonathan Yong <jonathan.yong@intel.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/export.h>
+#include <linux/pci.h>
+#include <linux/platform_data/x86/p2sb.h>
+
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+
+#define P2SBC			0xe0
+#define P2SBC_HIDE		BIT(8)
+
+static const struct x86_cpu_id p2sb_cpu_ids[] = {
+	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT,	PCI_DEVFN(13, 0)),
+	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_D,	PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_D,	PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE,		PCI_DEVFN(31, 1)),
+	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L,		PCI_DEVFN(31, 1)),
+	{}
+};
+
+static int p2sb_get_devfn(unsigned int *devfn)
+{
+	const struct x86_cpu_id *id;
+
+	id = x86_match_cpu(p2sb_cpu_ids);
+	if (!id)
+		return -ENODEV;
+
+	*devfn = (unsigned int)id->driver_data;
+	return 0;
+}
+
+static int p2sb_read_bar0(struct pci_dev *pdev, struct resource *mem)
+{
+	/* Copy resource from the first BAR of the device in question */
+	*mem = pdev->resource[0];
+	return 0;
+}
+
+static int p2sb_scan_and_read(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
+{
+	struct pci_dev *pdev;
+	int ret;
+
+	pdev = pci_scan_single_device(bus, devfn);
+	if (!pdev)
+		return -ENODEV;
+
+	ret = p2sb_read_bar0(pdev, mem);
+
+	pci_stop_and_remove_bus_device(pdev);
+	return ret;
+}
+
+/**
+ * p2sb_bar - Get Primary to Sideband (P2SB) bridge device BAR
+ * @bus: PCI bus to communicate with
+ * @devfn: PCI slot and function to communicate with
+ * @mem: memory resource to be filled in
+ *
+ * The BIOS prevents the P2SB device from being enumerated by the PCI
+ * subsystem, so we need to unhide and hide it back to lookup the BAR.
+ *
+ * if @bus is NULL, the bus 0 in domain 0 will be used.
+ * If @devfn is 0, it will be replaced by devfn of the P2SB device.
+ *
+ * Caller must provide a valid pointer to @mem.
+ *
+ * Locking is handled by pci_rescan_remove_lock mutex.
+ *
+ * Return:
+ * 0 on success or appropriate errno value on error.
+ */
+int p2sb_bar(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
+{
+	struct pci_dev *pdev_p2sb;
+	unsigned int devfn_p2sb;
+	u32 value = P2SBC_HIDE;
+	int ret;
+
+	/* Get devfn for P2SB device itself */
+	ret = p2sb_get_devfn(&devfn_p2sb);
+	if (ret)
+		return ret;
+
+	/* if @bus is NULL, use bus 0 in domain 0 */
+	bus = bus ?: pci_find_bus(0, 0);
+
+	/*
+	 * Prevent concurrent PCI bus scan from seeing the P2SB device and
+	 * removing via sysfs while it is temporarily exposed.
+	 */
+	pci_lock_rescan_remove();
+
+	/* Unhide the P2SB device, if needed */
+	pci_bus_read_config_dword(bus, devfn_p2sb, P2SBC, &value);
+	if (value & P2SBC_HIDE)
+		pci_bus_write_config_dword(bus, devfn_p2sb, P2SBC, 0);
+
+	pdev_p2sb = pci_scan_single_device(bus, devfn_p2sb);
+	if (devfn)
+		ret = p2sb_scan_and_read(bus, devfn, mem);
+	else
+		ret = p2sb_read_bar0(pdev_p2sb, mem);
+	pci_stop_and_remove_bus_device(pdev_p2sb);
+
+	/* Hide the P2SB device, if it was hidden */
+	if (value & P2SBC_HIDE)
+		pci_bus_write_config_dword(bus, devfn_p2sb, P2SBC, P2SBC_HIDE);
+
+	pci_unlock_rescan_remove();
+
+	if (ret)
+		return ret;
+
+	if (mem->flags == 0)
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(p2sb_bar);
diff --git a/drivers/platform/x86/simatic-ipc.c b/drivers/platform/x86/simatic-ipc.c
index b599cda5ba3c..ca3647b751d5 100644
--- a/drivers/platform/x86/simatic-ipc.c
+++ b/drivers/platform/x86/simatic-ipc.c
@@ -51,6 +51,7 @@ static int register_platform_devices(u32 station_id)
 {
 	u8 ledmode = SIMATIC_IPC_DEVICE_NONE;
 	u8 wdtmode = SIMATIC_IPC_DEVICE_NONE;
+	char *pdevname = KBUILD_MODNAME "_leds";
 	int i;
 
 	platform_data.devmode = SIMATIC_IPC_DEVICE_NONE;
@@ -64,10 +65,12 @@ static int register_platform_devices(u32 station_id)
 	}
 
 	if (ledmode != SIMATIC_IPC_DEVICE_NONE) {
+		if (ledmode == SIMATIC_IPC_DEVICE_127E)
+			pdevname = KBUILD_MODNAME "_leds_gpio";
 		platform_data.devmode = ledmode;
 		ipc_led_platform_device =
 			platform_device_register_data(NULL,
-				KBUILD_MODNAME "_leds", PLATFORM_DEVID_NONE,
+				pdevname, PLATFORM_DEVID_NONE,
 				&platform_data,
 				sizeof(struct simatic_ipc_platform));
 		if (IS_ERR(ipc_led_platform_device))
@@ -101,44 +104,6 @@ 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;