Merge tag 'ib-mfd-mtd-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd

From Lee Jones:

"""
Immutable branch between MFD and MTD due for the v4.11 merge window
"""

Documentation/mtd/intel-spi.txt

+Upgrading BIOS using intel-spi
+------------------------------
+
+Many Intel CPUs like Baytrail and Braswell include SPI serial flash host
+controller which is used to hold BIOS and other platform specific data.
+Since contents of the SPI serial flash is crucial for machine to function,
+it is typically protected by different hardware protection mechanisms to
+avoid accidental (or on purpose) overwrite of the content.
+
+Not all manufacturers protect the SPI serial flash, mainly because it
+allows upgrading the BIOS image directly from an OS.
+
+The intel-spi driver makes it possible to read and write the SPI serial
+flash, if certain protection bits are not set and locked. If it finds
+any of them set, the whole MTD device is made read-only to prevent
+partial overwrites. By default the driver exposes SPI serial flash
+contents as read-only but it can be changed from kernel command line,
+passing "intel-spi.writeable=1".
+
+Please keep in mind that overwriting the BIOS image on SPI serial flash
+might render the machine unbootable and requires special equipment like
+Dediprog to revive. You have been warned!
+
+Below are the steps how to upgrade MinnowBoard MAX BIOS directly from
+Linux.
+
+ 1) Download and extract the latest Minnowboard MAX BIOS SPI image
+    [1]. At the time writing this the latest image is v92.
+
+ 2) Install mtd-utils package [2]. We need this in order to erase the SPI
+    serial flash. Distros like Debian and Fedora have this prepackaged with
+    name "mtd-utils".
+
+ 3) Add "intel-spi.writeable=1" to the kernel command line and reboot
+    the board (you can also reload the driver passing "writeable=1" as
+    module parameter to modprobe).
+
+ 4) Once the board is up and running again, find the right MTD partition
+    (it is named as "BIOS"):
+
+    # cat /proc/mtd
+    dev:    size   erasesize  name
+    mtd0: 00800000 00001000 "BIOS"
+
+    So here it will be /dev/mtd0 but it may vary.
+
+ 5) Make backup of the existing image first:
+
+    # dd if=/dev/mtd0ro of=bios.bak
+    16384+0 records in
+    16384+0 records out
+    8388608 bytes (8.4 MB) copied, 10.0269 s, 837 kB/s
+
+ 6) Verify the backup
+
+    # sha1sum /dev/mtd0ro bios.bak
+    fdbb011920572ca6c991377c4b418a0502668b73  /dev/mtd0ro
+    fdbb011920572ca6c991377c4b418a0502668b73  bios.bak
+
+    The SHA1 sums must match. Otherwise do not continue any further!
+
+ 7) Erase the SPI serial flash. After this step, do not reboot the
+    board! Otherwise it will not start anymore.
+
+    # flash_erase /dev/mtd0 0 0
+    Erasing 4 Kibyte @ 7ff000 -- 100 % complete
+
+ 8) Once completed without errors you can write the new BIOS image:
+
+    # dd if=MNW2MAX1.X64.0092.R01.1605221712.bin of=/dev/mtd0
+
+ 9) Verify that the new content of the SPI serial flash matches the new
+    BIOS image:
+
+    # sha1sum /dev/mtd0ro MNW2MAX1.X64.0092.R01.1605221712.bin
+    9b4df9e4be2057fceec3a5529ec3d950836c87a2  /dev/mtd0ro
+    9b4df9e4be2057fceec3a5529ec3d950836c87a2 MNW2MAX1.X64.0092.R01.1605221712.bin
+
+    The SHA1 sums should match.
+
+ 10) Now you can reboot your board and observe the new BIOS starting up
+     properly.
+
+References
+----------
+
+[1] https://firmware.intel.com/sites/default/files/MinnowBoard.MAX_.X64.92.R01.zip
+[2] http://www.linux-mtd.infradead.org/

drivers/mfd/lpc_ich.c

@@ -56,6 +56,7 @@
  *	document number TBD : Wildcat Point-LP
  *	document number TBD : 9 Series
  *	document number TBD : Lewisburg
+ *	document number TBD : Apollo Lake SoC
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -83,6 +84,17 @@
 #define ACPIBASE_GCS_OFF	0x3410
 #define ACPIBASE_GCS_END	0x3414
 
+#define SPIBASE_BYT		0x54
+#define SPIBASE_BYT_SZ		512
+#define SPIBASE_BYT_EN		BIT(1)
+
+#define SPIBASE_LPT		0x3800
+#define SPIBASE_LPT_SZ		512
+#define BCR			0xdc
+#define BCR_WPD			BIT(0)
+
+#define SPIBASE_APL_SZ		4096
+
 #define GPIOBASE_ICH0		0x58
 #define GPIOCTRL_ICH0		0x5C
 #define GPIOBASE_ICH6		0x48
@@ -133,6 +145,12 @@ static struct resource gpio_ich_res[] = {
 	},
 };
 
+static struct resource intel_spi_res[] = {
+	{
+		.flags = IORESOURCE_MEM,
+	}
+};
+
 static struct mfd_cell lpc_ich_wdt_cell = {
 	.name = "iTCO_wdt",
 	.num_resources = ARRAY_SIZE(wdt_ich_res),
@@ -147,6 +165,14 @@ static struct mfd_cell lpc_ich_gpio_cell = {
 	.ignore_resource_conflicts = true,
 };
 
+
+static struct mfd_cell lpc_ich_spi_cell = {
+	.name = "intel-spi",
+	.num_resources = ARRAY_SIZE(intel_spi_res),
+	.resources = intel_spi_res,
+	.ignore_resource_conflicts = true,
+};
+
 /* chipset related info */
 enum lpc_chipsets {
 	LPC_ICH = 0,	/* ICH */
@@ -216,6 +242,7 @@ enum lpc_chipsets {
 	LPC_BRASWELL,	/* Braswell SoC */
 	LPC_LEWISBURG,	/* Lewisburg */
 	LPC_9S,		/* 9 Series */
+	LPC_APL,	/* Apollo Lake SoC */
 };
 
 static struct lpc_ich_info lpc_chipset_info[] = {
@@ -494,10 +521,12 @@ static struct lpc_ich_info lpc_chipset_info[] = {
 		.name = "Lynx Point",
 		.iTCO_version = 2,
 		.gpio_version = ICH_V5_GPIO,
+		.spi_type = INTEL_SPI_LPT,
 	},
 	[LPC_LPT_LP] = {
 		.name = "Lynx Point_LP",
 		.iTCO_version = 2,
+		.spi_type = INTEL_SPI_LPT,
 	},
 	[LPC_WBG] = {
 		.name = "Wellsburg",
@@ -511,6 +540,7 @@ static struct lpc_ich_info lpc_chipset_info[] = {
 	[LPC_BAYTRAIL] = {
 		.name = "Bay Trail SoC",
 		.iTCO_version = 3,
+		.spi_type = INTEL_SPI_BYT,
 	},
 	[LPC_COLETO] = {
 		.name = "Coleto Creek",
@@ -519,10 +549,12 @@ static struct lpc_ich_info lpc_chipset_info[] = {
 	[LPC_WPT_LP] = {
 		.name = "Wildcat Point_LP",
 		.iTCO_version = 2,
+		.spi_type = INTEL_SPI_LPT,
 	},
 	[LPC_BRASWELL] = {
 		.name = "Braswell SoC",
 		.iTCO_version = 3,
+		.spi_type = INTEL_SPI_BYT,
 	},
 	[LPC_LEWISBURG] = {
 		.name = "Lewisburg",
@@ -533,6 +565,10 @@ static struct lpc_ich_info lpc_chipset_info[] = {
 		.iTCO_version = 2,
 		.gpio_version = ICH_V5_GPIO,
 	},
+	[LPC_APL] = {
+		.name = "Apollo Lake SoC",
+		.spi_type = INTEL_SPI_BXT,
+	},
 };
 
 /*
@@ -681,6 +717,7 @@ static const struct pci_device_id lpc_ich_ids[] = {
 	{ PCI_VDEVICE(INTEL, 0x3b14), LPC_3420},
 	{ PCI_VDEVICE(INTEL, 0x3b16), LPC_3450},
 	{ PCI_VDEVICE(INTEL, 0x5031), LPC_EP80579},
+	{ PCI_VDEVICE(INTEL, 0x5ae8), LPC_APL},
 	{ PCI_VDEVICE(INTEL, 0x8c40), LPC_LPT},
 	{ PCI_VDEVICE(INTEL, 0x8c41), LPC_LPT},
 	{ PCI_VDEVICE(INTEL, 0x8c42), LPC_LPT},
@@ -1056,6 +1093,94 @@ static int lpc_ich_init_wdt(struct pci_dev *dev)
 	return ret;
 }
 
+static int lpc_ich_init_spi(struct pci_dev *dev)
+{
+	struct lpc_ich_priv *priv = pci_get_drvdata(dev);
+	struct resource *res = &intel_spi_res[0];
+	struct intel_spi_boardinfo *info;
+	u32 spi_base, rcba, bcr;
+
+	info = devm_kzalloc(&dev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->type = lpc_chipset_info[priv->chipset].spi_type;
+
+	switch (info->type) {
+	case INTEL_SPI_BYT:
+		pci_read_config_dword(dev, SPIBASE_BYT, &spi_base);
+		if (spi_base & SPIBASE_BYT_EN) {
+			res->start = spi_base & ~(SPIBASE_BYT_SZ - 1);
+			res->end = res->start + SPIBASE_BYT_SZ - 1;
+		}
+		break;
+
+	case INTEL_SPI_LPT:
+		pci_read_config_dword(dev, RCBABASE, &rcba);
+		if (rcba & 1) {
+			spi_base = round_down(rcba, SPIBASE_LPT_SZ);
+			res->start = spi_base + SPIBASE_LPT;
+			res->end = res->start + SPIBASE_LPT_SZ - 1;
+
+			/*
+			 * Try to make the flash chip writeable now by
+			 * setting BCR_WPD. It it fails we tell the driver
+			 * that it can only read the chip.
+			 */
+			pci_read_config_dword(dev, BCR, &bcr);
+			if (!(bcr & BCR_WPD)) {
+				bcr |= BCR_WPD;
+				pci_write_config_dword(dev, BCR, bcr);
+				pci_read_config_dword(dev, BCR, &bcr);
+			}
+			info->writeable = !!(bcr & BCR_WPD);
+		}
+		break;
+
+	case INTEL_SPI_BXT: {
+		unsigned int p2sb = PCI_DEVFN(13, 0);
+		unsigned int spi = PCI_DEVFN(13, 2);
+		struct pci_bus *bus = dev->bus;
+
+		/*
+		 * The P2SB is hidden by BIOS and we need to unhide it in
+		 * order to read BAR of the SPI flash device. Once that is
+		 * done we hide it again.
+		 */
+		pci_bus_write_config_byte(bus, p2sb, 0xe1, 0x0);
+		pci_bus_read_config_dword(bus, spi, PCI_BASE_ADDRESS_0,
+					  &spi_base);
+		if (spi_base != ~0) {
+			res->start = spi_base & 0xfffffff0;
+			res->end = res->start + SPIBASE_APL_SZ - 1;
+
+			pci_bus_read_config_dword(bus, spi, BCR, &bcr);
+			if (!(bcr & BCR_WPD)) {
+				bcr |= BCR_WPD;
+				pci_bus_write_config_dword(bus, spi, BCR, bcr);
+				pci_bus_read_config_dword(bus, spi, BCR, &bcr);
+			}
+			info->writeable = !!(bcr & BCR_WPD);
+		}
+
+		pci_bus_write_config_byte(bus, p2sb, 0xe1, 0x1);
+		break;
+	}
+
+	default:
+		return -EINVAL;
+	}
+
+	if (!res->start)
+		return -ENODEV;
+
+	lpc_ich_spi_cell.platform_data = info;
+	lpc_ich_spi_cell.pdata_size = sizeof(*info);
+
+	return mfd_add_devices(&dev->dev, PLATFORM_DEVID_NONE,
+			       &lpc_ich_spi_cell, 1, NULL, 0, NULL);
+}
+
 static int lpc_ich_probe(struct pci_dev *dev,
 				const struct pci_device_id *id)
 {
@@ -1099,6 +1224,12 @@ static int lpc_ich_probe(struct pci_dev *dev,
 			cell_added = true;
 	}
 
+	if (lpc_chipset_info[priv->chipset].spi_type) {
+		ret = lpc_ich_init_spi(dev);
+		if (!ret)
+			cell_added = true;
+	}
+
 	/*
 	 * We only care if at least one or none of the cells registered
 	 * successfully.

drivers/mtd/spi-nor/Kconfig

@@ -86,4 +86,24 @@ config SPI_NXP_SPIFI
 	  Flash. Enable this option if you have a device with a SPIFI
 	  controller and want to access the Flash as a mtd device.
 
+config SPI_INTEL_SPI
+	tristate
+
+config SPI_INTEL_SPI_PLATFORM
+	tristate "Intel PCH/PCU SPI flash platform driver" if EXPERT
+	depends on X86
+	select SPI_INTEL_SPI
+	help
+	  This enables platform support for the Intel PCH/PCU SPI
+	  controller in master mode. This controller is present in modern
+	  Intel hardware and is used to hold BIOS and other persistent
+	  settings. Using this driver it is possible to upgrade BIOS
+	  directly from Linux.
+
+	  Say N here unless you know what you are doing. Overwriting the
+	  SPI flash may render the system unbootable.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called intel-spi-platform.
+
 endif # MTD_SPI_NOR

drivers/mtd/spi-nor/Makefile

@@ -6,3 +6,5 @@ obj-$(CONFIG_SPI_FSL_QUADSPI)	+= fsl-quadspi.o
 obj-$(CONFIG_SPI_HISI_SFC)	+= hisi-sfc.o
 obj-$(CONFIG_MTD_MT81xx_NOR)    += mtk-quadspi.o
 obj-$(CONFIG_SPI_NXP_SPIFI)	+= nxp-spifi.o
+obj-$(CONFIG_SPI_INTEL_SPI)	+= intel-spi.o
+obj-$(CONFIG_SPI_INTEL_SPI_PLATFORM)	+= intel-spi-platform.o

drivers/mtd/spi-nor/intel-spi-platform.c

+/*
+ * Intel PCH/PCU SPI flash platform driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "intel-spi.h"
+
+static int intel_spi_platform_probe(struct platform_device *pdev)
+{
+	struct intel_spi_boardinfo *info;
+	struct intel_spi *ispi;
+	struct resource *mem;
+
+	info = dev_get_platdata(&pdev->dev);
+	if (!info)
+		return -EINVAL;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ispi = intel_spi_probe(&pdev->dev, mem, info);
+	if (IS_ERR(ispi))
+		return PTR_ERR(ispi);
+
+	platform_set_drvdata(pdev, ispi);
+	return 0;
+}
+
+static int intel_spi_platform_remove(struct platform_device *pdev)
+{
+	struct intel_spi *ispi = platform_get_drvdata(pdev);
+
+	return intel_spi_remove(ispi);
+}
+
+static struct platform_driver intel_spi_platform_driver = {
+	.probe = intel_spi_platform_probe,
+	.remove = intel_spi_platform_remove,
+	.driver = {
+		.name = "intel-spi",
+	},
+};
+
+module_platform_driver(intel_spi_platform_driver);
+
+MODULE_DESCRIPTION("Intel PCH/PCU SPI flash platform driver");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:intel-spi");

drivers/mtd/spi-nor/intel-spi.c

+/*
+ * Intel PCH/PCU SPI flash driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+#include <linux/platform_data/intel-spi.h>
+
+#include "intel-spi.h"
+
+/* Offsets are from @ispi->base */
+#define BFPREG				0x00
+
+#define HSFSTS_CTL			0x04
+#define HSFSTS_CTL_FSMIE		BIT(31)
+#define HSFSTS_CTL_FDBC_SHIFT		24
+#define HSFSTS_CTL_FDBC_MASK		(0x3f << HSFSTS_CTL_FDBC_SHIFT)
+
+#define HSFSTS_CTL_FCYCLE_SHIFT		17
+#define HSFSTS_CTL_FCYCLE_MASK		(0x0f << HSFSTS_CTL_FCYCLE_SHIFT)
+/* HW sequencer opcodes */
+#define HSFSTS_CTL_FCYCLE_READ		(0x00 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_WRITE		(0x02 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_ERASE		(0x03 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_ERASE_64K	(0x04 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_RDID		(0x06 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_WRSR		(0x07 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_RDSR		(0x08 << HSFSTS_CTL_FCYCLE_SHIFT)
+
+#define HSFSTS_CTL_FGO			BIT(16)
+#define HSFSTS_CTL_FLOCKDN		BIT(15)
+#define HSFSTS_CTL_FDV			BIT(14)
+#define HSFSTS_CTL_SCIP			BIT(5)
+#define HSFSTS_CTL_AEL			BIT(2)
+#define HSFSTS_CTL_FCERR		BIT(1)
+#define HSFSTS_CTL_FDONE		BIT(0)
+
+#define FADDR				0x08
+#define DLOCK				0x0c
+#define FDATA(n)			(0x10 + ((n) * 4))
+
+#define FRACC				0x50
+
+#define FREG(n)				(0x54 + ((n) * 4))
+#define FREG_BASE_MASK			0x3fff
+#define FREG_LIMIT_SHIFT		16
+#define FREG_LIMIT_MASK			(0x03fff << FREG_LIMIT_SHIFT)
+
+/* Offset is from @ispi->pregs */
+#define PR(n)				((n) * 4)
+#define PR_WPE				BIT(31)
+#define PR_LIMIT_SHIFT			16
+#define PR_LIMIT_MASK			(0x3fff << PR_LIMIT_SHIFT)
+#define PR_RPE				BIT(15)
+#define PR_BASE_MASK			0x3fff
+/* Last PR is GPR0 */
+#define PR_NUM				(5 + 1)
+
+/* Offsets are from @ispi->sregs */
+#define SSFSTS_CTL			0x00
+#define SSFSTS_CTL_FSMIE		BIT(23)
+#define SSFSTS_CTL_DS			BIT(22)
+#define SSFSTS_CTL_DBC_SHIFT		16
+#define SSFSTS_CTL_SPOP			BIT(11)
+#define SSFSTS_CTL_ACS			BIT(10)
+#define SSFSTS_CTL_SCGO			BIT(9)
+#define SSFSTS_CTL_COP_SHIFT		12
+#define SSFSTS_CTL_FRS			BIT(7)
+#define SSFSTS_CTL_DOFRS		BIT(6)
+#define SSFSTS_CTL_AEL			BIT(4)
+#define SSFSTS_CTL_FCERR		BIT(3)
+#define SSFSTS_CTL_FDONE		BIT(2)
+#define SSFSTS_CTL_SCIP			BIT(0)
+
+#define PREOP_OPTYPE			0x04
+#define OPMENU0				0x08
+#define OPMENU1				0x0c
+
+/* CPU specifics */
+#define BYT_PR				0x74
+#define BYT_SSFSTS_CTL			0x90
+#define BYT_BCR				0xfc
+#define BYT_BCR_WPD			BIT(0)
+#define BYT_FREG_NUM			5
+
+#define LPT_PR				0x74
+#define LPT_SSFSTS_CTL			0x90
+#define LPT_FREG_NUM			5
+
+#define BXT_PR				0x84
+#define BXT_SSFSTS_CTL			0xa0
+#define BXT_FREG_NUM			12
+
+#define INTEL_SPI_TIMEOUT		5000 /* ms */
+#define INTEL_SPI_FIFO_SZ		64
+
+/**
+ * struct intel_spi - Driver private data
+ * @dev: Device pointer
+ * @info: Pointer to board specific info
+ * @nor: SPI NOR layer structure
+ * @base: Beginning of MMIO space
+ * @pregs: Start of protection registers
+ * @sregs: Start of software sequencer registers
+ * @nregions: Maximum number of regions
+ * @writeable: Is the chip writeable
+ * @swseq: Use SW sequencer in register reads/writes
+ * @erase_64k: 64k erase supported
+ * @opcodes: Opcodes which are supported. This are programmed by BIOS
+ *           before it locks down the controller.
+ * @preopcodes: Preopcodes which are supported.
+ */
+struct intel_spi {
+	struct device *dev;
+	const struct intel_spi_boardinfo *info;
+	struct spi_nor nor;
+	void __iomem *base;
+	void __iomem *pregs;
+	void __iomem *sregs;
+	size_t nregions;
+	bool writeable;
+	bool swseq;
+	bool erase_64k;
+	u8 opcodes[8];
+	u8 preopcodes[2];
+};
+
+static bool writeable;
+module_param(writeable, bool, 0);
+MODULE_PARM_DESC(writeable, "Enable write access to SPI flash chip (default=0)");
+
+static void intel_spi_dump_regs(struct intel_spi *ispi)
+{
+	u32 value;
+	int i;
+
+	dev_dbg(ispi->dev, "BFPREG=0x%08x\n", readl(ispi->base + BFPREG));
+
+	value = readl(ispi->base + HSFSTS_CTL);
+	dev_dbg(ispi->dev, "HSFSTS_CTL=0x%08x\n", value);
+	if (value & HSFSTS_CTL_FLOCKDN)
+		dev_dbg(ispi->dev, "-> Locked\n");
+
+	dev_dbg(ispi->dev, "FADDR=0x%08x\n", readl(ispi->base + FADDR));
+	dev_dbg(ispi->dev, "DLOCK=0x%08x\n", readl(ispi->base + DLOCK));
+
+	for (i = 0; i < 16; i++)
+		dev_dbg(ispi->dev, "FDATA(%d)=0x%08x\n",
+			i, readl(ispi->base + FDATA(i)));
+
+	dev_dbg(ispi->dev, "FRACC=0x%08x\n", readl(ispi->base + FRACC));
+
+	for (i = 0; i < ispi->nregions; i++)
+		dev_dbg(ispi->dev, "FREG(%d)=0x%08x\n", i,
+			readl(ispi->base + FREG(i)));
+	for (i = 0; i < PR_NUM; i++)
+		dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
+			readl(ispi->pregs + PR(i)));
+
+	value = readl(ispi->sregs + SSFSTS_CTL);
+	dev_dbg(ispi->dev, "SSFSTS_CTL=0x%08x\n", value);
+	dev_dbg(ispi->dev, "PREOP_OPTYPE=0x%08x\n",
+		readl(ispi->sregs + PREOP_OPTYPE));
+	dev_dbg(ispi->dev, "OPMENU0=0x%08x\n", readl(ispi->sregs + OPMENU0));
+	dev_dbg(ispi->dev, "OPMENU1=0x%08x\n", readl(ispi->sregs + OPMENU1));
+
+	if (ispi->info->type == INTEL_SPI_BYT)
+		dev_dbg(ispi->dev, "BCR=0x%08x\n", readl(ispi->base + BYT_BCR));
+
+	dev_dbg(ispi->dev, "Protected regions:\n");
+	for (i = 0; i < PR_NUM; i++) {
+		u32 base, limit;
+
+		value = readl(ispi->pregs + PR(i));
+		if (!(value & (PR_WPE | PR_RPE)))
+			continue;
+
+		limit = (value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
+		base = value & PR_BASE_MASK;
+
+		dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x [%c%c]\n",
+			 i, base << 12, (limit << 12) | 0xfff,
+			 value & PR_WPE ? 'W' : '.',
+			 value & PR_RPE ? 'R' : '.');
+	}
+
+	dev_dbg(ispi->dev, "Flash regions:\n");
+	for (i = 0; i < ispi->nregions; i++) {
+		u32 region, base, limit;
+
+		region = readl(ispi->base + FREG(i));
+		base = region & FREG_BASE_MASK;
+		limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
+
+		if (base >= limit || (i > 0 && limit == 0))
+			dev_dbg(ispi->dev, " %02d disabled\n", i);
+		else
+			dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x\n",
+				 i, base << 12, (limit << 12) | 0xfff);
+	}
+
+	dev_dbg(ispi->dev, "Using %cW sequencer for register access\n",
+		ispi->swseq ? 'S' : 'H');
+}
+
+/* Reads max INTEL_SPI_FIFO_SZ bytes from the device fifo */
+static int intel_spi_read_block(struct intel_spi *ispi, void *buf, size_t size)
+{
+	size_t bytes;
+	int i = 0;
+
+	if (size > INTEL_SPI_FIFO_SZ)
+		return -EINVAL;
+
+	while (size > 0) {
+		bytes = min_t(size_t, size, 4);
+		memcpy_fromio(buf, ispi->base + FDATA(i), bytes);
+		size -= bytes;
+		buf += bytes;
+		i++;
+	}
+
+	return 0;
+}
+
+/* Writes max INTEL_SPI_FIFO_SZ bytes to the device fifo */
+static int intel_spi_write_block(struct intel_spi *ispi, const void *buf,
+				 size_t size)
+{
+	size_t bytes;
+	int i = 0;
+
+	if (size > INTEL_SPI_FIFO_SZ)
+		return -EINVAL;
+
+	while (size > 0) {
+		bytes = min_t(size_t, size, 4);
+		memcpy_toio(ispi->base + FDATA(i), buf, bytes);
+		size -= bytes;
+		buf += bytes;
+		i++;
+	}
+
+	return 0;
+}
+
+static int intel_spi_wait_hw_busy(struct intel_spi *ispi)
+{
+	u32 val;
+
+	return readl_poll_timeout(ispi->base + HSFSTS_CTL, val,
+				  !(val & HSFSTS_CTL_SCIP), 0,
+				  INTEL_SPI_TIMEOUT * 1000);
+}
+
+static int intel_spi_wait_sw_busy(struct intel_spi *ispi)
+{
+	u32 val;
+
+	return readl_poll_timeout(ispi->sregs + SSFSTS_CTL, val,
+				  !(val & SSFSTS_CTL_SCIP), 0,
+				  INTEL_SPI_TIMEOUT * 1000);
+}
+
+static int intel_spi_init(struct intel_spi *ispi)
+{
+	u32 opmenu0, opmenu1, val;
+	int i;
+
+	switch (ispi->info->type) {
+	case INTEL_SPI_BYT:
+		ispi->sregs = ispi->base + BYT_SSFSTS_CTL;
+		ispi->pregs = ispi->base + BYT_PR;
+		ispi->nregions = BYT_FREG_NUM;
+
+		if (writeable) {
+			/* Disable write protection */
+			val = readl(ispi->base + BYT_BCR);
+			if (!(val & BYT_BCR_WPD)) {
+				val |= BYT_BCR_WPD;
+				writel(val, ispi->base + BYT_BCR);
+				val = readl(ispi->base + BYT_BCR);
+			}
+
+			ispi->writeable = !!(val & BYT_BCR_WPD);
+		}
+
+		break;
+
+	case INTEL_SPI_LPT:
+		ispi->sregs = ispi->base + LPT_SSFSTS_CTL;
+		ispi->pregs = ispi->base + LPT_PR;
+		ispi->nregions = LPT_FREG_NUM;
+		break;
+
+	case INTEL_SPI_BXT:
+		ispi->sregs = ispi->base + BXT_SSFSTS_CTL;
+		ispi->pregs = ispi->base + BXT_PR;
+		ispi->nregions = BXT_FREG_NUM;
+		ispi->erase_64k = true;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	/* Disable #SMI generation */
+	val = readl(ispi->base + HSFSTS_CTL);
+	val &= ~HSFSTS_CTL_FSMIE;
+	writel(val, ispi->base + HSFSTS_CTL);
+
+	/*
+	 * BIOS programs allowed opcodes and then locks down the register.
+	 * So read back what opcodes it decided to support. That's the set
+	 * we are going to support as well.
+	 */
+	opmenu0 = readl(ispi->sregs + OPMENU0);
+	opmenu1 = readl(ispi->sregs + OPMENU1);
+
+	/*
+	 * Some controllers can only do basic operations using hardware
+	 * sequencer. All other operations are supposed to be carried out
+	 * using software sequencer. If we find that BIOS has programmed
+	 * opcodes for the software sequencer we use that over the hardware
+	 * sequencer.
+	 */
+	if (opmenu0 && opmenu1) {
+		for (i = 0; i < ARRAY_SIZE(ispi->opcodes) / 2; i++) {
+			ispi->opcodes[i] = opmenu0 >> i * 8;
+			ispi->opcodes[i + 4] = opmenu1 >> i * 8;
+		}
+
+		val = readl(ispi->sregs + PREOP_OPTYPE);
+		ispi->preopcodes[0] = val;
+		ispi->preopcodes[1] = val >> 8;
+
+		/* Disable #SMI generation from SW sequencer */
+		val = readl(ispi->sregs + SSFSTS_CTL);
+		val &= ~SSFSTS_CTL_FSMIE;
+		writel(val, ispi->sregs + SSFSTS_CTL);
+
+		ispi->swseq = true;
+	}
+
+	intel_spi_dump_regs(ispi);
+
+	return 0;
+}
+
+static int intel_spi_opcode_index(struct intel_spi *ispi, u8 opcode)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++)
+		if (ispi->opcodes[i] == opcode)
+			return i;
+	return -EINVAL;
+}
+
+static int intel_spi_hw_cycle(struct intel_spi *ispi, u8 opcode, u8 *buf,
+			      int len)
+{
+	u32 val, status;
+	int ret;
+
+	val = readl(ispi->base + HSFSTS_CTL);
+	val &= ~(HSFSTS_CTL_FCYCLE_MASK | HSFSTS_CTL_FDBC_MASK);
+
+	switch (opcode) {
+	case SPINOR_OP_RDID:
+		val |= HSFSTS_CTL_FCYCLE_RDID;
+		break;
+	case SPINOR_OP_WRSR:
+		val |= HSFSTS_CTL_FCYCLE_WRSR;
+		break;
+	case SPINOR_OP_RDSR:
+		val |= HSFSTS_CTL_FCYCLE_RDSR;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	val |= (len - 1) << HSFSTS_CTL_FDBC_SHIFT;
+	val |= HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+	val |= HSFSTS_CTL_FGO;
+	writel(val, ispi->base + HSFSTS_CTL);
+
+	ret = intel_spi_wait_hw_busy(ispi);
+	if (ret)
+		return ret;
+
+	status = readl(ispi->base + HSFSTS_CTL);
+	if (status & HSFSTS_CTL_FCERR)
+		return -EIO;
+	else if (status & HSFSTS_CTL_AEL)
+		return -EACCES;
+
+	return 0;
+}
+
+static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, u8 *buf,
+			      int len)
+{
+	u32 val, status;
+	int ret;
+
+	ret = intel_spi_opcode_index(ispi, opcode);
+	if (ret < 0)
+		return ret;
+
+	val = (len << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
+	val |= ret << SSFSTS_CTL_COP_SHIFT;
+	val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
+	val |= SSFSTS_CTL_SCGO;
+	writel(val, ispi->sregs + SSFSTS_CTL);
+
+	ret = intel_spi_wait_sw_busy(ispi);
+	if (ret)
+		return ret;
+
+	status = readl(ispi->base + SSFSTS_CTL);
+	if (status & SSFSTS_CTL_FCERR)
+		return -EIO;
+	else if (status & SSFSTS_CTL_AEL)
+		return -EACCES;
+
+	return 0;
+}
+
+static int intel_spi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	struct intel_spi *ispi = nor->priv;
+	int ret;
+
+	/* Address of the first chip */
+	writel(0, ispi->base + FADDR);
+
+	if (ispi->swseq)
+		ret = intel_spi_sw_cycle(ispi, opcode, buf, len);
+	else
+		ret = intel_spi_hw_cycle(ispi, opcode, buf, len);
+
+	if (ret)
+		return ret;
+
+	return intel_spi_read_block(ispi, buf, len);
+}
+
+static int intel_spi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	struct intel_spi *ispi = nor->priv;
+	int ret;
+
+	/*
+	 * This is handled with atomic operation and preop code in Intel
+	 * controller so skip it here now.
+	 */
+	if (opcode == SPINOR_OP_WREN)
+		return 0;
+
+	writel(0, ispi->base + FADDR);
+
+	/* Write the value beforehand */
+	ret = intel_spi_write_block(ispi, buf, len);
+	if (ret)
+		return ret;
+
+	if (ispi->swseq)
+		return intel_spi_sw_cycle(ispi, opcode, buf, len);
+	return intel_spi_hw_cycle(ispi, opcode, buf, len);
+}
+
+static ssize_t intel_spi_read(struct spi_nor *nor, loff_t from, size_t len,
+			      u_char *read_buf)
+{
+	struct intel_spi *ispi = nor->priv;
+	size_t block_size, retlen = 0;
+	u32 val, status;
+	ssize_t ret;
+
+	switch (nor->read_opcode) {
+	case SPINOR_OP_READ:
+	case SPINOR_OP_READ_FAST:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	while (len > 0) {
+		block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
+
+		writel(from, ispi->base + FADDR);
+
+		val = readl(ispi->base + HSFSTS_CTL);
+		val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
+		val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+		val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
+		val |= HSFSTS_CTL_FCYCLE_READ;
+		val |= HSFSTS_CTL_FGO;
+		writel(val, ispi->base + HSFSTS_CTL);
+
+		ret = intel_spi_wait_hw_busy(ispi);
+		if (ret)
+			return ret;
+
+		status = readl(ispi->base + HSFSTS_CTL);
+		if (status & HSFSTS_CTL_FCERR)
+			ret = -EIO;
+		else if (status & HSFSTS_CTL_AEL)
+			ret = -EACCES;
+
+		if (ret < 0) {
+			dev_err(ispi->dev, "read error: %llx: %#x\n", from,
+				status);
+			return ret;
+		}
+
+		ret = intel_spi_read_block(ispi, read_buf, block_size);
+		if (ret)
+			return ret;
+
+		len -= block_size;
+		from += block_size;
+		retlen += block_size;
+		read_buf += block_size;
+	}
+
+	return retlen;
+}
+
+static ssize_t intel_spi_write(struct spi_nor *nor, loff_t to, size_t len,
+			       const u_char *write_buf)
+{
+	struct intel_spi *ispi = nor->priv;
+	size_t block_size, retlen = 0;
+	u32 val, status;
+	ssize_t ret;
+
+	while (len > 0) {
+		block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
+
+		writel(to, ispi->base + FADDR);
+
+		val = readl(ispi->base + HSFSTS_CTL);
+		val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
+		val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+		val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
+		val |= HSFSTS_CTL_FCYCLE_WRITE;
+
+		/* Write enable */
+		if (ispi->preopcodes[1] == SPINOR_OP_WREN)
+			val |= SSFSTS_CTL_SPOP;
+		val |= SSFSTS_CTL_ACS;
+		writel(val, ispi->base + HSFSTS_CTL);
+
+		ret = intel_spi_write_block(ispi, write_buf, block_size);
+		if (ret) {
+			dev_err(ispi->dev, "failed to write block\n");
+			return ret;
+		}
+
+		/* Start the write now */
+		val = readl(ispi->base + HSFSTS_CTL);
+		writel(val | HSFSTS_CTL_FGO, ispi->base + HSFSTS_CTL);
+
+		ret = intel_spi_wait_hw_busy(ispi);
+		if (ret) {
+			dev_err(ispi->dev, "timeout\n");
+			return ret;
+		}
+
+		status = readl(ispi->base + HSFSTS_CTL);
+		if (status & HSFSTS_CTL_FCERR)
+			ret = -EIO;
+		else if (status & HSFSTS_CTL_AEL)
+			ret = -EACCES;
+
+		if (ret < 0) {
+			dev_err(ispi->dev, "write error: %llx: %#x\n", to,
+				status);
+			return ret;
+		}
+
+		len -= block_size;
+		to += block_size;
+		retlen += block_size;
+		write_buf += block_size;
+	}
+
+	return retlen;
+}
+
+static int intel_spi_erase(struct spi_nor *nor, loff_t offs)
+{
+	size_t erase_size, len = nor->mtd.erasesize;
+	struct intel_spi *ispi = nor->priv;
+	u32 val, status, cmd;
+	int ret;
+
+	/* If the hardware can do 64k erase use that when possible */
+	if (len >= SZ_64K && ispi->erase_64k) {
+		cmd = HSFSTS_CTL_FCYCLE_ERASE_64K;
+		erase_size = SZ_64K;
+	} else {
+		cmd = HSFSTS_CTL_FCYCLE_ERASE;
+		erase_size = SZ_4K;
+	}
+
+	while (len > 0) {
+		writel(offs, ispi->base + FADDR);
+
+		val = readl(ispi->base + HSFSTS_CTL);
+		val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
+		val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+		val |= cmd;
+		val |= HSFSTS_CTL_FGO;
+		writel(val, ispi->base + HSFSTS_CTL);
+
+		ret = intel_spi_wait_hw_busy(ispi);
+		if (ret)
+			return ret;
+
+		status = readl(ispi->base + HSFSTS_CTL);
+		if (status & HSFSTS_CTL_FCERR)
+			return -EIO;
+		else if (status & HSFSTS_CTL_AEL)
+			return -EACCES;
+
+		offs += erase_size;
+		len -= erase_size;
+	}
+
+	return 0;
+}
+
+static bool intel_spi_is_protected(const struct intel_spi *ispi,
+				   unsigned int base, unsigned int limit)
+{
+	int i;
+
+	for (i = 0; i < PR_NUM; i++) {
+		u32 pr_base, pr_limit, pr_value;
+
+		pr_value = readl(ispi->pregs + PR(i));
+		if (!(pr_value & (PR_WPE | PR_RPE)))
+			continue;
+
+		pr_limit = (pr_value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
+		pr_base = pr_value & PR_BASE_MASK;
+
+		if (pr_base >= base && pr_limit <= limit)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * There will be a single partition holding all enabled flash regions. We
+ * call this "BIOS".
+ */
+static void intel_spi_fill_partition(struct intel_spi *ispi,
+				     struct mtd_partition *part)
+{
+	u64 end;
+	int i;
+
+	memset(part, 0, sizeof(*part));
+
+	/* Start from the mandatory descriptor region */
+	part->size = 4096;
+	part->name = "BIOS";
+
+	/*
+	 * Now try to find where this partition ends based on the flash
+	 * region registers.
+	 */
+	for (i = 1; i < ispi->nregions; i++) {
+		u32 region, base, limit;
+
+		region = readl(ispi->base + FREG(i));
+		base = region & FREG_BASE_MASK;
+		limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
+
+		if (base >= limit || limit == 0)
+			continue;
+
+		/*
+		 * If any of the regions have protection bits set, make the
+		 * whole partition read-only to be on the safe side.
+		 */
+		if (intel_spi_is_protected(ispi, base, limit))
+			ispi->writeable = 0;
+
+		end = (limit << 12) + 4096;
+		if (end > part->size)
+			part->size = end;
+	}
+}
+
+struct intel_spi *intel_spi_probe(struct device *dev,
+	struct resource *mem, const struct intel_spi_boardinfo *info)
+{
+	struct mtd_partition part;
+	struct intel_spi *ispi;
+	int ret;
+
+	if (!info || !mem)
+		return ERR_PTR(-EINVAL);
+
+	ispi = devm_kzalloc(dev, sizeof(*ispi), GFP_KERNEL);
+	if (!ispi)
+		return ERR_PTR(-ENOMEM);
+
+	ispi->base = devm_ioremap_resource(dev, mem);
+	if (IS_ERR(ispi->base))
+		return ispi->base;
+
+	ispi->dev = dev;
+	ispi->info = info;
+	ispi->writeable = info->writeable;
+
+	ret = intel_spi_init(ispi);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ispi->nor.dev = ispi->dev;
+	ispi->nor.priv = ispi;
+	ispi->nor.read_reg = intel_spi_read_reg;
+	ispi->nor.write_reg = intel_spi_write_reg;
+	ispi->nor.read = intel_spi_read;
+	ispi->nor.write = intel_spi_write;
+	ispi->nor.erase = intel_spi_erase;
+
+	ret = spi_nor_scan(&ispi->nor, NULL, SPI_NOR_NORMAL);
+	if (ret) {
+		dev_info(dev, "failed to locate the chip\n");
+		return ERR_PTR(ret);
+	}
+
+	intel_spi_fill_partition(ispi, &part);
+
+	/* Prevent writes if not explicitly enabled */
+	if (!ispi->writeable || !writeable)
+		ispi->nor.mtd.flags &= ~MTD_WRITEABLE;
+
+	ret = mtd_device_parse_register(&ispi->nor.mtd, NULL, NULL, &part, 1);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return ispi;
+}
+EXPORT_SYMBOL_GPL(intel_spi_probe);
+
+int intel_spi_remove(struct intel_spi *ispi)
+{
+	return mtd_device_unregister(&ispi->nor.mtd);
+}
+EXPORT_SYMBOL_GPL(intel_spi_remove);
+
+MODULE_DESCRIPTION("Intel PCH/PCU SPI flash core driver");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_LICENSE("GPL v2");

drivers/mtd/spi-nor/intel-spi.h

+/*
+ * Intel PCH/PCU SPI flash driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef INTEL_SPI_H
+#define INTEL_SPI_H
+
+#include <linux/platform_data/intel-spi.h>
+
+struct intel_spi;
+struct resource;
+
+struct intel_spi *intel_spi_probe(struct device *dev,
+	struct resource *mem, const struct intel_spi_boardinfo *info);
+int intel_spi_remove(struct intel_spi *ispi);
+
+#endif /* INTEL_SPI_H */

include/linux/mfd/lpc_ich.h

@@ -20,6 +20,8 @@
 #ifndef LPC_ICH_H
 #define LPC_ICH_H
 
+#include <linux/platform_data/intel-spi.h>
+
 /* GPIO resources */
 #define ICH_RES_GPIO	0
 #define ICH_RES_GPE0	1
@@ -40,6 +42,7 @@ struct lpc_ich_info {
 	char name[32];
 	unsigned int iTCO_version;
 	unsigned int gpio_version;
+	enum intel_spi_type spi_type;
 	u8 use_gpio;
 };
 

include/linux/platform_data/intel-spi.h

+/*
+ * Intel PCH/PCU SPI flash driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef INTEL_SPI_PDATA_H
+#define INTEL_SPI_PDATA_H
+
+enum intel_spi_type {
+	INTEL_SPI_BYT = 1,
+	INTEL_SPI_LPT,
+	INTEL_SPI_BXT,
+};
+
+/**
+ * struct intel_spi_boardinfo - Board specific data for Intel SPI driver
+ * @type: Type which this controller is compatible with
+ * @writeable: The chip is writeable
+ */
+struct intel_spi_boardinfo {
+	enum intel_spi_type type;
+	bool writeable;
+};
+
+#endif /* INTEL_SPI_PDATA_H */