mtd: spi-nor: Prepare core / manufacturer code split

Move all SPI NOR controller drivers to a controllers/ sub-directory
so that we only have SPI NOR related source files under
drivers/mtd/spi-nor/.

Rename spi-nor.c into core.c, we are about to split this file in multiple
source files (one per manufacturer, plus one for the SFDP parsing logic).

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>

1 files changed, 960 insertions, 0 deletions

diff --git a/drivers/mtd/spi-nor/controllers/intel-spi.c b/drivers/mtd/spi-nor/controllers/intel-spi.c
new file mode 100644
index 000000000000..61d2a0ad2131
--- /dev/null
+++ b/drivers/mtd/spi-nor/controllers/intel-spi.c
@@ -0,0 +1,960 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel PCH/PCU SPI flash driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#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
+
+/* 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
+
+#define OPTYPE_READ_NO_ADDR		0
+#define OPTYPE_WRITE_NO_ADDR		1
+#define OPTYPE_READ_WITH_ADDR		2
+#define OPTYPE_WRITE_WITH_ADDR		3
+
+/* 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 BYT_PR_NUM			5
+
+#define LPT_PR				0x74
+#define LPT_SSFSTS_CTL			0x90
+#define LPT_FREG_NUM			5
+#define LPT_PR_NUM			5
+
+#define BXT_PR				0x84
+#define BXT_SSFSTS_CTL			0xa0
+#define BXT_FREG_NUM			12
+#define BXT_PR_NUM			6
+
+#define CNL_PR				0x84
+#define CNL_FREG_NUM			6
+#define CNL_PR_NUM			5
+
+#define LVSCC				0xc4
+#define UVSCC				0xc8
+#define ERASE_OPCODE_SHIFT		8
+#define ERASE_OPCODE_MASK		(0xff << ERASE_OPCODE_SHIFT)
+#define ERASE_64K_OPCODE_SHIFT		16
+#define ERASE_64K_OPCODE_MASK		(0xff << ERASE_OPCODE_SHIFT)
+
+#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
+ * @pr_num: Maximum number of protected range registers
+ * @writeable: Is the chip writeable
+ * @locked: Is SPI setting locked
+ * @swseq_reg: Use SW sequencer in register reads/writes
+ * @swseq_erase: Use SW sequencer in erase operation
+ * @erase_64k: 64k erase supported
+ * @atomic_preopcode: Holds preopcode when atomic sequence is requested
+ * @opcodes: Opcodes which are supported. This are programmed by BIOS
+ *           before it locks down the controller.
+ */
+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;
+	size_t pr_num;
+	bool writeable;
+	bool locked;
+	bool swseq_reg;
+	bool swseq_erase;
+	bool erase_64k;
+	u8 atomic_preopcode;
+	u8 opcodes[8];
+};
+
+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 < ispi->pr_num; i++)
+		dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
+			readl(ispi->pregs + PR(i)));
+
+	if (ispi->sregs) {
+		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, "LVSCC=0x%08x\n", readl(ispi->base + LVSCC));
+	dev_dbg(ispi->dev, "UVSCC=0x%08x\n", readl(ispi->base + UVSCC));
+
+	dev_dbg(ispi->dev, "Protected regions:\n");
+	for (i = 0; i < ispi->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_reg ? 'S' : 'H');
+	dev_dbg(ispi->dev, "Using %cW sequencer for erase operation\n",
+		ispi->swseq_erase ? '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), 40,
+				  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), 40,
+				  INTEL_SPI_TIMEOUT * 1000);
+}
+
+static int intel_spi_init(struct intel_spi *ispi)
+{
+	u32 opmenu0, opmenu1, lvscc, uvscc, 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;
+		ispi->pr_num = BYT_PR_NUM;
+		ispi->swseq_reg = true;
+
+		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;
+		ispi->pr_num = LPT_PR_NUM;
+		ispi->swseq_reg = true;
+		break;
+
+	case INTEL_SPI_BXT:
+		ispi->sregs = ispi->base + BXT_SSFSTS_CTL;
+		ispi->pregs = ispi->base + BXT_PR;
+		ispi->nregions = BXT_FREG_NUM;
+		ispi->pr_num = BXT_PR_NUM;
+		ispi->erase_64k = true;
+		break;
+
+	case INTEL_SPI_CNL:
+		ispi->sregs = NULL;
+		ispi->pregs = ispi->base + CNL_PR;
+		ispi->nregions = CNL_FREG_NUM;
+		ispi->pr_num = CNL_PR_NUM;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	/* Disable #SMI generation from HW sequencer */
+	val = readl(ispi->base + HSFSTS_CTL);
+	val &= ~HSFSTS_CTL_FSMIE;
+	writel(val, ispi->base + HSFSTS_CTL);
+
+	/*
+	 * Determine whether erase operation should use HW or SW sequencer.
+	 *
+	 * The HW sequencer has a predefined list of opcodes, with only the
+	 * erase opcode being programmable in LVSCC and UVSCC registers.
+	 * If these registers don't contain a valid erase opcode, erase
+	 * cannot be done using HW sequencer.
+	 */
+	lvscc = readl(ispi->base + LVSCC);
+	uvscc = readl(ispi->base + UVSCC);
+	if (!(lvscc & ERASE_OPCODE_MASK) || !(uvscc & ERASE_OPCODE_MASK))
+		ispi->swseq_erase = true;
+	/* SPI controller on Intel BXT supports 64K erase opcode */
+	if (ispi->info->type == INTEL_SPI_BXT && !ispi->swseq_erase)
+		if (!(lvscc & ERASE_64K_OPCODE_MASK) ||
+		    !(uvscc & ERASE_64K_OPCODE_MASK))
+			ispi->erase_64k = false;
+
+	if (ispi->sregs == NULL && (ispi->swseq_reg || ispi->swseq_erase)) {
+		dev_err(ispi->dev, "software sequencer not supported, but required\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Some controllers can only do basic operations using hardware
+	 * sequencer. All other operations are supposed to be carried out
+	 * using software sequencer.
+	 */
+	if (ispi->swseq_reg) {
+		/* Disable #SMI generation from SW sequencer */
+		val = readl(ispi->sregs + SSFSTS_CTL);
+		val &= ~SSFSTS_CTL_FSMIE;
+		writel(val, ispi->sregs + SSFSTS_CTL);
+	}
+
+	/* Check controller's lock status */
+	val = readl(ispi->base + HSFSTS_CTL);
+	ispi->locked = !!(val & HSFSTS_CTL_FLOCKDN);
+
+	if (ispi->locked && ispi->sregs) {
+		/*
+		 * 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);
+
+		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;
+			}
+		}
+	}
+
+	intel_spi_dump_regs(ispi);
+
+	return 0;
+}
+
+static int intel_spi_opcode_index(struct intel_spi *ispi, u8 opcode, int optype)
+{
+	int i;
+	int preop;
+
+	if (ispi->locked) {
+		for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++)
+			if (ispi->opcodes[i] == opcode)
+				return i;
+
+		return -EINVAL;
+	}
+
+	/* The lock is off, so just use index 0 */
+	writel(opcode, ispi->sregs + OPMENU0);
+	preop = readw(ispi->sregs + PREOP_OPTYPE);
+	writel(optype << 16 | preop, ispi->sregs + PREOP_OPTYPE);
+
+	return 0;
+}
+
+static int intel_spi_hw_cycle(struct intel_spi *ispi, u8 opcode, size_t 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;
+	}
+
+	if (len > INTEL_SPI_FIFO_SZ)
+		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, size_t len,
+			      int optype)
+{
+	u32 val = 0, status;
+	u8 atomic_preopcode;
+	int ret;
+
+	ret = intel_spi_opcode_index(ispi, opcode, optype);
+	if (ret < 0)
+		return ret;
+
+	if (len > INTEL_SPI_FIFO_SZ)
+		return -EINVAL;
+
+	/*
+	 * Always clear it after each SW sequencer operation regardless
+	 * of whether it is successful or not.
+	 */
+	atomic_preopcode = ispi->atomic_preopcode;
+	ispi->atomic_preopcode = 0;
+
+	/* Only mark 'Data Cycle' bit when there is data to be transferred */
+	if (len > 0)
+		val = ((len - 1) << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
+	val |= ret << SSFSTS_CTL_COP_SHIFT;
+	val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
+	val |= SSFSTS_CTL_SCGO;
+	if (atomic_preopcode) {
+		u16 preop;
+
+		switch (optype) {
+		case OPTYPE_WRITE_NO_ADDR:
+		case OPTYPE_WRITE_WITH_ADDR:
+			/* Pick matching preopcode for the atomic sequence */
+			preop = readw(ispi->sregs + PREOP_OPTYPE);
+			if ((preop & 0xff) == atomic_preopcode)
+				; /* Do nothing */
+			else if ((preop >> 8) == atomic_preopcode)
+				val |= SSFSTS_CTL_SPOP;
+			else
+				return -EINVAL;
+
+			/* Enable atomic sequence */
+			val |= SSFSTS_CTL_ACS;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+
+	}
+	writel(val, ispi->sregs + SSFSTS_CTL);
+
+	ret = intel_spi_wait_sw_busy(ispi);
+	if (ret)
+		return ret;
+
+	status = readl(ispi->sregs + 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,
+			      size_t len)
+{
+	struct intel_spi *ispi = nor->priv;
+	int ret;
+
+	/* Address of the first chip */
+	writel(0, ispi->base + FADDR);
+
+	if (ispi->swseq_reg)
+		ret = intel_spi_sw_cycle(ispi, opcode, len,
+					 OPTYPE_READ_NO_ADDR);
+	else
+		ret = intel_spi_hw_cycle(ispi, opcode, 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, const u8 *buf,
+			       size_t len)
+{
+	struct intel_spi *ispi = nor->priv;
+	int ret;
+
+	/*
+	 * This is handled with atomic operation and preop code in Intel
+	 * controller so we only verify that it is available. If the
+	 * controller is not locked, program the opcode to the PREOP
+	 * register for later use.
+	 *
+	 * When hardware sequencer is used there is no need to program
+	 * any opcodes (it handles them automatically as part of a command).
+	 */
+	if (opcode == SPINOR_OP_WREN) {
+		u16 preop;
+
+		if (!ispi->swseq_reg)
+			return 0;
+
+		preop = readw(ispi->sregs + PREOP_OPTYPE);
+		if ((preop & 0xff) != opcode && (preop >> 8) != opcode) {
+			if (ispi->locked)
+				return -EINVAL;
+			writel(opcode, ispi->sregs + PREOP_OPTYPE);
+		}
+
+		/*
+		 * This enables atomic sequence on next SW sycle. Will
+		 * be cleared after next operation.
+		 */
+		ispi->atomic_preopcode = opcode;
+		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_reg)
+		return intel_spi_sw_cycle(ispi, opcode, len,
+					  OPTYPE_WRITE_NO_ADDR);
+	return intel_spi_hw_cycle(ispi, opcode, 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;
+
+	/*
+	 * Atomic sequence is not expected with HW sequencer reads. Make
+	 * sure it is cleared regardless.
+	 */
+	if (WARN_ON_ONCE(ispi->atomic_preopcode))
+		ispi->atomic_preopcode = 0;
+
+	switch (nor->read_opcode) {
+	case SPINOR_OP_READ:
+	case SPINOR_OP_READ_FAST:
+	case SPINOR_OP_READ_4B:
+	case SPINOR_OP_READ_FAST_4B:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	while (len > 0) {
+		block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
+
+		/* Read cannot cross 4K boundary */
+		block_size = min_t(loff_t, from + block_size,
+				   round_up(from + 1, SZ_4K)) - from;
+
+		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;
+
+	/* Not needed with HW sequencer write, make sure it is cleared */
+	ispi->atomic_preopcode = 0;
+
+	while (len > 0) {
+		block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
+
+		/* Write cannot cross 4K boundary */
+		block_size = min_t(loff_t, to + block_size,
+				   round_up(to + 1, SZ_4K)) - to;
+
+		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;
+
+		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 |= HSFSTS_CTL_FGO;
+		writel(val, 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;
+	}
+
+	if (ispi->swseq_erase) {
+		while (len > 0) {
+			writel(offs, ispi->base + FADDR);
+
+			ret = intel_spi_sw_cycle(ispi, nor->erase_opcode,
+						 0, OPTYPE_WRITE_WITH_ADDR);
+			if (ret)
+				return ret;
+
+			offs += erase_size;
+			len -= erase_size;
+		}
+
+		return 0;
+	}
+
+	/* Not needed with HW sequencer erase, make sure it is cleared */
+	ispi->atomic_preopcode = 0;
+
+	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 < ispi->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 = false;
+
+		end = (limit << 12) + 4096;
+		if (end > part->size)
+			part->size = end;
+	}
+}
+
+static const struct spi_nor_controller_ops intel_spi_controller_ops = {
+	.read_reg = intel_spi_read_reg,
+	.write_reg = intel_spi_write_reg,
+	.read = intel_spi_read,
+	.write = intel_spi_write,
+	.erase = intel_spi_erase,
+};
+
+struct intel_spi *intel_spi_probe(struct device *dev,
+	struct resource *mem, const struct intel_spi_boardinfo *info)
+{
+	const struct spi_nor_hwcaps hwcaps = {
+		.mask = SNOR_HWCAPS_READ |
+			SNOR_HWCAPS_READ_FAST |
+			SNOR_HWCAPS_PP,
+	};
+	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 ERR_CAST(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.controller_ops = &intel_spi_controller_ops;
+
+	ret = spi_nor_scan(&ispi->nor, NULL, &hwcaps);
+	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_register(&ispi->nor.mtd, &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");