soc/intel/skylake: Use Broadwell as comparision base for Skylake SOC

Use the Broadwell implementation as the comparison base for Skylake.

BRANCH=none
BUG=None
TEST=None

Change-Id: I22eb55ea89eb0d6883f98e4c72a6d243e819e6d8
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: http://review.coreboot.org/10340
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

1 files changed, 680 insertions, 0 deletions

diff --git a/src/soc/intel/skylake/spi.c b/src/soc/intel/skylake/spi.c
new file mode 100644
index 0000000000..36558a1db9
--- /dev/null
+++ b/src/soc/intel/skylake/spi.c
@@ -0,0 +1,680 @@
+/*
+ * Copyright (C) 2014 Google Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/* This file is derived from the flashrom project. */
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <bootstate.h>
+#include <delay.h>
+#include <arch/io.h>
+#include <console/console.h>
+#include <device/pci_ids.h>
+#include <spi-generic.h>
+#include <soc/pci_devs.h>
+#include <soc/rcba.h>
+#include <soc/spi.h>
+
+#ifdef __SMM__
+#define pci_read_config_byte(dev, reg, targ)\
+	*(targ) = pci_read_config8(dev, reg)
+#define pci_read_config_word(dev, reg, targ)\
+	*(targ) = pci_read_config16(dev, reg)
+#define pci_read_config_dword(dev, reg, targ)\
+	*(targ) = pci_read_config32(dev, reg)
+#define pci_write_config_byte(dev, reg, val)\
+	pci_write_config8(dev, reg, val)
+#define pci_write_config_word(dev, reg, val)\
+	pci_write_config16(dev, reg, val)
+#define pci_write_config_dword(dev, reg, val)\
+	pci_write_config32(dev, reg, val)
+#else /* !__SMM__ */
+#include <device/device.h>
+#include <device/pci.h>
+#define pci_read_config_byte(dev, reg, targ)\
+	*(targ) = pci_read_config8(dev, reg)
+#define pci_read_config_word(dev, reg, targ)\
+	*(targ) = pci_read_config16(dev, reg)
+#define pci_read_config_dword(dev, reg, targ)\
+	*(targ) = pci_read_config32(dev, reg)
+#define pci_write_config_byte(dev, reg, val)\
+	pci_write_config8(dev, reg, val)
+#define pci_write_config_word(dev, reg, val)\
+	pci_write_config16(dev, reg, val)
+#define pci_write_config_dword(dev, reg, val)\
+	pci_write_config32(dev, reg, val)
+#endif /* !__SMM__ */
+
+typedef struct spi_slave ich_spi_slave;
+
+static int ichspi_lock = 0;
+
+typedef struct ich9_spi_regs {
+	uint32_t bfpr;
+	uint16_t hsfs;
+	uint16_t hsfc;
+	uint32_t faddr;
+	uint32_t _reserved0;
+	uint32_t fdata[16];
+	uint32_t frap;
+	uint32_t freg[5];
+	uint32_t _reserved1[3];
+	uint32_t pr[5];
+	uint32_t _reserved2[2];
+	uint8_t ssfs;
+	uint8_t ssfc[3];
+	uint16_t preop;
+	uint16_t optype;
+	uint8_t opmenu[8];
+	uint32_t bbar;
+	uint8_t _reserved3[12];
+	uint32_t fdoc;
+	uint32_t fdod;
+	uint8_t _reserved4[8];
+	uint32_t afc;
+	uint32_t lvscc;
+	uint32_t uvscc;
+	uint8_t _reserved5[4];
+	uint32_t fpb;
+	uint8_t _reserved6[28];
+	uint32_t srdl;
+	uint32_t srdc;
+	uint32_t srd;
+} __attribute__((packed)) ich9_spi_regs;
+
+typedef struct ich_spi_controller {
+	int locked;
+
+	uint8_t *opmenu;
+	int menubytes;
+	uint16_t *preop;
+	uint16_t *optype;
+	uint32_t *addr;
+	uint8_t *data;
+	unsigned databytes;
+	uint8_t *status;
+	uint16_t *control;
+	uint32_t *bbar;
+} ich_spi_controller;
+
+static ich_spi_controller cntlr;
+
+enum {
+	SPIS_SCIP =		0x0001,
+	SPIS_GRANT =		0x0002,
+	SPIS_CDS =		0x0004,
+	SPIS_FCERR =		0x0008,
+	SSFS_AEL =		0x0010,
+	SPIS_LOCK =		0x8000,
+	SPIS_RESERVED_MASK =	0x7ff0,
+	SSFS_RESERVED_MASK =	0x7fe2
+};
+
+enum {
+	SPIC_SCGO =		0x000002,
+	SPIC_ACS =		0x000004,
+	SPIC_SPOP =		0x000008,
+	SPIC_DBC =		0x003f00,
+	SPIC_DS =		0x004000,
+	SPIC_SME =		0x008000,
+	SSFC_SCF_MASK =		0x070000,
+	SSFC_RESERVED =		0xf80000
+};
+
+enum {
+	HSFS_FDONE =		0x0001,
+	HSFS_FCERR =		0x0002,
+	HSFS_AEL =		0x0004,
+	HSFS_BERASE_MASK =	0x0018,
+	HSFS_BERASE_SHIFT =	3,
+	HSFS_SCIP =		0x0020,
+	HSFS_FDOPSS =		0x2000,
+	HSFS_FDV =		0x4000,
+	HSFS_FLOCKDN =		0x8000
+};
+
+enum {
+	HSFC_FGO =		0x0001,
+	HSFC_FCYCLE_MASK =	0x0006,
+	HSFC_FCYCLE_SHIFT =	1,
+	HSFC_FDBC_MASK =	0x3f00,
+	HSFC_FDBC_SHIFT =	8,
+	HSFC_FSMIE =		0x8000
+};
+
+enum {
+	SPI_OPCODE_TYPE_READ_NO_ADDRESS =	0,
+	SPI_OPCODE_TYPE_WRITE_NO_ADDRESS =	1,
+	SPI_OPCODE_TYPE_READ_WITH_ADDRESS =	2,
+	SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS =	3
+};
+
+#if CONFIG_DEBUG_SPI_FLASH
+
+static u8 readb_(const void *addr)
+{
+	u8 v = read8(addr);
+	printk(BIOS_DEBUG, "read %2.2x from %4.4x\n",
+	       v, ((unsigned) addr & 0xffff) - 0xf020);
+	return v;
+}
+
+static u16 readw_(const void *addr)
+{
+	u16 v = read16(addr);
+	printk(BIOS_DEBUG, "read %4.4x from %4.4x\n",
+	       v, ((unsigned) addr & 0xffff) - 0xf020);
+	return v;
+}
+
+static u32 readl_(const void *addr)
+{
+	u32 v = read32(addr);
+	printk(BIOS_DEBUG, "read %8.8x from %4.4x\n",
+	       v, ((unsigned) addr & 0xffff) - 0xf020);
+	return v;
+}
+
+static void writeb_(u8 b, const void *addr)
+{
+	write8(addr, b);
+	printk(BIOS_DEBUG, "wrote %2.2x to %4.4x\n",
+	       b, ((unsigned) addr & 0xffff) - 0xf020);
+}
+
+static void writew_(u16 b, const void *addr)
+{
+	write16(addr, b);
+	printk(BIOS_DEBUG, "wrote %4.4x to %4.4x\n",
+	       b, ((unsigned) addr & 0xffff) - 0xf020);
+}
+
+static void writel_(u32 b, const void *addr)
+{
+	write32(addr, b);
+	printk(BIOS_DEBUG, "wrote %8.8x to %4.4x\n",
+	       b, ((unsigned) addr & 0xffff) - 0xf020);
+}
+
+#else /* CONFIG_DEBUG_SPI_FLASH ^^^ enabled  vvv NOT enabled */
+
+#define readb_(a) read8(a)
+#define readw_(a) read16(a)
+#define readl_(a) read32(a)
+#define writeb_(val, addr) write8(addr, val)
+#define writew_(val, addr) write16(addr, val)
+#define writel_(val, addr) write32(addr, val)
+
+#endif  /* CONFIG_DEBUG_SPI_FLASH ^^^ NOT enabled */
+
+static void write_reg(const void *value, void *dest, uint32_t size)
+{
+	const uint8_t *bvalue = value;
+	uint8_t *bdest = dest;
+
+	while (size >= 4) {
+		writel_(*(const uint32_t *)bvalue, bdest);
+		bdest += 4; bvalue += 4; size -= 4;
+	}
+	while (size) {
+		writeb_(*bvalue, bdest);
+		bdest++; bvalue++; size--;
+	}
+}
+
+static void read_reg(const void *src, void *value, uint32_t size)
+{
+	const uint8_t *bsrc = src;
+	uint8_t *bvalue = value;
+
+	while (size >= 4) {
+		*(uint32_t *)bvalue = readl_(bsrc);
+		bsrc += 4; bvalue += 4; size -= 4;
+	}
+	while (size) {
+		*bvalue = readb_(bsrc);
+		bsrc++; bvalue++; size--;
+	}
+}
+
+static void ich_set_bbar(uint32_t minaddr)
+{
+	const uint32_t bbar_mask = 0x00ffff00;
+	uint32_t ichspi_bbar;
+
+	minaddr &= bbar_mask;
+	ichspi_bbar = readl_(cntlr.bbar) & ~bbar_mask;
+	ichspi_bbar |= minaddr;
+	writel_(ichspi_bbar, cntlr.bbar);
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs)
+{
+	ich_spi_slave *slave = malloc(sizeof(*slave));
+
+	if (!slave) {
+		printk(BIOS_DEBUG, "ICH SPI: Bad allocation\n");
+		return NULL;
+	}
+
+	memset(slave, 0, sizeof(*slave));
+
+	slave->bus = bus;
+	slave->cs = cs;
+	return slave;
+}
+
+void spi_init(void)
+{
+	uint8_t *rcrb; /* Root Complex Register Block */
+	uint32_t rcba; /* Root Complex Base Address */
+	uint8_t bios_cntl;
+	device_t dev = PCH_DEV_LPC;
+	ich9_spi_regs *ich9_spi;
+
+	pci_read_config_dword(dev, 0xf0, &rcba);
+	/* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable. */
+	rcrb = (uint8_t *)(rcba & 0xffffc000);
+	ich9_spi = (ich9_spi_regs *)(rcrb + 0x3800);
+	ichspi_lock = readw_(&ich9_spi->hsfs) & HSFS_FLOCKDN;
+	cntlr.opmenu = ich9_spi->opmenu;
+	cntlr.menubytes = sizeof(ich9_spi->opmenu);
+	cntlr.optype = &ich9_spi->optype;
+	cntlr.addr = &ich9_spi->faddr;
+	cntlr.data = (uint8_t *)ich9_spi->fdata;
+	cntlr.databytes = sizeof(ich9_spi->fdata);
+	cntlr.status = &ich9_spi->ssfs;
+	cntlr.control = (uint16_t *)ich9_spi->ssfc;
+	cntlr.bbar = &ich9_spi->bbar;
+	cntlr.preop = &ich9_spi->preop;
+	ich_set_bbar(0);
+
+	/* Disable the BIOS write protect so write commands are allowed. */
+	pci_read_config_byte(dev, 0xdc, &bios_cntl);
+	bios_cntl &= ~(1 << 5);
+	pci_write_config_byte(dev, 0xdc, bios_cntl | 0x1);
+}
+
+#if ENV_RAMSTAGE
+static void spi_init_cb(void *unused)
+{
+	spi_init();
+}
+
+BOOT_STATE_INIT_ENTRY(BS_DEV_INIT, BS_ON_ENTRY, spi_init_cb, NULL);
+#endif
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	/* Handled by ICH automatically. */
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	/* Handled by ICH automatically. */
+}
+
+typedef struct spi_transaction {
+	const uint8_t *out;
+	uint32_t bytesout;
+	uint8_t *in;
+	uint32_t bytesin;
+	uint8_t type;
+	uint8_t opcode;
+	uint32_t offset;
+} spi_transaction;
+
+static inline void spi_use_out(spi_transaction *trans, unsigned bytes)
+{
+	trans->out += bytes;
+	trans->bytesout -= bytes;
+}
+
+static inline void spi_use_in(spi_transaction *trans, unsigned bytes)
+{
+	trans->in += bytes;
+	trans->bytesin -= bytes;
+}
+
+static void spi_setup_type(spi_transaction *trans)
+{
+	trans->type = 0xFF;
+
+	/* Try to guess spi type from read/write sizes. */
+	if (trans->bytesin == 0) {
+		if (trans->bytesout > 4)
+			/*
+			 * If bytesin = 0 and bytesout > 4, we presume this is
+			 * a write data operation, which is accompanied by an
+			 * address.
+			 */
+			trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
+		else
+			trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
+		return;
+	}
+
+	if (trans->bytesout == 1) { /* and bytesin is > 0 */
+		trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
+		return;
+	}
+
+	if (trans->bytesout == 4) { /* and bytesin is > 0 */
+		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
+	}
+
+	/* Fast read command is called with 5 bytes instead of 4 */
+	if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
+		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
+		--trans->bytesout;
+	}
+}
+
+static int spi_setup_opcode(spi_transaction *trans)
+{
+	uint16_t optypes;
+	uint8_t opmenu[cntlr.menubytes];
+
+	trans->opcode = trans->out[0];
+	spi_use_out(trans, 1);
+	if (!ichspi_lock) {
+		/* The lock is off, so just use index 0. */
+		writeb_(trans->opcode, cntlr.opmenu);
+		optypes = readw_(cntlr.optype);
+		optypes = (optypes & 0xfffc) | (trans->type & 0x3);
+		writew_(optypes, cntlr.optype);
+		return 0;
+	} else {
+		/* The lock is on. See if what we need is on the menu. */
+		uint8_t optype;
+		uint16_t opcode_index;
+
+		/* Write Enable is handled as atomic prefix */
+		if (trans->opcode == SPI_OPCODE_WREN)
+			return 0;
+
+		read_reg(cntlr.opmenu, opmenu, sizeof(opmenu));
+		for (opcode_index = 0; opcode_index < cntlr.menubytes;
+				opcode_index++) {
+			if (opmenu[opcode_index] == trans->opcode)
+				break;
+		}
+
+		if (opcode_index == cntlr.menubytes) {
+			printk(BIOS_DEBUG, "ICH SPI: Opcode %x not found\n",
+				trans->opcode);
+			return -1;
+		}
+
+		optypes = readw_(cntlr.optype);
+		optype = (optypes >> (opcode_index * 2)) & 0x3;
+		if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
+			optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
+			trans->bytesout >= 3) {
+			/* We guessed wrong earlier. Fix it up. */
+			trans->type = optype;
+		}
+		if (optype != trans->type) {
+			printk(BIOS_DEBUG, "ICH SPI: Transaction doesn't fit type %d\n",
+				optype);
+			return -1;
+		}
+		return opcode_index;
+	}
+}
+
+static int spi_setup_offset(spi_transaction *trans)
+{
+	/* Separate the SPI address and data. */
+	switch (trans->type) {
+	case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
+	case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
+		return 0;
+	case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
+	case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
+		trans->offset = ((uint32_t)trans->out[0] << 16) |
+				((uint32_t)trans->out[1] << 8) |
+				((uint32_t)trans->out[2] << 0);
+		spi_use_out(trans, 3);
+		return 1;
+	default:
+		printk(BIOS_DEBUG, "Unrecognized SPI transaction type %#x\n", trans->type);
+		return -1;
+	}
+}
+
+/*
+ * Wait for up to 60ms til status register bit(s) turn 1 (in case wait_til_set
+ * below is True) or 0. In case the wait was for the bit(s) to set - write
+ * those bits back, which would cause resetting them.
+ *
+ * Return the last read status value on success or -1 on failure.
+ */
+static int ich_status_poll(u16 bitmask, int wait_til_set)
+{
+	int timeout = 6000; /* This will result in 60 ms */
+	u16 status = 0;
+
+	while (timeout--) {
+		status = readw_(cntlr.status);
+		if (wait_til_set ^ ((status & bitmask) == 0)) {
+			if (wait_til_set)
+				writew_((status & bitmask), cntlr.status);
+			return status;
+		}
+		udelay(10);
+	}
+
+	printk(BIOS_DEBUG, "ICH SPI: SCIP timeout, read %x, expected %x\n",
+		status, bitmask);
+	return -1;
+}
+
+unsigned int spi_crop_chunk(unsigned int cmd_len, unsigned int buf_len)
+{
+	return min(cntlr.databytes, buf_len);
+}
+
+int spi_xfer(struct spi_slave *slave, const void *dout,
+		unsigned int bytesout, void *din, unsigned int bytesin)
+{
+	uint16_t control;
+	int16_t opcode_index;
+	int with_address;
+	int status;
+
+	spi_transaction trans = {
+		dout, bytesout,
+		din, bytesin,
+		0xff, 0xff, 0
+	};
+
+	/* There has to always at least be an opcode. */
+	if (!bytesout || !dout) {
+		printk(BIOS_DEBUG, "ICH SPI: No opcode for transfer\n");
+		return -1;
+	}
+	/* Make sure if we read something we have a place to put it. */
+	if (bytesin != 0 && !din) {
+		printk(BIOS_DEBUG, "ICH SPI: Read but no target buffer\n");
+		return -1;
+	}
+
+	if (ich_status_poll(SPIS_SCIP, 0) == -1)
+		return -1;
+
+	writew_(SPIS_CDS | SPIS_FCERR, cntlr.status);
+
+	spi_setup_type(&trans);
+	if ((opcode_index = spi_setup_opcode(&trans)) < 0)
+		return -1;
+	if ((with_address = spi_setup_offset(&trans)) < 0)
+		return -1;
+
+	if (trans.opcode == SPI_OPCODE_WREN) {
+		/*
+		 * Treat Write Enable as Atomic Pre-Op if possible
+		 * in order to prevent the Management Engine from
+		 * issuing a transaction between WREN and DATA.
+		 */
+		if (!ichspi_lock)
+			writew_(trans.opcode, cntlr.preop);
+		return 0;
+	}
+
+	/* Preset control fields */
+	control = SPIC_SCGO | ((opcode_index & 0x07) << 4);
+
+	/* Issue atomic preop cycle if needed */
+	if (readw_(cntlr.preop))
+		control |= SPIC_ACS;
+
+	if (!trans.bytesout && !trans.bytesin) {
+		/* SPI addresses are 24 bit only */
+		if (with_address)
+			writel_(trans.offset & 0x00FFFFFF, cntlr.addr);
+
+		/*
+		 * This is a 'no data' command (like Write Enable), its
+		 * bytesout size was 1, decremented to zero while executing
+		 * spi_setup_opcode() above. Tell the chip to send the
+		 * command.
+		 */
+		writew_(control, cntlr.control);
+
+		/* wait for the result */
+		status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
+		if (status == -1)
+			return -1;
+
+		if (status & SPIS_FCERR) {
+			printk(BIOS_DEBUG, "ICH SPI: Command transaction error\n");
+			return -1;
+		}
+
+		return 0;
+	}
+
+	/*
+	 * Check if this is a write command attempting to transfer more bytes
+	 * than the controller can handle. Iterations for writes are not
+	 * supported here because each SPI write command needs to be preceded
+	 * and followed by other SPI commands, and this sequence is controlled
+	 * by the SPI chip driver.
+	 */
+	if (trans.bytesout > cntlr.databytes) {
+		printk(BIOS_DEBUG, "ICH SPI: Too much to write. Does your SPI chip driver use"
+		     " CONTROLLER_PAGE_LIMIT?\n");
+		return -1;
+	}
+
+	/*
+	 * Read or write up to databytes bytes at a time until everything has
+	 * been sent.
+	 */
+	while (trans.bytesout || trans.bytesin) {
+		uint32_t data_length;
+
+		/* SPI addresses are 24 bit only */
+		/* http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/pentium-n3520-j2850-celeron-n2920-n2820-n2815-n2806-j1850-j1750-datasheet.pdf */
+		writel_(trans.offset & 0x00FFFFFF, cntlr.addr);
+
+		if (trans.bytesout)
+			data_length = min(trans.bytesout, cntlr.databytes);
+		else
+			data_length = min(trans.bytesin, cntlr.databytes);
+
+		/* Program data into FDATA0 to N */
+		if (trans.bytesout) {
+			write_reg(trans.out, cntlr.data, data_length);
+			spi_use_out(&trans, data_length);
+			if (with_address)
+				trans.offset += data_length;
+		}
+
+		/* Add proper control fields' values */
+		control &= ~((cntlr.databytes - 1) << 8);
+		control |= SPIC_DS;
+		control |= (data_length - 1) << 8;
+
+		/* write it */
+		writew_(control, cntlr.control);
+
+		/* Wait for Cycle Done Status or Flash Cycle Error. */
+		status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
+		if (status == -1)
+			return -1;
+
+		if (status & SPIS_FCERR) {
+			printk(BIOS_DEBUG, "ICH SPI: Data transaction error\n");
+			return -1;
+		}
+
+		if (trans.bytesin) {
+			read_reg(cntlr.data, trans.in, data_length);
+			spi_use_in(&trans, data_length);
+			if (with_address)
+				trans.offset += data_length;
+		}
+	}
+
+	/* Clear atomic preop now that xfer is done */
+	writew_(0, cntlr.preop);
+
+	return 0;
+}
+
+/* Use first empty Protected Range Register to cover region of flash */
+int spi_flash_protect(u32 start, u32 size)
+{
+	u32 end = start + size - 1;
+	u32 reg;
+	int prr;
+
+	/* Find first empty PRR */
+	for (prr = 0; prr < SPI_PRR_MAX; prr++) {
+		reg = SPIBAR32(SPI_PRR(prr));
+		if (reg == 0)
+			break;
+	}
+	if (prr >= SPI_PRR_MAX) {
+		printk(BIOS_ERR, "ERROR: No SPI PRR free!\n");
+		return -1;
+	}
+
+	/* Set protected range base and limit */
+	reg = ((end >> SPI_PRR_SHIFT) & SPI_PRR_MASK);
+	reg <<= SPI_PRR_LIMIT_SHIFT;
+	reg |= ((start >> SPI_PRR_SHIFT) & SPI_PRR_MASK);
+	reg |= SPI_PRR_WPE;
+
+	/* Set the PRR register and verify it is protected */
+	SPIBAR32(SPI_PRR(prr)) = reg;
+	reg = SPIBAR32(SPI_PRR(prr));
+	if (!(reg & SPI_PRR_WPE)) {
+		printk(BIOS_ERR, "ERROR: Unable to set SPI PRR %d\n", prr);
+		return -1;
+	}
+
+	printk(BIOS_INFO, "%s: PRR %d is enabled for range 0x%08x-0x%08x\n",
+	       __func__, prr, start, end);
+	return 0;
+}