Add support for SFDP (JESD216)

Similar to modules using the opaque programmer framework (e.g. ICH Hardware
Sequencing) this uses a template struct flashchip element in flashchips.c with
a special probe function that fills the obtained values into that struct.

This allows yet unknown SPI chips to be supported (read, erase, write) almost
as if it was already added to flashchips.c.

Documentation used:
http://www.jedec.org/standards-documents/docs/jesd216 (2011-04)
W25Q32BV data sheet Revision F (2011-04-01)
EN25QH16 data sheet Revision F (2011-06-01)
MX25L6436E data sheet Revision 1.8 (2011-12-26)

Tested-by: David Hendricks <dhendrix@google.com>
on W25Q64CV + dediprog
Tested-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
on a 2010 MX25L6436E with preliminary (i.e. incorrect) SFDP implementation + serprog

Thanks also to Michael Karcher for his comments and preliminary review!

Corresponding to flashrom svn r1500.

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
diff --git a/Makefile b/Makefile
index afe2dfb..2d18fc5 100644
--- a/Makefile
+++ b/Makefile
@@ -261,7 +261,7 @@
 CHIP_OBJS = jedec.o stm50flw0x0x.o w39.o w29ee011.o \
 	sst28sf040.o m29f400bt.o 82802ab.o pm49fl00x.o \
 	sst49lfxxxc.o sst_fwhub.o flashchips.o spi.o spi25.o sharplhf00l04.o \
-	a25.o at25.o opaque.o
+	a25.o at25.o opaque.o sfdp.o
 
 LIB_OBJS = layout.o
 
diff --git a/chipdrivers.h b/chipdrivers.h
index a1d0cd9..bd81098 100644
--- a/chipdrivers.h
+++ b/chipdrivers.h
@@ -41,6 +41,7 @@
 int spi_block_erase_d8(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
 int spi_block_erase_60(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
 int spi_block_erase_c7(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
+erasefunc_t *spi_get_erasefn_from_opcode(uint8_t opcode);
 int spi_chip_write_1(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 int spi_chip_write_256(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 int spi_chip_read(struct flashctx *flash, uint8_t *buf, unsigned int start, int unsigned len);
@@ -58,6 +59,9 @@
 int spi_write_chunked(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len, unsigned int chunksize);
 int spi_aai_write(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 
+/* sfdp.c */
+int probe_spi_sfdp(struct flashctx *flash);
+
 /* opaque.c */
 int probe_opaque(struct flashctx *flash);
 int read_opaque(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
diff --git a/flash.h b/flash.h
index 20db343..0dac13d 100644
--- a/flash.h
+++ b/flash.h
@@ -175,6 +175,8 @@
 	struct registered_programmer *pgm;
 };
 
+typedef int (erasefunc_t)(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
+
 #define TEST_UNTESTED	0
 
 #define TEST_OK_PROBE	(1 << 0)
diff --git a/flashchips.c b/flashchips.c
index d789904..b6296c5 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -8885,6 +8885,29 @@
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program */
 	},
+	
+	{
+		.vendor		= "Unknown",
+		.name		= "SFDP-capable chip",
+		.bustype	= BUS_SPI,
+		.manufacture_id	= GENERIC_MANUF_ID,
+		.model_id	= SFDP_DEVICE_ID,
+		/* We present our own "report this" text hence we do not
+		 * want the default "This flash part has status UNTESTED..."
+		 * text to be printed. */
+		.tested		= TEST_OK_PREW,
+		.probe		= probe_spi_sfdp,
+		.unlock		= spi_disable_blockprotect, /* is this safe? */
+		.read		= spi_chip_read,
+		/* FIXME: some vendor extensions define this */
+		.voltage	= {},
+		 /* Everything below will be set by the probing function. */
+		.write		= NULL,
+		.total_size	= 0,
+		.page_size	= 0,
+		.feature_bits	= 0,
+		.block_erasers	= {},
+	},
 
 	{
 		.vendor		= "Programmer",
diff --git a/flashchips.h b/flashchips.h
index 8587ce9..de3c79d 100644
--- a/flashchips.h
+++ b/flashchips.h
@@ -34,8 +34,11 @@
  * SPI parts have 16-bit device IDs if they support RDID.
  */
 
-#define GENERIC_MANUF_ID	0xffff	/* Check if there is a vendor ID */
-#define GENERIC_DEVICE_ID	0xffff	/* Only match the vendor ID */
+#define GENERIC_MANUF_ID	0xFFFF	/* Check if there is a vendor ID */
+#define GENERIC_DEVICE_ID	0xFFFF	/* Only match the vendor ID */
+#define SFDP_DEVICE_ID		0xFFFE
+#define PROGMANUF_ID		0xFFFE	/* dummy ID for opaque chips behind a programmer */
+#define PROGDEV_ID		0x01	/* dummy ID for opaque chips behind a programmer */
 
 #define ALLIANCE_ID		0x52	/* Alliance Semiconductor */
 #define ALLIANCE_AS29F002B	0x34
@@ -646,7 +649,4 @@
 #define WINBOND_W49V002A	0xB0
 #define WINBOND_W49V002FA	0x32
 
-#define PROGMANUF_ID		0xFFFE	/* dummy ID for opaque chips behind a programmer */
-#define PROGDEV_ID		0x01	/* dummy ID for opaque chips behind a programmer */
-
 #endif /* !FLASHCHIPS_H */
diff --git a/flashrom.c b/flashrom.c
index a378e51..cad043b 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -980,13 +980,38 @@
 
 		/* If this is the first chip found, accept it.
 		 * If this is not the first chip found, accept it only if it is
-		 * a non-generic match.
-		 * We could either make chipcount global or provide it as
-		 * parameter, or we assume that startchip==0 means this call to
-		 * probe_flash() is the first one and thus no chip has been
-		 * found before.
+		 * a non-generic match. SFDP and CFI are generic matches.
+		 * startchip==0 means this call to probe_flash() is the first
+		 * one for this programmer interface and thus no other chip has
+		 * been found on this interface.
 		 */
-		if (startchip == 0 || fill_flash->model_id != GENERIC_DEVICE_ID)
+		if (startchip == 0 && fill_flash->model_id == SFDP_DEVICE_ID) {
+			msg_cinfo("===\n"
+				  "SFDP has autodetected a flash chip which is "
+				  "not natively supported by flashrom yet.\n");
+			if (count_usable_erasers(fill_flash) == 0)
+				msg_cinfo("The standard operations read and "
+					  "verify should work, but to support "
+					  "erase, write and all other "
+					  "possible features");
+			else
+				msg_cinfo("All standard operations (read, "
+					  "verify, erase and write) should "
+					  "work, but to support all possible "
+					  "features");
+
+			msg_cinfo(" we need to add them manually.\nYou "
+				  "can help us by mailing us the output of "
+				  "the following command to flashrom@flashrom."
+				  "org: \n'flashrom -VV [plus the "
+				  "-p/--programmer parameter (if needed)]"
+				  "'\nThanks for your help!\n"
+				  "===\n");
+		}
+
+		if (startchip == 0 ||
+		    ((fill_flash->model_id != GENERIC_DEVICE_ID) &&
+		     (fill_flash->model_id != SFDP_DEVICE_ID)))
 			break;
 
 notfound:
diff --git a/sfdp.c b/sfdp.c
new file mode 100644
index 0000000..75dfb5f
--- /dev/null
+++ b/sfdp.c
@@ -0,0 +1,370 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2011-2012 Stefan Tauner
+ *
+ * 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
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include "flash.h"
+#include "spi.h"
+#include "chipdrivers.h"
+
+static int spi_sfdp_read_sfdp_chunk(struct flashctx *flash, uint32_t address, uint8_t *buf, int len)
+{
+	int i, ret;
+	const unsigned char cmd[JEDEC_SFDP_OUTSIZE] = {
+		JEDEC_SFDP,
+		(address >> 16) & 0xff,
+		(address >> 8) & 0xff,
+		(address >> 0) & 0xff,
+		/* FIXME: the following dummy byte explodes on some programmers.
+		 * One possible workaround would be to read the dummy byte
+		 * instead and discard its value.
+		 */
+		0
+	};
+	msg_cspew("%s: addr=0x%x, len=%d, data:\n", __func__, address, len);
+	ret = spi_send_command(flash, sizeof(cmd), len, cmd, buf);
+	for (i = 0; i < len; i++)
+		msg_cspew(" 0x%02x", buf[i]);
+	msg_cspew("\n");
+	return ret;
+}
+
+static int spi_sfdp_read_sfdp(struct flashctx *flash, uint32_t address, uint8_t *buf, int len)
+{
+	/* FIXME: this is wrong. There are different upper bounds for the number
+	 * of bytes to read on the various programmers (even depending on the
+	 * rest of the structure of the transaction).*/
+	int maxstep = 8;
+	int ret = 0;
+	while (len > 0) {
+		int step = min(len, maxstep);
+		ret = spi_sfdp_read_sfdp_chunk(flash, address, buf, step);
+		if (ret)
+			return ret;
+		address += step;
+		buf += step;
+		len -= step;
+	}
+	return ret;
+}
+
+struct sfdp_tbl_hdr {
+	uint8_t id;
+	uint8_t v_minor;
+	uint8_t v_major;
+	uint8_t len;
+	uint32_t ptp; /* 24b pointer */
+};
+
+static int sfdp_add_uniform_eraser(struct flashctx *flash, uint8_t opcode, uint32_t block_size)
+{
+	int i;
+	uint32_t total_size = flash->total_size * 1024;
+	erasefunc_t *erasefn = spi_get_erasefn_from_opcode(opcode);
+
+	if (erasefn == NULL || block_size == 0 || total_size % block_size != 0) {
+		msg_cdbg("%s: invalid input\n", __func__);
+		return 1;
+	}
+
+	for (i = 0; i < NUM_ERASEFUNCTIONS; i++) {
+		struct block_eraser *eraser = &flash->block_erasers[i];
+		/* Check for duplicates (including (some) non-uniform ones). */
+		if (eraser->eraseblocks[0].size == block_size &&
+		    eraser->block_erase == erasefn) {
+			msg_cdbg2("  Tried to add a duplicate block eraser: "
+				  "%d x %d B with opcode 0x%02x\n",
+				  total_size/block_size, block_size, opcode);
+			return 1;
+		}
+		if (eraser->eraseblocks[0].size != 0 || !eraser->block_erase) {
+			msg_cspew("  Block Eraser %d is already occupied.\n",
+				  i);
+			continue;
+		}
+
+		eraser->block_erase = erasefn;
+		eraser->eraseblocks[0].size = block_size;
+		eraser->eraseblocks[0].count = total_size/block_size;
+		msg_cdbg2("  Block eraser %d: %d x %d B with opcode "
+			  "0x%02x\n", i, total_size/block_size, block_size,
+			  opcode);
+		return 0;
+	}
+	msg_cinfo("%s: Not enough space to store another eraser (i=%d)."
+		  " Please report this at flashrom@flashrom.org\n",
+		  __func__, i);
+	return 1;
+}
+
+static int sfdp_fill_flash(struct flashctx *flash, uint8_t *buf, uint16_t len)
+{
+	uint32_t tmp32;
+	uint8_t tmp8;
+	uint32_t total_size; /* in bytes */
+	uint32_t block_size;
+	int dw, j;
+
+	msg_cdbg("Parsing JEDEC flash parameter table... ");
+	if (len != 9 * 4 && len != 4 * 4) {
+		msg_cdbg("%s: len out of spec\n", __func__);
+		return 1;
+	}
+	msg_cdbg2("\n");
+	
+	/* 1. double word */
+	dw = 0;
+	tmp32 = buf[(4 * dw) + 0];
+	tmp32 |= ((unsigned int)buf[(4 * dw) + 1]) << 8;
+	tmp32 |= ((unsigned int)buf[(4 * dw) + 2]) << 16;
+	tmp32 |= ((unsigned int)buf[(4 * dw) + 3]) << 24;
+
+	tmp8 = (tmp32 >> 17) & 0x3;
+	switch (tmp8) {
+	case 0x0:
+		msg_cdbg2("  3-Byte only addressing.\n");
+		break;
+	case 0x1:
+		msg_cdbg2("  3-Byte (and optionally 4-Byte) addressing.\n");
+		break;
+	case 0x2:
+		msg_cdbg("  4-Byte only addressing (not supported by "
+			 "flashrom).\n");
+		return 1;
+	default:
+		msg_cdbg("  Required addressing mode (0x%x) not supported.\n",
+			 tmp8);
+		return 1;
+	}
+
+	msg_cdbg2("  Status register is ");
+	if (tmp32 & (1 << 3)) {
+		msg_cdbg2("volatile and writes to the status register have to "
+			  "be enabled with ");
+		if (tmp32 & (1 << 4)) {
+			flash->feature_bits = FEATURE_WRSR_WREN;
+			msg_cdbg2("WREN (0x06).\n");
+		} else {
+			flash->feature_bits = FEATURE_WRSR_EWSR;
+			msg_cdbg2("EWSR (0x50).\n");
+		}
+	} else
+		msg_cdbg2("non-volatile and the standard does not allow "
+			  "vendors to tell us whether EWSR/WREN is needed for "
+			  "status register writes - assuming EWSR.\n");
+
+	msg_cdbg2("  Write chunk size is ");
+	if (tmp32 & (1 << 2)) {
+		msg_cdbg2("at least 64 B.\n");
+		flash->page_size = 64;
+		flash->write = spi_chip_write_256;
+	} else {
+		msg_cdbg2("1 B only.\n");
+		flash->page_size = 256;
+		flash->write = spi_chip_write_1;
+	}
+
+	if ((tmp32 & 0x3) == 0x1) {
+		sfdp_add_uniform_eraser(flash, (tmp32 >> 8) & 0xFF, 4 * 1024);
+	}
+
+	/* 2. double word */
+	dw = 1;
+	tmp32 = buf[(4 * dw) + 0];
+	tmp32 |= ((unsigned int)buf[(4 * dw) + 1]) << 8;
+	tmp32 |= ((unsigned int)buf[(4 * dw) + 2]) << 16;
+	tmp32 |= ((unsigned int)buf[(4 * dw) + 3]) << 24;
+
+	if (tmp32 & (1 << 31)) {
+		msg_cdbg("Flash chip size >= 4 Gb/512 MB not supported.\n");
+		return 1;
+	}
+	total_size = ((tmp32 & 0x7FFFFFFF) + 1) / 8;
+	flash->total_size = total_size / 1024;
+	msg_cdbg2("  Flash chip size is %d kB.\n", flash->total_size);
+	if (total_size > (1 << 24)) {
+		msg_cdbg("Flash chip size is bigger than what 3-Byte addressing "
+			 "can access.\n");
+		return 1;
+	}
+
+	/* FIXME: double words 3-7 contain unused fast read information */
+
+	if (len == 4 * 4) {
+		msg_cdbg("It seems like this chip supports the preliminary "
+			 "Intel version of SFDP, skipping processing of double "
+			 "words 3-9.\n");
+		goto done;
+	}
+
+	dw = 8;
+	for (j = 0; j < 4; j++) {
+		/* 8 double words from the start + 2 words for every eraser */
+		tmp8 = buf[(4 * dw) + (2 * j)];
+		if (tmp8 == 0) {
+			msg_cdbg2("  Block eraser %d is unused.\n", j);
+			continue;
+		}
+		if (tmp8 >= 31) {
+			msg_cdbg2("  Block size of eraser %d (2^%d) is too big "
+				  "for flashrom.\n", j, tmp8);
+			continue;
+		}
+		block_size = 1 << (tmp8); /* block_size = 2 ^ field */
+
+		tmp8 = buf[(4 * dw) + (2 * j) + 1];
+		sfdp_add_uniform_eraser(flash, tmp8, block_size);
+	}
+
+done:
+	msg_cdbg("done.\n");
+	return 0;
+}
+
+int probe_spi_sfdp(struct flashctx *flash)
+{
+	int ret = 0;
+	uint8_t buf[8];
+	uint32_t tmp32;
+	uint8_t nph;
+	/* need to limit the table loop by comparing i to uint8_t nph hence: */
+	uint16_t i;
+	struct sfdp_tbl_hdr *hdrs;
+	uint8_t *hbuf;
+	uint8_t *tbuf;
+
+	if (spi_sfdp_read_sfdp(flash, 0x00, buf, 4)) {
+		msg_cdbg("Receiving SFDP signature failed.\n");
+		return 0;
+	}
+	tmp32 = buf[0];
+	tmp32 |= ((unsigned int)buf[1]) << 8;
+	tmp32 |= ((unsigned int)buf[2]) << 16;
+	tmp32 |= ((unsigned int)buf[3]) << 24;
+
+	if (tmp32 != 0x50444653) {
+		msg_cdbg2("Signature = 0x%08x (should be 0x50444653)\n", tmp32);
+		msg_cdbg("No SFDP signature found.\n");
+		return 0;
+	}
+
+	if (spi_sfdp_read_sfdp(flash, 0x04, buf, 3)) {
+		msg_cdbg("Receiving SFDP revision and number of parameter "
+			 "headers (NPH) failed. ");
+		return 0;
+	}
+	msg_cdbg2("SFDP revision = %d.%d\n", buf[1], buf[0]);
+	if (buf[1] != 0x01) {
+		msg_cdbg("The chip supports an unknown version of SFDP. "
+			  "Aborting SFDP probe!\n");
+		return 0;
+	}
+	nph = buf[2];
+	msg_cdbg2("SFDP number of parameter headers is %d (NPH = %d).\n",
+		  nph + 1, nph);
+
+	/* Fetch all parameter headers, even if we don't use them all (yet). */
+	hbuf = malloc((nph + 1) * 8);
+	hdrs = malloc((nph + 1) * sizeof(struct sfdp_tbl_hdr));
+	if (hbuf == NULL || hdrs == NULL ) {
+		msg_gerr("Out of memory!\n");
+		goto cleanup_hdrs;
+	}
+	if (spi_sfdp_read_sfdp(flash, 0x08, hbuf, (nph + 1) * 8)) {
+		msg_cdbg("Receiving SFDP parameter table headers failed.\n");
+		goto cleanup_hdrs;
+	}
+
+	for (i = 0; i <= nph; i++) {
+		uint16_t len;
+		hdrs[i].id = hbuf[(8 * i) + 0];
+		hdrs[i].v_minor = hbuf[(8 * i) + 1];
+		hdrs[i].v_major = hbuf[(8 * i) + 2];
+		hdrs[i].len = hbuf[(8 * i) + 3];
+		hdrs[i].ptp = hbuf[(8 * i) + 4];
+		hdrs[i].ptp |= ((unsigned int)hbuf[(8 * i) + 5]) << 8;
+		hdrs[i].ptp |= ((unsigned int)hbuf[(8 * i) + 6]) << 16;
+		msg_cdbg2("\nSFDP parameter table header %d/%d:\n", i, nph);
+		msg_cdbg2("  ID 0x%02x, version %d.%d\n", hdrs[i].id,
+			  hdrs[i].v_major, hdrs[i].v_minor);
+		len = hdrs[i].len * 4;
+		tmp32 = hdrs[i].ptp;
+		msg_cdbg2("  Length %d B, Parameter Table Pointer 0x%06x\n",
+			  len, tmp32);
+
+		if (tmp32 + len >= (1 << 24)) {
+			msg_cdbg("SFDP Parameter Table %d supposedly overflows "
+				  "addressable SFDP area. This most\nprobably "
+				  "indicates a corrupt SFDP parameter table "
+				  "header. Skipping it.\n", i);
+			continue;
+		}
+
+		tbuf = malloc(len);
+		if (tbuf == NULL) {
+			msg_gerr("Out of memory!\n");
+			goto cleanup_hdrs;
+		}
+		if (spi_sfdp_read_sfdp(flash, tmp32, tbuf, len)){
+			msg_cdbg("Fetching SFDP parameter table %d failed.\n",
+				 i);
+			free(tbuf);
+			continue;
+		}
+		msg_cspew("  Parameter table contents:\n");
+		for (tmp32 = 0; tmp32 < len; tmp32++) {
+			if ((tmp32 % 8) == 0) {
+				msg_cspew("    0x%04x: ", tmp32);
+			}
+			msg_cspew(" %02x", buf[tmp32]);
+			if ((tmp32 % 8) == 7) {
+				msg_cspew("\n");
+				continue;
+			}
+			if ((tmp32 % 8) == 3) {
+				msg_cspew(" ");
+				continue;
+			}
+		}
+
+		if (i == 0) { /* Mandatory JEDEC SFDP parameter table */
+			if (hdrs[i].id != 0)
+				msg_cdbg("ID of the mandatory JEDEC SFDP "
+					 "parameter table is not 0 as demanded "
+					 "by JESD216 (warning only).\n");
+
+			if (hdrs[i].v_major != 0x01) {
+				msg_cdbg("The chip contains an unknown "
+					  "version of the JEDEC flash "
+					  "parameters table, skipping it.\n");
+			} else if (len != 9 * 4 && len != 4 * 4) {
+				msg_cdbg("Length of the mandatory JEDEC SFDP "
+					 "parameter table is wrong (%d B), "
+					 "skipping it.\n", len);
+			} else if (sfdp_fill_flash(flash, tbuf, len) == 0)
+				ret = 1;
+		}
+		free(tbuf);
+	}
+
+cleanup_hdrs:
+	free(hdrs);
+	free(hbuf);
+	return ret;
+}
diff --git a/spi.h b/spi.h
index b908603..5f07eae 100644
--- a/spi.h
+++ b/spi.h
@@ -40,6 +40,11 @@
 #define JEDEC_REMS_OUTSIZE	0x04
 #define JEDEC_REMS_INSIZE	0x02
 
+/* Read Serial Flash Discoverable Parameters (SFDP) */
+#define JEDEC_SFDP		0x5a
+#define JEDEC_SFDP_OUTSIZE	0x05	/* 8b op, 24b addr, 8b dummy */
+/*      JEDEC_SFDP_INSIZE : any length */
+
 /* Read Electronic Signature */
 #define JEDEC_RES		0xab
 #define JEDEC_RES_OUTSIZE	0x04
diff --git a/spi25.c b/spi25.c
index 3ce7f08..b7e8189 100644
--- a/spi25.c
+++ b/spi25.c
@@ -720,6 +720,32 @@
 	return spi_chip_erase_c7(flash);
 }
 
+erasefunc_t *spi_get_erasefn_from_opcode(uint8_t opcode)
+{
+	switch(opcode){
+	case 0xff:
+	case 0x00:
+		/* Not specified, assuming "not supported". */
+		return NULL;
+	case 0x20:
+		return &spi_block_erase_20;
+	case 0x52:
+		return &spi_block_erase_52;
+	case 0x60:
+		return &spi_block_erase_60;
+	case 0xc7:
+		return &spi_block_erase_c7;
+	case 0xd7:
+		return &spi_block_erase_d7;
+	case 0xd8:
+		return &spi_block_erase_d8;
+	default:
+		msg_cinfo("%s: unknown erase opcode (0x%02x). Please report "
+			  "this at flashrom@flashrom.org\n", __func__, opcode);
+		return NULL;
+	}
+}
+
 int spi_write_status_enable(struct flashctx *flash)
 {
 	static const unsigned char cmd[JEDEC_EWSR_OUTSIZE] = { JEDEC_EWSR };