Improve SPI status register pretty printing

 - Move all functions related to SPI status registers to a new file
   spi25_statusreg.c. This includes the generic as well as the
   SST-specific functions from spi25.c and the chip-specific functions
   from a25.c and at25.c.
 - introduce helper functions
    * spi_prettyprint_status_register_hex()
    * spi_prettyprint_status_register_bpl()
    * spi_prettyprint_status_register_plain()
   Use the latter on every compatible flash chip that has no better printlock
   function set and get rid of the implicit pretty printing in the SPI probing
   functions.
 - remove
    * spi_prettyprint_status_register_common()
    * spi_prettyprint_status_register_amic_a25lq032() because it can be fully
      substituted with spi_prettyprint_status_register_amic_a25l032().
    * spi_prettyprint_status_register() (old switch, no longer needed)
 - promote and export
    * spi_prettyprint_status_register_amic_a25l05p() as spi_prettyprint_status_register_default_bp1().
    * spi_prettyprint_status_register_amic_a25l40p() as spi_prettyprint_status_register_default_bp2().
    * spi_prettyprint_status_register_st_m25p() as spi_prettyprint_status_register_default_bp3().
 - add #define TEST_BAD_REW and use it for a number of Atmel chips which
   had only TEST_BAD_READ set even though they dont have erasers or a write
   function set.

Corresponding to flashrom svn r1634.

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/spi25_statusreg.c b/spi25_statusreg.c
new file mode 100644
index 0000000..2931fc0
--- /dev/null
+++ b/spi25_statusreg.c
@@ -0,0 +1,591 @@
+/*
+ * This file is part of the flashrom project.
+ * It handles everything related to status registers of the JEDEC family 25.
+ *
+ * Copyright (C) 2007, 2008, 2009, 2010 Carl-Daniel Hailfinger
+ * Copyright (C) 2008 coresystems GmbH
+ * Copyright (C) 2008 Ronald Hoogenboom <ronald@zonnet.nl>
+ * Copyright (C) 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 "flash.h"
+#include "chipdrivers.h"
+#include "spi.h"
+
+/* === Generic functions === */
+int spi_write_status_enable(struct flashctx *flash)
+{
+	static const unsigned char cmd[JEDEC_EWSR_OUTSIZE] = { JEDEC_EWSR };
+	int result;
+
+	/* Send EWSR (Enable Write Status Register). */
+	result = spi_send_command(flash, sizeof(cmd), JEDEC_EWSR_INSIZE, cmd, NULL);
+
+	if (result)
+		msg_cerr("%s failed\n", __func__);
+
+	return result;
+}
+
+static int spi_write_status_register_flag(struct flashctx *flash, int status, const unsigned char enable_opcode)
+{
+	int result;
+	int i = 0;
+	/*
+	 * WRSR requires either EWSR or WREN depending on chip type.
+	 * The code below relies on the fact hat EWSR and WREN have the same
+	 * INSIZE and OUTSIZE.
+	 */
+	struct spi_command cmds[] = {
+	{
+		.writecnt	= JEDEC_WREN_OUTSIZE,
+		.writearr	= (const unsigned char[]){ enable_opcode },
+		.readcnt	= 0,
+		.readarr	= NULL,
+	}, {
+		.writecnt	= JEDEC_WRSR_OUTSIZE,
+		.writearr	= (const unsigned char[]){ JEDEC_WRSR, (unsigned char) status },
+		.readcnt	= 0,
+		.readarr	= NULL,
+	}, {
+		.writecnt	= 0,
+		.writearr	= NULL,
+		.readcnt	= 0,
+		.readarr	= NULL,
+	}};
+
+	result = spi_send_multicommand(flash, cmds);
+	if (result) {
+		msg_cerr("%s failed during command execution\n", __func__);
+		/* No point in waiting for the command to complete if execution
+		 * failed.
+		 */
+		return result;
+	}
+	/* WRSR performs a self-timed erase before the changes take effect.
+	 * This may take 50-85 ms in most cases, and some chips apparently
+	 * allow running RDSR only once. Therefore pick an initial delay of
+	 * 100 ms, then wait in 10 ms steps until a total of 5 s have elapsed.
+	 */
+	programmer_delay(100 * 1000);
+	while (spi_read_status_register(flash) & SPI_SR_WIP) {
+		if (++i > 490) {
+			msg_cerr("Error: WIP bit after WRSR never cleared\n");
+			return TIMEOUT_ERROR;
+		}
+		programmer_delay(10 * 1000);
+	}
+	return 0;
+}
+
+int spi_write_status_register(struct flashctx *flash, int status)
+{
+	int feature_bits = flash->chip->feature_bits;
+	int ret = 1;
+
+	if (!(feature_bits & (FEATURE_WRSR_WREN | FEATURE_WRSR_EWSR))) {
+		msg_cdbg("Missing status register write definition, assuming "
+			 "EWSR is needed\n");
+		feature_bits |= FEATURE_WRSR_EWSR;
+	}
+	if (feature_bits & FEATURE_WRSR_WREN)
+		ret = spi_write_status_register_flag(flash, status, JEDEC_WREN);
+	if (ret && (feature_bits & FEATURE_WRSR_EWSR))
+		ret = spi_write_status_register_flag(flash, status, JEDEC_EWSR);
+	return ret;
+}
+
+uint8_t spi_read_status_register(struct flashctx *flash)
+{
+	static const unsigned char cmd[JEDEC_RDSR_OUTSIZE] = { JEDEC_RDSR };
+	/* FIXME: No workarounds for driver/hardware bugs in generic code. */
+	unsigned char readarr[2]; /* JEDEC_RDSR_INSIZE=1 but wbsio needs 2 */
+	int ret;
+
+	/* Read Status Register */
+	ret = spi_send_command(flash, sizeof(cmd), sizeof(readarr), cmd, readarr);
+	if (ret)
+		msg_cerr("RDSR failed!\n");
+
+	return readarr[0];
+}
+
+/* A generic brute-force block protection disable works like this:
+ * Write 0x00 to the status register. Check if any locks are still set (that
+ * part is chip specific). Repeat once.
+ */
+int spi_disable_blockprotect(struct flashctx *flash)
+{
+	uint8_t status;
+	int result;
+
+	status = spi_read_status_register(flash);
+	/* If block protection is disabled, stop here. */
+	if ((status & 0x3c) == 0)
+		return 0;
+
+	msg_cdbg("Some block protection in effect, disabling... ");
+	result = spi_write_status_register(flash, status & ~0x3c);
+	if (result) {
+		msg_cerr("spi_write_status_register failed.\n");
+		return result;
+	}
+	status = spi_read_status_register(flash);
+	if ((status & 0x3c) != 0) {
+		msg_cerr("Block protection could not be disabled!\n");
+		return 1;
+	}
+	msg_cdbg("done.\n");
+	return 0;
+}
+
+static void spi_prettyprint_status_register_hex(uint8_t status)
+{
+	msg_cdbg("Chip status register is 0x%02x.\n", status);
+}
+
+/* Common highest bit: Status Register Write Disable (SRWD). */
+static void spi_prettyprint_status_register_srwd(uint8_t status)
+{
+	msg_cdbg("Chip status register: Status Register Write Disable (SRWD) is %sset\n",
+		 (status & (1 << 7)) ? "" : "not ");
+}
+
+/* Common highest bit: Block Protect Write Disable (BPL). */
+static void spi_prettyprint_status_register_bpl(uint8_t status)
+{
+	msg_cdbg("Chip status register: Block Protect Write Disable (BPL) is %sset\n",
+		 (status & (1 << 7)) ? "" : "not ");
+}
+
+/* Common lowest 2 bits: WEL and WIP. */
+static void spi_prettyprint_status_register_welwip(uint8_t status)
+{
+	msg_cdbg("Chip status register: Write Enable Latch (WEL) is %sset\n",
+		 (status & (1 << 1)) ? "" : "not ");
+	msg_cdbg("Chip status register: Write In Progress (WIP/BUSY) is %sset\n",
+		 (status & (1 << 0)) ? "" : "not ");
+}
+
+/* Common block protection (BP) bits. */
+static void spi_prettyprint_status_register_bp(uint8_t status, int bp)
+{
+	switch (bp) {
+	/* Fall through. */
+	case 4:
+		msg_cdbg("Chip status register: Block Protect 4 (BP4) is %sset\n",
+			 (status & (1 << 5)) ? "" : "not ");
+	case 3:
+		msg_cdbg("Chip status register: Block Protect 3 (BP3) is %sset\n",
+			 (status & (1 << 5)) ? "" : "not ");
+	case 2:
+		msg_cdbg("Chip status register: Block Protect 2 (BP2) is %sset\n",
+			 (status & (1 << 4)) ? "" : "not ");
+	case 1:
+		msg_cdbg("Chip status register: Block Protect 1 (BP1) is %sset\n",
+			 (status & (1 << 3)) ? "" : "not ");
+	case 0:
+		msg_cdbg("Chip status register: Block Protect 0 (BP0) is %sset\n",
+			 (status & (1 << 2)) ? "" : "not ");
+	}
+}
+
+/* Unnamed bits. */
+static void spi_prettyprint_status_register_bit(uint8_t status, int bit)
+{
+	msg_cdbg("Chip status register: Bit %i is %sset\n", bit, (status & (1 << bit)) ? "" : "not ");
+}
+
+int spi_prettyprint_status_register_plain(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+	return 0;
+}
+
+/* Works for many chips of the
+ * AMIC A25L series
+ * and MX MX25L512
+ */
+int spi_prettyprint_status_register_default_bp1(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_srwd(status);
+	spi_prettyprint_status_register_bit(status, 6);
+	spi_prettyprint_status_register_bit(status, 5);
+	spi_prettyprint_status_register_bit(status, 4);
+	spi_prettyprint_status_register_bp(status, 1);
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+/* Works for many chips of the
+ * AMIC A25L series
+ */
+int spi_prettyprint_status_register_default_bp2(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_srwd(status);
+	spi_prettyprint_status_register_bit(status, 6);
+	spi_prettyprint_status_register_bit(status, 5);
+	spi_prettyprint_status_register_bp(status, 2);
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+/* Works for many chips of the
+ * ST M25P series
+ * MX MX25L series
+ */
+int spi_prettyprint_status_register_default_bp3(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_srwd(status);
+	spi_prettyprint_status_register_bit(status, 6);
+	spi_prettyprint_status_register_bp(status, 3);
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+/* === Amic ===
+ * FIXME: spi_disable_blockprotect is incorrect but works fine for chips using
+ * spi_prettyprint_status_register_default_bp1 or
+ * spi_prettyprint_status_register_default_bp2.
+ * FIXME: spi_disable_blockprotect is incorrect and will fail for chips using
+ * spi_prettyprint_status_register_amic_a25l032 if those have locks controlled
+ * by the second status register.
+ */
+
+int spi_prettyprint_status_register_amic_a25l032(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_srwd(status);
+	msg_cdbg("Chip status register: Sector Protect Size (SEC) is %i KB\n", (status & (1 << 6)) ? 4 : 64);
+	msg_cdbg("Chip status register: Top/Bottom (TB) is %s\n", (status & (1 << 5)) ? "bottom" : "top");
+	spi_prettyprint_status_register_bp(status, 2);
+	spi_prettyprint_status_register_welwip(status);
+	msg_cdbg("Chip status register 2 is NOT decoded!\n");
+	return 0;
+}
+
+/* === Atmel === */
+
+static void spi_prettyprint_status_register_atmel_at25_wpen(uint8_t status)
+{
+	msg_cdbg("Chip status register: Write Protect Enable (WPEN) is %sset\n",
+		 (status & (1 << 7)) ? "" : "not ");
+}
+
+static void spi_prettyprint_status_register_atmel_at25_srpl(uint8_t status)
+{
+	msg_cdbg("Chip status register: Sector Protection Register Lock (SRPL) is %sset\n",
+		 (status & (1 << 7)) ? "" : "not ");
+}
+
+static void spi_prettyprint_status_register_atmel_at25_epewpp(uint8_t status)
+{
+	msg_cdbg("Chip status register: Erase/Program Error (EPE) is %sset\n",
+		 (status & (1 << 5)) ? "" : "not ");
+	msg_cdbg("Chip status register: WP# pin (WPP) is %sasserted\n",
+		 (status & (1 << 4)) ? "not " : "");
+}
+
+static void spi_prettyprint_status_register_atmel_at25_swp(uint8_t status)
+{
+	msg_cdbg("Chip status register: Software Protection Status (SWP): ");
+	switch (status & (3 << 2)) {
+	case 0x0 << 2:
+		msg_cdbg("no sectors are protected\n");
+		break;
+	case 0x1 << 2:
+		msg_cdbg("some sectors are protected\n");
+		/* FIXME: Read individual Sector Protection Registers. */
+		break;
+	case 0x3 << 2:
+		msg_cdbg("all sectors are protected\n");
+		break;
+	default:
+		msg_cdbg("reserved for future use\n");
+		break;
+	}
+}
+
+int spi_prettyprint_status_register_at25df(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_atmel_at25_srpl(status);
+	spi_prettyprint_status_register_bit(status, 6);
+	spi_prettyprint_status_register_atmel_at25_epewpp(status);
+	spi_prettyprint_status_register_atmel_at25_swp(status);
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+int spi_prettyprint_status_register_at25df_sec(struct flashctx *flash)
+{
+	/* FIXME: We should check the security lockdown. */
+	msg_cdbg("Ignoring security lockdown (if present)\n");
+	msg_cdbg("Ignoring status register byte 2\n");
+	return spi_prettyprint_status_register_at25df(flash);
+}
+
+int spi_prettyprint_status_register_at25f512b(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_atmel_at25_srpl(status);
+	spi_prettyprint_status_register_bit(status, 6);
+	spi_prettyprint_status_register_atmel_at25_epewpp(status);
+	spi_prettyprint_status_register_bit(status, 3);
+	spi_prettyprint_status_register_bp(status, 0);
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+int spi_prettyprint_status_register_at25fs010(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_atmel_at25_wpen(status);
+	msg_cdbg("Chip status register: Bit 6 / Block Protect 4 (BP4) is "
+		 "%sset\n", (status & (1 << 6)) ? "" : "not ");
+	msg_cdbg("Chip status register: Bit 5 / Block Protect 3 (BP3) is "
+		 "%sset\n", (status & (1 << 5)) ? "" : "not ");
+	spi_prettyprint_status_register_bit(status, 4);
+	msg_cdbg("Chip status register: Bit 3 / Block Protect 1 (BP1) is "
+		 "%sset\n", (status & (1 << 3)) ? "" : "not ");
+	msg_cdbg("Chip status register: Bit 2 / Block Protect 0 (BP0) is "
+		 "%sset\n", (status & (1 << 2)) ? "" : "not ");
+	/* FIXME: Pretty-print detailed sector protection status. */
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+int spi_prettyprint_status_register_at25fs040(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_atmel_at25_wpen(status);
+	spi_prettyprint_status_register_bp(status, 4);
+	/* FIXME: Pretty-print detailed sector protection status. */
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+int spi_prettyprint_status_register_at26df081a(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_atmel_at25_srpl(status);
+	msg_cdbg("Chip status register: Sequential Program Mode Status (SPM) is %sset\n",
+		 (status & (1 << 6)) ? "" : "not ");
+	spi_prettyprint_status_register_atmel_at25_epewpp(status);
+	spi_prettyprint_status_register_atmel_at25_swp(status);
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+int spi_disable_blockprotect_at25df(struct flashctx *flash)
+{
+	uint8_t status;
+	int result;
+
+	status = spi_read_status_register(flash);
+	/* If block protection is disabled, stop here. */
+	if ((status & (3 << 2)) == 0)
+		return 0;
+
+	msg_cdbg("Some block protection in effect, disabling... ");
+	if (status & (1 << 7)) {
+		msg_cdbg("Need to disable Sector Protection Register Lock\n");
+		if ((status & (1 << 4)) == 0) {
+			msg_cerr("WP# pin is active, disabling "
+				 "write protection is impossible.\n");
+			return 1;
+		}
+		/* All bits except bit 7 (SPRL) are readonly. */
+		result = spi_write_status_register(flash, status & ~(1 << 7));
+		if (result) {
+			msg_cerr("spi_write_status_register failed.\n");
+			return result;
+		}
+		
+	}
+	/* Global unprotect. Make sure to mask SPRL as well. */
+	result = spi_write_status_register(flash, status & ~0xbc);
+	if (result) {
+		msg_cerr("spi_write_status_register failed.\n");
+		return result;
+	}
+	status = spi_read_status_register(flash);
+	if ((status & (3 << 2)) != 0) {
+		msg_cerr("Block protection could not be disabled!\n");
+		return 1;
+	}
+	msg_cdbg("done.\n");
+	return 0;
+}
+
+int spi_disable_blockprotect_at25df_sec(struct flashctx *flash)
+{
+	/* FIXME: We should check the security lockdown. */
+	msg_cinfo("Ignoring security lockdown (if present)\n");
+	return spi_disable_blockprotect_at25df(flash);
+}
+
+int spi_disable_blockprotect_at25f512b(struct flashctx *flash)
+{
+	/* spi_disable_blockprotect_at25df is not really the right way to do
+	 * this, but the side effects of said function work here as well.
+	 */
+	return spi_disable_blockprotect_at25df(flash);
+}
+
+int spi_disable_blockprotect_at25fs010(struct flashctx *flash)
+{
+	uint8_t status;
+	int result;
+
+	status = spi_read_status_register(flash);
+	/* If block protection is disabled, stop here. */
+	if ((status & 0x6c) == 0)
+		return 0;
+
+	msg_cdbg("Some block protection in effect, disabling... ");
+	if (status & (1 << 7)) {
+		msg_cdbg("Need to disable Status Register Write Protect\n");
+		/* Clear bit 7 (WPEN). */
+		result = spi_write_status_register(flash, status & ~(1 << 7));
+		if (result) {
+			msg_cerr("spi_write_status_register failed.\n");
+			return result;
+		}
+	}
+	/* Global unprotect. Make sure to mask WPEN as well. */
+	result = spi_write_status_register(flash, status & ~0xec);
+	if (result) {
+		msg_cerr("spi_write_status_register failed.\n");
+		return result;
+	}
+	status = spi_read_status_register(flash);
+	if ((status & 0x6c) != 0) {
+		msg_cerr("Block protection could not be disabled!\n");
+		return 1;
+	}
+	msg_cdbg("done.\n");
+	return 0;
+}
+
+int spi_disable_blockprotect_at25fs040(struct flashctx *flash)
+{
+	uint8_t status;
+	int result;
+
+	status = spi_read_status_register(flash);
+	/* If block protection is disabled, stop here. */
+	if ((status & 0x7c) == 0)
+		return 0;
+
+	msg_cdbg("Some block protection in effect, disabling... ");
+	if (status & (1 << 7)) {
+		msg_cdbg("Need to disable Status Register Write Protect\n");
+		/* Clear bit 7 (WPEN). */
+		result = spi_write_status_register(flash, status & ~(1 << 7));
+		if (result) {
+			msg_cerr("spi_write_status_register failed.\n");
+			return result;
+		}
+	}
+	/* Global unprotect. Make sure to mask WPEN as well. */
+	result = spi_write_status_register(flash, status & ~0xfc);
+	if (result) {
+		msg_cerr("spi_write_status_register failed.\n");
+		return result;
+	}
+	status = spi_read_status_register(flash);
+	if ((status & 0x7c) != 0) {
+		msg_cerr("Block protection could not be disabled!\n");
+		return 1;
+	}
+	msg_cdbg("done.\n");
+	return 0;
+}
+
+/* === SST === */
+
+static void spi_prettyprint_status_register_sst25_common(uint8_t status)
+{
+	spi_prettyprint_status_register_hex(status);
+
+	spi_prettyprint_status_register_bpl(status);
+	msg_cdbg("Chip status register: Auto Address Increment Programming (AAI) is %sset\n",
+		 (status & (1 << 6)) ? "" : "not ");
+	spi_prettyprint_status_register_bp(status, 3);
+	spi_prettyprint_status_register_welwip(status);
+}
+
+int spi_prettyprint_status_register_sst25(struct flashctx *flash)
+{
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_sst25_common(status);
+	return 0;
+}
+
+int spi_prettyprint_status_register_sst25vf016(struct flashctx *flash)
+{
+	static const char *const bpt[] = {
+		"none",
+		"1F0000H-1FFFFFH",
+		"1E0000H-1FFFFFH",
+		"1C0000H-1FFFFFH",
+		"180000H-1FFFFFH",
+		"100000H-1FFFFFH",
+		"all", "all"
+	};
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_sst25_common(status);
+	msg_cdbg("Resulting block protection : %s\n", bpt[(status & 0x1c) >> 2]);
+	return 0;
+}
+
+int spi_prettyprint_status_register_sst25vf040b(struct flashctx *flash)
+{
+	static const char *const bpt[] = {
+		"none",
+		"0x70000-0x7ffff",
+		"0x60000-0x7ffff",
+		"0x40000-0x7ffff",
+		"all blocks", "all blocks", "all blocks", "all blocks"
+	};
+	uint8_t status = spi_read_status_register(flash);
+	spi_prettyprint_status_register_sst25_common(status);
+	msg_cdbg("Resulting block protection : %s\n", bpt[(status & 0x1c) >> 2]);
+	return 0;
+}