Add detailed status register printing and unlocking for all ATMEL AT25* chips

Add support for Atmel AT25DF081A and AT25DQ161.

Some chips require EWSR before WRSR, others require WREN before WRSR,
and some support both variants. Add feature_bits to select the correct
SPI command, and default to EWSR.

Corresponding to flashrom svn r1115.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Tested-by: Steven Rosario
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>

7 files changed, 442 insertions, 29 deletions

diff --git a/chipdrivers.h b/chipdrivers.h
index 9e7af2dc7..119ea7002 100644
--- a/chipdrivers.h
+++ b/chipdrivers.h
@@ -47,7 +47,17 @@ int spi_chip_write_1_new(struct flashchip *flash, uint8_t *buf, int start, int l
 int spi_chip_write_256_new(struct flashchip *flash, uint8_t *buf, int start, int len);
 int spi_chip_read(struct flashchip *flash, uint8_t *buf, int start, int len);
 uint8_t spi_read_status_register(void);
+int spi_prettyprint_status_register_at25df(struct flashchip *flash);
+int spi_prettyprint_status_register_at25df_sec(struct flashchip *flash);
+int spi_prettyprint_status_register_at25f(struct flashchip *flash);
+int spi_prettyprint_status_register_at25fs010(struct flashchip *flash);
+int spi_prettyprint_status_register_at25fs040(struct flashchip *flash);
 int spi_disable_blockprotect(struct flashchip *flash);
+int spi_disable_blockprotect_at25df(struct flashchip *flash);
+int spi_disable_blockprotect_at25df_sec(struct flashchip *flash);
+int spi_disable_blockprotect_at25f(struct flashchip *flash);
+int spi_disable_blockprotect_at25fs010(struct flashchip *flash);
+int spi_disable_blockprotect_at25fs040(struct flashchip *flash);
 int spi_byte_program(int addr, uint8_t databyte);
 int spi_nbyte_program(int addr, uint8_t *bytes, int len);
 int spi_nbyte_read(int addr, uint8_t *bytes, int len);
diff --git a/flash.h b/flash.h
index ff84602fc..6f0d7c067 100644
--- a/flash.h
+++ b/flash.h
@@ -69,8 +69,9 @@ enum chipbustype {
 
 /*
  * How many different erase functions do we have per chip?
+ * Atmel AT25FS010 has 6 different functions.
  */
-#define NUM_ERASEFUNCTIONS 5
+#define NUM_ERASEFUNCTIONS 6
 
 #define FEATURE_REGISTERMAP	(1 << 0)
 #define FEATURE_BYTEWRITES	(1 << 1)
@@ -82,6 +83,9 @@ enum chipbustype {
 #define FEATURE_ADDR_2AA	(1 << 2)
 #define FEATURE_ADDR_AAA	(2 << 2)
 #define FEATURE_ADDR_SHIFTED	(1 << 5)
+#define FEATURE_WRSR_EWSR	(1 << 6)
+#define FEATURE_WRSR_WREN	(1 << 7)
+#define FEATURE_WRSR_EITHER	(FEATURE_WRSR_EWSR | FEATURE_WRSR_WREN)
 
 struct flashchip {
 	const char *vendor;
diff --git a/flashchips.c b/flashchips.c
index 576794891..c60a7fb4e 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -789,6 +789,7 @@ struct flashchip flashchips[] = {
 		.model_id	= AT_25DF021,
 		.total_size	= 256,
 		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
@@ -811,7 +812,8 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25df,
+		.unlock		= spi_disable_blockprotect_at25df,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -824,6 +826,7 @@ struct flashchip flashchips[] = {
 		.model_id	= AT_25DF041A,
 		.total_size	= 512,
 		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
@@ -846,7 +849,8 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25df,
+		.unlock		= spi_disable_blockprotect_at25df,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -859,6 +863,7 @@ struct flashchip flashchips[] = {
 		.model_id	= AT_25DF081,
 		.total_size	= 1024,
 		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
@@ -881,7 +886,45 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25df,
+		.unlock		= spi_disable_blockprotect_at25df,
+		.write		= spi_chip_write_256,
+		.read		= spi_chip_read,
+	},
+
+	{
+		.vendor		= "Atmel",
+		.name		= "AT25DF081A",
+		.bustype	= CHIP_BUSTYPE_SPI,
+		.manufacture_id	= ATMEL_ID,
+		.model_id	= AT_25DF081A,
+		.total_size	= 1024,
+		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
+		.tested		= TEST_UNTESTED,
+		.probe		= probe_spi_rdid,
+		.probe_timing	= TIMING_ZERO,
+		.block_erasers	=
+		{
+			{
+				.eraseblocks = { {4 * 1024, 256} },
+				.block_erase = spi_block_erase_20,
+			}, {
+				.eraseblocks = { {32 * 1024, 32} },
+				.block_erase = spi_block_erase_52,
+			}, {
+				.eraseblocks = { {64 * 1024, 16} },
+				.block_erase = spi_block_erase_d8,
+			}, {
+				.eraseblocks = { {1024 * 1024, 1} },
+				.block_erase = spi_block_erase_60,
+			}, {
+				.eraseblocks = { {1024 * 1024, 1} },
+				.block_erase = spi_block_erase_c7,
+			}
+		},
+		.printlock	= spi_prettyprint_status_register_at25df_sec,
+		.unlock		= spi_disable_blockprotect_at25df_sec,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -894,6 +937,7 @@ struct flashchip flashchips[] = {
 		.model_id	= AT_25DF161,
 		.total_size	= 2048,
 		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
@@ -916,7 +960,8 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25df_sec,
+		.unlock		= spi_disable_blockprotect_at25df_sec,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -929,6 +974,7 @@ struct flashchip flashchips[] = {
 		.model_id	= AT_25DF321,
 		.total_size	= 4096,
 		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
 		.tested		= TEST_OK_PRW,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
@@ -951,7 +997,8 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25df,
+		.unlock		= spi_disable_blockprotect_at25df,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -964,6 +1011,7 @@ struct flashchip flashchips[] = {
 		.model_id	= AT_25DF321A,
 		.total_size	= 4096,
 		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
@@ -986,7 +1034,8 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25df_sec,
+		.unlock		= spi_disable_blockprotect_at25df_sec,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -999,6 +1048,7 @@ struct flashchip flashchips[] = {
 		.model_id	= AT_25DF641,
 		.total_size	= 8192,
 		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
@@ -1021,7 +1071,45 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25df_sec,
+		.unlock		= spi_disable_blockprotect_at25df_sec,
+		.write		= spi_chip_write_256,
+		.read		= spi_chip_read,
+	},
+
+	{
+		.vendor		= "Atmel",
+		.name		= "AT25DQ161",
+		.bustype	= CHIP_BUSTYPE_SPI,
+		.manufacture_id	= ATMEL_ID,
+		.model_id	= AT_25DQ161,
+		.total_size	= 2048,
+		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
+		.tested		= TEST_UNTESTED,
+		.probe		= probe_spi_rdid,
+		.probe_timing	= TIMING_ZERO,
+		.block_erasers	=
+		{
+			{
+				.eraseblocks = { {4 * 1024, 512} },
+				.block_erase = spi_block_erase_20,
+			}, {
+				.eraseblocks = { {32 * 1024, 64} },
+				.block_erase = spi_block_erase_52,
+			}, {
+				.eraseblocks = { {64 * 1024, 32} },
+				.block_erase = spi_block_erase_d8,
+			}, {
+				.eraseblocks = { {2 * 1024 * 1024, 1} },
+				.block_erase = spi_block_erase_60,
+			}, {
+				.eraseblocks = { {2 * 1024 * 1024, 1} },
+				.block_erase = spi_block_erase_c7,
+			}
+		},
+		.printlock	= spi_prettyprint_status_register_at25df_sec,
+		.unlock		= spi_disable_blockprotect_at25df_sec,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -1034,6 +1122,7 @@ struct flashchip flashchips[] = {
 		.model_id	= AT_25F512B,
 		.total_size	= 64,
 		.page_size	= 256,
+		.feature_bits	= FEATURE_WRSR_WREN,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
@@ -1056,7 +1145,8 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25f,
+		.unlock		= spi_disable_blockprotect_at25f,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -1078,6 +1168,9 @@ struct flashchip flashchips[] = {
 				.eraseblocks = { {4 * 1024, 32} },
 				.block_erase = spi_block_erase_20,
 			}, {
+				.eraseblocks = { {4 * 1024, 32} },
+				.block_erase = spi_block_erase_d7,
+			}, {
 				.eraseblocks = { {32 * 1024, 4} },
 				.block_erase = spi_block_erase_52,
 			}, {
@@ -1091,7 +1184,8 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25fs010,
+		.unlock		= spi_disable_blockprotect_at25fs010,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
@@ -1126,7 +1220,8 @@ struct flashchip flashchips[] = {
 				.block_erase = spi_block_erase_c7,
 			}
 		},
-		.unlock		= spi_disable_blockprotect,
+		.printlock	= spi_prettyprint_status_register_at25fs040,
+		.unlock		= spi_disable_blockprotect_at25fs040,
 		.write		= spi_chip_write_256,
 		.read		= spi_chip_read,
 	},
diff --git a/flashchips.h b/flashchips.h
index 3e2befa60..1f1c96853 100644
--- a/flashchips.h
+++ b/flashchips.h
@@ -110,12 +110,19 @@
 #define AT_25DF021		0x4300
 #define AT_25DF041A		0x4401
 #define AT_25DF081		0x4502
+#define AT_25DF081A		0x4501	/* Yes, 81A has a lower number than 81 */
 #define AT_25DF161		0x4602
 #define AT_25DF321		0x4700	/* Same as 26DF321 */
 #define AT_25DF321A		0x4701
 #define AT_25DF641		0x4800
-#define AT_25F512A		0x65 /* Needs special RDID. AT25F512A_RDID 15 1d */
+#define AT_25DQ161		0x8600
+#define AT25F512		/* No device ID found in datasheet. Vendor ID
+				 * can be read with AT25F512A_RDID */
+#define AT_25F512A		0x65 /* Needs AT25F512A_RDID */
 #define AT_25F512B		0x6500
+#define AT25F1024		/* No device ID found in datasheet. Vendor ID
+				 * can be read with AT25F512A_RDID */
+#define AT_25F1024A		0x60 /* Needs AT25F512A_RDID */
 #define AT_25FS010		0x6601
 #define AT_25FS040		0x6604
 #define AT_26DF041		0x4400
diff --git a/spi.c b/spi.c
index b005cdc40..ebacd6072 100644
--- a/spi.c
+++ b/spi.c
@@ -30,8 +30,6 @@
 
 enum spi_controller spi_controller = SPI_CONTROLLER_NONE;
 
-void spi_prettyprint_status_register(struct flashchip *flash);
-
 const struct spi_programmer spi_programmer[] = {
 	{ /* SPI_CONTROLLER_NONE */
 		.command = NULL,
diff --git a/spi.h b/spi.h
index 383e53559..edf303ee4 100644
--- a/spi.h
+++ b/spi.h
@@ -31,7 +31,7 @@
 #define JEDEC_RDID_INSIZE	0x03
 
 /* AT25F512A has bit 3 as don't care bit in commands */
-#define AT25F512A_RDID		0x15
+#define AT25F512A_RDID		0x15	/* 0x15 or 0x1d */
 #define AT25F512A_RDID_OUTSIZE	0x01
 #define AT25F512A_RDID_INSIZE	0x02
 
@@ -123,5 +123,6 @@
 #define SPI_INVALID_OPCODE	-2
 #define SPI_INVALID_ADDRESS	-3
 #define SPI_INVALID_LENGTH	-4
+#define SPI_FLASHROM_BUG	-5
 
 #endif		/* !__SPI_H__ */
diff --git a/spi25.c b/spi25.c
index 562effaf8..16d162a02 100644
--- a/spi25.c
+++ b/spi25.c
@@ -312,7 +312,16 @@ uint8_t spi_read_status_register(void)
 }
 
 /* Prettyprint the status register. Common definitions. */
-void spi_prettyprint_status_register_common(uint8_t status)
+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 ");
+}
+
+/* Prettyprint the status register. Common definitions. */
+static void spi_prettyprint_status_register_common(uint8_t status)
 {
 	msg_cdbg("Chip status register: Bit 5 / Block Protect 3 (BP3) is "
 		     "%sset\n", (status & (1 << 5)) ? "" : "not ");
@@ -322,10 +331,7 @@ void spi_prettyprint_status_register_common(uint8_t status)
 		     "%sset\n", (status & (1 << 3)) ? "" : "not ");
 	msg_cdbg("Chip status register: Bit 2 / Block Protect 0 (BP0) is "
 		     "%sset\n", (status & (1 << 2)) ? "" : "not ");
-	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 ");
+	spi_prettyprint_status_register_welwip(status);
 }
 
 /* Prettyprint the status register. Works for
@@ -338,6 +344,121 @@ void spi_prettyprint_status_register_amic_a25l(uint8_t status)
 	spi_prettyprint_status_register_common(status);
 }
 
+/* Prettyprint the status register. Common definitions. */
+static void spi_prettyprint_status_register_at25_srplepewpp(uint8_t status)
+{
+	msg_cdbg("Chip status register: Sector Protection Register Lock (SRPL) "
+		 "is %sset\n", (status & (1 << 7)) ? "" : "not ");
+	msg_cdbg("Chip status register: Bit 6 "
+		 "is %sset\n", (status & (1 << 6)) ? "" : "not ");
+	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 %sactive\n", (status & (1 << 4)) ? "not " : "");
+}
+
+int spi_prettyprint_status_register_at25df(struct flashchip *flash)
+{
+	uint8_t status;
+
+	status = spi_read_status_register();
+	msg_cdbg("Chip status register is %02x\n", status);
+
+	spi_prettyprint_status_register_at25_srplepewpp(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;
+	}
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+int spi_prettyprint_status_register_at25df_sec(struct flashchip *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_at25f(struct flashchip *flash)
+{
+	uint8_t status;
+
+	status = spi_read_status_register();
+	msg_cdbg("Chip status register is %02x\n", status);
+
+	spi_prettyprint_status_register_at25_srplepewpp(status);
+	msg_cdbg("Chip status register: Bit 3 "
+		 "is %sset\n", (status & (1 << 3)) ? "" : "not ");
+	msg_cdbg("Chip status register: Block Protect 0 (BP0) is "
+		 "%sset, %s sectors are protected\n",
+		 (status & (1 << 2)) ? "" : "not ",
+		 (status & (1 << 2)) ? "all" : "no");
+	spi_prettyprint_status_register_welwip(status);
+	return 0;
+}
+
+int spi_prettyprint_status_register_at25fs010(struct flashchip *flash)
+{
+	uint8_t status;
+
+	status = spi_read_status_register();
+	msg_cdbg("Chip status register is %02x\n", status);
+
+	msg_cdbg("Chip status register: Status Register Write Protect (WPEN) "
+		 "is %sset\n", (status & (1 << 7)) ? "" : "not ");
+	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 ");
+	msg_cdbg("Chip status register: Bit 4 is "
+		 "%sset\n", (status & (1 << 4)) ? "" : "not ");
+	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 flashchip *flash)
+{
+	uint8_t status;
+
+	status = spi_read_status_register();
+	msg_cdbg("Chip status register is %02x\n", status);
+
+	msg_cdbg("Chip status register: Status Register Write Protect (WPEN) "
+		 "is %sset\n", (status & (1 << 7)) ? "" : "not ");
+	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 ");
+	msg_cdbg("Chip status register: Bit 4 / Block Protect 2 (BP2) is "
+		 "%sset\n", (status & (1 << 4)) ? "" : "not ");
+	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;
+}
+
 /* Prettyprint the status register. Works for
  * ST M25P series
  * MX MX25L series
@@ -732,12 +853,12 @@ int spi_write_status_enable(void)
  * This is according the SST25VF016 datasheet, who knows it is more
  * generic that this...
  */
-int spi_write_status_register(int status)
+static int spi_write_status_register_ewsr(struct flashchip *flash, int status)
 {
 	int result;
 	struct spi_command cmds[] = {
 	{
-	/* FIXME: WRSR requires either EWSR or WREN depending on chip type. */
+	/* WRSR requires either EWSR or WREN depending on chip type. */
 		.writecnt	= JEDEC_EWSR_OUTSIZE,
 		.writearr	= (const unsigned char[]){ JEDEC_EWSR },
 		.readcnt	= 0,
@@ -759,9 +880,59 @@ int spi_write_status_register(int status)
 		msg_cerr("%s failed during command execution\n",
 			__func__);
 	}
+	/* WRSR performs a self-timed erase before the changes take effect. */
+	programmer_delay(100 * 1000);
+	return result;
+}
+
+static int spi_write_status_register_wren(struct flashchip *flash, int status)
+{
+	int result;
+	struct spi_command cmds[] = {
+	{
+	/* WRSR requires either EWSR or WREN depending on chip type. */
+		.writecnt	= JEDEC_WREN_OUTSIZE,
+		.writearr	= (const unsigned char[]){ JEDEC_WREN },
+		.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(cmds);
+	if (result) {
+		msg_cerr("%s failed during command execution\n",
+			__func__);
+	}
+	/* WRSR performs a self-timed erase before the changes take effect. */
+	programmer_delay(100 * 1000);
 	return result;
 }
 
+static int spi_write_status_register(struct flashchip *flash, int status)
+{
+	int ret = 1;
+
+	if (!(flash->feature_bits & (FEATURE_WRSR_WREN | FEATURE_WRSR_EWSR))) {
+		msg_cdbg("Missing status register write definition, assuming "
+			 "EWSR is needed\n");
+		flash->feature_bits |= FEATURE_WRSR_EWSR;
+	}
+	if (flash->feature_bits & FEATURE_WRSR_WREN)
+		ret = spi_write_status_register_wren(flash, status);
+	if (ret && (flash->feature_bits & FEATURE_WRSR_EWSR))
+		ret = spi_write_status_register_ewsr(flash, status);
+	return ret;
+}
+
 int spi_byte_program(int addr, uint8_t databyte)
 {
 	int result;
@@ -844,26 +1015,153 @@ int spi_nbyte_program(int addr, uint8_t *bytes, int len)
 	return result;
 }
 
+/* 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 flashchip *flash)
 {
 	uint8_t status;
 	int result;
 
 	status = spi_read_status_register();
-	/* If there is block protection in effect, unprotect it first. */
+	/* If block protection is disabled, stop here. */
+	if ((status & 0x3c) == 0)
+		return 0;
+
+	msg_cdbg("Some block protection in effect, disabling\n");
+	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();
 	if ((status & 0x3c) != 0) {
-		msg_cdbg("Some block protection in effect, disabling\n");
-		result = spi_write_status_register(status & ~0x3c);
+		msg_cerr("Block protection could not be disabled!\n");
+		return 1;
+	}
+	return 0;
+}
+
+int spi_disable_blockprotect_at25df(struct flashchip *flash)
+{
+	uint8_t status;
+	int result;
+
+	status = spi_read_status_register();
+	/* If block protection is disabled, stop here. */
+	if ((status & (3 << 2)) == 0)
+		return 0;
+
+	msg_cdbg("Some block protection in effect, disabling\n");
+	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;
 		}
-		status = spi_read_status_register();
-		if ((status & 0x3c) != 0) {
-			msg_cerr("Block protection could not be disabled!\n");
-			return 1;
+		
+	}
+	/* 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();
+	if ((status & (3 << 2)) != 0) {
+		msg_cerr("Block protection could not be disabled!\n");
+		return 1;
+	}
+	return 0;
+}
+
+int spi_disable_blockprotect_at25df_sec(struct flashchip *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_at25f(struct flashchip *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 flashchip *flash)
+{
+	uint8_t status;
+	int result;
+
+	status = spi_read_status_register();
+	/* If block protection is disabled, stop here. */
+	if ((status & 0x6c) == 0)
+		return 0;
+
+	msg_cdbg("Some block protection in effect, disabling\n");
+	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();
+	if ((status & 0x6c) != 0) {
+		msg_cerr("Block protection could not be disabled!\n");
+		return 1;
+	}
+	return 0;
+}
+int spi_disable_blockprotect_at25fs040(struct flashchip *flash)
+{
+	uint8_t status;
+	int result;
+
+	status = spi_read_status_register();
+	/* If block protection is disabled, stop here. */
+	if ((status & 0x7c) == 0)
+		return 0;
+
+	msg_cdbg("Some block protection in effect, disabling\n");
+	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();
+	if ((status & 0x7c) != 0) {
+		msg_cerr("Block protection could not be disabled!\n");
+		return 1;
+	}
 	return 0;
 }