Add support for AT45CS1282

This one is even more strange than the AT45DB chips. Like the AT45DB321C
it does not support any power-of-2 page sizes. There is only one asymmetrical
eraser and that uses two opcodes.

Corresponding to flashrom svn r1725.
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>

at45db.c

@@ -419,6 +419,47 @@ int spi_erase_at45db_chip(struct flashctx *flash, unsigned int addr, unsigned in
 	return at45db_erase(flash, AT45DB_CHIP_ERASE, AT45DB_CHIP_ERASE_ADDR, 500000, 200);
 }
 
+/* This one is really special and works only for AT45CS1282. It uses two different opcodes depending on the
+ * address and has an asymmetric layout. */
+int spi_erase_at45cs_sector(struct flashctx *flash, unsigned int addr, unsigned int blocklen)
+{
+	const unsigned int page_size = flash->chip->page_size;
+	const unsigned int total_size = flash->chip->total_size * 1024;
+	const struct block_eraser be = flash->chip->block_erasers[0];
+	const unsigned int sec_0a_top = be.eraseblocks[0].size;
+	const unsigned int sec_0b_top = be.eraseblocks[0].size + be.eraseblocks[1].size;
+
+	if ((addr + blocklen) > total_size) {
+		msg_cerr("%s: tried to erase a sector beyond flash boundary: addr=%u, blocklen=%u, size=%u\n",
+			 __func__, addr, blocklen, total_size);
+		return 1;
+	}
+
+	bool partial_range = false;
+	uint8_t opcode = 0x7C; /* Used for all but sector 0a. */
+	if (addr < sec_0a_top) {
+		opcode = 0x50;
+		/* One single sector of 8 pages at address 0. */
+		if (addr != 0 || blocklen != (8 * page_size))
+			partial_range = true;
+	} else if (addr < sec_0b_top) {
+		/* One single sector of 248 pages adjacent to the first. */
+		if (addr != sec_0a_top || blocklen != (248 * page_size))
+			partial_range = true;
+	} else {
+		/* The rest is filled by 63 aligned sectors of 256 pages. */
+		if ((addr % (256 * page_size)) != 0 || (blocklen % (256 * page_size)) != 0)
+			partial_range = true;
+	}
+	if (partial_range) {
+		msg_cerr("%s: cannot erase partial sectors: addr=%u, blocklen=%u\n", __func__, addr, blocklen);
+		return 1;
+	}
+
+	/* Needs up to 4 s for completion, so let's wait 20 seconds in 200 ms steps. */
+	return at45db_erase(flash, opcode, at45db_convert_addr(addr, page_size), 200000, 100);
+}
+
 static int at45db_fill_buffer1(struct flashctx *flash, uint8_t *bytes, unsigned int off, unsigned int len)
 {
 	const unsigned int page_size = flash->chip->page_size;

chipdrivers.h

@@ -121,6 +121,7 @@ int spi_erase_at45db_page(struct flashctx *flash, unsigned int addr, unsigned in
 int spi_erase_at45db_block(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
 int spi_erase_at45db_sector(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
 int spi_erase_at45db_chip(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
+int spi_erase_at45cs_sector(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
 
 /* 82802ab.c */
 uint8_t wait_82802ab(struct flashctx *flash);

flashchips.c

@@ -2323,11 +2323,26 @@ const struct flashchip flashchips[] = {
 		.total_size	= 16896 /* No power of two sizes */,
 		.page_size	= 1056 /* No power of two sizes */,
 		/* does not support EWSR nor WREN and has no writable status register bits whatsoever */
-		.tested		= TEST_BAD_REW,
+		/* OTP: 128B total, 64B pre-programmed; read 0x77 (4 dummy bytes); write 0x9A (via buffer) */
+		.feature_bits	= FEATURE_OTP,
+		.tested		= TEST_UNTESTED,
 		.probe		= probe_spi_rdid,
 		.probe_timing	= TIMING_ZERO,
-		.write		= NULL /* Incompatible Page write */,
-		.read		= NULL /* Incompatible read */,
+		.block_erasers	=
+		{
+			{
+				.eraseblocks = {
+					{8 * 1056, 1},    /* sector 0a:      opcode 50h */
+					{248 * 1056, 1},  /* sector 0b:      opcode 7Ch */
+					{256 * 1056, 63}, /* sectors 1 - 63: opcode 7Ch */
+				},
+				.block_erase = spi_erase_at45cs_sector,
+			}
+		},
+		.printlock	= spi_prettyprint_status_register_plain,
+		.gran		= write_gran_1056bytes,
+		.write		= spi_write_at45db,
+		.read		= spi_read_at45db,
 		.voltage	= {2700, 3600},
 	},