4BA: Basic support for 4-bytes addressing mode extensions

If flash chip is switched to 4-bytes addressing mode then all
read/erase/program instructions will be switched from 3-bytes mode
to 4-bytes mode. Then well known instructions like 03h (Read),
02h (Program) and 20h,52h,D8h (Erase) will become one byte longer
and accept 4-bytes address instead of 3-bytes.

This patch provides support for well known instructions in 4-bytes
addressing mode. Also here is the code to enter 4-bytes addressing
mode by execute the instruction B7h (Enter 4-bytes mode).

Patched files
-------------
chipdrivers.h
+ added functions declarations for spi4ba.c

flash.h
+ feature definitions added

Makefile
+ added spi4ba.c

Added files
-----------
spi4ba.h
+ definitions for 4-bytes addressing JEDEC commands
+ functions declarations from spi4ba.c (same as in chipdrivers.h, just to see)

spi4ba.c
+ functions for enter 4-bytes addressing mode
+ functions for read/write/erase in 4-bytes addressing mode

Change-Id: Ie72e2a89cd75fb4d09f48e81c4c1d927c317b7a7
Signed-off-by: Boris Baykov <dev@borisbaykov.com>, Russia, Jan 2014
[clg: ported from
      https://www.flashrom.org/pipermail/flashrom/2015-January/013199.html ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-on: https://review.coreboot.org/20513
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/chipdrivers.h b/chipdrivers.h
index c85eac9..dccd1ff 100644
--- a/chipdrivers.h
+++ b/chipdrivers.h
@@ -195,4 +195,14 @@
 int probe_en29lv640b(struct flashctx *flash);
 int write_en29lv640b(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len);
 
+/* spi4ba.c */
+int spi_enter_4ba_b7(struct flashctx *flash);
+int spi_enter_4ba_b7_we(struct flashctx *flash);
+int spi_byte_program_4ba(struct flashctx *flash, unsigned int addr, uint8_t databyte);
+int spi_nbyte_program_4ba(struct flashctx *flash, unsigned int addr, const uint8_t *bytes, unsigned int len);
+int spi_nbyte_read_4ba(struct flashctx *flash, unsigned int addr, uint8_t *bytes, unsigned int len);
+int spi_block_erase_20_4ba(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
+int spi_block_erase_52_4ba(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
+int spi_block_erase_d8_4ba(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
+
 #endif /* !__CHIPDRIVERS_H__ */