4BA: Support for new direct-4BA instructions + W25Q256.V update

Large flash chips usually support special instructions to work with
4-bytes address directly from 3-bytes addressing mode and without
do switching to 4-bytes mode. There are 13h (4BA Read), 12h (4BA Program)
and 21h,5Ch,DCh (4BA Erase), correspondingly. However not all these
instructions are supported by all large flash chips. Some chips
support 13h only, some 13h,12h,21h and DCh, but not 5Ch. This depends
on the manufacturer of the chip.

This patch provides code to use direct 4-bytes addressing instructions.

This code should work but it tested partially only. My W25Q256FV has
support for 4BA_Read (13h), but doesn't have support 4BA_Program (12h)
and 4BA_Erase instructions. So, direct 4BA program and erase
should be tested after.

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

flash.h
+ feature definitions added

flashchips.c
+ modified definition of Winbond W25Q256BV/W25Q256FV chips

flashrom.c
+ modified switch to 4-bytes addressing for direct-4BA instructions

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 read/write/erase directly with 4-bytes address (from any mode)

Change-Id: Ib51bcc5de7826b30ad697fcbb9a5152bde2c2ac9
Signed-off-by: Boris Baykov <dev@borisbaykov.com>, Russia, Jan 2014
[clg: ported from
      https://www.flashrom.org/pipermail/flashrom/2015-January/013198.html ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-on: https://review.coreboot.org/20508
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/flashrom.c b/flashrom.c
index 3adc3c00e..8569a4960 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -2233,8 +2233,14 @@ int prepare_flash_access(struct flashctx *const flash,
 		else if(flash->chip->feature_bits & FEATURE_4BA_EXTENDED_ADDR_REG) {
 			msg_cdbg("Using 4-bytes addressing with extended address register.\n");
 		}
-		/* Go to 4-Bytes Addressing mode */
-		else {
+		/* Go to 4-Bytes Addressing mode if selected
+		   operation requires 4-Bytes Addressing mode
+		   (no need if functions are direct-4BA) */
+		else if(((read_it || verify_it)
+			&& (!(flash->chip->feature_bits & FEATURE_4BA_DIRECT_READ)))
+		   || ((erase_it || write_it)
+			&& ((flash->chip->feature_bits & FEATURE_4BA_ALL_DIRECT) != FEATURE_4BA_ALL_DIRECT))) {
+
 			if (!flash->chip->four_bytes_addr_funcs.enter_4ba) {
 				msg_cerr("No function for Enter 4-bytes addressing mode for this flash chip.\n"
 					"Please report to flashrom@flashrom.org\n");
@@ -2248,6 +2254,11 @@ int prepare_flash_access(struct flashctx *const flash,
 
 			msg_cdbg("Switched to 4-bytes addressing mode.\n");
 		}
+		/* Do not switch to 4-Bytes Addressing mode if all instructions are direct-4BA
+		   or if the flash chip is 4-Bytes Addressing Only and always in 4BA-mode */
+		else {
+			msg_cdbg2("No need to switch to 4-bytes addressing mode.\n");
+		}
 	}
 
 	return 0;