4BA: Allow disabling 4-byte address mode for SPI flash

This allows us to support flash chips in any of the following
configurations, regardless of whether the chip powers up in 3-byte or
4-byte address mode.

- standard commands with extended address register (*_4ba_ereg) or
  direct commands (*_4ba_direct) in 3-byte address mode (.set_4ba =
  spi_exit_4ba_*)
- standard commands (*_4ba) or direct commands (*_4ba_direct) in
  4-byte address mode (.set_4ba = spi_enter_4ba_*)
- direct commands (*_4ba_direct) in either address mode (.set_4ba =
  NULL)

Change-Id: I0b25309d731426940fc50956b744b681ab599e87
Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
Reviewed-on: https://review.coreboot.org/20510
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 6 insertions, 35 deletions

diff --git a/flashrom.c b/flashrom.c
index 8569a4960..4f17382dc 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -2223,41 +2223,12 @@ int prepare_flash_access(struct flashctx *const flash,
 	if (flash->chip->unlock)
 		flash->chip->unlock(flash);
 
-	/* Switching to 4-Bytes Addressing mode if flash chip supports it */
-	if(flash->chip->feature_bits & FEATURE_4BA_SUPPORT) {
-		/* Do not switch if chip is already in 4-bytes addressing mode */
-		if (flash->chip->feature_bits & FEATURE_4BA_ONLY) {
-			msg_cdbg("Flash chip is already in 4-bytes addressing mode.\n");
-		}
-		/* Do not switch to 4-Bytes Addressing mode if using Extended Address Register */
-		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 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");
-				return 1;
-			}
-
-			if(flash->chip->four_bytes_addr_funcs.enter_4ba(flash)) {
-				msg_cerr("Switching to 4-bytes addressing mode failed!\n");
-				return 1;
-			}
-
-			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");
+	/* Enable/disable 4-byte addressing mode if flash chip supports it */
+	if ((flash->chip->feature_bits & FEATURE_4BA_SUPPORT) &&
+	    flash->chip->four_bytes_addr_funcs.set_4ba) {
+		if (flash->chip->four_bytes_addr_funcs.set_4ba(flash)) {
+			msg_cerr("Enabling/disabling 4-byte addressing mode failed!\n");
+			return 1;
 		}
 	}