Flashrom already has the following probe functions

- probe_spi_rdid with opcode 0x9f, usually 3 bytes ID
- probe_spi_res with opcode 0xab, usually 1 byte ID
We are missing the following probe function:
- probe_spi_rems with opcode 0x90, usually 2 bytes ID

RDID provides best specifity (manufacturer, device class and device) and
RES is supported by quite a few old chips. However, RES only returns one
byte and there are multiple flash chips with different sizes on the
market and all of them have the same RES ID.
REMS is from the same age as RES, but it provides a manufacturer and a
device ID. It is therefore on par with the probing for parallel flash
chips and specific enough.

The order in which chips should be detected is as follows:
1. RDID
2. REMS
3. RES

Corresponding to flashrom svn r349 and coreboot v2 svn r3775.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Peter Stuge <peter@stuge.se>

1 files changed, 5 insertions, 0 deletions

diff --git a/spi.h b/spi.h
index 54c71fc66..c096dce5c 100644
--- a/spi.h
+++ b/spi.h
@@ -29,6 +29,11 @@
 #define JEDEC_RDID_OUTSIZE	0x01
 #define JEDEC_RDID_INSIZE	0x03
 
+/* Read Electronic Manufacturer Signature */
+#define JEDEC_REMS		0x90
+#define JEDEC_REMS_OUTSIZE	0x04
+#define JEDEC_REMS_INSIZE	0x02
+
 /* Read Electronic Signature */
 #define JEDEC_RES		0xab
 #define JEDEC_RES_OUTSIZE	0x04