lm4: Report raw DID value when chip name cannot be determined

We map the raw DID value to chip name in EC. If the raw value is not in
the mapping table, EC just returns empty string and we lose this
information from host side. Let's return raw DID value like
"Unknown-10ea".

BUG=chrome-os-partner:15519
TEST=remove 0x10ea from the mapping and check 'mosys -k ec info' shows
'Unknown-10ea'.
BRANCH=link

Change-Id: I9399f44ab40db02202ee03ba3f988f3ece010d9f
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/36305
Reviewed-by: David Hendricks <dhendrix@chromium.org>

1 files changed, 26 insertions, 1 deletions

diff --git a/chip/lm4/system.c b/chip/lm4/system.c
index 7af9a3aca5..d69942e85c 100644
--- a/chip/lm4/system.c
+++ b/chip/lm4/system.c
@@ -387,6 +387,31 @@ const char *system_get_chip_vendor(void)
 	return "ti";
 }
 
+static char to_hex(int x)
+{
+	if (x >= 0 && x <= 9)
+		return '0' + x;
+	return 'a' + x - 10;
+}
+
+const char *system_get_raw_chip_name(void)
+{
+	static char str[15] = "Unknown-";
+	char *p = str + 8;
+	uint32_t did = LM4_SYSTEM_DID1 >> 16;
+
+	if (*p)
+		return (const char *)str;
+
+	*p = to_hex(did >> 12);
+	*(p + 1) = to_hex((did >> 8) & 0xf);
+	*(p + 2) = to_hex((did >> 4) & 0xf);
+	*(p + 3) = to_hex(did & 0xf);
+	*(p + 4) = '\0';
+
+	return (const char *)str;
+}
+
 const char *system_get_chip_name(void)
 {
 	if ((LM4_SYSTEM_DID1 & 0xffff0000) == 0x10e20000) {
@@ -400,7 +425,7 @@ const char *system_get_chip_name(void)
 	} else if ((LM4_SYSTEM_DID1 & 0xffff0000) == 0x10ea0000) {
 		return "lm4fs1gh5bb";
 	} else {
-		return "";
+		return system_get_raw_chip_name();
 	}
 }