Enhance port 80 logging

- 'port80 intprint' toggles printing port 80 codes in interrupt
  handler (turning that off speeds up port 80 capture a bit, if you're
  sending port 80 codes very rapidly)

- 'port80 flush' flushes the log buffer

- log buffer expanded to 256 entries

- log buffer tracks S3->S0 power state transitions, so you can tell
  where each boot starts

This uses ~500 bytes more RAM on the EC, but we've got piles of RAM
(with this change we're using 17KB out of 32KB).

BUG=none
TEST=manual

- boot system
- port80 -> prints data
- port80 intprint -> now disabled
- reboot; wait for reboot; no port80 debug output during boot
- port80 -> prints data from previous boot AND this one
- port80 flush
- port80 -> nothing in log

Change-Id: I64ee72fb13ab0fdd85d04b9640b5390fdac31400
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/29420
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

1 files changed, 9 insertions, 1 deletions

diff --git a/include/port80.h b/include/port80.h
index 787af8c169..0d251d1d1f 100644
--- a/include/port80.h
+++ b/include/port80.h
@@ -10,7 +10,15 @@
 
 #include "common.h"
 
-/* Called by LPC module when a byte of data is written to port 80. */
+enum port_80_event {
+	PORT_80_EVENT_RESUME = 0x1001,  /* S3->S0 transition */
+};
+
+/**
+ * Store data from a LPC write to port 80, or a port_80_event code.
+ *
+ * @param data		Data written to port 80.
+ */
 void port_80_write(int data);
 
 #endif  /* __CROS_EC_PORT80_H */