link: Don't print keyboard state changes by default

The keyboard scan module generates a lot of debug output when the user
is typing on the keyboard - enough so that switching to the console,
logging in as root, and typing 'ectool console' flushes the EC's
console output buffer of any useful data.  Default printing this to
off.  Add a new 'ksstate' command which will print the current
keyboard scan state or toggle printing off/on.

This is important for debugging LPC communication failures.

BUG=chrome-os-partner:13819
BRANCH=link
TEST=manual

- Boot system
- Type on keyboard.  At EC console, should not see KB state: output
- Hold down space bar.
- At EC console, type 'ksstate'.  Should print:
  ksstate
  [20.943886 KB debounced : -- -- -- -- -- -- -- -- -- -- -- 20 --]
  [20.945215 KB prev      : -- -- -- -- -- -- -- -- -- -- -- 20 --]
  [20.945568 KB debouncing: -- -- -- -- -- -- -- -- -- -- -- -- --]
  Keyboard scan state printing off
- Release space bar
- At EC console, type 'ksstate on'
- Type on keyboard.  Should see KB state: output
- At EC console, type 'ksstate off'
- Type on keyboard.  At EC console, should not see KB state: output

Change-Id: I4343b7b777fd13057b3222eeba77ed099c5e5a93
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/35843
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>

1 files changed, 34 insertions, 1 deletions

diff --git a/chip/lm4/keyboard_scan.c b/chip/lm4/keyboard_scan.c
index ef7dfd6b94..f2f26faca2 100644
--- a/chip/lm4/keyboard_scan.c
+++ b/chip/lm4/keyboard_scan.c
@@ -67,6 +67,12 @@ static const uint8_t actual_key_masks[4][KB_COLS] = {
 	{0},
 	};
 
+/*
+ * Print all keyboard scan state changes?  Off by default because it generates
+ * a lot of debug output, which makes the saved EC console data less useful.
+ */
+static int print_state_changes;
+
 /* Key masks for special boot keys */
 #define MASK_INDEX_REFRESH 2
 #define MASK_VALUE_REFRESH 0x04
@@ -322,7 +328,7 @@ static int check_keys_changed(uint8_t *state)
 		}
 	}
 
-	if (any_change) {
+	if (any_change && print_state_changes) {
 		print_state(state, "state");
 
 #ifdef PRINT_SCAN_TIMES
@@ -510,3 +516,30 @@ void keyboard_enable_scanning(int enable)
 		keyboard_clear_underlying_buffer();
 	}
 }
+
+/*****************************************************************************/
+/* Console commands*/
+
+static int command_ksstate(int argc, char **argv)
+{
+	if (argc > 1) {
+		if (!strcasecmp(argv[1], "on"))
+			print_state_changes = 1;
+		else if (!strcasecmp(argv[1], "off"))
+			print_state_changes = 0;
+		else
+			return EC_ERROR_PARAM1;
+	} else {
+		print_state(debounced_state, "debounced ");
+		print_state(prev_state, "prev      ");
+		print_state(debouncing, "debouncing");
+	}
+
+	ccprintf("Keyboard scan state printing %s\n",
+		 print_state_changes ? "on" : "off");
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(ksstate, command_ksstate,
+			"ksstate [on | off]",
+			"Show or toggle printing keyboard scan state",
+			NULL);