Add new event for host interface ready

Also add new 'invalid' host event bit; if the host reads this, it
knows the memory-mapped data for current events is invalid.

BUG=chrome-os-partner:11146
TEST=manual

On host, ectool eventget -> should print events = 0
On EC, hostevent set 0x80000000
On host, ectool eventget -> should print events = invalid

Reboot EC; should see debug output where event mask 0x2000 is set
during the boot process.

Signed-off-by: Randall Spangler <rspangler@chromium.org>
Change-Id: I8d3f161eec25db50ac06e3642a1a1fb8edb9590e
Reviewed-on: https://gerrit.chromium.org/gerrit/26876

4 files changed, 30 insertions, 6 deletions

diff --git a/chip/lm4/lpc.c b/chip/lm4/lpc.c
index 26fcb39931..6db8d1c096 100644
--- a/chip/lm4/lpc.c
+++ b/chip/lm4/lpc.c
@@ -284,6 +284,7 @@ void lpc_set_host_events(uint32_t mask)
 		return;
 
 	host_events |= mask;
+	CPRINTF("[%T event set 0x%08x -> %08x]\n", mask, host_events);
 	update_host_event_status();
 }
 
@@ -294,6 +295,7 @@ void lpc_clear_host_events(uint32_t mask)
 		return;
 
 	host_events &= ~mask;
+	CPRINTF("[%T event clear 0x%08x -> %08x]\n", mask, host_events);
 	update_host_event_status();
 }
 
diff --git a/common/host_command.c b/common/host_command.c
index 3647e50cda..99de6e057b 100644
--- a/common/host_command.c
+++ b/common/host_command.c
@@ -176,7 +176,7 @@ enum ec_status host_command_process(int slot, int command, uint8_t *data,
 	const struct host_command *cmd = find_host_command(command);
 	enum ec_status res = EC_RES_INVALID_COMMAND;
 
-	CPRINTF("[hostcmd%d 0x%02x]\n", slot, command);
+	CPRINTF("[%T hostcmd%d 0x%02x]\n", slot, command);
 
 	*response_size = 0;
 	if (cmd)
@@ -191,24 +191,26 @@ static void command_process(int slot)
 	int size;
 	int res;
 
-	CPRINTF("[hostcmd%d 0x%02x]\n", slot, host_command[slot]);
+	CPRINTF("[%T hostcmd%d 0x%02x]\n", slot, host_command[slot]);
 
 	res = host_command_process(slot, host_command[slot],
 				   host_get_buffer(slot), &size);
 
 	host_send_response(slot, res, host_get_buffer(slot), size);
 }
+
 /*****************************************************************************/
 /* Initialization / task */
 
 static int host_command_init(void)
 {
 	host_command[0] = host_command[1] = -1;
+	host_set_single_event(EC_HOST_EVENT_INTERFACE_READY);
+	CPRINTF("[%T hostcmd init 0x%x]\n", host_get_events());
 
 	return EC_SUCCESS;
 }
 
-
 void host_command_task(void)
 {
 	host_command_init();
diff --git a/include/ec_commands.h b/include/ec_commands.h
index e4499302d9..baa770d5e3 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -161,9 +161,23 @@ enum host_event_code {
 	EC_HOST_EVENT_THERMAL = 11,
 	EC_HOST_EVENT_USB_CHARGER = 12,
 	EC_HOST_EVENT_KEY_PRESSED = 13,
+	/*
+	 * EC has finished initializing the host interface.  The host can check
+	 * for this event following sending a EC_CMD_REBOOT_EC command to
+	 * determine when the EC is ready to accept subsequent commands.
+	 */
+	EC_HOST_EVENT_INTERFACE_READY = 14,
+	/*
+	 * The high bit of the event mask is not used as a host event code.  If
+	 * it reads back as set, then the entire event mask should be
+	 * considered invalid by the host.  This can happen when reading the
+	 * raw event status via EC_MEMMAP_HOST_EVENTS but the LPC interface is
+	 * not initialized on the EC, or improperly configured on the host.
+	 */
+	EC_HOST_EVENT_INVALID = 32
 };
 /* Host event mask */
-#define EC_HOST_EVENT_MASK(event_code) (1 << ((event_code) - 1))
+#define EC_HOST_EVENT_MASK(event_code) (1UL << ((event_code) - 1))
 
 /*
  * Notes on commands:
diff --git a/util/ectool.c b/util/ectool.c
index 2b1078323b..c04ff39d9a 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -1251,8 +1251,14 @@ int cmd_acpi_query_ec(int argc, char *argv[])
 
 int cmd_host_event_get_raw(int argc, char *argv[])
 {
-	printf("Current host events: 0x%08x\n",
-	       read_mapped_mem32(EC_MEMMAP_HOST_EVENTS));
+	uint32_t events = read_mapped_mem32(EC_MEMMAP_HOST_EVENTS);
+
+	if (events & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INVALID)) {
+		printf("Current host events: invalid\n");
+		return -1;
+	}
+
+	printf("Current host events: 0x%08x\n", events);
 	return 0;
 }