TCPMv2: Do not apply CC Open when running without battery

This patch prevents applying CC Open when there is no battery.
On some boards EC RO doesn't save power-on reset flag in BBRAM when
EC reboot by Cr50 is expected. This behaviour was implemented in
CL:2255830. Brown-out reset flag is implemented only for LM4 chips.

Also we don't have access to information stored by TCPMv1 in BBRAM.
This functionality was removed from TCPMv2 in CL:2271002, so we can't
really determine if we should apply CC Open and from that time we are
applying CC Open always, except power-on and brown-out reset flags.
This patch adds missing battery to list of exceptions.

BUG=b:161775827
BRANCH=none
TEST=Flash EC ToT on Fleex. Disconnect battery physically and plug
     charger. Check if ChromeOS boots successfully.

Signed-off-by: Patryk Duda <pdk@semihalf.com>
Change-Id: Icc22fcce595693c744e1a55b905cdd58b5e7bfbd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2767638
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Diana Z <dzigterman@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2785213
Tested-by: Abe Levkoy <alevkoy@chromium.org>
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>
Commit-Queue: Abe Levkoy <alevkoy@chromium.org>

1 files changed, 25 insertions, 2 deletions

diff --git a/common/usbc/usb_tc_drp_acc_trysrc_sm.c b/common/usbc/usb_tc_drp_acc_trysrc_sm.c
index 4867ae28d4..8daf8704e2 100644
--- a/common/usbc/usb_tc_drp_acc_trysrc_sm.c
+++ b/common/usbc/usb_tc_drp_acc_trysrc_sm.c
@@ -1518,6 +1518,13 @@ void tc_state_init(int port)
 #endif
 
 	/*
+	 * We are going to apply CC open (start with ErrorRecovery state)
+	 * unless there is something which forbids us to do that (one of
+	 * conditions below is true)
+	 */
+	first_state = TC_ERROR_RECOVERY;
+
+	/*
 	 * If we just lost power, don't apply CC open. Otherwise we would boot
 	 * loop, and if this is a fresh power on, then we know there isn't any
 	 * stale PD state as well.
@@ -1525,12 +1532,28 @@ void tc_state_init(int port)
 	if (system_get_reset_flags() &
 	    (EC_RESET_FLAG_BROWNOUT | EC_RESET_FLAG_POWER_ON)) {
 		first_state = TC_UNATTACHED_SNK;
+	}
+
+	/*
+	 * If this is non-EFS2 device, battery is not present and EC RO doesn't
+	 * keep power-on reset flag after reset caused by H1, then don't apply
+	 * CC open because it will cause brown out.
+	 *
+	 * Please note that we are checking if CONFIG_BOARD_RESET_AFTER_POWER_ON
+	 * is defined now, but actually we need to know if it was enabled in
+	 * EC RO! It was assumed that if CONFIG_BOARD_RESET_AFTER_POWER_ON is
+	 * defined now it was defined in EC RO too.
+	 */
+	if (!IS_ENABLED(CONFIG_BOARD_RESET_AFTER_POWER_ON) &&
+	    !IS_ENABLED(CONFIG_VBOOT_EFS2) && IS_ENABLED(CONFIG_BATTERY) &&
+	    (battery_is_present() == BP_NO)) {
+		first_state = TC_UNATTACHED_SNK;
+	}
 
+	if (first_state == TC_UNATTACHED_SNK) {
 		/* Turn off any previous sourcing */
 		tc_src_power_off(port);
 		set_vconn(port, 0);
-	} else {
-		first_state = TC_ERROR_RECOVERY;
 	}
 
 #ifdef CONFIG_USB_PD_TCPC_BOARD_INIT