TCPMv2: Enable TCPC low power when port is looking for a connection

When the port is in a state where it is looking for a connection,
to save power, we should put the TCPC in its low power mode and
enable auto toggling. Low power mode can happen when DRP auto
toggling, acting as a SNK only, or acting as a SRC only.

BUG=chromium:1022217
BRANCH=none
TEST=make -j buildall
	manual tests:
	1: (S0) Nothing plugged in, port is drp and low power mode
	2: (S5/S3/S0ix) Port is SNK only, and low power with nothing plugged in
	3: (S3/S0ix) If TypeC sink was previously plugged in, port remains powered
	4: (S5/S3/S0ix) TypeC source is recognized
	5: (S3->S0) TypeC sink plugged in, port is powered when S0 is reached

	Low power exit test:

	Using this command from the AP console:

	ectool i2cread 8 2 0x16 0x0d
	Transfer failed with status=0x1 # This means the TCPC was asleep.

	On the EC console:

	2019-11-21 09:50:24 [315.235538 TCPC p1 init ready]
	2019-11-21 09:50:24 [315.236048 TCPC p1 Exit Low Power Mode]
	2019-11-21 09:50:24 [315.242837 TCPC p1 init ready]
	2019-11-21 09:50:24 [315.243229 C1: DRPAutoToggle]
	2019-11-21 09:50:24 [315.246471 C1: Unattached.SNK]
	2019-11-21 09:50:24 [315.252504 C1: DRPAutoToggle]
	2019-11-21 09:50:24 [315.362878 C1: LowPowerMode]
	2019-11-21 09:50:24 [315.363314 TCPC p1 Enter Low Power Mode]

Change-Id: I7e853d05e0ece1f6b3031f17a18fcbf0d9a15a51
Signed-off-by: Sam Hurst <shurst@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1904974
Reviewed-by: Edward Hill <ecgh@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/include/usb_common.h b/include/usb_common.h
index 85260d539d..b35e5f27f9 100644
--- a/include/usb_common.h
+++ b/include/usb_common.h
@@ -10,6 +10,28 @@
 #include "usb_pd_tcpm.h"
 #include "task_id.h"
 
+enum pd_drp_next_states {
+	DRP_TC_DEFAULT,
+	DRP_TC_UNATTACHED_SNK,
+	DRP_TC_UNATTACHED_SRC,
+	DRP_TC_DRP_AUTO_TOGGLE
+};
+
+/**
+ * Returns the next state to transition to while in the drp auto toggle state.
+ *
+ * @param drp_sink_time timer for handling TOGGLE_OFF/FORCE_SINK mode when
+ *			auto-toggle enabled. This is an in/out variable.
+ * @param power_role current power role
+ * @param drp_state dual role states
+ * @param cc1 value of CC1 set by tcpm_get_cc
+ * @param cc2 value of CC2 set by tcpm_get_cc
+ *
+ */
+enum pd_drp_next_states drp_auto_toggle_next_state(uint64_t *drp_sink_time,
+	enum pd_power_role power_role, enum pd_dual_role_states drp_state,
+	enum tcpc_cc_voltage_status cc1, enum tcpc_cc_voltage_status cc2);
+
 /* Returns the battery percentage [0-100] of the system. */
 int usb_get_battery_soc(void);