TCPMv2: Replace charging allow list

Replace the charging allow list with a check to verify whether the
partner can provide at least 27W to the DUT.  This should cover existing
members of the allow list, and deprecate the need to continue adding to
this list.

BRANCH=None
BUG=b:173070679
TEST=on drawcia, verify DUT can charge from power bank, Apple 3-in-1,
and servo_v4

Signed-off-by: Diana Z <dzigterman@chromium.org>
Change-Id: Id0b516782809b6912602e9b7ab0546938e0b85ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2535217
Tested-by: Devin Lu <Devin.Lu@quantatw.com>
Reviewed-by: Denis Brockus <dbrockus@chromium.org>
Commit-Queue: Denis Brockus <dbrockus@chromium.org>

2 files changed, 38 insertions, 34 deletions

diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c
index f9b799f7e4..aa2eb9ad47 100644
--- a/common/usbc/usb_pe_drp_sm.c
+++ b/common/usbc/usb_pe_drp_sm.c
@@ -1426,59 +1426,63 @@ static void pe_send_request_msg(int port)
 	send_data_msg(port, TCPC_TX_SOP, PD_DATA_REQUEST);
 }
 
-static void pe_update_pdo_flags(int port, uint32_t pdo)
+static void pe_update_src_pdo_flags(int port, int pdo_cnt, uint32_t *pdos)
 {
-	int charge_allowlisted;
-
-	if (IS_ENABLED(CONFIG_CHARGE_MANAGER)) {
-		if (IS_ENABLED(CONFIG_USB_PD_ALT_MODE_DFP)) {
-			charge_allowlisted =
-				(pd_get_power_role(port) == PD_ROLE_SINK &&
-				 pd_charge_from_device(
-						pd_get_identity_vid(port),
-						pd_get_identity_pid(port)));
-		} else {
-			charge_allowlisted = 0;
-		}
-	}
-
-	/* can only parse PDO flags if type is fixed */
-	if ((pdo & PDO_TYPE_MASK) != PDO_TYPE_FIXED)
+	/*
+	 * Only parse PDO flags if type is fixed
+	 *
+	 * Note: From 6.4.1 Capabilities Message "The vSafe5V Fixed Supply
+	 * Object Shall always be the first object." so hitting this condition
+	 * would mean the partner is voilating spec.
+	 */
+	if ((pdos[0] & PDO_TYPE_MASK) != PDO_TYPE_FIXED)
 		return;
 
-	if (pdo & PDO_FIXED_DUAL_ROLE)
+	if (pdos[0] & PDO_FIXED_DUAL_ROLE)
 		tc_partner_dr_power(port, 1);
 	else
 		tc_partner_dr_power(port, 0);
 
-	if (pdo & PDO_FIXED_UNCONSTRAINED)
+	if (pdos[0] & PDO_FIXED_UNCONSTRAINED)
 		tc_partner_unconstrainedpower(port, 1);
 	else
 		tc_partner_unconstrainedpower(port, 0);
 
 	/* Do not set USB comm if we are in an alt-mode */
 	if (pe[port].partner_amodes[TCPC_TX_SOP].amode_idx == 0) {
-		if (pdo & PDO_FIXED_COMM_CAP)
+		if (pdos[0] & PDO_FIXED_COMM_CAP)
 			tc_partner_usb_comm(port, 1);
 		else
 			tc_partner_usb_comm(port, 0);
 	}
 
-	if (pdo & PDO_FIXED_DATA_SWAP)
+	if (pdos[0] & PDO_FIXED_DATA_SWAP)
 		tc_partner_dr_data(port, 1);
 	else
 		tc_partner_dr_data(port, 0);
 
 	/*
 	 * Treat device as a dedicated charger (meaning we should charge
-	 * from it) if it does not support power swap, or if it is unconstrained
-	 * power, or if we are a sink and the device identity matches a
-	 * charging allow-list.
+	 * from it) if:
+	 *   - it does not support power swap, or
+	 *   - it is unconstrained power, or
+	 *   - it presents at least 27 W of available power
 	 */
 	if (IS_ENABLED(CONFIG_CHARGE_MANAGER)) {
-		if (!(pdo & PDO_FIXED_DUAL_ROLE) ||
-		    (pdo & PDO_FIXED_UNCONSTRAINED) ||
-		    charge_allowlisted) {
+		uint32_t max_ma, max_mv, max_pdo, max_mw;
+
+		/*
+		 * Get max power that the partner offers (not necessarily what
+		 * this board will request)
+		 */
+		pd_find_pdo_index(pdo_cnt, pdos, PD_REV3_MAX_VOLTAGE,
+				  &max_pdo);
+		pd_extract_pdo_power(max_pdo, &max_ma, &max_mv);
+		max_mw = max_ma*max_mv/1000;
+
+		if (!(pdos[0] & PDO_FIXED_DUAL_ROLE) ||
+		    (pdos[0] & PDO_FIXED_UNCONSTRAINED) ||
+		    max_mw >= PD_DRP_CHARGE_POWER_MIN) {
 			PE_CLR_FLAG(port, PE_FLAGS_PORT_PARTNER_IS_DUALROLE);
 			charge_manager_update_dualrole(port, CAP_DEDICATED);
 		} else {
@@ -2777,8 +2781,7 @@ static void pe_snk_evaluate_capability_entry(int port)
 
 	pd_set_src_caps(port, num, pdo);
 
-	/* src cap 0 should be fixed PDO */
-	pe_update_pdo_flags(port, pdo[0]);
+	pe_update_src_pdo_flags(port, num, pdo);
 
 	/* Evaluate the options based on supplied capabilities */
 	pd_process_source_cap(port, pe[port].src_cap_cnt, pe[port].src_caps);
@@ -5051,11 +5054,6 @@ static void pe_init_port_vdm_identity_request_run(int port)
 		/* PE_INIT_PORT_VDM_Identity_ACKed embedded here */
 		dfp_consume_identity(port, sop, cnt, payload);
 
-		/* Evaluate whether this is an allow-listed charger */
-		if (IS_ENABLED(CONFIG_CHARGE_MANAGER) &&
-		    pd_charge_from_device(pd_get_identity_vid(port),
-					  pd_get_identity_pid(port)))
-			charge_manager_update_dualrole(port, CAP_DEDICATED);
 		break;
 		}
 	case VDM_RESULT_NAK:
diff --git a/include/usb_pd.h b/include/usb_pd.h
index 055008efd3..640cbba7ed 100644
--- a/include/usb_pd.h
+++ b/include/usb_pd.h
@@ -249,6 +249,12 @@ enum pd_rx_errors {
 #define PD_V_SINK_DISCONNECT_MAX 3670
 /* TODO(b/149530538): Add equation for vSinkDisconnectPD */
 
+/* Maximum voltage in mV offered by PD 3.0 Version 2.0 Spec */
+#define PD_REV3_MAX_VOLTAGE	20000
+
+/* Power in mW at which we will automatically charge from a DRP partner */
+#define PD_DRP_CHARGE_POWER_MIN	27000
+
 /* function table for entered mode */
 struct amode_fx {
 	int (*status)(int port, uint32_t *payload);