charge_manager: Add charge port override functionality

Allow a charge port to be selected as the override port, which means it
will always be selected as the charge port, if any charge supplier is
available.

BUG=chrome-os-partner:32003
TEST=Attach PD charger and BC1.2 charger. Verify that active charge port
switches to BC1.2 after running `chargeoverride [port]` from console.
Also, pass unit tests.
BRANCH=Samus

Change-Id: Ia1b48ca89641842d51be7eed3b92d36d3eedc9ef
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/227730
Reviewed-by: Alec Berg <alecaberg@chromium.org>

1 files changed, 77 insertions, 21 deletions

diff --git a/common/charge_manager.c b/common/charge_manager.c
index 6926da4121..6b66d88a81 100644
--- a/common/charge_manager.c
+++ b/common/charge_manager.c
@@ -27,6 +27,7 @@ static int charge_ceil[PD_PORT_COUNT];
 static int charge_port = CHARGE_PORT_NONE;
 static int charge_current = CHARGE_CURRENT_UNINITIALIZED;
 static int charge_supplier = CHARGE_SUPPLIER_NONE;
+static int override_port = OVERRIDE_OFF;
 
 /**
  * Initialize available charge. Run before board init, so board init can
@@ -83,29 +84,45 @@ static void charge_manager_refresh(void)
 	int new_port = CHARGE_PORT_NONE;
 	int new_charge_current, new_charge_voltage, i, j, old_port;
 
-	/*
-	 * Charge supplier selection logic:
-	 * 1. Prefer higher priority supply.
-	 * 2. Prefer higher power over lower in case priority is tied.
-	 * available_charge can be changed at any time by other tasks,
-	 * so make no assumptions about its consistency.
-	 */
-	for (i = 0; i < CHARGE_SUPPLIER_COUNT; ++i)
-		for (j = 0; j < PD_PORT_COUNT; ++j)
-			if (available_charge[i][j].current > 0 &&
-			    available_charge[i][j].voltage > 0 &&
-			    (new_supplier == CHARGE_SUPPLIER_NONE ||
-			     supplier_priority[i] <
-			     supplier_priority[new_supplier] ||
-			    (supplier_priority[i] ==
-			     supplier_priority[new_supplier] &&
-			     POWER(available_charge[i][j]) >
-			     POWER(available_charge[new_supplier]
-						   [new_port])))) {
-				new_supplier = i;
-				new_port = j;
+	/* Skip port selection on OVERRIDE_DONT_CHARGE. */
+	if (override_port != OVERRIDE_DONT_CHARGE) {
+		/*
+		 * Charge supplier selection logic:
+		 * 1. Prefer higher priority supply.
+		 * 2. Prefer higher power over lower in case priority is tied.
+		 * available_charge can be changed at any time by other tasks,
+		 * so make no assumptions about its consistency.
+		 */
+		for (i = 0; i < CHARGE_SUPPLIER_COUNT; ++i)
+			for (j = 0; j < PD_PORT_COUNT; ++j) {
+				if (override_port != OVERRIDE_OFF &&
+				    override_port == new_port &&
+				    override_port != j)
+					continue;
+
+				if (available_charge[i][j].current > 0 &&
+				    available_charge[i][j].voltage > 0 &&
+				   (new_supplier == CHARGE_SUPPLIER_NONE ||
+				    supplier_priority[i] <
+				    supplier_priority[new_supplier] ||
+				   (j == override_port &&
+				    new_port != override_port) ||
+				   (supplier_priority[i] ==
+				    supplier_priority[new_supplier] &&
+				    POWER(available_charge[i][j]) >
+				    POWER(available_charge[new_supplier]
+							  [new_port])))) {
+					new_supplier = i;
+					new_port = j;
+				}
 			}
 
+		/* Clear override if no charge is available on override port */
+		if (override_port != OVERRIDE_OFF &&
+		    override_port != new_port)
+			override_port = OVERRIDE_OFF;
+	}
+
 	if (new_supplier == CHARGE_SUPPLIER_NONE)
 		new_charge_current = new_charge_voltage = 0;
 	else {
@@ -189,6 +206,25 @@ void charge_manager_set_ceil(int port, int ceil)
 	}
 }
 
+/**
+ * Select an 'override port', a port which is always the preferred charge port.
+ *
+ * @param port			Charge port to select as override, or
+ *				OVERRIDE_OFF to select no override port,
+ *				or OVERRIDE_DONT_CHARGE to specifc that no
+ *				charge port should be selected.
+ */
+void charge_manager_set_override(int port)
+{
+	ASSERT(port >= OVERRIDE_DONT_CHARGE && port < PD_PORT_COUNT);
+
+	if (override_port != port) {
+		override_port = port;
+		if (charge_manager_is_seeded())
+			hook_call_deferred(charge_manager_refresh, 0);
+	}
+}
+
 int charge_manager_get_active_charge_port(void)
 {
 	return charge_port;
@@ -291,3 +327,23 @@ DECLARE_HOST_COMMAND(EC_CMD_USB_PD_POWER_INFO,
 		     hc_pd_power_info,
 		     EC_VER_MASK(0));
 #endif /* TEST_CHARGE_MANAGER */
+
+static int command_charge_override(int argc, char **argv)
+{
+	int port = OVERRIDE_OFF;
+	char *e;
+
+	if (argc >= 2) {
+		port = strtoi(argv[1], &e, 0);
+		if (*e || port < OVERRIDE_DONT_CHARGE || port >= PD_PORT_COUNT)
+			return EC_ERROR_PARAM1;
+	}
+
+	charge_manager_set_override(port);
+	ccprintf("Set override: %d\n", port);
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(chargeoverride, command_charge_override,
+	"[port | -1 | -2]",
+	"Force charging from a given port (-1 = off, -2 = disable charging)",
+	NULL);