t6041-j575c: SuperSpeed for USB3 devices attached at boot (renegotiate inherited Type-C connections)

Documentation/devicetree/bindings/usb/apple,sn201202x.yaml

@@ -71,10 +71,13 @@ properties:
 
   apple,reset-inherited-usb2-connection:
     type: boolean
-    description:
-      The boot USB port retains a USB2 repeater connection that cannot be
-      recovered by resetting the host PHY. Renegotiate a normal application
-      connection before starting the host controllers. Debug routes are preserved.
+    description: |
+      A connection that is up when the OS starts keeps state from the boot
+      chain that resetting the host PHY does not recover: a USB2 repeater
+      connection on the boot port (J716c), or a Type-C retimer set up before
+      the host PHY ran, which keeps SuperSpeed from training (J575c).
+      Renegotiate a normal application connection before starting the host
+      controllers. Debug routes are preserved.
 
 required:
   - compatible

arch/arm64/boot/dts/apple/t6041-j575c-atc3.dtsi

@@ -114,6 +114,8 @@
 			     <95 IRQ_TYPE_EDGE_RISING>,
 			     <97 IRQ_TYPE_EDGE_RISING>;
 		interrupt-names = "irq", "select", "sleep", "wake";
+		/* Retimer set up before Linux keeps SuperSpeed down until replugged. */
+		apple,reset-inherited-usb2-connection;
 
 		typec3: connector {
 			compatible = "usb-c-connector";

arch/arm64/boot/dts/apple/t6041-j575c.dts

@@ -1409,6 +1409,8 @@
 			     <43 IRQ_TYPE_EDGE_RISING>,
 			     <45 IRQ_TYPE_EDGE_RISING>;
 		interrupt-names = "irq", "select", "sleep", "wake";
+		/* Retimer set up before Linux keeps SuperSpeed down until replugged. */
+		apple,reset-inherited-usb2-connection;
 
 		typec1: connector {
 			compatible = "usb-c-connector";
@@ -1438,6 +1440,8 @@
 			     <69 IRQ_TYPE_EDGE_RISING>,
 			     <71 IRQ_TYPE_EDGE_RISING>;
 		interrupt-names = "irq", "select", "sleep", "wake";
+		/* Retimer set up before Linux keeps SuperSpeed down until replugged. */
+		apple,reset-inherited-usb2-connection;
 
 		typec2: connector {
 			compatible = "usb-c-connector";

drivers/usb/typec/tipd/core.c

@@ -3168,27 +3168,80 @@ static int cd321x_remove(struct tps6598x *tps)
 	return 0;
 }
 
-static int cd321x_reset_inherited_connection(struct tps6598x *tps, u32 *status)
+/*
+ * Boards whose inherited boot connection must be renegotiated. The port
+ * controller key is the reversed target identifier.
+ *
+ * J716c: the boot port keeps a USB2 repeater connection.
+ * J575c: a connection that was up before Linux keeps its Type-C retimer set up
+ * from before the host PHY ran, so SuperSpeed stays in RxDetect until the
+ * partner is replugged. Byte 7 of register 0x7e has bit 3 set once the
+ * controller has completed an attach with the OS running (after a replug, and
+ * under macOS) and bit 2 in the inherited state; renegotiate only without
+ * bit 3. A failure leaves the port as it was (USB2 only) instead of failing
+ * the probe.
+ */
+#define CD321X_ATTACH_STATE_REG		0x7e
+#define CD321X_ATTACH_STATE_BYTE	7
+#define CD321X_ATTACH_STATE_DONE	BIT(3)
+
+struct cd321x_inherited_board {
+	const char *compatible;
+	u8 key[4];
+	bool check_attach_state;
+	bool best_effort;
+};
+
+static const struct cd321x_inherited_board cd321x_inherited_boards[] = {
+	{ .compatible = "apple,j716c", .key = { '6', '1', '7', 'J' } },
+	{ .compatible = "apple,j575c", .key = { '5', '7', '5', 'J' },
+	  .check_attach_state = true, .best_effort = true },
+};
+
+static const struct cd321x_inherited_board *cd321x_inherited_board(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(cd321x_inherited_boards); i++)
+		if (of_machine_is_compatible(cd321x_inherited_boards[i].compatible))
+			return &cd321x_inherited_boards[i];
+	return NULL;
+}
+
+static int cd321x_attach_state_done(struct tps6598x *tps)
+{
+	u8 state[CD321X_ATTACH_STATE_BYTE + 1];
+	int ret;
+
+	ret = tps6598x_block_read(tps, CD321X_ATTACH_STATE_REG, state, sizeof(state));
+	if (ret)
+		return ret;
+	dev_dbg(tps->dev, "inherited connection, attach state 0x%02x\n",
+		state[CD321X_ATTACH_STATE_BYTE]);
+	return !!(state[CD321X_ATTACH_STATE_BYTE] & CD321X_ATTACH_STATE_DONE);
+}
+
+static int __cd321x_reset_inherited_connection(struct tps6598x *tps,
+						const struct cd321x_inherited_board *board,
+						u32 *status)
 {
-	/* J716c's port-controller key is the reversed target identifier J716. */
-	static const u8 key[] = { '6', '1', '7', 'J' };
 	static const u8 locked[4];
 	u8 delay = 5, result;
 	unsigned long timeout;
 	int ret, lock_ret, mode;
 
-	if (!device_property_read_bool(tps->dev, "apple,reset-inherited-usb2-connection") ||
-	    !of_machine_is_compatible("apple,j716c") ||
-	    !device_is_compatible(tps->dev, "apple,sn201202x") ||
-	    tps->dbma_at_probe || !(*status & TPS_STATUS_PLUG_PRESENT) ||
-	    !TPS_STATUS_TO_TYPEC_DATAROLE(*status))
-		return 0;
 	mode = tps6598x_check_mode(tps);
 	if (mode != TPS_MODE_APP && mode != TPS_MODE_APP1)
 		return 0;
+	if (board->check_attach_state) {
+		ret = cd321x_attach_state_done(tps);
+		if (ret)
+			return ret < 0 ? ret : 0;
+	}
 
 	/* All suppliers are available, but no USB or router session has started. */
-	ret = tps6598x_exec_cmd(tps, "LOCK", sizeof(key), key, sizeof(result), &result);
+	ret = tps6598x_exec_cmd(tps, "LOCK", sizeof(board->key), board->key, sizeof(result),
+				&result);
 	if (ret)
 		return ret;
 	if (result) {
@@ -3224,7 +3277,32 @@ static int cd321x_reset_inherited_connection(struct tps6598x *tps, u32 *status)
 	if (!tps6598x_read_status(tps, status))
 		return -EIO;
 	tps->status = *status;
-	dev_info(tps->dev, "reinitialized inherited USB2 connection\n");
+	dev_info(tps->dev, "reinitialized inherited connection\n");
+	return 0;
+}
+
+static int cd321x_reset_inherited_connection(struct tps6598x *tps, u32 *status)
+{
+	const struct cd321x_inherited_board *board;
+	int ret;
+
+	if (!device_property_read_bool(tps->dev, "apple,reset-inherited-usb2-connection") ||
+	    !device_is_compatible(tps->dev, "apple,sn201202x") ||
+	    tps->dbma_at_probe || !(*status & TPS_STATUS_PLUG_PRESENT) ||
+	    !TPS_STATUS_TO_TYPEC_DATAROLE(*status))
+		return 0;
+	board = cd321x_inherited_board();
+	if (!board)
+		return 0;
+
+	ret = __cd321x_reset_inherited_connection(tps, board, status);
+	if (!ret || !board->best_effort)
+		return ret;
+
+	dev_warn(tps->dev, "inherited connection not reinitialized: %d\n", ret);
+	if (!tps6598x_read_status(tps, status))
+		return -EIO;
+	tps->status = *status;
 	return 0;
 }
 

drivers/usb/typec/tipd/spmi.c

@@ -995,6 +995,11 @@ static struct spmi_driver sn201202x_driver = {
 		.name = "sn201202x",
 		.pm = &sn201202x_pm_ops,
 		.of_match_table = sn201202x_of_match,
+		/*
+		 * Renegotiating an inherited connection waits several seconds per
+		 * port; let the ports of one machine probe at the same time.
+		 */
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
 	.probe = sn201202x_probe,
 	.remove = sn201202x_remove,