Bluetooth: hci_qca: Make bt_en and susclk not mandatory for QCA Rome

On some platforms the bt_en pin and susclk are default on and there
is no exposed resource to control them. This patch makes the bt_en
and susclk not mandatory to have BT work. It also will not set the
HCI_QUIRK_NON_PERSISTENT_SETUP and shutdown() callback if bt_en is
not available.
Signed-off-by: Rocky Liao <rjliao@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/hci_qca.c

@@ -1562,9 +1562,11 @@ static int qca_power_on(struct hci_dev *hdev)
 		ret = qca_wcn3990_init(hu);
 	} else {
 		qcadev = serdev_device_get_drvdata(hu->serdev);
-		gpiod_set_value_cansleep(qcadev->bt_en, 1);
-		/* Controller needs time to bootup. */
-		msleep(150);
+		if (!IS_ERR(qcadev->bt_en)) {
+			gpiod_set_value_cansleep(qcadev->bt_en, 1);
+			/* Controller needs time to bootup. */
+			msleep(150);
+		}
 	}
 
 	return ret;
@@ -1750,7 +1752,7 @@ static void qca_power_shutdown(struct hci_uart *hu)
 		host_set_baudrate(hu, 2400);
 		qca_send_power_pulse(hu, false);
 		qca_regulator_disable(qcadev);
-	} else {
+	} else if (!IS_ERR(qcadev->bt_en)) {
 		gpiod_set_value_cansleep(qcadev->bt_en, 0);
 	}
 }
@@ -1852,6 +1854,7 @@ static int qca_serdev_probe(struct serdev_device *serdev)
 	struct hci_dev *hdev;
 	const struct qca_vreg_data *data;
 	int err;
+	bool power_ctrl_enabled = true;
 
 	qcadev = devm_kzalloc(&serdev->dev, sizeof(*qcadev), GFP_KERNEL);
 	if (!qcadev)
@@ -1901,35 +1904,37 @@ static int qca_serdev_probe(struct serdev_device *serdev)
 		qcadev->bt_en = devm_gpiod_get(&serdev->dev, "enable",
 					       GPIOD_OUT_LOW);
 		if (IS_ERR(qcadev->bt_en)) {
-			dev_err(&serdev->dev, "failed to acquire enable gpio\n");
-			return PTR_ERR(qcadev->bt_en);
+			dev_warn(&serdev->dev, "failed to acquire enable gpio\n");
+			power_ctrl_enabled = false;
 		}
 
 		qcadev->susclk = devm_clk_get(&serdev->dev, NULL);
 		if (IS_ERR(qcadev->susclk)) {
-			dev_err(&serdev->dev, "failed to acquire clk\n");
-			return PTR_ERR(qcadev->susclk);
-		}
-
-		err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ);
-		if (err)
-			return err;
+			dev_warn(&serdev->dev, "failed to acquire clk\n");
+		} else {
+			err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ);
+			if (err)
+				return err;
 
-		err = clk_prepare_enable(qcadev->susclk);
-		if (err)
-			return err;
+			err = clk_prepare_enable(qcadev->susclk);
+			if (err)
+				return err;
+		}
 
 		err = hci_uart_register_device(&qcadev->serdev_hu, &qca_proto);
 		if (err) {
 			BT_ERR("Rome serdev registration failed");
-			clk_disable_unprepare(qcadev->susclk);
+			if (!IS_ERR(qcadev->susclk))
+				clk_disable_unprepare(qcadev->susclk);
 			return err;
 		}
 	}
 
-	hdev = qcadev->serdev_hu.hdev;
-	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
-	hdev->shutdown = qca_power_off;
+	if (power_ctrl_enabled) {
+		hdev = qcadev->serdev_hu.hdev;
+		set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
+		hdev->shutdown = qca_power_off;
+	}
 
 	return 0;
 }
@@ -1940,7 +1945,7 @@ static void qca_serdev_remove(struct serdev_device *serdev)
 
 	if (qca_is_wcn399x(qcadev->btsoc_type))
 		qca_power_shutdown(&qcadev->serdev_hu);
-	else
+	else if (!IS_ERR(qcadev->susclk))
 		clk_disable_unprepare(qcadev->susclk);
 
 	hci_uart_unregister_device(&qcadev->serdev_hu);