Bluetooth: hci_qca: Add poweroff support during hci down for wcn3990

This patch enables power off support for hci down and power on support
for hci up. As wcn3990 power sources are ignited by regulators, we will
turn off them during hci down, i.e. an complete power off of wcn3990.
So while hci up, will call vendor setup which will turn on the regulators,
requests BT chip version and download the firmware.
Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/hci_qca.c

@@ -168,6 +168,7 @@ struct qca_serdev {
 
 static int qca_power_setup(struct hci_uart *hu, bool on);
 static void qca_power_shutdown(struct hci_uart *hu);
+static int qca_power_off(struct hci_dev *hdev);
 
 static void __serial_clock_on(struct tty_struct *tty)
 {
@@ -1099,8 +1100,26 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type)
 static int qca_wcn3990_init(struct hci_uart *hu)
 {
 	struct hci_dev *hdev = hu->hdev;
+	struct qca_serdev *qcadev;
 	int ret;
 
+	/* Check for vregs status, may be hci down has turned
+	 * off the voltage regulator.
+	 */
+	qcadev = serdev_device_get_drvdata(hu->serdev);
+	if (!qcadev->bt_power->vregs_on) {
+		serdev_device_close(hu->serdev);
+		ret = qca_power_setup(hu, true);
+		if (ret)
+			return ret;
+
+		ret = serdev_device_open(hu->serdev);
+		if (ret) {
+			bt_dev_err(hu->hdev, "failed to open port");
+			return ret;
+		}
+	}
+
 	/* Forcefully enable wcn3990 to enter in to boot mode. */
 	host_set_baudrate(hu, 2400);
 	ret = qca_send_power_pulse(hdev, QCA_WCN3990_POWEROFF_PULSE);
@@ -1152,6 +1171,12 @@ static int qca_setup(struct hci_uart *hu)
 
 	if (qcadev->btsoc_type == QCA_WCN3990) {
 		bt_dev_info(hdev, "setting up wcn3990");
+
+		/* Enable NON_PERSISTENT_SETUP QUIRK to ensure to execute
+		 * setup for every hci up.
+		 */
+		set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
+		hu->hdev->shutdown = qca_power_off;
 		ret = qca_wcn3990_init(hu);
 		if (ret)
 			return ret;
@@ -1242,6 +1267,14 @@ static void qca_power_shutdown(struct hci_uart *hu)
 	qca_power_setup(hu, false);
 }
 
+static int qca_power_off(struct hci_dev *hdev)
+{
+	struct hci_uart *hu = hci_get_drvdata(hdev);
+
+	qca_power_shutdown(hu);
+	return 0;
+}
+
 static int qca_enable_regulator(struct qca_vreg vregs,
 				struct regulator *regulator)
 {