[PATCH v4] bluetooth: hci_qca: Fix qca6390 enable failure after warm reboot

[Zijun Hu]

Warm reboot can not restore qca6390 controller baudrate
to default due to lack of controllable BT_EN pin or power
supply, so fails to download firmware after warm reboot.

Fixed by sending EDL_SOC_RESET VSC to reset controller
within added device shutdown implementation.

Signed-off-by: Zijun Hu <zijuhu@xxxxxxxxxxxxxx>
---
 drivers/bluetooth/hci_qca.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index e4a6823..8e03bfe 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -1975,6 +1975,38 @@ static void qca_serdev_remove(struct serdev_device *serdev)
 	hci_uart_unregister_device(&qcadev->serdev_hu);
 }
 
+static void qca_serdev_shutdown(struct device *dev)
+{
+	int ret;
+	int timeout = msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS);
+	struct serdev_device *serdev = to_serdev_device(dev);
+	struct qca_serdev *qcadev = serdev_device_get_drvdata(serdev);
+	const u8 ibs_wake_cmd[] = { 0xFD };
+	const u8 edl_reset_soc_cmd[] = { 0x01, 0x00, 0xFC, 0x01, 0x05 };
+
+	if (qcadev->btsoc_type == QCA_QCA6390) {
+		serdev_device_write_flush(serdev);
+		ret = serdev_device_write_buf(serdev,
+				ibs_wake_cmd, sizeof(ibs_wake_cmd));
+		if (ret < 0) {
+			BT_ERR("QCA send IBS_WAKE_IND error: %d", ret);
+			return;
+		}
+		serdev_device_wait_until_sent(serdev, timeout);
+		usleep_range(8000, 10000);
+
+		serdev_device_write_flush(serdev);
+		ret = serdev_device_write_buf(serdev,
+				edl_reset_soc_cmd, sizeof(edl_reset_soc_cmd));
+		if (ret < 0) {
+			BT_ERR("QCA send EDL_RESET_REQ error: %d", ret);
+			return;
+		}
+		serdev_device_wait_until_sent(serdev, timeout);
+		usleep_range(8000, 10000);
+	}
+}
+
 static int __maybe_unused qca_suspend(struct device *dev)
 {
 	struct hci_dev *hdev = container_of(dev, struct hci_dev, dev);
@@ -2100,6 +2132,7 @@ static struct serdev_device_driver qca_serdev_driver = {
 		.name = "hci_uart_qca",
 		.of_match_table = of_match_ptr(qca_bluetooth_of_match),
 		.acpi_match_table = ACPI_PTR(qca_bluetooth_acpi_match),
+		.shutdown = qca_serdev_shutdown,
 		.pm = &qca_pm_ops,
 	},
 };
-- 
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