+#ifdef CONFIG_PM
+static int intel_wait_lpm_transaction(struct hci_uart *hu)
+{
+ struct intel_data *intel = hu->priv;
+ int err;
+
+ err = wait_on_bit_timeout(&intel->flags, STATE_LPM_TRANSACTION,
+ TASK_INTERRUPTIBLE,
+ msecs_to_jiffies(1000));
+
+ if (err == 1) {
+ bt_dev_err(hu->hdev, "LPM transaction interrupted");
+ return -EINTR;
+ }
+
+ if (err) {
+ bt_dev_err(hu->hdev, "LPM transaction timeout");
+ return -ETIMEDOUT;
+ }
+
+ return err;
+}
+
+static int intel_lpm_suspend(struct hci_uart *hu)
+{
+ static const u8 suspend[] = { 0x01, 0x01, 0x01 };
+ struct intel_data *intel = hu->priv;
+ struct sk_buff *skb;
+
+ if (!test_bit(STATE_LPM_ENABLED, &intel->flags) ||
+ test_bit(STATE_SUSPENDED, &intel->flags))
+ return 0;
+
+ if (test_bit(STATE_TX_ACTIVE, &intel->flags))
+ return -EAGAIN;
+
+ bt_dev_dbg(hu->hdev, "Suspending");
+
+ skb = bt_skb_alloc(sizeof(suspend), GFP_KERNEL);
+ if (!skb) {
+ bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
+ return -ENOMEM;
+ }
+
+ memcpy(skb_put(skb, sizeof(suspend)), suspend, sizeof(suspend));
+ bt_cb(skb)->pkt_type = HCI_LPM_PKT;
+
+ set_bit(STATE_LPM_TRANSACTION, &intel->flags);
+
+ /* LPM flow is a priority, enqueue packet at list head */
+ skb_queue_head(&intel->txq, skb);
+ hci_uart_tx_wakeup(hu);
+
+ intel_wait_lpm_transaction(hu);
+ /* Even in case of failure, continue and test the suspended flag */
+
+ clear_bit(STATE_LPM_TRANSACTION, &intel->flags);
+
+ if (!test_bit(STATE_SUSPENDED, &intel->flags)) {
+ bt_dev_err(hu->hdev, "Device suspend error");
+ return -EINVAL;
+ }
+
+ bt_dev_dbg(hu->hdev, "Suspended");
+
+ hci_uart_set_flow_control(hu, true);
+
+ return 0;
+}
+
+static int intel_lpm_resume(struct hci_uart *hu)
+{
+ struct intel_data *intel = hu->priv;
+ struct sk_buff *skb;
+
+ if (!test_bit(STATE_LPM_ENABLED, &intel->flags) ||
+ !test_bit(STATE_SUSPENDED, &intel->flags))
+ return 0;
+
+ bt_dev_dbg(hu->hdev, "Resuming");
+
+ hci_uart_set_flow_control(hu, false);
+
+ skb = bt_skb_alloc(0, GFP_KERNEL);
+ if (!skb) {
+ bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
+ return -ENOMEM;
+ }
+
+ bt_cb(skb)->pkt_type = HCI_LPM_WAKE_PKT;
+
+ set_bit(STATE_LPM_TRANSACTION, &intel->flags);
+
+ /* LPM flow is a priority, enqueue packet at list head */
+ skb_queue_head(&intel->txq, skb);
+ hci_uart_tx_wakeup(hu);
+
+ intel_wait_lpm_transaction(hu);
+ /* Even in case of failure, continue and test the suspended flag */
+
+ clear_bit(STATE_LPM_TRANSACTION, &intel->flags);
+
+ if (test_bit(STATE_SUSPENDED, &intel->flags)) {
+ bt_dev_err(hu->hdev, "Device resume error");
+ return -EINVAL;
+ }
+
+ bt_dev_dbg(hu->hdev, "Resumed");
+
+ return 0;
+}
+#endif /* CONFIG_PM */
+
+static int intel_lpm_host_wake(struct hci_uart *hu)
+{
+ static const u8 lpm_resume_ack[] = { LPM_OP_RESUME_ACK, 0x00 };
+ struct intel_data *intel = hu->priv;
+ struct sk_buff *skb;
+
+ hci_uart_set_flow_control(hu, false);
+
+ clear_bit(STATE_SUSPENDED, &intel->flags);
+
+ skb = bt_skb_alloc(sizeof(lpm_resume_ack), GFP_KERNEL);
+ if (!skb) {
+ bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
+ return -ENOMEM;
+ }
+
+ memcpy(skb_put(skb, sizeof(lpm_resume_ack)), lpm_resume_ack,
+ sizeof(lpm_resume_ack));
+ bt_cb(skb)->pkt_type = HCI_LPM_PKT;
+
+ /* LPM flow is a priority, enqueue packet at list head */
+ skb_queue_head(&intel->txq, skb);
+ hci_uart_tx_wakeup(hu);
+
+ bt_dev_dbg(hu->hdev, "Resumed by controller");
+
+ return 0;
+}
+
+static irqreturn_t intel_irq(int irq, void *dev_id)
+{
+ struct intel_device *idev = dev_id;
+
+ dev_info(&idev->pdev->dev, "hci_intel irq\n");
+
+ mutex_lock(&idev->hu_lock);
+ if (idev->hu)
+ intel_lpm_host_wake(idev->hu);
+ mutex_unlock(&idev->hu_lock);
+
+ /* Host/Controller are now LPM resumed, trigger a new delayed suspend */
+ pm_runtime_get(&idev->pdev->dev);
+ pm_runtime_mark_last_busy(&idev->pdev->dev);
+ pm_runtime_put_autosuspend(&idev->pdev->dev);
+
+ return IRQ_HANDLED;
+}
+