NFC: st21nfca: Add HCI transaction event support

The transaction notifies the host (DH) that an action
is required to manage a specific Secure Element application.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/st21nfca/st21nfca_se.c

@@ -301,6 +301,8 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
 				u8 event, struct sk_buff *skb)
 {
 	int r = 0;
+	struct device *dev = &hdev->ndev->dev;
+	struct nfc_evt_transaction *transaction;
 
 	pr_debug("connectivity gate event: %x\n", event);
 
@@ -308,6 +310,25 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
 	case ST21NFCA_EVT_CONNECTIVITY:
 		break;
 	case ST21NFCA_EVT_TRANSACTION:
+		if (skb->len < NFC_MIN_AID_LENGTH + 2 &&
+		    skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
+			return -EPROTO;
+
+		transaction = (struct nfc_evt_transaction *)devm_kzalloc(dev,
+						   skb->len - 2, GFP_KERNEL);
+
+		transaction->aid_len = skb->data[1];
+		memcpy(transaction->aid, &skb->data[2], skb->data[1]);
+
+		if (skb->data[transaction->aid_len + 2] !=
+		    NFC_EVT_TRANSACTION_PARAMS_TAG)
+			return -EPROTO;
+
+		transaction->params_len = skb->data[transaction->aid_len + 3];
+		memcpy(transaction->params, skb->data +
+		       transaction->aid_len + 4, transaction->params_len);
+
+		r = nfc_se_transaction(hdev->ndev, host, transaction);
 		break;
 	default:
 		return 1;