NFC: hci: Add stop_poll HCI operand.

stop_poll allows to stop CLF reader polling. Some other operations might be
necessary for some CLF to stop polling. For example in card mode.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/net/nfc/hci.h

@@ -37,6 +37,7 @@ struct nfc_hci_ops {
 	int (*xmit) (struct nfc_hci_dev *hdev, struct sk_buff *skb);
 	int (*start_poll) (struct nfc_hci_dev *hdev,
 			   u32 im_protocols, u32 tm_protocols);
+	void (*stop_poll) (struct nfc_hci_dev *hdev);
 	int (*dep_link_up)(struct nfc_hci_dev *hdev, struct nfc_target *target,
 			   u8 comm_mode, u8 *gb, size_t gb_len);
 	int (*dep_link_down)(struct nfc_hci_dev *hdev);

net/nfc/hci/core.c

@@ -553,8 +553,11 @@ static void hci_stop_poll(struct nfc_dev *nfc_dev)
 {
 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
 
-	nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
-			   NFC_HCI_EVT_END_OPERATION, NULL, 0);
+	if (hdev->ops->stop_poll)
+		hdev->ops->stop_poll(hdev);
+	else
+		nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
+				   NFC_HCI_EVT_END_OPERATION, NULL, 0);
 }
 
 static int hci_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,