NFC: HCI support
This is an implementation of ETSI TS 102 622 specification.
Many NFC chipsets use HCI as the host <-> target protocol on top of a
serial link like i2c.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/nfc/hci/hcp.c b/net/nfc/hci/hcp.c
new file mode 100644
index 0000000..7212cf2
--- /dev/null
+++ b/net/nfc/hci/hcp.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2012 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#define pr_fmt(fmt) "hci: %s: " fmt, __func__
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <net/nfc/hci.h>
+
+#include "hci.h"
+
+/*
+ * Payload is the HCP message data only. Instruction will be prepended.
+ * Guarantees that cb will be called upon completion or timeout delay
+ * counted from the moment the cmd is sent to the transport.
+ */
+int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
+ u8 type, u8 instruction,
+ const u8 *payload, size_t payload_len,
+ hci_cmd_cb_t cb, void *cb_data,
+ unsigned long completion_delay)
+{
+ struct nfc_dev *ndev = hdev->ndev;
+ struct hci_msg *cmd;
+ const u8 *ptr = payload;
+ int hci_len, err;
+ bool firstfrag = true;
+
+ cmd = kzalloc(sizeof(struct hci_msg), GFP_KERNEL);
+ if (cmd == NULL)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&cmd->msg_l);
+ skb_queue_head_init(&cmd->msg_frags);
+ cmd->wait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;
+ cmd->cb = cb;
+ cmd->cb_context = cb_data;
+ cmd->completion_delay = completion_delay;
+
+ hci_len = payload_len + 1;
+ while (hci_len > 0) {
+ struct sk_buff *skb;
+ int skb_len, data_link_len;
+ struct hcp_packet *packet;
+
+ if (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len <=
+ hdev->max_data_link_payload)
+ data_link_len = hci_len;
+ else
+ data_link_len = hdev->max_data_link_payload -
+ NFC_HCI_HCP_PACKET_HEADER_LEN;
+
+ skb_len = ndev->tx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +
+ data_link_len + ndev->tx_tailroom;
+ hci_len -= data_link_len;
+
+ skb = alloc_skb(skb_len, GFP_KERNEL);
+ if (skb == NULL) {
+ err = -ENOMEM;
+ goto out_skb_err;
+ }
+ skb_reserve(skb, ndev->tx_headroom);
+
+ skb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);
+
+ /* Only the last fragment will have the cb bit set to 1 */
+ packet = (struct hcp_packet *)skb->data;
+ packet->header = pipe;
+ if (firstfrag) {
+ firstfrag = false;
+ packet->message.header = HCP_HEADER(type, instruction);
+ if (ptr) {
+ memcpy(packet->message.data, ptr,
+ data_link_len - 1);
+ ptr += data_link_len - 1;
+ }
+ } else {
+ memcpy(&packet->message, ptr, data_link_len);
+ ptr += data_link_len;
+ }
+
+ /* This is the last fragment, set the cb bit */
+ if (hci_len == 0)
+ packet->header |= ~NFC_HCI_FRAGMENT;
+
+ skb_queue_tail(&cmd->msg_frags, skb);
+ }
+
+ mutex_lock(&hdev->msg_tx_mutex);
+ list_add_tail(&hdev->msg_tx_queue, &cmd->msg_l);
+ mutex_unlock(&hdev->msg_tx_mutex);
+
+ queue_work(hdev->msg_tx_wq, &hdev->msg_tx_work);
+
+ return 0;
+
+out_skb_err:
+ skb_queue_purge(&cmd->msg_frags);
+ kfree(cmd);
+
+ return err;
+}
+
+u8 nfc_hci_pipe2gate(struct nfc_hci_dev *hdev, u8 pipe)
+{
+ int gate;
+
+ for (gate = 0; gate < NFC_HCI_MAX_GATES; gate++)
+ if (hdev->gate2pipe[gate] == pipe)
+ return gate;
+
+ return 0xff;
+}
+
+/*
+ * Receive hcp message for pipe, with type and cmd.
+ * skb contains optional message data only.
+ */
+void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
+ u8 instruction, struct sk_buff *skb)
+{
+ switch (type) {
+ case NFC_HCI_HCP_RESPONSE:
+ nfc_hci_resp_received(hdev, instruction, skb);
+ break;
+ case NFC_HCI_HCP_COMMAND:
+ nfc_hci_cmd_received(hdev, pipe, instruction, skb);
+ break;
+ case NFC_HCI_HCP_EVENT:
+ nfc_hci_event_received(hdev, pipe, instruction, skb);
+ break;
+ default:
+ pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
+ type, instruction);
+ kfree_skb(skb);
+ break;
+ }
+}