path: root/net/nfc/hci/core.c

/*
 * 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 <linux/nfc.h>

#include <net/nfc/nfc.h>
#include <net/nfc/hci.h>
#include <net/nfc/llc.h>

#include "hci.h"

/* Largest headroom needed for outgoing HCI commands */
#define HCI_CMDS_HEADROOM 1

int nfc_hci_result_to_errno(u8 result)
{
	switch (result) {
	case NFC_HCI_ANY_OK:
		return 0;
	case NFC_HCI_ANY_E_REG_PAR_UNKNOWN:
		return -EOPNOTSUPP;
	case NFC_HCI_ANY_E_TIMEOUT:
		return -ETIME;
	default:
		return -1;
	}
}
EXPORT_SYMBOL(nfc_hci_result_to_errno);

static void nfc_hci_msg_tx_work(struct work_struct *work)
{
	struct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,
						msg_tx_work);
	struct hci_msg *msg;
	struct sk_buff *skb;
	int r = 0;

	mutex_lock(&hdev->msg_tx_mutex);
	if (hdev->shutting_down)
		goto exit;

	if (hdev->cmd_pending_msg) {
		if (timer_pending(&hdev->cmd_timer) == 0) {
			if (hdev->cmd_pending_msg->cb)
				hdev->cmd_pending_msg->cb(hdev->
							  cmd_pending_msg->
							  cb_context,
							  NULL,
							  -ETIME);
			kfree(hdev->cmd_pending_msg);
			hdev->cmd_pending_msg = NULL;
		} else {
			goto exit;
		}
	}

next_msg:
	if (list_empty(&hdev->msg_tx_queue))
		goto exit;

	msg = list_first_entry(&hdev->msg_tx_queue, struct hci_msg, msg_l);
	list_del(&msg->msg_l);

	pr_debug("msg_tx_queue has a cmd to send\n");
	while ((skb = skb_dequeue(&msg->msg_frags)) != NULL) {
		r = nfc_llc_xmit_from_hci(hdev->llc, skb);
		if (r < 0) {
			kfree_skb(skb);
			skb_queue_purge(&msg->msg_frags);
			if (msg->cb)
				msg->cb(msg->cb_context, NULL, r);
			kfree(msg);
			break;
		}
	}

	if (r)
		goto next_msg;

	if (msg->wait_response == false) {
		kfree(msg);
		goto next_msg;
	}

	hdev->cmd_pending_msg = msg;
	mod_timer(&hdev->cmd_timer, jiffies +
		  msecs_to_jiffies(hdev->cmd_pending_msg->completion_delay));

exit:
	mutex_unlock(&hdev->msg_tx_mutex);
}

static void nfc_hci_msg_rx_work(struct work_struct *work)
{
	struct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,
						msg_rx_work);
	struct sk_buff *skb;
	struct hcp_message *message;
	u8 pipe;
	u8 type;
	u8 instruction;

	while ((skb = skb_dequeue(&hdev->msg_rx_queue)) != NULL) {
		pipe = skb->data[0];
		skb_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN);
		message = (struct hcp_message *)skb->data;
		type = HCP_MSG_GET_TYPE(message->header);
		instruction = HCP_MSG_GET_CMD(message->header);
		skb_pull(skb, NFC_HCI_HCP_MESSAGE_HEADER_LEN);

		nfc_hci_hcp_message_rx(hdev, pipe, type, instruction, skb);
	}
}

static void __nfc_hci_cmd_completion(struct nfc_hci_dev *hdev, int err,
				     struct sk_buff *skb)
{
	del_timer_sync(&hdev->cmd_timer);

	if (hdev->cmd_pending_msg->cb)
		hdev->cmd_pending_msg->cb(hdev->cmd_pending_msg->cb_context,
					  skb, err);
	else
		kfree_skb(skb);

	kfree(hdev->cmd_pending_msg);
	hdev->cmd_pending_msg = NULL;

	schedule_work(&hdev->msg_tx_work);
}

void nfc_hci_resp_received(struct nfc_hci_dev *hdev, u8 result,
			   struct sk_buff *skb)
{
	mutex_lock(&hdev->msg_tx_mutex);

	if (hdev->cmd_pending_msg == NULL) {
		kfree_skb(skb);
		goto exit;
	}

	__nfc_hci_cmd_completion(hdev, nfc_hci_result_to_errno(result), skb);

exit:
	mutex_unlock(&hdev->msg_tx_mutex);
}

void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
			  struct sk_buff