1/*
2 * Copyright (C) 2012  Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
16 */
17
18#define pr_fmt(fmt) "hci: %s: " fmt, __func__
19
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23
24#include <net/nfc/hci.h>
25
26#include "hci.h"
27
28/*
29 * Payload is the HCP message data only. Instruction will be prepended.
30 * Guarantees that cb will be called upon completion or timeout delay
31 * counted from the moment the cmd is sent to the transport.
32 */
33int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
34			   u8 type, u8 instruction,
35			   const u8 *payload, size_t payload_len,
36			   data_exchange_cb_t cb, void *cb_context,
37			   unsigned long completion_delay)
38{
39	struct nfc_dev *ndev = hdev->ndev;
40	struct hci_msg *cmd;
41	const u8 *ptr = payload;
42	int hci_len, err;
43	bool firstfrag = true;
44
45	cmd = kzalloc(sizeof(struct hci_msg), GFP_KERNEL);
46	if (cmd == NULL)
47		return -ENOMEM;
48
49	INIT_LIST_HEAD(&cmd->msg_l);
50	skb_queue_head_init(&cmd->msg_frags);
51	cmd->wait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;
52	cmd->cb = cb;
53	cmd->cb_context = cb_context;
54	cmd->completion_delay = completion_delay;
55
56	hci_len = payload_len + 1;
57	while (hci_len > 0) {
58		struct sk_buff *skb;
59		int skb_len, data_link_len;
60		struct hcp_packet *packet;
61
62		if (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len <=
63		    hdev->max_data_link_payload)
64			data_link_len = hci_len;
65		else
66			data_link_len = hdev->max_data_link_payload -
67					NFC_HCI_HCP_PACKET_HEADER_LEN;
68
69		skb_len = ndev->tx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +
70			  data_link_len + ndev->tx_tailroom;
71		hci_len -= data_link_len;
72
73		skb = alloc_skb(skb_len, GFP_KERNEL);
74		if (skb == NULL) {
75			err = -ENOMEM;
76			goto out_skb_err;
77		}
78		skb_reserve(skb, ndev->tx_headroom);
79
80		skb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);
81
82		/* Only the last fragment will have the cb bit set to 1 */
83		packet = (struct hcp_packet *)skb->data;
84		packet->header = pipe;
85		if (firstfrag) {
86			firstfrag = false;
87			packet->message.header = HCP_HEADER(type, instruction);
88			if (ptr) {
89				memcpy(packet->message.data, ptr,
90				       data_link_len - 1);
91				ptr += data_link_len - 1;
92			}
93		} else {
94			memcpy(&packet->message, ptr, data_link_len);
95			ptr += data_link_len;
96		}
97
98		/* This is the last fragment, set the cb bit */
99		if (hci_len == 0)
100			packet->header |= ~NFC_HCI_FRAGMENT;
101
102		skb_queue_tail(&cmd->msg_frags, skb);
103	}
104
105	mutex_lock(&hdev->msg_tx_mutex);
106
107	if (hdev->shutting_down) {
108		err = -ESHUTDOWN;
109		mutex_unlock(&hdev->msg_tx_mutex);
110		goto out_skb_err;
111	}
112
113	list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
114	mutex_unlock(&hdev->msg_tx_mutex);
115
116	schedule_work(&hdev->msg_tx_work);
117
118	return 0;
119
120out_skb_err:
121	skb_queue_purge(&cmd->msg_frags);
122	kfree(cmd);
123
124	return err;
125}
126
127/*
128 * Receive hcp message for pipe, with type and cmd.
129 * skb contains optional message data only.
130 */
131void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
132			    u8 instruction, struct sk_buff *skb)
133{
134	switch (type) {
135	case NFC_HCI_HCP_RESPONSE:
136		nfc_hci_resp_received(hdev, instruction, skb);
137		break;
138	case NFC_HCI_HCP_COMMAND:
139		nfc_hci_cmd_received(hdev, pipe, instruction, skb);
140		break;
141	case NFC_HCI_HCP_EVENT:
142		nfc_hci_event_received(hdev, pipe, instruction, skb);
143		break;
144	default:
145		pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
146		       type, instruction);
147		kfree_skb(skb);
148		break;
149	}
150}
151