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 */
nfc_hci_hcp_message_tx(struct nfc_hci_dev * hdev,u8 pipe,u8 type,u8 instruction,const u8 * payload,size_t payload_len,data_exchange_cb_t cb,void * cb_context,unsigned long completion_delay)33 int 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
120 out_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 */
nfc_hci_hcp_message_rx(struct nfc_hci_dev * hdev,u8 pipe,u8 type,u8 instruction,struct sk_buff * skb)131 void 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
