summaryrefslogtreecommitdiffstats
path: root/net/nfc/hci/hcp.c
blob: 4902f5064098168d07076dc7db1502a051f1c722 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2012  Intel Corporation. All rights reserved.
 */

#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,
			   data_exchange_cb_t cb, void *cb_context,
			   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_context;
	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);
		} else {
			packet->message.header = *ptr++;
		}
		if (ptr) {
			memcpy(packet->message.data, ptr, data_link_len - 1);
			ptr += data_link_len - 1;
		}

		/* 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);

	if (hdev->shutting_down) {
		err = -ESHUTDOWN;
		mutex_unlock(&hdev->msg_tx_mutex);
		goto out_skb_err;
	}

	list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
	mutex_unlock(&hdev->msg_tx_mutex);

	schedule_work(&hdev->msg_tx_work);

	return 0;

out_skb_err:
	skb_queue_purge(&cmd->msg_frags);
	kfree(cmd);

	return err;
}

/*
 * 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;
	}
}