xref: /openbmc/linux/net/nfc/hci/hcp.c (revision 9429ec96)
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, write to the
16  * Free Software Foundation, Inc.,
17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18  */
19 
20 #define pr_fmt(fmt) "hci: %s: " fmt, __func__
21 
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 
26 #include <net/nfc/hci.h>
27 
28 #include "hci.h"
29 
30 /*
31  * Payload is the HCP message data only. Instruction will be prepended.
32  * Guarantees that cb will be called upon completion or timeout delay
33  * counted from the moment the cmd is sent to the transport.
34  */
35 int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
36 			   u8 type, u8 instruction,
37 			   const u8 *payload, size_t payload_len,
38 			   hci_cmd_cb_t cb, void *cb_data,
39 			   unsigned long completion_delay)
40 {
41 	struct nfc_dev *ndev = hdev->ndev;
42 	struct hci_msg *cmd;
43 	const u8 *ptr = payload;
44 	int hci_len, err;
45 	bool firstfrag = true;
46 
47 	cmd = kzalloc(sizeof(struct hci_msg), GFP_KERNEL);
48 	if (cmd == NULL)
49 		return -ENOMEM;
50 
51 	INIT_LIST_HEAD(&cmd->msg_l);
52 	skb_queue_head_init(&cmd->msg_frags);
53 	cmd->wait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;
54 	cmd->cb = cb;
55 	cmd->cb_context = cb_data;
56 	cmd->completion_delay = completion_delay;
57 
58 	hci_len = payload_len + 1;
59 	while (hci_len > 0) {
60 		struct sk_buff *skb;
61 		int skb_len, data_link_len;
62 		struct hcp_packet *packet;
63 
64 		if (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len <=
65 		    hdev->max_data_link_payload)
66 			data_link_len = hci_len;
67 		else
68 			data_link_len = hdev->max_data_link_payload -
69 					NFC_HCI_HCP_PACKET_HEADER_LEN;
70 
71 		skb_len = ndev->tx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +
72 			  data_link_len + ndev->tx_tailroom;
73 		hci_len -= data_link_len;
74 
75 		skb = alloc_skb(skb_len, GFP_KERNEL);
76 		if (skb == NULL) {
77 			err = -ENOMEM;
78 			goto out_skb_err;
79 		}
80 		skb_reserve(skb, ndev->tx_headroom);
81 
82 		skb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);
83 
84 		/* Only the last fragment will have the cb bit set to 1 */
85 		packet = (struct hcp_packet *)skb->data;
86 		packet->header = pipe;
87 		if (firstfrag) {
88 			firstfrag = false;
89 			packet->message.header = HCP_HEADER(type, instruction);
90 			if (ptr) {
91 				memcpy(packet->message.data, ptr,
92 				       data_link_len - 1);
93 				ptr += data_link_len - 1;
94 			}
95 		} else {
96 			memcpy(&packet->message, ptr, data_link_len);
97 			ptr += data_link_len;
98 		}
99 
100 		/* This is the last fragment, set the cb bit */
101 		if (hci_len == 0)
102 			packet->header |= ~NFC_HCI_FRAGMENT;
103 
104 		skb_queue_tail(&cmd->msg_frags, skb);
105 	}
106 
107 	mutex_lock(&hdev->msg_tx_mutex);
108 	list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
109 	mutex_unlock(&hdev->msg_tx_mutex);
110 
111 	queue_work(hdev->msg_tx_wq, &hdev->msg_tx_work);
112 
113 	return 0;
114 
115 out_skb_err:
116 	skb_queue_purge(&cmd->msg_frags);
117 	kfree(cmd);
118 
119 	return err;
120 }
121 
122 u8 nfc_hci_pipe2gate(struct nfc_hci_dev *hdev, u8 pipe)
123 {
124 	int gate;
125 
126 	for (gate = 0; gate < NFC_HCI_MAX_GATES; gate++)
127 		if (hdev->gate2pipe[gate] == pipe)
128 			return gate;
129 
130 	return 0xff;
131 }
132 
133 /*
134  * Receive hcp message for pipe, with type and cmd.
135  * skb contains optional message data only.
136  */
137 void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
138 			    u8 instruction, struct sk_buff *skb)
139 {
140 	switch (type) {
141 	case NFC_HCI_HCP_RESPONSE:
142 		nfc_hci_resp_received(hdev, instruction, skb);
143 		break;
144 	case NFC_HCI_HCP_COMMAND:
145 		nfc_hci_cmd_received(hdev, pipe, instruction, skb);
146 		break;
147 	case NFC_HCI_HCP_EVENT:
148 		nfc_hci_event_received(hdev, pipe, instruction, skb);
149 		break;
150 	default:
151 		pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
152 		       type, instruction);
153 		kfree_skb(skb);
154 		break;
155 	}
156 }
157