aboutsummaryrefslogtreecommitdiff
path: root/drivers/nfc/mei_phy.c
blob: 85f90090cc1d1e167de6391e3481b597451555bd (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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
/*
 * MEI Library for mei bus nfc device access
 *
 * Copyright (C) 2013  Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * 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) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/nfc.h>

#include "mei_phy.h"

struct mei_nfc_hdr {
	u8 cmd;
	u8 status;
	u16 req_id;
	u32 reserved;
	u16 data_size;
} __packed;

#define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD)

#define MEI_DUMP_SKB_IN(info, skb)				\
do {								\
	pr_debug("%s:\n", info);				\
	print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET,	\
			16, 1, (skb)->data, (skb)->len, false);	\
} while (0)

#define MEI_DUMP_SKB_OUT(info, skb)				\
do {								\
	pr_debug("%s:\n", info);				\
	print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET,	\
		       16, 1, (skb)->data, (skb)->len, false);	\
} while (0)

int nfc_mei_phy_enable(void *phy_id)
{
	int r;
	struct nfc_mei_phy *phy = phy_id;

	pr_info("%s\n", __func__);

	if (phy->powered == 1)
		return 0;

	r = mei_cl_enable_device(phy->device);
	if (r < 0) {
		pr_err("Could not enable device\n");
		return r;
	}

	r = mei_cl_register_event_cb(phy->device, nfc_mei_event_cb, phy);
	if (r) {
		pr_err("Event cb registration failed\n");
		mei_cl_disable_device(phy->device);
		phy->powered = 0;

		return r;
	}

	phy->powered = 1;

	return 0;
}
EXPORT_SYMBOL_GPL(nfc_mei_phy_enable);

void nfc_mei_phy_disable(void *phy_id)
{
	struct nfc_mei_phy *phy = phy_id;

	pr_info("%s\n", __func__);

	mei_cl_disable_device(phy->device);

	phy->powered = 0;
}
EXPORT_SYMBOL_GPL(nfc_mei_phy_disable);

/*
 * Writing a frame must not return the number of written bytes.
 * It must return either zero for success, or <0 for error.
 * In addition, it must not alter the skb
 */
static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb)
{
	struct nfc_mei_phy *phy = phy_id;
	int r;

	MEI_DUMP_SKB_OUT("mei frame sent", skb);

	r = mei_cl_send(phy->device, skb->data, skb->len);
	if (r > 0)
		r = 0;

	return r;
}

void nfc_mei_event_cb(struct mei_cl_device *device, u32 events, void *context)
{
	struct nfc_mei_phy *phy = context;

	if (phy->hard_fault != 0)
		return;

	if (events & BIT(MEI_CL_EVENT_RX)) {
		struct sk_buff *skb;
		int reply_size;

		skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
		if (!skb)
			return;

		reply_size = mei_cl_recv(device, skb->data, MEI_NFC_MAX_READ);
		if (reply_size < MEI_NFC_HEADER_SIZE) {
			kfree(skb);
			return;
		}

		skb_put(skb, reply_size);
		skb_pull(skb, MEI_NFC_HEADER_SIZE);

		MEI_DUMP_SKB_IN("mei frame read", skb);

		nfc_hci_recv_frame(phy->hdev, skb);
	}
}
EXPORT_SYMBOL_GPL(nfc_mei_event_cb);

struct nfc_phy_ops mei_phy_ops = {
	.write = nfc_mei_phy_write,
	.enable = nfc_mei_phy_enable,
	.disable = nfc_mei_phy_disable,
};
EXPORT_SYMBOL_GPL(mei_phy_ops);

struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *device)
{
	struct nfc_mei_phy *phy;

	phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
	if (!phy)
		return NULL;

	phy->device = device;
	mei_cl_set_drvdata(device, phy);

	return phy;
}
EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);

void nfc_mei_phy_free(struct nfc_mei_phy *phy)
{
	kfree(phy);
}
EXPORT_SYMBOL_GPL(nfc_mei_phy_free);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("mei bus NFC device interface");