2 * HCI based Driver for Inside Secure microread NFC Chip
4 * Copyright (C) 2013 Intel Corporation. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the
17 * Free Software Foundation, Inc.,
18 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/gpio.h>
25 #include <linux/mei_cl_bus.h>
27 #include <linux/nfc.h>
28 #include <net/nfc/hci.h>
29 #include <net/nfc/llc.h>
31 #include "microread.h"
33 #define MICROREAD_DRIVER_NAME "microread"
41 } __attribute__((packed));
43 #define MEI_NFC_HEADER_SIZE 10
44 #define MEI_NFC_MAX_HCI_PAYLOAD 300
45 #define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD)
47 struct microread_mei_phy {
48 struct mei_cl_device *device;
49 struct nfc_hci_dev *hdev;
54 * < 0 if hardware error occured (e.g. i2c err)
55 * and prevents normal operation.
59 #define MEI_DUMP_SKB_IN(info, skb) \
61 pr_debug("%s:\n", info); \
62 print_hex_dump(KERN_DEBUG, "mei in : ", DUMP_PREFIX_OFFSET, \
63 16, 1, (skb)->data, (skb)->len, 0); \
66 #define MEI_DUMP_SKB_OUT(info, skb) \
68 pr_debug("%s:\n", info); \
69 print_hex_dump(KERN_DEBUG, "mei out: ", DUMP_PREFIX_OFFSET, \
70 16, 1, (skb)->data, (skb)->len, 0); \
73 static int microread_mei_enable(void *phy_id)
75 struct microread_mei_phy *phy = phy_id;
77 pr_info(DRIVER_DESC ": %s\n", __func__);
84 static void microread_mei_disable(void *phy_id)
86 struct microread_mei_phy *phy = phy_id;
88 pr_info(DRIVER_DESC ": %s\n", __func__);
94 * Writing a frame must not return the number of written bytes.
95 * It must return either zero for success, or <0 for error.
96 * In addition, it must not alter the skb
98 static int microread_mei_write(void *phy_id, struct sk_buff *skb)
100 struct microread_mei_phy *phy = phy_id;
103 MEI_DUMP_SKB_OUT("mei frame sent", skb);
105 r = mei_cl_send(phy->device, skb->data, skb->len);
112 static void microread_event_cb(struct mei_cl_device *device, u32 events,
115 struct microread_mei_phy *phy = context;
117 if (phy->hard_fault != 0)
120 if (events & BIT(MEI_CL_EVENT_RX)) {
124 skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
128 reply_size = mei_cl_recv(device, skb->data, MEI_NFC_MAX_READ);
129 if (reply_size < MEI_NFC_HEADER_SIZE) {
134 skb_put(skb, reply_size);
135 skb_pull(skb, MEI_NFC_HEADER_SIZE);
137 MEI_DUMP_SKB_IN("mei frame read", skb);
139 nfc_hci_recv_frame(phy->hdev, skb);
143 static struct nfc_phy_ops mei_phy_ops = {
144 .write = microread_mei_write,
145 .enable = microread_mei_enable,
146 .disable = microread_mei_disable,
149 static int microread_mei_probe(struct mei_cl_device *device,
150 const struct mei_cl_device_id *id)
152 struct microread_mei_phy *phy;
155 pr_info("Probing NFC microread\n");
157 phy = kzalloc(sizeof(struct microread_mei_phy), GFP_KERNEL);
159 pr_err("Cannot allocate memory for microread mei phy.\n");
163 phy->device = device;
164 mei_cl_set_drvdata(device, phy);
166 r = mei_cl_register_event_cb(device, microread_event_cb, phy);
168 pr_err(MICROREAD_DRIVER_NAME ": event cb registration failed\n");
172 r = microread_probe(phy, &mei_phy_ops, LLC_NOP_NAME,
173 MEI_NFC_HEADER_SIZE, 0, MEI_NFC_MAX_HCI_PAYLOAD,
186 static int microread_mei_remove(struct mei_cl_device *device)
188 struct microread_mei_phy *phy = mei_cl_get_drvdata(device);
190 pr_info("Removing microread\n");
192 microread_remove(phy->hdev);
195 microread_mei_disable(phy);
202 static struct mei_cl_device_id microread_mei_tbl[] = {
203 { MICROREAD_DRIVER_NAME },
205 /* required last entry */
208 MODULE_DEVICE_TABLE(mei, microread_mei_tbl);
210 static struct mei_cl_driver microread_driver = {
211 .id_table = microread_mei_tbl,
212 .name = MICROREAD_DRIVER_NAME,
214 .probe = microread_mei_probe,
215 .remove = microread_mei_remove,
218 static int microread_mei_init(void)
222 pr_debug(DRIVER_DESC ": %s\n", __func__);
224 r = mei_cl_driver_register(µread_driver);
226 pr_err(MICROREAD_DRIVER_NAME ": driver registration failed\n");
233 static void microread_mei_exit(void)
235 mei_cl_driver_unregister(µread_driver);
238 module_init(microread_mei_init);
239 module_exit(microread_mei_exit);
241 MODULE_LICENSE("GPL");
242 MODULE_DESCRIPTION(DRIVER_DESC);