1/*
2 * MEI Library for mei bus nfc device access
3 *
4 * Copyright (C) 2013 Intel Corporation. All rights reserved.
5 *
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.
9 *
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.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
17 */
18
19#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21#include <linux/module.h>
22#include <linux/slab.h>
23#include <linux/nfc.h>
24
25#include "mei_phy.h"
26
27struct mei_nfc_hdr {
28 u8 cmd;
29 u8 status;
30 u16 req_id;
31 u32 reserved;
32 u16 data_size;
33} __packed;
34
35struct mei_nfc_cmd {
36 struct mei_nfc_hdr hdr;
37 u8 sub_command;
38 u8 data[];
39} __packed;
40
41struct mei_nfc_reply {
42 struct mei_nfc_hdr hdr;
43 u8 sub_command;
44 u8 reply_status;
45 u8 data[];
46} __packed;
47
48struct mei_nfc_if_version {
49 u8 radio_version_sw[3];
50 u8 reserved[3];
51 u8 radio_version_hw[3];
52 u8 i2c_addr;
53 u8 fw_ivn;
54 u8 vendor_id;
55 u8 radio_type;
56} __packed;
57
58struct mei_nfc_connect {
59 u8 fw_ivn;
60 u8 vendor_id;
61} __packed;
62
63struct mei_nfc_connect_resp {
64 u8 fw_ivn;
65 u8 vendor_id;
66 u16 me_major;
67 u16 me_minor;
68 u16 me_hotfix;
69 u16 me_build;
70} __packed;
71
72
73#define MEI_NFC_CMD_MAINTENANCE 0x00
74#define MEI_NFC_CMD_HCI_SEND 0x01
75#define MEI_NFC_CMD_HCI_RECV 0x02
76
77#define MEI_NFC_SUBCMD_CONNECT 0x00
78#define MEI_NFC_SUBCMD_IF_VERSION 0x01
79
80#define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD)
81
82#define MEI_DUMP_SKB_IN(info, skb) \
83do { \
84 pr_debug("%s:\n", info); \
85 print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET, \
86 16, 1, (skb)->data, (skb)->len, false); \
87} while (0)
88
89#define MEI_DUMP_SKB_OUT(info, skb) \
90do { \
91 pr_debug("%s:\n", info); \
92 print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET, \
93 16, 1, (skb)->data, (skb)->len, false); \
94} while (0)
95
96#define MEI_DUMP_NFC_HDR(info, _hdr) \
97do { \
98 pr_debug("%s:\n", info); \
99 pr_debug("cmd=%02d status=%d req_id=%d rsvd=%d size=%d\n", \
100 (_hdr)->cmd, (_hdr)->status, (_hdr)->req_id, \
101 (_hdr)->reserved, (_hdr)->data_size); \
102} while (0)
103
104static int mei_nfc_if_version(struct nfc_mei_phy *phy)
105{
106
107 struct mei_nfc_cmd cmd;
108 struct mei_nfc_reply *reply = NULL;
109 struct mei_nfc_if_version *version;
110 size_t if_version_length;
111 int bytes_recv, r;
112
113 pr_info("%s\n", __func__);
114
115 memset(&cmd, 0, sizeof(struct mei_nfc_cmd));
116 cmd.hdr.cmd = MEI_NFC_CMD_MAINTENANCE;
117 cmd.hdr.data_size = 1;
118 cmd.sub_command = MEI_NFC_SUBCMD_IF_VERSION;
119
120 MEI_DUMP_NFC_HDR("version", &cmd.hdr);
121 r = mei_cldev_send(phy->cldev, (u8 *)&cmd, sizeof(struct mei_nfc_cmd));
122 if (r < 0) {
123 pr_err("Could not send IF version cmd\n");
124 return r;
125 }
126
127 /* to be sure on the stack we alloc memory */
128 if_version_length = sizeof(struct mei_nfc_reply) +
129 sizeof(struct mei_nfc_if_version);
130
131 reply = kzalloc(if_version_length, GFP_KERNEL);
132 if (!reply)
133 return -ENOMEM;
134
135 bytes_recv = mei_cldev_recv(phy->cldev, (u8 *)reply, if_version_length);
136 if (bytes_recv < 0 || bytes_recv < if_version_length) {
137 pr_err("Could not read IF version\n");
138 r = -EIO;
139 goto err;
140 }
141
142 version = (struct mei_nfc_if_version *)reply->data;
143
144 phy->fw_ivn = version->fw_ivn;
145 phy->vendor_id = version->vendor_id;
146 phy->radio_type = version->radio_type;
147
148err:
149 kfree(reply);
150 return r;
151}
152
153static int mei_nfc_connect(struct nfc_mei_phy *phy)
154{
155 struct mei_nfc_cmd *cmd, *reply;
156 struct mei_nfc_connect *connect;
157 struct mei_nfc_connect_resp *connect_resp;
158 size_t connect_length, connect_resp_length;
159 int bytes_recv, r;
160
161 pr_info("%s\n", __func__);
162
163 connect_length = sizeof(struct mei_nfc_cmd) +
164 sizeof(struct mei_nfc_connect);
165
166 connect_resp_length = sizeof(struct mei_nfc_cmd) +
167 sizeof(struct mei_nfc_connect_resp);
168
169 cmd = kzalloc(connect_length, GFP_KERNEL);
170 if (!cmd)
171 return -ENOMEM;
172 connect = (struct mei_nfc_connect *)cmd->data;
173
174 reply = kzalloc(connect_resp_length, GFP_KERNEL);
175 if (!reply) {
176 kfree(cmd);
177 return -ENOMEM;
178 }
179
180 connect_resp = (struct mei_nfc_connect_resp *)reply->data;
181
182 cmd->hdr.cmd = MEI_NFC_CMD_MAINTENANCE;
183 cmd->hdr.data_size = 3;
184 cmd->sub_command = MEI_NFC_SUBCMD_CONNECT;
185 connect->fw_ivn = phy->fw_ivn;
186 connect->vendor_id = phy->vendor_id;
187
188 MEI_DUMP_NFC_HDR("connect request", &cmd->hdr);
189 r = mei_cldev_send(phy->cldev, (u8 *)cmd, connect_length);
190 if (r < 0) {
191 pr_err("Could not send connect cmd %d\n", r);
192 goto err;
193 }
194
195 bytes_recv = mei_cldev_recv(phy->cldev, (u8 *)reply,
196 connect_resp_length);
197 if (bytes_recv < 0) {
198 r = bytes_recv;
199 pr_err("Could not read connect response %d\n", r);
200 goto err;
201 }
202
203 MEI_DUMP_NFC_HDR("connect reply", &reply->hdr);
204
205 pr_info("IVN 0x%x Vendor ID 0x%x\n",
206 connect_resp->fw_ivn, connect_resp->vendor_id);
207
208 pr_info("ME FW %d.%d.%d.%d\n",
209 connect_resp->me_major, connect_resp->me_minor,
210 connect_resp->me_hotfix, connect_resp->me_build);
211
212 r = 0;
213
214err:
215 kfree(reply);
216 kfree(cmd);
217
218 return r;
219}
220
221static int mei_nfc_send(struct nfc_mei_phy *phy, u8 *buf, size_t length)
222{
223 struct mei_nfc_hdr *hdr;
224 u8 *mei_buf;
225 int err;
226
227 err = -ENOMEM;
228 mei_buf = kzalloc(length + MEI_NFC_HEADER_SIZE, GFP_KERNEL);
229 if (!mei_buf)
230 goto out;
231
232 hdr = (struct mei_nfc_hdr *)mei_buf;
233 hdr->cmd = MEI_NFC_CMD_HCI_SEND;
234 hdr->status = 0;
235 hdr->req_id = phy->req_id;
236 hdr->reserved = 0;
237 hdr->data_size = length;
238
239 MEI_DUMP_NFC_HDR("send", hdr);
240
241 memcpy(mei_buf + MEI_NFC_HEADER_SIZE, buf, length);
242 err = mei_cldev_send(phy->cldev, mei_buf, length + MEI_NFC_HEADER_SIZE);
243 if (err < 0)
244 goto out;
245
246 if (!wait_event_interruptible_timeout(phy->send_wq,
247 phy->recv_req_id == phy->req_id, HZ)) {
248 pr_err("NFC MEI command timeout\n");
249 err = -ETIME;
250 } else {
251 phy->req_id++;
252 }
253out:
254 kfree(mei_buf);
255 return err;
256}
257
258/*
259 * Writing a frame must not return the number of written bytes.
260 * It must return either zero for success, or <0 for error.
261 * In addition, it must not alter the skb
262 */
263static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb)
264{
265 struct nfc_mei_phy *phy = phy_id;
266 int r;
267
268 MEI_DUMP_SKB_OUT("mei frame sent", skb);
269
270 r = mei_nfc_send(phy, skb->data, skb->len);
271 if (r > 0)
272 r = 0;
273
274 return r;
275}
276
277static int mei_nfc_recv(struct nfc_mei_phy *phy, u8 *buf, size_t length)
278{
279 struct mei_nfc_hdr *hdr;
280 int received_length;
281
282 received_length = mei_cldev_recv(phy->cldev, buf, length);
283 if (received_length < 0)
284 return received_length;
285
286 hdr = (struct mei_nfc_hdr *) buf;
287
288 MEI_DUMP_NFC_HDR("receive", hdr);
289 if (hdr->cmd == MEI_NFC_CMD_HCI_SEND) {
290 phy->recv_req_id = hdr->req_id;
291 wake_up(&phy->send_wq);
292
293 return 0;
294 }
295
296 return received_length;
297}
298
299
300static void nfc_mei_rx_cb(struct mei_cl_device *cldev)
301{
302 struct nfc_mei_phy *phy = mei_cldev_get_drvdata(cldev);
303 struct sk_buff *skb;
304 int reply_size;
305
306 if (!phy)
307 return;
308
309 if (phy->hard_fault != 0)
310 return;
311
312 skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
313 if (!skb)
314 return;
315
316 reply_size = mei_nfc_recv(phy, skb->data, MEI_NFC_MAX_READ);
317 if (reply_size < MEI_NFC_HEADER_SIZE) {
318 kfree_skb(skb);
319 return;
320 }
321
322 skb_put(skb, reply_size);
323 skb_pull(skb, MEI_NFC_HEADER_SIZE);
324
325 MEI_DUMP_SKB_IN("mei frame read", skb);
326
327 nfc_hci_recv_frame(phy->hdev, skb);
328}
329
330static int nfc_mei_phy_enable(void *phy_id)
331{
332 int r;
333 struct nfc_mei_phy *phy = phy_id;
334
335 pr_info("%s\n", __func__);
336
337 if (phy->powered == 1)
338 return 0;
339
340 r = mei_cldev_enable(phy->cldev);
341 if (r < 0) {
342 pr_err("Could not enable device %d\n", r);
343 return r;
344 }
345
346 r = mei_nfc_if_version(phy);
347 if (r < 0) {
348 pr_err("Could not enable device %d\n", r);
349 goto err;
350 }
351
352 r = mei_nfc_connect(phy);
353 if (r < 0) {
354 pr_err("Could not connect to device %d\n", r);
355 goto err;
356 }
357
358 r = mei_cldev_register_rx_cb(phy->cldev, nfc_mei_rx_cb);
359 if (r) {
360 pr_err("Event cb registration failed %d\n", r);
361 goto err;
362 }
363
364 phy->powered = 1;
365
366 return 0;
367
368err:
369 phy->powered = 0;
370 mei_cldev_disable(phy->cldev);
371 return r;
372}
373
374static void nfc_mei_phy_disable(void *phy_id)
375{
376 struct nfc_mei_phy *phy = phy_id;
377
378 pr_info("%s\n", __func__);
379
380 mei_cldev_disable(phy->cldev);
381
382 phy->powered = 0;
383}
384
385struct nfc_phy_ops mei_phy_ops = {
386 .write = nfc_mei_phy_write,
387 .enable = nfc_mei_phy_enable,
388 .disable = nfc_mei_phy_disable,
389};
390EXPORT_SYMBOL_GPL(mei_phy_ops);
391
392struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *cldev)
393{
394 struct nfc_mei_phy *phy;
395
396 phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
397 if (!phy)
398 return NULL;
399
400 phy->cldev = cldev;
401 init_waitqueue_head(&phy->send_wq);
402 mei_cldev_set_drvdata(cldev, phy);
403
404 return phy;
405}
406EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);
407
408void nfc_mei_phy_free(struct nfc_mei_phy *phy)
409{
410 mei_cldev_disable(phy->cldev);
411 kfree(phy);
412}
413EXPORT_SYMBOL_GPL(nfc_mei_phy_free);
414
415MODULE_LICENSE("GPL");
416MODULE_DESCRIPTION("mei bus NFC device interface");
417