xref: /openbmc/linux/drivers/nfc/mei_phy.c (revision 894a6e15)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2013, Intel Corporation.
4  *
5  * MEI Library for mei bus nfc device access
6  */
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/nfc.h>
12 
13 #include "mei_phy.h"
14 
15 struct mei_nfc_hdr {
16 	u8 cmd;
17 	u8 status;
18 	u16 req_id;
19 	u32 reserved;
20 	u16 data_size;
21 } __packed;
22 
23 struct mei_nfc_cmd {
24 	struct mei_nfc_hdr hdr;
25 	u8 sub_command;
26 	u8 data[];
27 } __packed;
28 
29 struct mei_nfc_reply {
30 	struct mei_nfc_hdr hdr;
31 	u8 sub_command;
32 	u8 reply_status;
33 	u8 data[];
34 } __packed;
35 
36 struct mei_nfc_if_version {
37 	u8 radio_version_sw[3];
38 	u8 reserved[3];
39 	u8 radio_version_hw[3];
40 	u8 i2c_addr;
41 	u8 fw_ivn;
42 	u8 vendor_id;
43 	u8 radio_type;
44 } __packed;
45 
46 struct mei_nfc_connect {
47 	u8 fw_ivn;
48 	u8 vendor_id;
49 } __packed;
50 
51 struct mei_nfc_connect_resp {
52 	u8 fw_ivn;
53 	u8 vendor_id;
54 	u16 me_major;
55 	u16 me_minor;
56 	u16 me_hotfix;
57 	u16 me_build;
58 } __packed;
59 
60 
61 #define MEI_NFC_CMD_MAINTENANCE 0x00
62 #define MEI_NFC_CMD_HCI_SEND 0x01
63 #define MEI_NFC_CMD_HCI_RECV 0x02
64 
65 #define MEI_NFC_SUBCMD_CONNECT    0x00
66 #define MEI_NFC_SUBCMD_IF_VERSION 0x01
67 
68 #define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD)
69 
70 #define MEI_DUMP_SKB_IN(info, skb)				\
71 do {								\
72 	pr_debug("%s:\n", info);				\
73 	print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET,	\
74 			16, 1, (skb)->data, (skb)->len, false);	\
75 } while (0)
76 
77 #define MEI_DUMP_SKB_OUT(info, skb)				\
78 do {								\
79 	pr_debug("%s:\n", info);				\
80 	print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET,	\
81 			16, 1, (skb)->data, (skb)->len, false);	\
82 } while (0)
83 
84 #define MEI_DUMP_NFC_HDR(info, _hdr)                                \
85 do {                                                                \
86 	pr_debug("%s:\n", info);                                    \
87 	pr_debug("cmd=%02d status=%d req_id=%d rsvd=%d size=%d\n",  \
88 		 (_hdr)->cmd, (_hdr)->status, (_hdr)->req_id,       \
89 		 (_hdr)->reserved, (_hdr)->data_size);              \
90 } while (0)
91 
mei_nfc_if_version(struct nfc_mei_phy * phy)92 static int mei_nfc_if_version(struct nfc_mei_phy *phy)
93 {
94 
95 	struct mei_nfc_cmd cmd;
96 	struct mei_nfc_reply *reply = NULL;
97 	struct mei_nfc_if_version *version;
98 	size_t if_version_length;
99 	int bytes_recv, r;
100 
101 	memset(&cmd, 0, sizeof(struct mei_nfc_cmd));
102 	cmd.hdr.cmd = MEI_NFC_CMD_MAINTENANCE;
103 	cmd.hdr.data_size = 1;
104 	cmd.sub_command = MEI_NFC_SUBCMD_IF_VERSION;
105 
106 	MEI_DUMP_NFC_HDR("version", &cmd.hdr);
107 	r = mei_cldev_send(phy->cldev, (u8 *)&cmd, sizeof(struct mei_nfc_cmd));
108 	if (r < 0) {
109 		pr_err("Could not send IF version cmd\n");
110 		return r;
111 	}
112 
113 	/* to be sure on the stack we alloc memory */
114 	if_version_length = sizeof(struct mei_nfc_reply) +
115 		sizeof(struct mei_nfc_if_version);
116 
117 	reply = kzalloc(if_version_length, GFP_KERNEL);
118 	if (!reply)
119 		return -ENOMEM;
120 
121 	bytes_recv = mei_cldev_recv(phy->cldev, (u8 *)reply, if_version_length);
122 	if (bytes_recv < 0 || bytes_recv < if_version_length) {
123 		pr_err("Could not read IF version\n");
124 		r = -EIO;
125 		goto err;
126 	}
127 
128 	version = (struct mei_nfc_if_version *)reply->data;
129 
130 	phy->fw_ivn = version->fw_ivn;
131 	phy->vendor_id = version->vendor_id;
132 	phy->radio_type = version->radio_type;
133 
134 err:
135 	kfree(reply);
136 	return r;
137 }
138 
mei_nfc_connect(struct nfc_mei_phy * phy)139 static int mei_nfc_connect(struct nfc_mei_phy *phy)
140 {
141 	struct mei_nfc_cmd *cmd, *reply;
142 	struct mei_nfc_connect *connect;
143 	struct mei_nfc_connect_resp *connect_resp;
144 	size_t connect_length, connect_resp_length;
145 	int bytes_recv, r;
146 
147 	connect_length = sizeof(struct mei_nfc_cmd) +
148 			sizeof(struct mei_nfc_connect);
149 
150 	connect_resp_length = sizeof(struct mei_nfc_cmd) +
151 			sizeof(struct mei_nfc_connect_resp);
152 
153 	cmd = kzalloc(connect_length, GFP_KERNEL);
154 	if (!cmd)
155 		return -ENOMEM;
156 	connect = (struct mei_nfc_connect *)cmd->data;
157 
158 	reply = kzalloc(connect_resp_length, GFP_KERNEL);
159 	if (!reply) {
160 		kfree(cmd);
161 		return -ENOMEM;
162 	}
163 
164 	connect_resp = (struct mei_nfc_connect_resp *)reply->data;
165 
166 	cmd->hdr.cmd = MEI_NFC_CMD_MAINTENANCE;
167 	cmd->hdr.data_size = 3;
168 	cmd->sub_command = MEI_NFC_SUBCMD_CONNECT;
169 	connect->fw_ivn = phy->fw_ivn;
170 	connect->vendor_id = phy->vendor_id;
171 
172 	MEI_DUMP_NFC_HDR("connect request", &cmd->hdr);
173 	r = mei_cldev_send(phy->cldev, (u8 *)cmd, connect_length);
174 	if (r < 0) {
175 		pr_err("Could not send connect cmd %d\n", r);
176 		goto err;
177 	}
178 
179 	bytes_recv = mei_cldev_recv(phy->cldev, (u8 *)reply,
180 				    connect_resp_length);
181 	if (bytes_recv < 0) {
182 		r = bytes_recv;
183 		pr_err("Could not read connect response %d\n", r);
184 		goto err;
185 	}
186 
187 	MEI_DUMP_NFC_HDR("connect reply", &reply->hdr);
188 
189 	pr_info("IVN 0x%x Vendor ID 0x%x\n",
190 		 connect_resp->fw_ivn, connect_resp->vendor_id);
191 
192 	pr_info("ME FW %d.%d.%d.%d\n",
193 		connect_resp->me_major, connect_resp->me_minor,
194 		connect_resp->me_hotfix, connect_resp->me_build);
195 
196 	r = 0;
197 
198 err:
199 	kfree(reply);
200 	kfree(cmd);
201 
202 	return r;
203 }
204 
mei_nfc_send(struct nfc_mei_phy * phy,const u8 * buf,size_t length)205 static int mei_nfc_send(struct nfc_mei_phy *phy, const u8 *buf, size_t length)
206 {
207 	struct mei_nfc_hdr *hdr;
208 	u8 *mei_buf;
209 	int err;
210 
211 	err = -ENOMEM;
212 	mei_buf = kzalloc(length + MEI_NFC_HEADER_SIZE, GFP_KERNEL);
213 	if (!mei_buf)
214 		goto out;
215 
216 	hdr = (struct mei_nfc_hdr *)mei_buf;
217 	hdr->cmd = MEI_NFC_CMD_HCI_SEND;
218 	hdr->status = 0;
219 	hdr->req_id = phy->req_id;
220 	hdr->reserved = 0;
221 	hdr->data_size = length;
222 
223 	MEI_DUMP_NFC_HDR("send", hdr);
224 
225 	memcpy(mei_buf + MEI_NFC_HEADER_SIZE, buf, length);
226 	err = mei_cldev_send(phy->cldev, mei_buf, length + MEI_NFC_HEADER_SIZE);
227 	if (err < 0)
228 		goto out;
229 
230 	if (!wait_event_interruptible_timeout(phy->send_wq,
231 				phy->recv_req_id == phy->req_id, HZ)) {
232 		pr_err("NFC MEI command timeout\n");
233 		err = -ETIME;
234 	} else {
235 		phy->req_id++;
236 	}
237 out:
238 	kfree(mei_buf);
239 	return err;
240 }
241 
242 /*
243  * Writing a frame must not return the number of written bytes.
244  * It must return either zero for success, or <0 for error.
245  * In addition, it must not alter the skb
246  */
nfc_mei_phy_write(void * phy_id,struct sk_buff * skb)247 static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb)
248 {
249 	struct nfc_mei_phy *phy = phy_id;
250 	int r;
251 
252 	MEI_DUMP_SKB_OUT("mei frame sent", skb);
253 
254 	r = mei_nfc_send(phy, skb->data, skb->len);
255 	if (r > 0)
256 		r = 0;
257 
258 	return r;
259 }
260 
mei_nfc_recv(struct nfc_mei_phy * phy,u8 * buf,size_t length)261 static int mei_nfc_recv(struct nfc_mei_phy *phy, u8 *buf, size_t length)
262 {
263 	struct mei_nfc_hdr *hdr;
264 	int received_length;
265 
266 	received_length = mei_cldev_recv(phy->cldev, buf, length);
267 	if (received_length < 0)
268 		return received_length;
269 
270 	hdr = (struct mei_nfc_hdr *) buf;
271 
272 	MEI_DUMP_NFC_HDR("receive", hdr);
273 	if (hdr->cmd == MEI_NFC_CMD_HCI_SEND) {
274 		phy->recv_req_id = hdr->req_id;
275 		wake_up(&phy->send_wq);
276 
277 		return 0;
278 	}
279 
280 	return received_length;
281 }
282 
283 
nfc_mei_rx_cb(struct mei_cl_device * cldev)284 static void nfc_mei_rx_cb(struct mei_cl_device *cldev)
285 {
286 	struct nfc_mei_phy *phy = mei_cldev_get_drvdata(cldev);
287 	struct sk_buff *skb;
288 	int reply_size;
289 
290 	if (!phy)
291 		return;
292 
293 	if (phy->hard_fault != 0)
294 		return;
295 
296 	skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
297 	if (!skb)
298 		return;
299 
300 	reply_size = mei_nfc_recv(phy, skb->data, MEI_NFC_MAX_READ);
301 	if (reply_size < MEI_NFC_HEADER_SIZE) {
302 		kfree_skb(skb);
303 		return;
304 	}
305 
306 	skb_put(skb, reply_size);
307 	skb_pull(skb, MEI_NFC_HEADER_SIZE);
308 
309 	MEI_DUMP_SKB_IN("mei frame read", skb);
310 
311 	nfc_hci_recv_frame(phy->hdev, skb);
312 }
313 
nfc_mei_phy_enable(void * phy_id)314 static int nfc_mei_phy_enable(void *phy_id)
315 {
316 	int r;
317 	struct nfc_mei_phy *phy = phy_id;
318 
319 	if (phy->powered == 1)
320 		return 0;
321 
322 	r = mei_cldev_enable(phy->cldev);
323 	if (r < 0) {
324 		pr_err("Could not enable device %d\n", r);
325 		return r;
326 	}
327 
328 	r = mei_nfc_if_version(phy);
329 	if (r < 0) {
330 		pr_err("Could not enable device %d\n", r);
331 		goto err;
332 	}
333 
334 	r = mei_nfc_connect(phy);
335 	if (r < 0) {
336 		pr_err("Could not connect to device %d\n", r);
337 		goto err;
338 	}
339 
340 	r = mei_cldev_register_rx_cb(phy->cldev, nfc_mei_rx_cb);
341 	if (r) {
342 		pr_err("Event cb registration failed %d\n", r);
343 		goto err;
344 	}
345 
346 	phy->powered = 1;
347 
348 	return 0;
349 
350 err:
351 	phy->powered = 0;
352 	mei_cldev_disable(phy->cldev);
353 	return r;
354 }
355 
nfc_mei_phy_disable(void * phy_id)356 static void nfc_mei_phy_disable(void *phy_id)
357 {
358 	struct nfc_mei_phy *phy = phy_id;
359 
360 	mei_cldev_disable(phy->cldev);
361 
362 	phy->powered = 0;
363 }
364 
365 const struct nfc_phy_ops mei_phy_ops = {
366 	.write = nfc_mei_phy_write,
367 	.enable = nfc_mei_phy_enable,
368 	.disable = nfc_mei_phy_disable,
369 };
370 EXPORT_SYMBOL_GPL(mei_phy_ops);
371 
nfc_mei_phy_alloc(struct mei_cl_device * cldev)372 struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *cldev)
373 {
374 	struct nfc_mei_phy *phy;
375 
376 	phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
377 	if (!phy)
378 		return NULL;
379 
380 	phy->cldev = cldev;
381 	init_waitqueue_head(&phy->send_wq);
382 	mei_cldev_set_drvdata(cldev, phy);
383 
384 	return phy;
385 }
386 EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);
387 
nfc_mei_phy_free(struct nfc_mei_phy * phy)388 void nfc_mei_phy_free(struct nfc_mei_phy *phy)
389 {
390 	mei_cldev_disable(phy->cldev);
391 	kfree(phy);
392 }
393 EXPORT_SYMBOL_GPL(nfc_mei_phy_free);
394 
395 MODULE_LICENSE("GPL");
396 MODULE_DESCRIPTION("mei bus NFC device interface");
397