drivers/nfc/mei_phy.c

   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
  27 struct mei_nfc_hdr {
  28         u8 cmd;
  29         u8 status;
  30         u16 req_id;
  31         u32 reserved;
  32         u16 data_size;
  33 } __packed;
  34
  35 struct mei_nfc_cmd {
  36         struct mei_nfc_hdr hdr;
  37         u8 sub_command;
  38         u8 data[];
  39 } __packed;
  40
  41 struct mei_nfc_reply {
  42         struct mei_nfc_hdr hdr;
  43         u8 sub_command;
  44         u8 reply_status;
  45         u8 data[];
  46 } __packed;
  47
  48 struct 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
  58 struct mei_nfc_connect {
  59         u8 fw_ivn;
  60         u8 vendor_id;
  61 } __packed;
  62
  63 struct 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)                              \
  83 do {                                                            \
  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)                             \
  90 do {                                                            \
  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)                                \
  97 do {                                                                \
  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
 104 static 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_cl_send(phy->device, (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_cl_recv(phy->device, (u8 *)reply, if_version_length);
 136         if (bytes_recv < 0 || bytes_recv < sizeof(struct mei_nfc_reply)) {
 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
 148 err:
 149         kfree(reply);
 150         return r;
 151 }
 152
 153 static 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_cl_send(phy->device, (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_cl_recv(phy->device, (u8 *)reply, connect_resp_length);
 196         if (bytes_recv < 0) {
 197                 r = bytes_recv;
 198                 pr_err("Could not read connect response %d\n", r);
 199                 goto err;
 200         }
 201
 202         MEI_DUMP_NFC_HDR("connect reply", &reply->hdr);
 203
 204         pr_info("IVN 0x%x Vendor ID 0x%x\n",
 205                  connect_resp->fw_ivn, connect_resp->vendor_id);
 206
 207         pr_info("ME FW %d.%d.%d.%d\n",
 208                 connect_resp->me_major, connect_resp->me_minor,
 209                 connect_resp->me_hotfix, connect_resp->me_build);
 210
 211         r = 0;
 212
 213 err:
 214         kfree(reply);
 215         kfree(cmd);
 216
 217         return r;
 218 }
 219
 220 static int mei_nfc_send(struct nfc_mei_phy *phy, u8 *buf, size_t length)
 221 {
 222         struct mei_nfc_hdr *hdr;
 223         u8 *mei_buf;
 224         int err;
 225
 226         err = -ENOMEM;
 227         mei_buf = kzalloc(length + MEI_NFC_HEADER_SIZE, GFP_KERNEL);
 228         if (!mei_buf)
 229                 goto out;
 230
 231         hdr = (struct mei_nfc_hdr *)mei_buf;
 232         hdr->cmd = MEI_NFC_CMD_HCI_SEND;
 233         hdr->status = 0;
 234         hdr->req_id = phy->req_id;
 235         hdr->reserved = 0;
 236         hdr->data_size = length;
 237
 238         MEI_DUMP_NFC_HDR("send", hdr);
 239
 240         memcpy(mei_buf + MEI_NFC_HEADER_SIZE, buf, length);
 241         err = mei_cl_send(phy->device, mei_buf, length + MEI_NFC_HEADER_SIZE);
 242         if (err < 0)
 243                 goto out;
 244
 245         if (!wait_event_interruptible_timeout(phy->send_wq,
 246                                 phy->recv_req_id == phy->req_id, HZ)) {
 247                 pr_err("NFC MEI command timeout\n");
 248                 err = -ETIME;
 249         } else {
 250                 phy->req_id++;
 251         }
 252 out:
 253         kfree(mei_buf);
 254         return err;
 255 }
 256
 257 /*
 258  * Writing a frame must not return the number of written bytes.
 259  * It must return either zero for success, or <0 for error.
 260  * In addition, it must not alter the skb
 261  */
 262 static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb)
 263 {
 264         struct nfc_mei_phy *phy = phy_id;
 265         int r;
 266
 267         MEI_DUMP_SKB_OUT("mei frame sent", skb);
 268
 269         r = mei_nfc_send(phy, skb->data, skb->len);
 270         if (r > 0)
 271                 r = 0;
 272
 273         return r;
 274 }
 275
 276 static int mei_nfc_recv(struct nfc_mei_phy *phy, u8 *buf, size_t length)
 277 {
 278         struct mei_nfc_hdr *hdr;
 279         int received_length;
 280
 281         received_length = mei_cl_recv(phy->device, buf, length);
 282         if (received_length < 0)
 283                 return received_length;
 284
 285         hdr = (struct mei_nfc_hdr *) buf;
 286
 287         MEI_DUMP_NFC_HDR("receive", hdr);
 288         if (hdr->cmd == MEI_NFC_CMD_HCI_SEND) {
 289                 phy->recv_req_id = hdr->req_id;
 290                 wake_up(&phy->send_wq);
 291
 292                 return 0;
 293         }
 294
 295         return received_length;
 296 }
 297
 298
 299 static void nfc_mei_event_cb(struct mei_cl_device *device, u32 events,
 300                              void *context)
 301 {
 302         struct nfc_mei_phy *phy = context;
 303
 304         if (phy->hard_fault != 0)
 305                 return;
 306
 307         if (events & BIT(MEI_CL_EVENT_RX)) {
 308                 struct sk_buff *skb;
 309                 int reply_size;
 310
 311                 skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
 312                 if (!skb)
 313                         return;
 314
 315                 reply_size = mei_nfc_recv(phy, skb->data, MEI_NFC_MAX_READ);
 316                 if (reply_size < MEI_NFC_HEADER_SIZE) {
 317                         kfree_skb(skb);
 318                         return;
 319                 }
 320
 321                 skb_put(skb, reply_size);
 322                 skb_pull(skb, MEI_NFC_HEADER_SIZE);
 323
 324                 MEI_DUMP_SKB_IN("mei frame read", skb);
 325
 326                 nfc_hci_recv_frame(phy->hdev, skb);
 327         }
 328 }
 329
 330 static 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_cl_enable_device(phy->device);
 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_cl_register_event_cb(phy->device, BIT(MEI_CL_EVENT_RX),
 359                                      nfc_mei_event_cb, phy);
 360         if (r) {
 361                 pr_err("Event cb registration failed %d\n", r);
 362                 goto err;
 363         }
 364
 365         phy->powered = 1;
 366
 367         return 0;
 368
 369 err:
 370         phy->powered = 0;
 371         mei_cl_disable_device(phy->device);
 372         return r;
 373 }
 374
 375 static void nfc_mei_phy_disable(void *phy_id)
 376 {
 377         struct nfc_mei_phy *phy = phy_id;
 378
 379         pr_info("%s\n", __func__);
 380
 381         mei_cl_disable_device(phy->device);
 382
 383         phy->powered = 0;
 384 }
 385
 386 struct nfc_phy_ops mei_phy_ops = {
 387         .write = nfc_mei_phy_write,
 388         .enable = nfc_mei_phy_enable,
 389         .disable = nfc_mei_phy_disable,
 390 };
 391 EXPORT_SYMBOL_GPL(mei_phy_ops);
 392
 393 struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *device)
 394 {
 395         struct nfc_mei_phy *phy;
 396
 397         phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
 398         if (!phy)
 399                 return NULL;
 400
 401         phy->device = device;
 402         init_waitqueue_head(&phy->send_wq);
 403         mei_cl_set_drvdata(device, phy);
 404
 405         return phy;
 406 }
 407 EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);
 408
 409 void nfc_mei_phy_free(struct nfc_mei_phy *phy)
 410 {
 411         mei_cl_disable_device(phy->device);
 412         kfree(phy);
 413 }
 414 EXPORT_SYMBOL_GPL(nfc_mei_phy_free);
 415
 416 MODULE_LICENSE("GPL");
 417 MODULE_DESCRIPTION("mei bus NFC device interface");