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_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 < 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_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
 214 err:
 215         kfree(reply);
 216         kfree(cmd);
 217
 218         return r;
 219 }
 220
 221 static 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         }
 253 out:
 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  */
 263 static 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
 277 static 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
 300 static void nfc_mei_event_cb(struct mei_cl_device *cldev, u32 events,
 301                              void *context)
 302 {
 303         struct nfc_mei_phy *phy = context;
 304
 305         if (phy->hard_fault != 0)
 306                 return;
 307
 308         if (events & BIT(MEI_CL_EVENT_RX)) {
 309                 struct sk_buff *skb;
 310                 int reply_size;
 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 }
 330
 331 static int nfc_mei_phy_enable(void *phy_id)
 332 {
 333         int r;
 334         struct nfc_mei_phy *phy = phy_id;
 335
 336         pr_info("%s\n", __func__);
 337
 338         if (phy->powered == 1)
 339                 return 0;
 340
 341         r = mei_cldev_enable(phy->cldev);
 342         if (r < 0) {
 343                 pr_err("Could not enable device %d\n", r);
 344                 return r;
 345         }
 346
 347         r = mei_nfc_if_version(phy);
 348         if (r < 0) {
 349                 pr_err("Could not enable device %d\n", r);
 350                 goto err;
 351         }
 352
 353         r = mei_nfc_connect(phy);
 354         if (r < 0) {
 355                 pr_err("Could not connect to device %d\n", r);
 356                 goto err;
 357         }
 358
 359         r = mei_cldev_register_event_cb(phy->cldev, BIT(MEI_CL_EVENT_RX),
 360                                      nfc_mei_event_cb, phy);
 361         if (r) {
 362                 pr_err("Event cb registration failed %d\n", r);
 363                 goto err;
 364         }
 365
 366         phy->powered = 1;
 367
 368         return 0;
 369
 370 err:
 371         phy->powered = 0;
 372         mei_cldev_disable(phy->cldev);
 373         return r;
 374 }
 375
 376 static void nfc_mei_phy_disable(void *phy_id)
 377 {
 378         struct nfc_mei_phy *phy = phy_id;
 379
 380         pr_info("%s\n", __func__);
 381
 382         mei_cldev_disable(phy->cldev);
 383
 384         phy->powered = 0;
 385 }
 386
 387 struct nfc_phy_ops mei_phy_ops = {
 388         .write = nfc_mei_phy_write,
 389         .enable = nfc_mei_phy_enable,
 390         .disable = nfc_mei_phy_disable,
 391 };
 392 EXPORT_SYMBOL_GPL(mei_phy_ops);
 393
 394 struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *cldev)
 395 {
 396         struct nfc_mei_phy *phy;
 397
 398         phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
 399         if (!phy)
 400                 return NULL;
 401
 402         phy->cldev = cldev;
 403         init_waitqueue_head(&phy->send_wq);
 404         mei_cldev_set_drvdata(cldev, phy);
 405
 406         return phy;
 407 }
 408 EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);
 409
 410 void nfc_mei_phy_free(struct nfc_mei_phy *phy)
 411 {
 412         mei_cldev_disable(phy->cldev);
 413         kfree(phy);
 414 }
 415 EXPORT_SYMBOL_GPL(nfc_mei_phy_free);
 416
 417 MODULE_LICENSE("GPL");
 418 MODULE_DESCRIPTION("mei bus NFC device interface");