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_cmd {
  28         u8 command;
  29         u8 status;
  30         u16 req_id;
  31         u32 reserved;
  32         u16 data_size;
  33         u8 sub_command;
  34         u8 data[];
  35 } __packed;
  36
  37 struct mei_nfc_reply {
  38         u8 command;
  39         u8 status;
  40         u16 req_id;
  41         u32 reserved;
  42         u16 data_size;
  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 struct mei_nfc_hci_hdr {
  73         u8 cmd;
  74         u8 status;
  75         u16 req_id;
  76         u32 reserved;
  77         u16 data_size;
  78 } __packed;
  79
  80 #define MEI_NFC_CMD_MAINTENANCE 0x00
  81 #define MEI_NFC_CMD_HCI_SEND 0x01
  82 #define MEI_NFC_CMD_HCI_RECV 0x02
  83
  84 #define MEI_NFC_SUBCMD_CONNECT    0x00
  85 #define MEI_NFC_SUBCMD_IF_VERSION 0x01
  86
  87 #define MEI_NFC_HEADER_SIZE 10
  88
  89
  90 #define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD)
  91
  92 #define MEI_DUMP_SKB_IN(info, skb)                              \
  93 do {                                                            \
  94         pr_debug("%s:\n", info);                                \
  95         print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET,   \
  96                         16, 1, (skb)->data, (skb)->len, false); \
  97 } while (0)
  98
  99 #define MEI_DUMP_SKB_OUT(info, skb)                             \
 100 do {                                                            \
 101         pr_debug("%s:\n", info);                                \
 102         print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET,   \
 103                         16, 1, (skb)->data, (skb)->len, false); \
 104 } while (0)
 105
 106
 107 static int mei_nfc_if_version(struct nfc_mei_phy *phy)
 108 {
 109
 110         struct mei_nfc_cmd cmd;
 111         struct mei_nfc_reply *reply = NULL;
 112         struct mei_nfc_if_version *version;
 113         size_t if_version_length;
 114         int bytes_recv, r;
 115
 116         pr_info("%s\n", __func__);
 117
 118         memset(&cmd, 0, sizeof(struct mei_nfc_cmd));
 119         cmd.command = MEI_NFC_CMD_MAINTENANCE;
 120         cmd.data_size = 1;
 121         cmd.sub_command = MEI_NFC_SUBCMD_IF_VERSION;
 122
 123         r = mei_cl_send(phy->device, (u8 *)&cmd, sizeof(struct mei_nfc_cmd));
 124         if (r < 0) {
 125                 pr_err("Could not send IF version cmd\n");
 126                 return r;
 127         }
 128
 129         /* to be sure on the stack we alloc memory */
 130         if_version_length = sizeof(struct mei_nfc_reply) +
 131                 sizeof(struct mei_nfc_if_version);
 132
 133         reply = kzalloc(if_version_length, GFP_KERNEL);
 134         if (!reply)
 135                 return -ENOMEM;
 136
 137         bytes_recv = mei_cl_recv(phy->device, (u8 *)reply, if_version_length);
 138         if (bytes_recv < 0 || bytes_recv < sizeof(struct mei_nfc_reply)) {
 139                 pr_err("Could not read IF version\n");
 140                 r = -EIO;
 141                 goto err;
 142         }
 143
 144         version = (struct mei_nfc_if_version *)reply->data;
 145
 146         phy->fw_ivn = version->fw_ivn;
 147         phy->vendor_id = version->vendor_id;
 148         phy->radio_type = version->radio_type;
 149
 150 err:
 151         kfree(reply);
 152         return r;
 153 }
 154
 155 static int mei_nfc_connect(struct nfc_mei_phy *phy)
 156 {
 157         struct mei_nfc_cmd *cmd, *reply;
 158         struct mei_nfc_connect *connect;
 159         struct mei_nfc_connect_resp *connect_resp;
 160         size_t connect_length, connect_resp_length;
 161         int bytes_recv, r;
 162
 163         pr_info("%s\n", __func__);
 164
 165         connect_length = sizeof(struct mei_nfc_cmd) +
 166                         sizeof(struct mei_nfc_connect);
 167
 168         connect_resp_length = sizeof(struct mei_nfc_cmd) +
 169                         sizeof(struct mei_nfc_connect_resp);
 170
 171         cmd = kzalloc(connect_length, GFP_KERNEL);
 172         if (!cmd)
 173                 return -ENOMEM;
 174         connect = (struct mei_nfc_connect *)cmd->data;
 175
 176         reply = kzalloc(connect_resp_length, GFP_KERNEL);
 177         if (!reply) {
 178                 kfree(cmd);
 179                 return -ENOMEM;
 180         }
 181
 182         connect_resp = (struct mei_nfc_connect_resp *)reply->data;
 183
 184         cmd->command = MEI_NFC_CMD_MAINTENANCE;
 185         cmd->data_size = 3;
 186         cmd->sub_command = MEI_NFC_SUBCMD_CONNECT;
 187         connect->fw_ivn = phy->fw_ivn;
 188         connect->vendor_id = phy->vendor_id;
 189
 190         r = mei_cl_send(phy->device, (u8 *)cmd, connect_length);
 191         if (r < 0) {
 192                 pr_err("Could not send connect cmd %d\n", r);
 193                 goto err;
 194         }
 195
 196         bytes_recv = mei_cl_recv(phy->device, (u8 *)reply, 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         pr_info("IVN 0x%x Vendor ID 0x%x\n",
 204                  connect_resp->fw_ivn, connect_resp->vendor_id);
 205
 206         pr_info("ME FW %d.%d.%d.%d\n",
 207                 connect_resp->me_major, connect_resp->me_minor,
 208                 connect_resp->me_hotfix, connect_resp->me_build);
 209
 210         r = 0;
 211
 212 err:
 213         kfree(reply);
 214         kfree(cmd);
 215
 216         return r;
 217 }
 218
 219 static int mei_nfc_send(struct nfc_mei_phy *phy, u8 *buf, size_t length)
 220 {
 221         struct mei_nfc_hci_hdr *hdr;
 222         u8 *mei_buf;
 223         int err;
 224
 225         err = -ENOMEM;
 226         mei_buf = kzalloc(length + MEI_NFC_HEADER_SIZE, GFP_KERNEL);
 227         if (!mei_buf)
 228                 goto out;
 229
 230         hdr = (struct mei_nfc_hci_hdr *) mei_buf;
 231         hdr->cmd = MEI_NFC_CMD_HCI_SEND;
 232         hdr->status = 0;
 233         hdr->req_id = phy->req_id;
 234         hdr->reserved = 0;
 235         hdr->data_size = length;
 236
 237         memcpy(mei_buf + MEI_NFC_HEADER_SIZE, buf, length);
 238         err = mei_cl_send(phy->device, mei_buf, length + MEI_NFC_HEADER_SIZE);
 239         if (err < 0)
 240                 goto out;
 241
 242         if (!wait_event_interruptible_timeout(phy->send_wq,
 243                                 phy->recv_req_id == phy->req_id, HZ)) {
 244                 pr_err("NFC MEI command timeout\n");
 245                 err = -ETIME;
 246         } else {
 247                 phy->req_id++;
 248         }
 249 out:
 250         kfree(mei_buf);
 251         return err;
 252 }
 253
 254 /*
 255  * Writing a frame must not return the number of written bytes.
 256  * It must return either zero for success, or <0 for error.
 257  * In addition, it must not alter the skb
 258  */
 259 static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb)
 260 {
 261         struct nfc_mei_phy *phy = phy_id;
 262         int r;
 263
 264         MEI_DUMP_SKB_OUT("mei frame sent", skb);
 265
 266         r = mei_nfc_send(phy, skb->data, skb->len);
 267         if (r > 0)
 268                 r = 0;
 269
 270         return r;
 271 }
 272
 273 static int mei_nfc_recv(struct nfc_mei_phy *phy, u8 *buf, size_t length)
 274 {
 275         struct mei_nfc_hci_hdr *hci_hdr;
 276         int received_length;
 277
 278         received_length = mei_cl_recv(phy->device, buf, length);
 279         if (received_length < 0)
 280                 return received_length;
 281
 282         hci_hdr = (struct mei_nfc_hci_hdr *) buf;
 283
 284         if (hci_hdr->cmd == MEI_NFC_CMD_HCI_SEND) {
 285                 phy->recv_req_id = hci_hdr->req_id;
 286                 wake_up(&phy->send_wq);
 287
 288                 return 0;
 289         }
 290
 291         return received_length;
 292 }
 293
 294
 295 static void nfc_mei_event_cb(struct mei_cl_device *device, u32 events,
 296                              void *context)
 297 {
 298         struct nfc_mei_phy *phy = context;
 299
 300         if (phy->hard_fault != 0)
 301                 return;
 302
 303         if (events & BIT(MEI_CL_EVENT_RX)) {
 304                 struct sk_buff *skb;
 305                 int reply_size;
 306
 307                 skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
 308                 if (!skb)
 309                         return;
 310
 311                 reply_size = mei_nfc_recv(phy, skb->data, MEI_NFC_MAX_READ);
 312                 if (reply_size < MEI_NFC_HEADER_SIZE) {
 313                         kfree_skb(skb);
 314                         return;
 315                 }
 316
 317                 skb_put(skb, reply_size);
 318                 skb_pull(skb, MEI_NFC_HEADER_SIZE);
 319
 320                 MEI_DUMP_SKB_IN("mei frame read", skb);
 321
 322                 nfc_hci_recv_frame(phy->hdev, skb);
 323         }
 324 }
 325
 326 static int nfc_mei_phy_enable(void *phy_id)
 327 {
 328         int r;
 329         struct nfc_mei_phy *phy = phy_id;
 330
 331         pr_info("%s\n", __func__);
 332
 333         if (phy->powered == 1)
 334                 return 0;
 335
 336         r = mei_cl_enable_device(phy->device);
 337         if (r < 0) {
 338                 pr_err("Could not enable device %d\n", r);
 339                 return r;
 340         }
 341
 342         r = mei_nfc_if_version(phy);
 343         if (r < 0) {
 344                 pr_err("Could not enable device %d\n", r);
 345                 goto err;
 346         }
 347
 348         r = mei_nfc_connect(phy);
 349         if (r < 0) {
 350                 pr_err("Could not connect to device %d\n", r);
 351                 goto err;
 352         }
 353
 354         r = mei_cl_register_event_cb(phy->device, nfc_mei_event_cb, phy);
 355         if (r) {
 356                 pr_err("Event cb registration failed %d\n", r);
 357                 goto err;
 358         }
 359
 360         phy->powered = 1;
 361
 362         return 0;
 363
 364 err:
 365         phy->powered = 0;
 366         mei_cl_disable_device(phy->device);
 367         return r;
 368 }
 369
 370 static void nfc_mei_phy_disable(void *phy_id)
 371 {
 372         struct nfc_mei_phy *phy = phy_id;
 373
 374         pr_info("%s\n", __func__);
 375
 376         mei_cl_disable_device(phy->device);
 377
 378         phy->powered = 0;
 379 }
 380
 381 struct nfc_phy_ops mei_phy_ops = {
 382         .write = nfc_mei_phy_write,
 383         .enable = nfc_mei_phy_enable,
 384         .disable = nfc_mei_phy_disable,
 385 };
 386 EXPORT_SYMBOL_GPL(mei_phy_ops);
 387
 388 struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *device)
 389 {
 390         struct nfc_mei_phy *phy;
 391
 392         phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
 393         if (!phy)
 394                 return NULL;
 395
 396         phy->device = device;
 397         init_waitqueue_head(&phy->send_wq);
 398         mei_cl_set_drvdata(device, phy);
 399
 400         return phy;
 401 }
 402 EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);
 403
 404 void nfc_mei_phy_free(struct nfc_mei_phy *phy)
 405 {
 406         mei_cl_disable_device(phy->device);
 407         kfree(phy);
 408 }
 409 EXPORT_SYMBOL_GPL(nfc_mei_phy_free);
 410
 411 MODULE_LICENSE("GPL");
 412 MODULE_DESCRIPTION("mei bus NFC device interface");