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