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        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
 134err:
 135        kfree(reply);
 136        return r;
 137}
 138
 139static 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
 198err:
 199        kfree(reply);
 200        kfree(cmd);
 201
 202        return r;
 203}
 204
 205static int mei_nfc_send(struct nfc_mei_phy *phy, 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        }
 237out:
 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 */
 247static 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
 261static 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
 284static 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
 314static 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
 350err:
 351        phy->powered = 0;
 352        mei_cldev_disable(phy->cldev);
 353        return r;
 354}
 355
 356static 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
 365struct 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};
 370EXPORT_SYMBOL_GPL(mei_phy_ops);
 371
 372struct 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}
 386EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);
 387
 388void nfc_mei_phy_free(struct nfc_mei_phy *phy)
 389{
 390        mei_cldev_disable(phy->cldev);
 391        kfree(phy);
 392}
 393EXPORT_SYMBOL_GPL(nfc_mei_phy_free);
 394
 395MODULE_LICENSE("GPL");
 396MODULE_DESCRIPTION("mei bus NFC device interface");
 397