drivers/misc/mei/bus-fixup.c

   1 /*
   2  *
   3  * Intel Management Engine Interface (Intel MEI) Linux driver
   4  * Copyright (c) 2003-2013, Intel Corporation.
   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 it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/sched.h>
  19 #include <linux/module.h>
  20 #include <linux/moduleparam.h>
  21 #include <linux/device.h>
  22 #include <linux/slab.h>
  23 #include <linux/uuid.h>
  24
  25 #include <linux/mei_cl_bus.h>
  26
  27 #include "mei_dev.h"
  28 #include "client.h"
  29
  30 #define MEI_UUID_NFC_INFO UUID_LE(0xd2de1625, 0x382d, 0x417d, \
  31                         0x48, 0xa4, 0xef, 0xab, 0xba, 0x8a, 0x12, 0x06)
  32
  33 static const uuid_le mei_nfc_info_guid = MEI_UUID_NFC_INFO;
  34
  35 #define MEI_UUID_NFC_HCI UUID_LE(0x0bb17a78, 0x2a8e, 0x4c50, \
  36                         0x94, 0xd4, 0x50, 0x26, 0x67, 0x23, 0x77, 0x5c)
  37
  38 #define MEI_UUID_ANY NULL_UUID_LE
  39
  40 /**
  41  * number_of_connections - determine whether an client be on the bus
  42  *    according number of connections
  43  *    We support only clients:
  44  *       1. with single connection
  45  *       2. and fixed clients (max_number_of_connections == 0)
  46  *
  47  * @cldev: me clients device
  48  */
  49 static void number_of_connections(struct mei_cl_device *cldev)
  50 {
  51         dev_dbg(&cldev->dev, "running hook %s on %pUl\n",
  52                         __func__, mei_me_cl_uuid(cldev->me_cl));
  53
  54         if (cldev->me_cl->props.max_number_of_connections > 1)
  55                 cldev->do_match = 0;
  56 }
  57
  58 /**
  59  * blacklist - blacklist a client from the bus
  60  *
  61  * @cldev: me clients device
  62  */
  63 static void blacklist(struct mei_cl_device *cldev)
  64 {
  65         dev_dbg(&cldev->dev, "running hook %s on %pUl\n",
  66                         __func__, mei_me_cl_uuid(cldev->me_cl));
  67         cldev->do_match = 0;
  68 }
  69
  70 struct mei_nfc_cmd {
  71         u8 command;
  72         u8 status;
  73         u16 req_id;
  74         u32 reserved;
  75         u16 data_size;
  76         u8 sub_command;
  77         u8 data[];
  78 } __packed;
  79
  80 struct mei_nfc_reply {
  81         u8 command;
  82         u8 status;
  83         u16 req_id;
  84         u32 reserved;
  85         u16 data_size;
  86         u8 sub_command;
  87         u8 reply_status;
  88         u8 data[];
  89 } __packed;
  90
  91 struct mei_nfc_if_version {
  92         u8 radio_version_sw[3];
  93         u8 reserved[3];
  94         u8 radio_version_hw[3];
  95         u8 i2c_addr;
  96         u8 fw_ivn;
  97         u8 vendor_id;
  98         u8 radio_type;
  99 } __packed;
 100
 101
 102 #define MEI_NFC_CMD_MAINTENANCE 0x00
 103 #define MEI_NFC_SUBCMD_IF_VERSION 0x01
 104
 105 /* Vendors */
 106 #define MEI_NFC_VENDOR_INSIDE 0x00
 107 #define MEI_NFC_VENDOR_NXP    0x01
 108
 109 /* Radio types */
 110 #define MEI_NFC_VENDOR_INSIDE_UREAD 0x00
 111 #define MEI_NFC_VENDOR_NXP_PN544    0x01
 112
 113 /**
 114  * mei_nfc_if_version - get NFC interface version
 115  *
 116  * @cl: host client (nfc info)
 117  * @ver: NFC interface version to be filled in
 118  *
 119  * Return: 0 on success; < 0 otherwise
 120  */
 121 static int mei_nfc_if_version(struct mei_cl *cl,
 122                               struct mei_nfc_if_version *ver)
 123 {
 124         struct mei_device *bus;
 125         struct mei_nfc_cmd cmd = {
 126                 .command = MEI_NFC_CMD_MAINTENANCE,
 127                 .data_size = 1,
 128                 .sub_command = MEI_NFC_SUBCMD_IF_VERSION,
 129         };
 130         struct mei_nfc_reply *reply = NULL;
 131         size_t if_version_length;
 132         int bytes_recv, ret;
 133
 134         bus = cl->dev;
 135
 136         WARN_ON(mutex_is_locked(&bus->device_lock));
 137
 138         ret = __mei_cl_send(cl, (u8 *)&cmd, sizeof(struct mei_nfc_cmd), 1);
 139         if (ret < 0) {
 140                 dev_err(bus->dev, "Could not send IF version cmd\n");
 141                 return ret;
 142         }
 143
 144         /* to be sure on the stack we alloc memory */
 145         if_version_length = sizeof(struct mei_nfc_reply) +
 146                 sizeof(struct mei_nfc_if_version);
 147
 148         reply = kzalloc(if_version_length, GFP_KERNEL);
 149         if (!reply)
 150                 return -ENOMEM;
 151
 152         ret = 0;
 153         bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length);
 154         if (bytes_recv < 0 || bytes_recv < sizeof(struct mei_nfc_reply)) {
 155                 dev_err(bus->dev, "Could not read IF version\n");
 156                 ret = -EIO;
 157                 goto err;
 158         }
 159
 160         memcpy(ver, reply->data, sizeof(struct mei_nfc_if_version));
 161
 162         dev_info(bus->dev, "NFC MEI VERSION: IVN 0x%x Vendor ID 0x%x Type 0x%x\n",
 163                 ver->fw_ivn, ver->vendor_id, ver->radio_type);
 164
 165 err:
 166         kfree(reply);
 167         return ret;
 168 }
 169
 170 /**
 171  * mei_nfc_radio_name - derive nfc radio name from the interface version
 172  *
 173  * @ver: NFC radio version
 174  *
 175  * Return: radio name string
 176  */
 177 static const char *mei_nfc_radio_name(struct mei_nfc_if_version *ver)
 178 {
 179
 180         if (ver->vendor_id == MEI_NFC_VENDOR_INSIDE) {
 181                 if (ver->radio_type == MEI_NFC_VENDOR_INSIDE_UREAD)
 182                         return "microread";
 183         }
 184
 185         if (ver->vendor_id == MEI_NFC_VENDOR_NXP) {
 186                 if (ver->radio_type == MEI_NFC_VENDOR_NXP_PN544)
 187                         return "pn544";
 188         }
 189
 190         return NULL;
 191 }
 192
 193 /**
 194  * mei_nfc - The nfc fixup function. The function retrieves nfc radio
 195  *    name and set is as device attribute so we can load
 196  *    the proper device driver for it
 197  *
 198  * @cldev: me client device (nfc)
 199  */
 200 static void mei_nfc(struct mei_cl_device *cldev)
 201 {
 202         struct mei_device *bus;
 203         struct mei_cl *cl;
 204         struct mei_me_client *me_cl = NULL;
 205         struct mei_nfc_if_version ver;
 206         const char *radio_name = NULL;
 207         int ret;
 208
 209         bus = cldev->bus;
 210
 211         dev_dbg(bus->dev, "running hook %s: %pUl match=%d\n",
 212                 __func__, mei_me_cl_uuid(cldev->me_cl), cldev->do_match);
 213
 214         mutex_lock(&bus->device_lock);
 215         /* we need to connect to INFO GUID */
 216         cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
 217         if (IS_ERR(cl)) {
 218                 ret = PTR_ERR(cl);
 219                 cl = NULL;
 220                 dev_err(bus->dev, "nfc hook alloc failed %d\n", ret);
 221                 goto out;
 222         }
 223
 224         me_cl = mei_me_cl_by_uuid(bus, &mei_nfc_info_guid);
 225         if (!me_cl) {
 226                 ret = -ENOTTY;
 227                 dev_err(bus->dev, "Cannot find nfc info %d\n", ret);
 228                 goto out;
 229         }
 230
 231         ret = mei_cl_connect(cl, me_cl, NULL);
 232         if (ret < 0) {
 233                 dev_err(&cldev->dev, "Can't connect to the NFC INFO ME ret = %d\n",
 234                         ret);
 235                 goto out;
 236         }
 237
 238         mutex_unlock(&bus->device_lock);
 239
 240         ret = mei_nfc_if_version(cl, &ver);
 241         if (ret)
 242                 goto disconnect;
 243
 244         radio_name = mei_nfc_radio_name(&ver);
 245
 246         if (!radio_name) {
 247                 ret = -ENOENT;
 248                 dev_err(&cldev->dev, "Can't get the NFC interface version ret = %d\n",
 249                         ret);
 250                 goto disconnect;
 251         }
 252
 253         dev_dbg(bus->dev, "nfc radio %s\n", radio_name);
 254         strlcpy(cldev->name, radio_name, sizeof(cldev->name));
 255
 256 disconnect:
 257         mutex_lock(&bus->device_lock);
 258         if (mei_cl_disconnect(cl) < 0)
 259                 dev_err(bus->dev, "Can't disconnect the NFC INFO ME\n");
 260
 261         mei_cl_flush_queues(cl, NULL);
 262
 263 out:
 264         mei_cl_unlink(cl);
 265         mutex_unlock(&bus->device_lock);
 266         mei_me_cl_put(me_cl);
 267         kfree(cl);
 268
 269         if (ret)
 270                 cldev->do_match = 0;
 271
 272         dev_dbg(bus->dev, "end of fixup match = %d\n", cldev->do_match);
 273 }
 274
 275 #define MEI_FIXUP(_uuid, _hook) { _uuid, _hook }
 276
 277 static struct mei_fixup {
 278
 279         const uuid_le uuid;
 280         void (*hook)(struct mei_cl_device *cldev);
 281 } mei_fixups[] = {
 282         MEI_FIXUP(MEI_UUID_ANY, number_of_connections),
 283         MEI_FIXUP(MEI_UUID_NFC_INFO, blacklist),
 284         MEI_FIXUP(MEI_UUID_NFC_HCI, mei_nfc),
 285 };
 286
 287 /**
 288  * mei_cl_dev_fixup - run fixup handlers
 289  *
 290  * @cldev: me client device
 291  */
 292 void mei_cl_dev_fixup(struct mei_cl_device *cldev)
 293 {
 294         struct mei_fixup *f;
 295         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 296         int i;
 297
 298         for (i = 0; i < ARRAY_SIZE(mei_fixups); i++) {
 299
 300                 f = &mei_fixups[i];
 301                 if (uuid_le_cmp(f->uuid, MEI_UUID_ANY) == 0 ||
 302                     uuid_le_cmp(f->uuid, *uuid) == 0)
 303                         f->hook(cldev);
 304         }
 305 }
 306