linux/drivers/bluetooth/btrtl.c
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   1/*
   2 *  Bluetooth support for Realtek devices
   3 *
   4 *  Copyright (C) 2015 Endless Mobile, Inc.
   5 *
   6 *  This program is free software; you can redistribute it and/or modify
   7 *  it under the terms of the GNU General Public License as published by
   8 *  the Free Software Foundation; either version 2 of the License, or
   9 *  (at your option) any later version.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *  GNU General Public License for more details.
  15 *
  16 */
  17
  18#include <linux/module.h>
  19#include <linux/firmware.h>
  20#include <asm/unaligned.h>
  21#include <linux/usb.h>
  22
  23#include <net/bluetooth/bluetooth.h>
  24#include <net/bluetooth/hci_core.h>
  25
  26#include "btrtl.h"
  27
  28#define VERSION "0.1"
  29
  30#define RTL_EPATCH_SIGNATURE    "Realtech"
  31#define RTL_ROM_LMP_3499        0x3499
  32#define RTL_ROM_LMP_8723A       0x1200
  33#define RTL_ROM_LMP_8723B       0x8723
  34#define RTL_ROM_LMP_8821A       0x8821
  35#define RTL_ROM_LMP_8761A       0x8761
  36
  37static int rtl_read_rom_version(struct hci_dev *hdev, u8 *version)
  38{
  39        struct rtl_rom_version_evt *rom_version;
  40        struct sk_buff *skb;
  41
  42        /* Read RTL ROM version command */
  43        skb = __hci_cmd_sync(hdev, 0xfc6d, 0, NULL, HCI_INIT_TIMEOUT);
  44        if (IS_ERR(skb)) {
  45                BT_ERR("%s: Read ROM version failed (%ld)",
  46                       hdev->name, PTR_ERR(skb));
  47                return PTR_ERR(skb);
  48        }
  49
  50        if (skb->len != sizeof(*rom_version)) {
  51                BT_ERR("%s: RTL version event length mismatch", hdev->name);
  52                kfree_skb(skb);
  53                return -EIO;
  54        }
  55
  56        rom_version = (struct rtl_rom_version_evt *)skb->data;
  57        BT_INFO("%s: rom_version status=%x version=%x",
  58                hdev->name, rom_version->status, rom_version->version);
  59
  60        *version = rom_version->version;
  61
  62        kfree_skb(skb);
  63        return 0;
  64}
  65
  66static int rtl8723b_parse_firmware(struct hci_dev *hdev, u16 lmp_subver,
  67                                   const struct firmware *fw,
  68                                   unsigned char **_buf)
  69{
  70        const u8 extension_sig[] = { 0x51, 0x04, 0xfd, 0x77 };
  71        struct rtl_epatch_header *epatch_info;
  72        unsigned char *buf;
  73        int i, ret, len;
  74        size_t min_size;
  75        u8 opcode, length, data, rom_version = 0;
  76        int project_id = -1;
  77        const unsigned char *fwptr, *chip_id_base;
  78        const unsigned char *patch_length_base, *patch_offset_base;
  79        u32 patch_offset = 0;
  80        u16 patch_length, num_patches;
  81        const u16 project_id_to_lmp_subver[] = {
  82                RTL_ROM_LMP_8723A,
  83                RTL_ROM_LMP_8723B,
  84                RTL_ROM_LMP_8821A,
  85                RTL_ROM_LMP_8761A
  86        };
  87
  88        ret = rtl_read_rom_version(hdev, &rom_version);
  89        if (ret)
  90                return ret;
  91
  92        min_size = sizeof(struct rtl_epatch_header) + sizeof(extension_sig) + 3;
  93        if (fw->size < min_size)
  94                return -EINVAL;
  95
  96        fwptr = fw->data + fw->size - sizeof(extension_sig);
  97        if (memcmp(fwptr, extension_sig, sizeof(extension_sig)) != 0) {
  98                BT_ERR("%s: extension section signature mismatch", hdev->name);
  99                return -EINVAL;
 100        }
 101
 102        /* Loop from the end of the firmware parsing instructions, until
 103         * we find an instruction that identifies the "project ID" for the
 104         * hardware supported by this firwmare file.
 105         * Once we have that, we double-check that that project_id is suitable
 106         * for the hardware we are working with.
 107         */
 108        while (fwptr >= fw->data + (sizeof(struct rtl_epatch_header) + 3)) {
 109                opcode = *--fwptr;
 110                length = *--fwptr;
 111                data = *--fwptr;
 112
 113                BT_DBG("check op=%x len=%x data=%x", opcode, length, data);
 114
 115                if (opcode == 0xff) /* EOF */
 116                        break;
 117
 118                if (length == 0) {
 119                        BT_ERR("%s: found instruction with length 0",
 120                               hdev->name);
 121                        return -EINVAL;
 122                }
 123
 124                if (opcode == 0 && length == 1) {
 125                        project_id = data;
 126                        break;
 127                }
 128
 129                fwptr -= length;
 130        }
 131
 132        if (project_id < 0) {
 133                BT_ERR("%s: failed to find version instruction", hdev->name);
 134                return -EINVAL;
 135        }
 136
 137        if (project_id >= ARRAY_SIZE(project_id_to_lmp_subver)) {
 138                BT_ERR("%s: unknown project id %d", hdev->name, project_id);
 139                return -EINVAL;
 140        }
 141
 142        if (lmp_subver != project_id_to_lmp_subver[project_id]) {
 143                BT_ERR("%s: firmware is for %x but this is a %x", hdev->name,
 144                       project_id_to_lmp_subver[project_id], lmp_subver);
 145                return -EINVAL;
 146        }
 147
 148        epatch_info = (struct rtl_epatch_header *)fw->data;
 149        if (memcmp(epatch_info->signature, RTL_EPATCH_SIGNATURE, 8) != 0) {
 150                BT_ERR("%s: bad EPATCH signature", hdev->name);
 151                return -EINVAL;
 152        }
 153
 154        num_patches = le16_to_cpu(epatch_info->num_patches);
 155        BT_DBG("fw_version=%x, num_patches=%d",
 156               le32_to_cpu(epatch_info->fw_version), num_patches);
 157
 158        /* After the rtl_epatch_header there is a funky patch metadata section.
 159         * Assuming 2 patches, the layout is:
 160         * ChipID1 ChipID2 PatchLength1 PatchLength2 PatchOffset1 PatchOffset2
 161         *
 162         * Find the right patch for this chip.
 163         */
 164        min_size += 8 * num_patches;
 165        if (fw->size < min_size)
 166                return -EINVAL;
 167
 168        chip_id_base = fw->data + sizeof(struct rtl_epatch_header);
 169        patch_length_base = chip_id_base + (sizeof(u16) * num_patches);
 170        patch_offset_base = patch_length_base + (sizeof(u16) * num_patches);
 171        for (i = 0; i < num_patches; i++) {
 172                u16 chip_id = get_unaligned_le16(chip_id_base +
 173                                                 (i * sizeof(u16)));
 174                if (chip_id == rom_version + 1) {
 175                        patch_length = get_unaligned_le16(patch_length_base +
 176                                                          (i * sizeof(u16)));
 177                        patch_offset = get_unaligned_le32(patch_offset_base +
 178                                                          (i * sizeof(u32)));
 179                        break;
 180                }
 181        }
 182
 183        if (!patch_offset) {
 184                BT_ERR("%s: didn't find patch for chip id %d",
 185                       hdev->name, rom_version);
 186                return -EINVAL;
 187        }
 188
 189        BT_DBG("length=%x offset=%x index %d", patch_length, patch_offset, i);
 190        min_size = patch_offset + patch_length;
 191        if (fw->size < min_size)
 192                return -EINVAL;
 193
 194        /* Copy the firmware into a new buffer and write the version at
 195         * the end.
 196         */
 197        len = patch_length;
 198        buf = kmemdup(fw->data + patch_offset, patch_length, GFP_KERNEL);
 199        if (!buf)
 200                return -ENOMEM;
 201
 202        memcpy(buf + patch_length - 4, &epatch_info->fw_version, 4);
 203
 204        *_buf = buf;
 205        return len;
 206}
 207
 208static int rtl_download_firmware(struct hci_dev *hdev,
 209                                 const unsigned char *data, int fw_len)
 210{
 211        struct rtl_download_cmd *dl_cmd;
 212        int frag_num = fw_len / RTL_FRAG_LEN + 1;
 213        int frag_len = RTL_FRAG_LEN;
 214        int ret = 0;
 215        int i;
 216
 217        dl_cmd = kmalloc(sizeof(struct rtl_download_cmd), GFP_KERNEL);
 218        if (!dl_cmd)
 219                return -ENOMEM;
 220
 221        for (i = 0; i < frag_num; i++) {
 222                struct sk_buff *skb;
 223
 224                BT_DBG("download fw (%d/%d)", i, frag_num);
 225
 226                dl_cmd->index = i;
 227                if (i == (frag_num - 1)) {
 228                        dl_cmd->index |= 0x80; /* data end */
 229                        frag_len = fw_len % RTL_FRAG_LEN;
 230                }
 231                memcpy(dl_cmd->data, data, frag_len);
 232
 233                /* Send download command */
 234                skb = __hci_cmd_sync(hdev, 0xfc20, frag_len + 1, dl_cmd,
 235                                     HCI_INIT_TIMEOUT);
 236                if (IS_ERR(skb)) {
 237                        BT_ERR("%s: download fw command failed (%ld)",
 238                               hdev->name, PTR_ERR(skb));
 239                        ret = -PTR_ERR(skb);
 240                        goto out;
 241                }
 242
 243                if (skb->len != sizeof(struct rtl_download_response)) {
 244                        BT_ERR("%s: download fw event length mismatch",
 245                               hdev->name);
 246                        kfree_skb(skb);
 247                        ret = -EIO;
 248                        goto out;
 249                }
 250
 251                kfree_skb(skb);
 252                data += RTL_FRAG_LEN;
 253        }
 254
 255out:
 256        kfree(dl_cmd);
 257        return ret;
 258}
 259
 260static int btrtl_setup_rtl8723a(struct hci_dev *hdev)
 261{
 262        const struct firmware *fw;
 263        int ret;
 264
 265        BT_INFO("%s: rtl: loading rtl_bt/rtl8723a_fw.bin", hdev->name);
 266        ret = request_firmware(&fw, "rtl_bt/rtl8723a_fw.bin", &hdev->dev);
 267        if (ret < 0) {
 268                BT_ERR("%s: Failed to load rtl_bt/rtl8723a_fw.bin", hdev->name);
 269                return ret;
 270        }
 271
 272        if (fw->size < 8) {
 273                ret = -EINVAL;
 274                goto out;
 275        }
 276
 277        /* Check that the firmware doesn't have the epatch signature
 278         * (which is only for RTL8723B and newer).
 279         */
 280        if (!memcmp(fw->data, RTL_EPATCH_SIGNATURE, 8)) {
 281                BT_ERR("%s: unexpected EPATCH signature!", hdev->name);
 282                ret = -EINVAL;
 283                goto out;
 284        }
 285
 286        ret = rtl_download_firmware(hdev, fw->data, fw->size);
 287
 288out:
 289        release_firmware(fw);
 290        return ret;
 291}
 292
 293static int btrtl_setup_rtl8723b(struct hci_dev *hdev, u16 lmp_subver,
 294                                const char *fw_name)
 295{
 296        unsigned char *fw_data = NULL;
 297        const struct firmware *fw;
 298        int ret;
 299
 300        BT_INFO("%s: rtl: loading %s", hdev->name, fw_name);
 301        ret = request_firmware(&fw, fw_name, &hdev->dev);
 302        if (ret < 0) {
 303                BT_ERR("%s: Failed to load %s", hdev->name, fw_name);
 304                return ret;
 305        }
 306
 307        ret = rtl8723b_parse_firmware(hdev, lmp_subver, fw, &fw_data);
 308        if (ret < 0)
 309                goto out;
 310
 311        ret = rtl_download_firmware(hdev, fw_data, ret);
 312        kfree(fw_data);
 313        if (ret < 0)
 314                goto out;
 315
 316out:
 317        release_firmware(fw);
 318        return ret;
 319}
 320
 321static struct sk_buff *btrtl_read_local_version(struct hci_dev *hdev)
 322{
 323        struct sk_buff *skb;
 324
 325        skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
 326                             HCI_INIT_TIMEOUT);
 327        if (IS_ERR(skb)) {
 328                BT_ERR("%s: HCI_OP_READ_LOCAL_VERSION failed (%ld)",
 329                       hdev->name, PTR_ERR(skb));
 330                return skb;
 331        }
 332
 333        if (skb->len != sizeof(struct hci_rp_read_local_version)) {
 334                BT_ERR("%s: HCI_OP_READ_LOCAL_VERSION event length mismatch",
 335                       hdev->name);
 336                kfree_skb(skb);
 337                return ERR_PTR(-EIO);
 338        }
 339
 340        return skb;
 341}
 342
 343int btrtl_setup_realtek(struct hci_dev *hdev)
 344{
 345        struct sk_buff *skb;
 346        struct hci_rp_read_local_version *resp;
 347        u16 lmp_subver;
 348
 349        skb = btrtl_read_local_version(hdev);
 350        if (IS_ERR(skb))
 351                return -PTR_ERR(skb);
 352
 353        resp = (struct hci_rp_read_local_version *)skb->data;
 354        BT_INFO("%s: rtl: examining hci_ver=%02x hci_rev=%04x lmp_ver=%02x "
 355                "lmp_subver=%04x", hdev->name, resp->hci_ver, resp->hci_rev,
 356                resp->lmp_ver, resp->lmp_subver);
 357
 358        lmp_subver = le16_to_cpu(resp->lmp_subver);
 359        kfree_skb(skb);
 360
 361        /* Match a set of subver values that correspond to stock firmware,
 362         * which is not compatible with standard btusb.
 363         * If matched, upload an alternative firmware that does conform to
 364         * standard btusb. Once that firmware is uploaded, the subver changes
 365         * to a different value.
 366         */
 367        switch (lmp_subver) {
 368        case RTL_ROM_LMP_8723A:
 369        case RTL_ROM_LMP_3499:
 370                return btrtl_setup_rtl8723a(hdev);
 371        case RTL_ROM_LMP_8723B:
 372                return btrtl_setup_rtl8723b(hdev, lmp_subver,
 373                                            "rtl_bt/rtl8723b_fw.bin");
 374        case RTL_ROM_LMP_8821A:
 375                return btrtl_setup_rtl8723b(hdev, lmp_subver,
 376                                            "rtl_bt/rtl8821a_fw.bin");
 377        case RTL_ROM_LMP_8761A:
 378                return btrtl_setup_rtl8723b(hdev, lmp_subver,
 379                                            "rtl_bt/rtl8761a_fw.bin");
 380        default:
 381                BT_INFO("rtl: assuming no firmware upload needed.");
 382                return 0;
 383        }
 384}
 385EXPORT_SYMBOL_GPL(btrtl_setup_realtek);
 386
 387MODULE_AUTHOR("Daniel Drake <drake@endlessm.com>");
 388MODULE_DESCRIPTION("Bluetooth support for Realtek devices ver " VERSION);
 389MODULE_VERSION(VERSION);
 390MODULE_LICENSE("GPL");
 391