drivers/bluetooth/btrtl.c

   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
  37 static 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
  66 static 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
 208 static 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
 255 out:
 256         kfree(dl_cmd);
 257         return ret;
 258 }
 259
 260 static 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
 288 out:
 289         release_firmware(fw);
 290         return ret;
 291 }
 292
 293 static 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
 316 out:
 317         release_firmware(fw);
 318         return ret;
 319 }
 320
 321 static 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
 343 int 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 }
 385 EXPORT_SYMBOL_GPL(btrtl_setup_realtek);
 386
 387 MODULE_AUTHOR("Daniel Drake <drake@endlessm.com>");
 388 MODULE_DESCRIPTION("Bluetooth support for Realtek devices ver " VERSION);
 389 MODULE_VERSION(VERSION);
 390 MODULE_LICENSE("GPL");