xref: /btstack/chipset/realtek/btstack_chipset_realtek.c (revision 8bb555aa6b09e3f91bb7caaba1c7b6db6ac22e10)

/*
 * Copyright (C) 2014 BlueKitchen GmbH
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 * 4. Any redistribution, use, or modification is done solely for
 *    personal benefit and not for any commercial purpose or for
 *    monetary gain.
 *
 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
 * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Please inquire about commercial licensing options at
 * [email protected]
 *
 */

#define BTSTACK_FILE__ "btstack_chipset_realtek.c"

/*
 *  btstack_chipset_realtek.c
 *
 *  Adapter to use REALTEK-based chipsets with BTstack
 */

#include "btstack_chipset_realtek.h"

#include <stddef.h> /* NULL */
#include <stdio.h>
#include <string.h> /* memcpy */

#include "btstack_control.h"
#include "btstack_debug.h"
#include "btstack_event.h"
#include "btstack_util.h"
#include "hci.h"
#include "hci_transport.h"

#define ROM_LMP_NONE 0x0000
#define ROM_LMP_8723a 0x1200
#define ROM_LMP_8723b 0x8723
#define ROM_LMP_8821a 0X8821
#define ROM_LMP_8761a 0X8761
#define ROM_LMP_8822b 0X8822

#define HCI_DOWNLOAD_FW 0xFC20
#define HCI_READ_ROM_VERSION 0xFC6D
#define HCI_READ_LMP_VERSION 0x1001
#define HCI_RESET 0x0C03

#define FILL_COMMAND(buf, command) ((int16_t *)buf)[0] = command
#define FILL_LENGTH(buf, length) buf[2] = length
#define FILL_INDEX(buf, index) buf[3] = index
#define FILL_FW_DATA(buf, firmware, ptr, len) memcpy(buf + 4, firmware + ptr, len)

enum {
    STATE_READ_ROM_VERSION,
    STATE_LOAD_FIRMWARE,
    STATE_RESET,
    STATE_DONE,
};

enum { FW_DONE, FW_MORE_TO_DO };

typedef struct {
    uint16_t prod_id;
    uint16_t lmp_sub;
    char *   mp_patch_name;
    char *   patch_name;
    char *   config_name;

    uint8_t *fw_cache1;
    int      fw_len1;
} patch_info;

static patch_info fw_patch_table[] = {
    /* { pid, lmp_sub, mp_fw_name, fw_name, config_name, fw_cache, fw_len } */
    {0x1724, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* RTL8723A */
    {0x8723, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* 8723AE */
    {0xA723, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* 8723AE for LI */
    {0x0723, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* 8723AE */
    {0x3394, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* 8723AE for Azurewave */

    {0x0724, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* 8723AU */
    {0x8725, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* 8723AU */
    {0x872A, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* 8723AU */
    {0x872B, 0x1200, "mp_rtl8723a_fw", "rtl8723a_fw", "rtl8723a_config", NULL, 0}, /* 8723AU */

    {0xb720, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723bu_config", NULL, 0}, /* RTL8723BU */
    {0xb72A, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723bu_config", NULL, 0}, /* RTL8723BU */
    {0xb728, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0},  /* RTL8723BE for LC */
    {0xb723, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0},  /* RTL8723BE */
    {0xb72B, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0},  /* RTL8723BE */
    {0xb001, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0},  /* RTL8723BE for HP */
    {0xb002, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0},  /* RTL8723BE */
    {0xb003, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0},  /* RTL8723BE */
    {0xb004, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0},  /* RTL8723BE */
    {0xb005, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0},  /* RTL8723BE */

    {0x3410, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0}, /* RTL8723BE for Azurewave */
    {0x3416, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0}, /* RTL8723BE for Azurewave */
    {0x3459, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0}, /* RTL8723BE for Azurewave */
    {0xE085, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0}, /* RTL8723BE for Foxconn */
    {0xE08B, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0}, /* RTL8723BE for Foxconn */
    {0xE09E, 0x8723, "mp_rtl8723b_fw", "rtl8723b_fw", "rtl8723b_config", NULL, 0}, /* RTL8723BE for Foxconn */

    {0xA761, 0x8761, "mp_rtl8761a_fw", "rtl8761au_fw", "rtl8761a_config", NULL, 0},  /* RTL8761AU only */
    {0x818B, 0x8761, "mp_rtl8761a_fw", "rtl8761aw_fw", "rtl8761aw_config", NULL, 0}, /* RTL8761AW + 8192EU */
    {0x818C, 0x8761, "mp_rtl8761a_fw", "rtl8761aw_fw", "rtl8761aw_config", NULL, 0}, /* RTL8761AW + 8192EU */
    {0x8760, 0x8761, "mp_rtl8761a_fw", "rtl8761au_fw", "rtl8761a_config", NULL, 0},  /* RTL8761AU + 8192EE */
    {0xB761, 0x8761, "mp_rtl8761a_fw", "rtl8761au_fw", "rtl8761a_config", NULL, 0},  /* RTL8761AU + 8192EE */
    {0x8761, 0x8761, "mp_rtl8761a_fw", "rtl8761au_fw", "rtl8761a_config", NULL, 0},  /* RTL8761AU + 8192EE for LI */
    {0x8A60, 0x8761, "mp_rtl8761a_fw", "rtl8761au_fw", "rtl8761a_config", NULL, 0},  /* RTL8761AU + 8812AE */
    {0x3527, 0x8761, "mp_rtl8761a_fw", "rtl8761au_fw", "rtl8761a_config", NULL, 0},  /* RTL8761AU + 8814AE */

    {0x8821, 0x8821, "mp_rtl8821a_fw", "rtl8821a_fw", "rtl8821a_config", NULL, 0}, /* RTL8821AE */
    {0x0821, 0x8821, "mp_rtl8821a_fw", "rtl8821a_fw", "rtl8821a_config", NULL, 0}, /* RTL8821AE */
    {0x0823, 0x8821, "mp_rtl8821a_fw", "rtl8821a_fw", "rtl8821a_config", NULL, 0}, /* RTL8821AU */
    {0x3414, 0x8821, "mp_rtl8821a_fw", "rtl8821a_fw", "rtl8821a_config", NULL, 0}, /* RTL8821AE */
    {0x3458, 0x8821, "mp_rtl8821a_fw", "rtl8821a_fw", "rtl8821a_config", NULL, 0}, /* RTL8821AE */
    {0x3461, 0x8821, "mp_rtl8821a_fw", "rtl8821a_fw", "rtl8821a_config", NULL, 0}, /* RTL8821AE */
    {0x3462, 0x8821, "mp_rtl8821a_fw", "rtl8821a_fw", "rtl8821a_config", NULL, 0}, /* RTL8821AE */

    {0xb82c, 0x8822, "mp_rtl8822bu_fw", "rtl8822bu_fw", "rtl8822bu_config", NULL, 0}, /* RTL8822BU */
    {0xd723, 0x8723, "mp_rtl8723du_fw", "rtl8723du_fw", "rtl8723du_config", NULL, 0}, /* RTL8723DU */
    {0xb820, 0x8821, "mp_rtl8821cu_fw", "rtl8821cu_fw", "rtl8821cu_config", NULL, 0}, /* RTL8821CU */
    {0xc820, 0x8821, "mp_rtl8821cu_fw", "rtl8821cu_fw", "rtl8821cu_config", NULL, 0}, /* RTL8821CU */

    {0xc82c, 0x8822, "mp_rtl8822cu_fw", "rtl8822cu_fw", "rtl8822cu_config", NULL, 0}, /* RTL8822CU */
    {0xc822, 0x8822, "mp_rtl8822cu_fw", "rtl8822cu_fw", "rtl8822cu_config", NULL, 0}, /* RTL8822CE */
    {0xb00c, 0x8822, "mp_rtl8822cu_fw", "rtl8822cu_fw", "rtl8822cu_config", NULL, 0}, /* RTL8822CE */
    {0xc123, 0x8822, "mp_rtl8822cu_fw", "rtl8822cu_fw", "rtl8822cu_config", NULL, 0}, /* RTL8822CE */
    {0x3549, 0x8822, "mp_rtl8822cu_fw", "rtl8822cu_fw", "rtl8822cu_config", NULL, 0}, /* RTL8822CE for Azurewave */

    {0x8771, 0x8761, "mp_rtl8761bu_fw", "rtl8761bu_fw", "rtl8761bu_config", NULL, 0}, /* RTL8761BU only */

    /* NOTE: must append patch entries above the null entry */
    {0, 0, NULL, NULL, NULL, NULL, 0}};

uint16_t project_id[] = {
    ROM_LMP_8723a, ROM_LMP_8723b, ROM_LMP_8821a, ROM_LMP_8761a, ROM_LMP_NONE,
    ROM_LMP_NONE,  ROM_LMP_NONE,  ROM_LMP_NONE,  ROM_LMP_8822b, ROM_LMP_8723b, /* RTL8723DU */
    ROM_LMP_8821a,                                                             /* RTL8821CU */
    ROM_LMP_NONE,  ROM_LMP_NONE,  ROM_LMP_8822b,                               /* RTL8822CU */
    ROM_LMP_8761a,                                                             /* index 14 for 8761BU */
};

static btstack_packet_callback_registration_t hci_event_callback_registration;
static uint8_t                                state = STATE_READ_ROM_VERSION;
static uint8_t                                rom_version;
static uint16_t                               lmp_subversion;
static uint16_t                               product_id;
static patch_info *                           patch;

#ifdef HAVE_POSIX_FILE_IO
static const char *firmware_folder_path = ".";
static const char *firmware_file_path;
static const char *config_folder_path = ".";
static const char *config_file_path;
static char        firmware_file[1000];
static char        config_file[1000];
#endif

const uint8_t FW_SIGNATURE[8]        = {0x52, 0x65, 0x61, 0x6C, 0x74, 0x65, 0x63, 0x68};
const uint8_t EXTENSION_SIGNATURE[4] = {0x51, 0x04, 0xFD, 0x77};

static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
    UNUSED(channel);
    UNUSED(size);
    if (packet_type != HCI_EVENT_PACKET || hci_event_packet_get_type(packet) != HCI_EVENT_COMMAND_COMPLETE) {
        return;
    }
    uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);

    switch (opcode) {
    case HCI_READ_ROM_VERSION:
        rom_version = hci_event_command_complete_get_return_parameters(packet)[1];
        log_info("Received ROM version 0x%02x", rom_version);
        break;
    default:
        break;
    }
}

static void chipset_init(const void *config) {
    UNUSED(config);
#ifdef HAVE_POSIX_FILE_IO
    // determine file path
    if (firmware_file_path == NULL || config_file_path == NULL) {
        log_info("firmware or config file path is empty. Using product id 0x%04x!", product_id);
        patch = NULL;
        for (int i = 0; i < sizeof(fw_patch_table) / sizeof(patch_info); i++) {
            if (fw_patch_table[i].prod_id == product_id) {
                patch = &fw_patch_table[i];
                break;
            }
        }
        if (patch == NULL) {
            log_info("Product id 0x%04x is unknown", product_id);
            state = STATE_DONE;
            return;
        }
        sprintf(firmware_file, "%s/%s", firmware_folder_path, patch->patch_name);
        sprintf(config_file, "%s/%s", config_folder_path, patch->config_name);
        firmware_file_path = &firmware_file[0];
        config_file_path   = &config_file[0];
        lmp_subversion     = patch->lmp_sub;
    }
    log_info("Using firmware '%s' and config '%s'", firmware_file_path, config_file_path);

    // activate hci callback
    hci_event_callback_registration.callback = &hci_packet_handler;
    hci_add_event_handler(&hci_event_callback_registration);
    state = STATE_READ_ROM_VERSION;
#endif
}

#ifdef HAVE_POSIX_FILE_IO

/**
 * @brief Opens the specified file and stores content to an allocated buffer
 *
 * @param file
 * @param buf
 * @param name
 * @return uint32_t Length of file
 */
static uint32_t read_file(FILE **file, uint8_t **buf, const char *name) {
    uint32_t size;

    // open file
    *file = fopen(name, "rb");
    if (*file == NULL) {
        log_info("Failed to open file %s", name);
        return 0;
    }

    // determine length of file
    fseek(*file, 0, SEEK_END);
    size = ftell(*file);
    fseek(*file, 0, SEEK_SET);
    if (size <= 0) {
        return 0;
    }

    // allocate memory
    *buf = malloc(size);
    if (*buf == NULL) {
        fclose(*file);
        *file = NULL;
        log_info("Failed to allocate %u bytes for file %s", size, name);
        return 0;
    }

    // read file
    uint8_t ret = fread(*buf, size, 1, *file);
    if (ret != 1) {
        log_info("Failed to read %u bytes from file %s (ret = %u)", size, name, ret);
        fclose(*file);
        free(*buf);
        *file = NULL;
        *buf  = NULL;
        return 0;
    }

    log_info("Opened file %s and read %u bytes", name, size);
    return size;
}

static void finalize_file_and_buffer(FILE **file, uint8_t **buffer) {
    fclose(*file);
    free(*buffer);
    *buffer = NULL;
    *file   = NULL;
}

static uint8_t update_firmware(const char *firmware, const char *config, uint8_t *hci_cmd_buffer) {
    static uint8_t *patch_buf = NULL;
    static uint32_t fw_total_len;
    static uint32_t fw_ptr;
    static uint8_t  index;

    // read firmware and config
    if (patch_buf == NULL) {
        uint16_t patch_length = 0;
        uint32_t offset;
        FILE *   fw = NULL;
        uint32_t fw_size;
        uint8_t *fw_buf = NULL;

        FILE *   conf = NULL;
        uint32_t conf_size;
        uint8_t *conf_buf = NULL;

        if (firmware == NULL || config == NULL) {
            log_info("Please specify realtek firmware and config file paths");
            return FW_DONE;
        }

        // read firmware
        fw_size = read_file(&fw, &fw_buf, firmware);
        if (fw_size == 0) {
            log_info("Firmware size is 0. Quit!");
            return FW_DONE;
        }

        // read config
        conf_size = read_file(&conf, &conf_buf, config);
        if (conf_size == 0) {
            log_info("Config size is 0. Quit!");
            fclose(fw);
            free(fw_buf);
            fw_buf = NULL;
            fw     = NULL;
            return FW_DONE;
            finalize_file_and_buffer(&fw, &fw_buf);
        }

        // check signature
        if (memcmp(fw_buf, FW_SIGNATURE, 8) != 0 || memcmp(fw_buf + fw_size - 4, EXTENSION_SIGNATURE, 4) != 0) {
            log_info("Wrong signature. Quit!");
            finalize_file_and_buffer(&fw, &fw_buf);
            finalize_file_and_buffer(&conf, &conf_buf);
            return FW_DONE;
        }

        // check project id
        if (lmp_subversion != project_id[*(fw_buf + fw_size - 7)]) {
            log_info("Wrong project id. Quit!");
            finalize_file_and_buffer(&fw, &fw_buf);
            finalize_file_and_buffer(&conf, &conf_buf);
            return FW_DONE;
        }

        // read firmware version
        uint32_t fw_version = little_endian_read_32(fw_buf, 8);
        log_info("Firmware version: 0x%x", fw_version);

        // read number of patches
        uint16_t fw_num_patches = little_endian_read_16(fw_buf, 12);
        log_info("Number of patches: %d", fw_num_patches);

        // find correct entry
        for (uint16_t i = 0; i < fw_num_patches; i++) {
            if (little_endian_read_16(fw_buf, 14 + 2 * i) == rom_version + 1) {
                patch_length = little_endian_read_16(fw_buf, 14 + 2 * fw_num_patches + 2 * i);
                offset       = little_endian_read_32(fw_buf, 14 + 4 * fw_num_patches + 4 * i);
                log_info("patch_length %u, offset %u", patch_length, offset);
                break;
            }
        }
        if (patch_length == 0) {
            log_debug("Failed to find valid patch");
            finalize_file_and_buffer(&fw, &fw_buf);
            finalize_file_and_buffer(&conf, &conf_buf);
            return FW_DONE;
        }

        // allocate patch buffer
        fw_total_len = patch_length + conf_size;
        patch_buf    = malloc(fw_total_len);
        if (patch_buf == NULL) {
            log_debug("Failed to allocate %u bytes for patch buffer", fw_total_len);
            finalize_file_and_buffer(&fw, &fw_buf);
            finalize_file_and_buffer(&conf, &conf_buf);
            return FW_DONE;
        }

        // copy patch
        memcpy(patch_buf, fw_buf + offset, patch_length);
        memcpy(patch_buf + patch_length - 4, &fw_version, 4);
        memcpy(patch_buf + patch_length, conf_buf, conf_size);
        fw_ptr = 0;
        index  = 0;

        // close files
        finalize_file_and_buffer(&fw, &fw_buf);
        finalize_file_and_buffer(&conf, &conf_buf);
    }

    uint8_t len;
    if (fw_total_len - fw_ptr > 252) {
        len = 252;
    } else {
        len = fw_total_len - fw_ptr;
        index |= 0x80;  // end
    }

    if (len) {
        FILL_COMMAND(hci_cmd_buffer, HCI_DOWNLOAD_FW);
        FILL_LENGTH(hci_cmd_buffer, len + 1);
        FILL_INDEX(hci_cmd_buffer, index);
        FILL_FW_DATA(hci_cmd_buffer, patch_buf, fw_ptr, len);
        index++;
        fw_ptr += len;
        return FW_MORE_TO_DO;
    }

    // cleanup and return
    free(patch_buf);
    patch_buf = NULL;
    return FW_DONE;
}

#endif  // HAVE_POSIX_FILE_IO

static btstack_chipset_result_t chipset_next_command(uint8_t *hci_cmd_buffer) {
#ifdef HAVE_POSIX_FILE_IO
    uint8_t ret;
    while (true) {
        switch (state) {
        case STATE_READ_ROM_VERSION:
            FILL_COMMAND(hci_cmd_buffer, HCI_READ_ROM_VERSION);
            FILL_LENGTH(hci_cmd_buffer, 0);
            state = STATE_LOAD_FIRMWARE;
            break;
        case STATE_LOAD_FIRMWARE:
            if (lmp_subversion != ROM_LMP_8723a) {
                ret = update_firmware(firmware_file_path, config_file_path, hci_cmd_buffer);
            } else {
                log_info("Realtek firmware for old patch style not implemented");
                ret = FW_DONE;
            }
            if (ret != FW_DONE) {
                break;
            }
            // we are done fall through
            state = STATE_RESET;
        case STATE_RESET:
            FILL_COMMAND(hci_cmd_buffer, HCI_RESET);
            FILL_LENGTH(hci_cmd_buffer, 0);
            state = STATE_DONE;
            break;
        case STATE_DONE:
            hci_remove_event_handler(&hci_event_callback_registration);
            return BTSTACK_CHIPSET_DONE;
            break;
        default:
            log_info("Invalid state %d", state);
            return BTSTACK_CHIPSET_DONE;
            break;
        }
        return BTSTACK_CHIPSET_VALID_COMMAND;
    }
#else   // HAVE_POSIX_FILE_IO
    log_info("Realtek without File IO is not implemented yet");
    return BTSTACK_CHIPSET_NO_INIT_SCRIPT;
#endif  // HAVE_POSIX_FILE_IO
}

void btstack_chipset_realtek_set_firmware_file_path(const char *path) {
#ifdef HAVE_POSIX_FILE_IO
    firmware_file_path = path;
#endif
}

void btstack_chipset_realtek_set_firmware_folder_path(const char *path) {
#ifdef HAVE_POSIX_FILE_IO
    firmware_folder_path = path;
#endif
}

void btstack_chipset_realtek_set_config_file_path(const char *path) {
#ifdef HAVE_POSIX_FILE_IO
    config_file_path = path;
#endif
}

void btstack_chipset_realtek_set_config_folder_path(const char *path) {
#ifdef HAVE_POSIX_FILE_IO
    config_folder_path = path;
#endif
}

void btstack_chipset_realtek_set_lmp_subversion(uint16_t version) { lmp_subversion = version; }

void btstack_chipset_realtek_set_product_id(uint16_t id) { product_id = id; }

static const btstack_chipset_t btstack_chipset_realtek = {
    "REALTEK", chipset_init, chipset_next_command,
    NULL,  // chipset_set_baudrate_command,
    NULL,  // chipset_set_bd_addr_command not supported or implemented
};

// MARK: public API
const btstack_chipset_t *btstack_chipset_realtek_instance(void) { return &btstack_chipset_realtek; }