RLT USB WiFi驱动源码分析(Type A)

USB WiFi驱动属于USB设备驱动，底层是USB主机控制器驱动。USB主机控制器驱动根据USB协议向USB设备驱动提供读写接口。USB WiFi驱动根据USB主机控制器驱动提供的读写接口对USB WiFi网卡进行寄存器设置、数据收发。

Kernel

WiFi/os_dep

WiFi/core

WiFi/hal

USB/core

Hardware

core/：802.11协议相关功能文件（隔离硬件和OS）

hal/：硬件相关文件

os_dep/：OS相关文件

关键点：

1. 启动一个CMD内核线程；

2. 使用tasklet处理接收和发送；

hostapd在启动时，通过ioctl设置网卡参数，如设置beacan参数后，硬件自动发生beacon帧。

当ifconfig wlan0 up时，wlan0调用open() => netdev_open()

【数据结构】

struct net_device

void *priv = struct rtw_netdev_priv_indicator

void *priv = struct _ADAPTER

struct _ADAPTER

struct hal_ops HalFunc

struct dvobj_priv dvobjpriv

struct mlme_priv mlmepriv

struct mlme_ext_priv mlmeextpriv

struct cmd_priv cmdpriv

struct evt_priv evtpriv

struct io_priv iopriv

struct xmit_priv xmitpriv

struct recv_priv recvpriv

struct sta_priv stapriv

struct security_priv securitypriv

struct registry_priv registrypriv

struct hostapd_priv *phostapdpriv

struct wifidirect_info wdinfo

【驱动加载】

module_init(rtw_drv_entry)

usb_register(&drvpriv.rtw_usb_drv)

static drv_priv drvpriv.rtw_usb_drv.probe = rtw_drv_init

rtw_drv_init(struct usb_interface *pusb_intf, const struct usb_device_id *pdid)

pnetdev = rtw_init_netdev(NULL)

pnetdev = rtw_alloc_etherdev(sizeof(_adapter))  /* 申请net_device和priv(即_adapter)内存 */

pnetdev = alloc_etherdev(sizeof(struct rtw_netdev_priv_indicator))

alloc_netdev(sizeof(struct rtw_netdev_priv_indicator), "eth%d", ether_setup)   /* 申请net_device内存*/

pnpi = netdev_priv(pnetdev)   /* priv = struct rtw_netdev_priv_indicator */

pnpi->priv = rtw_zvmalloc(sizeof_priv)   /* 申请_adapter内存 */

pnpi->sizeof_priv=sizeof_priv

padapter = rtw_netdev_priv(pnetdev)  /* 获取adapter地址 */

padapter->pnetdev = pnetdev

pnetdev->open = netdev_open        /* 应用层打开设备 */

pnetdev->hard_start_xmit = rtw_xmit_entry

pnetdev->do_ioctl = rtw_ioctl       /* 应用层ioctl */

loadparam(padapter, pnetdev)      /* 设置adapter基本参数 */

padapter = rtw_netdev_priv(pnetdev)      /* 获取adapter地址 */

pdvobjpriv = &padapter->dvobjpriv

/* 

设置usb相关hal接口函数hal/rtl8192d/usb/usb_halinit.c    

*/

rtl8192du_set_hal_ops(padapter)

pHalFunc->hal_init = &rtl8192du_hal_init   /* HAL初始化 */

pHalFunc->init_xmit_priv = &rtl8192du_init_xmit_priv   /* 发生priv初始化 */

pHalFunc->init_recv_priv = &rtl8192du_init_recv_priv   /* 接收priv初始化 */

/*

设置usb无关hal接口函数hal/rtl8192d/rtl8192d_hal_init.c

*/

rtl8192d_set_hal_ops(pHalFunc)

padapter->dvobj_init=&usb_dvobj_init

padapter->intf_start=&usb_intf_start

status = padapter->dvobj_init(padapter) => usb_dvobj_init()

rtw_init_io_priv(padapter)

/* 

设置usb读写接口函数hal/rtl8192d/usb/usb_ops_linux.c

*/

rtl8192du_set_intf_ops(&pintf->io_ops)

pops->_read8 = &usb_read8

pops->_read_port = &usb_read_port

pops->_write8 = &usb_write8

pops->_write_port = &usb_write_port

rtw_init_intf_priv(padapter)

intf_read_chip_info(padapter)  /* 读取efuse/eeprom数据和MAC地址 */

padapter->HalFunc.read_adapter_info(padapter) => ReadAdapterInfo8192DU() => _ReadAdapterInfo8192DU()

_ReadRFType(Adapter)  /* 读常量 */

_ReadPROMContent(Adapter)   /* 读寄存器  */

_InitOtherVariable(Adapter)

/*

初始化各个priv结构

*/

status = rtw_init_drv_sw(padapter)

rtw_init_cmd_priv(&padapter->cmdpriv) => _rtw_init_cmd_priv (pcmdpriv)

_rtw_init_sema(&(pcmdpriv->cmd_queue_sema), 0) => sema_init(sema, init_val)

_rtw_init_sema(&(pcmdpriv->terminate_cmdthread_sema), 0)

_rtw_init_queue(&(pcmdpriv->cmd_queue))

pcmdpriv->cmd_buf = ...   /* 申请buffer内存 */

pcmdpriv->rsp_buf = ... /* 申请buffer内存 */

rtw_init_evt_priv(&padapter->evtpriv) => _rtw_init_evt_priv(pevtpriv)

//_rtw_init_queue(&(pevtpriv->evt_queue))

rtw_init_mlme_priv(padapter) => _rtw_init_mlme_priv(padapter)

_rtw_init_queue(&(pmlmepriv->free_bss_pool))

_rtw_init_queue(&(pmlmepriv->scanned_queue))

pmlmepriv->free_bss_buf = rtw_zvmalloc(MAX_BSS_CNT * (sizeof(struct wlan_network)))

rtw_init_mlme_timer(padapter)

_init_timer(&(pmlmepriv->assoc_timer), padapter->pnetdev, rtw_join_timeout_handler, padapter)

_init_timer(&(pmlmepriv->scan_to_timer), padapter->pnetdev, _rtw_scan_timeout_handler, padapter)

init_mlme_ext_priv(padapter)

init_mlme_ext_priv_value(padapter)

init_mlme_ext_timer(padapter)

init_mlme_ap_info(padapter)

start_ap_mode(padapter)

init_channel_set()

init_channel_list()

_rtw_init_xmit_priv(&padapter->xmitpriv, padapter)

/* 

初始化发送tasklet

*/

padapter->HalFunc.init_xmit_priv(padapter) => rtl8192du_init_xmit_priv()

tasklet_init(&pxmitpriv->xmit_tasklet,rtl8192du_xmit_tasklet,padapter)

_rtw_init_recv_priv(&padapter->recvpriv, padapter)

/*

初始化接收tasklet

*/

padapter->HalFunc.init_recv_priv(padapter) => rtl8192du_init_recv_priv()

tasklet_init(&precvpriv->recv_tasklet,rtl8192du_recv_tasklet,padapter)

_rtw_init_sta_priv(&padapter->stapriv)

rtw_init_netdev_name(pnetdev, ifname)

//hostapd_mode_init(padapter)

register_netdev(pnetdev)  /* 向内核注册网络设备 */

rtw_drv_if2_init(padapter, NULL)

【启动open】

netdev_open(struct net_device *pnetdev)

rtw_hal_init(padapter)

padapter->HalFunc.hal_deinit(padapter)

padapter->HalFunc.hal_init(padapter)

rtw_start_drv_threads(padapter)

/* 

启动CMD线程 

*/

padapter->cmdThread = kernel_thread(rtw_cmd_thread, padapter, CLONE_FS|CLONE_FILES)

init_hw_mlme_ext(padapter) 

set_channel_bwmode() 

padapter->HalFunc.set_channel_handler(padapter, center_ch)

SetBWMode(padapter, bwmode, channel_offset)

padapter->HalFunc.set_bwmode_handler()

padapter->intf_start(padapter) => usb_intf_start()

padapter->HalFunc.inirp_init(padapter) => rtl8192du_inirp_init()

pintfhdl->io_ops._read_port() => usb_read_port()  /* hal/8192d/usb/usb_ops_linux.c */

rtl8192du_init_recvbuf(adapter, precvbuf)

pipe = ffaddr2pipehdl(pdvobj, addr)

usb_fill_bulk_urb(purb, pusbd, pipe, precvbuf->pbuf, MAX_RECVBUF_SZ, usb_read_port_complete, precvbuf)

usb_submit_urb(purb, GFP_ATOMIC)

【接收】

usb读到数据后，调用usb_read_port_complete():

usb_read_port_complete()

tasklet_schedule(&precvpriv->recv_tasklet)   /* 启动tasklet执行后续任务 */

rtl8192du_recv_tasklet()

pskb = skb_dequeue(&precvpriv->rx_skb_queue)

recvbuf2recvframe(padapter, pskb)

rtw_recv_entry(precvframe)

recv_func(padapter, precvframe)

retval = validate_recv_frame(padapter, prframe)

switch (type)

case WIFI_MGT_TYPE: validate_recv_mgnt_frame(adapter, precv_frame)

case WIFI_CTRL_TYPE: validate_recv_ctrl_frame(adapter, precv_frame)

case WIFI_DATA_TYPE: validate_recv_data_frame(adapter, precv_frame)

rtw_read_port(padapter, precvpriv->ff_hwaddr, 0, (unsigned char *)precvbuf)  /* 继续读usb */

【发送】

【控制ioctl】

rtw_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)

switch (cmd)

case RTL_IOCTL_WPA_SUPPLICANT

wpa_supplicant_ioctl(dev, &wrq->u.data)

case RTL_IOCTL_HOSTAPD

rtw_hostapd_ioctl(dev, &wrq->u.data)

param = (struct ieee_param *)rtw_malloc(p->length)

copy_from_user(param, p->pointer, p->length)

switch (param->cmd)

case RTL871X_HOSTAPD_SET_BEACON

rtw_set_beacon(dev, param, p->length)

start_bss_network(padapter, (u8*)pbss_network)

update_beacon(padapter, _TIM_IE_, NULL, _FALSE)

update_BCNTIM(padapter)

set_tx_beacon_cmd(padapter)

init_h2fwcmd_w_parm_no_rsp(ph2c, ptxBeacon_parm, GEN_CMD_CODE(_TX_Beacon))

rtw_enqueue_cmd(pcmdpriv, ph2c)

send_beacon(padapter)

issue_beacon(padapter)

dump_mgntframe(padapter, pmgntframe)

padapter->HalFunc.GetHwRegHandler(padapter, HW_VAR_TX_BCN_DONE, (u8 *)(&bxmitok))

update_bmc_sta(padapter)