admin管理员组文章数量:1631139
http://blog.csdn/ussam/article/details/24393267
这里使用的是ath9k网卡驱动,硬件平台是TP-link TL-WR841N V7.1 路由器
1 ath_pci_init()驱动的主入口为ath_pci_init()(位于linux-3.3.8 /drivers/net/wireless/ath/ath9k文件夹下的pci.c文件中):
int ath_pci_init(void)
{
return pci_register_driver(&ath_pci_driver);
}
可以看到ath_pci_driver作为参数传递给了pci_register_driver ()。ath_pci_driver的定义如下(位于linux-3.3.8 /drivers/net/wireless/ath/ath9k文件夹下的pci.c文件中):
static struct pci_driver ath_pci_driver = { .name = "ath9k", .id_table = ath_pci_id_table, .probe = ath_pci_probe, .remove = ath_pci_remove, .driver.pm = ATH9K_PM_OPS, };2 ath_pci_probe()
紧接着,系统会通过probe指针来调用ath_pci_probe函数(ath_pci_probe函数定义于linux-3.3.8 /drivers/net/wireless/ath/ath9k文件夹下的pci.c文件中)。
static int ath_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { … hw = ieee80211_alloc_hw(sizeof(struct ath_softc), &ath9k_ops); if (!hw) { dev_err(&pdev->dev, "No memory for ieee80211_hw\n"); ret = -ENOMEM; goto err_alloc_hw; } SET_IEEE80211_DEV(hw, &pdev->dev); pci_set_drvdata(pdev, hw); sc = hw->priv; sc->hw = hw; sc->dev = &pdev->dev; sc->mem = mem; /* Will be cleared in ath9k_start() */ sc->sc_flags |= SC_OP_INVALID; ret = request_irq(pdev->irq, ath_isr, IRQF_SHARED, "ath9k", sc); if (ret) { dev_err(&pdev->dev, "request_irq failed\n"); goto err_irq; } sc->irq = pdev->irq; ret = ath9k_init_device(id->device, sc, &ath_pci_bus_ops); if (ret) { dev_err(&pdev->dev, "Failed to initialize device\n"); goto err_init; } … }3 ieee80211_alloc_hw()
注意ath_pci_probe()函数体中的这行代码:
hw = ieee80211_alloc_hw(sizeof(struct ath_softc), &ath9k_ops);
函数ieee80211_alloc_hw()定义于OpenWRT内核文件夹子目录/net/mac80211,文件main.c中,这里传入的参数是结构体ath9k_ops, 该结构体的定义如下(位于linux-3.3.8 /drivers/net/wireless/ath/ath9k文件夹下的main.c文件中):
struct ieee80211_ops ath9k_ops = {
.tx = ath9k_tx,
.start = ath9k_start,
.stop = ath9k_stop,
.add_interface = ath9k_add_interface,
.change_interface = ath9k_change_interface,
.remove_interface = ath9k_remove_interface,
.config = ath9k_config,
.configure_filter = ath9k_configure_filter,
.sta_add = ath9k_sta_add,
.sta_remove = ath9k_sta_remove,
.sta_notify = ath9k_sta_notify,
.conf_tx = ath9k_conf_tx,
.bss_info_changed = ath9k_bss_info_changed,
.set_key = ath9k_set_key,
.get_tsf = ath9k_get_tsf,
.set_tsf = ath9k_set_tsf,
.reset_tsf = ath9k_reset_tsf,
.ampdu_action = ath9k_ampdu_action,
.get_survey = ath9k_get_survey,
.rfkill_poll = ath9k_rfkill_poll_state,
.set_coverage_class = ath9k_set_coverage_class,
.flush = ath9k_flush,
.tx_frames_pending = ath9k_tx_frames_pending,
.tx_last_beacon = ath9k_tx_last_beacon,
.get_stats = ath9k_get_stats,
.set_antenna = ath9k_set_antenna,
.get_antenna = ath9k_get_antenna,
};
将参数ath9k_ops传输ieee80211_alloc_hw()函数以后,系统将可以使用参数ath9k_ops中定义的函数指针。以tx为例,在tx.c中将会用到该函数指针。
下面再来看看ieee80211_alloc_hw()函数:
struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len, const struct ieee80211_ops *ops) { struct ieee80211_local *local; int priv_size, i; struct wiphy *wiphy; bool use_chanctx; … /* Ensure 32-byte alignment of our private data and hw private data. * We use the wiphy priv data for both our ieee80211_local and for * the driver's private data * * In memory it'll be like this: * * +-------------------------+ * | struct wiphy | * +-------------------------+ * | struct ieee80211_local | * +-------------------------+ * | driver's private data | * +-------------------------+ * */ priv_size = ALIGN(sizeof(*local), NETDEV_ALIGN) + priv_data_len; // 注意这里的mac80211_config_ops // 以其中的scan成员为例,scan时就会触发对应的函数ieee80211_scan() wiphy = wiphy_new(&mac80211_config_ops, priv_size); // 注意这里的mac80211_config_ops if (!wiphy) return NULL; … // 这里的local->ops就变成传进来的参数ath9k_ops local->ops = ops; … // 这个工作队列很重要, sw scan的情况下会schedule这个工作队列来做scan INIT_DELAYED_WORK(&local->scan_work, ieee80211_scan_work); … // 这个tasklet跟接受数据紧密相关,后面会提到 tasklet_init(&local->tasklet, ieee80211_tasklet_handler, (unsigned long) local); … return &local->hw; } EXPORT_SYMBOL(ieee80211_alloc_hw);4 ath9k_init_device()
在ath_pci_probe()的函数体中,完成了ieee80211_alloc_hw()之后的另一行重要代码就是:
ret = ath9k_init_device(id->device, sc, &ath_pci_bus_ops);
接着分析ath9k_init_device ()(位于OpenWRT内核文件夹子目录/net/mac80211,文件init.c中),观察设备的初始化过程。
int ath9k_init_device(u16 devid, struct ath_softc *sc, const struct ath_bus_ops *bus_ops) { struct ieee80211_hw *hw = sc->hw; struct ath_common *common; struct ath_hw *ah; int error = 0; struct ath_regulatory *reg; /* Bring up device */ error = ath9k_init_softc(devid, sc, bus_ops); if (error != 0) goto error_init; ah = sc->sc_ah; common = ath9k_hw_common(ah); ath9k_set_hw_capab(sc, hw); /* Initialize regulatory */ error = ath_regd_init(&common->regulatory, sc->hw->wiphy, ath9k_reg_notifier); if (error) goto error_regd; reg = &common->regulatory; /* Setup TX DMA */ error = ath_tx_init(sc, ATH_TXBUF); if (error != 0) goto error_tx; /* Setup RX DMA */ error = ath_rx_init(sc, ATH_RXBUF); if (error != 0) goto error_rx; ath9k_init_txpower_limits(sc); … error = ieee80211_register_hw(hw); if (error) goto error_register; error = ath9k_init_debug(ah); if (error) { ath_err(common, "Unable to create debugfs files\n"); goto error_world; } … }4.1 首先初始化softc
static int ath9k_init_softc(u16 devid, struct ath_softc *sc,
const struct ath_bus_ops *bus_ops)
{
…
tasklet_init(&sc->intr_tq, ath9k_tasklet, (unsigned long)sc);
tasklet_init(&sc->bcon_tasklet, ath_beacon_tasklet,
(unsigned long)sc);
…
}
在这个过程中会初始化tasklet(包括beacon帧的tasklet)
4.2 初始化数据收发存储器访问
/* Setup TX DMA */
error = ath_tx_init(sc, ATH_TXBUF);
if (error != 0)
goto error_tx;
/* Setup RX DMA */
error = ath_rx_init(sc, ATH_RXBUF);
if (error != 0)
goto error_rx;
4.3 注册设备
error = ieee80211_register_hw(hw);
至此,设备启动,驱动程序成功加载到设备上。 版权声明:本文标题:ath9K 驱动注册过程 内容由热心网友自发贡献,该文观点仅代表作者本人, 转载请联系作者并注明出处:https://m.elefans.com/dianzi/1729028481a1183511.html, 本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌抄袭侵权/违法违规的内容,一经查实,本站将立刻删除。
发表评论