ath9k网卡驱动相关

      因最近需要对ath9k的网卡驱动进行一些修改，但是网上资料比较少也比较零散，所以在这里整理一下并加上一些自己的理解，有助于自己的分析。

(1)：ath_softc是硬件与MAC层进行交互的中间载体,很多有用的

网络参数都可以从ath_softc中得到，对于进一步的网卡驱动开发，收集网络数据等很有帮助。

       定义位置：drivers/net/wireless/ath/ath9k/ath9k.h 具体定义如下：

struct ath_softc {
    struct ieee80211_hw *hw;    //保存硬件信息
    struct device *dev;         //当前工作的设备

    u32 chan_bw;                // 信道带宽
    int chan_idx;               // 信道序号
    int chan_is_ht;             // 是否使用high_throughput模式 即绿野模式
    struct survey_info *cur_survey;
    struct survey_info survey[ATH9K_NUM_CHANNELS];

    struct tasklet_struct intr_tq;   
    struct tasklet_struct bcon_tasklet;   //结构体定义在 include   用于中断管理
    struct ath_hw *sc_ah;                //hw的包装结构体
    void __iomem *mem;                   //内存区域
    int irq;
    spinlock_t sc_serial_rw;
    spinlock_t sc_pm_lock;
    spinlock_t sc_pcu_lock;             //进行数据读取，或者处理skb时需要的锁
    struct mutex mutex;
    struct work_struct paprd_work;
    struct work_struct hw_check_work;
    struct work_struct hw_reset_work;   //执行不同工作的工作队列 以后在代码中具体解释
    struct completion paprd_complete;

    unsigned int hw_busy_count;

    u32 intrstatus;
    u32 sc_flags; /* SC_OP_* */
    u16 ps_flags; /* PS_* */
    u16 curtxpow;
    bool ps_enabled;
    bool ps_idle;
    short nbcnvifs;
    short nvifs;
    unsigned long ps_usecount;

    struct ath_config config;
    struct ath_rx rx;
    struct ath_tx tx;
    struct ath_beacon beacon;
    struct ieee80211_supported_band sbands[IEEE80211_NUM_BANDS];     //当前支持的带宽

#ifdef CONFIG_MAC80211_LEDS
    const char *led_default_trigger;
    struct list_head leds;
#endif

    struct ath9k_hw_cal_data caldata;
    int last_rssi;

#ifdef CONFIG_ATH9K_DEBUGFS
    struct ath9k_debug debug;
    spinlock_t nodes_lock;
    struct list_head nodes; /* basically, stations */
    unsigned int tx_complete_poll_work_seen;
#endif
    struct ath_beacon_config cur_beacon_conf;
    struct delayed_work tx_complete_work;
    struct delayed_work hw_pll_work;
    struct ath_btcoex btcoex;
    struct ath_mci_coex mci_coex;

    struct ath_descdma txsdma;

    struct ath_ant_comb ant_comb;
    u8 ant_tx, ant_rx;
};

(2): * struct ieee80211_hw - hardware information and state
 *
 * This structure contains the configuration and hardware
 * information for an 802.11 PHY.
 *
 * @wiphy: This points to the &struct wiphy allocated for this
 * 802.11 PHY. You must fill in the @perm_addr and @dev
 * members of this structure using SET_IEEE80211_DEV()
 * and SET_IEEE80211_PERM_ADDR(). Additionally, all supported
 * bands (with channels, bitrates) are registered here.
 *
 * @conf: &struct ieee80211_conf, device configuration, don't use.
 *
 * @priv: pointer to private area that was allocated for driver use
 * along with this structure.
 *
 * @flags: hardware flags, see &enum ieee80211_hw_flags.
 *
 * @extra_tx_headroom: headroom to reserve in each transmit skb
 * for use by the driver (e.g. for transmit headers.)
 *
 * @extra_beacon_tailroom: tailroom to reserve in each beacon tx skb.
 * Can be used by drivers to add extra IEs.
 *
 * @max_signal: Maximum value for signal (rssi) in RX information, used
 * only when @IEEE80211_HW_SIGNAL_UNSPEC or @IEEE80211_HW_SIGNAL_DB
 *
 * @max_listen_interval: max listen interval in units of beacon interval
 * that HW supports
 *
 * @queues: number of available hardware transmit queues for
 * data packets. WMM/QoS requires at least four, these
 * queues need to have configurable access parameters.
 *
 * @rate_control_algorithm: rate control algorithm for this hardware.
 * If unset (NULL), the default algorithm will be used. Must be
 * set before calling ieee80211_register_hw().
 *
 * @vif_data_size: size (in bytes) of the drv_priv data area
 * within &struct ieee80211_vif.
 * @sta_data_size: size (in bytes) of the drv_priv data area
 * within &struct ieee80211_sta.
 * @chanctx_data_size: size (in bytes) of the drv_priv data area
 * within &struct ieee80211_chanctx_conf.
 * @txq_data_size: size (in bytes) of the drv_priv data area
 * within @struct ieee80211_txq.
 *
 * @max_rates: maximum number of alternate rate retry stages the hw
 * can handle.
 * @max_report_rates: maximum number of alternate rate retry stages
 * the hw can report back.
 * @max_rate_tries: maximum number of tries for each stage
 *
 * @max_rx_aggregation_subframes: maximum buffer size (number of
 * sub-frames) to be used for A-MPDU block ack receiver
 * aggregation.
 * This is only relevant if the device has restrictions on the
 * number of subframes, if it relies on mac80211 to do reordering
 * it shouldn't be set.
 *
 * @max_tx_aggregation_subframes: maximum number of subframes in an
 * aggregate an HT driver will transmit, used by the peer as a
 * hint to size its reorder buffer.
 *
 * @offchannel_tx_hw_queue: HW queue ID to use for offchannel TX
 * (if %IEEE80211_HW_QUEUE_CONTROL is set)
 *
 * @radiotap_mcs_details: lists which MCS information can the HW
 * reports, by default it is set to _MCS, _GI and _BW but doesn't
 * include _FMT. Use %IEEE80211_RADIOTAP_MCS_HAVE_* values, only
 * adding _BW is supported today.
 *
 * @radiotap_vht_details: lists which VHT MCS information the HW reports,
 * the default is _GI | _BANDWIDTH.
 * Use the %IEEE80211_RADIOTAP_VHT_KNOWN_* values.
 *
 * @netdev_features: netdev features to be set in each netdev created
 * from this HW. Note only HW checksum features are currently
 * compatible with mac80211. Other feature bits will be rejected.
 *
 * @uapsd_queues: This bitmap is included in (re)association frame to indicate
 * for each access category if it is uAPSD trigger-enabled and delivery-
 * enabled. Use IEEE80211_WMM_IE_STA_QOSINFO_AC_* to set this bitmap.
 * Each bit corresponds to different AC. Value '1' in specific bit means
 * that corresponding AC is both trigger- and delivery-enabled. '0' means
 * neither enabled.
 *
 * @uapsd_max_sp_len: maximum number of total buffered frames the WMM AP may
 * deliver to a WMM STA during any Service Period triggered by the WMM STA.
 * Use IEEE80211_WMM_IE_STA_QOSINFO_SP_* for correct values.
 *
 * @n_cipher_schemes: a size of an array of cipher schemes definitions.
 * @cipher_schemes: a pointer to an array of cipher scheme definitions
 * supported by HW.
 *
 * @txq_ac_max_pending: maximum number of frames per AC pending in all txq
 * entries for a vif.

*/

ieee80211_hw主要是硬件的信息和状态

struct ieee80211_hw {
	struct ieee80211_conf conf;
	struct wiphy *wiphy;
	const char *rate_control_algorithm;
	void *priv;
	u32 flags;
	unsigned int extra_tx_headroom;
	unsigned int extra_beacon_tailroom;
	int vif_data_size;
	int sta_data_size;
	int chanctx_data_size;
	int txq_data_size;
	u16 queues;
	u16 max_listen_interval;
	s8 max_signal;
	u8 max_rates;
	u8 max_report_rates;
	u8 max_rate_tries;
	u8 max_rx_aggregation_subframes;
	u8 max_tx_aggregation_subframes;
	u8 offchannel_tx_hw_queue;
	u8 radiotap_mcs_details;
	u16 radiotap_vht_details;
	netdev_features_t netdev_features;
	u8 uapsd_queues;
	u8 uapsd_max_sp_len;
	u8 n_cipher_schemes;
	const struct ieee80211_cipher_scheme *cipher_schemes;
	int txq_ac_max_pending;
}