hci_uart 分析

先从初始化开始

__init hci_uart_init(void)

｛

……    //注册ldisc

        hci_uart_ldisc.magic = TTY_LDISC_MAGIC;    //通过i = N_HCI; if (ioctl(fd,  TIOCSETD, &i) < 0)获得

        hci_uart_ldisc.name = "n_hci";

        hci_uart_ldisc.open = hci_uart_tty_open;

        hci_uart_ldisc.close = hci_uart_tty_close;

        hci_uart_ldisc.read = hci_uart_tty_read;

        hci_uart_ldisc.write = hci_uart_tty_write;

        hci_uart_ldisc.ioctl = hci_uart_tty_ioctl;

        hci_uart_ldisc.poll = hci_uart_tty_poll;

        hci_uart_ldisc.receive_buf = hci_uart_tty_receive;

        hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup;    // ldisc对应的处理函数

        hci_uart_ldisc.owner = THIS_MODULE;

……

if ((err =   tty_register_ldisc(N_HCI, &hci_uart_ldisc)))

……

bcsp_init();        //取决于hciattach中选择的uart[]

……

}

源码在/drivers/char/tty_io.c

int tty_register_ldisc(int disc, struct   tty_ldisc *new_ldisc)

{

unsigned long flags;

int ret = 0;

if (disc < N_TTY || disc >=   NR_LDISCS)

return -EINVAL;

spin_lock_irqsave(&tty_ldisc_lock, flags);

tty_ldiscs[disc] = *new_ldisc;

tty_ldiscs[disc].num = disc;

tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;

tty_ldiscs[disc].refcount = 0;

spin_unlock_irqrestore(&tty_ldisc_lock, flags);

return ret;

}

/* Line disc dispatch table */

static struct tty_ldisc tty_ldiscs[NR_LDISCS];

bcsp_init()--> hci_uart_register_proto(&bcsp);    //注册proto操作函数

{

if (p->id >= HCI_UART_MAX_PROTO)

return -EINVAL;

if (hup[p->id])

return -EEXIST;

hup[p->id] = p;    //static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];

return 0;

}

struct   hci_uart_proto {

unsigned int id;

int (*open)(struct hci_uart *hu);

int (*close)(struct hci_uart *hu);

int (*flush)(struct hci_uart *hu);

int (*recv)(struct hci_uart *hu, void *data, int len);

int (*enqueue)(struct hci_uart *hu, struct sk_buff *skb);

struct sk_buff *(*dequeue)(struct hci_uart *hu);

};

struct   hci_uart {

struct tty_struct *tty;

struct hci_dev *hdev;

unsigned long flags;

unsigned long hdev_flags;

struct hci_uart_proto *proto;

void *priv;

struct sk_buff *tx_skb;

unsigned long tx_state;

spinlock_t rx_lock;

};