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Annotation of linux/kernel/serial.c, revision 1.1

1.1     ! root        1: /*
        !             2:  *     serial.c
        !             3:  *
        !             4:  * This module implements the rs232 io functions
        !             5:  *     void rs_write(struct tty_struct * queue);
        !             6:  *     void rs_init(void);
        !             7:  * and all interrupts pertaining to serial IO.
        !             8:  */
        !             9: 
        !            10: #include <linux/tty.h>
        !            11: #include <linux/sched.h>
        !            12: #include <asm/system.h>
        !            13: #include <asm/io.h>
        !            14: 
        !            15: #define WAKEUP_CHARS (TTY_BUF_SIZE/4)
        !            16: 
        !            17: extern void rs1_interrupt(void);
        !            18: extern void rs2_interrupt(void);
        !            19: 
        !            20: static void init(int port)
        !            21: {
        !            22:        outb_p(0x80,port+3);    /* set DLAB of line control reg */
        !            23:        outb_p(0x30,port);      /* LS of divisor (48 -> 2400 bps */
        !            24:        outb_p(0x00,port+1);    /* MS of divisor */
        !            25:        outb_p(0x03,port+3);    /* reset DLAB */
        !            26:        outb_p(0x0b,port+4);    /* set DTR,RTS, OUT_2 */
        !            27:        outb_p(0x0d,port+1);    /* enable all intrs but writes */
        !            28:        (void)inb(port);        /* read data port to reset things (?) */
        !            29: }
        !            30: 
        !            31: void rs_init(void)
        !            32: {
        !            33:        set_intr_gate(0x24,rs1_interrupt);
        !            34:        set_intr_gate(0x23,rs2_interrupt);
        !            35:        init(tty_table[1].read_q.data);
        !            36:        init(tty_table[2].read_q.data);
        !            37:        outb(inb_p(0x21)&0xE7,0x21);
        !            38: }
        !            39: 
        !            40: /*
        !            41:  * This routine gets called when tty_write has put something into
        !            42:  * the write_queue. It must check wheter the queue is empty, and
        !            43:  * set the interrupt register accordingly
        !            44:  *
        !            45:  *     void _rs_write(struct tty_struct * tty);
        !            46:  */
        !            47: void rs_write(struct tty_struct * tty)
        !            48: {
        !            49:        cli();
        !            50:        if (!EMPTY(tty->write_q))
        !            51:                outb(inb_p(tty->write_q.data+1)|0x02,tty->write_q.data+1);
        !            52:        sti();
        !            53: }

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