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Annotation of linux/kernel/serial.c, revision 1.1.1.1

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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