keyboard.c

LINUX1.0内核源代码,学习LINUX编程的一定要看。

	 * (And SCROLLOCK can also be set by the ioctl KDSETLED.)
	 */
	if (tty->stopped)
		start_tty(tty);
	else
		stop_tty(tty);
}

#if 0
/* unused at present - and the VC_PAUSE bit is not used anywhere either */
static void pause(void)
{
	chg_vc_kbd_mode(kbd,VC_PAUSE);
}
#endif

static void num(void)
{
	if (vc_kbd_mode(kbd,VC_APPLIC)) {
		applkey('P', 1);
		return;
	}
	if (!rep)	/* no autorepeat for numlock, ChN */
		chg_vc_kbd_led(kbd,VC_NUMLOCK);
}

static void lastcons(void)
{
	/* pressing alt-printscreen switches to the last used console, ChN */
	want_console = last_console;
}

static void send_intr(void)
{
	got_break = 1;
}

static void scrll_forw(void)
{
	scrollfront(0);
}

static void scrll_back(void)
{
	scrollback(0);
}

static void boot_it(void)
{
	ctrl_alt_del();
}

static void compose(void)
{
        dead_key_next = 1;
}

static void do_spec(unsigned char value, char up_flag)
{
	typedef void (*fnp)(void);
	fnp fn_table[] = {
		NULL,		enter,		show_ptregs,	show_mem,
		show_state,	send_intr,	lastcons,	caps_toggle,
		num,		hold,		scrll_forw,	scrll_back,
		boot_it,	caps_on,        compose
	};

	if (up_flag)
		return;
	if (value >= SIZE(fn_table))
		return;
	if (!fn_table[value])
		return;
	fn_table[value]();
}

static void do_lowercase(unsigned char value, char up_flag)
{
        printk("keyboard.c: do_lowercase was called - impossible\n");
}
  
static void do_self(unsigned char value, char up_flag)
{
	if (up_flag)
		return;		/* no action, if this is a key release */

        if (diacr)
                value = handle_diacr(value);

        if (dead_key_next) {
                dead_key_next = 0;
                diacr = value;
                return;
        }

	put_queue(value);
}

#define A_GRAVE  '`'
#define A_ACUTE  '\''
#define A_CFLEX  '^'
#define A_TILDE  '~'
#define A_DIAER  '"'
static unsigned char ret_diacr[] =
        {A_GRAVE, A_ACUTE, A_CFLEX, A_TILDE, A_DIAER };

/* If a dead key pressed twice, output a character corresponding to it,	*/
/* otherwise just remember the dead key.				*/

static void do_dead(unsigned char value, char up_flag)
{
	if (up_flag)
		return;

        value = ret_diacr[value];
        if (diacr == value) {   /* pressed twice */
                diacr = 0;
                put_queue(value);
                return;
        }
	diacr = value;
}


/* If space is pressed, return the character corresponding the pending	*/
/* dead key, otherwise try to combine the two.				*/

unsigned char handle_diacr(unsigned char ch)
{
        int d = diacr;
        int i;

        diacr = 0;
        if (ch == ' ')
                return d;

        for (i = 0; i < accent_table_size; i++)
          if(accent_table[i].diacr == d && accent_table[i].base == ch)
            return accent_table[i].result;

        put_queue(d);
        return ch;
}

static void do_cons(unsigned char value, char up_flag)
{
	if (up_flag)
		return;
	want_console = value;
}

static void do_fn(unsigned char value, char up_flag)
{
	if (up_flag)
		return;
	if (value < SIZE(func_table))
	        puts_queue(func_table[value]);
	else
	        printk("do_fn called with value=%d\n", value);
}

static void do_pad(unsigned char value, char up_flag)
{
	static char *pad_chars = "0123456789+-*/\015,.?";
	static char *app_map = "pqrstuvwxylSRQMnn?";

	if (up_flag)
		return;		/* no action, if this is a key release */

	/* kludge... shift forces cursor/number keys */
	if (vc_kbd_mode(kbd,VC_APPLIC) && !k_down[KG_SHIFT]) {
		applkey(app_map[value], 1);
		return;
	}

	if (!vc_kbd_led(kbd,VC_NUMLOCK))
		switch (value) {
			case KVAL(K_PCOMMA):
			case KVAL(K_PDOT):
				do_fn(KVAL(K_REMOVE), 0);
				return;
			case KVAL(K_P0):
				do_fn(KVAL(K_INSERT), 0);
				return;
			case KVAL(K_P1):
				do_fn(KVAL(K_SELECT), 0);
				return;
			case KVAL(K_P2):
				do_cur(KVAL(K_DOWN), 0);
				return;
			case KVAL(K_P3):
				do_fn(KVAL(K_PGDN), 0);
				return;
			case KVAL(K_P4):
				do_cur(KVAL(K_LEFT), 0);
				return;
			case KVAL(K_P6):
				do_cur(KVAL(K_RIGHT), 0);
				return;
			case KVAL(K_P7):
				do_fn(KVAL(K_FIND), 0);
				return;
			case KVAL(K_P8):
				do_cur(KVAL(K_UP), 0);
				return;
			case KVAL(K_P9):
				do_fn(KVAL(K_PGUP), 0);
				return;
			case KVAL(K_P5):
				applkey('G', vc_kbd_mode(kbd, VC_APPLIC));
				return;
		}

	put_queue(pad_chars[value]);
	if (value == KVAL(K_PENTER) && vc_kbd_mode(kbd, VC_CRLF))
		put_queue(10);
}

static void do_cur(unsigned char value, char up_flag)
{
	static char *cur_chars = "BDCA";
	if (up_flag)
		return;

	applkey(cur_chars[value], vc_kbd_mode(kbd,VC_CKMODE));
}

static void do_shift(unsigned char value, char up_flag)
{
	int old_state = shift_state;

	if (rep)
		return;

	/* kludge... */
	if (value == KVAL(K_CAPSSHIFT)) {
		value = KVAL(K_SHIFT);
		clr_vc_kbd_led(kbd, VC_CAPSLOCK);
	}

	if (up_flag) {
	        /* handle the case that two shift or control
		   keys are depressed simultaneously */
		if (k_down[value])
			k_down[value]--;
	} else
		k_down[value]++;

	if (k_down[value])
		shift_state |= (1 << value);
	else
		shift_state &= ~ (1 << value);

	/* kludge */
	if (up_flag && shift_state != old_state && npadch != -1) {
		put_queue(npadch);
		npadch = -1;
	}
}

/* called after returning from RAW mode or when changing consoles -
   recompute k_down[] and shift_state from key_down[] */
void compute_shiftstate(void)
{
        int i, j, k, sym, val;

        shift_state = 0;
	for(i=0; i < SIZE(k_down); i++)
	  k_down[i] = 0;

	for(i=0; i < SIZE(key_down); i++)
	  if(key_down[i]) {	/* skip this word if not a single bit on */
	    k = (i<<5);
	    for(j=0; j<32; j++,k++)
	      if(test_bit(k, key_down)) {
		sym = key_map[0][k];
		if(KTYP(sym) == KT_SHIFT) {
		  val = KVAL(sym);
		  k_down[val]++;
		  shift_state |= (1<<val);
	        }
	      }
	  }
}

static void do_meta(unsigned char value, char up_flag)
{
	if (up_flag)
		return;

	if (vc_kbd_mode(kbd, VC_META)) {
		put_queue('\033');
		put_queue(value);
	} else
		put_queue(value | 0x80);
}

static void do_ascii(unsigned char value, char up_flag)
{
	if (up_flag)
		return;

	if (npadch == -1)
	        npadch = value;
	else
	        npadch = (npadch * 10 + value) % 1000;
}

static void do_lock(unsigned char value, char up_flag)
{
	if (up_flag || rep)
		return;
	chg_vc_kbd_lock(kbd, value);
}

/*
 * send_data sends a character to the keyboard and waits
 * for a acknowledge, possibly retrying if asked to. Returns
 * the success status.
 */
static int send_data(unsigned char data)
{
	int retries = 3;
	int i;

	do {
		kb_wait();
		acknowledge = 0;
		resend = 0;
		outb_p(data, 0x60);
		for(i=0; i<0x20000; i++) {
			inb_p(0x64);		/* just as a delay */
			if (acknowledge)
				return 1;
			if (resend)
				break;
		}
		if (!resend)
			return 0;
	} while (retries-- > 0);
	return 0;
}

/*
 * This routine is the bottom half of the keyboard interrupt
 * routine, and runs with all interrupts enabled. It does
 * console changing, led setting and copy_to_cooked, which can
 * take a reasonably long time.
 *
 * Aside from timing (which isn't really that important for
 * keyboard interrupts as they happen often), using the software
 * interrupt routines for this thing allows us to easily mask
 * this when we don't want any of the above to happen. Not yet
 * used, but this allows for easy and efficient race-condition
 * prevention later on.
 */
static void kbd_bh(void * unused)
{
	static unsigned char old_leds = 0xff;
	unsigned char leds = kbd_table[fg_console].ledstate;

	if (leds != old_leds) {
		old_leds = leds;
		if (!send_data(0xed) || !send_data(leds))
			send_data(0xf4);	/* re-enable kbd if any errors */
	}
	if (want_console >= 0) {
		if (want_console != fg_console) {
			last_console = fg_console;
			change_console(want_console);
		}
		want_console = -1;
	}
	if (got_break) {
		if (tty && !I_IGNBRK(tty)) {
			if (I_BRKINT(tty)) {
				flush_input(tty);
				flush_output(tty);
				if (tty->pgrp > 0)
					kill_pg(tty->pgrp, SIGINT, 1);
			} else {
				cli();
				if (LEFT(&tty->read_q) >= 2) {
					set_bit(tty->read_q.head,
						&tty->readq_flags);
					put_queue(TTY_BREAK);
					put_queue(0);
				}
				sti();
			}
		}
		got_break = 0;
	}
	do_keyboard_interrupt();
	cli();
	if ((inb_p(0x64) & kbd_read_mask) == 0x01)
		fake_keyboard_interrupt();
	sti();
}

long no_idt[2] = {0, 0};

/*
 * This routine reboots the machine by asking the keyboard
 * controller to pulse the reset-line low. We try that for a while,
 * and if it doesn't work, we do some other stupid things.
 */
void hard_reset_now(void)
{
	int i, j;
	extern unsigned long pg0[1024];

	sti();
/* rebooting needs to touch the page at absolute addr 0 */
	pg0[0] = 7;
	*((unsigned short *)0x472) = 0x1234;
	for (;;) {
		for (i=0; i<100; i++) {
			kb_wait();
			for(j = 0; j < 100000 ; j++)
				/* nothing */;
			outb(0xfe,0x64);	 /* pulse reset low */
		}
		__asm__("\tlidt _no_idt");
	}
}

unsigned long kbd_init(unsigned long kmem_start)
{
	int i;
	struct kbd_struct * kbd;

	kbd = kbd_table + 0;
	for (i = 0 ; i < NR_CONSOLES ; i++,kbd++) {
		kbd->ledstate = KBD_DEFLEDS;
		kbd->default_ledstate = KBD_DEFLEDS;
		kbd->lockstate = KBD_DEFLOCK;
		kbd->modeflags = KBD_DEFMODE;
	}

	bh_base[KEYBOARD_BH].routine = kbd_bh;
	request_irq(KEYBOARD_IRQ,keyboard_interrupt);
	mark_bh(KEYBOARD_BH);
	return kmem_start;
}