keyboard.c

Minix3.11的源码。[MINIX 3是一个为高可靠性应用而设计的自由且简洁的类UNIX系统。]

/* Keyboard driver for PC's and AT's.
 *
 * Changes: 
 *   Jul 13, 2004   processes can observe function keys  (Jorrit N. Herder)
 *   Jun 15, 2004   removed wreboot(), except panic dumps (Jorrit N. Herder)
 *   Feb 04, 1994   loadable keymaps  (Marcus Hampel)
 */

#include "../drivers.h"
#include <sys/time.h>
#include <sys/select.h>
#include <termios.h>
#include <signal.h>
#include <unistd.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/keymap.h>
#include "tty.h"
#include "keymaps/us-std.src"
#include "../../kernel/const.h"
#include "../../kernel/config.h"
#include "../../kernel/type.h"
#include "../../kernel/proc.h"

int irq_hook_id = -1;

/* Standard and AT keyboard.  (PS/2 MCA implies AT throughout.) */
#define KEYBD		0x60	/* I/O port for keyboard data */

/* AT keyboard. */
#define KB_COMMAND	0x64	/* I/O port for commands on AT */
#define KB_STATUS	0x64	/* I/O port for status on AT */
#define KB_ACK		0xFA	/* keyboard ack response */
#define KB_OUT_FULL	0x01	/* status bit set when keypress char pending */
#define KB_IN_FULL	0x02	/* status bit set when not ready to receive */
#define LED_CODE	0xED	/* command to keyboard to set LEDs */
#define MAX_KB_ACK_RETRIES 0x1000	/* max #times to wait for kb ack */
#define MAX_KB_BUSY_RETRIES 0x1000	/* max #times to loop while kb busy */
#define KBIT		0x80	/* bit used to ack characters to keyboard */

/* Miscellaneous. */
#define ESC_SCAN	0x01	/* reboot key when panicking */
#define SLASH_SCAN	0x35	/* to recognize numeric slash */
#define RSHIFT_SCAN	0x36	/* to distinguish left and right shift */
#define HOME_SCAN	0x47	/* first key on the numeric keypad */
#define INS_SCAN	0x52	/* INS for use in CTRL-ALT-INS reboot */
#define DEL_SCAN	0x53	/* DEL for use in CTRL-ALT-DEL reboot */

#define CONSOLE		   0	/* line number for console */
#define KB_IN_BYTES	  32	/* size of keyboard input buffer */
PRIVATE char ibuf[KB_IN_BYTES];	/* input buffer */
PRIVATE char *ihead = ibuf;	/* next free spot in input buffer */
PRIVATE char *itail = ibuf;	/* scan code to return to TTY */
PRIVATE int icount;		/* # codes in buffer */

PRIVATE int esc;		/* escape scan code detected? */
PRIVATE int alt_l;		/* left alt key state */
PRIVATE int alt_r;		/* right alt key state */
PRIVATE int alt;		/* either alt key */
PRIVATE int ctrl_l;		/* left control key state */
PRIVATE int ctrl_r;		/* right control key state */
PRIVATE int ctrl;		/* either control key */
PRIVATE int shift_l;		/* left shift key state */
PRIVATE int shift_r;		/* right shift key state */
PRIVATE int shift;		/* either shift key */
PRIVATE int num_down;		/* num lock key depressed */
PRIVATE int caps_down;		/* caps lock key depressed */
PRIVATE int scroll_down;	/* scroll lock key depressed */
PRIVATE int locks[NR_CONS];	/* per console lock keys state */

/* Lock key active bits.  Chosen to be equal to the keyboard LED bits. */
#define SCROLL_LOCK	0x01
#define NUM_LOCK	0x02
#define CAPS_LOCK	0x04

PRIVATE char numpad_map[] =
		{'H', 'Y', 'A', 'B', 'D', 'C', 'V', 'U', 'G', 'S', 'T', '@'};

/* Variables and definition for observed function keys. */
typedef struct observer { int proc_nr; int events; } obs_t;
PRIVATE obs_t  fkey_obs[12];	/* observers for F1-F12 */
PRIVATE obs_t sfkey_obs[12];	/* observers for SHIFT F1-F12 */

FORWARD _PROTOTYPE( int kb_ack, (void) 					);
FORWARD _PROTOTYPE( int kb_wait, (void)				 	);
FORWARD _PROTOTYPE( int func_key, (int scode) 				);
FORWARD _PROTOTYPE( int scan_keyboard, (void) 				);
FORWARD _PROTOTYPE( unsigned make_break, (int scode) 			);
FORWARD _PROTOTYPE( void set_leds, (void) 				);
FORWARD _PROTOTYPE( void show_key_mappings, (void) 			);
FORWARD _PROTOTYPE( int kb_read, (struct tty *tp, int try) 		);
FORWARD _PROTOTYPE( unsigned map_key, (int scode) 			);

/*===========================================================================*
 *				map_key0				     *
 *===========================================================================*/
/* Map a scan code to an ASCII code ignoring modifiers. */
#define map_key0(scode)	 \
	((unsigned) keymap[(scode) * MAP_COLS])

/*===========================================================================*
 *				map_key					     *
 *===========================================================================*/
PRIVATE unsigned map_key(scode)
int scode;
{
/* Map a scan code to an ASCII code. */

  int caps, column, lk;
  u16_t *keyrow;

  if (scode == SLASH_SCAN && esc) return '/';	/* don't map numeric slash */

  keyrow = &keymap[scode * MAP_COLS];

  caps = shift;
  lk = locks[ccurrent];
  if ((lk & NUM_LOCK) && HOME_SCAN <= scode && scode <= DEL_SCAN) caps = !caps;
  if ((lk & CAPS_LOCK) && (keyrow[0] & HASCAPS)) caps = !caps;

  if (alt) {
	column = 2;
	if (ctrl || alt_r) column = 3;	/* Ctrl + Alt == AltGr */
	if (caps) column = 4;
  } else {
	column = 0;
	if (caps) column = 1;
	if (ctrl) column = 5;
  }
  return keyrow[column] & ~HASCAPS;
}

/*===========================================================================*
 *				kbd_interrupt				     *
 *===========================================================================*/
PUBLIC void kbd_interrupt(m_ptr)
message *m_ptr;
{
/* A keyboard interrupt has occurred.  Process it. */
  int scode;
  static timer_t timer;		/* timer must be static! */

  /* Fetch the character from the keyboard hardware and acknowledge it. */
  scode = scan_keyboard();

  /* Store the scancode in memory so the task can get at it later. */
  if (icount < KB_IN_BYTES) {
	*ihead++ = scode;
	if (ihead == ibuf + KB_IN_BYTES) ihead = ibuf;
	icount++;
	tty_table[ccurrent].tty_events = 1;
	if (tty_table[ccurrent].tty_select_ops & SEL_RD) {
		select_retry(&tty_table[ccurrent]);
	}
  }
}

/*===========================================================================*
 *				kb_read					     *
 *===========================================================================*/
PRIVATE int kb_read(tp, try)
tty_t *tp;
int try;
{
/* Process characters from the circular keyboard buffer. */
  char buf[3];
  int scode;
  unsigned ch;

  tp = &tty_table[ccurrent];		/* always use the current console */

  if (try) {
  	if (icount > 0) return 1;
  	return 0;
  }

  while (icount > 0) {
	scode = *itail++;			/* take one key scan code */
	if (itail == ibuf + KB_IN_BYTES) itail = ibuf;
	icount--;

	/* Function keys are being used for debug dumps. */
	if (func_key(scode)) continue;

	/* Perform make/break processing. */
	ch = make_break(scode);

	if (ch <= 0xFF) {
		/* A normal character. */
		buf[0] = ch;
		(void) in_process(tp, buf, 1);
	} else
	if (HOME <= ch && ch <= INSRT) {
		/* An ASCII escape sequence generated by the numeric pad. */
		buf[0] = ESC;
		buf[1] = '[';
		buf[2] = numpad_map[ch - HOME];
		(void) in_process(tp, buf, 3);
	} else
	if (ch == ALEFT) {
		/* Choose lower numbered console as current console. */
		select_console(ccurrent - 1);
		set_leds();
	} else
	if (ch == ARIGHT) {
		/* Choose higher numbered console as current console. */
		select_console(ccurrent + 1);
		set_leds();
	} else
	if (AF1 <= ch && ch <= AF12) {
		/* Alt-F1 is console, Alt-F2 is ttyc1, etc. */
		select_console(ch - AF1);
		set_leds();
	} else
	if (CF1 <= ch && ch <= CF12) {
	    switch(ch) {
  		case CF1: show_key_mappings(); break; 
  		case CF3: toggle_scroll(); break; /* hardware <-> software */	
  		case CF7: sigchar(&tty_table[CONSOLE], SIGQUIT); break;
  		case CF8: sigchar(&tty_table[CONSOLE], SIGINT); break;
  		case CF9: sigchar(&tty_table[CONSOLE], SIGKILL); break;
  	    }
	}
  }

  return 1;
}

/*===========================================================================*
 *				make_break				     *
 *===========================================================================*/
PRIVATE unsigned make_break(scode)
int scode;			/* scan code of key just struck or released */
{
/* This routine can handle keyboards that interrupt only on key depression,
 * as well as keyboards that interrupt on key depression and key release.
 * For efficiency, the interrupt routine filters out most key releases.
 */
  int ch, make, escape;
  static int CAD_count = 0;

  /* Check for CTRL-ALT-DEL, and if found, halt the computer. This would
   * be better done in keyboard() in case TTY is hung, except control and
   * alt are set in the high level code.
   */
  if (ctrl && alt && (scode == DEL_SCAN || scode == INS_SCAN))
  {
	if (++CAD_count == 3) sys_abort(RBT_HALT);
	sys_kill(INIT_PROC_NR, SIGABRT);
	return -1;
  }

  /* High-order bit set on key release. */
  make = (scode & KEY_RELEASE) == 0;		/* true if pressed */

  ch = map_key(scode &= ASCII_MASK);		/* map to ASCII */

  escape = esc;		/* Key is escaped?  (true if added since the XT) */
  esc = 0;

  switch (ch) {
  	case CTRL:		/* Left or right control key */
		*(escape ? &ctrl_r : &ctrl_l) = make;
		ctrl = ctrl_l | ctrl_r;
		break;
  	case SHIFT:		/* Left or right shift key */
		*(scode == RSHIFT_SCAN ? &shift_r : &shift_l) = make;
		shift = shift_l | shift_r;
		break;
  	case ALT:		/* Left or right alt key */
		*(escape ? &alt_r : &alt_l) = make;
		alt = alt_l | alt_r;
		break;
  	case CALOCK:		/* Caps lock - toggle on 0 -> 1 transition */
		if (caps_down < make) {
			locks[ccurrent] ^= CAPS_LOCK;
			set_leds();
		}
		caps_down = make;
		break;
  	case NLOCK:		/* Num lock */
		if (num_down < make) {
			locks[ccurrent] ^= NUM_LOCK;
			set_leds();
		}
		num_down = make;
		break;
  	case SLOCK:		/* Scroll lock */
		if (scroll_down < make) {
			locks[ccurrent] ^= SCROLL_LOCK;
			set_leds();
		}
		scroll_down = make;
		break;
  	case EXTKEY:		/* Escape keycode */
		esc = 1;		/* Next key is escaped */
		return(-1);
  	default:		/* A normal key */
		if (make) return(ch);
  }

  /* Key release, or a shift type key. */
  return(-1);
}

/*===========================================================================*
 *				set_leds				     *
 *===========================================================================*/
PRIVATE void set_leds()
{
/* Set the LEDs on the caps, num, and scroll lock keys */
  int s;
  if (! machine.pc_at) return;	/* PC/XT doesn't have LEDs */

  kb_wait();			/* wait for buffer empty  */
  if ((s=sys_outb(KEYBD, LED_CODE)) != OK)
      printf("Warning, sys_outb couldn't prepare for LED values: %d\n", s);
   				/* prepare keyboard to accept LED values */
  kb_ack();			/* wait for ack response  */

  kb_wait();			/* wait for buffer empty  */
  if ((s=sys_outb(KEYBD, locks[ccurrent])) != OK)
      printf("Warning, sys_outb couldn't give LED values: %d\n", s);
				/* give keyboard LED values */
  kb_ack();			/* wait for ack response  */
}

/*===========================================================================*
 *				kb_wait					     *
 *===========================================================================*/
PRIVATE int kb_wait()
{
/* Wait until the controller is ready; return zero if this times out. */

  int retries, status, temp;