FreeBSD/Linux Kernel Cross Reference
sys/i386/isa/kbdio.c

     /*-
      * Copyright (c) 1996 Kazutaka YOKOTA (yokota@zodiac.mech.utsunomiya-u.ac.jp)
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. The name of the author may not be used to endorse or promote 
     *    products derived from this software without specific prior written 
     *    permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     * $FreeBSD: src/sys/i386/isa/kbdio.c,v 1.1.2.7 1999/09/05 08:13:07 peter Exp $
     */
    
    #include "sc.h"
    #include "vt.h"
    #include "psm.h"
    #include "opt_kbdio.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/syslog.h>
    #include <machine/clock.h>
    #ifdef PC98
    #include <pc98/pc98/pc98.h>
    #else
    #include <i386/isa/isa.h>
    #endif
    #include <i386/isa/isa_device.h>
    #include <i386/isa/kbdio.h>
    
    /* 
     * driver specific options: the following options may be set by
     * `options' statements in the kernel configuration file. 
     */
    
    /* retry count */
    #ifndef KBD_MAXRETRY
    #define KBD_MAXRETRY    3
    #endif
    
    /* timing parameters */
    #ifndef KBD_RESETDELAY
    #define KBD_RESETDELAY  200     /* wait 200msec after kbd/mouse reset */
    #endif
    #ifndef KBD_MAXWAIT
    #define KBD_MAXWAIT     5       /* wait 5 times at most after reset */
    #endif
    
    /* I/O recovery time */
    #ifdef PC98
    #define KBDC_DELAYTIME  37
    #define KBDD_DELAYTIME  37
    #else
    #define KBDC_DELAYTIME  20
    #define KBDD_DELAYTIME  7
    #endif
    
    /* debug option */
    #ifndef KBDIO_DEBUG
    #define KBDIO_DEBUG     0
    #endif
    
    /* end of driver specific options */
    
    /* constants */
    
    #define NKBDC           max(max(NSC, NVT), NPSM)
    #define KBDQ_BUFSIZE    32
    
    /* macros */
    
    #ifndef max
    #define max(x,y)        ((x) > (y) ? (x) : (y))
    #endif
    #ifndef min
    #define min(x,y)        ((x) < (y) ? (x) : (y))
    #endif
    
    #define kbdcp(p)        ((struct kbdc_softc *)(p))
    #define nextq(i)        (((i) + 1) % KBDQ_BUFSIZE)
    #define availq(q)       ((q)->head != (q)->tail)
   #if KBDIO_DEBUG >= 2
   #define emptyq(q)       ((q)->tail = (q)->head = (q)->qcount = 0)
   #else
   #define emptyq(q)       ((q)->tail = (q)->head = 0)
   #endif
   
   /* local variables */
   
   typedef struct _kqueue {
       int head;
       int tail;
       unsigned char q[KBDQ_BUFSIZE];
   #if KBDIO_DEBUG >= 2
       int call_count;
       int qcount;
       int max_qcount;
   #endif
   } kqueue;
   
   struct kbdc_softc {
       int port;                   /* base port address */
       int command_byte;           /* current command byte value */
       int command_mask;           /* command byte mask bits for kbd/aux devices */
       int lock;                   /* FIXME: XXX not quite a semaphore... */
       kqueue kbd;                 /* keyboard data queue */
       kqueue aux;                 /* auxiliary data queue */
   }; 
   
   static struct kbdc_softc kbdc_softc[NKBDC] = { { 0 }, };
   
   static int verbose = KBDIO_DEBUG;
   
   /* function prototypes */
   
   #ifndef PC98
   static int addq(kqueue *q, int c);
   static int removeq(kqueue *q);
   static int wait_while_controller_busy(struct kbdc_softc *kbdc);
   static int wait_for_data(struct kbdc_softc *kbdc);
   #endif
   static int wait_for_kbd_data(struct kbdc_softc *kbdc);
   #ifndef PC98
   static int wait_for_kbd_ack(struct kbdc_softc *kbdc);
   static int wait_for_aux_data(struct kbdc_softc *kbdc);
   static int wait_for_aux_ack(struct kbdc_softc *kbdc);
   #endif
   
   /* associate a port number with a KBDC */
   
   KBDC 
   kbdc_open(int port)
   {
   #ifdef PC98
           if (NKBDC) {
                   /* PC-98 has only one keyboard I/F */
                   kbdc_softc[0].port = port;
                   kbdc_softc[0].lock = FALSE;
                   return (KBDC)&kbdc_softc[0];
           }
           return NULL;    /* You didn't include sc driver in your config file */
   #else
       int s;
       int i;
   
       s = spltty();
       for (i = 0; i < NKBDC; ++i) {
           if (kbdc_softc[i].port == port) {
               splx(s);
               return (KBDC) &kbdc_softc[i];
           }
           if (kbdc_softc[i].port <= 0) {
               kbdc_softc[i].port = port;
               kbdc_softc[i].command_byte = -1;
               kbdc_softc[i].command_mask = 0;
               kbdc_softc[i].lock = FALSE;
               kbdc_softc[i].kbd.head = kbdc_softc[i].kbd.tail = 0;
               kbdc_softc[i].aux.head = kbdc_softc[i].aux.tail = 0;
   #if KBDIO_DEBUG >= 2
               kbdc_softc[i].kbd.call_count = 0;
               kbdc_softc[i].kbd.qcount = kbdc_softc[i].kbd.max_qcount = 0;
               kbdc_softc[i].aux.call_count = 0;
               kbdc_softc[i].aux.qcount = kbdc_softc[i].aux.max_qcount = 0;
   #endif
               splx(s);
               return (KBDC) &kbdc_softc[i];
           }
       }
       splx(s);
       return NULL;
   #endif
   }
   
   /*
    * I/O access arbitration in `kbdio'
    *
    * The `kbdio' module uses a simplistic convention to arbitrate
    * I/O access to the controller/keyboard/mouse. The convention requires
    * close cooperation of the calling device driver.
    *
    * The device driver which utilizes the `kbdio' module are assumed to
    * have the following set of routines.
    *    a. An interrupt handler (the bottom half of the driver).
    *    b. Timeout routines which may briefly polls the keyboard controller.
    *    c. Routines outside interrupt context (the top half of the driver).
    * They should follow the rules below:
    *    1. The interrupt handler may assume that it always has full access 
    *       to the controller/keyboard/mouse.
    *    2. The other routines must issue `spltty()' if they wish to 
    *       prevent the interrupt handler from accessing 
    *       the controller/keyboard/mouse.
    *    3. The timeout routines and the top half routines of the device driver
    *       arbitrate I/O access by observing the lock flag in `kbdio'.
    *       The flag is manipulated via `kbdc_lock()'; when one wants to
    *       perform I/O, call `kbdc_lock(kbdc, TRUE)' and proceed only if
    *       the call returns with TRUE. Otherwise the caller must back off.
    *       Call `kbdc_lock(kbdc, FALSE)' when necessary I/O operaion
    *       is finished. This mechanism does not prevent the interrupt 
    *       handler from being invoked at any time and carrying out I/O.
    *       Therefore, `spltty()' must be strategically placed in the device
    *       driver code. Also note that the timeout routine may interrupt
    *       `kbdc_lock()' called by the top half of the driver, but this
    *       interruption is OK so long as the timeout routine observes the
    *       the rule 4 below.
    *    4. The interrupt and timeout routines should not extend I/O operation
    *       across more than one interrupt or timeout; they must complete
    *       necessary I/O operation within one invokation of the routine.
    *       This measns that if the timeout routine acquires the lock flag,
    *       it must reset the flag to FALSE before it returns.
    */
   
   /* set/reset polling lock */
   int 
   kbdc_lock(KBDC p, int lock)
   {
       int prevlock;
   
       prevlock = kbdcp(p)->lock;
       kbdcp(p)->lock = lock;
   
       return (prevlock != lock);
   }
   
   /* check if any data is waiting to be processed */
   int
   kbdc_data_ready(KBDC p)
   {
   #ifdef PC98
           return (inb(kbdcp(p)->port + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL);
   #else
       return (availq(&kbdcp(p)->kbd) || availq(&kbdcp(p)->aux) 
           || (inb(kbdcp(p)->port + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL));
   #endif
   }
   
   #ifndef PC98
   /* queuing functions */
   
   static int
   addq(kqueue *q, int c)
   {
       if (nextq(q->tail) != q->head) {
           q->q[q->tail] = c;
           q->tail = nextq(q->tail);
   #if KBDIO_DEBUG >= 2
           ++q->call_count;
           ++q->qcount;
           if (q->qcount > q->max_qcount)
               q->max_qcount = q->qcount;
   #endif
           return TRUE;
       }
       return FALSE;
   }
   
   static int
   removeq(kqueue *q)
   {
       int c;
   
       if (q->tail != q->head) {
           c = q->q[q->head];
           q->head = nextq(q->head);
   #if KBDIO_DEBUG >= 2
           --q->qcount;
   #endif
           return c;
       }
       return -1;
   }
   
   /* 
    * device I/O routines
    */
   static int
   wait_while_controller_busy(struct kbdc_softc *kbdc)
   {
       /* CPU will stay inside the loop for 100msec at most */
       int retry = 5000;
       int port = kbdc->port;
       int f;
   
       while ((f = inb(port + KBD_STATUS_PORT)) & KBDS_INPUT_BUFFER_FULL) {
           if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               addq(&kbdc->kbd, inb(port + KBD_DATA_PORT));
           } else if ((f & KBDS_BUFFER_FULL) == KBDS_AUX_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               addq(&kbdc->aux, inb(port + KBD_DATA_PORT));
           }
           DELAY(KBDC_DELAYTIME);
           if (--retry < 0)
               return FALSE;
       }
       return TRUE;
   }
   
   /*
    * wait for any data; whether it's from the controller, 
    * the keyboard, or the aux device.
    */
   static int
   wait_for_data(struct kbdc_softc *kbdc)
   {
       /* CPU will stay inside the loop for 200msec at most */
       int retry = 10000;
       int port = kbdc->port;
       int f;
   
       while ((f = inb(port + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL) == 0) {
           DELAY(KBDC_DELAYTIME);
           if (--retry < 0)
               return 0;
       }
       DELAY(KBDD_DELAYTIME);
       return f;
   }
   #endif /* !PC98 */
   
   /* wait for data from the keyboard */
   static int
   wait_for_kbd_data(struct kbdc_softc *kbdc)
   {
       /* CPU will stay inside the loop for 200msec at most */
       int retry = 10000;
       int port = kbdc->port;
       int f;
   
       while ((f = inb(port + KBD_STATUS_PORT) & KBDS_BUFFER_FULL) 
               != KBDS_KBD_BUFFER_FULL) {
   #ifdef PC98
               DELAY(KBDD_DELAYTIME);
   #else
           if (f == KBDS_AUX_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               addq(&kbdc->aux, inb(port + KBD_DATA_PORT));
           }
   #endif
           DELAY(KBDC_DELAYTIME);
           if (--retry < 0)
               return 0;
       }
       DELAY(KBDD_DELAYTIME);
       return f;
   }
   
   #ifndef PC98
   /* 
    * wait for an ACK(FAh), RESEND(FEh), or RESET_FAIL(FCh) from the keyboard.
    * queue anything else.
    */
   static int
   wait_for_kbd_ack(struct kbdc_softc *kbdc)
   {
       /* CPU will stay inside the loop for 200msec at most */
       int retry = 10000;
       int port = kbdc->port;
       int f;
       int b;
   
       while (retry-- > 0) {
           if ((f = inb(port + KBD_STATUS_PORT)) & KBDS_ANY_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               b = inb(port + KBD_DATA_PORT);
               if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL) {
                   if ((b == KBD_ACK) || (b == KBD_RESEND) 
                       || (b == KBD_RESET_FAIL))
                       return b;
                   addq(&kbdc->kbd, b);
               } else if ((f & KBDS_BUFFER_FULL) == KBDS_AUX_BUFFER_FULL) {
                   addq(&kbdc->aux, b);
               }
           }
           DELAY(KBDC_DELAYTIME);
       }
       return -1;
   }
   
   /* wait for data from the aux device */
   static int
   wait_for_aux_data(struct kbdc_softc *kbdc)
   {
       /* CPU will stay inside the loop for 200msec at most */
       int retry = 10000;
       int port = kbdc->port;
       int f;
   
       while ((f = inb(port + KBD_STATUS_PORT) & KBDS_BUFFER_FULL) 
               != KBDS_AUX_BUFFER_FULL) {
           if (f == KBDS_KBD_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               addq(&kbdc->kbd, inb(port + KBD_DATA_PORT));
           }
           DELAY(KBDC_DELAYTIME);
           if (--retry < 0)
               return 0;
       }
       DELAY(KBDD_DELAYTIME);
       return f;
   }
   
   /* 
    * wait for an ACK(FAh), RESEND(FEh), or RESET_FAIL(FCh) from the aux device.
    * queue anything else.
    */
   static int
   wait_for_aux_ack(struct kbdc_softc *kbdc)
   {
       /* CPU will stay inside the loop for 200msec at most */
       int retry = 10000;
       int port = kbdc->port;
       int f;
       int b;
   
       while (retry-- > 0) {
           if ((f = inb(port + KBD_STATUS_PORT)) & KBDS_ANY_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               b = inb(port + KBD_DATA_PORT);
               if ((f & KBDS_BUFFER_FULL) == KBDS_AUX_BUFFER_FULL) {
                   if ((b == PSM_ACK) || (b == PSM_RESEND) 
                       || (b == PSM_RESET_FAIL))
                       return b;
                   addq(&kbdc->aux, b);
               } else if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL) {
                   addq(&kbdc->kbd, b);
               }
           }
           DELAY(KBDC_DELAYTIME);
       }
       return -1;
   }
   
   /* write a one byte command to the controller */
   int
   write_controller_command(KBDC p, int c)
   {
       if (!wait_while_controller_busy(kbdcp(p)))
           return FALSE;
       outb(kbdcp(p)->port + KBD_COMMAND_PORT, c);
       return TRUE;
   }
   
   /* write a one byte data to the controller */
   int
   write_controller_data(KBDC p, int c)
   {
       if (!wait_while_controller_busy(kbdcp(p)))
           return FALSE;
       outb(kbdcp(p)->port + KBD_DATA_PORT, c);
       return TRUE;
   }
   
   /* write a one byte keyboard command */
   int
   write_kbd_command(KBDC p, int c)
   {
       if (!wait_while_controller_busy(kbdcp(p)))
           return FALSE;
       outb(kbdcp(p)->port + KBD_DATA_PORT, c);
       return TRUE;
   }
   
   /* write a one byte auxiliary device command */
   int
   write_aux_command(KBDC p, int c)
   {
       if (!write_controller_command(p, KBDC_WRITE_TO_AUX))
           return FALSE;
       return write_controller_data(p, c);
   }
   
   /* send a command to the keyboard and wait for ACK */
   int
   send_kbd_command(KBDC p, int c)
   {
       int retry = KBD_MAXRETRY;
       int res = -1;
   
       while (retry-- > 0) {
           if (!write_kbd_command(p, c))
               continue;
           res = wait_for_kbd_ack(kbdcp(p));
           if (res == KBD_ACK)
               break;
       }
       return res;
   }
   
   /* send a command to the auxiliary device and wait for ACK */
   int
   send_aux_command(KBDC p, int c)
   {
       int retry = KBD_MAXRETRY;
       int res = -1;
   
       while (retry-- > 0) {
           if (!write_aux_command(p, c))
               continue;
           /*
            * FIXME: XXX
            * The aux device may have already sent one or two bytes of 
            * status data, when a command is received. It will immediately 
            * stop data transmission, thus, leaving an incomplete data 
            * packet in our buffer. We have to discard any unprocessed
            * data in order to remove such packets. Well, we may remove 
            * unprocessed, but necessary data byte as well... 
            */
           emptyq(&kbdcp(p)->aux);
           res = wait_for_aux_ack(kbdcp(p));
           if (res == PSM_ACK)
               break;
       }
       return res;
   }
   
   /* send a command and a data to the keyboard, wait for ACKs */
   int
   send_kbd_command_and_data(KBDC p, int c, int d)
   {
       int retry;
       int res = -1;
   
       for (retry = KBD_MAXRETRY; retry > 0; --retry) {
           if (!write_kbd_command(p, c))
               continue;
           res = wait_for_kbd_ack(kbdcp(p));
           if (res == KBD_ACK)
               break;
           else if (res != KBD_RESEND)
               return res;
       }
       if (retry <= 0)
           return res;
   
       for (retry = KBD_MAXRETRY, res = -1; retry > 0; --retry) {
           if (!write_kbd_command(p, d))
               continue;
           res = wait_for_kbd_ack(kbdcp(p));
           if (res != KBD_RESEND)
               break;
       }
       return res;
   }
   
   /* send a command and a data to the auxiliary device, wait for ACKs */
   int
   send_aux_command_and_data(KBDC p, int c, int d)
   {
       int retry;
       int res = -1;
   
       for (retry = KBD_MAXRETRY; retry > 0; --retry) {
           if (!write_aux_command(p, c))
               continue;
           emptyq(&kbdcp(p)->aux);
           res = wait_for_aux_ack(kbdcp(p));
           if (res == PSM_ACK)
               break;
           else if (res != PSM_RESEND)
               return res;
       }
       if (retry <= 0)
           return res;
   
       for (retry = KBD_MAXRETRY, res = -1; retry > 0; --retry) {
           if (!write_aux_command(p, d))
               continue;
           res = wait_for_aux_ack(kbdcp(p));
           if (res != PSM_RESEND)
               break;
       }
       return res;
   }
   
   /* 
    * read one byte from any source; whether from the controller,
    * the keyboard, or the aux device
    */
   int
   read_controller_data(KBDC p)
   {
       if (availq(&kbdcp(p)->kbd)) 
           return removeq(&kbdcp(p)->kbd);
       if (availq(&kbdcp(p)->aux)) 
           return removeq(&kbdcp(p)->aux);
       if (!wait_for_data(kbdcp(p)))
           return -1;              /* timeout */
       return inb(kbdcp(p)->port + KBD_DATA_PORT);
   }
   #endif /* !PC98 */
   
   #if KBDIO_DEBUG >= 2
   static int call = 0;
   #endif
   
   /* read one byte from the keyboard */
   int
   read_kbd_data(KBDC p)
   {
   #ifndef PC98
   #if KBDIO_DEBUG >= 2
       if (++call > 2000) {
           call = 0;
           log(LOG_DEBUG, "KBDIO: kbd q: %d calls, max %d chars, "
                                 "aux q: %d calls, max %d chars\n",
                          kbdcp(p)->kbd.call_count, kbdcp(p)->kbd.max_qcount,
                          kbdcp(p)->aux.call_count, kbdcp(p)->aux.max_qcount);
       }
   #endif
   
       if (availq(&kbdcp(p)->kbd)) 
           return removeq(&kbdcp(p)->kbd);
   #endif /* !PC98 */
       if (!wait_for_kbd_data(kbdcp(p)))
           return -1;              /* timeout */
   #ifdef PC98
       DELAY(KBDC_DELAYTIME);
   #endif
       return inb(kbdcp(p)->port + KBD_DATA_PORT);
   }
   
   /* read one byte from the keyboard, but return immediately if 
    * no data is waiting
    */
   int
   read_kbd_data_no_wait(KBDC p)
   {
       int f;
   
   #ifdef PC98
       f = inb(kbdcp(p)->port + KBD_STATUS_PORT) & KBDS_BUFFER_FULL;
   #else
   #if KBDIO_DEBUG >= 2
       if (++call > 2000) {
           call = 0;
           log(LOG_DEBUG, "KBDIO: kbd q: %d calls, max %d chars, "
                                 "aux q: %d calls, max %d chars\n",
                          kbdcp(p)->kbd.call_count, kbdcp(p)->kbd.max_qcount,
                          kbdcp(p)->aux.call_count, kbdcp(p)->aux.max_qcount);
       }
   #endif
   
       if (availq(&kbdcp(p)->kbd)) 
           return removeq(&kbdcp(p)->kbd);
       f = inb(kbdcp(p)->port + KBD_STATUS_PORT) & KBDS_BUFFER_FULL;
       if (f == KBDS_AUX_BUFFER_FULL) {
           DELAY(KBDD_DELAYTIME);
           addq(&kbdcp(p)->aux, inb(kbdcp(p)->port + KBD_DATA_PORT));
           f = inb(kbdcp(p)->port + KBD_STATUS_PORT) & KBDS_BUFFER_FULL;
       }
   #endif /* PC98 */
       if (f == KBDS_KBD_BUFFER_FULL) {
           DELAY(KBDD_DELAYTIME);
           return inb(kbdcp(p)->port + KBD_DATA_PORT);
       }
       return -1;          /* no data */
   }
   
   #ifndef PC98
   /* read one byte from the aux device */
   int
   read_aux_data(KBDC p)
   {
       if (availq(&kbdcp(p)->aux)) 
           return removeq(&kbdcp(p)->aux);
       if (!wait_for_aux_data(kbdcp(p)))
           return -1;              /* timeout */
       return inb(kbdcp(p)->port + KBD_DATA_PORT);
   }
   
   /* read one byte from the aux device, but return immediately if 
    * no data is waiting
    */
   int
   read_aux_data_no_wait(KBDC p)
   {
       int f;
   
       if (availq(&kbdcp(p)->aux)) 
           return removeq(&kbdcp(p)->aux);
       f = inb(kbdcp(p)->port + KBD_STATUS_PORT) & KBDS_BUFFER_FULL;
       if (f == KBDS_KBD_BUFFER_FULL) {
           DELAY(KBDD_DELAYTIME);
           addq(&kbdcp(p)->kbd, inb(kbdcp(p)->port + KBD_DATA_PORT));
           f = inb(kbdcp(p)->port + KBD_STATUS_PORT) & KBDS_BUFFER_FULL;
       }
       if (f == KBDS_AUX_BUFFER_FULL) {
           DELAY(KBDD_DELAYTIME);
           return inb(kbdcp(p)->port + KBD_DATA_PORT);
       }
       return -1;          /* no data */
   }
   
   /* discard data from the keyboard */
   void
   empty_kbd_buffer(KBDC p, int wait)
   {
       int t;
       int b;
       int f;
   #if KBDIO_DEBUG >= 2
       int c1 = 0;
       int c2 = 0;
   #endif
       int delta = 2;
   
       for (t = wait; t > 0; ) { 
           if ((f = inb(kbdcp(p)->port + KBD_STATUS_PORT)) & KBDS_ANY_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               b = inb(kbdcp(p)->port + KBD_DATA_PORT);
               if ((f & KBDS_BUFFER_FULL) == KBDS_AUX_BUFFER_FULL) {
                   addq(&kbdcp(p)->aux, b);
   #if KBDIO_DEBUG >= 2
                   ++c2;
               } else {
                   ++c1;
   #endif
               }
               t = wait;
           } else {
               t -= delta;
           }
           DELAY(delta*1000);
       }
   #if KBDIO_DEBUG >= 2
       if ((c1 > 0) || (c2 > 0))
           log(LOG_DEBUG, "kbdio: %d:%d char read (empty_kbd_buffer)\n", c1, c2);
   #endif
   
       emptyq(&kbdcp(p)->kbd);
   }
   
   /* discard data from the aux device */
   void
   empty_aux_buffer(KBDC p, int wait)
   {
       int t;
       int b;
       int f;
   #if KBDIO_DEBUG >= 2
       int c1 = 0;
       int c2 = 0;
   #endif
       int delta = 2;
   
       for (t = wait; t > 0; ) { 
           if ((f = inb(kbdcp(p)->port + KBD_STATUS_PORT)) & KBDS_ANY_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               b = inb(kbdcp(p)->port + KBD_DATA_PORT);
               if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL) {
                   addq(&kbdcp(p)->kbd, b);
   #if KBDIO_DEBUG >= 2
                   ++c1;
               } else {
                   ++c2;
   #endif
               }
               t = wait;
           } else {
               t -= delta;
           }
           DELAY(delta*1000);
       }
   #if KBDIO_DEBUG >= 2
       if ((c1 > 0) || (c2 > 0))
           log(LOG_DEBUG, "kbdio: %d:%d char read (empty_aux_buffer)\n", c1, c2);
   #endif
   
       emptyq(&kbdcp(p)->aux);
   }
   
   /* discard any data from the keyboard or the aux device */
   void
   empty_both_buffers(KBDC p, int wait)
   {
       int t;
       int f;
   #if KBDIO_DEBUG >= 2
       int c1 = 0;
       int c2 = 0;
   #endif
       int delta = 2;
   
       for (t = wait; t > 0; ) { 
           if ((f = inb(kbdcp(p)->port + KBD_STATUS_PORT)) & KBDS_ANY_BUFFER_FULL) {
               DELAY(KBDD_DELAYTIME);
               (void)inb(kbdcp(p)->port + KBD_DATA_PORT);
   #if KBDIO_DEBUG >= 2
               if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL)
                   ++c1;
               else
                   ++c2;
   #endif
               t = wait;
           } else {
               t -= delta;
           }
           DELAY(delta*1000);
       }
   #if KBDIO_DEBUG >= 2
       if ((c1 > 0) || (c2 > 0))
           log(LOG_DEBUG, "kbdio: %d:%d char read (empty_both_buffers)\n", c1, c2);
   #endif
   
       emptyq(&kbdcp(p)->kbd);
       emptyq(&kbdcp(p)->aux);
   }
   
   /* keyboard and mouse device control */
   
   /* NOTE: enable the keyboard port but disable the keyboard 
    * interrupt before calling "reset_kbd()".
    */
   int
   reset_kbd(KBDC p)
   {
       int retry = KBD_MAXRETRY;
       int again = KBD_MAXWAIT;
       int c = KBD_RESEND;         /* keep the compiler happy */
   
       while (retry-- > 0) {
           empty_both_buffers(p, 10);
           if (!write_kbd_command(p, KBDC_RESET_KBD))
               continue;
           emptyq(&kbdcp(p)->kbd);
           c = read_controller_data(p);
           if (verbose || bootverbose)
               log(LOG_DEBUG, "kbdio: RESET_KBD return code:%04x\n", c);
           if (c == KBD_ACK)       /* keyboard has agreed to reset itself... */
               break;
       }
       if (retry < 0)
           return FALSE;
   
       while (again-- > 0) {
           /* wait awhile, well, in fact we must wait quite loooooooooooong */
           DELAY(KBD_RESETDELAY*1000);
           c = read_controller_data(p);    /* RESET_DONE/RESET_FAIL */
           if (c != -1)    /* wait again if the controller is not ready */
               break;
       }
       if (verbose || bootverbose)
           log(LOG_DEBUG, "kbdio: RESET_KBD status:%04x\n", c);
       if (c != KBD_RESET_DONE)
           return FALSE;
       return TRUE;
   }
   
   /* NOTE: enable the aux port but disable the aux interrupt
    * before calling `reset_aux_dev()'.
    */
   int
   reset_aux_dev(KBDC p)
   {
       int retry = KBD_MAXRETRY;
       int again = KBD_MAXWAIT;
       int c = PSM_RESEND;         /* keep the compiler happy */
   
       while (retry-- > 0) {
           empty_both_buffers(p, 10);
           if (!write_aux_command(p, PSMC_RESET_DEV))
               continue;
           emptyq(&kbdcp(p)->aux);
           /* NOTE: Compaq Armada laptops require extra delay here. XXX */
           for (again = KBD_MAXWAIT; again > 0; --again) {
               DELAY(KBD_RESETDELAY*1000);
               c = read_aux_data_no_wait(p);
               if (c != -1)
                   break;
           }
           if (verbose || bootverbose)
               log(LOG_DEBUG, "kbdio: RESET_AUX return code:%04x\n", c);
           if (c == PSM_ACK)       /* aux dev is about to reset... */
               break;
       }
       if (retry < 0)
           return FALSE;
   
       for (again = KBD_MAXWAIT; again > 0; --again) {
           /* wait awhile, well, quite looooooooooooong */
           DELAY(KBD_RESETDELAY*1000);
           c = read_aux_data_no_wait(p);   /* RESET_DONE/RESET_FAIL */
           if (c != -1)    /* wait again if the controller is not ready */
               break;
       }
       if (verbose || bootverbose)
           log(LOG_DEBUG, "kbdio: RESET_AUX status:%04x\n", c);
       if (c != PSM_RESET_DONE)    /* reset status */
           return FALSE;
   
       c = read_aux_data(p);       /* device ID */
       if (verbose || bootverbose)
           log(LOG_DEBUG, "kbdio: RESET_AUX ID:%04x\n", c);
       /* NOTE: we could check the device ID now, but leave it later... */
       return TRUE;
   }
   
   /* controller diagnostics and setup */
   
   int
   test_controller(KBDC p)
   {
       int retry = KBD_MAXRETRY;
       int again = KBD_MAXWAIT;
       int c = KBD_DIAG_FAIL;
   
       while (retry-- > 0) {
           empty_both_buffers(p, 10);
           if (write_controller_command(p, KBDC_DIAGNOSE))
               break;
       }
       if (retry < 0)
           return FALSE;
   
       emptyq(&kbdcp(p)->kbd);
       while (again-- > 0) {
           /* wait awhile */
           DELAY(KBD_RESETDELAY*1000);
           c = read_controller_data(p);    /* DIAG_DONE/DIAG_FAIL */
           if (c != -1)    /* wait again if the controller is not ready */
               break;
       }
       if (verbose || bootverbose)
           log(LOG_DEBUG, "kbdio: DIAGNOSE status:%04x\n", c);
       return (c == KBD_DIAG_DONE);
   }
   
   int
   test_kbd_port(KBDC p)
   {
       int retry = KBD_MAXRETRY;
       int again = KBD_MAXWAIT;
       int c = -1;
   
       while (retry-- > 0) {
           empty_both_buffers(p, 10);
           if (write_controller_command(p, KBDC_TEST_KBD_PORT))
               break;
       }
       if (retry < 0)
           return FALSE;
   
       emptyq(&kbdcp(p)->kbd);
       while (again-- > 0) {
           c = read_controller_data(p);
           if (c != -1)    /* try again if the controller is not ready */
               break;
       }
       if (verbose || bootverbose)
           log(LOG_DEBUG, "kbdio: TEST_KBD_PORT status:%04x\n", c);
       return c;
   }
   
   int
   test_aux_port(KBDC p)
   {
       int retry = KBD_MAXRETRY;
       int again = KBD_MAXWAIT;
       int c = -1;
   
       while (retry-- > 0) {
           empty_both_buffers(p, 10);
           if (write_controller_command(p, KBDC_TEST_AUX_PORT))
               break;
       }
       if (retry < 0)
           return FALSE;
   
       emptyq(&kbdcp(p)->kbd);
       while (again-- > 0) {
           c = read_controller_data(p);
           if (c != -1)    /* try again if the controller is not ready */
               break;
       }
       if (verbose || bootverbose)
           log(LOG_DEBUG, "kbdio: TEST_AUX_PORT status:%04x\n", c);
       return c;
   }
   
   int
   kbdc_get_device_mask(KBDC p)
  {
      return kbdcp(p)->command_mask;
  }
  
  void
  kbdc_set_device_mask(KBDC p, int mask)
  {
      kbdcp(p)->command_mask = 
          mask & (KBD_KBD_CONTROL_BITS | KBD_AUX_CONTROL_BITS);
  }
  
  int
  get_controller_command_byte(KBDC p)
  {
      if (kbdcp(p)->command_byte != -1)
          return kbdcp(p)->command_byte;
      if (!write_controller_command(p, KBDC_GET_COMMAND_BYTE))
          return -1;
      emptyq(&kbdcp(p)->kbd);
      kbdcp(p)->command_byte = read_controller_data(p);
      return kbdcp(p)->command_byte;
  }
  
  int
  set_controller_command_byte(KBDC p, int mask, int command)
  {
      if (get_controller_command_byte(p) == -1)
          return FALSE;
  
      command = (kbdcp(p)->command_byte & ~mask) | (command & mask);
      if (command & KBD_DISABLE_KBD_PORT) {
          if (!write_controller_command(p, KBDC_DISABLE_KBD_PORT))
              return FALSE;
      }
      if (!write_controller_command(p, KBDC_SET_COMMAND_BYTE))
          return FALSE;
      if (!write_controller_data(p, command))
          return FALSE;
      kbdcp(p)->command_byte = command;
  
      if (verbose)
          log(LOG_DEBUG, "kbdio: new command byte:%04x (set_controller...)\n",
              command);
  
      return TRUE;
  }
  #endif /* !PC98 */

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