drivers/input/keyboard/fpckbd.c

   1 /*
   2  * fpckbd.c
   3  *
   4  * Copyright 2020, Gary Wong <gtw@gnu.org>
   5  *
   6  * This file is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This file is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this file.  If not, see <https://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/input.h>
  21 #include <linux/io.h>
  22 #include <linux/module.h>
  23 #include <uapi/linux/input-event-codes.h>
  24
  25 MODULE_AUTHOR( "Gary Wong <gtw@gnu.org>" );
  26 MODULE_DESCRIPTION( "FPC-III keyboard driver" );
  27 MODULE_LICENSE( "GPL" );
  28
  29 #define FPCKBD_BASE 0xA0000000
  30
  31 static struct timer_list timer;
  32 static struct input_dev *fpc_dev;
  33 static unsigned char __iomem *report;
  34 static unsigned char last_rep[ 8 ];
  35
  36 static const unsigned char code_trans[ 0x66 ] = {
  37     0, 0, 0, 0, KEY_A, KEY_B, KEY_C, KEY_D,
  38     KEY_E, KEY_F, KEY_G, KEY_H, KEY_I, KEY_J, KEY_K, KEY_L,
  39     KEY_M, KEY_N, KEY_O, KEY_P, KEY_Q, KEY_R, KEY_S, KEY_T,
  40     KEY_U, KEY_V, KEY_W, KEY_X, KEY_Y, KEY_Z, KEY_1, KEY_2,
  41     KEY_3, KEY_4, KEY_5, KEY_6, KEY_7, KEY_8, KEY_9, KEY_0,
  42     KEY_ENTER, KEY_ESC, KEY_BACKSPACE, KEY_TAB,
  43         KEY_SPACE, KEY_MINUS, KEY_EQUAL, KEY_LEFTBRACE,
  44     KEY_RIGHTBRACE, KEY_BACKSLASH, 0, KEY_SEMICOLON,
  45         KEY_APOSTROPHE, KEY_GRAVE, KEY_COMMA, KEY_DOT,
  46     KEY_SLASH, KEY_CAPSLOCK, KEY_F1, KEY_F2,
  47         KEY_F3, KEY_F4, KEY_F5, KEY_F6,
  48     KEY_F7, KEY_F8, KEY_F9, KEY_F10,
  49         KEY_F11, KEY_F12, KEY_SYSRQ, KEY_SCROLLLOCK,
  50     KEY_PAUSE, KEY_INSERT, KEY_HOME, KEY_PAGEUP,
  51     KEY_DELETE, KEY_END, KEY_PAGEDOWN, KEY_RIGHT,
  52     KEY_LEFT, KEY_DOWN, KEY_UP, KEY_NUMLOCK,
  53     KEY_KPSLASH, KEY_KPASTERISK, KEY_KPMINUS, KEY_KPPLUS,
  54     KEY_KPENTER, KEY_KP1, KEY_KP2, KEY_KP3,
  55     KEY_KP4, KEY_KP5, KEY_KP6, KEY_KP7,
  56     KEY_KP8, KEY_KP9, KEY_KP0, KEY_KPDOT,
  57     0, KEY_COMPOSE
  58 };
  59
  60 static const unsigned char mod_trans[ 8 ] = {
  61     KEY_LEFTCTRL, KEY_LEFTSHIFT, KEY_LEFTALT, KEY_LEFTMETA,
  62     KEY_RIGHTCTRL, KEY_RIGHTSHIFT, KEY_RIGHTALT, KEY_RIGHTMETA
  63 };
  64
  65 static void fpckbd_timer( struct timer_list *t ) {
  66
  67     int i, j;
  68     unsigned char new_rep[ 8 ];
  69
  70     memcpy_fromio( new_rep, report, 8 );
  71
  72     for( i = 0; i < 8; i++ )
  73         if( ( new_rep[ 0 ] ^ last_rep[ 0 ] ) & ( 1 << i ) )
  74             input_report_key( fpc_dev, mod_trans[ i ],
  75                               new_rep[ 0 ] & ( 1 << i ) );
  76
  77     for( i = 2; i < 8; i++ )
  78         if( last_rep[ i ] ) {
  79             for( j = 2; j < 8; j++ )
  80                 if( new_rep[ j ] == last_rep[ i ] )
  81                     goto ignore_old;
  82
  83             if( last_rep[ i ] < 0x66 && code_trans[ last_rep[ i ] ] )
  84                 input_report_key( fpc_dev, code_trans[ last_rep[ i ] ], 0 );
  85         ignore_old:
  86             ;
  87         }
  88
  89     for( i = 2; i < 8; i++ )
  90         if( new_rep[ i ] ) {
  91             for( j = 2; j < 8; j++ )
  92                 if( last_rep[ j ] == new_rep[ i ] )
  93                     goto ignore_new;
  94
  95             if( new_rep[ i ] < 0x66 && code_trans[ new_rep[ i ] ] )
  96                 input_report_key( fpc_dev, code_trans[ new_rep[ i ] ], 1 );
  97         ignore_new:
  98             ;
  99         }
 100
 101     input_sync( fpc_dev );
 102
 103     memcpy( last_rep, new_rep, 8 );
 104
 105     mod_timer( &timer, jiffies + HZ / 100 + 1 );
 106 }
 107
 108 static int __init fpckbd_init( void ) {
 109
 110     int i, err;
 111
 112     if( !( fpc_dev = input_allocate_device() ) )
 113         return -ENOMEM;
 114
 115     // FIXME use platform device to get address
 116     if( !( report = ioremap( FPCKBD_BASE, 0x10000 ) ) )
 117         return -ENOMEM;
 118
 119     fpc_dev->evbit[ 0 ] = BIT_MASK( EV_KEY ) | BIT_MASK( EV_REP );
 120
 121     for( i = 1; i < 0x80; i++ )
 122         __set_bit( i, fpc_dev->keybit );
 123
 124     if( ( err = input_register_device( fpc_dev ) ) )
 125         return err;
 126
 127     timer_setup( &timer, fpckbd_timer, 0 );
 128     mod_timer( &timer, jiffies + HZ / 100 + 1 );
 129
 130     return 0;
 131 }
 132
 133 static void __exit fpckbd_exit( void ) {
 134
 135     del_timer_sync( &timer );
 136
 137     input_unregister_device( fpc_dev );
 138
 139     // FIXME iounmap
 140 }
 141
 142 module_init( fpckbd_init );
 143 module_exit( fpckbd_exit );