commands/i386/pc/play.c

   1 /* play.c - command to play a tune  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2005,2007,2009  Free Software Foundation, Inc.
   5  *
   6  *  GRUB 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 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /* Lots of this file is borrowed from GNU/Hurd generic-speaker driver.  */
  21
  22 #include <grub/dl.h>
  23 #include <grub/file.h>
  24 #include <grub/disk.h>
  25 #include <grub/term.h>
  26 #include <grub/misc.h>
  27 #include <grub/machine/time.h>
  28 #include <grub/cpu/io.h>
  29 #include <grub/command.h>
  30 #include <grub/i18n.h>
  31
  32 #define BASE_TEMPO (60 * GRUB_TICKS_PER_SECOND)
  33
  34 /* The speaker port.  */
  35 #define SPEAKER                 0x61
  36
  37 /* If 0, follow state of SPEAKER_DATA bit, otherwise enable output
  38    from timer 2.  */
  39 #define SPEAKER_TMR2            0x01
  40
  41 /* If SPEAKER_TMR2 is not set, this provides direct input into the
  42    speaker.  Otherwise, this enables or disables the output from the
  43    timer.  */
  44 #define SPEAKER_DATA            0x02
  45
  46 /* The PIT channel value ports.  You can write to and read from them.
  47    Do not mess with timer 0 or 1.  */
  48 #define PIT_COUNTER_0           0x40
  49 #define PIT_COUNTER_1           0x41
  50 #define PIT_COUNTER_2           0x42
  51
  52 /* The frequency of the PIT clock.  */
  53 #define PIT_FREQUENCY           0x1234dd
  54
  55 /* The PIT control port.  You can only write to it.  Do not mess with
  56    timer 0 or 1.  */
  57 #define PIT_CTRL                0x43
  58 #define PIT_CTRL_SELECT_MASK    0xc0
  59 #define PIT_CTRL_SELECT_0       0x00
  60 #define PIT_CTRL_SELECT_1       0x40
  61 #define PIT_CTRL_SELECT_2       0x80
  62
  63 /* Read and load control.  */
  64 #define PIT_CTRL_READLOAD_MASK  0x30
  65 #define PIT_CTRL_COUNTER_LATCH  0x00    /* Hold timer value until read.  */
  66 #define PIT_CTRL_READLOAD_LSB   0x10    /* Read/load the LSB.  */
  67 #define PIT_CTRL_READLOAD_MSB   0x20    /* Read/load the MSB.  */
  68 #define PIT_CTRL_READLOAD_WORD  0x30    /* Read/load the LSB then the MSB.  */
  69
  70 /* Mode control.  */
  71 #define PIT_CTRL_MODE_MASK      0x0e
  72
  73 /* Interrupt on terminal count.  Setting the mode sets output to low.
  74    When counter is set and terminated, output is set to high.  */
  75 #define PIT_CTRL_INTR_ON_TERM   0x00
  76
  77 /* Programmable one-shot.  When loading counter, output is set to
  78    high.  When counter terminated, output is set to low.  Can be
  79    triggered again from that point on by setting the gate pin to
  80    high.  */
  81 #define PIT_CTRL_PROGR_ONE_SHOT 0x02
  82
  83 /* Rate generator.  Output is low for one period of the counter, and
  84    high for the other.  */
  85 #define PIT_CTRL_RATE_GEN       0x04
  86
  87 /* Square wave generator.  Output is low for one half of the period,
  88    and high for the other half.  */
  89 #define PIT_CTRL_SQUAREWAVE_GEN 0x06
  90
  91 /* Software triggered strobe.  Setting the mode sets output to high.
  92    When counter is set and terminated, output is set to low.  */
  93 #define PIT_CTRL_SOFTSTROBE     0x08
  94
  95 /* Hardware triggered strobe.  Like software triggered strobe, but
  96    only starts the counter when the gate pin is set to high.  */
  97 #define PIT_CTRL_HARDSTROBE     0x0a
  98
  99 /* Count mode.  */
 100 #define PIT_CTRL_COUNT_MASK     0x01
 101 #define PIT_CTRL_COUNT_BINARY   0x00    /* 16-bit binary counter.  */
 102 #define PIT_CTRL_COUNT_BCD      0x01    /* 4-decade BCD counter.  */
 103
 104 #define T_REST                  ((grub_uint16_t) 0)
 105 #define T_FINE                  ((grub_uint16_t) -1)
 106
 107 struct note
 108 {
 109   grub_uint16_t pitch;
 110   grub_uint16_t duration;
 111 };
 112
 113 static void
 114 beep_off (void)
 115 {
 116   unsigned char status;
 117
 118   status = grub_inb (SPEAKER);
 119   grub_outb (status & ~(SPEAKER_TMR2 | SPEAKER_DATA), SPEAKER);
 120 }
 121
 122 static void
 123 beep_on (grub_uint16_t pitch)
 124 {
 125   unsigned char status;
 126   unsigned int counter;
 127
 128   if (pitch < 20)
 129     pitch = 20;
 130   else if (pitch > 20000)
 131     pitch = 20000;
 132
 133   counter = PIT_FREQUENCY / pitch;
 134
 135   /* Program timer 2.  */
 136   grub_outb (PIT_CTRL_SELECT_2 | PIT_CTRL_READLOAD_WORD
 137         | PIT_CTRL_SQUAREWAVE_GEN | PIT_CTRL_COUNT_BINARY, PIT_CTRL);
 138   grub_outb (counter & 0xff, PIT_COUNTER_2);            /* LSB */
 139   grub_outb ((counter >> 8) & 0xff, PIT_COUNTER_2);     /* MSB */
 140
 141   /* Start speaker.  */
 142   status = grub_inb (SPEAKER);
 143   grub_outb (status | SPEAKER_TMR2 | SPEAKER_DATA, SPEAKER);
 144 }
 145
 146 /* Returns whether playing should continue.  */
 147 static int
 148 play (unsigned tempo, struct note *note)
 149 {
 150   unsigned int to;
 151
 152   if (note->pitch == T_FINE || grub_checkkey () >= 0)
 153     return 1;
 154
 155   grub_dprintf ("play", "pitch = %d, duration = %d\n", note->pitch,
 156                 note->duration);
 157
 158   switch (note->pitch)
 159     {
 160       case T_REST:
 161         beep_off ();
 162         break;
 163
 164       default:
 165         beep_on (note->pitch);
 166         break;
 167     }
 168
 169   to = grub_get_rtc () + BASE_TEMPO * note->duration / tempo;
 170   while (((unsigned int) grub_get_rtc () <= to) && (grub_checkkey () < 0))
 171     ;
 172
 173   return 0;
 174 }
 175
 176 static grub_err_t
 177 grub_cmd_play (grub_command_t cmd __attribute__ ((unused)),
 178                int argc, char **args)
 179 {
 180   grub_file_t file;
 181
 182   if (argc < 1)
 183     return grub_error (GRUB_ERR_BAD_ARGUMENT, "file name or tempo and notes required");
 184
 185   file = grub_file_open (args[0]);
 186   if (file)
 187     {
 188       struct note buf;
 189       grub_uint32_t tempo;
 190
 191       if (grub_file_read (file, &tempo, sizeof (tempo)) != sizeof (tempo))
 192         {
 193           grub_file_close (file);
 194           return grub_error (GRUB_ERR_FILE_READ_ERROR,
 195                              "file doesn't even contains a full tempo record");
 196         }
 197
 198       tempo = grub_le_to_cpu32 (tempo);
 199       grub_dprintf ("play","tempo = %d\n", tempo);
 200
 201       while (grub_file_read (file, &buf,
 202                              sizeof (struct note)) == sizeof (struct note))
 203         {
 204           buf.pitch = grub_le_to_cpu16 (buf.pitch);
 205           buf.duration = grub_le_to_cpu16 (buf.duration);
 206
 207           if (play (tempo, &buf))
 208             break;
 209         }
 210
 211       grub_file_close (file);
 212     }
 213   else
 214     {
 215       char *end;
 216       unsigned tempo;
 217       struct note note;
 218       int i;
 219
 220       tempo = grub_strtoul (args[0], &end, 0);
 221
 222       if (*end)
 223         /* Was not a number either, assume it was supposed to be a file name.  */
 224         return grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
 225
 226       grub_dprintf ("play","tempo = %d\n", tempo);
 227
 228       for (i = 1; i + 1 < argc; i += 2)
 229         {
 230           note.pitch = grub_strtoul (args[i], &end, 0);
 231           if (*end)
 232             {
 233               grub_error (GRUB_ERR_BAD_NUMBER, "bogus pitch number");
 234               break;
 235             }
 236
 237           note.duration = grub_strtoul (args[i + 1], &end, 0);
 238           if (*end)
 239             {
 240               grub_error (GRUB_ERR_BAD_NUMBER, "bogus duration number");
 241               break;
 242             }
 243
 244           if (play (tempo, &note))
 245             break;
 246         }
 247     }
 248
 249   beep_off ();
 250
 251   while (grub_checkkey () > 0)
 252     grub_getkey ();
 253
 254   return 0;
 255 }
 256
 257 static grub_command_t cmd;
 258 \f
 259 GRUB_MOD_INIT(play)
 260 {
 261   cmd = grub_register_command ("play", grub_cmd_play,
 262                                N_("FILE | TEMPO [PITCH1 DURATION1] [PITCH2 DURATION2] ... "),
 263                                N_("Play a tune."));
 264 }
 265
 266 GRUB_MOD_FINI(play)
 267 {
 268   grub_unregister_command (cmd);
 269 }