sys/dev/audiobell.c

   1 /*      $NetBSD: audiobell.c,v 1.7 2009/05/07 09:23:01 cegger Exp $     */
   2
   3 /*
   4  * Copyright (c) 1999 Richard Earnshaw
   5  * Copyright (c) 2004 Ben Harris
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the RiscBSD team.
  18  * 4. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 #include <sys/types.h>
  34 __KERNEL_RCSID(0, "$NetBSD: audiobell.c,v 1.7 2009/05/07 09:23:01 cegger Exp $");
  35
  36 #include <sys/audioio.h>
  37 #include <sys/conf.h>
  38 #include <sys/device.h>
  39 #include <sys/fcntl.h>
  40 #include <sys/malloc.h>
  41 #include <sys/null.h>
  42 #include <sys/systm.h>
  43 #include <sys/uio.h>
  44
  45 #include <dev/audio_if.h>
  46 #include <dev/audiobellvar.h>
  47
  48 extern dev_type_open(audioopen);
  49 extern dev_type_write(audiowrite);
  50 extern dev_type_close(audioclose);
  51
  52 /* Convert a %age volume to an amount to add to u-law values */
  53 /* XXX Probably highly inaccurate -- should be regenerated */
  54 static const uint8_t volmap[] = {
  55         0x7f, 0x67, 0x5b, 0x53, 0x49, 0x45, 0x41, 0x3e, 0x3a, 0x38,
  56         0x36, 0x32, 0x30, 0x2f, 0x2e, 0x2c, 0x2b, 0x2a, 0x28, 0x27,
  57         0x26, 0x25, 0x23, 0x22, 0x21, 0x1f, 0x1f, 0x1e, 0x1e, 0x1d,
  58         0x1c, 0x1c, 0x1b, 0x1a, 0x1a, 0x19, 0x18, 0x18, 0x17, 0x17,
  59         0x16, 0x15, 0x15, 0x14, 0x13, 0x13, 0x12, 0x11, 0x11, 0x10,
  60         0x0f, 0x0f, 0x0f, 0x0f, 0x0e, 0x0e, 0x0e, 0x0d, 0x0d, 0x0d,
  61         0x0c, 0x0c, 0x0c, 0x0b, 0x0b, 0x0b, 0x0a, 0x0a, 0x0a, 0x09,
  62         0x09, 0x09, 0x08, 0x08, 0x08, 0x07, 0x07, 0x07, 0x07, 0x06,
  63         0x06, 0x06, 0x05, 0x05, 0x05, 0x04, 0x04, 0x04, 0x03, 0x03,
  64         0x03, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00,
  65         0x00
  66 };
  67
  68 /* 1/4 cycle sine wave in u-law */
  69 /* XXX Probably highly inaccurate -- should be regenerated */
  70 static const uint8_t sinewave[] = {
  71         0xff, 0xd3, 0xc5, 0xbc, 0xb6, 0xb0, 0xad, 0xaa,
  72         0xa7, 0xa3, 0xa0, 0x9e, 0x9d, 0x9b, 0x9a, 0x98,
  73         0x97, 0x96, 0x94, 0x93, 0x91, 0x90, 0x8f, 0x8e,
  74         0x8e, 0x8d, 0x8c, 0x8c, 0x8b, 0x8b, 0x8a, 0x89,
  75         0x89, 0x88, 0x88, 0x87, 0x87, 0x86, 0x86, 0x85,
  76         0x85, 0x84, 0x84, 0x84, 0x83, 0x83, 0x83, 0x82,
  77         0x82, 0x82, 0x81, 0x81, 0x81, 0x81, 0x80, 0x80,
  78         0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
  79         0x80,
  80 };
  81
  82 static inline uint8_t
  83 audiobell_ulawscale(uint8_t val, uint8_t vol)
  84 {
  85         uint8_t result;
  86
  87         result = val + vol;
  88         /* Spot underflow and just return silence */
  89         if ((result ^ val) & 0x80)
  90                 return 0x7f;
  91         return result;
  92 }
  93
  94 static inline void
  95 audiobell_expandwave(uint8_t *buf, int volume)
  96 {
  97         u_int i;
  98         int uvol;
  99
 100         KASSERT(volume >= 0 && volume <= 100);
 101         uvol = volmap[volume];
 102         for (i = 0; i < 65; i++)
 103                 buf[i] = audiobell_ulawscale(sinewave[i], uvol);
 104         for (i = 65; i < 128; i++)
 105                  buf[i] = buf[128 - i];
 106         for (i = 128; i < 256; i++)
 107                 buf[i] = buf[i - 128] ^ 0x80;
 108 }
 109
 110 /*
 111  * The algorithm here is based on that described in the RISC OS Programmer's
 112  * Reference Manual (pp1624--1628).
 113  */
 114 static inline int
 115 audiobell_synthesize(uint8_t *buf, u_int pitch, u_int period, u_int volume)
 116 {
 117         uint8_t *wave;
 118         uint16_t phase;
 119
 120         wave = malloc(256, M_TEMP, M_WAITOK);
 121         if (wave == NULL) return -1;
 122         audiobell_expandwave(wave, volume);
 123         pitch = pitch * 65536 / 8000;
 124         period = period * 8; /* 8000 / 1000 */
 125         phase = 0;
 126
 127         for (; period != 0; period--) {
 128                 *buf++ = wave[phase >> 8];
 129                 phase += pitch;
 130         }
 131
 132         free(wave, M_TEMP);
 133         return 0;
 134 }
 135
 136 void
 137 audiobell(void *arg, u_int pitch, u_int period, u_int volume, int poll)
 138 {
 139         device_t audio = arg;
 140         uint8_t *buf;
 141         struct uio auio;
 142         struct iovec aiov;
 143
 144         /* The audio system isn't built for polling. */
 145         if (poll) return;
 146
 147         /* If not configured, we can't beep. */
 148         if (audioopen(AUDIO_DEVICE | device_unit(audio), FWRITE, 0, NULL) != 0)
 149                 return;
 150
 151         buf = malloc(period * 8, M_TEMP, M_WAITOK);
 152         if (buf == NULL) goto out;
 153         if (audiobell_synthesize(buf, pitch, period, volume) != 0) goto out;
 154
 155         aiov.iov_base = (void *)buf;
 156         aiov.iov_len = period * 8;
 157         auio.uio_iov = &aiov;
 158         auio.uio_iovcnt = 1;
 159         auio.uio_offset = 0;
 160         auio.uio_resid = period * 8;
 161         auio.uio_rw = UIO_WRITE;
 162         UIO_SETUP_SYSSPACE(&auio);
 163
 164         audiowrite(AUDIO_DEVICE | device_unit(audio), &auio, 0);
 165
 166 out:
 167         if (buf != NULL) free(buf, M_TEMP);
 168         audioclose(AUDIO_DEVICE | device_unit(audio), FWRITE, 0, NULL);
 169 }