sound/pci/hda/hda_beep.c

   1 /*
   2  * Digital Beep Input Interface for HD-audio codec
   3  *
   4  * Author: Matthew Ranostay <mranostay@embeddedalley.com>
   5  * Copyright (c) 2008 Embedded Alley Solutions Inc
   6  *
   7  *  This driver is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This driver is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  */
  21
  22 #include <linux/input.h>
  23 #include <linux/pci.h>
  24 #include <linux/workqueue.h>
  25 #include <sound/core.h>
  26 #include "hda_beep.h"
  27 #include "hda_local.h"
  28
  29 enum {
  30         DIGBEEP_HZ_STEP = 46875,        /* 46.875 Hz */
  31         DIGBEEP_HZ_MIN = 93750,         /* 93.750 Hz */
  32         DIGBEEP_HZ_MAX = 12000000,      /* 12 KHz */
  33 };
  34
  35 static void snd_hda_generate_beep(struct work_struct *work)
  36 {
  37         struct hda_beep *beep =
  38                 container_of(work, struct hda_beep, beep_work);
  39         struct hda_codec *codec = beep->codec;
  40
  41         if (!beep->enabled)
  42                 return;
  43
  44         /* generate tone */
  45         snd_hda_codec_write_cache(codec, beep->nid, 0,
  46                         AC_VERB_SET_BEEP_CONTROL, beep->tone);
  47 }
  48
  49 /* (non-standard) Linear beep tone calculation for IDT/STAC codecs
  50  *
  51  * The tone frequency of beep generator on IDT/STAC codecs is
  52  * defined from the 8bit tone parameter, in Hz,
  53  *    freq = 48000 * (257 - tone) / 1024
  54  * that is from 12kHz to 93.75Hz in steps of 46.875 Hz
  55  */
  56 static int beep_linear_tone(struct hda_beep *beep, int hz)
  57 {
  58         if (hz <= 0)
  59                 return 0;
  60         hz *= 1000; /* fixed point */
  61         hz = hz - DIGBEEP_HZ_MIN
  62                 + DIGBEEP_HZ_STEP / 2; /* round to nearest step */
  63         if (hz < 0)
  64                 hz = 0; /* turn off PC beep*/
  65         else if (hz >= (DIGBEEP_HZ_MAX - DIGBEEP_HZ_MIN))
  66                 hz = 1; /* max frequency */
  67         else {
  68                 hz /= DIGBEEP_HZ_STEP;
  69                 hz = 255 - hz;
  70         }
  71         return hz;
  72 }
  73
  74 /* HD-audio standard beep tone parameter calculation
  75  *
  76  * The tone frequency in Hz is calculated as
  77  *   freq = 48000 / (tone * 4)
  78  * from 47Hz to 12kHz
  79  */
  80 static int beep_standard_tone(struct hda_beep *beep, int hz)
  81 {
  82         if (hz <= 0)
  83                 return 0; /* disabled */
  84         hz = 12000 / hz;
  85         if (hz > 0xff)
  86                 return 0xff;
  87         if (hz <= 0)
  88                 return 1;
  89         return hz;
  90 }
  91
  92 static int snd_hda_beep_event(struct input_dev *dev, unsigned int type,
  93                                 unsigned int code, int hz)
  94 {
  95         struct hda_beep *beep = input_get_drvdata(dev);
  96
  97         switch (code) {
  98         case SND_BELL:
  99                 if (hz)
 100                         hz = 1000;
 101         case SND_TONE:
 102                 if (beep->linear_tone)
 103                         beep->tone = beep_linear_tone(beep, hz);
 104                 else
 105                         beep->tone = beep_standard_tone(beep, hz);
 106                 break;
 107         default:
 108                 return -1;
 109         }
 110
 111         /* schedule beep event */
 112         schedule_work(&beep->beep_work);
 113         return 0;
 114 }
 115
 116 int snd_hda_attach_beep_device(struct hda_codec *codec, int nid)
 117 {
 118         struct input_dev *input_dev;
 119         struct hda_beep *beep;
 120         int err;
 121
 122         if (!snd_hda_get_bool_hint(codec, "beep"))
 123                 return 0; /* disabled explicitly */
 124
 125         beep = kzalloc(sizeof(*beep), GFP_KERNEL);
 126         if (beep == NULL)
 127                 return -ENOMEM;
 128         snprintf(beep->phys, sizeof(beep->phys),
 129                 "card%d/codec#%d/beep0", codec->bus->card->number, codec->addr);
 130         input_dev = input_allocate_device();
 131         if (!input_dev) {
 132                 kfree(beep);
 133                 return -ENOMEM;
 134         }
 135
 136         /* setup digital beep device */
 137         input_dev->name = "HDA Digital PCBeep";
 138         input_dev->phys = beep->phys;
 139         input_dev->id.bustype = BUS_PCI;
 140
 141         input_dev->id.vendor = codec->vendor_id >> 16;
 142         input_dev->id.product = codec->vendor_id & 0xffff;
 143         input_dev->id.version = 0x01;
 144
 145         input_dev->evbit[0] = BIT_MASK(EV_SND);
 146         input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);
 147         input_dev->event = snd_hda_beep_event;
 148         input_dev->dev.parent = &codec->bus->pci->dev;
 149         input_set_drvdata(input_dev, beep);
 150
 151         err = input_register_device(input_dev);
 152         if (err < 0) {
 153                 input_free_device(input_dev);
 154                 kfree(beep);
 155                 return err;
 156         }
 157
 158         /* enable linear scale */
 159         snd_hda_codec_write(codec, nid, 0,
 160                 AC_VERB_SET_DIGI_CONVERT_2, 0x01);
 161
 162         beep->nid = nid;
 163         beep->dev = input_dev;
 164         beep->codec = codec;
 165         beep->enabled = 1;
 166         codec->beep = beep;
 167
 168         INIT_WORK(&beep->beep_work, &snd_hda_generate_beep);
 169         return 0;
 170 }
 171 EXPORT_SYMBOL_HDA(snd_hda_attach_beep_device);
 172
 173 void snd_hda_detach_beep_device(struct hda_codec *codec)
 174 {
 175         struct hda_beep *beep = codec->beep;
 176         if (beep) {
 177                 cancel_work_sync(&beep->beep_work);
 178
 179                 input_unregister_device(beep->dev);
 180                 kfree(beep);
 181                 codec->beep = NULL;
 182         }
 183 }
 184 EXPORT_SYMBOL_HDA(snd_hda_detach_beep_device);