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
  28 enum {
  29         DIGBEEP_HZ_STEP = 46875,        /* 46.875 Hz */
  30         DIGBEEP_HZ_MIN = 93750,         /* 93.750 Hz */
  31         DIGBEEP_HZ_MAX = 12000000,      /* 12 KHz */
  32 };
  33
  34 static void snd_hda_generate_beep(struct work_struct *work)
  35 {
  36         struct hda_beep *beep =
  37                 container_of(work, struct hda_beep, beep_work);
  38         struct hda_codec *codec = beep->codec;
  39
  40         if (!beep->enabled)
  41                 return;
  42
  43         /* generate tone */
  44         snd_hda_codec_write_cache(codec, beep->nid, 0,
  45                         AC_VERB_SET_BEEP_CONTROL, beep->tone);
  46 }
  47
  48 /* (non-standard) Linear beep tone calculation for IDT/STAC codecs
  49  *
  50  * The tone frequency of beep generator on IDT/STAC codecs is
  51  * defined from the 8bit tone parameter, in Hz,
  52  *    freq = 48000 * (257 - tone) / 1024
  53  * that is from 12kHz to 93.75Hz in steps of 46.875 Hz
  54  */
  55 static int beep_linear_tone(struct hda_beep *beep, int hz)
  56 {
  57         if (hz <= 0)
  58                 return 0;
  59         hz *= 1000; /* fixed point */
  60         hz = hz - DIGBEEP_HZ_MIN
  61                 + DIGBEEP_HZ_STEP / 2; /* round to nearest step */
  62         if (hz < 0)
  63                 hz = 0; /* turn off PC beep*/
  64         else if (hz >= (DIGBEEP_HZ_MAX - DIGBEEP_HZ_MIN))
  65                 hz = 1; /* max frequency */
  66         else {
  67                 hz /= DIGBEEP_HZ_STEP;
  68                 hz = 255 - hz;
  69         }
  70         return hz;
  71 }
  72
  73 /* HD-audio standard beep tone parameter calculation
  74  *
  75  * The tone frequency in Hz is calculated as
  76  *   freq = 48000 / (tone * 4)
  77  * from 47Hz to 12kHz
  78  */
  79 static int beep_standard_tone(struct hda_beep *beep, int hz)
  80 {
  81         if (hz <= 0)
  82                 return 0; /* disabled */
  83         hz = 12000 / hz;
  84         if (hz > 0xff)
  85                 return 0xff;
  86         if (hz <= 0)
  87                 return 1;
  88         return hz;
  89 }
  90
  91 static int snd_hda_beep_event(struct input_dev *dev, unsigned int type,
  92                                 unsigned int code, int hz)
  93 {
  94         struct hda_beep *beep = input_get_drvdata(dev);
  95
  96         switch (code) {
  97         case SND_BELL:
  98                 if (hz)
  99                         hz = 1000;
 100         case SND_TONE:
 101                 if (beep->linear_tone)
 102                         beep->tone = beep_linear_tone(beep, hz);
 103                 else
 104                         beep->tone = beep_standard_tone(beep, hz);
 105                 break;
 106         default:
 107                 return -1;
 108         }
 109
 110         /* schedule beep event */
 111         schedule_work(&beep->beep_work);
 112         return 0;
 113 }
 114
 115 int snd_hda_attach_beep_device(struct hda_codec *codec, int nid)
 116 {
 117         struct input_dev *input_dev;
 118         struct hda_beep *beep;
 119         int err;
 120
 121         beep = kzalloc(sizeof(*beep), GFP_KERNEL);
 122         if (beep == NULL)
 123                 return -ENOMEM;
 124         snprintf(beep->phys, sizeof(beep->phys),
 125                 "card%d/codec#%d/beep0", codec->bus->card->number, codec->addr);
 126         input_dev = input_allocate_device();
 127         if (!input_dev) {
 128                 kfree(beep);
 129                 return -ENOMEM;
 130         }
 131
 132         /* setup digital beep device */
 133         input_dev->name = "HDA Digital PCBeep";
 134         input_dev->phys = beep->phys;
 135         input_dev->id.bustype = BUS_PCI;
 136
 137         input_dev->id.vendor = codec->vendor_id >> 16;
 138         input_dev->id.product = codec->vendor_id & 0xffff;
 139         input_dev->id.version = 0x01;
 140
 141         input_dev->evbit[0] = BIT_MASK(EV_SND);
 142         input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);
 143         input_dev->event = snd_hda_beep_event;
 144         input_dev->dev.parent = &codec->bus->pci->dev;
 145         input_set_drvdata(input_dev, beep);
 146
 147         err = input_register_device(input_dev);
 148         if (err < 0) {
 149                 input_free_device(input_dev);
 150                 kfree(beep);
 151                 return err;
 152         }
 153
 154         /* enable linear scale */
 155         snd_hda_codec_write(codec, nid, 0,
 156                 AC_VERB_SET_DIGI_CONVERT_2, 0x01);
 157
 158         beep->nid = nid;
 159         beep->dev = input_dev;
 160         beep->codec = codec;
 161         beep->enabled = 1;
 162         codec->beep = beep;
 163
 164         INIT_WORK(&beep->beep_work, &snd_hda_generate_beep);
 165         return 0;
 166 }
 167 EXPORT_SYMBOL_HDA(snd_hda_attach_beep_device);
 168
 169 void snd_hda_detach_beep_device(struct hda_codec *codec)
 170 {
 171         struct hda_beep *beep = codec->beep;
 172         if (beep) {
 173                 cancel_work_sync(&beep->beep_work);
 174
 175                 input_unregister_device(beep->dev);
 176                 kfree(beep);
 177                 codec->beep = NULL;
 178         }
 179 }
 180 EXPORT_SYMBOL_HDA(snd_hda_detach_beep_device);