hda_beep.c

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/*
 * Digital Beep Input Interface for HD-audio codec
 *
 * Author: Matthew Ranostay <[email protected]>
 * Copyright (c) 2008 Embedded Alley Solutions Inc
 *
 *  This driver is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This driver is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/input.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/export.h>
#include <sound/core.h>
#include "hda_beep.h"
#include "hda_local.h"

enum {
    DIGBEEP_HZ_STEP = 46875,    /* 46.875 Hz */
    DIGBEEP_HZ_MIN = 93750,     /* 93.750 Hz */
    DIGBEEP_HZ_MAX = 12000000,  /* 12 KHz */
};

static void snd_hda_generate_beep(struct work_struct *work)
{
    struct hda_beep *beep =
        container_of(work, struct hda_beep, beep_work);
    struct hda_codec *codec = beep->codec;

    if (!beep->enabled)
        return;

    /* generate tone */
    snd_hda_codec_write(codec, beep->nid, 0,
            AC_VERB_SET_BEEP_CONTROL, beep->tone);
}

/* (non-standard) Linear beep tone calculation for IDT/STAC codecs 
 *
 * The tone frequency of beep generator on IDT/STAC codecs is
 * defined from the 8bit tone parameter, in Hz,
 *    freq = 48000 * (257 - tone) / 1024
 * that is from 12kHz to 93.75Hz in steps of 46.875 Hz
 */
static int beep_linear_tone(struct hda_beep *beep, int hz)
{
    if (hz <= 0)
        return 0;
    hz *= 1000; /* fixed point */
    hz = hz - DIGBEEP_HZ_MIN
        + DIGBEEP_HZ_STEP / 2; /* round to nearest step */
    if (hz < 0)
        hz = 0; /* turn off PC beep*/
    else if (hz >= (DIGBEEP_HZ_MAX - DIGBEEP_HZ_MIN))
        hz = 1; /* max frequency */
    else {
        hz /= DIGBEEP_HZ_STEP;
        hz = 255 - hz;
    }
    return hz;
}

/* HD-audio standard beep tone parameter calculation
 *
 * The tone frequency in Hz is calculated as
 *   freq = 48000 / (tone * 4)
 * from 47Hz to 12kHz
 */
static int beep_standard_tone(struct hda_beep *beep, int hz)
{
    if (hz <= 0)
        return 0; /* disabled */
    hz = 12000 / hz;
    if (hz > 0xff)
        return 0xff;
    if (hz <= 0)
        return 1;
    return hz;
}

static int snd_hda_beep_event(struct input_dev *dev, unsigned int type,
                unsigned int code, int hz)
{
    struct hda_beep *beep = input_get_drvdata(dev);

    switch (code) {
    case SND_BELL:
        if (hz)
            hz = 1000;
    case SND_TONE:
        if (beep->linear_tone)
            beep->tone = beep_linear_tone(beep, hz);
        else
            beep->tone = beep_standard_tone(beep, hz);
        break;
    default:
        return -1;
    }

    /* schedule beep event */
    schedule_work(&beep->beep_work);
    return 0;
}

static void snd_hda_do_detach(struct hda_beep *beep)
{
    input_unregister_device(beep->dev);
    beep->dev = NULL;
    cancel_work_sync(&beep->beep_work);
    /* turn off beep for sure */
    snd_hda_codec_write(beep->codec, beep->nid, 0,
                  AC_VERB_SET_BEEP_CONTROL, 0);
}

static int snd_hda_do_attach(struct hda_beep *beep)
{
    struct input_dev *input_dev;
    struct hda_codec *codec = beep->codec;
    int err;

    input_dev = input_allocate_device();
    if (!input_dev) {
        printk(KERN_INFO "hda_beep: unable to allocate input device\n");
        return -ENOMEM;
    }

    /* setup digital beep device */
    input_dev->name = "HDA Digital PCBeep";
    input_dev->phys = beep->phys;
    input_dev->id.bustype = BUS_PCI;

    input_dev->id.vendor = codec->vendor_id >> 16;
    input_dev->id.product = codec->vendor_id & 0xffff;
    input_dev->id.version = 0x01;

    input_dev->evbit[0] = BIT_MASK(EV_SND);
    input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);
    input_dev->event = snd_hda_beep_event;
    input_dev->dev.parent = &codec->bus->pci->dev;
    input_set_drvdata(input_dev, beep);

    err = input_register_device(input_dev);
    if (err < 0) {
        input_free_device(input_dev);
        printk(KERN_INFO "hda_beep: unable to register input device\n");
        return err;
    }
    beep->dev = input_dev;
    return 0;
}

int snd_hda_enable_beep_device(struct hda_codec *codec, int enable)
{
    struct hda_beep *beep = codec->beep;
    if (!beep)
        return 0;
    enable = !!enable;
    if (beep->enabled != enable) {
        beep->enabled = enable;
        if (!enable) {
            cancel_work_sync(&beep->beep_work);
            /* turn off beep */
            snd_hda_codec_write(beep->codec, beep->nid, 0,
                          AC_VERB_SET_BEEP_CONTROL, 0);
        }
        return 1;
    }
    return 0;
}
EXPORT_SYMBOL_HDA(snd_hda_enable_beep_device);

int snd_hda_attach_beep_device(struct hda_codec *codec, int nid)
{
    struct hda_beep *beep;
    int err;

    if (!snd_hda_get_bool_hint(codec, "beep"))
        return 0; /* disabled explicitly by hints */
    if (codec->beep_mode == HDA_BEEP_MODE_OFF)
        return 0; /* disabled by module option */

    beep = kzalloc(sizeof(*beep), GFP_KERNEL);
    if (beep == NULL)
        return -ENOMEM;
    snprintf(beep->phys, sizeof(beep->phys),
        "card%d/codec#%d/beep0", codec->bus->card->number, codec->addr);
    /* enable linear scale */
    snd_hda_codec_write(codec, nid, 0,
        AC_VERB_SET_DIGI_CONVERT_2, 0x01);

    beep->nid = nid;
    beep->codec = codec;
    codec->beep = beep;

    INIT_WORK(&beep->beep_work, &snd_hda_generate_beep);
    mutex_init(&beep->mutex);

    err = snd_hda_do_attach(beep);
    if (err < 0) {
        kfree(beep);
        codec->beep = NULL;
        return err;
    }

    return 0;
}
EXPORT_SYMBOL_HDA(snd_hda_attach_beep_device);

void snd_hda_detach_beep_device(struct hda_codec *codec)
{
    struct hda_beep *beep = codec->beep;
    if (beep) {
        if (beep->dev)
            snd_hda_do_detach(beep);
        codec->beep = NULL;
        kfree(beep);
    }
}
EXPORT_SYMBOL_HDA(snd_hda_detach_beep_device);

static bool ctl_has_mute(struct snd_kcontrol *kcontrol)
{
    struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
    return query_amp_caps(codec, get_amp_nid(kcontrol),
                  get_amp_direction(kcontrol)) & AC_AMPCAP_MUTE;
}

/* get/put callbacks for beep mute mixer switches */
int snd_hda_mixer_amp_switch_get_beep(struct snd_kcontrol *kcontrol,
                      struct snd_ctl_elem_value *ucontrol)
{
    struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
    struct hda_beep *beep = codec->beep;
    if (beep && (!beep->enabled || !ctl_has_mute(kcontrol))) {
        ucontrol->value.integer.value[0] =
            ucontrol->value.integer.value[1] = beep->enabled;
        return 0;
    }
    return snd_hda_mixer_amp_switch_get(kcontrol, ucontrol);
}
EXPORT_SYMBOL_HDA(snd_hda_mixer_amp_switch_get_beep);

int snd_hda_mixer_amp_switch_put_beep(struct snd_kcontrol *kcontrol,
                      struct snd_ctl_elem_value *ucontrol)
{
    struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
    struct hda_beep *beep = codec->beep;
    if (beep) {
        u8 chs = get_amp_channels(kcontrol);
        int enable = 0;
        long *valp = ucontrol->value.integer.value;
        if (chs & 1) {
            enable |= *valp;
            valp++;
        }
        if (chs & 2)
            enable |= *valp;
        snd_hda_enable_beep_device(codec, enable);
    }
    if (!ctl_has_mute(kcontrol))
        return 0;
    return snd_hda_mixer_amp_switch_put(kcontrol, ucontrol);
}
EXPORT_SYMBOL_HDA(snd_hda_mixer_amp_switch_put_beep);