Add boolean (mute) functionality to softvol plugin

When the resolution is set to 2, a boolean control is created as a
mute switch instead of a volume control.
Also, fixed the possible zero-division error.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/src/pcm/pcm_softvol.c b/src/pcm/pcm_softvol.c
index 7af7f40ba770f3c1833a6da3f175b35e73709691..eee6424ba1308e4da4600cd3f7d040a46c29183b 100644 (file)
--- a/src/pcm/pcm_softvol.c
+++ b/src/pcm/pcm_softvol.c
@@ -275,9 +275,15 @@ static void softvol_convert_stereo_vol(snd_pcm_softvol_t *svol,
                return;
        }
 
-       vol[0] = svol->dB_value[svol->cur_vol[0]];
-       vol[1] = svol->dB_value[svol->cur_vol[1]];
-       vol_c = svol->dB_value[(svol->cur_vol[0] + svol->cur_vol[1]) / 2];
+       if (svol->max_val == 1) {
+               vol[0] = svol->cur_vol[0] ? 0xffff : 0;
+               vol[1] = svol->cur_vol[1] ? 0xffff : 0;
+               vol_c = vol[0] | vol[1];
+       } else {
+               vol[0] = svol->dB_value[svol->cur_vol[0]];
+               vol[1] = svol->dB_value[svol->cur_vol[1]];
+               vol_c = svol->dB_value[(svol->cur_vol[0] + svol->cur_vol[1]) / 2];
+       }
        switch (svol->sformat) {
        case SND_PCM_FORMAT_S16_LE:
        case SND_PCM_FORMAT_S16_BE:
@@ -325,7 +331,10 @@ static void softvol_convert_mono_vol(snd_pcm_softvol_t *svol,
                return;
        }
 
-       vol_scale = svol->dB_value[svol->cur_vol[0]];
+       if (svol->max_val == 1)
+               vol_scale = svol->cur_vol[0] ? 0xffff : 0;
+       else
+               vol_scale = svol->dB_value[svol->cur_vol[0]];
        switch (svol->sformat) {
        case SND_PCM_FORMAT_S16_LE:
        case SND_PCM_FORMAT_S16_BE:
@@ -569,9 +578,13 @@ static void snd_pcm_softvol_dump(snd_pcm_t *pcm, snd_output_t *out)
        snd_pcm_softvol_t *svol = pcm->private_data;
        snd_output_printf(out, "Soft volume PCM\n");
        snd_output_printf(out, "Control: %s\n", svol->elem.id.name);
-       snd_output_printf(out, "min_dB: %g\n", svol->min_dB);
-       snd_output_printf(out, "max_dB: %g\n", svol->max_dB);
-       snd_output_printf(out, "resolution: %d\n", svol->max_val + 1);
+       if (svol->max_val == 1)
+               snd_output_printf(out, "boolean\n");
+       else {
+               snd_output_printf(out, "min_dB: %g\n", svol->min_dB);
+               snd_output_printf(out, "max_dB: %g\n", svol->max_dB);
+               snd_output_printf(out, "resolution: %d\n", svol->max_val + 1);
+       }
        if (pcm->setup) {
                snd_output_printf(out, "Its setup is:\n");
                snd_pcm_dump_setup(pcm, out);
@@ -596,13 +609,21 @@ static int add_user_ctl(snd_pcm_softvol_t *svol, snd_ctl_elem_info_t *cinfo, int
        int i;
        unsigned int def_val;
        
-       err = snd_ctl_elem_add_integer(svol->ctl, &cinfo->id, count, 0, svol->max_val, 0);
+       if (svol->max_val == 1)
+               err = snd_ctl_elem_add_boolean(svol->ctl, &cinfo->id, count);
+       else
+               err = snd_ctl_elem_add_integer(svol->ctl, &cinfo->id, count,
+                                              0, svol->max_val, 0);
        if (err < 0)
                return err;
-       add_tlv_info(svol, cinfo);
-       /* set zero dB value as default, or max_val if
-          there is no 0 dB setting */
-       def_val = svol->zero_dB_val ? svol->zero_dB_val : svol->max_val;
+       if (svol->max_val == 1)
+               def_val = 1;
+       else {
+               add_tlv_info(svol, cinfo);
+               /* set zero dB value as default, or max_val if
+                  there is no 0 dB setting */
+               def_val = svol->zero_dB_val ? svol->zero_dB_val : svol->max_val;
+       }
        for (i = 0; i < count; i++)
                svol->elem.value.integer.value[i] = def_val;
        return snd_ctl_elem_write(svol->ctl, &svol->elem);
@@ -647,7 +668,7 @@ static int softvol_load_control(snd_pcm_t *pcm, snd_pcm_softvol_t *svol,
        svol->max_val = resolution - 1;
        svol->min_dB = min_dB;
        svol->max_dB = max_dB;
-       if (svol->max_dB == ZERO_DB)
+       if (svol->max_val == 1 || svol->max_dB == ZERO_DB)
                svol->zero_dB_val = svol->max_val;
        else if (svol->max_dB < 0)
                svol->zero_dB_val = 0; /* there is no 0 dB setting */
@@ -671,7 +692,8 @@ static int softvol_load_control(snd_pcm_t *pcm, snd_pcm_softvol_t *svol,
                        /* hardware control exists */
                        return 1; /* notify */
 
-               } else if (cinfo->type != SND_CTL_ELEM_TYPE_INTEGER ||
+               } else if ((cinfo->type != SND_CTL_ELEM_TYPE_INTEGER &&
+                           cinfo->type != SND_CTL_ELEM_TYPE_BOOLEAN) ||
                           cinfo->count != (unsigned int)cchannels ||
                           cinfo->value.integer.min != 0 ||
                           cinfo->value.integer.max != resolution - 1) {
@@ -684,7 +706,7 @@ static int softvol_load_control(snd_pcm_t *pcm, snd_pcm_softvol_t *svol,
                                SNDERR("Cannot add a control");
                                return err;
                        }
-               } else {
+               } else if (svol->max_val > 1) {
                        /* check TLV availability */
                        unsigned int tlv[4];
                        err = snd_ctl_elem_tlv_read(svol->ctl, &cinfo->id, tlv, sizeof(tlv));
@@ -693,6 +715,10 @@ static int softvol_load_control(snd_pcm_t *pcm, snd_pcm_softvol_t *svol,
                }
        }
 
+       if (svol->max_val == 1)
+               return 0;
+
+       /* set up dB table */
        if (min_dB == PRESET_MIN_DB && max_dB == ZERO_DB && resolution == PRESET_RESOLUTION)
                svol->dB_value = preset_dB_value;
        else {
@@ -863,6 +889,7 @@ pcm.name {
        [min_dB REAL]           # minimal dB value (default: -51.0)
        [max_dB REAL]           # maximal dB value (default:   0.0)
        [resolution INT]        # resolution (default: 256)
+                               # resolution = 2 means a mute switch
 }
 \endcode
 
@@ -965,7 +992,7 @@ int _snd_pcm_softvol_open(snd_pcm_t **pcmp, const char *name,
                       MAX_DB_UPPER_LIMIT);
                return -EINVAL;
        }
-       if (resolution < 0 || resolution > 1024) {
+       if (resolution <= 1 || resolution > 1024) {
                SNDERR("Invalid resolution value %d", resolution);
                return -EINVAL;
        }