Initial contribution

1 files changed, 332 insertions, 0 deletions

diff --git a/mixer.c b/mixer.c
new file mode 100644
index 0000000..9c7e3b5
--- /dev/null
+++ b/mixer.c
@@ -0,0 +1,332 @@
+/* mixer.c
+**
+** Copyright 2011, The Android Open Source Project
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are met:
+**     * Redistributions of source code must retain the above copyright
+**       notice, this list of conditions and the following disclaimer.
+**     * Redistributions in binary form must reproduce the above copyright
+**       notice, this list of conditions and the following disclaimer in the
+**       documentation and/or other materials provided with the distribution.
+**     * Neither the name of The Android Open Source Project nor the names of
+**       its contributors may be used to endorse or promote products derived
+**       from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY The Android Open Source Project ``AS IS'' AND
+** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+** ARE DISCLAIMED. IN NO EVENT SHALL The Android Open Source Project BE LIABLE
+** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+** DAMAGE.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include <linux/ioctl.h>
+#define __force
+#define __bitwise
+#define __user
+#include <sound/asound.h>
+
+#include <tinyalsa/asoundlib.h>
+
+static const char *elem_iface_name(snd_ctl_elem_iface_t n)
+{
+    switch (n) {
+    case SNDRV_CTL_ELEM_IFACE_CARD: return "CARD";
+    case SNDRV_CTL_ELEM_IFACE_HWDEP: return "HWDEP";
+    case SNDRV_CTL_ELEM_IFACE_MIXER: return "MIXER";
+    case SNDRV_CTL_ELEM_IFACE_PCM: return "PCM";
+    case SNDRV_CTL_ELEM_IFACE_RAWMIDI: return "MIDI";
+    case SNDRV_CTL_ELEM_IFACE_TIMER: return "TIMER";
+    case SNDRV_CTL_ELEM_IFACE_SEQUENCER: return "SEQ";
+    default: return "???";
+    }
+}
+
+static const char *elem_type_name(snd_ctl_elem_type_t n)
+{
+    switch (n) {
+    case SNDRV_CTL_ELEM_TYPE_NONE: return "NONE";
+    case SNDRV_CTL_ELEM_TYPE_BOOLEAN: return "BOOL";
+    case SNDRV_CTL_ELEM_TYPE_INTEGER: return "INT32";
+    case SNDRV_CTL_ELEM_TYPE_ENUMERATED: return "ENUM";
+    case SNDRV_CTL_ELEM_TYPE_BYTES: return "BYTES";
+    case SNDRV_CTL_ELEM_TYPE_IEC958: return "IEC958";
+    case SNDRV_CTL_ELEM_TYPE_INTEGER64: return "INT64";
+    default: return "???";
+    }
+}
+
+
+struct mixer_ctl {
+    struct mixer *mixer;
+    struct snd_ctl_elem_info *info;
+    char **ename;
+};
+
+struct mixer {
+    int fd;
+    struct snd_ctl_elem_info *info;
+    struct mixer_ctl *ctl;
+    unsigned int count;
+};
+
+void mixer_close(struct mixer *mixer)
+{
+    unsigned int n,m;
+
+    if (mixer->fd >= 0)
+        close(mixer->fd);
+
+    if (mixer->ctl) {
+        for (n = 0; n < mixer->count; n++) {
+            if (mixer->ctl[n].ename) {
+                unsigned int max = mixer->ctl[n].info->value.enumerated.items;
+                for (m = 0; m < max; m++)
+                    free(mixer->ctl[n].ename[m]);
+                free(mixer->ctl[n].ename);
+            }
+        }
+        free(mixer->ctl);
+    }
+
+    if (mixer->info)
+        free(mixer->info);
+
+    free(mixer);
+
+    /* TODO: verify frees */
+}
+
+struct mixer *mixer_open(unsigned int device)
+{
+    struct snd_ctl_elem_list elist;
+    struct snd_ctl_elem_info tmp;
+    struct snd_ctl_elem_id *eid = NULL;
+    struct mixer *mixer = NULL;
+    unsigned int n, m;
+    int fd;
+
+    fd = open("/dev/snd/controlC0", O_RDWR);
+    if (fd < 0)
+        return 0;
+
+    memset(&elist, 0, sizeof(elist));
+    if (ioctl(fd, SNDRV_CTL_IOCTL_ELEM_LIST, &elist) < 0)
+        goto fail;
+
+    mixer = calloc(1, sizeof(*mixer));
+    if (!mixer)
+        goto fail;
+
+    mixer->ctl = calloc(elist.count, sizeof(struct mixer_ctl));
+    mixer->info = calloc(elist.count, sizeof(struct snd_ctl_elem_info));
+    if (!mixer->ctl || !mixer->info)
+        goto fail;
+
+    eid = calloc(elist.count, sizeof(struct snd_ctl_elem_id));
+    if (!eid)
+        goto fail;
+
+    mixer->count = elist.count;
+    mixer->fd = fd;
+    elist.space = mixer->count;
+    elist.pids = eid;
+    if (ioctl(fd, SNDRV_CTL_IOCTL_ELEM_LIST, &elist) < 0)
+        goto fail;
+
+    for (n = 0; n < mixer->count; n++) {
+        struct snd_ctl_elem_info *ei = mixer->info + n;
+        ei->id.numid = eid[n].numid;
+        if (ioctl(fd, SNDRV_CTL_IOCTL_ELEM_INFO, ei) < 0)
+            goto fail;
+        mixer->ctl[n].info = ei;
+        mixer->ctl[n].mixer = mixer;
+        if (ei->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
+            char **enames = calloc(ei->value.enumerated.items, sizeof(char*));
+            if (!enames)
+                goto fail;
+            mixer->ctl[n].ename = enames;
+            for (m = 0; m < ei->value.enumerated.items; m++) {
+                memset(&tmp, 0, sizeof(tmp));
+                tmp.id.numid = ei->id.numid;
+                tmp.value.enumerated.item = m;
+                if (ioctl(fd, SNDRV_CTL_IOCTL_ELEM_INFO, &tmp) < 0)
+                    goto fail;
+                enames[m] = strdup(tmp.value.enumerated.name);
+                if (!enames[m])
+                    goto fail;
+            }
+        }
+    }
+
+    free(eid);
+    return mixer;
+
+fail:
+    /* TODO: verify frees in failure case */
+    if (eid)
+        free(eid);
+    if (mixer)
+        mixer_close(mixer);
+    else if (fd >= 0)
+        close(fd);
+    return 0;
+}
+
+int mixer_get_num_ctls(struct mixer *mixer)
+{
+    return mixer->count;
+}
+
+struct mixer_ctl *mixer_get_ctl(struct mixer *mixer, unsigned int id)
+{
+    if (id < mixer->count)
+        return mixer->ctl + id;
+
+    return NULL;
+}
+
+struct mixer_ctl *mixer_get_ctl_by_name(struct mixer *mixer, const char *name)
+{
+    unsigned int n;
+    for (n = 0; n < mixer->count; n++)
+        if (!strcmp(name, (char*) mixer->info[n].id.name))
+            return mixer->ctl + n;
+
+    return NULL;
+}
+
+static int percent_to_int(struct snd_ctl_elem_info *ei, int percent)
+{
+    int range;
+    
+    if (percent > 100)
+        percent = 100;
+    else if (percent < 0)
+        percent = 0;
+    
+    range = (ei->value.integer.max - ei->value.integer.min);
+    
+    return ei->value.integer.min + (range * percent) / 100;
+}
+
+static int int_to_percent(struct snd_ctl_elem_info *ei, int value)
+{
+    int range = (ei->value.integer.max - ei->value.integer.min);
+    
+    if (range == 0)
+        return 0;
+    
+    return ((value - ei->value.integer.min) / range) * 100;
+}
+
+int mixer_ctl_get_percent(struct mixer_ctl *ctl)
+{
+    struct snd_ctl_elem_value ev;
+
+    memset(&ev, 0, sizeof(ev));
+    ev.id.numid = ctl->info->id.numid;
+    if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev))
+        return -1;
+
+    switch (ctl->info->type) {
+    case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+        return !!ev.value.integer.value[0]; /* TODO: handle multiple return values */
+        break;
+    case SNDRV_CTL_ELEM_TYPE_INTEGER: {
+        return int_to_percent(ctl->info, ev.value.integer.value[0]);
+        break;
+    }
+    default:
+        errno = EINVAL;
+        return -1;
+    }
+
+    return 0;
+}
+
+int mixer_ctl_set_percent(struct mixer_ctl *ctl, int percent)
+{
+    struct snd_ctl_elem_value ev;
+    unsigned int n;
+
+    memset(&ev, 0, sizeof(ev));
+    ev.id.numid = ctl->info->id.numid;
+    switch (ctl->info->type) {
+    case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+        for (n = 0; n < ctl->info->count; n++)
+            ev.value.integer.value[n] = !!percent; /* TODO: handle multiple set values */
+        break;
+
+    case SNDRV_CTL_ELEM_TYPE_INTEGER: {
+        int value = percent_to_int(ctl->info, percent);
+        for (n = 0; n < ctl->info->count; n++)
+            ev.value.integer.value[n] = value;
+        break;
+    }
+
+    default:
+        errno = EINVAL;
+        return -1;
+    }
+    
+    return ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_WRITE, &ev);
+}
+
+int mixer_ctl_set_enum(struct mixer_ctl *ctl, unsigned int id)
+{
+    struct snd_ctl_elem_value ev;
+
+    if ((ctl->info->type != SNDRV_CTL_ELEM_TYPE_ENUMERATED) ||
+        (id >= ctl->info->value.enumerated.items)) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    memset(&ev, 0, sizeof(ev));
+    ev.value.enumerated.item[0] = id;
+    ev.id.numid = ctl->info->id.numid;
+    if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_WRITE, &ev) < 0)
+        return -1;
+    return 0;
+}
+
+int mixer_ctl_set_enum_by_name(struct mixer_ctl *ctl, const char *string)
+{
+    unsigned int n, max;
+    struct snd_ctl_elem_value ev;
+    
+    if (ctl->info->type != SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
+        errno = EINVAL;
+        return -1;
+    }
+    
+    max = ctl->info->value.enumerated.items;
+    for (n = 0; n < max; n++) {
+        if (!strcmp(string, ctl->ename[n])) {
+            memset(&ev, 0, sizeof(ev));
+            ev.value.enumerated.item[0] = n;
+            ev.id.numid = ctl->info->id.numid;
+            if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_WRITE, &ev) < 0)
+                return -1;
+            return 0;
+        }
+    }
+    
+    errno = EINVAL;
+    return -1;
+}