tizen 2.3.1 release

[external/alsa-lib.git] / src / control / control.c

diff --git a/src/control/control.c b/src/control/control.c
index 19e9389..a0965c6 100644 (file)
--- a/src/control/control.c
+++ b/src/control/control.c
@@ -42,6 +42,7 @@ and IEC958 structure.
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include <stdarg.h>
 #include <unistd.h>
 #include <string.h>
@@ -359,6 +360,74 @@ int snd_ctl_elem_add_boolean(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
 }
 
 /**
+ * \brief Create and add a user-defined control element of type enumerated.
+ * \param[in] ctl Control device handle.
+ * \param[in] id ID of the new control element.
+ * \param[in] count Number of element values.
+ * \param[in] items Range of possible values (0 ... \a items - 1).
+ * \param[in] names An array containing \a items strings.
+ * \return Zero on success, otherwise a negative error code.
+ *
+ * This function creates a user element, i.e., a control element that is not
+ * controlled by the control device's driver but that is just stored together
+ * with the other elements of \a ctl.
+ *
+ * The fields of \a id, except numid, must be set to unique values that
+ * identify the new element.
+ *
+ * The new element is locked; its value is initialized as zero.
+ *
+ * \par Errors:
+ * <dl>
+ * <dt>-EBUSY<dd>A control element with ID \a id already exists.
+ * <dt>-EINVAL<dd>\a count is not at least one or greater than 128, or \a items
+ *     is not at least one, or a string in \a names is empty or longer than 63
+ *     bytes, or the strings in \a names require more than 64 KB storage.
+ * <dt>-ENOMEM<dd>Out of memory, or there are too many user control elements.
+ * <dt>-ENXIO<dd>This driver does not support (enumerated) user controls.
+ * <dt>-ENODEV<dd>Device unplugged.
+ * </dl>
+ *
+ * \par Compatibility:
+ * snd_ctl_elem_add_enumerated() was introduced in ALSA 1.0.25.
+ */
+int snd_ctl_elem_add_enumerated(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
+                               unsigned int count, unsigned int items,
+                               const char *const names[])
+{
+       snd_ctl_elem_info_t *info;
+       unsigned int i, bytes;
+       char *buf, *p;
+       int err;
+
+       assert(ctl && id && id->name[0] && names);
+
+       snd_ctl_elem_info_alloca(&info);
+       info->id = *id;
+       info->type = SND_CTL_ELEM_TYPE_ENUMERATED;
+       info->count = count;
+       info->value.enumerated.items = items;
+
+       bytes = 0;
+       for (i = 0; i < items; ++i)
+               bytes += strlen(names[i]) + 1;
+       buf = malloc(bytes);
+       if (!buf)
+               return -ENOMEM;
+       info->value.enumerated.names_ptr = (uintptr_t)buf;
+       info->value.enumerated.names_length = bytes;
+       p = buf;
+       for (i = 0; i < items; ++i)
+               p = stpcpy(p, names[i]) + 1;
+
+       err = ctl->ops->element_add(ctl, info);
+
+       free(buf);
+
+       return err;
+}
+
+/**
  * \brief Create and add an user IEC958 CTL element
  * \param ctl CTL handle
  * \param id CTL element info to add
@@ -919,6 +988,28 @@ int snd_ctl_open_lconf(snd_ctl_t **ctlp, const char *name,
        return snd_ctl_open_noupdate(ctlp, lconf, name, mode);
 }
 
+/**
+ * \brief Opens a fallback CTL
+ * \param ctlp Returned CTL handle
+ * \param root Configuration root
+ * \param name ASCII identifier of the CTL handle used as fallback
+ * \param orig_name The original ASCII name
+ * \param mode Open mode (see #SND_CTL_NONBLOCK, #SND_CTL_ASYNC)
+ * \return 0 on success otherwise a negative error code
+ */
+int snd_ctl_open_fallback(snd_ctl_t **ctlp, snd_config_t *root,
+                         const char *name, const char *orig_name, int mode)
+{
+       int err;
+       assert(ctlp && name && root);
+       err = snd_ctl_open_noupdate(ctlp, root, name, mode);
+       if (err >= 0) {
+               free((*ctlp)->name);
+               (*ctlp)->name = orig_name ? strdup(orig_name) : NULL;
+       }
+       return err;
+}
+
 #ifndef DOC_HIDDEN
 #define TYPE(v) [SND_CTL_ELEM_TYPE_##v] = #v
 #define IFACE(v) [SND_CTL_ELEM_IFACE_##v] = #v