nwz/alsa: various improvements

Also audiohw driver to specific device name, rewrite alsa controls code to
cache more data, thus making the code easier and use less stack. Avoid using
short/long in pcm alsa code since it's the wrong size on 64-bit (simulator
for example)

Change-Id: Ibc1ec44396e37b6cbdedbcf37300878638e5d2d3

1 files changed, 103 insertions, 64 deletions

diff --git a/firmware/target/hosted/alsa-controls.c b/firmware/target/hosted/alsa-controls.c
index f4914aa216..8d8c46decd 100644
--- a/firmware/target/hosted/alsa-controls.c
+++ b/firmware/target/hosted/alsa-controls.c
@@ -19,33 +19,108 @@
  ****************************************************************************/
 #include "alsa-controls.h"
 #include "panic.h"
+#include "debug.h"
 #include <stdlib.h>
 
 /* alsa control handle, we keep it open at all times */
 static snd_ctl_t *alsa_ctl;
 /* list of all controls, we allocate and fill it once, so we can easily lookup */
 static snd_ctl_elem_list_t *alsa_ctl_list;
+static unsigned alsa_ctl_count;
+/* for each control, we store some info to avoid constantly using ALSA's horrible lookup functions */
+static struct ctl_t
+{
+    snd_ctl_elem_id_t *id; /* ID associated with the control */
+    const char *name; /* name of the control */
+    snd_ctl_elem_type_t type; /* control type (boolean, enum, ...) */
+    unsigned count; /* dimension of the control */
+    unsigned items; /* number of items (for enums) */
+    const char **enum_name; /* names of the enum, indexed by ALSA index */
+} *alsa_ctl_info;
 
-void alsa_controls_init(void)
+#if defined(DEBUG)
+static const char *alsa_ctl_type_name(snd_ctl_elem_type_t type)
+{
+    switch(type)
+    {
+        case SND_CTL_ELEM_TYPE_BOOLEAN: return "BOOLEAN";
+        case SND_CTL_ELEM_TYPE_INTEGER: return "INTEGER";
+        case SND_CTL_ELEM_TYPE_ENUMERATED: return "ENUMERATED";
+        default: return "???";
+    }
+}
+#endif
+
+void alsa_controls_init(const char *name)
 {
-    snd_ctl_elem_info_t *info;
     /* allocate list on heap because it is used it is used in other functions */
     snd_ctl_elem_list_malloc(&alsa_ctl_list);
-    /* allocate info on stack so there is no need to free them */
-    snd_ctl_elem_info_alloca(&info);
     /* there is only one card and "default" always works */
-    if(snd_ctl_open(&alsa_ctl, "default", 0) < 0)
+    if(snd_ctl_open(&alsa_ctl, name, 0) < 0)
         panicf("Cannot open ctl\n");
     /* ALSA is braindead: first "get" the list -> only retrieve count */
     if(snd_ctl_elem_list(alsa_ctl, alsa_ctl_list) < 0)
         panicf("Cannot get element list\n");
     /* now we can allocate the list since the know the size */
-    int count = snd_ctl_elem_list_get_count(alsa_ctl_list);
-    if(snd_ctl_elem_list_alloc_space(alsa_ctl_list, count) < 0)
+    alsa_ctl_count = snd_ctl_elem_list_get_count(alsa_ctl_list);
+    if(snd_ctl_elem_list_alloc_space(alsa_ctl_list, alsa_ctl_count) < 0)
         panicf("Cannot allocate space for element list\n");
     /* ... and get the list again! */
     if(snd_ctl_elem_list(alsa_ctl, alsa_ctl_list) < 0)
         panicf("Cannot get element list\n");
+    /* now cache the info */
+    alsa_ctl_info = malloc(sizeof(struct ctl_t) * alsa_ctl_count);
+    snd_ctl_elem_info_t *info;
+    snd_ctl_elem_info_malloc(&info);
+    for(unsigned i = 0; i < alsa_ctl_count; i++)
+    {
+        /* allocate the ID and retrieve it */
+        snd_ctl_elem_id_malloc(&alsa_ctl_info[i].id);
+        snd_ctl_elem_list_get_id(alsa_ctl_list, i, alsa_ctl_info[i].id);
+        /* NOTE: name is valid as long as the ID lives; since we keep both, no need to copy */
+        alsa_ctl_info[i].name = snd_ctl_elem_id_get_name(alsa_ctl_info[i].id);
+        /* get info */
+        snd_ctl_elem_info_set_id(info, alsa_ctl_info[i].id);
+        if(snd_ctl_elem_info(alsa_ctl, info) < 0)
+            panicf("Cannot get control '%s' info", alsa_ctl_info[i].name);
+        alsa_ctl_info[i].type = snd_ctl_elem_info_get_type(info);
+        alsa_ctl_info[i].count = snd_ctl_elem_info_get_count(info);
+        if(alsa_ctl_info[i].type == SND_CTL_ELEM_TYPE_ENUMERATED)
+        {
+            alsa_ctl_info[i].items = snd_ctl_elem_info_get_items(info);
+            alsa_ctl_info[i].enum_name = malloc(sizeof(char *) * alsa_ctl_info[i].items);
+            for(unsigned j = 0; j < alsa_ctl_info[i].items; j++)
+            {
+                snd_ctl_elem_info_set_item(info, j);
+                if(snd_ctl_elem_info(alsa_ctl, info) < 0)
+                    panicf("Cannot get control '%s' info for item %u", alsa_ctl_info[i].name, j);
+                /* NOTE: copy string because it becomes invalid after info is freed */
+                alsa_ctl_info[i].enum_name[j] = strdup(snd_ctl_elem_info_get_item_name(info));
+            }
+        }
+        else
+            alsa_ctl_info[i].items = 0;
+    }
+    snd_ctl_elem_info_free(info);
+
+    DEBUGF("ALSA controls:\n");
+    for(unsigned i = 0; i < alsa_ctl_count; i++)
+    {
+        DEBUGF("- name='%s', type=%s, count=%u\n", alsa_ctl_info[i].name,
+            alsa_ctl_type_name(alsa_ctl_info[i].type), alsa_ctl_info[i].count);
+        if(alsa_ctl_info[i].type == SND_CTL_ELEM_TYPE_ENUMERATED)
+        {
+            DEBUGF("  items:");
+            for(unsigned j = 0; j < alsa_ctl_info[i].items; j++)
+            {
+                if(j != 0)
+                    DEBUGF(",");
+                DEBUGF(" '%s'", alsa_ctl_info[i].enum_name[j]);
+            }
+            DEBUGF("\n");
+        }
+    }
+
 }
 
 void alsa_controls_close(void)
@@ -53,56 +128,33 @@ void alsa_controls_close(void)
     snd_ctl_close(alsa_ctl);
 }
 
-/* find a control element ID by name, return false of not found, the id needs
- * to be allocated */
-bool alsa_controls_find(snd_ctl_elem_id_t *id, const char *name)
+/* find a control element ID by name, return -1 of not found or index into array */
+int alsa_controls_find(const char *name)
 {
-    /* ALSA identifies controls by "id"s, it almost makes sense, except ids
-     * are a horrible opaque structure */
-    int count = snd_ctl_elem_list_get_count(alsa_ctl_list);
     /* enumerate controls */
-    for(int i = 0; i < count; i++)
-    {
-        snd_ctl_elem_list_get_id(alsa_ctl_list, i, id);
-
-        if(strcmp(snd_ctl_elem_id_get_name(id), name) == 0)
-            return true;
-    }
+    for(unsigned i = 0; i < alsa_ctl_count; i++)
+        if(strcmp(alsa_ctl_info[i].name, name) == 0)
+            return i;
     /* not found */
-    return false;
+    return -1;
 }
 
 bool alsa_has_control(const char *name)
 {
-    snd_ctl_elem_id_t *id;
-    /* allocate things on stack */
-    snd_ctl_elem_id_alloca(&id);
-    /* find control */
-    return alsa_controls_find(id, name);
+    return alsa_controls_find(name) >= 0;
 }
 
 /* find a control element enum index by name, return -1 if not found */
 int alsa_controls_find_enum(const char *name, const char *enum_name)
 {
-    snd_ctl_elem_id_t *id;
-    snd_ctl_elem_info_t *info;
-    /* allocate things on stack to speedup */
-    snd_ctl_elem_id_alloca(&id);
-    snd_ctl_elem_info_alloca(&info);
     /* find control */
-    if(!alsa_controls_find(id, name))
+    int idx = alsa_controls_find(name);
+    if(idx < 0)
         panicf("Cannot find control '%s'", name);
-    snd_ctl_elem_info_set_id(info, id);
-    if(snd_ctl_elem_info(alsa_ctl, info) < 0)
-        panicf("Cannot get control '%s' info", name);
     /* list items */
-    unsigned count = snd_ctl_elem_info_get_items(info);
-    for(unsigned i = 0; i < count; i++)
+    for(unsigned i = 0; i < alsa_ctl_info[idx].items; i++)
     {
-        snd_ctl_elem_info_set_item(info, i);
-        if(snd_ctl_elem_info(alsa_ctl, info) < 0)
-            panicf("Cannot get control '%s' info for item %u", name, i);
-        if(strcmp(snd_ctl_elem_info_get_item_name(info), enum_name) == 0)
+        if(strcmp(alsa_ctl_info[idx].enum_name[i], enum_name) == 0)
             return i;
     }
     return -1;
@@ -112,27 +164,21 @@ int alsa_controls_find_enum(const char *name, const char *enum_name)
 void alsa_controls_get_set(bool get, const char *name, snd_ctl_elem_type_t type,
     unsigned nr_values, long *val)
 {
-    snd_ctl_elem_id_t *id;
-    snd_ctl_elem_info_t *info;
     snd_ctl_elem_value_t *value;
     /* allocate things on stack to speedup */
-    snd_ctl_elem_id_alloca(&id);
-    snd_ctl_elem_info_alloca(&info);
     snd_ctl_elem_value_alloca(&value);
     /* find control */
-    if(!alsa_controls_find(id, name))
+    int idx = alsa_controls_find(name);
+    if(idx < 0)
         panicf("Cannot find control '%s'", name);
     /* check the type of the control */
-    snd_ctl_elem_info_set_id(info, id);
-    if(snd_ctl_elem_info(alsa_ctl, info) < 0)
-        panicf("Cannot get control '%s' info", name);
-    if(snd_ctl_elem_info_get_type(info) != type)
+    if(alsa_ctl_info[idx].type != type)
         panicf("Control '%s' has wrong type (got %d, expected %d", name,
-            snd_ctl_elem_info_get_type(info), type);
-    if(snd_ctl_elem_info_get_count(info) != nr_values)
+            alsa_ctl_info[idx].type, type);
+    if(alsa_ctl_info[idx].count != nr_values)
         panicf("Control '%s' has wrong count (got %u, expected %u)",
-            name, snd_ctl_elem_info_get_count(info), nr_values);
-    snd_ctl_elem_value_set_id(value, id);
+            name, alsa_ctl_info[idx].count, nr_values);
+    snd_ctl_elem_value_set_id(value, alsa_ctl_info[idx].id);
     /* set value */
     if(get)
     {
@@ -185,19 +231,12 @@ void alsa_controls_get(const char *name, snd_ctl_elem_type_t type,
 /* get control information */
 void alsa_controls_get_info(const char *name, int *out_count)
 {
-    snd_ctl_elem_id_t *id;
-    snd_ctl_elem_info_t *info;
-    /* allocate things on stack to speedup */
-    snd_ctl_elem_id_alloca(&id);
-    snd_ctl_elem_info_alloca(&info);
     /* find control */
-    if(!alsa_controls_find(id, name))
+    int idx = alsa_controls_find(name);
+    if(idx < 0)
         panicf("Cannot find control '%s'", name);
     /* get info */
-    snd_ctl_elem_info_set_id(info, id);
-    if(snd_ctl_elem_info(alsa_ctl, info) < 0)
-        panicf("Cannot get control '%s' info", name);
-    *out_count = snd_ctl_elem_info_get_count(info);
+    *out_count = alsa_ctl_info[idx].count;
 }
 
 /* helper function: set a control with a single boolean value */