ALSA: hda - Add hint string helper functions

Added snd_hda_get_hint() and snd_hda_get_bool_hint() helper functions
to retrieve a hint value.

Internally, the hint is stored in a pair of two strings, key and val.

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

diff --git a/sound/pci/hda/hda_hwdep.c b/sound/pci/hda/hda_hwdep.c
index 4af484b8240cde92a39a3010cbe69f39bec4abf0..5e554de9cd9bb25e7e38e6b4c4fae44fc1d76dc6 100644 (file)
--- a/sound/pci/hda/hda_hwdep.c
+++ b/sound/pci/hda/hda_hwdep.c
@@ -30,6 +30,12 @@
 #include <sound/hda_hwdep.h>
 #include <sound/minors.h>
 
+/* hint string pair */
+struct hda_hint {
+       const char *key;
+       const char *val;        /* contained in the same alloc as key */
+};
+
 /*
  * write/read an out-of-bound verb
  */
@@ -99,15 +105,15 @@ static int hda_hwdep_open(struct snd_hwdep *hw, struct file *file)
 
 static void clear_hwdep_elements(struct hda_codec *codec)
 {
-       char **head;
        int i;
 
        /* clear init verbs */
        snd_array_free(&codec->init_verbs);
        /* clear hints */
-       head = codec->hints.list;
-       for (i = 0; i < codec->hints.used; i++, head++)
-               kfree(*head);
+       for (i = 0; i < codec->hints.used; i++) {
+               struct hda_hint *hint = snd_array_elem(&codec->hints, i);
+               kfree(hint->key); /* we don't need to free hint->val */
+       }
        snd_array_free(&codec->hints);
        snd_array_free(&codec->user_pins);
 }
@@ -141,7 +147,7 @@ int /*__devinit*/ snd_hda_create_hwdep(struct hda_codec *codec)
 #endif
 
        snd_array_init(&codec->init_verbs, sizeof(struct hda_verb), 32);
-       snd_array_init(&codec->hints, sizeof(char *), 32);
+       snd_array_init(&codec->hints, sizeof(struct hda_hint), 32);
        snd_array_init(&codec->user_pins, sizeof(struct hda_pincfg), 16);
 
        return 0;
@@ -306,26 +312,81 @@ static ssize_t init_verbs_store(struct device *dev,
        return count;
 }
 
+static struct hda_hint *get_hint(struct hda_codec *codec, const char *key)
+{
+       int i;
+
+       for (i = 0; i < codec->hints.used; i++) {
+               struct hda_hint *hint = snd_array_elem(&codec->hints, i);
+               if (!strcmp(hint->key, key))
+                       return hint;
+       }
+       return NULL;
+}
+
+static void remove_trail_spaces(char *str)
+{
+       char *p;
+       if (!*str)
+               return;
+       p = str + strlen(str) - 1;
+       for (; isspace(*p); p--) {
+               *p = 0;
+               if (p == str)
+                       return;
+       }
+}
+
+#define MAX_HINTS      1024
+
 static ssize_t hints_store(struct device *dev,
                           struct device_attribute *attr,
                           const char *buf, size_t count)
 {
        struct snd_hwdep *hwdep = dev_get_drvdata(dev);
        struct hda_codec *codec = hwdep->private_data;
-       char *p;
-       char **hint;
+       char *key, *val;
+       struct hda_hint *hint;
 
-       if (!*buf || isspace(*buf) || *buf == '#' || *buf == '\n')
+       while (isspace(*buf))
+               buf++;
+       if (!*buf || *buf == '#' || *buf == '\n')
                return count;
-       p = kstrndup_noeol(buf, 1024);
-       if (!p)
+       if (*buf == '=')
+               return -EINVAL;
+       key = kstrndup_noeol(buf, 1024);
+       if (!key)
                return -ENOMEM;
-       hint = snd_array_new(&codec->hints);
+       /* extract key and val */
+       val = strchr(key, '=');
+       if (!val) {
+               kfree(key);
+               return -EINVAL;
+       }
+       *val++ = 0;
+       while (isspace(*val))
+               val++;
+       remove_trail_spaces(key);
+       remove_trail_spaces(val);
+       hint = get_hint(codec, key);
+       if (hint) {
+               /* replace */
+               kfree(hint->key);
+               hint->key = key;
+               hint->val = val;
+               return count;
+       }
+       /* allocate a new hint entry */
+       if (codec->hints.used >= MAX_HINTS)
+               hint = NULL;
+       else
+               hint = snd_array_new(&codec->hints);
        if (!hint) {
-               kfree(p);
+               kfree(key);
                return -ENOMEM;
        }
-       *hint = p;
+       hint->key = key;
+       hint->val = val;
        return count;
 }
 
@@ -428,4 +489,29 @@ int snd_hda_hwdep_add_sysfs(struct hda_codec *codec)
        return 0;
 }
 
+/*
+ * Look for hint string
+ */
+const char *snd_hda_get_hint(struct hda_codec *codec, const char *key)
+{
+       struct hda_hint *hint = get_hint(codec, key);
+       return hint ? hint->val : NULL;
+}
+EXPORT_SYMBOL_HDA(snd_hda_get_hint);
+
+int snd_hda_get_bool_hint(struct hda_codec *codec, const char *key)
+{
+       const char *p = snd_hda_get_hint(codec, key);
+       if (!p || !*p)
+               return -ENOENT;
+       switch (toupper(*p)) {
+       case 'T': /* true */
+       case 'Y': /* yes */
+       case '1':
+               return 1;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_HDA(snd_hda_get_bool_hint);
+
 #endif /* CONFIG_SND_HDA_RECONFIG */

diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index 03ee9dd04913919ac16e29bf22f026023853d248..27428c718fd7199297fa07e78acc6c081d02c55f 100644 (file)
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -433,6 +433,23 @@ static inline int snd_hda_hwdep_add_sysfs(struct hda_codec *codec)
 }
 #endif
 
+#ifdef CONFIG_SND_HDA_RECONFIG
+const char *snd_hda_get_hint(struct hda_codec *codec, const char *key);
+int snd_hda_get_bool_hint(struct hda_codec *codec, const char *key);
+#else
+static inline
+const char *snd_hda_get_hint(struct hda_codec *codec, const char *key)
+{
+       return NULL;
+}
+
+static inline
+int snd_hda_get_bool_hint(struct hda_codec *codec, const char *key)
+{
+       return -ENOENT;
+}
+#endif
+
 /*
  * power-management
  */