fix doc errors

Fix various errors in the documentation that make doxygen complain.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

src/pcm/pcm.c

@@ -2460,8 +2460,8 @@ snd_pcm_sframes_t snd_pcm_avail(snd_pcm_t *pcm)
 /**
  * \brief Combine snd_pcm_avail and snd_pcm_delay functions
  * \param pcm PCM handle
- * \param avail Number of available frames in the ring buffer
- * \param delay Total I/O latency in frames
+ * \param availp Number of available frames in the ring buffer
+ * \param delayp Total I/O latency in frames
  * \return zero on success otherwise a negative error code
  *
  * The avail and delay values retuned are in sync.

src/pcm/pcm_dmix.c

@@ -145,9 +145,11 @@ static void dmix_server_free(snd_pcm_direct_t *dmix)
 #elif defined(__x86_64__)
 #include "pcm_dmix_x86_64.c"
 #else
+#ifndef DOC_HIDDEN
 #define mix_select_callbacks(x)	generic_mix_select_callbacks(x)
 #define dmix_supported_format generic_dmix_supported_format
 #endif
+#endif
 
 static void mix_areas(snd_pcm_direct_t *dmix,
 		      const snd_pcm_channel_area_t *src_areas,

src/pcm/pcm_ioplug.c

@@ -877,7 +877,7 @@ callback.
 Finally, the dump callback is used to print the status of the plugin.
 
 The hw_params constraints can be defined via either
-#snd_pcm_iplug_set_param_minmax() and #snd_pcm_ioplug_set_param_list()
+#snd_pcm_ioplug_set_param_minmax() and #snd_pcm_ioplug_set_param_list()
 functions after calling #snd_pcm_ioplug_create().
 The former defines the minimal and maximal acceptable values for the
 given hw_params parameter (SND_PCM_IOPLUG_HW_XXX).

src/pcm/pcm_mmap_emul.c

@@ -34,6 +34,7 @@
 const char *_snd_module_pcm_mmap_emul = "";
 #endif
 
+#ifndef DOC_HIDDEN
 /*
  *
  */
@@ -44,6 +45,7 @@ typedef struct {
 	snd_pcm_uframes_t hw_ptr;
 	snd_pcm_uframes_t appl_ptr;
 } mmap_emul_t;
+#endif
 
 /*
  * here goes a really tricky part; hw_refine falls back to ACCESS_RW_* type

src/pcm/pcm_rate.c

@@ -1326,7 +1326,7 @@ static int rate_open_func(snd_pcm_rate_t *rate, const char *type)
  * \param name Name of PCM
  * \param sformat Slave format
  * \param srate Slave rate
- * \param type SRC type string
+ * \param converter SRC type string node
  * \param slave Slave PCM handle
  * \param close_slave When set, the slave PCM handle is closed with copy PCM
  * \retval zero on success otherwise a negative error code