ALSA: firewire-lib: rename parameter setting function for AM824 with FDF field

[cascardo/linux.git] / sound / firewire / amdtp-am824.c

diff --git a/sound/firewire/amdtp-am824.c b/sound/firewire/amdtp-am824.c
index da4b643..f5edcbf 100644 (file)
--- a/sound/firewire/amdtp-am824.c
+++ b/sound/firewire/amdtp-am824.c
@@ -10,6 +10,48 @@
 
 #define CIP_FMT_AM             0x10
 
+/* "Clock-based rate control mode" is just supported. */
+#define AMDTP_FDF_AM824                0x00
+
+/**
+ * amdtp_am824_set_parameters - set stream parameters
+ * @s: the AMDTP stream to configure
+ * @rate: the sample rate
+ * @pcm_channels: the number of PCM samples in each data block, to be encoded
+ *                as AM824 multi-bit linear audio
+ * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
+ * @double_pcm_frames: one data block transfers two PCM frames
+ *
+ * The parameters must be set before the stream is started, and must not be
+ * changed while the stream is running.
+ */
+int amdtp_am824_set_parameters(struct amdtp_stream *s, unsigned int rate,
+                              unsigned int pcm_channels,
+                              unsigned int midi_ports,
+                              bool double_pcm_frames)
+{
+       int err;
+
+       err = amdtp_stream_set_parameters(s, rate, pcm_channels, midi_ports);
+       if (err < 0)
+               return err;
+
+       s->fdf = AMDTP_FDF_AM824 | s->sfc;
+
+       /*
+        * In IEC 61883-6, one data block represents one event. In ALSA, one
+        * event equals to one PCM frame. But Dice has a quirk at higher
+        * sampling rate to transfer two PCM frames in one data block.
+        */
+       if (double_pcm_frames)
+               s->frame_multiplier = 2;
+       else
+               s->frame_multiplier = 1;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(amdtp_am824_set_parameters);
+
 /**
  * amdtp_am824_init - initialize an AMDTP stream structure to handle AM824
  *                   data block