Initial import

1 files changed, 177 insertions, 0 deletions

diff --git a/include/sound/pcm-indirect.h b/include/sound/pcm-indirect.h
new file mode 100644
index 000000000..1df7acaaa
--- /dev/null
+++ b/include/sound/pcm-indirect.h
@@ -0,0 +1,177 @@
+/*
+ * Helper functions for indirect PCM data transfer
+ *
+ *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
+ *                   Jaroslav Kysela <perex@perex.cz>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __SOUND_PCM_INDIRECT_H
+#define __SOUND_PCM_INDIRECT_H
+
+#include <sound/pcm.h>
+
+struct snd_pcm_indirect {
+	unsigned int hw_buffer_size;	/* Byte size of hardware buffer */
+	unsigned int hw_queue_size;	/* Max queue size of hw buffer (0 = buffer size) */
+	unsigned int hw_data;	/* Offset to next dst (or src) in hw ring buffer */
+	unsigned int hw_io;	/* Ring buffer hw pointer */
+	int hw_ready;		/* Bytes ready for play (or captured) in hw ring buffer */
+	unsigned int sw_buffer_size;	/* Byte size of software buffer */
+	unsigned int sw_data;	/* Offset to next dst (or src) in sw ring buffer */
+	unsigned int sw_io;	/* Current software pointer in bytes */
+	int sw_ready;		/* Bytes ready to be transferred to/from hw */
+	snd_pcm_uframes_t appl_ptr;	/* Last seen appl_ptr */
+};
+
+typedef void (*snd_pcm_indirect_copy_t)(struct snd_pcm_substream *substream,
+					struct snd_pcm_indirect *rec, size_t bytes);
+
+/*
+ * helper function for playback ack callback
+ */
+static inline void
+snd_pcm_indirect_playback_transfer(struct snd_pcm_substream *substream,
+				   struct snd_pcm_indirect *rec,
+				   snd_pcm_indirect_copy_t copy)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr;
+	snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr;
+	int qsize;
+
+	if (diff) {
+		if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2))
+			diff += runtime->boundary;
+		rec->sw_ready += (int)frames_to_bytes(runtime, diff);
+		rec->appl_ptr = appl_ptr;
+	}
+	qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size;
+	while (rec->hw_ready < qsize && rec->sw_ready > 0) {
+		unsigned int hw_to_end = rec->hw_buffer_size - rec->hw_data;
+		unsigned int sw_to_end = rec->sw_buffer_size - rec->sw_data;
+		unsigned int bytes = qsize - rec->hw_ready;
+		if (rec->sw_ready < (int)bytes)
+			bytes = rec->sw_ready;
+		if (hw_to_end < bytes)
+			bytes = hw_to_end;
+		if (sw_to_end < bytes)
+			bytes = sw_to_end;
+		if (! bytes)
+			break;
+		copy(substream, rec, bytes);
+		rec->hw_data += bytes;
+		if (rec->hw_data == rec->hw_buffer_size)
+			rec->hw_data = 0;
+		rec->sw_data += bytes;
+		if (rec->sw_data == rec->sw_buffer_size)
+			rec->sw_data = 0;
+		rec->hw_ready += bytes;
+		rec->sw_ready -= bytes;
+	}
+}
+
+/*
+ * helper function for playback pointer callback
+ * ptr = current byte pointer
+ */
+static inline snd_pcm_uframes_t
+snd_pcm_indirect_playback_pointer(struct snd_pcm_substream *substream,
+				  struct snd_pcm_indirect *rec, unsigned int ptr)
+{
+	int bytes = ptr - rec->hw_io;
+	if (bytes < 0)
+		bytes += rec->hw_buffer_size;
+	rec->hw_io = ptr;
+	rec->hw_ready -= bytes;
+	rec->sw_io += bytes;
+	if (rec->sw_io >= rec->sw_buffer_size)
+		rec->sw_io -= rec->sw_buffer_size;
+	if (substream->ops->ack)
+		substream->ops->ack(substream);
+	return bytes_to_frames(substream->runtime, rec->sw_io);
+}
+
+
+/*
+ * helper function for capture ack callback
+ */
+static inline void
+snd_pcm_indirect_capture_transfer(struct snd_pcm_substream *substream,
+				  struct snd_pcm_indirect *rec,
+				  snd_pcm_indirect_copy_t copy)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr;
+	snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr;
+
+	if (diff) {
+		if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2))
+			diff += runtime->boundary;
+		rec->sw_ready -= frames_to_bytes(runtime, diff);
+		rec->appl_ptr = appl_ptr;
+	}
+	while (rec->hw_ready > 0 && 
+	       rec->sw_ready < (int)rec->sw_buffer_size) {
+		size_t hw_to_end = rec->hw_buffer_size - rec->hw_data;
+		size_t sw_to_end = rec->sw_buffer_size - rec->sw_data;
+		size_t bytes = rec->sw_buffer_size - rec->sw_ready;
+		if (rec->hw_ready < (int)bytes)
+			bytes = rec->hw_ready;
+		if (hw_to_end < bytes)
+			bytes = hw_to_end;
+		if (sw_to_end < bytes)
+			bytes = sw_to_end;
+		if (! bytes)
+			break;
+		copy(substream, rec, bytes);
+		rec->hw_data += bytes;
+		if ((int)rec->hw_data == rec->hw_buffer_size)
+			rec->hw_data = 0;
+		rec->sw_data += bytes;
+		if (rec->sw_data == rec->sw_buffer_size)
+			rec->sw_data = 0;
+		rec->hw_ready -= bytes;
+		rec->sw_ready += bytes;
+	}
+}
+
+/*
+ * helper function for capture pointer callback,
+ * ptr = current byte pointer
+ */
+static inline snd_pcm_uframes_t
+snd_pcm_indirect_capture_pointer(struct snd_pcm_substream *substream,
+				 struct snd_pcm_indirect *rec, unsigned int ptr)
+{
+	int qsize;
+	int bytes = ptr - rec->hw_io;
+	if (bytes < 0)
+		bytes += rec->hw_buffer_size;
+	rec->hw_io = ptr;
+	rec->hw_ready += bytes;
+	qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size;
+	if (rec->hw_ready > qsize)
+		return SNDRV_PCM_POS_XRUN;
+	rec->sw_io += bytes;
+	if (rec->sw_io >= rec->sw_buffer_size)
+		rec->sw_io -= rec->sw_buffer_size;
+	if (substream->ops->ack)
+		substream->ops->ack(substream);
+	return bytes_to_frames(substream->runtime, rec->sw_io);
+}
+
+#endif /* __SOUND_PCM_INDIRECT_H */