linux/sound/firewire/tascam/amdtp-tascam.c

186 lines
4.4 KiB
C

/*
* amdtp-tascam.c - a part of driver for TASCAM FireWire series
*
* Copyright (c) 2015 Takashi Sakamoto
*
* Licensed under the terms of the GNU General Public License, version 2.
*/
#include <sound/pcm.h>
#include "tascam.h"
#define AMDTP_FMT_TSCM_TX 0x1e
#define AMDTP_FMT_TSCM_RX 0x3e
struct amdtp_tscm {
unsigned int pcm_channels;
};
int amdtp_tscm_set_parameters(struct amdtp_stream *s, unsigned int rate)
{
struct amdtp_tscm *p = s->protocol;
unsigned int data_channels;
if (amdtp_stream_running(s))
return -EBUSY;
data_channels = p->pcm_channels;
/* Packets in in-stream have extra 2 data channels. */
if (s->direction == AMDTP_IN_STREAM)
data_channels += 2;
return amdtp_stream_set_parameters(s, rate, data_channels);
}
static void write_pcm_s32(struct amdtp_stream *s,
struct snd_pcm_substream *pcm,
__be32 *buffer, unsigned int frames)
{
struct amdtp_tscm *p = s->protocol;
struct snd_pcm_runtime *runtime = pcm->runtime;
unsigned int channels, remaining_frames, i, c;
const u32 *src;
channels = p->pcm_channels;
src = (void *)runtime->dma_area +
frames_to_bytes(runtime, s->pcm_buffer_pointer);
remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
for (i = 0; i < frames; ++i) {
for (c = 0; c < channels; ++c) {
buffer[c] = cpu_to_be32(*src);
src++;
}
buffer += s->data_block_quadlets;
if (--remaining_frames == 0)
src = (void *)runtime->dma_area;
}
}
static void read_pcm_s32(struct amdtp_stream *s,
struct snd_pcm_substream *pcm,
__be32 *buffer, unsigned int frames)
{
struct amdtp_tscm *p = s->protocol;
struct snd_pcm_runtime *runtime = pcm->runtime;
unsigned int channels, remaining_frames, i, c;
u32 *dst;
channels = p->pcm_channels;
dst = (void *)runtime->dma_area +
frames_to_bytes(runtime, s->pcm_buffer_pointer);
remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
/* The first data channel is for event counter. */
buffer += 1;
for (i = 0; i < frames; ++i) {
for (c = 0; c < channels; ++c) {
*dst = be32_to_cpu(buffer[c]);
dst++;
}
buffer += s->data_block_quadlets;
if (--remaining_frames == 0)
dst = (void *)runtime->dma_area;
}
}
static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
unsigned int data_blocks)
{
struct amdtp_tscm *p = s->protocol;
unsigned int channels, i, c;
channels = p->pcm_channels;
for (i = 0; i < data_blocks; ++i) {
for (c = 0; c < channels; ++c)
buffer[c] = 0x00000000;
buffer += s->data_block_quadlets;
}
}
int amdtp_tscm_add_pcm_hw_constraints(struct amdtp_stream *s,
struct snd_pcm_runtime *runtime)
{
int err;
/*
* Our implementation allows this protocol to deliver 24 bit sample in
* 32bit data channel.
*/
err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
if (err < 0)
return err;
return amdtp_stream_add_pcm_hw_constraints(s, runtime);
}
static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
__be32 *buffer,
unsigned int data_blocks,
unsigned int *syt)
{
struct snd_pcm_substream *pcm;
pcm = ACCESS_ONCE(s->pcm);
if (data_blocks > 0 && pcm)
read_pcm_s32(s, pcm, buffer, data_blocks);
/* A place holder for control messages. */
return data_blocks;
}
static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
__be32 *buffer,
unsigned int data_blocks,
unsigned int *syt)
{
struct snd_pcm_substream *pcm;
/* This field is not used. */
*syt = 0x0000;
pcm = ACCESS_ONCE(s->pcm);
if (pcm)
write_pcm_s32(s, pcm, buffer, data_blocks);
else
write_pcm_silence(s, buffer, data_blocks);
return data_blocks;
}
int amdtp_tscm_init(struct amdtp_stream *s, struct fw_unit *unit,
enum amdtp_stream_direction dir, unsigned int pcm_channels)
{
amdtp_stream_process_data_blocks_t process_data_blocks;
struct amdtp_tscm *p;
unsigned int fmt;
int err;
if (dir == AMDTP_IN_STREAM) {
fmt = AMDTP_FMT_TSCM_TX;
process_data_blocks = process_tx_data_blocks;
} else {
fmt = AMDTP_FMT_TSCM_RX;
process_data_blocks = process_rx_data_blocks;
}
err = amdtp_stream_init(s, unit, dir,
CIP_NONBLOCKING | CIP_SKIP_DBC_ZERO_CHECK, fmt,
process_data_blocks, sizeof(struct amdtp_tscm));
if (err < 0)
return 0;
/* Use fixed value for FDF field. */
s->fdf = 0x00;
/* This protocol uses fixed number of data channels for PCM samples. */
p = s->protocol;
p->pcm_channels = pcm_channels;
return 0;
}