us144mkii/playback.c

289 lines
9.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include "us144mkii.h"
#include "playback.h"
/**
* process_playback_routing_us144mkii() - Apply playback routing matrix
* @tascam: The driver instance.
* @src_buffer: Buffer containing 4 channels of S24_3LE audio from ALSA.
* @dst_buffer: Buffer to be filled for the USB device.
* @frames: Number of frames to process.
*/
void process_playback_routing_us144mkii(struct tascam_card *tascam,
const u8 *src_buffer,
u8 *dst_buffer, size_t frames)
{
size_t f;
const u8 *src_12, *src_34;
u8 *dst_line, *dst_digital;
for (f = 0; f < frames; ++f) {
src_12 = src_buffer + f * BYTES_PER_FRAME;
src_34 = src_12 + (2 * BYTES_PER_SAMPLE);
dst_line = dst_buffer + f * BYTES_PER_FRAME;
dst_digital = dst_line + (2 * BYTES_PER_SAMPLE);
/* LINE OUTPUTS (ch1/2 on device) */
if (tascam->line_out_source == 0) /* "ch1 and ch2" */
memcpy(dst_line, src_12, 2 * BYTES_PER_SAMPLE);
else /* "ch3 and ch4" */
memcpy(dst_line, src_34, 2 * BYTES_PER_SAMPLE);
/* DIGITAL OUTPUTS (ch3/4 on device) */
if (tascam->digital_out_source == 0) /* "ch1 and ch2" */
memcpy(dst_digital, src_12, 2 * BYTES_PER_SAMPLE);
else /* "ch3 and ch4" */
memcpy(dst_digital, src_34, 2 * BYTES_PER_SAMPLE);
}
}
/**
* playback_urb_complete() - Completion handler for playback isochronous URBs.
* @urb: the completed URB
*
* This function runs in interrupt context. It calculates the number of bytes
* to send in the next set of packets based on the feedback-driven clock,
* copies the audio data from the ALSA ring buffer (applying routing), and
* resubmits the URB.
*/
void playback_urb_complete(struct urb *urb)
{
struct tascam_card *tascam = urb->context;
struct snd_pcm_substream *substream;
struct snd_pcm_runtime *runtime;
unsigned long flags;
u8 *src_buf, *dst_buf;
size_t total_bytes_for_urb = 0;
snd_pcm_uframes_t offset_frames;
snd_pcm_uframes_t frames_to_copy;
int ret, i;
if (urb->status) {
if (urb->status != -ENOENT && urb->status != -ECONNRESET && urb->status != -ESHUTDOWN &&
urb->status != -ENODEV)
dev_err_ratelimited(tascam->card->dev, "Playback URB failed: %d\n", urb->status);
goto out;
}
if (!tascam || !atomic_read(&tascam->playback_active))
goto out;
substream = tascam->playback_substream;
if (!substream || !substream->runtime)
goto out;
runtime = substream->runtime;
spin_lock_irqsave(&tascam->lock, flags);
for (i = 0; i < urb->number_of_packets; i++) {
unsigned int frames_for_packet;
size_t bytes_for_packet;
if (tascam->feedback_synced) {
frames_for_packet = tascam->feedback_accumulator_pattern[tascam->feedback_pattern_out_idx];
tascam->feedback_pattern_out_idx = (tascam->feedback_pattern_out_idx + 1) % FEEDBACK_ACCUMULATOR_SIZE;
} else {
frames_for_packet = runtime->rate / 8000;
}
bytes_for_packet = frames_for_packet * BYTES_PER_FRAME;
urb->iso_frame_desc[i].offset = total_bytes_for_urb;
urb->iso_frame_desc[i].length = bytes_for_packet;
total_bytes_for_urb += bytes_for_packet;
}
urb->transfer_buffer_length = total_bytes_for_urb;
offset_frames = tascam->driver_playback_pos;
frames_to_copy = bytes_to_frames(runtime, total_bytes_for_urb);
tascam->driver_playback_pos = (offset_frames + frames_to_copy) % runtime->buffer_size;
spin_unlock_irqrestore(&tascam->lock, flags);
if (total_bytes_for_urb > 0) {
src_buf = runtime->dma_area + frames_to_bytes(runtime, offset_frames);
dst_buf = tascam->playback_routing_buffer;
/* Handle ring buffer wrap-around */
if (offset_frames + frames_to_copy > runtime->buffer_size) {
size_t first_chunk_bytes = frames_to_bytes(runtime, runtime->buffer_size - offset_frames);
size_t second_chunk_bytes = total_bytes_for_urb - first_chunk_bytes;
memcpy(dst_buf, src_buf, first_chunk_bytes);
memcpy(dst_buf + first_chunk_bytes, runtime->dma_area, second_chunk_bytes);
} else {
memcpy(dst_buf, src_buf, total_bytes_for_urb);
}
/* Apply routing to the contiguous data in our routing buffer */
process_playback_routing_us144mkii(tascam, dst_buf, dst_buf, frames_to_copy);
memcpy(urb->transfer_buffer, dst_buf, total_bytes_for_urb);
}
urb->dev = tascam->dev;
usb_get_urb(urb);
usb_anchor_urb(urb, &tascam->playback_anchor);
ret = usb_submit_urb(urb, GFP_ATOMIC);
if (ret < 0) {
dev_err_ratelimited(tascam->card->dev, "Failed to resubmit playback URB: %d\n", ret);
usb_unanchor_urb(urb);
usb_put_urb(urb);
}
out:
usb_put_urb(urb);
}
/**
* feedback_urb_complete() - Completion handler for feedback isochronous URBs.
* @urb: the completed URB
*
* This is the master clock for the driver. It runs in interrupt context.
* It reads the feedback value from the device, which indicates how many
* samples the device has consumed. This information is used to adjust the
* playback rate and to advance the capture stream pointer, keeping both
* streams in sync. It then calls snd_pcm_period_elapsed if necessary and
* resubmits itself.
*/
void feedback_urb_complete(struct urb *urb)
{
struct tascam_card *tascam = urb->context;
struct snd_pcm_substream *playback_ss, *capture_ss;
struct snd_pcm_runtime *playback_rt, *capture_rt;
unsigned long flags;
u64 total_frames_in_urb = 0;
int ret, p;
unsigned int old_in_idx, new_in_idx;
bool playback_period_elapsed = false;
bool capture_period_elapsed = false;
if (urb->status) {
if (urb->status != -ENOENT && urb->status != -ECONNRESET && urb->status != -ESHUTDOWN &&
urb->status != -ENODEV)
dev_err_ratelimited(tascam->card->dev, "Feedback URB failed: %d\n", urb->status);
goto out;
}
if (!tascam || !atomic_read(&tascam->playback_active))
goto out;
playback_ss = tascam->playback_substream;
if (!playback_ss || !playback_ss->runtime)
goto out;
playback_rt = playback_ss->runtime;
capture_ss = tascam->capture_substream;
capture_rt = capture_ss ? capture_ss->runtime : NULL;
spin_lock_irqsave(&tascam->lock, flags);
if (tascam->feedback_urb_skip_count > 0) {
tascam->feedback_urb_skip_count--;
goto unlock_and_continue;
}
old_in_idx = tascam->feedback_pattern_in_idx;
for (p = 0; p < urb->number_of_packets; p++) {
u8 feedback_value = 0;
const unsigned int *pattern;
bool packet_ok = (urb->iso_frame_desc[p].status == 0 &&
urb->iso_frame_desc[p].actual_length >= 1);
if (packet_ok)
feedback_value = *((u8 *)urb->transfer_buffer + urb->iso_frame_desc[p].offset);
if (packet_ok && feedback_value >= tascam->feedback_base_value &&
feedback_value <= tascam->feedback_max_value) {
pattern = tascam->feedback_patterns[feedback_value - tascam->feedback_base_value];
tascam->feedback_consecutive_errors = 0;
int i;
for (i = 0; i < 8; i++) {
unsigned int in_idx = (tascam->feedback_pattern_in_idx + i) % FEEDBACK_ACCUMULATOR_SIZE;
tascam->feedback_accumulator_pattern[in_idx] = pattern[i];
total_frames_in_urb += pattern[i];
}
} else {
unsigned int nominal_frames = playback_rt->rate / 8000;
int i;
if (tascam->feedback_synced) {
tascam->feedback_consecutive_errors++;
if (tascam->feedback_consecutive_errors > FEEDBACK_SYNC_LOSS_THRESHOLD) {
dev_err(tascam->card->dev, "Fatal: Feedback sync lost. Stopping stream.\n");
if (playback_ss)
snd_pcm_stop(playback_ss, SNDRV_PCM_STATE_XRUN);
if (capture_ss)
snd_pcm_stop(capture_ss, SNDRV_PCM_STATE_XRUN);
tascam->feedback_synced = false;
goto unlock_and_continue;
}
}
for (i = 0; i < 8; i++) {
unsigned int in_idx = (tascam->feedback_pattern_in_idx + i) % FEEDBACK_ACCUMULATOR_SIZE;
tascam->feedback_accumulator_pattern[in_idx] = nominal_frames;
total_frames_in_urb += nominal_frames;
}
}
tascam->feedback_pattern_in_idx = (tascam->feedback_pattern_in_idx + 8) % FEEDBACK_ACCUMULATOR_SIZE;
}
new_in_idx = tascam->feedback_pattern_in_idx;
if (!tascam->feedback_synced) {
unsigned int out_idx = tascam->feedback_pattern_out_idx;
bool is_ahead = (new_in_idx - out_idx) % FEEDBACK_ACCUMULATOR_SIZE < (FEEDBACK_ACCUMULATOR_SIZE / 2);
bool was_behind = (old_in_idx - out_idx) % FEEDBACK_ACCUMULATOR_SIZE >= (FEEDBACK_ACCUMULATOR_SIZE / 2);
if (is_ahead && was_behind) {
dev_dbg(tascam->card->dev, "Sync Acquired! (in: %u, out: %u)\n", new_in_idx, out_idx);
tascam->feedback_synced = true;
tascam->feedback_consecutive_errors = 0;
}
}
if (total_frames_in_urb > 0) {
tascam->playback_frames_consumed += total_frames_in_urb;
if (atomic_read(&tascam->capture_active))
tascam->capture_frames_processed += total_frames_in_urb;
}
if (playback_rt->period_size > 0) {
u64 current_period = div_u64(tascam->playback_frames_consumed, playback_rt->period_size);
if (current_period > tascam->last_period_pos) {
tascam->last_period_pos = current_period;
playback_period_elapsed = true;
}
}
if (atomic_read(&tascam->capture_active) && capture_rt && capture_rt->period_size > 0) {
u64 current_capture_period = div_u64(tascam->capture_frames_processed, capture_rt->period_size);
if (current_capture_period > tascam->last_capture_period_pos) {
tascam->last_capture_period_pos = current_capture_period;
capture_period_elapsed = true;
}
}
unlock_and_continue:
spin_unlock_irqrestore(&tascam->lock, flags);
if (playback_period_elapsed)
snd_pcm_period_elapsed(playback_ss);
if (capture_period_elapsed)
snd_pcm_period_elapsed(capture_ss);
urb->dev = tascam->dev;
usb_get_urb(urb);
usb_anchor_urb(urb, &tascam->feedback_anchor);
ret = usb_submit_urb(urb, GFP_ATOMIC);
if (ret < 0) {
dev_err_ratelimited(tascam->card->dev, "Failed to resubmit feedback URB: %d\n", ret);
usb_unanchor_urb(urb);
usb_put_urb(urb);
}
out:
usb_put_urb(urb);
}