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us144mkii
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This commit is contained in:
Šerif Rami 2025-08-09 14:12:48 +02:00
parent c8eb8e1adf
commit 9862f9da7f
6 changed files with 926 additions and 47 deletions
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162
us144mkii.c
View File

@ -35,6 +35,100 @@ static void tascam_disconnect(struct usb_interface *intf);
static int tascam_suspend(struct usb_interface *intf, pm_message_t message);
static int tascam_resume(struct usb_interface *intf);
void tascam_free_urbs(struct tascam_card *tascam) {
int i;
usb_kill_anchored_urbs(&tascam->playback_anchor);
for (i = 0; i < NUM_PLAYBACK_URBS; i++) {
if (tascam->playback_urbs[i]) {
usb_free_coherent(tascam->dev, tascam->playback_urb_alloc_size,
tascam->playback_urbs[i]->transfer_buffer,
tascam->playback_urbs[i]->transfer_dma);
usb_free_urb(tascam->playback_urbs[i]);
tascam->playback_urbs[i] = NULL;
}
}
usb_kill_anchored_urbs(&tascam->feedback_anchor);
for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
if (tascam->feedback_urbs[i]) {
usb_free_coherent(tascam->dev, tascam->feedback_urb_alloc_size,
tascam->feedback_urbs[i]->transfer_buffer,
tascam->feedback_urbs[i]->transfer_dma);
usb_free_urb(tascam->feedback_urbs[i]);
tascam->feedback_urbs[i] = NULL;
}
}
}
int tascam_alloc_urbs(struct tascam_card *tascam) {
int i;
size_t max_packet_size;
max_packet_size = ((96000 / 8000) + 2) * BYTES_PER_FRAME;
tascam->playback_urb_alloc_size = max_packet_size * PLAYBACK_URB_PACKETS;
for (i = 0; i < NUM_PLAYBACK_URBS; i++) {
struct urb *urb = usb_alloc_urb(PLAYBACK_URB_PACKETS, GFP_KERNEL);
if (!urb)
goto error;
tascam->playback_urbs[i] = urb;
urb->transfer_buffer =
usb_alloc_coherent(tascam->dev, tascam->playback_urb_alloc_size,
GFP_KERNEL, &urb->transfer_dma);
if (!urb->transfer_buffer)
goto error;
urb->dev = tascam->dev;
urb->pipe = usb_sndisocpipe(tascam->dev, EP_AUDIO_OUT);
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
urb->interval = 1;
urb->context = tascam;
urb->complete = playback_urb_complete;
}
tascam->feedback_urb_alloc_size = FEEDBACK_PACKET_SIZE * FEEDBACK_URB_PACKETS;
for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
struct urb *f_urb = usb_alloc_urb(FEEDBACK_URB_PACKETS, GFP_KERNEL);
if (!f_urb)
goto error;
tascam->feedback_urbs[i] = f_urb;
f_urb->transfer_buffer =
usb_alloc_coherent(tascam->dev, tascam->feedback_urb_alloc_size,
GFP_KERNEL, &f_urb->transfer_dma);
if (!f_urb->transfer_buffer)
goto error;
f_urb->dev = tascam->dev;
f_urb->pipe = usb_rcvisocpipe(tascam->dev, EP_PLAYBACK_FEEDBACK);
f_urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
f_urb->interval = 4;
f_urb->context = tascam;
f_urb->complete = feedback_urb_complete;
}
return 0;
error:
dev_err(tascam->card->dev, "Failed to allocate URBs\n");
tascam_free_urbs(tascam);
return -ENOMEM;
}
void tascam_stop_work_handler(struct work_struct *work) {
struct tascam_card *tascam =
container_of(work, struct tascam_card, stop_work);
usb_kill_anchored_urbs(&tascam->playback_anchor);
usb_kill_anchored_urbs(&tascam->feedback_anchor);
atomic_set(&tascam->active_urbs, 0);
}
/**
* tascam_card_private_free() - Frees private data associated with the sound
* card.
@ -63,6 +157,7 @@ static void tascam_card_private_free(struct snd_card *card) {
* - Performing a vendor-specific handshake with the device.
* - Setting alternate settings for USB interfaces.
* - Creating and registering the ALSA sound card and PCM device.
* - Allocating and initializing URBs for audio transfers.
*
* Return: 0 on success, or a negative error code on failure.
*/
@ -144,6 +239,11 @@ static int tascam_probe(struct usb_interface *intf,
tascam->iface0 = intf;
spin_lock_init(&tascam->lock);
init_usb_anchor(&tascam->playback_anchor);
init_usb_anchor(&tascam->feedback_anchor);
INIT_WORK(&tascam->stop_work, tascam_stop_work_handler);
INIT_WORK(&tascam->stop_pcm_work, tascam_stop_pcm_work_handler);
err = snd_pcm_new(card, "US144MKII PCM", 0, 1, 1, &tascam->pcm);
if (err < 0)
@ -155,6 +255,10 @@ static int tascam_probe(struct usb_interface *intf,
if (err < 0)
goto free_card;
err = tascam_alloc_urbs(tascam);
if (err < 0)
goto free_card;
strscpy(card->driver, DRIVER_NAME, sizeof(card->driver));
if (dev->descriptor.idProduct == USB_PID_TASCAM_US144) {
strscpy(card->shortname, "TASCAM US-144", sizeof(card->shortname));
@ -177,6 +281,7 @@ static int tascam_probe(struct usb_interface *intf,
return 0;
free_card:
tascam_free_urbs(tascam);
snd_card_free(card);
return err;
}
@ -186,7 +291,8 @@ free_card:
* @intf: The USB interface being disconnected.
*
* This function is called when the device is disconnected from the system.
* It cleans up all allocated resources by freeing the sound card.
* It cleans up all allocated resources by freeing the sound card, which in
* turn triggers freeing of URBs and other resources.
*/
static void tascam_disconnect(struct usb_interface *intf) {
struct tascam_card *tascam = usb_get_intfdata(intf);
@ -196,6 +302,9 @@ static void tascam_disconnect(struct usb_interface *intf) {
if (intf->cur_altsetting->desc.bInterfaceNumber == 0) {
snd_card_disconnect(tascam->card);
cancel_work_sync(&tascam->stop_work);
cancel_work_sync(&tascam->stop_pcm_work);
tascam_free_urbs(tascam);
snd_card_free(tascam->card);
dev_idx--;
}
@ -206,11 +315,24 @@ static void tascam_disconnect(struct usb_interface *intf) {
* @intf: The USB interface being suspended.
* @message: Power management message.
*
* This function is a stub for handling device suspension.
* This function is called when the device is suspended. It stops all active
* streams and kills all URBs.
*
* Return: 0 on success.
*/
static int tascam_suspend(struct usb_interface *intf, pm_message_t message) {
struct tascam_card *tascam = usb_get_intfdata(intf);
if (!tascam)
return 0;
snd_pcm_suspend_all(tascam->pcm);
cancel_work_sync(&tascam->stop_work);
cancel_work_sync(&tascam->stop_pcm_work);
usb_kill_anchored_urbs(&tascam->playback_anchor);
usb_kill_anchored_urbs(&tascam->feedback_anchor);
return 0;
}
@ -218,11 +340,41 @@ static int tascam_suspend(struct usb_interface *intf, pm_message_t message) {
* tascam_resume() - Handles device resumption from suspend.
* @intf: The USB interface being resumed.
*
* This function is a stub for handling device resumption.
* This function is called when the device resumes from suspend. It
* re-establishes the active USB interface settings and re-configures the sample
* rate if it was previously active.
*
* Return: 0 on success.
* Return: 0 on success, or a negative error code on failure.
*/
static int tascam_resume(struct usb_interface *intf) { return 0; }
static int tascam_resume(struct usb_interface *intf) {
struct tascam_card *tascam = usb_get_intfdata(intf);
int err;
if (!tascam)
return 0;
dev_info(&intf->dev, "resuming TASCAM US-144MKII\n");
/* Re-establish the active USB interface settings. */
err = usb_set_interface(tascam->dev, 0, 1);
if (err < 0) {
dev_err(&intf->dev, "resume: failed to set alt setting on intf 0: %d\n",
err);
return err;
}
err = usb_set_interface(tascam->dev, 1, 1);
if (err < 0) {
dev_err(&intf->dev, "resume: failed to set alt setting on intf 1: %d\n",
err);
return err;
}
/* Re-configure the sample rate if one was previously active */
if (tascam->current_rate > 0)
us144mkii_configure_device_for_rate(tascam, tascam->current_rate);
return 0;
}
static const struct usb_device_id tascam_usb_ids[] = {
{USB_DEVICE(USB_VID_TASCAM, USB_PID_TASCAM_US144)},

188
us144mkii.h
View File

@ -5,6 +5,7 @@
#define __US144MKII_H
#include <linux/usb.h>
#include <linux/workqueue.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
@ -16,21 +17,87 @@
#define USB_PID_TASCAM_US144 0x800f
#define USB_PID_TASCAM_US144MKII 0x8020
/* --- USB Endpoints (Alternate Setting 1) --- */
#define EP_PLAYBACK_FEEDBACK 0x81
#define EP_AUDIO_OUT 0x02
/* --- USB Control Message Protocol --- */
#define RT_H2D_CLASS_EP (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT)
#define RT_D2H_VENDOR_DEV (USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE)
#define RT_H2D_VENDOR_DEV (USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE)
enum uac_request {
UAC_SET_CUR = 0x01,
};
enum uac_control_selector {
UAC_SAMPLING_FREQ_CONTROL = 0x0100,
};
enum tascam_vendor_request {
VENDOR_REQ_REGISTER_WRITE = 0x41,
VENDOR_REQ_MODE_CONTROL = 0x49,
};
enum tascam_mode_value {
MODE_VAL_HANDSHAKE_READ = 0x0000,
MODE_VAL_CONFIG = 0x0010,
MODE_VAL_STREAM_START = 0x0030,
};
enum tascam_register {
REG_ADDR_UNKNOWN_0D = 0x0d04,
REG_ADDR_UNKNOWN_0E = 0x0e00,
REG_ADDR_UNKNOWN_0F = 0x0f00,
REG_ADDR_RATE_44100 = 0x1000,
REG_ADDR_RATE_48000 = 0x1002,
REG_ADDR_RATE_88200 = 0x1008,
REG_ADDR_RATE_96000 = 0x100a,
REG_ADDR_UNKNOWN_11 = 0x110b,
};
#define REG_VAL_ENABLE 0x0101
/* --- URB Configuration --- */
#define NUM_PLAYBACK_URBS 4
#define PLAYBACK_URB_PACKETS 8
#define NUM_FEEDBACK_URBS 4
#define FEEDBACK_URB_PACKETS 1
#define FEEDBACK_PACKET_SIZE 3
#define USB_CTRL_TIMEOUT_MS 1000
#define FEEDBACK_SYNC_LOSS_THRESHOLD 41
/* --- Audio Format Configuration --- */
#define BYTES_PER_SAMPLE 3
#define NUM_CHANNELS 4
#define BYTES_PER_FRAME (NUM_CHANNELS * BYTES_PER_SAMPLE)
/* --- USB Control Message Protocol --- */
#define RT_D2H_VENDOR_DEV (USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE)
#define VENDOR_REQ_MODE_CONTROL 0x49
#define MODE_VAL_HANDSHAKE_READ 0x0000
#define USB_CTRL_TIMEOUT_MS 1000
#define FEEDBACK_ACCUMULATOR_SIZE 128
struct tascam_card;
#include "us144mkii_pcm.h"
/**
* struct us144mkii_frame_pattern_observer - State for dynamic feedback
* patterns.
* @sample_rate_khz: The current sample rate in kHz.
* @base_feedback_value: The nominal feedback value for the current rate.
* @feedback_offset: An offset to align the feedback value range.
* @full_frame_patterns: A 2D array of pre-calculated packet size patterns.
* @current_index: The current index into the pattern array.
* @previous_index: The previous index, used for state tracking.
* @sync_locked: A flag indicating if the pattern has locked to the stream.
*/
struct us144mkii_frame_pattern_observer {
unsigned int sample_rate_khz;
unsigned int base_feedback_value;
int feedback_offset;
unsigned int full_frame_patterns[5][8];
unsigned int current_index;
unsigned int previous_index;
bool sync_locked;
};
/**
* struct tascam_card - Main driver data structure for the TASCAM US-144MKII.
* @dev: Pointer to the USB device.
@ -38,38 +105,121 @@ struct tascam_card;
* @iface1: Pointer to USB interface 1 (MIDI).
* @card: Pointer to the ALSA sound card instance.
* @pcm: Pointer to the ALSA PCM device.
*
* @playback_substream: Pointer to the active playback PCM substream.
* @capture_substream: Pointer to the active capture PCM substream.
* @playback_urbs: Array of URBs for playback.
* @playback_urb_alloc_size: Size of allocated buffer for each playback URB.
* @feedback_urbs: Array of URBs for feedback.
* @feedback_urb_alloc_size: Size of allocated buffer for each feedback URB.
* @playback_active: Atomic flag indicating if playback is active.
* @capture_active: Atomic flag indicating if capture is active.
* @driver_playback_pos: Current position in the ALSA playback buffer (frames).
* @driver_capture_pos: Current position in the ALSA capture buffer (frames).
* @playback_frames_consumed: Total frames consumed by playback.
* @driver_playback_pos: Current position in the ALSA playback buffer (frames).
* @last_period_pos: Last reported period position for playback.
*
* @capture_substream: Pointer to the active capture PCM substream.
* @capture_active: Atomic flag indicating if capture is active.
* @driver_capture_pos: Current position in the ALSA capture buffer (frames).
* @capture_frames_processed: Total frames processed for capture.
* @current_rate: Currently configured sample rate of the device.
* @last_capture_period_pos: Last reported period position for capture.
*
* @stop_work: Work struct for deferred stream stopping.
* @stop_pcm_work: Work struct for stopping PCM due to a fatal error (e.g.
* xrun).
*
* @lock: Main spinlock for protecting shared driver state.
* @active_urbs: Atomic counter for active URBs.
* @current_rate: Currently configured sample rate of the device.
*
* @feedback_accumulator_pattern: Stores the calculated frames per packet for
* feedback.
* @feedback_pattern_out_idx: Read index for feedback_accumulator_pattern.
* @feedback_pattern_in_idx: Write index for feedback_accumulator_pattern.
* @feedback_synced: Flag indicating if feedback is synced.
* @feedback_consecutive_errors: Counter for consecutive feedback errors.
* @feedback_urb_skip_count: Number of feedback URBs to skip initially for
* stabilization.
* @fpo: Holds the state for the dynamic feedback pattern generation.
*
* @playback_anchor: USB anchor for playback URBs.
* @feedback_anchor: USB anchor for feedback URBs.
*/
struct tascam_card {
/* --- Core device pointers --- */
struct usb_device *dev;
struct usb_interface *iface0;
struct usb_interface *iface1;
struct snd_card *card;
struct snd_pcm *pcm;
/* --- PCM Substreams --- */
struct snd_pcm_substream *playback_substream;
struct snd_pcm_substream *capture_substream;
/* --- URBs and Anchors --- */
struct urb *playback_urbs[NUM_PLAYBACK_URBS];
size_t playback_urb_alloc_size;
struct urb *feedback_urbs[NUM_FEEDBACK_URBS];
size_t feedback_urb_alloc_size;
struct usb_anchor playback_anchor;
struct usb_anchor feedback_anchor;
/* --- Stream State --- */
spinlock_t lock;
atomic_t playback_active;
atomic_t capture_active;
snd_pcm_uframes_t driver_playback_pos;
snd_pcm_uframes_t driver_capture_pos;
u64 playback_frames_consumed;
u64 capture_frames_processed;
atomic_t active_urbs;
int current_rate;
spinlock_t lock;
/* --- Playback State --- */
u64 playback_frames_consumed;
snd_pcm_uframes_t driver_playback_pos;
u64 last_period_pos;
/* --- Capture State --- */
u64 capture_frames_processed;
snd_pcm_uframes_t driver_capture_pos;
u64 last_capture_period_pos;
/* --- Feedback Sync State --- */
unsigned int feedback_accumulator_pattern[FEEDBACK_ACCUMULATOR_SIZE];
unsigned int feedback_pattern_out_idx;
unsigned int feedback_pattern_in_idx;
bool feedback_synced;
unsigned int feedback_consecutive_errors;
unsigned int feedback_urb_skip_count;
struct us144mkii_frame_pattern_observer fpo;
/* --- Workqueues --- */
struct work_struct stop_work;
struct work_struct stop_pcm_work;
};
/**
* tascam_free_urbs() - Free all allocated URBs and associated buffers.
* @tascam: the tascam_card instance
*
* This function kills, unlinks, and frees all playback and feedback URBs,
* along with their transfer buffers.
*/
void tascam_free_urbs(struct tascam_card *tascam);
/**
* tascam_alloc_urbs() - Allocate all URBs and associated buffers.
* @tascam: the tascam_card instance
*
* This function allocates and initializes all URBs for playback and feedback.
*
* Return: 0 on success, or a negative error code on failure.
*/
int tascam_alloc_urbs(struct tascam_card *tascam);
/**
* tascam_stop_work_handler() - Work handler to stop all active streams.
* @work: Pointer to the work_struct.
*
* This function is scheduled to stop all active URBs (playback, feedback)
* and reset the active_urbs counter.
*/
void tascam_stop_work_handler(struct work_struct *work);
#endif /* __US144MKII_H */

1
us144mkii_capture.c
View File

@ -52,6 +52,7 @@ static int tascam_capture_prepare(struct snd_pcm_substream *substream) {
tascam->driver_capture_pos = 0;
tascam->capture_frames_processed = 0;
tascam->last_capture_period_pos = 0;
return 0;
}

207
us144mkii_pcm.c
View File

@ -3,6 +3,36 @@
#include "us144mkii.h"
/**
* fpoInitPattern() - Generates a packet distribution pattern.
* @size: The number of elements in the pattern array (e.g., 8).
* @pattern_array: Pointer to the array to be populated.
* @initial_value: The base value to initialize each element with.
* @target_sum: The desired sum of all elements in the final array.
*
* This function initializes an array with a base value and then iteratively
* adjusts the elements to match a target sum, distributing the difference
* as evenly as possible.
*/
static void fpoInitPattern(unsigned int size, unsigned int *pattern_array,
unsigned int initial_value, int target_sum) {
int diff, i;
if (!size)
return;
for (i = 0; i < size; ++i)
pattern_array[i] = initial_value;
diff = target_sum - (size * initial_value);
for (i = 0; i < abs(diff); ++i) {
if (diff > 0)
pattern_array[i]++;
else
pattern_array[i]--;
}
}
const struct snd_pcm_hardware tascam_pcm_hw = {
.info = (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP_VALID |
@ -21,8 +51,137 @@ const struct snd_pcm_hardware tascam_pcm_hw = {
.periods_max = 1024,
};
void process_playback_routing_us144mkii(struct tascam_card *tascam,
const u8 *src_buffer, u8 *dst_buffer,
size_t frames) {
/* This is a stub. Routing will be added in a later commit. */
if (src_buffer != dst_buffer)
memcpy(dst_buffer, src_buffer, frames * BYTES_PER_FRAME);
}
int us144mkii_configure_device_for_rate(struct tascam_card *tascam, int rate) {
struct usb_device *dev = tascam->dev;
u8 *rate_payload_buf;
u16 rate_vendor_wValue;
int err = 0;
const u8 *current_payload_src;
static const u8 payload_44100[] = {0x44, 0xac, 0x00};
static const u8 payload_48000[] = {0x80, 0xbb, 0x00};
static const u8 payload_88200[] = {0x88, 0x58, 0x01};
static const u8 payload_96000[] = {0x00, 0x77, 0x01};
switch (rate) {
case 44100:
current_payload_src = payload_44100;
rate_vendor_wValue = REG_ADDR_RATE_44100;
break;
case 48000:
current_payload_src = payload_48000;
rate_vendor_wValue = REG_ADDR_RATE_48000;
break;
case 88200:
current_payload_src = payload_88200;
rate_vendor_wValue = REG_ADDR_RATE_88200;
break;
case 96000:
current_payload_src = payload_96000;
rate_vendor_wValue = REG_ADDR_RATE_96000;
break;
default:
dev_err(&dev->dev, "Unsupported sample rate %d for configuration\n", rate);
return -EINVAL;
}
rate_payload_buf = kmemdup(current_payload_src, 3, GFP_KERNEL);
if (!rate_payload_buf)
return -ENOMEM;
dev_info(&dev->dev, "Configuring device for %d Hz\n", rate);
err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), VENDOR_REQ_MODE_CONTROL,
RT_H2D_VENDOR_DEV, MODE_VAL_CONFIG, 0x0000, NULL, 0,
USB_CTRL_TIMEOUT_MS);
if (err < 0)
goto fail;
err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
RT_H2D_CLASS_EP, UAC_SAMPLING_FREQ_CONTROL,
EP_AUDIO_OUT, rate_payload_buf, 3, USB_CTRL_TIMEOUT_MS);
if (err < 0)
goto fail;
err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), VENDOR_REQ_REGISTER_WRITE,
RT_H2D_VENDOR_DEV, REG_ADDR_UNKNOWN_0D, REG_VAL_ENABLE,
NULL, 0, USB_CTRL_TIMEOUT_MS);
if (err < 0)
goto fail;
err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), VENDOR_REQ_REGISTER_WRITE,
RT_H2D_VENDOR_DEV, REG_ADDR_UNKNOWN_0E, REG_VAL_ENABLE,
NULL, 0, USB_CTRL_TIMEOUT_MS);
if (err < 0)
goto fail;
err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), VENDOR_REQ_REGISTER_WRITE,
RT_H2D_VENDOR_DEV, REG_ADDR_UNKNOWN_0F, REG_VAL_ENABLE,
NULL, 0, USB_CTRL_TIMEOUT_MS);
if (err < 0)
goto fail;
err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), VENDOR_REQ_REGISTER_WRITE,
RT_H2D_VENDOR_DEV, rate_vendor_wValue, REG_VAL_ENABLE,
NULL, 0, USB_CTRL_TIMEOUT_MS);
if (err < 0)
goto fail;
err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), VENDOR_REQ_REGISTER_WRITE,
RT_H2D_VENDOR_DEV, REG_ADDR_UNKNOWN_11, REG_VAL_ENABLE,
NULL, 0, USB_CTRL_TIMEOUT_MS);
if (err < 0)
goto fail;
err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), VENDOR_REQ_MODE_CONTROL,
RT_H2D_VENDOR_DEV, MODE_VAL_STREAM_START, 0x0000, NULL,
0, USB_CTRL_TIMEOUT_MS);
if (err < 0)
goto fail;
kfree(rate_payload_buf);
return 0;
fail:
dev_err(&dev->dev, "Device configuration failed at rate %d with error %d\n",
rate, err);
kfree(rate_payload_buf);
return err;
}
int tascam_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
int err;
unsigned int rate = params_rate(params);
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
tascam->fpo.sample_rate_khz = rate / 1000;
tascam->fpo.base_feedback_value = tascam->fpo.sample_rate_khz;
tascam->fpo.feedback_offset = 2;
tascam->fpo.current_index = 0;
tascam->fpo.previous_index = 0;
tascam->fpo.sync_locked = false;
unsigned int initial_value = tascam->fpo.sample_rate_khz / 8;
for (int i = 0; i < 5; i++) {
int target_sum =
tascam->fpo.sample_rate_khz - tascam->fpo.feedback_offset + i;
fpoInitPattern(8, tascam->fpo.full_frame_patterns[i], initial_value,
target_sum);
}
}
if (tascam->current_rate != rate) {
err = us144mkii_configure_device_for_rate(tascam, rate);
if (err < 0) {
tascam->current_rate = 0;
return err;
}
tascam->current_rate = rate;
}
return 0;
}
@ -31,7 +190,11 @@ int tascam_pcm_hw_free(struct snd_pcm_substream *substream) { return 0; }
int tascam_pcm_trigger(struct snd_pcm_substream *substream, int cmd) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
int err = 0;
int i;
bool do_start = false;
bool do_stop = false;
{
guard(spinlock_irqsave)(&tascam->lock);
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
@ -39,6 +202,7 @@ int tascam_pcm_trigger(struct snd_pcm_substream *substream, int cmd) {
if (!atomic_read(&tascam->playback_active)) {
atomic_set(&tascam->playback_active, 1);
atomic_set(&tascam->capture_active, 1);
do_start = true;
}
break;
case SNDRV_PCM_TRIGGER_STOP:
@ -47,12 +211,55 @@ int tascam_pcm_trigger(struct snd_pcm_substream *substream, int cmd) {
if (atomic_read(&tascam->playback_active)) {
atomic_set(&tascam->playback_active, 0);
atomic_set(&tascam->capture_active, 0);
do_stop = true;
}
break;
default:
err = -EINVAL;
break;
}
}
if (do_start) {
if (atomic_read(&tascam->active_urbs) > 0) {
dev_WARN(tascam->card->dev, "Cannot start, URBs still active.\n");
return -EAGAIN;
}
for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
usb_get_urb(tascam->feedback_urbs[i]);
usb_anchor_urb(tascam->feedback_urbs[i], &tascam->feedback_anchor);
err = usb_submit_urb(tascam->feedback_urbs[i], GFP_ATOMIC);
if (err < 0) {
usb_unanchor_urb(tascam->feedback_urbs[i]);
usb_put_urb(tascam->feedback_urbs[i]);
atomic_dec(&tascam->active_urbs);
goto start_rollback;
}
atomic_inc(&tascam->active_urbs);
}
for (i = 0; i < NUM_PLAYBACK_URBS; i++) {
usb_get_urb(tascam->playback_urbs[i]);
usb_anchor_urb(tascam->playback_urbs[i], &tascam->playback_anchor);
err = usb_submit_urb(tascam->playback_urbs[i], GFP_ATOMIC);
if (err < 0) {
usb_unanchor_urb(tascam->playback_urbs[i]);
usb_put_urb(tascam->playback_urbs[i]);
atomic_dec(&tascam->active_urbs);
goto start_rollback;
}
atomic_inc(&tascam->active_urbs);
}
return 0;
start_rollback:
dev_err(tascam->card->dev, "Failed to submit URBs to start stream: %d\n",
err);
do_stop = true;
}
if (do_stop)
schedule_work(&tascam->stop_work);
return err;
}

64
us144mkii_pcm.h
View File

@ -28,6 +28,38 @@ extern const struct snd_pcm_ops tascam_playback_ops;
*/
extern const struct snd_pcm_ops tascam_capture_ops;
/**
* 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, and resubmits the URB.
*/
void playback_urb_complete(struct 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);
/**
* tascam_stop_pcm_work_handler() - Work handler to stop PCM streams.
* @work: Pointer to the work_struct.
*
* This function is scheduled to stop PCM streams (playback and capture)
* from a workqueue context, avoiding blocking operations in interrupt context.
*/
void tascam_stop_pcm_work_handler(struct work_struct *work);
/**
* tascam_init_pcm() - Initializes the ALSA PCM device.
* @pcm: Pointer to the ALSA PCM device to initialize.
@ -39,14 +71,40 @@ extern const struct snd_pcm_ops tascam_capture_ops;
*/
int tascam_init_pcm(struct snd_pcm *pcm);
/**
* us144mkii_configure_device_for_rate() - Set sample rate via USB control msgs
* @tascam: the tascam_card instance
* @rate: the target sample rate (e.g., 44100, 96000)
*
* This function sends a sequence of vendor-specific and UAC control messages
* to configure the device hardware for the specified sample rate.
*
* Return: 0 on success, or a negative error code on failure.
*/
int us144mkii_configure_device_for_rate(struct tascam_card *tascam, int rate);
/**
* 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);
/**
* tascam_pcm_hw_params() - Configures hardware parameters for PCM streams.
* @substream: The ALSA PCM substream.
* @params: The hardware parameters to apply.
*
* This function is a stub for handling hardware parameter configuration.
* This function allocates pages for the PCM buffer and, for playback streams,
* selects the appropriate feedback patterns based on the requested sample rate.
* It also configures the device hardware for the selected sample rate if it
* has changed.
*
* Return: 0 on success.
* Return: 0 on success, or a negative error code on failure.
*/
int tascam_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params);
@ -67,7 +125,7 @@ int tascam_pcm_hw_free(struct snd_pcm_substream *substream);
* @cmd: The trigger command (e.g., SNDRV_PCM_TRIGGER_START).
*
* This function handles starting and stopping of playback and capture streams
* by setting atomic flags.
* by submitting or killing the associated URBs.
*
* Return: 0 on success, or a negative error code on failure.
*/

313
us144mkii_playback.c
View File

@ -43,15 +43,58 @@ static int tascam_playback_close(struct snd_pcm_substream *substream) {
* tascam_playback_prepare() - Prepares the PCM playback substream for use.
* @substream: The ALSA PCM substream to prepare.
*
* This function initializes playback-related counters.
* This function initializes playback-related counters and flags, and configures
* the playback URBs with appropriate packet sizes based on the nominal frame
* rate.
*
* Return: 0 on success.
*/
static int tascam_playback_prepare(struct snd_pcm_substream *substream) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
int i, u;
size_t nominal_frames_per_packet, nominal_bytes_per_packet;
size_t total_bytes_in_urb;
tascam->driver_playback_pos = 0;
tascam->playback_frames_consumed = 0;
tascam->last_period_pos = 0;
tascam->feedback_pattern_in_idx = 0;
tascam->feedback_pattern_out_idx = 0;
tascam->feedback_synced = false;
tascam->feedback_consecutive_errors = 0;
tascam->feedback_urb_skip_count = NUM_FEEDBACK_URBS;
nominal_frames_per_packet = runtime->rate / 8000;
for (i = 0; i < FEEDBACK_ACCUMULATOR_SIZE; i++)
tascam->feedback_accumulator_pattern[i] = nominal_frames_per_packet;
for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
struct urb *f_urb = tascam->feedback_urbs[i];
int j;
f_urb->number_of_packets = FEEDBACK_URB_PACKETS;
f_urb->transfer_buffer_length = FEEDBACK_URB_PACKETS * FEEDBACK_PACKET_SIZE;
for (j = 0; j < FEEDBACK_URB_PACKETS; j++) {
f_urb->iso_frame_desc[j].offset = j * FEEDBACK_PACKET_SIZE;
f_urb->iso_frame_desc[j].length = FEEDBACK_PACKET_SIZE;
}
}
nominal_bytes_per_packet = nominal_frames_per_packet * BYTES_PER_FRAME;
total_bytes_in_urb = nominal_bytes_per_packet * PLAYBACK_URB_PACKETS;
for (u = 0; u < NUM_PLAYBACK_URBS; u++) {
struct urb *urb = tascam->playback_urbs[u];
memset(urb->transfer_buffer, 0, tascam->playback_urb_alloc_size);
urb->transfer_buffer_length = total_bytes_in_urb;
urb->number_of_packets = PLAYBACK_URB_PACKETS;
for (i = 0; i < PLAYBACK_URB_PACKETS; i++) {
urb->iso_frame_desc[i].offset = i * nominal_bytes_per_packet;
urb->iso_frame_desc[i].length = nominal_bytes_per_packet;
}
}
return 0;
}
@ -101,3 +144,271 @@ const struct snd_pcm_ops tascam_playback_ops = {
.trigger = tascam_pcm_trigger,
.pointer = tascam_playback_pointer,
};
void playback_urb_complete(struct urb *urb) {
struct tascam_card *tascam = urb->context;
struct snd_pcm_substream *substream;
struct snd_pcm_runtime *runtime;
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;
{
guard(spinlock_irqsave)(&tascam->lock);
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;
}
if (total_bytes_for_urb > 0) {
u8 *dst_buf = urb->transfer_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,
runtime->dma_area + frames_to_bytes(runtime, offset_frames),
first_chunk_bytes);
memcpy(dst_buf + first_chunk_bytes, runtime->dma_area,
second_chunk_bytes);
} else {
memcpy(dst_buf,
runtime->dma_area + frames_to_bytes(runtime, offset_frames),
total_bytes_for_urb);
}
process_playback_routing_us144mkii(tascam, dst_buf, dst_buf,
frames_to_copy);
}
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);
atomic_dec(&tascam->active_urbs); /* Decrement on failed resubmission */
}
out:
usb_put_urb(urb);
}
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;
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);
atomic_dec(&tascam->active_urbs); /* Decrement on failed resubmission */
}
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;
{
guard(spinlock_irqsave)(&tascam->lock);
if (tascam->feedback_urb_skip_count > 0) {
tascam->feedback_urb_skip_count--;
goto continue_unlock;
}
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) {
int delta = feedback_value - tascam->fpo.base_feedback_value +
tascam->fpo.feedback_offset;
int pattern_idx;
if (delta < 0) {
pattern_idx = 0; // Clamp to the lowest pattern
} else if (delta >= 5) {
pattern_idx = 4; // Clamp to the highest pattern
} else {
pattern_idx = delta;
}
pattern = tascam->fpo.full_frame_patterns[pattern_idx];
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");
schedule_work(&tascam->stop_pcm_work);
tascam->feedback_synced = false;
goto continue_unlock;
}
}
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;
}
}
}
continue_unlock:
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);
}
void tascam_stop_pcm_work_handler(struct work_struct *work) {
struct tascam_card *tascam =
container_of(work, struct tascam_card, stop_pcm_work);
if (tascam->playback_substream)
snd_pcm_stop(tascam->playback_substream, SNDRV_PCM_STATE_XRUN);
if (tascam->capture_substream)
snd_pcm_stop(tascam->capture_substream, SNDRV_PCM_STATE_XRUN);
}