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This commit is contained in:
Šerif Rami 2025-08-09 13:55:57 +02:00
parent 6874a98cf4
commit 7fd61770fc
8 changed files with 35 additions and 2919 deletions
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441
us144mkii.c
View File

@ -29,369 +29,27 @@ static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
static bool enable[SNDRV_CARDS] = {1, [1 ...(SNDRV_CARDS - 1)] = 0};
static int dev_idx;
static struct usb_driver tascam_alsa_driver;
/* --- Forward Declarations --- */
static int tascam_probe(struct usb_interface *intf,
const struct usb_device_id *usb_id);
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);
/**
* driver_version_show() - Sysfs attribute to display the driver version.
* @dev: Pointer to the device structure.
* @attr: Pointer to the device attribute structure.
* @buf: Buffer to write the version string into.
*
* This function is a sysfs callback that provides the current driver version
* string to user-space when the 'driver_version' attribute is read.
*
* Return: The number of bytes written to the buffer.
*/
static ssize_t driver_version_show(struct device *dev,
struct device_attribute *attr, char *buf) {
return sysfs_emit(buf, "%s\n", DRIVER_VERSION);
}
static DEVICE_ATTR_RO(driver_version);
/**
* tascam_free_urbs() - Free all allocated URBs and associated buffers.
* @tascam: the tascam_card instance
*
* This function kills, unlinks, and frees all playback, feedback,
* capture, and MIDI URBs, along with their transfer buffers and the
* capture ring/decode buffers.
*/
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;
}
}
usb_kill_anchored_urbs(&tascam->capture_anchor);
for (i = 0; i < NUM_CAPTURE_URBS; i++) {
if (tascam->capture_urbs[i]) {
usb_free_coherent(tascam->dev, tascam->capture_urb_alloc_size,
tascam->capture_urbs[i]->transfer_buffer,
tascam->capture_urbs[i]->transfer_dma);
usb_free_urb(tascam->capture_urbs[i]);
tascam->capture_urbs[i] = NULL;
}
}
usb_kill_anchored_urbs(&tascam->midi_in_anchor);
for (i = 0; i < NUM_MIDI_IN_URBS; i++) {
if (tascam->midi_in_urbs[i]) {
usb_free_coherent(tascam->dev, MIDI_IN_BUF_SIZE,
tascam->midi_in_urbs[i]->transfer_buffer,
tascam->midi_in_urbs[i]->transfer_dma);
usb_free_urb(tascam->midi_in_urbs[i]);
tascam->midi_in_urbs[i] = NULL;
}
}
usb_kill_anchored_urbs(&tascam->midi_out_anchor);
for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
if (tascam->midi_out_urbs[i]) {
usb_free_coherent(tascam->dev, MIDI_OUT_BUF_SIZE,
tascam->midi_out_urbs[i]->transfer_buffer,
tascam->midi_out_urbs[i]->transfer_dma);
usb_free_urb(tascam->midi_out_urbs[i]);
tascam->midi_out_urbs[i] = NULL;
}
}
kfree(tascam->capture_routing_buffer);
tascam->capture_routing_buffer = NULL;
kfree(tascam->capture_decode_dst_block);
tascam->capture_decode_dst_block = NULL;
kfree(tascam->capture_decode_raw_block);
tascam->capture_decode_raw_block = NULL;
kfree(tascam->capture_ring_buffer);
tascam->capture_ring_buffer = NULL;
}
/**
* tascam_alloc_urbs() - Allocate all URBs and associated buffers.
* @tascam: the tascam_card instance
*
* This function allocates and initializes all URBs for playback, feedback,
* capture, and MIDI, as well as the necessary buffers for data processing.
*
* Return: 0 on success, or a negative error code on failure.
*/
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;
}
tascam->capture_urb_alloc_size = CAPTURE_URB_SIZE;
for (i = 0; i < NUM_CAPTURE_URBS; i++) {
struct urb *c_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!c_urb)
goto error;
tascam->capture_urbs[i] = c_urb;
c_urb->transfer_buffer =
usb_alloc_coherent(tascam->dev, tascam->capture_urb_alloc_size,
GFP_KERNEL, &c_urb->transfer_dma);
if (!c_urb->transfer_buffer)
goto error;
usb_fill_bulk_urb(c_urb, tascam->dev,
usb_rcvbulkpipe(tascam->dev, EP_AUDIO_IN),
c_urb->transfer_buffer, tascam->capture_urb_alloc_size,
capture_urb_complete, tascam);
c_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
}
/* MIDI URB and buffer allocation */
for (i = 0; i < NUM_MIDI_IN_URBS; i++) {
struct urb *m_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!m_urb)
goto error;
tascam->midi_in_urbs[i] = m_urb;
m_urb->transfer_buffer = usb_alloc_coherent(
tascam->dev, MIDI_IN_BUF_SIZE, GFP_KERNEL, &m_urb->transfer_dma);
if (!m_urb->transfer_buffer)
goto error;
usb_fill_bulk_urb(m_urb, tascam->dev,
usb_rcvbulkpipe(tascam->dev, EP_MIDI_IN),
m_urb->transfer_buffer, MIDI_IN_BUF_SIZE,
tascam_midi_in_urb_complete, tascam);
m_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
}
for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
struct urb *m_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!m_urb)
goto error;
tascam->midi_out_urbs[i] = m_urb;
m_urb->transfer_buffer = usb_alloc_coherent(
tascam->dev, MIDI_OUT_BUF_SIZE, GFP_KERNEL, &m_urb->transfer_dma);
if (!m_urb->transfer_buffer)
goto error;
usb_fill_bulk_urb(m_urb, tascam->dev,
usb_sndbulkpipe(tascam->dev, EP_MIDI_OUT),
m_urb->transfer_buffer, 0, /* length set later */
tascam_midi_out_urb_complete, tascam);
m_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
}
tascam->capture_ring_buffer = kmalloc(CAPTURE_RING_BUFFER_SIZE, GFP_KERNEL);
if (!tascam->capture_ring_buffer)
goto error;
tascam->capture_decode_raw_block =
kmalloc(RAW_BYTES_PER_DECODE_BLOCK, GFP_KERNEL);
if (!tascam->capture_decode_raw_block)
goto error;
tascam->capture_decode_dst_block =
kmalloc(FRAMES_PER_DECODE_BLOCK * DECODED_CHANNELS_PER_FRAME *
DECODED_SAMPLE_SIZE,
GFP_KERNEL);
if (!tascam->capture_decode_dst_block)
goto error;
tascam->capture_routing_buffer =
kmalloc(FRAMES_PER_DECODE_BLOCK * DECODED_CHANNELS_PER_FRAME *
DECODED_SAMPLE_SIZE,
GFP_KERNEL);
if (!tascam->capture_routing_buffer)
goto error;
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);
usb_kill_anchored_urbs(&tascam->capture_anchor);
atomic_set(&tascam->active_urbs, 0);
}
/**
* tascam_card_private_free() - Frees private data associated with the sound
* card.
* @card: Pointer to the ALSA sound card instance.
*
* This function is called when the sound card is being freed. It releases
* resources allocated for the tascam_card structure, including the MIDI
* input FIFO and decrements the USB device reference count.
* the reference to the USB device.
*/
static void tascam_card_private_free(struct snd_card *card) {
struct tascam_card *tascam = card->private_data;
if (tascam) {
kfifo_free(&tascam->midi_in_fifo);
if (tascam->dev) {
if (tascam && tascam->dev) {
usb_put_dev(tascam->dev);
tascam->dev = NULL;
}
}
}
/**
* tascam_suspend() - Handles device suspension.
* @intf: The USB interface being suspended.
* @message: Power management message.
*
* This function is called when the device is suspended. It stops all active
* streams, kills all URBs, and sends a vendor-specific deep sleep command
* to the device to ensure a stable low-power state.
*
* 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->capture_work);
cancel_work_sync(&tascam->midi_in_work);
cancel_work_sync(&tascam->midi_out_work);
cancel_work_sync(&tascam->stop_pcm_work);
usb_kill_anchored_urbs(&tascam->playback_anchor);
usb_kill_anchored_urbs(&tascam->capture_anchor);
usb_kill_anchored_urbs(&tascam->feedback_anchor);
usb_kill_anchored_urbs(&tascam->midi_in_anchor);
usb_kill_anchored_urbs(&tascam->midi_out_anchor);
return 0;
}
/**
* tascam_resume() - Handles device resumption from suspend.
* @intf: The USB interface being resumed.
*
* 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, or a negative error code on failure.
*/
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");
/*
* The device requires a full re-initialization sequence upon resume.
* First, 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 void tascam_error_timer(struct timer_list *t) {
struct tascam_card *tascam = container_of(t, struct tascam_card, error_timer);
if (atomic_read(&tascam->midi_in_active))
schedule_work(&tascam->midi_in_work);
if (atomic_read(&tascam->midi_out_active))
schedule_work(&tascam->midi_out_work);
}
/**
@ -404,8 +62,7 @@ static void tascam_error_timer(struct timer_list *t) {
* - Checking for the second interface (MIDI) and associating it.
* - Performing a vendor-specific handshake with the device.
* - Setting alternate settings for USB interfaces.
* - Creating and registering the ALSA sound card, PCM device, and MIDI device.
* - Allocating and initializing URBs for audio and MIDI transfers.
* - Creating and registering the ALSA sound card.
*
* Return: 0 on success, or a negative error code on failure.
*/
@ -421,13 +78,14 @@ static int tascam_probe(struct usb_interface *intf,
dev_info(&dev->dev,
"Device is connected to a USB 1.1 port, this is not supported.\n");
/* The device has two interfaces; we drive both from this driver. */
if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
tascam = usb_get_intfdata(usb_ifnum_to_if(dev, 0));
if (tascam) {
usb_set_intfdata(intf, tascam);
tascam->iface1 = intf;
}
return 0;
return 0; /* Let the core handle this interface */
}
if (dev_idx >= SNDRV_CARDS) {
@ -444,6 +102,7 @@ static int tascam_probe(struct usb_interface *intf,
if (!handshake_buf)
return -ENOMEM;
/* Perform vendor-specific handshake */
err = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), VENDOR_REQ_MODE_CONTROL,
RT_D2H_VENDOR_DEV, MODE_VAL_HANDSHAKE_READ, 0x0000,
handshake_buf, 1, USB_CTRL_TIMEOUT_MS);
@ -458,6 +117,7 @@ static int tascam_probe(struct usb_interface *intf,
return -ENODEV;
}
/* Set alternate settings to enable audio/MIDI endpoints */
err = usb_set_interface(dev, 0, 1);
if (err < 0) {
dev_err(&dev->dev, "Failed to set alt setting 1 on interface 0: %d\n", err);
@ -483,25 +143,6 @@ static int tascam_probe(struct usb_interface *intf,
tascam->card = card;
tascam->iface0 = intf;
spin_lock_init(&tascam->lock);
spin_lock_init(&tascam->midi_in_lock);
spin_lock_init(&tascam->midi_out_lock);
init_usb_anchor(&tascam->playback_anchor);
init_usb_anchor(&tascam->capture_anchor);
init_usb_anchor(&tascam->feedback_anchor);
init_usb_anchor(&tascam->midi_in_anchor);
init_usb_anchor(&tascam->midi_out_anchor);
timer_setup(&tascam->error_timer, tascam_error_timer, 0);
INIT_WORK(&tascam->stop_work, tascam_stop_work_handler);
INIT_WORK(&tascam->stop_pcm_work, tascam_stop_pcm_work_handler);
if (kfifo_alloc(&tascam->midi_in_fifo, MIDI_IN_FIFO_SIZE, GFP_KERNEL)) {
snd_card_free(card);
return -ENOMEM;
}
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));
@ -514,33 +155,6 @@ static int tascam_probe(struct usb_interface *intf,
card->shortname, USB_VID_TASCAM, dev->descriptor.idProduct,
dev_name(&dev->dev));
err = device_create_file(&dev->dev, &dev_attr_driver_version);
if (err < 0)
dev_warn(&dev->dev, "could not create driver_version attribute, err: %d\n",
err);
err = snd_pcm_new(card, "US144MKII PCM", 0, 1, 1, &tascam->pcm);
if (err < 0)
goto free_card;
tascam->pcm->private_data = tascam;
strscpy(tascam->pcm->name, "US144MKII PCM", sizeof(tascam->pcm->name));
err = tascam_init_pcm(tascam->pcm);
if (err < 0)
goto free_card;
err = tascam_create_midi(tascam);
if (err < 0)
goto free_card;
err = tascam_create_controls(tascam);
if (err < 0)
goto free_card;
err = tascam_alloc_urbs(tascam);
if (err < 0)
goto free_card;
err = snd_card_register(card);
if (err < 0)
goto free_card;
@ -560,8 +174,7 @@ 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, including killing URBs, freeing
* the sound card, and releasing memory.
* It cleans up all allocated resources by freeing the sound card.
*/
static void tascam_disconnect(struct usb_interface *intf) {
struct tascam_card *tascam = usb_get_intfdata(intf);
@ -570,27 +183,35 @@ static void tascam_disconnect(struct usb_interface *intf) {
return;
if (intf->cur_altsetting->desc.bInterfaceNumber == 0) {
device_remove_file(&tascam->dev->dev, &dev_attr_driver_version);
/* Ensure all deferred work is complete before freeing resources */
snd_card_disconnect(tascam->card);
cancel_work_sync(&tascam->stop_work);
cancel_work_sync(&tascam->capture_work);
cancel_work_sync(&tascam->midi_in_work);
cancel_work_sync(&tascam->midi_out_work);
cancel_work_sync(&tascam->stop_pcm_work);
usb_kill_anchored_urbs(&tascam->playback_anchor);
usb_kill_anchored_urbs(&tascam->capture_anchor);
usb_kill_anchored_urbs(&tascam->feedback_anchor);
usb_kill_anchored_urbs(&tascam->midi_in_anchor);
usb_kill_anchored_urbs(&tascam->midi_out_anchor);
timer_delete_sync(&tascam->error_timer);
snd_card_free(tascam->card);
dev_idx--;
}
}
/**
* tascam_suspend() - Handles device suspension.
* @intf: The USB interface being suspended.
* @message: Power management message.
*
* This function is a stub for handling device suspension.
*
* Return: 0 on success.
*/
static int tascam_suspend(struct usb_interface *intf, pm_message_t message) {
return 0;
}
/**
* tascam_resume() - Handles device resumption from suspend.
* @intf: The USB interface being resumed.
*
* This function is a stub for handling device resumption.
*
* Return: 0 on success.
*/
static int tascam_resume(struct usb_interface *intf) { return 0; }
static const struct usb_device_id tascam_usb_ids[] = {
{USB_DEVICE(USB_VID_TASCAM, USB_PID_TASCAM_US144)},
{USB_DEVICE(USB_VID_TASCAM, USB_PID_TASCAM_US144MKII)},

336
us144mkii.h
View File

@ -4,100 +4,22 @@
#ifndef __US144MKII_H
#define __US144MKII_H
#include <linux/kfifo.h>
#include <linux/timer.h>
#include <linux/usb.h>
#include <linux/workqueue.h>
#include <sound/control.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/rawmidi.h>
#define DRIVER_NAME "us144mkii"
#define DRIVER_VERSION "1.7.6"
/* --- USB Device Identification --- */
#define USB_VID_TASCAM 0x0644
#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
#define EP_MIDI_IN 0x83
#define EP_MIDI_OUT 0x04
#define EP_AUDIO_IN 0x86
/* --- USB Control Message Protocol --- */
#define RT_H2D_CLASS_EP (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT)
#define RT_D2H_CLASS_EP (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT)
#define RT_H2D_VENDOR_DEV (USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE)
#define RT_D2H_VENDOR_DEV (USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE)
enum uac_request {
UAC_SET_CUR = 0x01,
UAC_GET_CUR = 0x81,
};
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,
};
#define HANDSHAKE_SUCCESS_VAL 0x12
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 NUM_CAPTURE_URBS 8
#define CAPTURE_URB_SIZE 512
#define CAPTURE_RING_BUFFER_SIZE (CAPTURE_URB_SIZE * NUM_CAPTURE_URBS * 4)
#define NUM_MIDI_IN_URBS 4
#define MIDI_IN_BUF_SIZE 64
#define MIDI_IN_FIFO_SIZE (MIDI_IN_BUF_SIZE * NUM_MIDI_IN_URBS)
#define MIDI_OUT_BUF_SIZE 64
#define NUM_MIDI_OUT_URBS 4
#define VENDOR_REQ_MODE_CONTROL 0x49
#define MODE_VAL_HANDSHAKE_READ 0x0000
#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)
#define FEEDBACK_ACCUMULATOR_SIZE 128
/* --- Capture Decoding Defines --- */
#define DECODED_CHANNELS_PER_FRAME 4
#define DECODED_SAMPLE_SIZE 4
#define FRAMES_PER_DECODE_BLOCK 8
#define RAW_BYTES_PER_DECODE_BLOCK 512
/**
* struct tascam_card - Main driver data structure for the TASCAM US-144MKII.
@ -105,266 +27,12 @@ enum tascam_register {
* @iface0: Pointer to USB interface 0 (audio).
* @iface1: Pointer to USB interface 1 (MIDI).
* @card: Pointer to the ALSA sound card instance.
* @pcm: Pointer to the ALSA PCM device.
* @rmidi: Pointer to the ALSA rawmidi device.
*
* @playback_substream: Pointer to the active playback 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.
* @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.
* @playback_routing_buffer: Intermediate buffer for playback routing.
*
* @capture_substream: Pointer to the active capture PCM substream.
* @capture_urbs: Array of URBs for capture.
* @capture_urb_alloc_size: Size of allocated buffer for each capture URB.
* @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.
* @last_capture_period_pos: Last reported period position for capture.
* @capture_ring_buffer: Ring buffer for raw capture data from USB.
* @capture_ring_buffer_read_ptr: Read pointer for the capture ring buffer.
* @capture_ring_buffer_write_ptr: Write pointer for the capture ring buffer.
* @capture_decode_raw_block: Buffer for a raw 512-byte capture block.
* @capture_decode_dst_block: Buffer for decoded 32-bit capture samples.
* @capture_routing_buffer: Intermediate buffer for capture routing.
* @capture_work: Work struct for deferred capture processing.
* @stop_work: Work struct for deferred stream stopping.
*
* @midi_in_substream: Pointer to the active MIDI input substream.
* @midi_out_substream: Pointer to the active MIDI output substream.
* @midi_in_urbs: Array of URBs for MIDI input.
* @midi_in_active: Atomic flag indicating if MIDI input is active.
* @midi_in_fifo: FIFO for raw MIDI input data.
* @midi_in_work: Work struct for deferred MIDI input processing.
* @midi_in_lock: Spinlock for MIDI input FIFO.
* @midi_out_urbs: Array of URBs for MIDI output.
* @midi_out_active: Atomic flag indicating if MIDI output is active.
* @midi_out_work: Work struct for deferred MIDI output processing.
* @midi_out_urbs_in_flight: Bitmap of MIDI output URBs currently in flight.
* @midi_out_lock: Spinlock for MIDI output.
* @midi_running_status: Stores the last MIDI status byte for running status.
*
* @lock: Main spinlock for protecting shared driver state.
* @active_urbs: Atomic counter for active URBs.
* @current_rate: Currently configured sample rate of the device.
* @line_out_source: Source for Line Outputs (0: Playback 1-2, 1: Playback 3-4).
* @digital_out_source: Source for Digital Outputs (0: Playback 1-2, 1: Playback
* 3-4).
* @capture_12_source: Source for Capture channels 1-2 (0: Analog In, 1: Digital
* In).
* @capture_34_source: Source for Capture channels 3-4 (0: Analog In, 1: Digital
* In).
*
* @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.
* @capture_anchor: USB anchor for capture URBs.
* @feedback_anchor: USB anchor for feedback URBs.
* @midi_in_anchor: USB anchor for MIDI input URBs.
* @midi_out_anchor: USB anchor for MIDI output URBs.
*/
struct tascam_card {
/* --- Hot Path Data (frequently accessed, especially in IRQ/workqueue) --- */
spinlock_t lock; // Main lock, highly contended
atomic_t playback_active;
atomic_t capture_active;
atomic_t active_urbs; // Also frequently updated
// Playback state (updated by feedback_urb_complete and playback_urb_complete)
u64 playback_frames_consumed;
snd_pcm_uframes_t driver_playback_pos;
u64 last_period_pos;
// Capture state (updated by feedback_urb_complete and capture_urb_complete)
snd_pcm_uframes_t driver_capture_pos;
u64 capture_frames_processed;
u64 last_capture_period_pos;
// Feedback related (critical for audio sync)
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 {
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;
} fpo;
// MIDI state (frequently accessed in MIDI handlers)
atomic_t midi_in_active;
atomic_t midi_out_active;
spinlock_t midi_in_lock;
spinlock_t midi_out_lock;
unsigned long midi_out_urbs_in_flight;
u8 midi_running_status;
bool in_sysex;
struct timer_list error_timer; // Timer for MIDI error retry
int current_rate; // Also accessed frequently, moved up
/* --- Less Hot Data (pointers, configuration, work structs) --- */
struct usb_device *dev;
struct usb_interface *iface0;
struct usb_interface *iface1;
struct snd_card *card;
struct snd_pcm *pcm;
struct snd_rawmidi *rmidi;
// Substream pointers
struct snd_pcm_substream *playback_substream;
struct snd_pcm_substream *capture_substream;
struct snd_rawmidi_substream *midi_in_substream;
struct snd_rawmidi_substream *midi_out_substream;
// URB arrays and sizes
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 urb *capture_urbs[NUM_CAPTURE_URBS];
size_t capture_urb_alloc_size;
struct urb *midi_in_urbs[NUM_MIDI_IN_URBS];
struct urb *midi_out_urbs[NUM_MIDI_OUT_URBS];
// Buffers (pointers to external allocations)
u8 *capture_ring_buffer;
size_t capture_ring_buffer_read_ptr;
size_t capture_ring_buffer_write_ptr;
u8 *capture_decode_raw_block;
s32 *capture_decode_dst_block;
s32 *capture_routing_buffer;
// Work structs
struct work_struct capture_work;
struct work_struct stop_work;
struct work_struct stop_pcm_work;
struct work_struct midi_in_work;
struct work_struct midi_out_work;
// FIFOs
struct kfifo midi_in_fifo;
// Routing Matrix settings
unsigned int line_out_source;
unsigned int digital_out_source;
unsigned int capture_12_source;
unsigned int capture_34_source;
// USB anchors
struct usb_anchor playback_anchor;
struct usb_anchor capture_anchor;
struct usb_anchor feedback_anchor;
struct usb_anchor midi_in_anchor;
struct usb_anchor midi_out_anchor;
};
/* main */
/**
* tascam_free_urbs() - Free all allocated URBs and associated buffers.
* @tascam: the tascam_card instance
*
* This function kills, unlinks, and frees all playback, feedback, capture,
* and MIDI URBs, along with their transfer buffers and the capture
* ring/decode 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, feedback,
* capture, and MIDI, as well as the necessary buffers for data processing.
*
* 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,
* capture) and reset the active_urbs counter. It is used to gracefully stop
* streams from a workqueue context.
*/
void tascam_stop_work_handler(struct work_struct *work);
/**
* 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);
/* us144mkii_pcm.h */
#include "us144mkii_pcm.h"
/* us144mkii_midi.c */
/**
* tascam_midi_in_urb_complete() - Completion handler for MIDI IN URBs
* @urb: The completed URB.
*
* This function runs in interrupt context. It places the raw data from the
* USB endpoint into a kfifo and schedules a work item to process it later,
* ensuring the interrupt handler remains fast.
*/
void tascam_midi_in_urb_complete(struct urb *urb);
/**
* tascam_midi_out_urb_complete() - Completion handler for MIDI OUT bulk URB.
* @urb: The completed URB.
*
* This function runs in interrupt context. It marks the output URB as no
* longer in-flight. It then re-schedules the work handler to check for and
* send any more data waiting in the ALSA buffer. This is a safe, non-blocking
* way to continue the data transmission chain.
*/
void tascam_midi_out_urb_complete(struct urb *urb);
/**
* tascam_create_midi() - Create and initialize the ALSA rawmidi device.
* @tascam: The driver instance.
*
* Return: 0 on success, or a negative error code on failure.
*/
int tascam_create_midi(struct tascam_card *tascam);
/* us144mkii_controls.c */
/**
* tascam_create_controls() - Creates and adds ALSA mixer controls for the
* device.
* @tascam: The driver instance.
*
* This function registers custom ALSA controls for managing audio routing
* (line out source, digital out source, capture 1-2 source, capture 3-4 source)
* and displaying the current sample rate.
*
* Return: 0 on success, or a negative error code on failure.
*/
int tascam_create_controls(struct tascam_card *tascam);
#endif /* __US144MKII_H */

303
us144mkii_capture.c
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@ -1,303 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
#include "us144mkii.h"
/**
* tascam_capture_open() - Opens the PCM capture substream.
* @substream: The ALSA PCM substream to open.
*
* This function sets the hardware parameters for the capture substream
* and stores a reference to the substream in the driver's private data.
*
* Return: 0 on success.
*/
static int tascam_capture_open(struct snd_pcm_substream *substream) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
substream->runtime->hw = tascam_pcm_hw;
tascam->capture_substream = substream;
atomic_set(&tascam->capture_active, 0);
return 0;
}
/**
* tascam_capture_close() - Closes the PCM capture substream.
* @substream: The ALSA PCM substream to close.
*
* This function clears the reference to the capture substream in the
* driver's private data.
*
* Return: 0 on success.
*/
static int tascam_capture_close(struct snd_pcm_substream *substream) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
tascam->capture_substream = NULL;
return 0;
}
/**
* tascam_capture_prepare() - Prepares the PCM capture substream for use.
* @substream: The ALSA PCM substream to prepare.
*
* This function initializes capture-related counters and ring buffer pointers.
*
* Return: 0 on success.
*/
static int tascam_capture_prepare(struct snd_pcm_substream *substream) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
tascam->driver_capture_pos = 0;
tascam->capture_frames_processed = 0;
tascam->last_capture_period_pos = 0;
tascam->capture_ring_buffer_read_ptr = 0;
tascam->capture_ring_buffer_write_ptr = 0;
return 0;
}
/**
* tascam_capture_pointer() - Returns the current capture pointer position.
* @substream: The ALSA PCM substream.
*
* This function returns the current position of the capture pointer within
* the ALSA ring buffer, in frames.
*
* Return: The current capture pointer position in frames.
*/
static snd_pcm_uframes_t
tascam_capture_pointer(struct snd_pcm_substream *substream) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
u64 pos;
if (!atomic_read(&tascam->capture_active))
return 0;
guard(spinlock_irqsave)(&tascam->lock);
pos = tascam->capture_frames_processed;
if (runtime->buffer_size == 0)
return 0;
u64 remainder = do_div(pos, runtime->buffer_size);
return runtime ? remainder : 0;
}
/**
* tascam_capture_ops - ALSA PCM operations for capture.
*
* This structure defines the callback functions for capture stream operations,
* including open, close, ioctl, hardware parameters, hardware free, prepare,
* trigger, and pointer.
*/
const struct snd_pcm_ops tascam_capture_ops = {
.open = tascam_capture_open,
.close = tascam_capture_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = tascam_pcm_hw_params,
.hw_free = tascam_pcm_hw_free,
.prepare = tascam_capture_prepare,
.trigger = tascam_pcm_trigger,
.pointer = tascam_capture_pointer,
};
/**
* decode_tascam_capture_block() - Decodes a raw 512-byte block from the device.
* @src_block: Pointer to the 512-byte raw source block.
* @dst_block: Pointer to the destination buffer for decoded audio frames.
*
* The device sends audio data in a complex, multiplexed format. This function
* demultiplexes the bits from the raw block into 8 frames of 4-channel,
* 24-bit audio (stored in 32-bit containers).
*/
static void decode_tascam_capture_block(const u8 *src_block, s32 *dst_block) {
int frame, bit;
memset(dst_block, 0,
FRAMES_PER_DECODE_BLOCK * DECODED_CHANNELS_PER_FRAME *
DECODED_SAMPLE_SIZE);
for (frame = 0; frame < FRAMES_PER_DECODE_BLOCK; ++frame) {
const u8 *p_src_frame_base = src_block + frame * 64;
s32 *p_dst_frame = dst_block + frame * 4;
s32 ch[4] = {0};
for (bit = 0; bit < 24; ++bit) {
u8 byte1 = p_src_frame_base[bit];
u8 byte2 = p_src_frame_base[bit + 32];
ch[0] = (ch[0] << 1) | (byte1 & 1);
ch[2] = (ch[2] << 1) | ((byte1 >> 1) & 1);
ch[1] = (ch[1] << 1) | (byte2 & 1);
ch[3] = (ch[3] << 1) | ((byte2 >> 1) & 1);
}
/*
* The result is a 24-bit sample. Shift left by 8 to align it to
* the most significant bits of a 32-bit integer (S32_LE format).
*/
p_dst_frame[0] = ch[0] << 8;
p_dst_frame[1] = ch[1] << 8;
p_dst_frame[2] = ch[2] << 8;
p_dst_frame[3] = ch[3] << 8;
}
}
/**
* tascam_capture_work_handler() - Deferred work for processing capture data.
* @work: the work_struct instance
*
* This function runs in a kernel thread context, not an IRQ context. It reads
* raw data from the capture ring buffer, decodes it, applies routing, and
* copies the final audio data into the ALSA capture ring buffer. This offloads
* * the CPU-intensive decoding from the time-sensitive URB completion handlers.
*/
void tascam_capture_work_handler(struct work_struct *work) {
struct tascam_card *tascam =
container_of(work, struct tascam_card, capture_work);
struct snd_pcm_substream *substream = tascam->capture_substream;
struct snd_pcm_runtime *runtime;
u8 *raw_block = tascam->capture_decode_raw_block;
s32 *decoded_block = tascam->capture_decode_dst_block;
s32 *routed_block = tascam->capture_routing_buffer;
if (!substream || !substream->runtime)
return;
runtime = substream->runtime;
if (!raw_block || !decoded_block || !routed_block) {
dev_err(tascam->card->dev,
"Capture decode/routing buffers not allocated!\n");
return;
}
while (atomic_read(&tascam->capture_active)) {
size_t write_ptr, read_ptr, available_data;
bool can_process;
{
guard(spinlock_irqsave)(&tascam->lock);
write_ptr = tascam->capture_ring_buffer_write_ptr;
read_ptr = tascam->capture_ring_buffer_read_ptr;
available_data = (write_ptr >= read_ptr)
? (write_ptr - read_ptr)
: (CAPTURE_RING_BUFFER_SIZE - read_ptr + write_ptr);
can_process = (available_data >= RAW_BYTES_PER_DECODE_BLOCK);
if (can_process) {
size_t bytes_to_end = CAPTURE_RING_BUFFER_SIZE - read_ptr;
if (bytes_to_end >= RAW_BYTES_PER_DECODE_BLOCK) {
memcpy(raw_block, tascam->capture_ring_buffer + read_ptr,
RAW_BYTES_PER_DECODE_BLOCK);
} else {
memcpy(raw_block, tascam->capture_ring_buffer + read_ptr,
bytes_to_end);
memcpy(raw_block + bytes_to_end, tascam->capture_ring_buffer,
RAW_BYTES_PER_DECODE_BLOCK - bytes_to_end);
}
tascam->capture_ring_buffer_read_ptr =
(read_ptr + RAW_BYTES_PER_DECODE_BLOCK) % CAPTURE_RING_BUFFER_SIZE;
}
}
if (!can_process)
break;
decode_tascam_capture_block(raw_block, decoded_block);
process_capture_routing_us144mkii(tascam, decoded_block, routed_block);
{
guard(spinlock_irqsave)(&tascam->lock);
if (atomic_read(&tascam->capture_active)) {
int f;
for (f = 0; f < FRAMES_PER_DECODE_BLOCK; ++f) {
u8 *dst_frame_start =
runtime->dma_area +
frames_to_bytes(runtime, tascam->driver_capture_pos);
s32 *routed_frame_start = routed_block + (f * NUM_CHANNELS);
int c;
for (c = 0; c < NUM_CHANNELS; c++) {
u8 *dst_channel = dst_frame_start + (c * BYTES_PER_SAMPLE);
s32 *src_channel_s32 = routed_frame_start + c;
memcpy(dst_channel, ((char *)src_channel_s32) + 1, 3);
}
tascam->driver_capture_pos =
(tascam->driver_capture_pos + 1) % runtime->buffer_size;
}
}
}
}
}
/**
* capture_urb_complete() - Completion handler for capture bulk URBs.
* @urb: the completed URB
*
* This function runs in interrupt context. It copies the received raw data
* into an intermediate ring buffer and then schedules the workqueue to process
* it. It then resubmits the URB to receive more data.
*/
void capture_urb_complete(struct urb *urb) {
struct tascam_card *tascam = urb->context;
int ret;
if (urb->status) {
if (urb->status != -ENOENT && urb->status != -ECONNRESET &&
urb->status != -ESHUTDOWN && urb->status != -ENODEV &&
urb->status != -EPROTO)
dev_err_ratelimited(tascam->card->dev, "Capture URB failed: %d\n",
urb->status);
goto out;
}
if (!tascam || !atomic_read(&tascam->capture_active))
goto out;
if (urb->actual_length > 0) {
size_t write_ptr;
size_t bytes_to_end;
{
guard(spinlock_irqsave)(&tascam->lock);
write_ptr = tascam->capture_ring_buffer_write_ptr;
bytes_to_end = CAPTURE_RING_BUFFER_SIZE - write_ptr;
if (urb->actual_length > bytes_to_end) {
memcpy(tascam->capture_ring_buffer + write_ptr, urb->transfer_buffer,
bytes_to_end);
memcpy(tascam->capture_ring_buffer, urb->transfer_buffer + bytes_to_end,
urb->actual_length - bytes_to_end);
} else {
memcpy(tascam->capture_ring_buffer + write_ptr, urb->transfer_buffer,
urb->actual_length);
}
tascam->capture_ring_buffer_write_ptr =
(write_ptr + urb->actual_length) % CAPTURE_RING_BUFFER_SIZE;
}
schedule_work(&tascam->capture_work);
}
usb_get_urb(urb);
usb_anchor_urb(urb, &tascam->capture_anchor);
ret = usb_submit_urb(urb, GFP_ATOMIC);
if (ret < 0) {
dev_err_ratelimited(tascam->card->dev,
"Failed to resubmit capture 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);
}

411
us144mkii_controls.c
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@ -1,411 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
#include "us144mkii.h"
/**
* @brief Text descriptions for playback output source options.
*
* Used by ALSA kcontrol elements to provide user-friendly names for
* the playback routing options (e.g., "Playback 1-2", "Playback 3-4").
*/
static const char *const playback_source_texts[] = {"Playback 1-2",
"Playback 3-4"};
/**
* @brief Text descriptions for capture input source options.
*
* Used by ALSA kcontrol elements to provide user-friendly names for
* the capture routing options (e.g., "Analog In", "Digital In").
*/
static const char *const capture_source_texts[] = {"Analog In", "Digital In"};
/**
* tascam_playback_source_info() - ALSA control info callback for playback
* source.
* @kcontrol: The ALSA kcontrol instance.
* @uinfo: The ALSA control element info structure to fill.
*
* This function provides information about the enumerated playback source
* control, including its type, count, and available items (Playback 1-2,
* Playback 3-4).
*
* Return: 0 on success.
*/
static int tascam_playback_source_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo) {
return snd_ctl_enum_info(uinfo, 1, 2, playback_source_texts);
}
/**
* tascam_line_out_get() - ALSA control get callback for Line Outputs Source.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure to fill.
*
* This function retrieves the current selection for the Line Outputs source
* (Playback 1-2 or Playback 3-4) from the driver's private data and populates
* the ALSA control element value.
*
* Return: 0 on success.
*/
static int tascam_line_out_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
ucontrol->value.enumerated.item[0] = tascam->line_out_source;
return 0;
}
/**
* tascam_line_out_put() - ALSA control put callback for Line Outputs Source.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure containing the new value.
*
* This function sets the Line Outputs source (Playback 1-2 or Playback 3-4)
* based on the user's selection from the ALSA control element. It validates
* the input and updates the driver's private data.
*
* Return: 1 if the value was changed, 0 if unchanged, or a negative error code.
*/
static int tascam_line_out_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
if (ucontrol->value.enumerated.item[0] > 1)
return -EINVAL;
if (tascam->line_out_source == ucontrol->value.enumerated.item[0])
return 0;
tascam->line_out_source = ucontrol->value.enumerated.item[0];
return 1;
}
/**
* tascam_line_out_control - ALSA kcontrol definition for Line Outputs Source.
*
* This defines a new ALSA mixer control named "Line OUTPUTS Source" that allows
* the user to select between "Playback 1-2" and "Playback 3-4" for the analog
* line outputs of the device. It uses the `tascam_playback_source_info` for
* information and `tascam_line_out_get`/`tascam_line_out_put` for value
* handling.
*/
static const struct snd_kcontrol_new tascam_line_out_control = {
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "Line OUTPUTS Source",
.info = tascam_playback_source_info,
.get = tascam_line_out_get,
.put = tascam_line_out_put,
};
/**
* tascam_digital_out_get() - ALSA control get callback for Digital Outputs
* Source.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure to fill.
*
* This function retrieves the current selection for the Digital Outputs source
* (Playback 1-2 or Playback 3-4) from the driver's private data and populates
* the ALSA control element value.
*
* Return: 0 on success.
*/
static int tascam_digital_out_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
ucontrol->value.enumerated.item[0] = tascam->digital_out_source;
return 0;
}
/**
* tascam_digital_out_put() - ALSA control put callback for Digital Outputs
* Source.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure containing the new value.
*
* This function sets the Digital Outputs source (Playback 1-2 or Playback 3-4)
* based on the user's selection from the ALSA control element. It validates
* the input and updates the driver's private data.
*
* Return: 1 if the value was changed, 0 if unchanged, or a negative error code.
*/
static int tascam_digital_out_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
if (ucontrol->value.enumerated.item[0] > 1)
return -EINVAL;
if (tascam->digital_out_source == ucontrol->value.enumerated.item[0])
return 0;
tascam->digital_out_source = ucontrol->value.enumerated.item[0];
return 1;
}
/**
* tascam_digital_out_control - ALSA kcontrol definition for Digital Outputs
* Source.
*
* This defines a new ALSA mixer control named "Digital OUTPUTS Source" that
* allows the user to select between "Playback 1-2" and "Playback 3-4" for the
* digital outputs of the device. It uses the `tascam_playback_source_info` for
* information and `tascam_digital_out_get`/`tascam_digital_out_put` for value
* handling.
*/
static const struct snd_kcontrol_new tascam_digital_out_control = {
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "Digital OUTPUTS Source",
.info = tascam_playback_source_info,
.get = tascam_digital_out_get,
.put = tascam_digital_out_put,
};
/**
* tascam_capture_source_info() - ALSA control info callback for capture source.
* @kcontrol: The ALSA kcontrol instance.
* @uinfo: The ALSA control element info structure to fill.
*
* This function provides information about the enumerated capture source
* control, including its type, count, and available items (Analog In, Digital
* In).
*
* Return: 0 on success.
*/
static int tascam_capture_source_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo) {
return snd_ctl_enum_info(uinfo, 1, 2, capture_source_texts);
}
/**
* tascam_capture_12_get() - ALSA control get callback for Capture channels 1
* and 2 Source.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure to fill.
*
* This function retrieves the current selection for the Capture channels 1 and
* 2 source (Analog In or Digital In) from the driver's private data and
* populates the ALSA control element value.
*
* Return: 0 on success.
*/
static int tascam_capture_12_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
ucontrol->value.enumerated.item[0] = tascam->capture_12_source;
return 0;
}
/**
* tascam_capture_12_put() - ALSA control put callback for Capture channels 1
* and 2 Source.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure containing the new value.
*
* This function sets the Capture channels 1 and 2 source (Analog In or Digital
* In) based on the user's selection from the ALSA control element. It validates
* the input and updates the driver's private data.
*
* Return: 1 if the value was changed, 0 if unchanged, or a negative error code.
*/
static int tascam_capture_12_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
if (ucontrol->value.enumerated.item[0] > 1)
return -EINVAL;
if (tascam->capture_12_source == ucontrol->value.enumerated.item[0])
return 0;
tascam->capture_12_source = ucontrol->value.enumerated.item[0];
return 1;
}
/**
* tascam_capture_12_control - ALSA kcontrol definition for Capture channels 1
* and 2 Source.
*
* This defines a new ALSA mixer control named "ch1 and ch2 Source" that allows
* the user to select between "Analog In" and "Digital In" for the first two
* capture channels of the device. It uses the `tascam_capture_source_info` for
* information and `tascam_capture_12_get`/`tascam_capture_12_put` for value
* handling.
*/
static const struct snd_kcontrol_new tascam_capture_12_control = {
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "ch1 and ch2 Source",
.info = tascam_capture_source_info,
.get = tascam_capture_12_get,
.put = tascam_capture_12_put,
};
/**
* tascam_capture_34_get() - ALSA control get callback for Capture channels 3
* and 4 Source.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure to fill.
*
* This function retrieves the current selection for the Capture channels 3 and
* 4 source (Analog In or Digital In) from the driver's private data and
* populates the ALSA control element value.
*
* Return: 0 on success.
*/
static int tascam_capture_34_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
ucontrol->value.enumerated.item[0] = tascam->capture_34_source;
return 0;
}
/**
* tascam_capture_34_put() - ALSA control put callback for Capture channels 3
* and 4 Source.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure containing the new value.
*
* This function sets the Capture channels 3 and 4 source (Analog In or Digital
* In) based on the user's selection from the ALSA control element. It validates
* the input and updates the driver's private data.
*
* Return: 1 if the value was changed, 0 if unchanged, or a negative error code.
*/
static int tascam_capture_34_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
if (ucontrol->value.enumerated.item[0] > 1)
return -EINVAL;
if (tascam->capture_34_source == ucontrol->value.enumerated.item[0])
return 0;
tascam->capture_34_source = ucontrol->value.enumerated.item[0];
return 1;
}
/**
* tascam_capture_34_control - ALSA kcontrol definition for Capture channels 3
* and 4 Source.
*
* This defines a new ALSA mixer control named "ch3 and ch4 Source" that allows
* the user to select between "Analog In" and "Digital In" for the third and
* fourth capture channels of the device. It uses the
* `tascam_capture_source_info` for information and
* `tascam_capture_34_get`/`tascam_capture_34_put` for value handling.
*/
static const struct snd_kcontrol_new tascam_capture_34_control = {
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "ch3 and ch4 Source",
.info = tascam_capture_source_info,
.get = tascam_capture_34_get,
.put = tascam_capture_34_put,
};
/**
* tascam_samplerate_info() - ALSA control info callback for Sample Rate.
* @kcontrol: The ALSA kcontrol instance.
* @uinfo: The ALSA control element info structure to fill.
*
* This function provides information about the Sample Rate control, defining
* it as an integer type with a minimum value of 0 and a maximum of 96000.
*
* Return: 0 on success.
*/
static int tascam_samplerate_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo) {
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = 1;
uinfo->value.integer.min = 0;
uinfo->value.integer.max = 96000;
return 0;
}
/**
* tascam_samplerate_get() - ALSA control get callback for Sample Rate.
* @kcontrol: The ALSA kcontrol instance.
* @ucontrol: The ALSA control element value structure to fill.
*
* This function retrieves the current sample rate from the device via a USB
* control message and populates the ALSA control element value. If the rate
* is already known (i.e., `current_rate` is set), it returns that value
* directly.
*
* Return: 0 on success, or a negative error code on failure.
*/
static int tascam_samplerate_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol) {
struct tascam_card *tascam =
(struct tascam_card *)snd_kcontrol_chip(kcontrol);
u8 *buf __free(kfree);
int err;
u32 rate = 0;
if (tascam->current_rate > 0) {
ucontrol->value.integer.value[0] = tascam->current_rate;
return 0;
}
buf = kmalloc(3, GFP_KERNEL);
if (!buf)
return -ENOMEM;
err = usb_control_msg(tascam->dev, usb_rcvctrlpipe(tascam->dev, 0),
UAC_GET_CUR, RT_D2H_CLASS_EP, UAC_SAMPLING_FREQ_CONTROL,
EP_AUDIO_IN, buf, 3, USB_CTRL_TIMEOUT_MS);
if (err >= 3)
rate = buf[0] | (buf[1] << 8) | (buf[2] << 16);
ucontrol->value.integer.value[0] = rate;
return 0;
}
/**
* tascam_samplerate_control - ALSA kcontrol definition for Sample Rate.
*
* This defines a new ALSA mixer control named "Sample Rate" that displays
* the current sample rate of the device. It is a read-only control.
*/
static const struct snd_kcontrol_new tascam_samplerate_control = {
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "Sample Rate",
.info = tascam_samplerate_info,
.get = tascam_samplerate_get,
.access = SNDRV_CTL_ELEM_ACCESS_READ,
};
/**
* tascam_create_controls() - Creates and adds ALSA mixer controls for the
* device.
* @tascam: The driver instance.
*
* This function registers custom ALSA controls for managing audio routing
* (line out source, digital out source, capture 1-2 source, capture 3-4 source)
* and displaying the current sample rate.
*
* Return: 0 on success, or a negative error code on failure.
*/
int tascam_create_controls(struct tascam_card *tascam) {
int err;
err =
snd_ctl_add(tascam->card, snd_ctl_new1(&tascam_line_out_control, tascam));
if (err < 0)
return err;
err = snd_ctl_add(tascam->card,
snd_ctl_new1(&tascam_digital_out_control, tascam));
if (err < 0)
return err;
err = snd_ctl_add(tascam->card,
snd_ctl_new1(&tascam_capture_12_control, tascam));
if (err < 0)
return err;
err = snd_ctl_add(tascam->card,
snd_ctl_new1(&tascam_capture_34_control, tascam));
if (err < 0)
return err;
err = snd_ctl_add(tascam->card,
snd_ctl_new1(&tascam_samplerate_control, tascam));
if (err < 0)
return err;
return 0;
}

397
us144mkii_midi.c
View File

@ -1,397 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
#include "us144mkii.h"
/**
* tascam_midi_in_work_handler() - Deferred work for processing MIDI input.
* @work: The work_struct instance.
*
* This function runs in a thread context. It safely reads raw USB data from
* the kfifo, processes it by stripping protocol-specific padding bytes, and
* passes the clean MIDI data to the ALSA rawmidi subsystem.
*/
static void tascam_midi_in_work_handler(struct work_struct *work) {
struct tascam_card *tascam =
container_of(work, struct tascam_card, midi_in_work);
u8 buf[9];
u8 clean_buf[8];
unsigned int count, clean_count;
if (!tascam->midi_in_substream)
return;
while (kfifo_out_spinlocked(&tascam->midi_in_fifo, buf, sizeof(buf),
&tascam->midi_in_lock) == sizeof(buf)) {
clean_count = 0;
for (count = 0; count < 8; ++count) {
if (buf[count] != 0xfd)
clean_buf[clean_count++] = buf[count];
}
if (clean_count > 0)
snd_rawmidi_receive(tascam->midi_in_substream, clean_buf, clean_count);
}
}
/**
* tascam_midi_in_urb_complete() - Completion handler for MIDI IN URBs
* @urb: The completed URB.
*
* This function runs in interrupt context. It places the raw data from the
* USB endpoint into a kfifo and schedules a work item to process it later,
* ensuring the interrupt handler remains fast.
*/
void tascam_midi_in_urb_complete(struct urb *urb) {
struct tascam_card *tascam = urb->context;
int ret;
if (urb->status) {
if (urb->status != -ENOENT && urb->status != -ECONNRESET &&
urb->status != -ESHUTDOWN && urb->status != -EPROTO) {
dev_err_ratelimited(tascam->card->dev, "MIDI IN URB failed: status %d\n",
urb->status);
}
goto out;
}
if (tascam && atomic_read(&tascam->midi_in_active) &&
urb->actual_length > 0) {
kfifo_in_spinlocked(&tascam->midi_in_fifo, urb->transfer_buffer,
urb->actual_length, &tascam->midi_in_lock);
schedule_work(&tascam->midi_in_work);
}
usb_get_urb(urb);
usb_anchor_urb(urb, &tascam->midi_in_anchor);
ret = usb_submit_urb(urb, GFP_ATOMIC);
if (ret < 0) {
dev_err(tascam->card->dev, "Failed to resubmit MIDI IN URB: error %d\n",
ret);
usb_unanchor_urb(urb);
usb_put_urb(urb);
}
out:
usb_put_urb(urb);
}
/**
* tascam_midi_in_open() - Opens the MIDI input substream.
* @substream: The ALSA rawmidi substream to open.
*
* This function stores a reference to the MIDI input substream in the
* driver's private data.
*
* Return: 0 on success.
*/
static int tascam_midi_in_open(struct snd_rawmidi_substream *substream) {
struct tascam_card *tascam = substream->rmidi->private_data;
tascam->midi_in_substream = substream;
return 0;
}
/**
* tascam_midi_in_close() - Closes the MIDI input substream.
* @substream: The ALSA rawmidi substream to close.
*
* Return: 0 on success.
*/
static int tascam_midi_in_close(struct snd_rawmidi_substream *substream) {
return 0;
}
/**
* tascam_midi_in_trigger() - Triggers MIDI input stream activity.
* @substream: The ALSA rawmidi substream.
* @up: Boolean indicating whether to start (1) or stop (0) the stream.
*
* This function starts or stops the MIDI input URBs based on the 'up'
* parameter. When starting, it resets the kfifo and submits all MIDI input
* URBs. When stopping, it kills all anchored MIDI input URBs and cancels the
* associated workqueue.
*/
static void tascam_midi_in_trigger(struct snd_rawmidi_substream *substream,
int up) {
struct tascam_card *tascam = substream->rmidi->private_data;
int i, err;
if (up) {
if (atomic_xchg(&tascam->midi_in_active, 1) == 0) {
{
guard(spinlock_irqsave)(&tascam->midi_in_lock);
kfifo_reset(&tascam->midi_in_fifo);
}
for (i = 0; i < NUM_MIDI_IN_URBS; i++) {
usb_get_urb(tascam->midi_in_urbs[i]);
usb_anchor_urb(tascam->midi_in_urbs[i], &tascam->midi_in_anchor);
err = usb_submit_urb(tascam->midi_in_urbs[i], GFP_KERNEL);
if (err < 0) {
dev_err(tascam->card->dev, "Failed to submit MIDI IN URB %d: %d\n", i,
err);
usb_unanchor_urb(tascam->midi_in_urbs[i]);
usb_put_urb(tascam->midi_in_urbs[i]);
}
}
}
} else {
if (atomic_xchg(&tascam->midi_in_active, 0) == 1) {
usb_kill_anchored_urbs(&tascam->midi_in_anchor);
cancel_work_sync(&tascam->midi_in_work);
}
}
}
/**
* tascam_midi_in_ops - ALSA rawmidi operations for MIDI input.
*
* This structure defines the callback functions for MIDI input stream
* operations, including open, close, and trigger.
*/
static const struct snd_rawmidi_ops tascam_midi_in_ops = {
.open = tascam_midi_in_open,
.close = tascam_midi_in_close,
.trigger = tascam_midi_in_trigger,
};
/**
* tascam_midi_out_urb_complete() - Completion handler for MIDI OUT bulk URB.
* @urb: The completed URB.
*
* This function runs in interrupt context. It marks the output URB as no
* longer in-flight. It then re-schedules the work handler to check for and
* send any more data waiting in the ALSA buffer. This is a safe, non-blocking
* way to continue the data transmission chain.
*/
void tascam_midi_out_urb_complete(struct urb *urb) {
struct tascam_card *tascam = urb->context;
int i, urb_index = -1;
if (urb->status) {
if (urb->status != -ENOENT && urb->status != -ECONNRESET &&
urb->status != -ESHUTDOWN) {
dev_err_ratelimited(tascam->card->dev, "MIDI OUT URB failed: %d\n",
urb->status);
}
goto out;
}
if (!tascam)
goto out;
for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
if (tascam->midi_out_urbs[i] == urb) {
urb_index = i;
break;
}
}
if (urb_index < 0) {
dev_err_ratelimited(tascam->card->dev, "Unknown MIDI OUT URB completed!\n");
goto out;
}
{
guard(spinlock_irqsave)(&tascam->midi_out_lock);
clear_bit(urb_index, &tascam->midi_out_urbs_in_flight);
}
if (atomic_read(&tascam->midi_out_active))
schedule_work(&tascam->midi_out_work);
out:
usb_put_urb(urb);
}
/**
* tascam_midi_out_work_handler() - Deferred work for sending MIDI data
* @work: The work_struct instance.
*
* This function handles the proprietary output protocol: take the raw MIDI
* message bytes from the application, place them at the start of a 9-byte
* buffer, pad the rest with 0xFD, and add a terminator byte (0x00).
* This function pulls as many bytes as will fit into one packet from the
* ALSA buffer and sends them.
*/
static void tascam_midi_out_work_handler(struct work_struct *work) {
struct tascam_card *tascam =
container_of(work, struct tascam_card, midi_out_work);
struct snd_rawmidi_substream *substream = tascam->midi_out_substream;
int i;
if (!substream || !atomic_read(&tascam->midi_out_active))
return;
while (snd_rawmidi_transmit_peek(substream, (u8[]){0}, 1) == 1) {
int urb_index;
struct urb *urb;
u8 *buf;
int bytes_to_send;
{
guard(spinlock_irqsave)(&tascam->midi_out_lock);
urb_index = -1;
for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
if (!test_bit(i, &tascam->midi_out_urbs_in_flight)) {
urb_index = i;
break;
}
}
if (urb_index < 0) {
return; /* No free URBs, will be rescheduled by completion handler */
}
urb = tascam->midi_out_urbs[urb_index];
buf = urb->transfer_buffer;
bytes_to_send = snd_rawmidi_transmit(substream, buf, 8);
if (bytes_to_send <= 0) {
break; /* No more data */
}
if (bytes_to_send < 9)
memset(buf + bytes_to_send, 0xfd, 9 - bytes_to_send);
buf[8] = 0x00;
set_bit(urb_index, &tascam->midi_out_urbs_in_flight);
urb->transfer_buffer_length = 9;
}
usb_get_urb(urb);
usb_anchor_urb(urb, &tascam->midi_out_anchor);
if (usb_submit_urb(urb, GFP_KERNEL) < 0) {
dev_err_ratelimited(tascam->card->dev,
"Failed to submit MIDI OUT URB %d\n", urb_index);
{
guard(spinlock_irqsave)(&tascam->midi_out_lock);
clear_bit(urb_index, &tascam->midi_out_urbs_in_flight);
}
usb_unanchor_urb(urb);
usb_put_urb(urb);
break; /* Stop on error */
}
}
}
/**
* tascam_midi_out_open() - Opens the MIDI output substream.
* @substream: The ALSA rawmidi substream to open.
*
* This function stores a reference to the MIDI output substream in the
* driver's private data and initializes the MIDI running status.
*
* Return: 0 on success.
*/
static int tascam_midi_out_open(struct snd_rawmidi_substream *substream) {
struct tascam_card *tascam = substream->rmidi->private_data;
tascam->midi_out_substream = substream;
/* Initialize the running status state for the packet packer. */
tascam->midi_running_status = 0;
return 0;
}
/**
* tascam_midi_out_close() - Closes the MIDI output substream.
* @substream: The ALSA rawmidi substream to close.
*
* Return: 0 on success.
*/
static int tascam_midi_out_close(struct snd_rawmidi_substream *substream) {
return 0;
}
/**
* tascam_midi_out_drain() - Drains the MIDI output stream.
* @substream: The ALSA rawmidi substream.
*
* This function cancels any pending MIDI output work and kills all
* anchored MIDI output URBs, ensuring all data is sent or discarded.
*/
static void tascam_midi_out_drain(struct snd_rawmidi_substream *substream) {
struct tascam_card *tascam = substream->rmidi->private_data;
bool in_flight = true;
while (in_flight) {
in_flight = false;
for (int i = 0; i < NUM_MIDI_OUT_URBS; i++) {
if (test_bit(i, &tascam->midi_out_urbs_in_flight)) {
in_flight = true;
break;
}
}
if (in_flight)
schedule_timeout_uninterruptible(1);
}
cancel_work_sync(&tascam->midi_out_work);
usb_kill_anchored_urbs(&tascam->midi_out_anchor);
}
/**
* tascam_midi_out_trigger() - Triggers MIDI output stream activity.
* @substream: The ALSA rawmidi substream.
* @up: Boolean indicating whether to start (1) or stop (0) the stream.
*
* This function starts or stops the MIDI output workqueue based on the
* 'up' parameter.
*/
static void tascam_midi_out_trigger(struct snd_rawmidi_substream *substream,
int up) {
struct tascam_card *tascam = substream->rmidi->private_data;
if (up) {
atomic_set(&tascam->midi_out_active, 1);
schedule_work(&tascam->midi_out_work);
} else {
atomic_set(&tascam->midi_out_active, 0);
}
}
/**
* tascam_midi_out_ops - ALSA rawmidi operations for MIDI output.
*
* This structure defines the callback functions for MIDI output stream
* operations, including open, close, trigger, and drain.
*/
static const struct snd_rawmidi_ops tascam_midi_out_ops = {
.open = tascam_midi_out_open,
.close = tascam_midi_out_close,
.trigger = tascam_midi_out_trigger,
.drain = tascam_midi_out_drain,
};
/**
* tascam_create_midi() - Create and initialize the ALSA rawmidi device.
* @tascam: The driver instance.
*
* Return: 0 on success, or a negative error code on failure.
*/
int tascam_create_midi(struct tascam_card *tascam) {
int err;
err =
snd_rawmidi_new(tascam->card, "US144MKII MIDI", 0, 1, 1, &tascam->rmidi);
if (err < 0)
return err;
strscpy(tascam->rmidi->name, "US144MKII MIDI", sizeof(tascam->rmidi->name));
tascam->rmidi->private_data = tascam;
snd_rawmidi_set_ops(tascam->rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
&tascam_midi_in_ops);
snd_rawmidi_set_ops(tascam->rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
&tascam_midi_out_ops);
tascam->rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT |
SNDRV_RAWMIDI_INFO_OUTPUT |
SNDRV_RAWMIDI_INFO_DUPLEX;
INIT_WORK(&tascam->midi_in_work, tascam_midi_in_work_handler);
INIT_WORK(&tascam->midi_out_work, tascam_midi_out_work_handler);
return 0;
}

415
us144mkii_pcm.c
View File

@ -1,415 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
#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]--;
}
}
/**
* @brief Rate-to-Packet Fixing Data
*
* These static arrays define the number of audio frames per USB isochronous
* packet for various sample rates. This data is crucial for maintaining
* audio synchronization and preventing xruns, as the device's feedback
* mechanism indicates how many samples it has consumed.
*
* The patterns are indexed by a feedback value received from the device,
* which helps the driver adjust the packet size dynamically to match the
* device's consumption rate.
*/
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 |
SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME),
.formats = SNDRV_PCM_FMTBIT_S24_3LE,
.rates = (SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000),
.rate_min = 44100,
.rate_max = 96000,
.channels_min = NUM_CHANNELS,
.channels_max = NUM_CHANNELS,
.buffer_bytes_max = 1024 * 1024,
.period_bytes_min = 48 * BYTES_PER_FRAME,
.period_bytes_max = 1024 * BYTES_PER_FRAME,
.periods_min = 2,
.periods_max = 1024,
};
/**
* 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);
}
}
/**
* process_capture_routing_us144mkii() - Apply capture routing matrix
* @tascam: The driver instance.
* @decoded_block: Buffer containing 4 channels of S32LE decoded audio.
* @routed_block: Buffer to be filled for ALSA.
*/
void process_capture_routing_us144mkii(struct tascam_card *tascam,
const s32 *decoded_block,
s32 *routed_block) {
int f;
const s32 *src_frame;
s32 *dst_frame;
for (f = 0; f < FRAMES_PER_DECODE_BLOCK; f++) {
src_frame = decoded_block + (f * DECODED_CHANNELS_PER_FRAME);
dst_frame = routed_block + (f * DECODED_CHANNELS_PER_FRAME);
/* ch1 and ch2 Source */
if (tascam->capture_12_source == 0) { /* analog inputs */
dst_frame[0] = src_frame[0]; /* Analog L */
dst_frame[1] = src_frame[1]; /* Analog R */
} else { /* digital inputs */
dst_frame[0] = src_frame[2]; /* Digital L */
dst_frame[1] = src_frame[3]; /* Digital R */
}
/* ch3 and ch4 Source */
if (tascam->capture_34_source == 0) { /* analog inputs */
dst_frame[2] = src_frame[0]; /* Analog L (Duplicate) */
dst_frame[3] = src_frame[1]; /* Analog R (Duplicate) */
} else { /* digital inputs */
dst_frame[2] = src_frame[2]; /* Digital L */
dst_frame[3] = src_frame[3]; /* Digital R */
}
}
}
/**
* 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) {
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_IN,
rate_payload_buf, 3, 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;
}
/**
* tascam_pcm_hw_params() - Configures hardware parameters for PCM streams.
* @substream: The ALSA PCM substream.
* @params: The hardware parameters to apply.
*
* 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, or a negative error code on failure.
*/
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;
}
/**
* tascam_pcm_hw_free() - Frees hardware parameters for PCM streams.
* @substream: The ALSA PCM substream.
*
* This function frees the pages allocated for the PCM buffer.
*
* Return: 0 on success.
*/
int tascam_pcm_hw_free(struct snd_pcm_substream *substream) { return 0; }
/**
* tascam_pcm_trigger() - Triggers the start or stop of PCM streams.
* @substream: The ALSA PCM substream.
* @cmd: The trigger command (e.g., SNDRV_PCM_TRIGGER_START,
* SNDRV_PCM_TRIGGER_STOP).
*
* This function handles starting and stopping of playback and capture streams
* by submitting or killing the associated URBs. It ensures that both streams
* are started/stopped together.
*
* Return: 0 on success, or a negative error code on failure.
*/
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:
case SNDRV_PCM_TRIGGER_RESUME:
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:
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
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);
}
for (i = 0; i < NUM_CAPTURE_URBS; i++) {
usb_get_urb(tascam->capture_urbs[i]);
usb_anchor_urb(tascam->capture_urbs[i], &tascam->capture_anchor);
err = usb_submit_urb(tascam->capture_urbs[i], GFP_ATOMIC);
if (err < 0) {
usb_unanchor_urb(tascam->capture_urbs[i]);
usb_put_urb(tascam->capture_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;
}
int tascam_init_pcm(struct snd_pcm *pcm) {
struct tascam_card *tascam = pcm->private_data;
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &tascam_playback_ops);
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &tascam_capture_ops);
snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
tascam->dev->dev.parent, 64 * 1024,
tascam_pcm_hw.buffer_bytes_max);
INIT_WORK(&tascam->capture_work, tascam_capture_work_handler);
return 0;
}

204
us144mkii_pcm.h
View File

@ -1,204 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0-only */
// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
#ifndef __US144MKII_PCM_H
#define __US144MKII_PCM_H
#include "us144mkii.h"
/**
* tascam_pcm_hw - Hardware capabilities for TASCAM US-144MKII PCM.
*
* Defines the supported PCM formats, rates, channels, and buffer/period sizes
* for the TASCAM US-144MKII audio interface.
*/
extern const struct snd_pcm_hardware tascam_pcm_hw;
/**
* tascam_playback_ops - ALSA PCM operations for playback.
*
* This structure defines the callback functions for playback stream operations,
* including open, close, ioctl, hardware parameters, hardware free, prepare,
* trigger, and pointer.
*/
extern const struct snd_pcm_ops tascam_playback_ops;
/**
* tascam_capture_ops - ALSA PCM operations for capture.
*
* This structure defines the callback functions for capture stream operations,
* including open, close, ioctl, hardware parameters, hardware free, prepare,
* trigger, and pointer.
*/
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 (applying routing), 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);
/**
* capture_urb_complete() - Completion handler for capture bulk URBs.
* @urb: the completed URB
*
* This function runs in interrupt context. It copies the received raw data
* into an intermediate ring buffer and then schedules the workqueue to process
* it. It then resubmits the URB to receive more data.
*/
void capture_urb_complete(struct urb *urb);
/**
* prepare_playback_urb() - Prepares and submits a playback URB.
* @tascam: the tascam_card instance
*
* This function gets a free playback URB, calculates the number of frames to
* send based on the feedback accumulator, copies audio data from the ALSA
* ring buffer, applies routing, and submits the URB.
*/
void prepare_playback_urb(struct tascam_card *tascam);
/**
* 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);
/**
* retire_capture_urb() - Completion handler for capture bulk URBs.
* @urb: the completed URB
*
* This function runs in interrupt context. It copies the received raw data
* into an intermediate ring buffer and then schedules the workqueue to process
* it. It then calls prepare_capture_urb() to submit the next URB.
*/
void retire_capture_urb(struct urb *urb);
/**
* prepare_capture_urb() - Prepares and submits a capture URB.
* @tascam: the tascam_card instance
*
* This function gets a free capture URB from the anchor and submits it.
*/
void prepare_capture_urb(struct tascam_card *tascam);
/**
* tascam_init_pcm() - Initializes the ALSA PCM device.
* @pcm: Pointer to the ALSA PCM device to initialize.
*
* This function sets up the PCM operations, adds ALSA controls for routing
* and sample rate, and preallocates pages for the PCM buffer.
*
* Return: 0 on success, or a negative error code on failure.
*/
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);
/**
* process_capture_routing_us144mkii() - Apply capture routing matrix
* @tascam: The driver instance.
* @decoded_block: Buffer containing 4 channels of S32LE decoded audio.
* @routed_block: Buffer to be filled for ALSA.
*/
void process_capture_routing_us144mkii(struct tascam_card *tascam,
const s32 *decoded_block,
s32 *routed_block);
/**
* tascam_pcm_hw_params() - Configures hardware parameters for PCM streams.
* @substream: The ALSA PCM substream.
* @params: The hardware parameters to apply.
*
* 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, or a negative error code on failure.
*/
int tascam_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params);
/**
* tascam_pcm_hw_free() - Frees hardware parameters for PCM streams.
* @substream: The ALSA PCM substream.
*
* This function frees the pages allocated for the PCM buffer.
*
* Return: 0 on success.
*/
int tascam_pcm_hw_free(struct snd_pcm_substream *substream);
/**
* tascam_pcm_trigger() - Triggers the start or stop of PCM streams.
* @substream: The ALSA PCM substream.
* @cmd: The trigger command (e.g., SNDRV_PCM_TRIGGER_START,
* SNDRV_PCM_TRIGGER_STOP).
*
* This function handles starting and stopping of playback and capture streams
* by submitting or killing the associated URBs. It ensures that both streams
* are started/stopped together.
*
* Return: 0 on success, or a negative error code on failure.
*/
int tascam_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
/**
* tascam_capture_work_handler() - Deferred work for processing capture data.
* @work: the work_struct instance
*
* This function runs in a kernel thread context, not an IRQ context. It reads
* raw data from the capture ring buffer, decodes it, applies routing, and
* copies the final audio data into the ALSA capture ring buffer. This offloads
* * the CPU-intensive decoding from the time-sensitive URB completion handlers.
*/
void tascam_capture_work_handler(struct work_struct *work);
#endif /* __US144MKII_PCM_H */

443
us144mkii_playback.c
View File

@ -1,443 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
#include "us144mkii.h"
/**
* tascam_playback_open() - Opens the PCM playback substream.
* @substream: The ALSA PCM substream to open.
*
* This function sets the hardware parameters for the playback substream
* and stores a reference to the substream in the driver's private data.
*
* Return: 0 on success.
*/
static int tascam_playback_open(struct snd_pcm_substream *substream) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
substream->runtime->hw = tascam_pcm_hw;
tascam->playback_substream = substream;
atomic_set(&tascam->playback_active, 0);
return 0;
}
/**
* tascam_playback_close() - Closes the PCM playback substream.
* @substream: The ALSA PCM substream to close.
*
* This function clears the reference to the playback substream in the
* driver's private data.
*
* Return: 0 on success.
*/
static int tascam_playback_close(struct snd_pcm_substream *substream) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
tascam->playback_substream = NULL;
return 0;
}
/**
* tascam_playback_prepare() - Prepares the PCM playback substream for use.
* @substream: The ALSA PCM substream to prepare.
*
* This function initializes playback-related counters and flags, and configures
* the playback URBs with appropriate packet sizes based on the nominal frame
* rate and feedback accumulator.
*
* 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;
}
/**
* tascam_playback_pointer() - Returns the current playback pointer position.
* @substream: The ALSA PCM substream.
*
* This function returns the current position of the playback pointer within
* the ALSA ring buffer, in frames.
*
* Return: The current playback pointer position in frames.
*/
static snd_pcm_uframes_t
tascam_playback_pointer(struct snd_pcm_substream *substream) {
struct tascam_card *tascam = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
u64 pos;
if (!atomic_read(&tascam->playback_active))
return 0;
guard(spinlock_irqsave)(&tascam->lock);
pos = tascam->playback_frames_consumed;
if (runtime->buffer_size == 0)
return 0;
u64 remainder = do_div(pos, runtime->buffer_size);
return runtime ? remainder : 0;
}
/**
* tascam_playback_ops - ALSA PCM operations for playback.
*
* This structure defines the callback functions for playback stream operations,
* including open, close, ioctl, hardware parameters, hardware free, prepare,
* trigger, and pointer.
*/
const struct snd_pcm_ops tascam_playback_ops = {
.open = tascam_playback_open,
.close = tascam_playback_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = tascam_pcm_hw_params,
.hw_free = tascam_pcm_hw_free,
.prepare = tascam_playback_prepare,
.trigger = tascam_pcm_trigger,
.pointer = tascam_playback_pointer,
};
/**
* 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;
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);
}
/* Apply routing to the contiguous data in our routing buffer */
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);
}
/**
* 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;
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);
}
/**
* 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) {
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);
}