sound/usb/line6/capture.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Line 6 Linux USB driver
  *
  * Copyright (C) 2004-2010 Markus Grabner (line6@grabner-graz.at)
  */

 #include <linux/slab.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>

 #include "capture.h"
 #include "driver.h"
 #include "pcm.h"

 /*
 	Find a free URB and submit it.
 	must be called in line6pcm->in.lock context
 */
 static int submit_audio_in_urb(struct snd_line6_pcm *line6pcm)
 {
 	int index;
 	int i, urb_size;
 	int ret;
 	struct urb *urb_in;

 	index = find_first_zero_bit(&line6pcm->in.active_urbs,
 				    line6pcm->line6->iso_buffers);

 	if (index < 0 || index >= line6pcm->line6->iso_buffers) {
 		dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
 		return -EINVAL;
 	}

 	urb_in = line6pcm->in.urbs[index];
 	urb_size = 0;

 	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
 		struct usb_iso_packet_descriptor *fin =
 		    &urb_in->iso_frame_desc[i];
 		fin->offset = urb_size;
 		fin->length = line6pcm->max_packet_size_in;
 		urb_size += line6pcm->max_packet_size_in;
 	}

 	urb_in->transfer_buffer =
 	    line6pcm->in.buffer +
 	    index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_in;
 	urb_in->transfer_buffer_length = urb_size;
 	urb_in->context = line6pcm;

 	ret = usb_submit_urb(urb_in, GFP_ATOMIC);

 	if (ret == 0)
 		set_bit(index, &line6pcm->in.active_urbs);
 	else
 		dev_err(line6pcm->line6->ifcdev,
 			"URB in #%d submission failed (%d)\n", index, ret);

 	return 0;
 }

 /*
 	Submit all currently available capture URBs.
 	must be called in line6pcm->in.lock context
 */
 int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm)
 {
 	int ret = 0, i;

 	for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
 		ret = submit_audio_in_urb(line6pcm);
 		if (ret < 0)
 			break;
 	}

 	return ret;
 }

 /*
 	Copy data into ALSA capture buffer.
 */
 void line6_capture_copy(struct snd_line6_pcm *line6pcm, char *fbuf, int fsize)
 {
 	struct snd_pcm_substream *substream =
 	    get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	const int bytes_per_frame =
 		line6pcm->properties->bytes_per_channel *
 		line6pcm->properties->capture_hw.channels_max;
 	int frames = fsize / bytes_per_frame;

 	if (runtime == NULL)
 		return;

 	if (line6pcm->in.pos_done + frames > runtime->buffer_size) {
 		/*
 		   The transferred area goes over buffer boundary,
 		   copy two separate chunks.
 		 */
 		int len;

 		len = runtime->buffer_size - line6pcm->in.pos_done;

 		if (len > 0) {
 			memcpy(runtime->dma_area +
 			       line6pcm->in.pos_done * bytes_per_frame, fbuf,
 			       len * bytes_per_frame);
 			memcpy(runtime->dma_area, fbuf + len * bytes_per_frame,
 			       (frames - len) * bytes_per_frame);
 		} else {
 			/* this is somewhat paranoid */
 			dev_err(line6pcm->line6->ifcdev,
 				"driver bug: len = %d\n", len);
 		}
 	} else {
 		/* copy single chunk */
 		memcpy(runtime->dma_area +
 		       line6pcm->in.pos_done * bytes_per_frame, fbuf, fsize);
 	}

 	line6pcm->in.pos_done += frames;
 	if (line6pcm->in.pos_done >= runtime->buffer_size)
 		line6pcm->in.pos_done -= runtime->buffer_size;
 }

 void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
 {
 	struct snd_pcm_substream *substream =
 	    get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);

 	line6pcm->in.bytes += length;
 	if (line6pcm->in.bytes >= line6pcm->in.period) {
 		line6pcm->in.bytes %= line6pcm->in.period;
 		spin_unlock(&line6pcm->in.lock);
 		snd_pcm_period_elapsed(substream);
 		spin_lock(&line6pcm->in.lock);
 	}
 }

 /*
  * Callback for completed capture URB.
  */
 static void audio_in_callback(struct urb *urb)
 {
 	int i, index, length = 0, shutdown = 0;
 	unsigned long flags;

 	struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;

 	line6pcm->in.last_frame = urb->start_frame;

 	/* find index of URB */
 	for (index = 0; index < line6pcm->line6->iso_buffers; ++index)
 		if (urb == line6pcm->in.urbs[index])
 			break;

 	spin_lock_irqsave(&line6pcm->in.lock, flags);

 	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
 		char *fbuf;
 		int fsize;
 		struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];

 		if (fin->status == -EXDEV) {
 			shutdown = 1;
 			break;
 		}

 		fbuf = urb->transfer_buffer + fin->offset;
 		fsize = fin->actual_length;

 		if (fsize > line6pcm->max_packet_size_in) {
 			dev_err(line6pcm->line6->ifcdev,
 				"driver and/or device bug: packet too large (%d > %d)\n",
 				fsize, line6pcm->max_packet_size_in);
 		}

 		length += fsize;

 		BUILD_BUG_ON_MSG(LINE6_ISO_PACKETS != 1,
 			"The following code assumes LINE6_ISO_PACKETS == 1");
 		/* TODO:
 		 * Also, if iso_buffers != 2, the prev frame is almost random at
 		 * playback side.
 		 * This needs to be redesigned. It should be "stable", but we may
 		 * experience sync problems on such high-speed configs.
 		 */

 		line6pcm->prev_fbuf = fbuf;
 		line6pcm->prev_fsize = fsize /
 			(line6pcm->properties->bytes_per_channel *
 			line6pcm->properties->capture_hw.channels_max);

 		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
 		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running) &&
 		    fsize > 0)
 			line6_capture_copy(line6pcm, fbuf, fsize);
 	}

 	clear_bit(index, &line6pcm->in.active_urbs);

 	if (test_and_clear_bit(index, &line6pcm->in.unlink_urbs))
 		shutdown = 1;

 	if (!shutdown) {
 		submit_audio_in_urb(line6pcm);

 		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
 		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running))
 			line6_capture_check_period(line6pcm, length);
 	}

 	spin_unlock_irqrestore(&line6pcm->in.lock, flags);
 }

 /* open capture callback */
 static int snd_line6_capture_open(struct snd_pcm_substream *substream)
 {
 	int err;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

 	err = snd_pcm_hw_constraint_ratdens(runtime, 0,
 					    SNDRV_PCM_HW_PARAM_RATE,
 					    &line6pcm->properties->rates);
 	if (err < 0)
 		return err;

 	line6_pcm_acquire(line6pcm, LINE6_STREAM_CAPTURE_HELPER, false);

 	runtime->hw = line6pcm->properties->capture_hw;
 	return 0;
 }

 /* close capture callback */
 static int snd_line6_capture_close(struct snd_pcm_substream *substream)
 {
 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

 	line6_pcm_release(line6pcm, LINE6_STREAM_CAPTURE_HELPER);
 	return 0;
 }

 /* capture operators */
 const struct snd_pcm_ops snd_line6_capture_ops = {
 	.open = snd_line6_capture_open,
 	.close = snd_line6_capture_close,
 	.hw_params = snd_line6_hw_params,
 	.hw_free = snd_line6_hw_free,
 	.prepare = snd_line6_prepare,
 	.trigger = snd_line6_trigger,
 	.pointer = snd_line6_pointer,
 };

 int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
 {
 	struct usb_line6 *line6 = line6pcm->line6;
 	int i;

 	line6pcm->in.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
 				    GFP_KERNEL);
 	if (line6pcm->in.urbs == NULL)
 		return -ENOMEM;

 	/* create audio URBs and fill in constant values: */
 	for (i = 0; i < line6->iso_buffers; ++i) {
 		struct urb *urb;

 		/* URB for audio in: */
 		urb = line6pcm->in.urbs[i] =
 		    usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);

 		if (urb == NULL)
 			return -ENOMEM;

 		urb->dev = line6->usbdev;
 		urb->pipe =
 		    usb_rcvisocpipe(line6->usbdev,
 				    line6->properties->ep_audio_r &
 				    USB_ENDPOINT_NUMBER_MASK);
 		urb->transfer_flags = URB_ISO_ASAP;
 		urb->start_frame = -1;
 		urb->number_of_packets = LINE6_ISO_PACKETS;
 		urb->interval = LINE6_ISO_INTERVAL;
 		urb->error_count = 0;
 		urb->complete = audio_in_callback;
 		if (usb_urb_ep_type_check(urb))
 			return -EINVAL;
 	}

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Line 6 Linux USB driver
	*
	* Copyright (C) 2004-2010 Markus Grabner (line6@grabner-graz.at)
	*/

	#include <linux/slab.h>
	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>

	#include "capture.h"
	#include "driver.h"
	#include "pcm.h"

	/*
	Find a free URB and submit it.
	must be called in line6pcm->in.lock context
	*/
	static int submit_audio_in_urb(struct snd_line6_pcm *line6pcm)
	{
	int index;
	int i, urb_size;
	int ret;
	struct urb *urb_in;

	index = find_first_zero_bit(&line6pcm->in.active_urbs,
	line6pcm->line6->iso_buffers);

	if (index < 0 \|\| index >= line6pcm->line6->iso_buffers) {
	dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
	return -EINVAL;
	}

	urb_in = line6pcm->in.urbs[index];
	urb_size = 0;

	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
	struct usb_iso_packet_descriptor *fin =
	&urb_in->iso_frame_desc[i];
	fin->offset = urb_size;
	fin->length = line6pcm->max_packet_size_in;
	urb_size += line6pcm->max_packet_size_in;
	}

	urb_in->transfer_buffer =
	line6pcm->in.buffer +
	index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_in;
	urb_in->transfer_buffer_length = urb_size;
	urb_in->context = line6pcm;

	ret = usb_submit_urb(urb_in, GFP_ATOMIC);

	if (ret == 0)
	set_bit(index, &line6pcm->in.active_urbs);
	else
	dev_err(line6pcm->line6->ifcdev,
	"URB in #%d submission failed (%d)\n", index, ret);

	return 0;
	}

	/*
	Submit all currently available capture URBs.
	must be called in line6pcm->in.lock context
	*/
	int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm)
	{
	int ret = 0, i;

	for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
	ret = submit_audio_in_urb(line6pcm);
	if (ret < 0)
	break;
	}

	return ret;
	}

	/*
	Copy data into ALSA capture buffer.
	*/
	void line6_capture_copy(struct snd_line6_pcm line6pcm, char fbuf, int fsize)
	{
	struct snd_pcm_substream *substream =
	get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
	struct snd_pcm_runtime *runtime = substream->runtime;
	const int bytes_per_frame =
	line6pcm->properties->bytes_per_channel *
	line6pcm->properties->capture_hw.channels_max;
	int frames = fsize / bytes_per_frame;

	if (runtime == NULL)
	return;

	if (line6pcm->in.pos_done + frames > runtime->buffer_size) {
	/*
	The transferred area goes over buffer boundary,
	copy two separate chunks.
	*/
	int len;

	len = runtime->buffer_size - line6pcm->in.pos_done;

	if (len > 0) {
	memcpy(runtime->dma_area +
	line6pcm->in.pos_done * bytes_per_frame, fbuf,
	len * bytes_per_frame);
	memcpy(runtime->dma_area, fbuf + len * bytes_per_frame,
	(frames - len) * bytes_per_frame);
	} else {
	/* this is somewhat paranoid */
	dev_err(line6pcm->line6->ifcdev,
	"driver bug: len = %d\n", len);
	}
	} else {
	/* copy single chunk */
	memcpy(runtime->dma_area +
	line6pcm->in.pos_done * bytes_per_frame, fbuf, fsize);
	}

	line6pcm->in.pos_done += frames;
	if (line6pcm->in.pos_done >= runtime->buffer_size)
	line6pcm->in.pos_done -= runtime->buffer_size;
	}

	void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
	{
	struct snd_pcm_substream *substream =
	get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);

	line6pcm->in.bytes += length;
	if (line6pcm->in.bytes >= line6pcm->in.period) {
	line6pcm->in.bytes %= line6pcm->in.period;
	spin_unlock(&line6pcm->in.lock);
	snd_pcm_period_elapsed(substream);
	spin_lock(&line6pcm->in.lock);
	}
	}

	/*
	* Callback for completed capture URB.
	*/
	static void audio_in_callback(struct urb *urb)
	{
	int i, index, length = 0, shutdown = 0;
	unsigned long flags;

	struct snd_line6_pcm line6pcm = (struct snd_line6_pcm )urb->context;

	line6pcm->in.last_frame = urb->start_frame;

	/* find index of URB */
	for (index = 0; index < line6pcm->line6->iso_buffers; ++index)
	if (urb == line6pcm->in.urbs[index])
	break;

	spin_lock_irqsave(&line6pcm->in.lock, flags);

	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
	char *fbuf;
	int fsize;
	struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];

	if (fin->status == -EXDEV) {
	shutdown = 1;
	break;
	}

	fbuf = urb->transfer_buffer + fin->offset;
	fsize = fin->actual_length;

	if (fsize > line6pcm->max_packet_size_in) {
	dev_err(line6pcm->line6->ifcdev,
	"driver and/or device bug: packet too large (%d > %d)\n",
	fsize, line6pcm->max_packet_size_in);
	}

	length += fsize;

	BUILD_BUG_ON_MSG(LINE6_ISO_PACKETS != 1,
	"The following code assumes LINE6_ISO_PACKETS == 1");
	/* TODO:
	* Also, if iso_buffers != 2, the prev frame is almost random at
	* playback side.
	* This needs to be redesigned. It should be "stable", but we may
	* experience sync problems on such high-speed configs.
	*/

	line6pcm->prev_fbuf = fbuf;
	line6pcm->prev_fsize = fsize /
	(line6pcm->properties->bytes_per_channel *
	line6pcm->properties->capture_hw.channels_max);

	if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
	test_bit(LINE6_STREAM_PCM, &line6pcm->in.running) &&
	fsize > 0)
	line6_capture_copy(line6pcm, fbuf, fsize);
	}

	clear_bit(index, &line6pcm->in.active_urbs);

	if (test_and_clear_bit(index, &line6pcm->in.unlink_urbs))
	shutdown = 1;

	if (!shutdown) {
	submit_audio_in_urb(line6pcm);

	if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
	test_bit(LINE6_STREAM_PCM, &line6pcm->in.running))
	line6_capture_check_period(line6pcm, length);
	}

	spin_unlock_irqrestore(&line6pcm->in.lock, flags);
	}

	/* open capture callback */
	static int snd_line6_capture_open(struct snd_pcm_substream *substream)
	{
	int err;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	err = snd_pcm_hw_constraint_ratdens(runtime, 0,
	SNDRV_PCM_HW_PARAM_RATE,
	&line6pcm->properties->rates);
	if (err < 0)
	return err;

	line6_pcm_acquire(line6pcm, LINE6_STREAM_CAPTURE_HELPER, false);

	runtime->hw = line6pcm->properties->capture_hw;
	return 0;
	}

	/* close capture callback */
	static int snd_line6_capture_close(struct snd_pcm_substream *substream)
	{
	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	line6_pcm_release(line6pcm, LINE6_STREAM_CAPTURE_HELPER);
	return 0;
	}

	/* capture operators */
	const struct snd_pcm_ops snd_line6_capture_ops = {
	.open = snd_line6_capture_open,
	.close = snd_line6_capture_close,
	.hw_params = snd_line6_hw_params,
	.hw_free = snd_line6_hw_free,
	.prepare = snd_line6_prepare,
	.trigger = snd_line6_trigger,
	.pointer = snd_line6_pointer,
	};

	int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
	{
	struct usb_line6 *line6 = line6pcm->line6;
	int i;

	line6pcm->in.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
	GFP_KERNEL);
	if (line6pcm->in.urbs == NULL)
	return -ENOMEM;

	/* create audio URBs and fill in constant values: */
	for (i = 0; i < line6->iso_buffers; ++i) {
	struct urb *urb;

	/* URB for audio in: */
	urb = line6pcm->in.urbs[i] =
	usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);

	if (urb == NULL)
	return -ENOMEM;

	urb->dev = line6->usbdev;
	urb->pipe =
	usb_rcvisocpipe(line6->usbdev,
	line6->properties->ep_audio_r &
	USB_ENDPOINT_NUMBER_MASK);
	urb->transfer_flags = URB_ISO_ASAP;
	urb->start_frame = -1;
	urb->number_of_packets = LINE6_ISO_PACKETS;
	urb->interval = LINE6_ISO_INTERVAL;
	urb->error_count = 0;
	urb->complete = audio_in_callback;
	if (usb_urb_ep_type_check(urb))
	return -EINVAL;
	}

	return 0;
	}