1 files changed, 439 insertions, 0 deletions

diff --git a/sound/usb/line6/playback.c b/sound/usb/line6/playback.c
new file mode 100644
index 0000000000..8233c61e23
--- /dev/null
+++ b/sound/usb/line6/playback.c
@@ -0,0 +1,439 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Line 6 Linux USB driver
+ *
+ * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.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"
+#include "playback.h"
+
+/*
+	Software stereo volume control.
+*/
+static void change_volume(struct urb *urb_out, int volume[],
+			  int bytes_per_frame)
+{
+	int chn = 0;
+
+	if (volume[0] == 256 && volume[1] == 256)
+		return;		/* maximum volume - no change */
+
+	if (bytes_per_frame == 4) {
+		__le16 *p, *buf_end;
+
+		p = (__le16 *)urb_out->transfer_buffer;
+		buf_end = p + urb_out->transfer_buffer_length / sizeof(*p);
+
+		for (; p < buf_end; ++p) {
+			short pv = le16_to_cpu(*p);
+			int val = (pv * volume[chn & 1]) >> 8;
+			pv = clamp(val, -0x8000, 0x7fff);
+			*p = cpu_to_le16(pv);
+			++chn;
+		}
+	} else if (bytes_per_frame == 6) {
+		unsigned char *p, *buf_end;
+
+		p = (unsigned char *)urb_out->transfer_buffer;
+		buf_end = p + urb_out->transfer_buffer_length;
+
+		for (; p < buf_end; p += 3) {
+			int val;
+
+			val = p[0] + (p[1] << 8) + ((signed char)p[2] << 16);
+			val = (val * volume[chn & 1]) >> 8;
+			val = clamp(val, -0x800000, 0x7fffff);
+			p[0] = val;
+			p[1] = val >> 8;
+			p[2] = val >> 16;
+			++chn;
+		}
+	}
+}
+
+/*
+	Create signal for impulse response test.
+*/
+static void create_impulse_test_signal(struct snd_line6_pcm *line6pcm,
+				       struct urb *urb_out, int bytes_per_frame)
+{
+	int frames = urb_out->transfer_buffer_length / bytes_per_frame;
+
+	if (bytes_per_frame == 4) {
+		int i;
+		short *pi = (short *)line6pcm->prev_fbuf;
+		short *po = (short *)urb_out->transfer_buffer;
+
+		for (i = 0; i < frames; ++i) {
+			po[0] = pi[0];
+			po[1] = 0;
+			pi += 2;
+			po += 2;
+		}
+	} else if (bytes_per_frame == 6) {
+		int i, j;
+		unsigned char *pi = line6pcm->prev_fbuf;
+		unsigned char *po = urb_out->transfer_buffer;
+
+		for (i = 0; i < frames; ++i) {
+			for (j = 0; j < bytes_per_frame / 2; ++j)
+				po[j] = pi[j];
+
+			for (; j < bytes_per_frame; ++j)
+				po[j] = 0;
+
+			pi += bytes_per_frame;
+			po += bytes_per_frame;
+		}
+	}
+	if (--line6pcm->impulse_count <= 0) {
+		((unsigned char *)(urb_out->transfer_buffer))[bytes_per_frame -
+							      1] =
+		    line6pcm->impulse_volume;
+		line6pcm->impulse_count = line6pcm->impulse_period;
+	}
+}
+
+/*
+	Add signal to buffer for software monitoring.
+*/
+static void add_monitor_signal(struct urb *urb_out, unsigned char *signal,
+			       int volume, int bytes_per_frame)
+{
+	if (volume == 0)
+		return;		/* zero volume - no change */
+
+	if (bytes_per_frame == 4) {
+		__le16 *pi, *po, *buf_end;
+
+		pi = (__le16 *)signal;
+		po = (__le16 *)urb_out->transfer_buffer;
+		buf_end = po + urb_out->transfer_buffer_length / sizeof(*po);
+
+		for (; po < buf_end; ++pi, ++po) {
+			short pov = le16_to_cpu(*po);
+			short piv = le16_to_cpu(*pi);
+			int val = pov + ((piv * volume) >> 8);
+			pov = clamp(val, -0x8000, 0x7fff);
+			*po = cpu_to_le16(pov);
+		}
+	}
+
+	/*
+	   We don't need to handle devices with 6 bytes per frame here
+	   since they all support hardware monitoring.
+	 */
+}
+
+/*
+	Find a free URB, prepare audio data, and submit URB.
+	must be called in line6pcm->out.lock context
+*/
+static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
+{
+	int index;
+	int i, urb_size, urb_frames;
+	int ret;
+	const int bytes_per_frame =
+		line6pcm->properties->bytes_per_channel *
+		line6pcm->properties->playback_hw.channels_max;
+	const int frame_increment =
+		line6pcm->properties->rates.rats[0].num_min;
+	const int frame_factor =
+		line6pcm->properties->rates.rats[0].den *
+		(line6pcm->line6->intervals_per_second / LINE6_ISO_INTERVAL);
+	struct urb *urb_out;
+
+	index = find_first_zero_bit(&line6pcm->out.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_out = line6pcm->out.urbs[index];
+	urb_size = 0;
+
+	/* TODO: this may not work for LINE6_ISO_PACKETS != 1 */
+	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
+		/* compute frame size for given sampling rate */
+		int fsize = 0;
+		struct usb_iso_packet_descriptor *fout =
+		    &urb_out->iso_frame_desc[i];
+
+		fsize = line6pcm->prev_fsize;
+		if (fsize == 0) {
+			int n;
+
+			line6pcm->out.count += frame_increment;
+			n = line6pcm->out.count / frame_factor;
+			line6pcm->out.count -= n * frame_factor;
+			fsize = n;
+		}
+
+		fsize *= bytes_per_frame;
+
+		fout->offset = urb_size;
+		fout->length = fsize;
+		urb_size += fsize;
+	}
+
+	if (urb_size == 0) {
+		/* can't determine URB size */
+		dev_err(line6pcm->line6->ifcdev, "driver bug: urb_size = 0\n");
+		return -EINVAL;
+	}
+
+	urb_frames = urb_size / bytes_per_frame;
+	urb_out->transfer_buffer =
+	    line6pcm->out.buffer +
+	    index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_out;
+	urb_out->transfer_buffer_length = urb_size;
+	urb_out->context = line6pcm;
+
+	if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running) &&
+	    !test_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags)) {
+		struct snd_pcm_runtime *runtime =
+		    get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK)->runtime;
+
+		if (line6pcm->out.pos + urb_frames > runtime->buffer_size) {
+			/*
+			   The transferred area goes over buffer boundary,
+			   copy the data to the temp buffer.
+			 */
+			int len;
+
+			len = runtime->buffer_size - line6pcm->out.pos;
+
+			if (len > 0) {
+				memcpy(urb_out->transfer_buffer,
+				       runtime->dma_area +
+				       line6pcm->out.pos * bytes_per_frame,
+				       len * bytes_per_frame);
+				memcpy(urb_out->transfer_buffer +
+				       len * bytes_per_frame, runtime->dma_area,
+				       (urb_frames - len) * bytes_per_frame);
+			} else
+				dev_err(line6pcm->line6->ifcdev, "driver bug: len = %d\n",
+					len);
+		} else {
+			memcpy(urb_out->transfer_buffer,
+			       runtime->dma_area +
+			       line6pcm->out.pos * bytes_per_frame,
+			       urb_out->transfer_buffer_length);
+		}
+
+		line6pcm->out.pos += urb_frames;
+		if (line6pcm->out.pos >= runtime->buffer_size)
+			line6pcm->out.pos -= runtime->buffer_size;
+
+		change_volume(urb_out, line6pcm->volume_playback,
+			      bytes_per_frame);
+	} else {
+		memset(urb_out->transfer_buffer, 0,
+		       urb_out->transfer_buffer_length);
+	}
+
+	spin_lock_nested(&line6pcm->in.lock, SINGLE_DEPTH_NESTING);
+	if (line6pcm->prev_fbuf) {
+		if (test_bit(LINE6_STREAM_IMPULSE, &line6pcm->out.running)) {
+			create_impulse_test_signal(line6pcm, urb_out,
+						   bytes_per_frame);
+			if (test_bit(LINE6_STREAM_PCM, &line6pcm->in.running)) {
+				line6_capture_copy(line6pcm,
+						   urb_out->transfer_buffer,
+						   urb_out->
+						   transfer_buffer_length);
+				line6_capture_check_period(line6pcm,
+					urb_out->transfer_buffer_length);
+			}
+		} else {
+			if (!(line6pcm->line6->properties->capabilities & LINE6_CAP_HWMON)
+			    && line6pcm->out.running && line6pcm->in.running)
+				add_monitor_signal(urb_out, line6pcm->prev_fbuf,
+						   line6pcm->volume_monitor,
+						   bytes_per_frame);
+		}
+		line6pcm->prev_fbuf = NULL;
+		line6pcm->prev_fsize = 0;
+	}
+	spin_unlock(&line6pcm->in.lock);
+
+	ret = usb_submit_urb(urb_out, GFP_ATOMIC);
+
+	if (ret == 0)
+		set_bit(index, &line6pcm->out.active_urbs);
+	else
+		dev_err(line6pcm->line6->ifcdev,
+			"URB out #%d submission failed (%d)\n", index, ret);
+
+	return 0;
+}
+
+/*
+	Submit all currently available playback URBs.
+	must be called in line6pcm->out.lock context
+ */
+int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm)
+{
+	int ret = 0, i;
+
+	for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
+		ret = submit_audio_out_urb(line6pcm);
+		if (ret < 0)
+			break;
+	}
+
+	return ret;
+}
+
+/*
+	Callback for completed playback URB.
+*/
+static void audio_out_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;
+	struct snd_pcm_substream *substream =
+	    get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK);
+	const int bytes_per_frame =
+		line6pcm->properties->bytes_per_channel *
+		line6pcm->properties->playback_hw.channels_max;
+
+#if USE_CLEAR_BUFFER_WORKAROUND
+	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
+#endif
+
+	line6pcm->out.last_frame = urb->start_frame;
+
+	/* find index of URB */
+	for (index = 0; index < line6pcm->line6->iso_buffers; index++)
+		if (urb == line6pcm->out.urbs[index])
+			break;
+
+	if (index >= line6pcm->line6->iso_buffers)
+		return;		/* URB has been unlinked asynchronously */
+
+	for (i = 0; i < LINE6_ISO_PACKETS; i++)
+		length += urb->iso_frame_desc[i].length;
+
+	spin_lock_irqsave(&line6pcm->out.lock, flags);
+
+	if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running)) {
+		struct snd_pcm_runtime *runtime = substream->runtime;
+
+		line6pcm->out.pos_done +=
+		    length / bytes_per_frame;
+
+		if (line6pcm->out.pos_done >= runtime->buffer_size)
+			line6pcm->out.pos_done -= runtime->buffer_size;
+	}
+
+	clear_bit(index, &line6pcm->out.active_urbs);
+
+	for (i = 0; i < LINE6_ISO_PACKETS; i++)
+		if (urb->iso_frame_desc[i].status == -EXDEV) {
+			shutdown = 1;
+			break;
+		}
+
+	if (test_and_clear_bit(index, &line6pcm->out.unlink_urbs))
+		shutdown = 1;
+
+	if (!shutdown) {
+		submit_audio_out_urb(line6pcm);
+
+		if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running)) {
+			line6pcm->out.bytes += length;
+			if (line6pcm->out.bytes >= line6pcm->out.period) {
+				line6pcm->out.bytes %= line6pcm->out.period;
+				spin_unlock(&line6pcm->out.lock);
+				snd_pcm_period_elapsed(substream);
+				spin_lock(&line6pcm->out.lock);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&line6pcm->out.lock, flags);
+}
+
+/* open playback callback */
+static int snd_line6_playback_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;
+
+	runtime->hw = line6pcm->properties->playback_hw;
+	return 0;
+}
+
+/* close playback callback */
+static int snd_line6_playback_close(struct snd_pcm_substream *substream)
+{
+	return 0;
+}
+
+/* playback operators */
+const struct snd_pcm_ops snd_line6_playback_ops = {
+	.open = snd_line6_playback_open,
+	.close = snd_line6_playback_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_out_urbs(struct snd_line6_pcm *line6pcm)
+{
+	struct usb_line6 *line6 = line6pcm->line6;
+	int i;
+
+	line6pcm->out.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
+				     GFP_KERNEL);
+	if (line6pcm->out.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 out: */
+		urb = line6pcm->out.urbs[i] =
+		    usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
+
+		if (urb == NULL)
+			return -ENOMEM;
+
+		urb->dev = line6->usbdev;
+		urb->pipe =
+		    usb_sndisocpipe(line6->usbdev,
+				    line6->properties->ep_audio_w &
+				    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_out_callback;
+		if (usb_urb_ep_type_check(urb))
+			return -EINVAL;
+	}
+
+	return 0;
+}