summaryrefslogtreecommitdiffstats
path: root/drivers/media/usb/em28xx/em28xx-audio.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/media/usb/em28xx/em28xx-audio.c')
-rw-r--r--drivers/media/usb/em28xx/em28xx-audio.c975
1 files changed, 975 insertions, 0 deletions
diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c
new file mode 100644
index 000000000..ce1b0d9e0
--- /dev/null
+++ b/drivers/media/usb/em28xx/em28xx-audio.c
@@ -0,0 +1,975 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Empiatech em28x1 audio extension
+//
+// Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
+//
+// Copyright (C) 2007-2016 Mauro Carvalho Chehab
+// - Port to work with the in-kernel driver
+// - Cleanups, fixes, alsa-controls, etc.
+//
+// This driver is based on my previous au600 usb pstn audio driver
+// and inherits all the copyrights
+
+#include "em28xx.h"
+
+#include <linux/kernel.h>
+#include <linux/usb.h>
+#include <linux/init.h>
+#include <linux/sound.h>
+#include <linux/spinlock.h>
+#include <linux/soundcard.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/info.h>
+#include <sound/initval.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+#include <sound/ac97_codec.h>
+#include <media/v4l2-common.h>
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "activates debug info");
+
+#define EM28XX_MAX_AUDIO_BUFS 5
+#define EM28XX_MIN_AUDIO_PACKETS 64
+
+#define dprintk(fmt, arg...) do { \
+ if (debug) \
+ dev_printk(KERN_DEBUG, &dev->intf->dev, \
+ "video: %s: " fmt, __func__, ## arg); \
+} while (0)
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
+
+static int em28xx_deinit_isoc_audio(struct em28xx *dev)
+{
+ int i;
+
+ dprintk("Stopping isoc\n");
+ for (i = 0; i < dev->adev.num_urb; i++) {
+ struct urb *urb = dev->adev.urb[i];
+
+ if (!irqs_disabled())
+ usb_kill_urb(urb);
+ else
+ usb_unlink_urb(urb);
+ }
+
+ return 0;
+}
+
+static void em28xx_audio_isocirq(struct urb *urb)
+{
+ struct em28xx *dev = urb->context;
+ int i;
+ unsigned int oldptr;
+ int period_elapsed = 0;
+ int status;
+ unsigned char *cp;
+ unsigned int stride;
+ struct snd_pcm_substream *substream;
+ struct snd_pcm_runtime *runtime;
+
+ if (dev->disconnected) {
+ dprintk("device disconnected while streaming. URB status=%d.\n",
+ urb->status);
+ atomic_set(&dev->adev.stream_started, 0);
+ return;
+ }
+
+ switch (urb->status) {
+ case 0: /* success */
+ case -ETIMEDOUT: /* NAK */
+ break;
+ case -ECONNRESET: /* kill */
+ case -ENOENT:
+ case -ESHUTDOWN:
+ return;
+ default: /* error */
+ dprintk("urb completion error %d.\n", urb->status);
+ break;
+ }
+
+ if (atomic_read(&dev->adev.stream_started) == 0)
+ return;
+
+ if (dev->adev.capture_pcm_substream) {
+ substream = dev->adev.capture_pcm_substream;
+ runtime = substream->runtime;
+ stride = runtime->frame_bits >> 3;
+
+ for (i = 0; i < urb->number_of_packets; i++) {
+ unsigned long flags;
+ int length =
+ urb->iso_frame_desc[i].actual_length / stride;
+ cp = (unsigned char *)urb->transfer_buffer +
+ urb->iso_frame_desc[i].offset;
+
+ if (!length)
+ continue;
+
+ oldptr = dev->adev.hwptr_done_capture;
+ if (oldptr + length >= runtime->buffer_size) {
+ unsigned int cnt =
+ runtime->buffer_size - oldptr;
+ memcpy(runtime->dma_area + oldptr * stride, cp,
+ cnt * stride);
+ memcpy(runtime->dma_area, cp + cnt * stride,
+ length * stride - cnt * stride);
+ } else {
+ memcpy(runtime->dma_area + oldptr * stride, cp,
+ length * stride);
+ }
+
+ snd_pcm_stream_lock_irqsave(substream, flags);
+
+ dev->adev.hwptr_done_capture += length;
+ if (dev->adev.hwptr_done_capture >=
+ runtime->buffer_size)
+ dev->adev.hwptr_done_capture -=
+ runtime->buffer_size;
+
+ dev->adev.capture_transfer_done += length;
+ if (dev->adev.capture_transfer_done >=
+ runtime->period_size) {
+ dev->adev.capture_transfer_done -=
+ runtime->period_size;
+ period_elapsed = 1;
+ }
+
+ snd_pcm_stream_unlock_irqrestore(substream, flags);
+ }
+ if (period_elapsed)
+ snd_pcm_period_elapsed(substream);
+ }
+ urb->status = 0;
+
+ status = usb_submit_urb(urb, GFP_ATOMIC);
+ if (status < 0)
+ dev_err(&dev->intf->dev,
+ "resubmit of audio urb failed (error=%i)\n",
+ status);
+}
+
+static int em28xx_init_audio_isoc(struct em28xx *dev)
+{
+ int i, err;
+
+ dprintk("Starting isoc transfers\n");
+
+ /* Start streaming */
+ for (i = 0; i < dev->adev.num_urb; i++) {
+ memset(dev->adev.transfer_buffer[i], 0x80,
+ dev->adev.urb[i]->transfer_buffer_length);
+
+ err = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
+ if (err) {
+ dev_err(&dev->intf->dev,
+ "submit of audio urb failed (error=%i)\n",
+ err);
+ em28xx_deinit_isoc_audio(dev);
+ atomic_set(&dev->adev.stream_started, 0);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+static const struct snd_pcm_hardware snd_em28xx_hw_capture = {
+ .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
+ SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_INTERLEAVED |
+ SNDRV_PCM_INFO_BATCH |
+ SNDRV_PCM_INFO_MMAP_VALID,
+
+ .formats = SNDRV_PCM_FMTBIT_S16_LE,
+
+ .rates = SNDRV_PCM_RATE_48000,
+
+ .rate_min = 48000,
+ .rate_max = 48000,
+ .channels_min = 2,
+ .channels_max = 2,
+ .buffer_bytes_max = 62720 * 8, /* just about the value in usbaudio.c */
+
+ /*
+ * The period is 12.288 bytes. Allow a 10% of variation along its
+ * value, in order to avoid overruns/underruns due to some clock
+ * drift.
+ *
+ * FIXME: This period assumes 64 packets, and a 48000 PCM rate.
+ * Calculate it dynamically.
+ */
+ .period_bytes_min = 11059,
+ .period_bytes_max = 13516,
+
+ .periods_min = 2,
+ .periods_max = 98, /* 12544, */
+};
+
+static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
+{
+ struct em28xx *dev = snd_pcm_substream_chip(substream);
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ int nonblock, ret = 0;
+
+ if (!dev) {
+ pr_err("em28xx-audio: BUG: em28xx can't find device struct. Can't proceed with open\n");
+ return -ENODEV;
+ }
+
+ if (dev->disconnected)
+ return -ENODEV;
+
+ dprintk("opening device and trying to acquire exclusive lock\n");
+
+ nonblock = !!(substream->f_flags & O_NONBLOCK);
+ if (nonblock) {
+ if (!mutex_trylock(&dev->lock))
+ return -EAGAIN;
+ } else {
+ mutex_lock(&dev->lock);
+ }
+
+ runtime->hw = snd_em28xx_hw_capture;
+
+ if (dev->adev.users == 0) {
+ if (!dev->alt || dev->is_audio_only) {
+ struct usb_device *udev;
+
+ udev = interface_to_usbdev(dev->intf);
+
+ if (dev->is_audio_only)
+ /* audio is on a separate interface */
+ dev->alt = 1;
+ else
+ /* audio is on the same interface as video */
+ dev->alt = 7;
+ /*
+ * FIXME: The intention seems to be to select
+ * the alt setting with the largest
+ * wMaxPacketSize for the video endpoint.
+ * At least dev->alt should be used instead, but
+ * we should probably not touch it at all if it
+ * is already >0, because wMaxPacketSize of the
+ * audio endpoints seems to be the same for all.
+ */
+ dprintk("changing alternate number on interface %d to %d\n",
+ dev->ifnum, dev->alt);
+ usb_set_interface(udev, dev->ifnum, dev->alt);
+ }
+
+ /* Sets volume, mute, etc */
+ dev->mute = 0;
+ ret = em28xx_audio_analog_set(dev);
+ if (ret < 0)
+ goto err;
+ }
+
+ kref_get(&dev->ref);
+ dev->adev.users++;
+ mutex_unlock(&dev->lock);
+
+ /* Dynamically adjust the period size */
+ snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
+ snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
+ dev->adev.period * 95 / 100,
+ dev->adev.period * 105 / 100);
+
+ dev->adev.capture_pcm_substream = substream;
+
+ return 0;
+err:
+ mutex_unlock(&dev->lock);
+
+ dev_err(&dev->intf->dev,
+ "Error while configuring em28xx mixer\n");
+ return ret;
+}
+
+static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
+{
+ struct em28xx *dev = snd_pcm_substream_chip(substream);
+
+ dprintk("closing device\n");
+
+ dev->mute = 1;
+ mutex_lock(&dev->lock);
+ dev->adev.users--;
+ if (atomic_read(&dev->adev.stream_started) > 0) {
+ atomic_set(&dev->adev.stream_started, 0);
+ schedule_work(&dev->adev.wq_trigger);
+ }
+
+ em28xx_audio_analog_set(dev);
+ mutex_unlock(&dev->lock);
+ kref_put(&dev->ref, em28xx_free_device);
+
+ return 0;
+}
+
+static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
+{
+ struct em28xx *dev = snd_pcm_substream_chip(substream);
+
+ if (dev->disconnected)
+ return -ENODEV;
+
+ dev->adev.hwptr_done_capture = 0;
+ dev->adev.capture_transfer_done = 0;
+
+ return 0;
+}
+
+static void audio_trigger(struct work_struct *work)
+{
+ struct em28xx_audio *adev =
+ container_of(work, struct em28xx_audio, wq_trigger);
+ struct em28xx *dev = container_of(adev, struct em28xx, adev);
+
+ if (atomic_read(&adev->stream_started)) {
+ dprintk("starting capture");
+ em28xx_init_audio_isoc(dev);
+ } else {
+ dprintk("stopping capture");
+ em28xx_deinit_isoc_audio(dev);
+ }
+}
+
+static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
+ int cmd)
+{
+ struct em28xx *dev = snd_pcm_substream_chip(substream);
+ int retval = 0;
+
+ if (dev->disconnected)
+ return -ENODEV;
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_START:
+ atomic_set(&dev->adev.stream_started, 1);
+ break;
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_STOP:
+ atomic_set(&dev->adev.stream_started, 0);
+ break;
+ default:
+ retval = -EINVAL;
+ }
+ schedule_work(&dev->adev.wq_trigger);
+ return retval;
+}
+
+static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
+ *substream)
+{
+ unsigned long flags;
+ struct em28xx *dev;
+ snd_pcm_uframes_t hwptr_done;
+
+ dev = snd_pcm_substream_chip(substream);
+ if (dev->disconnected)
+ return SNDRV_PCM_POS_XRUN;
+
+ spin_lock_irqsave(&dev->adev.slock, flags);
+ hwptr_done = dev->adev.hwptr_done_capture;
+ spin_unlock_irqrestore(&dev->adev.slock, flags);
+
+ return hwptr_done;
+}
+
+/*
+ * AC97 volume control support
+ */
+static int em28xx_vol_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *info)
+{
+ struct em28xx *dev = snd_kcontrol_chip(kcontrol);
+
+ if (dev->disconnected)
+ return -ENODEV;
+
+ info->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ info->count = 2;
+ info->value.integer.min = 0;
+ info->value.integer.max = 0x1f;
+
+ return 0;
+}
+
+static int em28xx_vol_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *value)
+{
+ struct em28xx *dev = snd_kcontrol_chip(kcontrol);
+ struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
+ u16 val = (0x1f - (value->value.integer.value[0] & 0x1f)) |
+ (0x1f - (value->value.integer.value[1] & 0x1f)) << 8;
+ int nonblock = 0;
+ int rc;
+
+ if (dev->disconnected)
+ return -ENODEV;
+
+ if (substream)
+ nonblock = !!(substream->f_flags & O_NONBLOCK);
+ if (nonblock) {
+ if (!mutex_trylock(&dev->lock))
+ return -EAGAIN;
+ } else {
+ mutex_lock(&dev->lock);
+ }
+ rc = em28xx_read_ac97(dev, kcontrol->private_value);
+ if (rc < 0)
+ goto err;
+
+ val |= rc & 0x8000; /* Preserve the mute flag */
+
+ rc = em28xx_write_ac97(dev, kcontrol->private_value, val);
+ if (rc < 0)
+ goto err;
+
+ dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
+ (val & 0x8000) ? "muted " : "",
+ 0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
+ val, (int)kcontrol->private_value);
+
+err:
+ mutex_unlock(&dev->lock);
+ return rc;
+}
+
+static int em28xx_vol_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *value)
+{
+ struct em28xx *dev = snd_kcontrol_chip(kcontrol);
+ struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
+ int nonblock = 0;
+ int val;
+
+ if (dev->disconnected)
+ return -ENODEV;
+
+ if (substream)
+ nonblock = !!(substream->f_flags & O_NONBLOCK);
+ if (nonblock) {
+ if (!mutex_trylock(&dev->lock))
+ return -EAGAIN;
+ } else {
+ mutex_lock(&dev->lock);
+ }
+ val = em28xx_read_ac97(dev, kcontrol->private_value);
+ mutex_unlock(&dev->lock);
+ if (val < 0)
+ return val;
+
+ dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
+ (val & 0x8000) ? "muted " : "",
+ 0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
+ val, (int)kcontrol->private_value);
+
+ value->value.integer.value[0] = 0x1f - (val & 0x1f);
+ value->value.integer.value[1] = 0x1f - ((val >> 8) & 0x1f);
+
+ return 0;
+}
+
+static int em28xx_vol_put_mute(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *value)
+{
+ struct em28xx *dev = snd_kcontrol_chip(kcontrol);
+ u16 val = value->value.integer.value[0];
+ struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
+ int nonblock = 0;
+ int rc;
+
+ if (dev->disconnected)
+ return -ENODEV;
+
+ if (substream)
+ nonblock = !!(substream->f_flags & O_NONBLOCK);
+ if (nonblock) {
+ if (!mutex_trylock(&dev->lock))
+ return -EAGAIN;
+ } else {
+ mutex_lock(&dev->lock);
+ }
+ rc = em28xx_read_ac97(dev, kcontrol->private_value);
+ if (rc < 0)
+ goto err;
+
+ if (val)
+ rc &= 0x1f1f;
+ else
+ rc |= 0x8000;
+
+ rc = em28xx_write_ac97(dev, kcontrol->private_value, rc);
+ if (rc < 0)
+ goto err;
+
+ dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
+ (val & 0x8000) ? "muted " : "",
+ 0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
+ val, (int)kcontrol->private_value);
+
+err:
+ mutex_unlock(&dev->lock);
+ return rc;
+}
+
+static int em28xx_vol_get_mute(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *value)
+{
+ struct em28xx *dev = snd_kcontrol_chip(kcontrol);
+ struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
+ int nonblock = 0;
+ int val;
+
+ if (dev->disconnected)
+ return -ENODEV;
+
+ if (substream)
+ nonblock = !!(substream->f_flags & O_NONBLOCK);
+ if (nonblock) {
+ if (!mutex_trylock(&dev->lock))
+ return -EAGAIN;
+ } else {
+ mutex_lock(&dev->lock);
+ }
+ val = em28xx_read_ac97(dev, kcontrol->private_value);
+ mutex_unlock(&dev->lock);
+ if (val < 0)
+ return val;
+
+ if (val & 0x8000)
+ value->value.integer.value[0] = 0;
+ else
+ value->value.integer.value[0] = 1;
+
+ dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
+ (val & 0x8000) ? "muted " : "",
+ 0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
+ val, (int)kcontrol->private_value);
+
+ return 0;
+}
+
+static const DECLARE_TLV_DB_SCALE(em28xx_db_scale, -3450, 150, 0);
+
+static int em28xx_cvol_new(struct snd_card *card, struct em28xx *dev,
+ char *name, int id)
+{
+ int err;
+ char ctl_name[44];
+ struct snd_kcontrol *kctl;
+ struct snd_kcontrol_new tmp;
+
+ memset(&tmp, 0, sizeof(tmp));
+ tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+ tmp.private_value = id;
+ tmp.name = ctl_name;
+
+ /* Add Mute Control */
+ sprintf(ctl_name, "%s Switch", name);
+ tmp.get = em28xx_vol_get_mute;
+ tmp.put = em28xx_vol_put_mute;
+ tmp.info = snd_ctl_boolean_mono_info;
+ kctl = snd_ctl_new1(&tmp, dev);
+ err = snd_ctl_add(card, kctl);
+ if (err < 0)
+ return err;
+ dprintk("Added control %s for ac97 volume control 0x%04x\n",
+ ctl_name, id);
+
+ memset(&tmp, 0, sizeof(tmp));
+ tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+ tmp.private_value = id;
+ tmp.name = ctl_name;
+
+ /* Add Volume Control */
+ sprintf(ctl_name, "%s Volume", name);
+ tmp.get = em28xx_vol_get;
+ tmp.put = em28xx_vol_put;
+ tmp.info = em28xx_vol_info;
+ tmp.tlv.p = em28xx_db_scale;
+ kctl = snd_ctl_new1(&tmp, dev);
+ err = snd_ctl_add(card, kctl);
+ if (err < 0)
+ return err;
+ dprintk("Added control %s for ac97 volume control 0x%04x\n",
+ ctl_name, id);
+
+ return 0;
+}
+
+/*
+ * register/unregister code and data
+ */
+static const struct snd_pcm_ops snd_em28xx_pcm_capture = {
+ .open = snd_em28xx_capture_open,
+ .close = snd_em28xx_pcm_close,
+ .prepare = snd_em28xx_prepare,
+ .trigger = snd_em28xx_capture_trigger,
+ .pointer = snd_em28xx_capture_pointer,
+};
+
+static void em28xx_audio_free_urb(struct em28xx *dev)
+{
+ struct usb_device *udev = interface_to_usbdev(dev->intf);
+ int i;
+
+ for (i = 0; i < dev->adev.num_urb; i++) {
+ struct urb *urb = dev->adev.urb[i];
+
+ if (!urb)
+ continue;
+
+ usb_free_coherent(udev, urb->transfer_buffer_length,
+ dev->adev.transfer_buffer[i],
+ urb->transfer_dma);
+
+ usb_free_urb(urb);
+ }
+ kfree(dev->adev.urb);
+ kfree(dev->adev.transfer_buffer);
+ dev->adev.num_urb = 0;
+}
+
+/* high bandwidth multiplier, as encoded in highspeed endpoint descriptors */
+static int em28xx_audio_ep_packet_size(struct usb_device *udev,
+ struct usb_endpoint_descriptor *e)
+{
+ int size = le16_to_cpu(e->wMaxPacketSize);
+
+ if (udev->speed == USB_SPEED_HIGH)
+ return (size & 0x7ff) * (1 + (((size) >> 11) & 0x03));
+
+ return size & 0x7ff;
+}
+
+static int em28xx_audio_urb_init(struct em28xx *dev)
+{
+ struct usb_interface *intf;
+ struct usb_endpoint_descriptor *e, *ep = NULL;
+ struct usb_device *udev = interface_to_usbdev(dev->intf);
+ int i, ep_size, interval, num_urb, npackets;
+ int urb_size, bytes_per_transfer;
+ u8 alt;
+
+ if (dev->ifnum)
+ alt = 1;
+ else
+ alt = 7;
+
+ intf = usb_ifnum_to_if(udev, dev->ifnum);
+
+ if (intf->num_altsetting <= alt) {
+ dev_err(&dev->intf->dev, "alt %d doesn't exist on interface %d\n",
+ dev->ifnum, alt);
+ return -ENODEV;
+ }
+
+ for (i = 0; i < intf->altsetting[alt].desc.bNumEndpoints; i++) {
+ e = &intf->altsetting[alt].endpoint[i].desc;
+ if (!usb_endpoint_dir_in(e))
+ continue;
+ if (e->bEndpointAddress == EM28XX_EP_AUDIO) {
+ ep = e;
+ break;
+ }
+ }
+
+ if (!ep) {
+ dev_err(&dev->intf->dev, "Couldn't find an audio endpoint");
+ return -ENODEV;
+ }
+
+ ep_size = em28xx_audio_ep_packet_size(udev, ep);
+ interval = 1 << (ep->bInterval - 1);
+
+ dev_info(&dev->intf->dev,
+ "Endpoint 0x%02x %s on intf %d alt %d interval = %d, size %d\n",
+ EM28XX_EP_AUDIO, usb_speed_string(udev->speed),
+ dev->ifnum, alt, interval, ep_size);
+
+ /* Calculate the number and size of URBs to better fit the audio samples */
+
+ /*
+ * Estimate the number of bytes per DMA transfer.
+ *
+ * This is given by the bit rate (for now, only 48000 Hz) multiplied
+ * by 2 channels and 2 bytes/sample divided by the number of microframe
+ * intervals and by the microframe rate (125 us)
+ */
+ bytes_per_transfer = DIV_ROUND_UP(48000 * 2 * 2, 125 * interval);
+
+ /*
+ * Estimate the number of transfer URBs. Don't let it go past the
+ * maximum number of URBs that is known to be supported by the device.
+ */
+ num_urb = DIV_ROUND_UP(bytes_per_transfer, ep_size);
+ if (num_urb > EM28XX_MAX_AUDIO_BUFS)
+ num_urb = EM28XX_MAX_AUDIO_BUFS;
+
+ /*
+ * Now that we know the number of bytes per transfer and the number of
+ * URBs, estimate the typical size of an URB, in order to adjust the
+ * minimal number of packets.
+ */
+ urb_size = bytes_per_transfer / num_urb;
+
+ /*
+ * Now, calculate the amount of audio packets to be filled on each
+ * URB. In order to preserve the old behaviour, use a minimal
+ * threshold for this value.
+ */
+ npackets = EM28XX_MIN_AUDIO_PACKETS;
+ if (urb_size > ep_size * npackets)
+ npackets = DIV_ROUND_UP(urb_size, ep_size);
+
+ dev_info(&dev->intf->dev,
+ "Number of URBs: %d, with %d packets and %d size\n",
+ num_urb, npackets, urb_size);
+
+ /* Estimate the bytes per period */
+ dev->adev.period = urb_size * npackets;
+
+ /* Allocate space to store the number of URBs to be used */
+
+ dev->adev.transfer_buffer = kcalloc(num_urb,
+ sizeof(*dev->adev.transfer_buffer),
+ GFP_KERNEL);
+ if (!dev->adev.transfer_buffer)
+ return -ENOMEM;
+
+ dev->adev.urb = kcalloc(num_urb, sizeof(*dev->adev.urb), GFP_KERNEL);
+ if (!dev->adev.urb) {
+ kfree(dev->adev.transfer_buffer);
+ return -ENOMEM;
+ }
+
+ /* Alloc memory for each URB and for each transfer buffer */
+ dev->adev.num_urb = num_urb;
+ for (i = 0; i < num_urb; i++) {
+ struct urb *urb;
+ int j, k;
+ void *buf;
+
+ urb = usb_alloc_urb(npackets, GFP_KERNEL);
+ if (!urb) {
+ em28xx_audio_free_urb(dev);
+ return -ENOMEM;
+ }
+ dev->adev.urb[i] = urb;
+
+ buf = usb_alloc_coherent(udev, npackets * ep_size, GFP_KERNEL,
+ &urb->transfer_dma);
+ if (!buf) {
+ dev_err(&dev->intf->dev,
+ "usb_alloc_coherent failed!\n");
+ em28xx_audio_free_urb(dev);
+ return -ENOMEM;
+ }
+ dev->adev.transfer_buffer[i] = buf;
+
+ urb->dev = udev;
+ urb->context = dev;
+ urb->pipe = usb_rcvisocpipe(udev, EM28XX_EP_AUDIO);
+ urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
+ urb->transfer_buffer = buf;
+ urb->interval = interval;
+ urb->complete = em28xx_audio_isocirq;
+ urb->number_of_packets = npackets;
+ urb->transfer_buffer_length = ep_size * npackets;
+
+ for (j = k = 0; j < npackets; j++, k += ep_size) {
+ urb->iso_frame_desc[j].offset = k;
+ urb->iso_frame_desc[j].length = ep_size;
+ }
+ }
+
+ return 0;
+}
+
+static int em28xx_audio_init(struct em28xx *dev)
+{
+ struct em28xx_audio *adev = &dev->adev;
+ struct usb_device *udev = interface_to_usbdev(dev->intf);
+ struct snd_pcm *pcm;
+ struct snd_card *card;
+ static int devnr;
+ int err;
+
+ if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR) {
+ /*
+ * This device does not support the extension (in this case
+ * the device is expecting the snd-usb-audio module or
+ * doesn't have analog audio support at all)
+ */
+ return 0;
+ }
+
+ dev_info(&dev->intf->dev, "Binding audio extension\n");
+
+ kref_get(&dev->ref);
+
+ dev_info(&dev->intf->dev,
+ "em28xx-audio.c: Copyright (C) 2006 Markus Rechberger\n");
+ dev_info(&dev->intf->dev,
+ "em28xx-audio.c: Copyright (C) 2007-2016 Mauro Carvalho Chehab\n");
+
+ err = snd_card_new(&dev->intf->dev, index[devnr], "Em28xx Audio",
+ THIS_MODULE, 0, &card);
+ if (err < 0)
+ return err;
+
+ spin_lock_init(&adev->slock);
+ adev->sndcard = card;
+ adev->udev = udev;
+
+ err = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
+ if (err < 0)
+ goto card_free;
+
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
+ snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
+ pcm->info_flags = 0;
+ pcm->private_data = dev;
+ strscpy(pcm->name, "Empia 28xx Capture", sizeof(pcm->name));
+
+ strscpy(card->driver, "Em28xx-Audio", sizeof(card->driver));
+ strscpy(card->shortname, "Em28xx Audio", sizeof(card->shortname));
+ strscpy(card->longname, "Empia Em28xx Audio", sizeof(card->longname));
+
+ INIT_WORK(&adev->wq_trigger, audio_trigger);
+
+ if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
+ em28xx_cvol_new(card, dev, "Video", AC97_VIDEO);
+ em28xx_cvol_new(card, dev, "Line In", AC97_LINE);
+ em28xx_cvol_new(card, dev, "Phone", AC97_PHONE);
+ em28xx_cvol_new(card, dev, "Microphone", AC97_MIC);
+ em28xx_cvol_new(card, dev, "CD", AC97_CD);
+ em28xx_cvol_new(card, dev, "AUX", AC97_AUX);
+ em28xx_cvol_new(card, dev, "PCM", AC97_PCM);
+
+ em28xx_cvol_new(card, dev, "Master", AC97_MASTER);
+ em28xx_cvol_new(card, dev, "Line", AC97_HEADPHONE);
+ em28xx_cvol_new(card, dev, "Mono", AC97_MASTER_MONO);
+ em28xx_cvol_new(card, dev, "LFE", AC97_CENTER_LFE_MASTER);
+ em28xx_cvol_new(card, dev, "Surround", AC97_SURROUND_MASTER);
+ }
+
+ err = em28xx_audio_urb_init(dev);
+ if (err)
+ goto card_free;
+
+ err = snd_card_register(card);
+ if (err < 0)
+ goto urb_free;
+
+ dev_info(&dev->intf->dev, "Audio extension successfully initialized\n");
+ return 0;
+
+urb_free:
+ em28xx_audio_free_urb(dev);
+
+card_free:
+ snd_card_free(card);
+ adev->sndcard = NULL;
+
+ return err;
+}
+
+static int em28xx_audio_fini(struct em28xx *dev)
+{
+ if (!dev)
+ return 0;
+
+ if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR) {
+ /*
+ * This device does not support the extension (in this case
+ * the device is expecting the snd-usb-audio module or
+ * doesn't have analog audio support at all)
+ */
+ return 0;
+ }
+
+ dev_info(&dev->intf->dev, "Closing audio extension\n");
+
+ if (dev->adev.sndcard) {
+ snd_card_disconnect(dev->adev.sndcard);
+ flush_work(&dev->adev.wq_trigger);
+
+ em28xx_audio_free_urb(dev);
+
+ snd_card_free(dev->adev.sndcard);
+ dev->adev.sndcard = NULL;
+ }
+
+ kref_put(&dev->ref, em28xx_free_device);
+ return 0;
+}
+
+static int em28xx_audio_suspend(struct em28xx *dev)
+{
+ if (!dev)
+ return 0;
+
+ if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR)
+ return 0;
+
+ dev_info(&dev->intf->dev, "Suspending audio extension\n");
+ em28xx_deinit_isoc_audio(dev);
+ atomic_set(&dev->adev.stream_started, 0);
+ return 0;
+}
+
+static int em28xx_audio_resume(struct em28xx *dev)
+{
+ if (!dev)
+ return 0;
+
+ if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR)
+ return 0;
+
+ dev_info(&dev->intf->dev, "Resuming audio extension\n");
+ /* Nothing to do other than schedule_work() ?? */
+ schedule_work(&dev->adev.wq_trigger);
+ return 0;
+}
+
+static struct em28xx_ops audio_ops = {
+ .id = EM28XX_AUDIO,
+ .name = "Em28xx Audio Extension",
+ .init = em28xx_audio_init,
+ .fini = em28xx_audio_fini,
+ .suspend = em28xx_audio_suspend,
+ .resume = em28xx_audio_resume,
+};
+
+static int __init em28xx_alsa_register(void)
+{
+ return em28xx_register_extension(&audio_ops);
+}
+
+static void __exit em28xx_alsa_unregister(void)
+{
+ em28xx_unregister_extension(&audio_ops);
+}
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
+MODULE_AUTHOR("Mauro Carvalho Chehab");
+MODULE_DESCRIPTION(DRIVER_DESC " - audio interface");
+MODULE_VERSION(EM28XX_VERSION);
+
+module_init(em28xx_alsa_register);
+module_exit(em28xx_alsa_unregister);