ALSA: add Apple iSight microphone driver

This adds an experimental driver for the front and rear microphones of
the Apple iSight web camera.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

5 files changed, 765 insertions, 0 deletions

diff --git a/sound/firewire/Kconfig b/sound/firewire/Kconfig
index e486f48..312f90d 100644
--- a/sound/firewire/Kconfig
+++ b/sound/firewire/Kconfig
@@ -22,4 +22,16 @@ config SND_FIREWIRE_SPEAKERS
 	  To compile this driver as a module, choose M here: the module
 	  will be called snd-firewire-speakers.
 
+config SND_ISIGHT
+	tristate "Apple iSight microphone (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	select SND_PCM
+	select SND_FIREWIRE_LIB
+	help
+	  Say Y here to include support for the front and rear microphones
+	  of the Apple iSight web camera.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-isight.
+
 endif # SND_FIREWIRE
diff --git a/sound/firewire/Makefile b/sound/firewire/Makefile
index e5b1634..d71ed89 100644
--- a/sound/firewire/Makefile
+++ b/sound/firewire/Makefile
@@ -1,6 +1,8 @@
 snd-firewire-lib-objs := lib.o iso-resources.o packets-buffer.o \
 			 fcp.o cmp.o amdtp.o
 snd-firewire-speakers-objs := speakers.o
+snd-isight-objs := isight.o
 
 obj-$(CONFIG_SND_FIREWIRE_LIB) += snd-firewire-lib.o
 obj-$(CONFIG_SND_FIREWIRE_SPEAKERS) += snd-firewire-speakers.o
+obj-$(CONFIG_SND_ISIGHT) += snd-isight.o
diff --git a/sound/firewire/isight.c b/sound/firewire/isight.c
new file mode 100644
index 0000000..a6f19f5
--- /dev/null
+++ b/sound/firewire/isight.c
@@ -0,0 +1,744 @@
+/*
+ * Apple iSight audio driver
+ *
+ * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <sound/control.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/tlv.h>
+#include "lib.h"
+#include "iso-resources.h"
+#include "packets-buffer.h"
+
+#define OUI_APPLE		0x000a27
+#define MODEL_APPLE_ISIGHT	0x000008
+#define SW_ISIGHT_AUDIO		0x000010
+
+#define REG_AUDIO_ENABLE	0x000
+#define  AUDIO_ENABLE		0x80000000
+#define REG_DEF_AUDIO_GAIN	0x204
+#define REG_GAIN_RAW_START	0x210
+#define REG_GAIN_RAW_END	0x214
+#define REG_GAIN_DB_START	0x218
+#define REG_GAIN_DB_END		0x21c
+#define REG_SAMPLE_RATE_INQUIRY	0x280
+#define REG_ISO_TX_CONFIG	0x300
+#define  SPEED_SHIFT		16
+#define REG_SAMPLE_RATE		0x400
+#define  RATE_48000		0x80000000
+#define REG_GAIN		0x500
+#define REG_MUTE		0x504
+
+#define MAX_FRAMES_PER_PACKET	475
+
+#define QUEUE_LENGTH		20
+
+struct isight {
+	struct snd_card *card;
+	struct fw_unit *unit;
+	struct fw_device *device;
+	u64 audio_base;
+	struct fw_address_handler iris_handler;
+	struct snd_pcm_substream *pcm;
+	struct mutex mutex;
+	struct iso_packets_buffer buffer;
+	struct fw_iso_resources resources;
+	struct fw_iso_context *context;
+	bool pcm_running;
+	bool first_packet;
+	int packet_index;
+	u32 total_samples;
+	unsigned int buffer_pointer;
+	unsigned int period_counter;
+	s32 gain_min, gain_max;
+	unsigned int gain_tlv[4];
+};
+
+struct audio_payload {
+	__be32 sample_count;
+	__be32 signature;
+	__be32 sample_total;
+	__be32 reserved;
+	__be16 samples[2 * MAX_FRAMES_PER_PACKET];
+};
+
+MODULE_DESCRIPTION("iSight audio driver");
+MODULE_AUTHOR("Clemens Ladisch <clemens@ladisch.de>");
+MODULE_LICENSE("GPL v2");
+
+static struct fw_iso_packet audio_packet = {
+	.payload_length = sizeof(struct audio_payload),
+	.interrupt = 1,
+};
+
+static void isight_update_pointers(struct isight *isight, unsigned int count)
+{
+	struct snd_pcm_runtime *runtime = isight->pcm->runtime;
+	unsigned int ptr;
+
+	smp_wmb(); /* update buffer data before buffer pointer */
+
+	ptr = isight->buffer_pointer;
+	ptr += count;
+	if (ptr >= runtime->buffer_size)
+		ptr -= runtime->buffer_size;
+	ACCESS_ONCE(isight->buffer_pointer) = ptr;
+
+	isight->period_counter += count;
+	if (isight->period_counter >= runtime->period_size) {
+		isight->period_counter -= runtime->period_size;
+		snd_pcm_period_elapsed(isight->pcm);
+	}
+}
+
+static void isight_samples(struct isight *isight,
+			   const __be16 *samples, unsigned int count)
+{
+	struct snd_pcm_runtime *runtime;
+	unsigned int count1;
+
+	if (!ACCESS_ONCE(isight->pcm_running))
+		return;
+
+	runtime = isight->pcm->runtime;
+	if (isight->buffer_pointer + count <= runtime->buffer_size) {
+		memcpy(runtime->dma_area + isight->buffer_pointer * 4,
+		       samples, count * 4);
+	} else {
+		count1 = runtime->buffer_size - isight->buffer_pointer;
+		memcpy(runtime->dma_area + isight->buffer_pointer * 4,
+		       samples, count1 * 4);
+		samples += count1 * 2;
+		memcpy(runtime->dma_area, samples, (count - count1) * 4);
+	}
+
+	isight_update_pointers(isight, count);
+}
+
+static void isight_pcm_abort(struct isight *isight)
+{
+	unsigned long flags;
+
+	snd_pcm_stream_lock_irqsave(isight->pcm, flags);
+	if (snd_pcm_running(isight->pcm))
+		snd_pcm_stop(isight->pcm, SNDRV_PCM_STATE_XRUN);
+	snd_pcm_stream_unlock_irqrestore(isight->pcm, flags);
+}
+
+static void isight_dropped_samples(struct isight *isight, unsigned int total)
+{
+	struct snd_pcm_runtime *runtime;
+	u32 dropped;
+	unsigned int count1;
+
+	if (!ACCESS_ONCE(isight->pcm_running))
+		return;
+
+	runtime = isight->pcm->runtime;
+	dropped = total - isight->total_samples;
+	if (dropped < runtime->buffer_size) {
+		if (isight->buffer_pointer + dropped <= runtime->buffer_size) {
+			memset(runtime->dma_area + isight->buffer_pointer * 4,
+			       0, dropped * 4);
+		} else {
+			count1 = runtime->buffer_size - isight->buffer_pointer;
+			memset(runtime->dma_area + isight->buffer_pointer * 4,
+			       0, count1 * 4);
+			memset(runtime->dma_area, 0, (dropped - count1) * 4);
+		}
+		isight_update_pointers(isight, dropped);
+	} else {
+		isight_pcm_abort(isight);
+	}
+}
+
+static void isight_packet(struct fw_iso_context *context, u32 cycle,
+			  size_t header_length, void *header, void *data)
+{
+	struct isight *isight = data;
+	const struct audio_payload *payload;
+	unsigned int index, length, count, total;
+	int err;
+
+	if (isight->packet_index < 0)
+		return;
+	index = isight->packet_index;
+	payload = isight->buffer.packets[index].buffer;
+	length = be32_to_cpup(header) >> 16;
+
+	if (likely(length >= 16 &&
+		   payload->signature == cpu_to_be32(0x73676874/*"sght"*/))) {
+		count = be32_to_cpu(payload->sample_count);
+		if (likely(count <= (length - 16) / 4)) {
+			total = be32_to_cpu(payload->sample_total);
+			if (unlikely(total != isight->total_samples)) {
+				if (!isight->first_packet)
+					isight_dropped_samples(isight, total);
+				isight->first_packet = false;
+				isight->total_samples = total;
+			}
+
+			isight_samples(isight, payload->samples, count);
+			isight->total_samples += count;
+		}
+	}
+
+	if (++index >= QUEUE_LENGTH)
+		index = 0;
+
+	err = fw_iso_context_queue(isight->context, &audio_packet,
+				   &isight->buffer.iso_buffer,
+				   isight->buffer.packets[index].offset);
+	if (err < 0) {
+		dev_err(&isight->unit->device, "queueing error: %d\n", err);
+		isight_pcm_abort(isight);
+		isight->packet_index = -1;
+		return;
+	}
+
+	isight->packet_index = index;
+}
+
+static int isight_connect(struct isight *isight)
+{
+	int ch, err, rcode, errors = 0;
+	__be32 value;
+
+retry_after_bus_reset:
+	ch = fw_iso_resources_allocate(&isight->resources,
+				       sizeof(struct audio_payload),
+				       isight->device->max_speed);
+	if (ch < 0) {
+		err = ch;
+		goto error;
+	}
+
+	value = cpu_to_be32(ch | (isight->device->max_speed << SPEED_SHIFT));
+	for (;;) {
+		rcode = fw_run_transaction(
+				isight->device->card,
+				TCODE_WRITE_QUADLET_REQUEST,
+				isight->device->node_id,
+				isight->resources.generation,
+				isight->device->max_speed,
+				isight->audio_base + REG_ISO_TX_CONFIG,
+				&value, 4);
+		if (rcode == RCODE_COMPLETE) {
+			return 0;
+		} else if (rcode == RCODE_GENERATION) {
+			fw_iso_resources_free(&isight->resources);
+			goto retry_after_bus_reset;
+		} else if (rcode_is_permanent_error(rcode) || ++errors >= 3) {
+			err = -EIO;
+			goto err_resources;
+		}
+		msleep(5);
+	}
+
+err_resources:
+	fw_iso_resources_free(&isight->resources);
+error:
+	return err;
+}
+
+static int isight_open(struct snd_pcm_substream *substream)
+{
+	static const struct snd_pcm_hardware hardware = {
+		.info = SNDRV_PCM_INFO_MMAP |
+			SNDRV_PCM_INFO_MMAP_VALID |
+			SNDRV_PCM_INFO_BATCH |
+			SNDRV_PCM_INFO_INTERLEAVED |
+			SNDRV_PCM_INFO_BLOCK_TRANSFER,
+		.formats = SNDRV_PCM_FMTBIT_S16_BE,
+		.rates = SNDRV_PCM_RATE_48000,
+		.rate_min = 48000,
+		.rate_max = 48000,
+		.channels_min = 2,
+		.channels_max = 2,
+		.buffer_bytes_max = 4 * 1024 * 1024,
+		.period_bytes_min = MAX_FRAMES_PER_PACKET * 4,
+		.period_bytes_max = 1024 * 1024,
+		.periods_min = 2,
+		.periods_max = UINT_MAX,
+	};
+	struct isight *isight = substream->private_data;
+
+	substream->runtime->hw = hardware;
+
+	return iso_packets_buffer_init(&isight->buffer, isight->unit,
+				       QUEUE_LENGTH,
+				       sizeof(struct audio_payload),
+				       DMA_FROM_DEVICE);
+}
+
+static int isight_close(struct snd_pcm_substream *substream)
+{
+	struct isight *isight = substream->private_data;
+
+	iso_packets_buffer_destroy(&isight->buffer, isight->unit);
+
+	return 0;
+}
+
+static int isight_hw_params(struct snd_pcm_substream *substream,
+			    struct snd_pcm_hw_params *hw_params)
+{
+	return snd_pcm_lib_alloc_vmalloc_buffer(substream,
+						params_buffer_bytes(hw_params));
+}
+
+static void isight_stop_streaming(struct isight *isight)
+{
+	__be32 value;
+
+	if (!isight->context)
+		return;
+
+	fw_iso_context_stop(isight->context);
+	fw_iso_context_destroy(isight->context);
+	isight->context = NULL;
+
+	value = 0;
+	snd_fw_transaction(isight->unit, TCODE_WRITE_QUADLET_REQUEST,
+			   isight->audio_base + REG_AUDIO_ENABLE,
+			   &value, 4);
+
+	fw_iso_resources_free(&isight->resources);
+}
+
+static int isight_hw_free(struct snd_pcm_substream *substream)
+{
+	struct isight *isight = substream->private_data;
+
+	mutex_lock(&isight->mutex);
+	isight_stop_streaming(isight);
+	mutex_unlock(&isight->mutex);
+
+	return snd_pcm_lib_free_vmalloc_buffer(substream);
+}
+
+static int isight_start_streaming(struct isight *isight)
+{
+	__be32 sample_rate;
+	unsigned int i;
+	int err;
+
+	if (isight->context) {
+		if (isight->packet_index < 0)
+			isight_stop_streaming(isight);
+		else
+			return 0;
+	}
+
+	sample_rate = cpu_to_be32(RATE_48000);
+	err = snd_fw_transaction(isight->unit, TCODE_WRITE_QUADLET_REQUEST,
+				 isight->audio_base + REG_SAMPLE_RATE,
+				 &sample_rate, 4);
+	if (err < 0)
+		return err;
+
+	err = isight_connect(isight);
+	if (err < 0)
+		goto error;
+
+	isight->context = fw_iso_context_create(isight->device->card,
+						FW_ISO_CONTEXT_RECEIVE,
+						isight->resources.channel,
+						isight->device->max_speed,
+						4, isight_packet, isight);
+	if (IS_ERR(isight->context)) {
+		err = PTR_ERR(isight->context);
+		isight->context = NULL;
+		goto err_resources;
+	}
+
+	for (i = 0; i < QUEUE_LENGTH; ++i) {
+		err = fw_iso_context_queue(isight->context, &audio_packet,
+					   &isight->buffer.iso_buffer,
+					   isight->buffer.packets[i].offset);
+		if (err < 0)
+			goto err_context;
+	}
+
+	isight->first_packet = true;
+	isight->packet_index = 0;
+
+	err = fw_iso_context_start(isight->context, -1, 0,
+				   FW_ISO_CONTEXT_MATCH_ALL_TAGS/*?*/);
+	if (err < 0)
+		goto err_context;
+
+	return 0;
+
+err_context:
+	fw_iso_context_destroy(isight->context);
+	isight->context = NULL;
+err_resources:
+	fw_iso_resources_free(&isight->resources);
+error:
+	return err;
+}
+
+static int isight_prepare(struct snd_pcm_substream *substream)
+{
+	struct isight *isight = substream->private_data;
+	int err;
+
+	isight->buffer_pointer = 0;
+	isight->period_counter = 0;
+
+	mutex_lock(&isight->mutex);
+	err = isight_start_streaming(isight);
+	mutex_unlock(&isight->mutex);
+
+	return err;
+}
+
+static int isight_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct isight *isight = substream->private_data;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		ACCESS_ONCE(isight->pcm_running) = true;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		ACCESS_ONCE(isight->pcm_running) = false;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static snd_pcm_uframes_t isight_pointer(struct snd_pcm_substream *substream)
+{
+	struct isight *isight = substream->private_data;
+
+	return ACCESS_ONCE(isight->buffer_pointer);
+}
+
+static int isight_create_pcm(struct isight *isight)
+{
+	static struct snd_pcm_ops ops = {
+		.open      = isight_open,
+		.close     = isight_close,
+		.ioctl     = snd_pcm_lib_ioctl,
+		.hw_params = isight_hw_params,
+		.hw_free   = isight_hw_free,
+		.prepare   = isight_prepare,
+		.trigger   = isight_trigger,
+		.pointer   = isight_pointer,
+		.page      = snd_pcm_lib_get_vmalloc_page,
+		.mmap      = snd_pcm_lib_mmap_vmalloc,
+	};
+	struct snd_pcm *pcm;
+	int err;
+
+	err = snd_pcm_new(isight->card, "iSight", 0, 0, 1, &pcm);
+	if (err < 0)
+		return err;
+	pcm->private_data = isight;
+	strcpy(pcm->name, "iSight");
+	isight->pcm = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
+	isight->pcm->ops = &ops;
+
+	return 0;
+}
+
+static int isight_gain_info(struct snd_kcontrol *ctl,
+			    struct snd_ctl_elem_info *info)
+{
+	struct isight *isight = ctl->private_data;
+
+	info->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	info->count = 1;
+	info->value.integer.min = isight->gain_min;
+	info->value.integer.max = isight->gain_max;
+
+	return 0;
+}
+
+static int isight_gain_get(struct snd_kcontrol *ctl,
+			   struct snd_ctl_elem_value *value)
+{
+	struct isight *isight = ctl->private_data;
+	__be32 gain;
+	int err;
+
+	err = snd_fw_transaction(isight->unit, TCODE_READ_QUADLET_REQUEST,
+				 isight->audio_base + REG_GAIN, &gain, 4);
+	if (err < 0)
+		return err;
+
+	value->value.integer.value[0] = (s32)be32_to_cpu(gain);
+
+	return 0;
+}
+
+static int isight_gain_put(struct snd_kcontrol *ctl,
+			   struct snd_ctl_elem_value *value)
+{
+	struct isight *isight = ctl->private_data;
+	__be32 gain;
+
+	if (value->value.integer.value[0] < isight->gain_min ||
+	    value->value.integer.value[0] > isight->gain_max)
+		return -EINVAL;
+
+	gain = cpu_to_be32(value->value.integer.value[0]);
+	return snd_fw_transaction(isight->unit, TCODE_WRITE_QUADLET_REQUEST,
+				  isight->audio_base + REG_GAIN, &gain, 4);
+}
+
+static int isight_mute_get(struct snd_kcontrol *ctl,
+			   struct snd_ctl_elem_value *value)
+{
+	struct isight *isight = ctl->private_data;
+	__be32 mute;
+	int err;
+
+	err = snd_fw_transaction(isight->unit, TCODE_READ_QUADLET_REQUEST,
+				 isight->audio_base + REG_MUTE, &mute, 4);
+	if (err < 0)
+		return err;
+
+	value->value.integer.value[0] = !mute;
+
+	return 0;
+}
+
+static int isight_mute_put(struct snd_kcontrol *ctl,
+			   struct snd_ctl_elem_value *value)
+{
+	struct isight *isight = ctl->private_data;
+	__be32 mute;
+
+	mute = (__force __be32)!value->value.integer.value[0];
+	return snd_fw_transaction(isight->unit, TCODE_WRITE_QUADLET_REQUEST,
+				  isight->audio_base + REG_MUTE, &mute, 4);
+}
+
+static int isight_create_mixer(struct isight *isight)
+{
+	static const struct snd_kcontrol_new gain_control = {
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Mic Capture Volume",
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+			  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+		.info = isight_gain_info,
+		.get = isight_gain_get,
+		.put = isight_gain_put,
+	};
+	static const struct snd_kcontrol_new mute_control = {
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Mic Capture Switch",
+		.info = snd_ctl_boolean_mono_info,
+		.get = isight_mute_get,
+		.put = isight_mute_put,
+	};
+	__be32 value;
+	struct snd_kcontrol *ctl;
+	int err;
+
+	err = snd_fw_transaction(isight->unit, TCODE_READ_QUADLET_REQUEST,
+				 isight->audio_base + REG_GAIN_RAW_START,
+				 &value, 4);
+	if (err < 0)
+		return err;
+	isight->gain_min = be32_to_cpu(value);
+
+	err = snd_fw_transaction(isight->unit, TCODE_READ_QUADLET_REQUEST,
+				 isight->audio_base + REG_GAIN_RAW_END,
+				 &value, 4);
+	if (err < 0)
+		return err;
+	isight->gain_max = be32_to_cpu(value);
+
+	isight->gain_tlv[0] = SNDRV_CTL_TLVT_DB_MINMAX;
+	isight->gain_tlv[1] = 2 * sizeof(unsigned int);
+	err = snd_fw_transaction(isight->unit, TCODE_READ_QUADLET_REQUEST,
+				 isight->audio_base + REG_GAIN_DB_START,
+				 &value, 4);
+	if (err < 0)
+		return err;
+	isight->gain_tlv[2] = (s32)be32_to_cpu(value) * 100;
+	err = snd_fw_transaction(isight->unit, TCODE_READ_QUADLET_REQUEST,
+				 isight->audio_base + REG_GAIN_DB_END,
+				 &value, 4);
+	if (err < 0)
+		return err;
+	isight->gain_tlv[3] = (s32)be32_to_cpu(value) * 100;
+
+	ctl = snd_ctl_new1(&gain_control, isight);
+	if (ctl)
+		ctl->tlv.p = isight->gain_tlv;
+	err = snd_ctl_add(isight->card, ctl);
+	if (err < 0)
+		return err;
+
+	err = snd_ctl_add(isight->card, snd_ctl_new1(&mute_control, isight));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static void isight_card_free(struct snd_card *card)
+{
+	struct isight *isight = card->private_data;
+
+	fw_iso_resources_destroy(&isight->resources);
+	fw_unit_put(isight->unit);
+	fw_device_put(isight->device);
+	mutex_destroy(&isight->mutex);
+}
+
+static u64 get_unit_base(struct fw_unit *unit)
+{
+	struct fw_csr_iterator i;
+	int key, value;
+
+	fw_csr_iterator_init(&i, unit->directory);
+	while (fw_csr_iterator_next(&i, &key, &value))
+		if (key == CSR_OFFSET)
+			return CSR_REGISTER_BASE + value * 4;
+	return 0;
+}
+
+static int isight_probe(struct device *unit_dev)
+{
+	struct fw_unit *unit = fw_unit(unit_dev);
+	struct fw_device *fw_dev = fw_parent_device(unit);
+	struct snd_card *card;
+	struct isight *isight;
+	int err;
+
+	err = snd_card_create(-1, NULL, THIS_MODULE, sizeof(*isight), &card);
+	if (err < 0)
+		return err;
+	snd_card_set_dev(card, unit_dev);
+
+	isight = card->private_data;
+	isight->card = card;
+	mutex_init(&isight->mutex);
+	isight->unit = fw_unit_get(unit);
+	isight->device = fw_device_get(fw_dev);
+	isight->audio_base = get_unit_base(unit);
+	if (!isight->audio_base) {
+		dev_err(&unit->device, "audio unit base not found\n");
+		err = -ENXIO;
+		goto err_unit;
+	}
+	fw_iso_resources_init(&isight->resources, unit);
+
+	card->private_free = isight_card_free;
+
+	strcpy(card->driver, "iSight");
+	strcpy(card->shortname, "Apple iSight");
+	snprintf(card->longname, sizeof(card->longname),
+		 "Apple iSight (GUID %08x%08x) at %s, S%d",
+		 fw_dev->config_rom[3], fw_dev->config_rom[4],
+		 dev_name(&unit->device), 100 << fw_dev->max_speed);
+	strcpy(card->mixername, "iSight");
+
+	err = isight_create_pcm(isight);
+	if (err < 0)
+		goto error;
+
+	err = isight_create_mixer(isight);
+	if (err < 0)
+		goto error;
+
+	err = snd_card_register(card);
+	if (err < 0)
+		goto error;
+
+	dev_set_drvdata(unit_dev, isight);
+
+	return 0;
+
+err_unit:
+	fw_unit_put(isight->unit);
+	fw_device_put(isight->device);
+	mutex_destroy(&isight->mutex);
+error:
+	snd_card_free(card);
+	return err;
+}
+
+static int isight_remove(struct device *dev)
+{
+	struct isight *isight = dev_get_drvdata(dev);
+
+	snd_card_disconnect(isight->card);
+
+	mutex_lock(&isight->mutex);
+	isight_pcm_abort(isight);
+	isight_stop_streaming(isight);
+	mutex_unlock(&isight->mutex);
+
+	snd_card_free_when_closed(isight->card);
+
+	return 0;
+}
+
+static void isight_bus_reset(struct fw_unit *unit)
+{
+	struct isight *isight = dev_get_drvdata(&unit->device);
+
+	mutex_lock(&isight->mutex);
+	if (fw_iso_resources_update(&isight->resources) < 0) {
+		isight_pcm_abort(isight);
+		isight_stop_streaming(isight);
+	}
+	mutex_unlock(&isight->mutex);
+}
+
+static const struct ieee1394_device_id isight_id_table[] = {
+	{
+		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
+				IEEE1394_MATCH_VERSION,
+		.specifier_id = OUI_APPLE,
+		.version      = SW_ISIGHT_AUDIO,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(ieee1394, isight_id_table);
+
+static struct fw_driver isight_driver = {
+	.driver   = {
+		.owner	= THIS_MODULE,
+		.name	= KBUILD_MODNAME,
+		.bus	= &fw_bus_type,
+		.probe	= isight_probe,
+		.remove	= isight_remove,
+	},
+	.update   = isight_bus_reset,
+	.id_table = isight_id_table,
+};
+
+static int __init alsa_isight_init(void)
+{
+	return driver_register(&isight_driver.driver);
+}
+
+static void __exit alsa_isight_exit(void)
+{
+	driver_unregister(&isight_driver.driver);
+}
+
+module_init(alsa_isight_init);
+module_exit(alsa_isight_exit);
diff --git a/sound/firewire/iso-resources.c b/sound/firewire/iso-resources.c
index 775dbd5..9d4a671 100644
--- a/sound/firewire/iso-resources.c
+++ b/sound/firewire/iso-resources.c
@@ -36,6 +36,7 @@ int fw_iso_resources_init(struct fw_iso_resources *r, struct fw_unit *unit)
 
 	return 0;
 }
+EXPORT_SYMBOL(fw_iso_resources_init);
 
 /**
  * fw_iso_resources_destroy - destroy a resource manager
@@ -48,6 +49,7 @@ void fw_iso_resources_destroy(struct fw_iso_resources *r)
 	mutex_destroy(&r->mutex);
 	fw_unit_put(r->unit);
 }
+EXPORT_SYMBOL(fw_iso_resources_destroy);
 
 static unsigned int packet_bandwidth(unsigned int max_payload_bytes, int speed)
 {
@@ -152,6 +154,7 @@ retry_after_bus_reset:
 
 	return channel;
 }
+EXPORT_SYMBOL(fw_iso_resources_allocate);
 
 /**
  * fw_iso_resources_update - update resource allocations after a bus reset
@@ -203,6 +206,7 @@ int fw_iso_resources_update(struct fw_iso_resources *r)
 
 	return channel;
 }
+EXPORT_SYMBOL(fw_iso_resources_update);
 
 /**
  * fw_iso_resources_free - frees allocated resources
@@ -230,3 +234,4 @@ void fw_iso_resources_free(struct fw_iso_resources *r)
 
 	mutex_unlock(&r->mutex);
 }
+EXPORT_SYMBOL(fw_iso_resources_free);
diff --git a/sound/firewire/packets-buffer.c b/sound/firewire/packets-buffer.c
index 1e20e60..3c61ca2 100644
--- a/sound/firewire/packets-buffer.c
+++ b/sound/firewire/packets-buffer.c
@@ -60,6 +60,7 @@ err_packets:
 error:
 	return err;
 }
+EXPORT_SYMBOL(iso_packets_buffer_init);
 
 /**
  * iso_packets_buffer_destroy - frees packet buffer resources
@@ -72,3 +73,4 @@ void iso_packets_buffer_destroy(struct iso_packets_buffer *b,
 	fw_iso_buffer_destroy(&b->iso_buffer, fw_parent_device(unit)->card);
 	kfree(b->packets);
 }
+EXPORT_SYMBOL(iso_packets_buffer_destroy);