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 e486f48660f..312f90d7ec6 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 e5b1634d9ad..d71ed8935f7 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 00000000000..a6f19f57a1c
--- /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 775dbd5f344..9d4a6714f9e 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 1e20e60ba6a..3c61ca2e615 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);