ALSA: oxfw: Add hwdep interface

This interface is designed for mixer/control application. By using this
interface, an application can get information about firewire node, can
lock/unlock kernel streaming and can get notification at starting/stopping
kernel streaming.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

8 files changed, 276 insertions, 2 deletions

diff --git a/sound/firewire/Kconfig b/sound/firewire/Kconfig
index 6364e5b90a00..ecec547782b2 100644
--- a/sound/firewire/Kconfig
+++ b/sound/firewire/Kconfig
@@ -26,6 +26,7 @@ config SND_DICE
 config SND_OXFW
         tristate "Oxford Semiconductor FW970/971 chipset support"
         select SND_FIREWIRE_LIB
+        select SND_HWDEP
         help
           Say Y here to include support for FireWire devices based on
           Oxford Semiconductor FW970/971 chipset.
diff --git a/sound/firewire/oxfw/Makefile b/sound/firewire/oxfw/Makefile
index 3904a302d48e..a926850864f6 100644
--- a/sound/firewire/oxfw/Makefile
+++ b/sound/firewire/oxfw/Makefile
@@ -1,3 +1,3 @@
 snd-oxfw-objs := oxfw-command.o oxfw-stream.o oxfw-control.o oxfw-pcm.o \
-                 oxfw-proc.o oxfw-midi.o oxfw.o
+                 oxfw-proc.o oxfw-midi.o oxfw-hwdep.o oxfw.o
 obj-m += snd-oxfw.o
diff --git a/sound/firewire/oxfw/oxfw-hwdep.c b/sound/firewire/oxfw/oxfw-hwdep.c
new file mode 100644
index 000000000000..ff2687ad0460
--- /dev/null
+++ b/sound/firewire/oxfw/oxfw-hwdep.c
@@ -0,0 +1,190 @@
+/*
+ * oxfw_hwdep.c - a part of driver for OXFW970/971 based devices
+ *
+ * Copyright (c) 2014 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+/*
+ * This codes give three functionality.
+ *
+ * 1.get firewire node information
+ * 2.get notification about starting/stopping stream
+ * 3.lock/unlock stream
+ */
+
+#include "oxfw.h"
+
+static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
+                       loff_t *offset)
+{
+        struct snd_oxfw *oxfw = hwdep->private_data;
+        DEFINE_WAIT(wait);
+        union snd_firewire_event event;
+
+        spin_lock_irq(&oxfw->lock);
+
+        while (!oxfw->dev_lock_changed) {
+                prepare_to_wait(&oxfw->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
+                spin_unlock_irq(&oxfw->lock);
+                schedule();
+                finish_wait(&oxfw->hwdep_wait, &wait);
+                if (signal_pending(current))
+                        return -ERESTARTSYS;
+                spin_lock_irq(&oxfw->lock);
+        }
+
+        memset(&event, 0, sizeof(event));
+        if (oxfw->dev_lock_changed) {
+                event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
+                event.lock_status.status = (oxfw->dev_lock_count > 0);
+                oxfw->dev_lock_changed = false;
+
+                count = min_t(long, count, sizeof(event.lock_status));
+        }
+
+        spin_unlock_irq(&oxfw->lock);
+
+        if (copy_to_user(buf, &event, count))
+                return -EFAULT;
+
+        return count;
+}
+
+static unsigned int hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
+                               poll_table *wait)
+{
+        struct snd_oxfw *oxfw = hwdep->private_data;
+        unsigned int events;
+
+        poll_wait(file, &oxfw->hwdep_wait, wait);
+
+        spin_lock_irq(&oxfw->lock);
+        if (oxfw->dev_lock_changed)
+                events = POLLIN | POLLRDNORM;
+        else
+                events = 0;
+        spin_unlock_irq(&oxfw->lock);
+
+        return events;
+}
+
+static int hwdep_get_info(struct snd_oxfw *oxfw, void __user *arg)
+{
+        struct fw_device *dev = fw_parent_device(oxfw->unit);
+        struct snd_firewire_get_info info;
+
+        memset(&info, 0, sizeof(info));
+        info.type = SNDRV_FIREWIRE_TYPE_OXFW;
+        info.card = dev->card->index;
+        *(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
+        *(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
+        strlcpy(info.device_name, dev_name(&dev->device),
+                sizeof(info.device_name));
+
+        if (copy_to_user(arg, &info, sizeof(info)))
+                return -EFAULT;
+
+        return 0;
+}
+
+static int hwdep_lock(struct snd_oxfw *oxfw)
+{
+        int err;
+
+        spin_lock_irq(&oxfw->lock);
+
+        if (oxfw->dev_lock_count == 0) {
+                oxfw->dev_lock_count = -1;
+                err = 0;
+        } else {
+                err = -EBUSY;
+        }
+
+        spin_unlock_irq(&oxfw->lock);
+
+        return err;
+}
+
+static int hwdep_unlock(struct snd_oxfw *oxfw)
+{
+        int err;
+
+        spin_lock_irq(&oxfw->lock);
+
+        if (oxfw->dev_lock_count == -1) {
+                oxfw->dev_lock_count = 0;
+                err = 0;
+        } else {
+                err = -EBADFD;
+        }
+
+        spin_unlock_irq(&oxfw->lock);
+
+        return err;
+}
+
+static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
+{
+        struct snd_oxfw *oxfw = hwdep->private_data;
+
+        spin_lock_irq(&oxfw->lock);
+        if (oxfw->dev_lock_count == -1)
+                oxfw->dev_lock_count = 0;
+        spin_unlock_irq(&oxfw->lock);
+
+        return 0;
+}
+
+static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
+                       unsigned int cmd, unsigned long arg)
+{
+        struct snd_oxfw *oxfw = hwdep->private_data;
+
+        switch (cmd) {
+        case SNDRV_FIREWIRE_IOCTL_GET_INFO:
+                return hwdep_get_info(oxfw, (void __user *)arg);
+        case SNDRV_FIREWIRE_IOCTL_LOCK:
+                return hwdep_lock(oxfw);
+        case SNDRV_FIREWIRE_IOCTL_UNLOCK:
+                return hwdep_unlock(oxfw);
+        default:
+                return -ENOIOCTLCMD;
+        }
+}
+
+#ifdef CONFIG_COMPAT
+static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
+                              unsigned int cmd, unsigned long arg)
+{
+        return hwdep_ioctl(hwdep, file, cmd,
+                           (unsigned long)compat_ptr(arg));
+}
+#else
+#define hwdep_compat_ioctl NULL
+#endif
+
+int snd_oxfw_create_hwdep(struct snd_oxfw *oxfw)
+{
+        static const struct snd_hwdep_ops hwdep_ops = {
+                .read           = hwdep_read,
+                .release        = hwdep_release,
+                .poll           = hwdep_poll,
+                .ioctl          = hwdep_ioctl,
+                .ioctl_compat   = hwdep_compat_ioctl,
+        };
+        struct snd_hwdep *hwdep;
+        int err;
+
+        err = snd_hwdep_new(oxfw->card, oxfw->card->driver, 0, &hwdep);
+        if (err < 0)
+                goto end;
+        strcpy(hwdep->name, oxfw->card->driver);
+        hwdep->iface = SNDRV_HWDEP_IFACE_FW_OXFW;
+        hwdep->ops = hwdep_ops;
+        hwdep->private_data = oxfw;
+        hwdep->exclusive = true;
+end:
+        return err;
+}
diff --git a/sound/firewire/oxfw/oxfw-midi.c b/sound/firewire/oxfw/oxfw-midi.c
index 334b11d1a422..540a30338516 100644
--- a/sound/firewire/oxfw/oxfw-midi.c
+++ b/sound/firewire/oxfw/oxfw-midi.c
@@ -13,6 +13,10 @@ static int midi_capture_open(struct snd_rawmidi_substream *substream)
         struct snd_oxfw *oxfw = substream->rmidi->private_data;
         int err;
 
+        err = snd_oxfw_stream_lock_try(oxfw);
+        if (err < 0)
+                return err;
+
         mutex_lock(&oxfw->mutex);
 
         oxfw->capture_substreams++;
@@ -20,6 +24,9 @@ static int midi_capture_open(struct snd_rawmidi_substream *substream)
 
         mutex_unlock(&oxfw->mutex);
 
+        if (err < 0)
+                snd_oxfw_stream_lock_release(oxfw);
+
         return err;
 }
 
@@ -28,6 +35,10 @@ static int midi_playback_open(struct snd_rawmidi_substream *substream)
         struct snd_oxfw *oxfw = substream->rmidi->private_data;
         int err;
 
+        err = snd_oxfw_stream_lock_try(oxfw);
+        if (err < 0)
+                return err;
+
         mutex_lock(&oxfw->mutex);
 
         oxfw->playback_substreams++;
@@ -35,6 +46,9 @@ static int midi_playback_open(struct snd_rawmidi_substream *substream)
 
         mutex_unlock(&oxfw->mutex);
 
+        if (err < 0)
+                snd_oxfw_stream_lock_release(oxfw);
+
         return err;
 }
 
@@ -49,6 +63,7 @@ static int midi_capture_close(struct snd_rawmidi_substream *substream)
 
         mutex_unlock(&oxfw->mutex);
 
+        snd_oxfw_stream_lock_release(oxfw);
         return 0;
 }
 
@@ -63,6 +78,7 @@ static int midi_playback_close(struct snd_rawmidi_substream *substream)
 
         mutex_unlock(&oxfw->mutex);
 
+        snd_oxfw_stream_lock_release(oxfw);
         return 0;
 }
 
diff --git a/sound/firewire/oxfw/oxfw-pcm.c b/sound/firewire/oxfw/oxfw-pcm.c
index e84fc9c4bfd1..9bc556b15a92 100644
--- a/sound/firewire/oxfw/oxfw-pcm.c
+++ b/sound/firewire/oxfw/oxfw-pcm.c
@@ -192,10 +192,14 @@ static int pcm_open(struct snd_pcm_substream *substream)
         struct snd_oxfw *oxfw = substream->private_data;
         int err;
 
-        err = init_hw_params(oxfw, substream);
+        err = snd_oxfw_stream_lock_try(oxfw);
         if (err < 0)
                 goto end;
 
+        err = init_hw_params(oxfw, substream);
+        if (err < 0)
+                goto err_locked;
+
         /*
          * When any PCM streams are already running, the available sampling
          * rate is limited at current value.
@@ -210,10 +214,16 @@ static int pcm_open(struct snd_pcm_substream *substream)
         snd_pcm_set_sync(substream);
 end:
         return err;
+err_locked:
+        snd_oxfw_stream_lock_release(oxfw);
+        return err;
 }
 
 static int pcm_close(struct snd_pcm_substream *substream)
 {
+        struct snd_oxfw *oxfw = substream->private_data;
+
+        snd_oxfw_stream_lock_release(oxfw);
         return 0;
 }
 
diff --git a/sound/firewire/oxfw/oxfw-stream.c b/sound/firewire/oxfw/oxfw-stream.c
index a38b3c36faca..b77cf80f1678 100644
--- a/sound/firewire/oxfw/oxfw-stream.c
+++ b/sound/firewire/oxfw/oxfw-stream.c
@@ -644,3 +644,42 @@ int snd_oxfw_stream_discover(struct snd_oxfw *oxfw)
 end:
         return err;
 }
+
+void snd_oxfw_stream_lock_changed(struct snd_oxfw *oxfw)
+{
+        oxfw->dev_lock_changed = true;
+        wake_up(&oxfw->hwdep_wait);
+}
+
+int snd_oxfw_stream_lock_try(struct snd_oxfw *oxfw)
+{
+        int err;
+
+        spin_lock_irq(&oxfw->lock);
+
+        /* user land lock this */
+        if (oxfw->dev_lock_count < 0) {
+                err = -EBUSY;
+                goto end;
+        }
+
+        /* this is the first time */
+        if (oxfw->dev_lock_count++ == 0)
+                snd_oxfw_stream_lock_changed(oxfw);
+        err = 0;
+end:
+        spin_unlock_irq(&oxfw->lock);
+        return err;
+}
+
+void snd_oxfw_stream_lock_release(struct snd_oxfw *oxfw)
+{
+        spin_lock_irq(&oxfw->lock);
+
+        if (WARN_ON(oxfw->dev_lock_count <= 0))
+                goto end;
+        if (--oxfw->dev_lock_count == 0)
+                snd_oxfw_stream_lock_changed(oxfw);
+end:
+        spin_unlock_irq(&oxfw->lock);
+}
diff --git a/sound/firewire/oxfw/oxfw.c b/sound/firewire/oxfw/oxfw.c
index 9cfbfb168dac..cf1d0b55e827 100644
--- a/sound/firewire/oxfw/oxfw.c
+++ b/sound/firewire/oxfw/oxfw.c
@@ -139,6 +139,7 @@ static int oxfw_probe(struct fw_unit *unit,
         oxfw->unit = unit;
         oxfw->device_info = (const struct device_info *)id->driver_data;
         spin_lock_init(&oxfw->lock);
+        init_waitqueue_head(&oxfw->hwdep_wait);
 
         err = snd_oxfw_stream_discover(oxfw);
         if (err < 0)
@@ -164,6 +165,10 @@ static int oxfw_probe(struct fw_unit *unit,
         if (err < 0)
                 goto error;
 
+        err = snd_oxfw_create_hwdep(oxfw);
+        if (err < 0)
+                goto error;
+
         err = snd_oxfw_stream_init_simplex(oxfw, &oxfw->rx_stream);
         if (err < 0)
                 goto error;
diff --git a/sound/firewire/oxfw/oxfw.h b/sound/firewire/oxfw/oxfw.h
index 83a54fc73a11..cace5ad4fe76 100644
--- a/sound/firewire/oxfw/oxfw.h
+++ b/sound/firewire/oxfw/oxfw.h
@@ -12,6 +12,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/compat.h>
 
 #include <sound/control.h>
 #include <sound/core.h>
@@ -20,6 +21,8 @@
 #include <sound/pcm_params.h>
 #include <sound/info.h>
 #include <sound/rawmidi.h>
+#include <sound/firewire.h>
+#include <sound/hwdep.h>
 
 #include "../lib.h"
 #include "../fcp.h"
@@ -64,6 +67,10 @@ struct snd_oxfw {
         s16 volume[6];
         s16 volume_min;
         s16 volume_max;
+
+        int dev_lock_count;
+        bool dev_lock_changed;
+        wait_queue_head_t hwdep_wait;
 };
 
 /*
@@ -124,6 +131,10 @@ int snd_oxfw_stream_get_current_formation(struct snd_oxfw *oxfw,
 
 int snd_oxfw_stream_discover(struct snd_oxfw *oxfw);
 
+void snd_oxfw_stream_lock_changed(struct snd_oxfw *oxfw);
+int snd_oxfw_stream_lock_try(struct snd_oxfw *oxfw);
+void snd_oxfw_stream_lock_release(struct snd_oxfw *oxfw);
+
 int snd_oxfw_create_pcm(struct snd_oxfw *oxfw);
 
 int snd_oxfw_create_mixer(struct snd_oxfw *oxfw);
@@ -131,3 +142,5 @@ int snd_oxfw_create_mixer(struct snd_oxfw *oxfw);
 void snd_oxfw_proc_init(struct snd_oxfw *oxfw);
 
 int snd_oxfw_create_midi(struct snd_oxfw *oxfw);
+
+int snd_oxfw_create_hwdep(struct snd_oxfw *oxfw);