ALSA: aloop: Use callback functions for timer specific implementations

This commit only refactors the implementation. It does not change the
behaviour.
It is required to support other timers (e.g sound timer).

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191120174955.6410-4-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
index 7919006..3bfd7c3 100644 (file)
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -55,8 +55,39 @@ MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels change
 
 #define NO_PITCH 100000
 
+struct loopback_cable;
 struct loopback_pcm;
 
+struct loopback_ops {
+       /* optional
+        * call in loopback->cable_lock
+        */
+       int (*open)(struct loopback_pcm *dpcm);
+       /* required
+        * call in cable->lock
+        */
+       int (*start)(struct loopback_pcm *dpcm);
+       /* required
+        * call in cable->lock
+        */
+       int (*stop)(struct loopback_pcm *dpcm);
+       /* optional */
+       int (*stop_sync)(struct loopback_pcm *dpcm);
+       /* optional */
+       int (*close_substream)(struct loopback_pcm *dpcm);
+       /* optional
+        * call in loopback->cable_lock
+        */
+       int (*close_cable)(struct loopback_pcm *dpcm);
+       /* optional
+        * call in cable->lock
+        */
+       unsigned int (*pos_update)(struct loopback_cable *cable);
+       /* optional */
+       void (*dpcm_info)(struct loopback_pcm *dpcm,
+                         struct snd_info_buffer *buffer);
+};
+
 struct loopback_cable {
        spinlock_t lock;
        struct loopback_pcm *streams[2];
@@ -65,6 +96,8 @@ struct loopback_cable {
        unsigned int valid;
        unsigned int running;
        unsigned int pause;
+       /* timer specific */
+       struct loopback_ops *ops;
 };
 
 struct loopback_setup {
@@ -270,7 +303,7 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
                spin_lock(&cable->lock);        
                cable->running |= stream;
                cable->pause &= ~stream;
-               err = loopback_timer_start(dpcm);
+               err = cable->ops->start(dpcm);
                spin_unlock(&cable->lock);
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                        loopback_active_notify(dpcm);
@@ -279,7 +312,7 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
                spin_lock(&cable->lock);        
                cable->running &= ~stream;
                cable->pause &= ~stream;
-               err = loopback_timer_stop(dpcm);
+               err = cable->ops->stop(dpcm);
                spin_unlock(&cable->lock);
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                        loopback_active_notify(dpcm);
@@ -288,7 +321,7 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
        case SNDRV_PCM_TRIGGER_SUSPEND:
                spin_lock(&cable->lock);        
                cable->pause |= stream;
-               err = loopback_timer_stop(dpcm);
+               err = cable->ops->stop(dpcm);
                spin_unlock(&cable->lock);
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                        loopback_active_notify(dpcm);
@@ -298,7 +331,7 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
                spin_lock(&cable->lock);
                dpcm->last_jiffies = jiffies;
                cable->pause &= ~stream;
-               err = loopback_timer_start(dpcm);
+               err = cable->ops->start(dpcm);
                spin_unlock(&cable->lock);
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                        loopback_active_notify(dpcm);
@@ -329,9 +362,11 @@ static int loopback_prepare(struct snd_pcm_substream *substream)
        struct loopback_cable *cable = dpcm->cable;
        int err, bps, salign;
 
-       err = loopback_timer_stop_sync(dpcm);
-       if (err < 0)
-               return err;
+       if (cable->ops->stop_sync) {
+               err = cable->ops->stop_sync(dpcm);
+               if (err < 0)
+                       return err;
+       }
 
        salign = (snd_pcm_format_physical_width(runtime->format) *
                                                runtime->channels) / 8;
@@ -539,6 +574,18 @@ static void loopback_timer_function(struct timer_list *t)
        spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 }
 
+static void loopback_jiffies_timer_dpcm_info(struct loopback_pcm *dpcm,
+                                            struct snd_info_buffer *buffer)
+{
+       snd_iprintf(buffer, "    update_pending:\t%u\n",
+                   dpcm->period_update_pending);
+       snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
+       snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
+       snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
+                   dpcm->last_jiffies, jiffies);
+       snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
+}
+
 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 {
        struct snd_pcm_runtime *runtime = substream->runtime;
@@ -546,7 +593,8 @@ static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
        snd_pcm_uframes_t pos;
 
        spin_lock(&dpcm->cable->lock);
-       loopback_pos_update(dpcm->cable);
+       if (dpcm->cable->ops->pos_update)
+               dpcm->cable->ops->pos_update(dpcm->cable);
        pos = dpcm->buf_pos;
        spin_unlock(&dpcm->cable->lock);
        return bytes_to_frames(runtime, pos);
@@ -671,12 +719,33 @@ static void free_cable(struct snd_pcm_substream *substream)
                cable->streams[substream->stream] = NULL;
                spin_unlock_irq(&cable->lock);
        } else {
+               struct loopback_pcm *dpcm = substream->runtime->private_data;
+
+               if (cable->ops && cable->ops->close_cable && dpcm)
+                       cable->ops->close_cable(dpcm);
                /* free the cable */
                loopback->cables[substream->number][dev] = NULL;
                kfree(cable);
        }
 }
 
+static int loopback_jiffies_timer_open(struct loopback_pcm *dpcm)
+{
+       timer_setup(&dpcm->timer, loopback_timer_function, 0);
+
+       return 0;
+}
+
+static struct loopback_ops loopback_jiffies_timer_ops = {
+       .open = loopback_jiffies_timer_open,
+       .start = loopback_timer_start,
+       .stop = loopback_timer_stop,
+       .stop_sync = loopback_timer_stop_sync,
+       .close_substream = loopback_timer_stop_sync,
+       .pos_update = loopback_pos_update,
+       .dpcm_info = loopback_jiffies_timer_dpcm_info,
+};
+
 static int loopback_open(struct snd_pcm_substream *substream)
 {
        struct snd_pcm_runtime *runtime = substream->runtime;
@@ -694,7 +763,6 @@ static int loopback_open(struct snd_pcm_substream *substream)
        }
        dpcm->loopback = loopback;
        dpcm->substream = substream;
-       timer_setup(&dpcm->timer, loopback_timer_function, 0);
 
        cable = loopback->cables[substream->number][dev];
        if (!cable) {
@@ -705,9 +773,17 @@ static int loopback_open(struct snd_pcm_substream *substream)
                }
                spin_lock_init(&cable->lock);
                cable->hw = loopback_pcm_hardware;
+               cable->ops = &loopback_jiffies_timer_ops;
                loopback->cables[substream->number][dev] = cable;
        }
        dpcm->cable = cable;
+       runtime->private_data = dpcm;
+
+       if (cable->ops->open) {
+               err = cable->ops->open(dpcm);
+               if (err < 0)
+                       goto unlock;
+       }
 
        snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 
@@ -733,7 +809,9 @@ static int loopback_open(struct snd_pcm_substream *substream)
        if (err < 0)
                goto unlock;
 
-       runtime->private_data = dpcm;
+       /* loopback_runtime_free() has not to be called if kfree(dpcm) was
+        * already called here. Otherwise it will end up with a double free.
+        */
        runtime->private_free = loopback_runtime_free;
        if (get_notify(dpcm))
                runtime->hw = loopback_pcm_hardware;
@@ -757,12 +835,14 @@ static int loopback_close(struct snd_pcm_substream *substream)
 {
        struct loopback *loopback = substream->private_data;
        struct loopback_pcm *dpcm = substream->runtime->private_data;
+       int err = 0;
 
-       loopback_timer_stop_sync(dpcm);
+       if (dpcm->cable->ops->close_substream)
+               err = dpcm->cable->ops->close_substream(dpcm);
        mutex_lock(&loopback->cable_lock);
        free_cable(substream);
        mutex_unlock(&loopback->cable_lock);
-       return 0;
+       return err;
 }
 
 static const struct snd_pcm_ops loopback_pcm_ops = {
@@ -1086,13 +1166,8 @@ static void print_dpcm_info(struct snd_info_buffer *buffer,
        snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
        snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
        snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
-       snd_iprintf(buffer, "    update_pending:\t%u\n",
-                                               dpcm->period_update_pending);
-       snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
-       snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
-       snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
-                                       dpcm->last_jiffies, jiffies);
-       snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
+       if (dpcm->cable->ops->dpcm_info)
+               dpcm->cable->ops->dpcm_info(dpcm, buffer);
 }
 
 static void print_substream_info(struct snd_info_buffer *buffer,