ALSA: dummy - Support high-res timer mode
Allow snd-dummy driver to use high-res timer as its timing source
instead of the system timer. The new module option "hrtimer" is added
to turn on/off the high-res timer support. It can be switched even
dynamically via sysfs.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c
index 54239d2..f387d53 100644
--- a/sound/drivers/dummy.c
+++ b/sound/drivers/dummy.c
@@ -25,6 +25,8 @@
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/wait.h>
+#include <linux/hrtimer.h>
+#include <linux/math64.h>
#include <linux/moduleparam.h>
#include <sound/core.h>
#include <sound/control.h>
@@ -148,6 +150,9 @@
static int pcm_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
//static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};
+#ifdef CONFIG_HIGH_RES_TIMERS
+static int hrtimer = 1;
+#endif
module_param_array(index, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for dummy soundcard.");
@@ -161,6 +166,10 @@
MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-16) for dummy driver.");
//module_param_array(midi_devs, int, NULL, 0444);
//MODULE_PARM_DESC(midi_devs, "MIDI devices # (0-2) for dummy driver.");
+#ifdef CONFIG_HIGH_RES_TIMERS
+module_param(hrtimer, bool, 0644);
+MODULE_PARM_DESC(hrtimer, "Use hrtimer as the timer source.");
+#endif
static struct platform_device *devices[SNDRV_CARDS];
@@ -171,16 +180,29 @@
#define MIXER_ADDR_CD 4
#define MIXER_ADDR_LAST 4
+struct dummy_timer_ops {
+ int (*create)(struct snd_pcm_substream *);
+ void (*free)(struct snd_pcm_substream *);
+ int (*prepare)(struct snd_pcm_substream *);
+ int (*start)(struct snd_pcm_substream *);
+ int (*stop)(struct snd_pcm_substream *);
+ snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *);
+};
+
struct snd_dummy {
struct snd_card *card;
struct snd_pcm *pcm;
spinlock_t mixer_lock;
int mixer_volume[MIXER_ADDR_LAST+1][2];
int capture_source[MIXER_ADDR_LAST+1][2];
+ const struct dummy_timer_ops *timer_ops;
};
-struct snd_dummy_pcm {
- struct snd_dummy *dummy;
+/*
+ * system timer interface
+ */
+
+struct dummy_systimer_pcm {
spinlock_t lock;
struct timer_list timer;
unsigned int pcm_buffer_size;
@@ -192,46 +214,29 @@
struct snd_pcm_substream *substream;
};
-
-static inline void snd_card_dummy_pcm_timer_start(struct snd_dummy_pcm *dpcm)
+static int dummy_systimer_start(struct snd_pcm_substream *substream)
{
+ struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
+ spin_lock(&dpcm->lock);
dpcm->timer.expires = 1 + jiffies;
add_timer(&dpcm->timer);
-}
-
-static inline void snd_card_dummy_pcm_timer_stop(struct snd_dummy_pcm *dpcm)
-{
- del_timer(&dpcm->timer);
-}
-
-static int snd_card_dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
-{
- struct snd_pcm_runtime *runtime = substream->runtime;
- struct snd_dummy_pcm *dpcm = runtime->private_data;
- int err = 0;
-
- spin_lock(&dpcm->lock);
- switch (cmd) {
- case SNDRV_PCM_TRIGGER_START:
- case SNDRV_PCM_TRIGGER_RESUME:
- snd_card_dummy_pcm_timer_start(dpcm);
- break;
- case SNDRV_PCM_TRIGGER_STOP:
- case SNDRV_PCM_TRIGGER_SUSPEND:
- snd_card_dummy_pcm_timer_stop(dpcm);
- break;
- default:
- err = -EINVAL;
- break;
- }
spin_unlock(&dpcm->lock);
return 0;
}
-static int snd_card_dummy_pcm_prepare(struct snd_pcm_substream *substream)
+static int dummy_systimer_stop(struct snd_pcm_substream *substream)
+{
+ struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
+ spin_lock(&dpcm->lock);
+ del_timer(&dpcm->timer);
+ spin_unlock(&dpcm->lock);
+ return 0;
+}
+
+static int dummy_systimer_prepare(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
- struct snd_dummy_pcm *dpcm = runtime->private_data;
+ struct dummy_systimer_pcm *dpcm = runtime->private_data;
int bps;
bps = snd_pcm_format_width(runtime->format) * runtime->rate *
@@ -247,15 +252,12 @@
dpcm->pcm_irq_pos = 0;
dpcm->pcm_buf_pos = 0;
- snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
- bytes_to_samples(runtime, runtime->dma_bytes));
-
return 0;
}
-static void snd_card_dummy_pcm_timer_function(unsigned long data)
+static void dummy_systimer_callback(unsigned long data)
{
- struct snd_dummy_pcm *dpcm = (struct snd_dummy_pcm *)data;
+ struct dummy_systimer_pcm *dpcm = (struct dummy_systimer_pcm *)data;
unsigned long flags;
spin_lock_irqsave(&dpcm->lock, flags);
@@ -272,18 +274,212 @@
spin_unlock_irqrestore(&dpcm->lock, flags);
}
-static snd_pcm_uframes_t snd_card_dummy_pcm_pointer(struct snd_pcm_substream *substream)
+static snd_pcm_uframes_t
+dummy_systimer_pointer(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
- struct snd_dummy_pcm *dpcm = runtime->private_data;
+ struct dummy_systimer_pcm *dpcm = runtime->private_data;
return bytes_to_frames(runtime, dpcm->pcm_buf_pos / dpcm->pcm_hz);
}
-static struct snd_pcm_hardware snd_card_dummy_playback =
+static int dummy_systimer_create(struct snd_pcm_substream *substream)
{
- .info = (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
- SNDRV_PCM_INFO_RESUME | SNDRV_PCM_INFO_MMAP_VALID),
+ struct dummy_systimer_pcm *dpcm;
+
+ dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
+ if (!dpcm)
+ return -ENOMEM;
+ substream->runtime->private_data = dpcm;
+ init_timer(&dpcm->timer);
+ dpcm->timer.data = (unsigned long) dpcm;
+ dpcm->timer.function = dummy_systimer_callback;
+ spin_lock_init(&dpcm->lock);
+ dpcm->substream = substream;
+ return 0;
+}
+
+static void dummy_systimer_free(struct snd_pcm_substream *substream)
+{
+ kfree(substream->runtime->private_data);
+}
+
+static struct dummy_timer_ops dummy_systimer_ops = {
+ .create = dummy_systimer_create,
+ .free = dummy_systimer_free,
+ .prepare = dummy_systimer_prepare,
+ .start = dummy_systimer_start,
+ .stop = dummy_systimer_stop,
+ .pointer = dummy_systimer_pointer,
+};
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+/*
+ * hrtimer interface
+ */
+
+struct dummy_hrtimer_pcm {
+ ktime_t base_time;
+ ktime_t period_time;
+ atomic_t running;
+ struct hrtimer timer;
+ struct tasklet_struct tasklet;
+ struct snd_pcm_substream *substream;
+};
+
+static void dummy_hrtimer_pcm_elapsed(unsigned long priv)
+{
+ struct dummy_hrtimer_pcm *dpcm = (struct dummy_hrtimer_pcm *)priv;
+ if (atomic_read(&dpcm->running))
+ snd_pcm_period_elapsed(dpcm->substream);
+}
+
+static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer)
+{
+ struct dummy_hrtimer_pcm *dpcm;
+
+ dpcm = container_of(timer, struct dummy_hrtimer_pcm, timer);
+ if (!atomic_read(&dpcm->running))
+ return HRTIMER_NORESTART;
+ tasklet_schedule(&dpcm->tasklet);
+ hrtimer_forward_now(timer, dpcm->period_time);
+ return HRTIMER_RESTART;
+}
+
+static int dummy_hrtimer_start(struct snd_pcm_substream *substream)
+{
+ struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
+
+ dpcm->base_time = hrtimer_cb_get_time(&dpcm->timer);
+ hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL);
+ atomic_set(&dpcm->running, 1);
+ return 0;
+}
+
+static int dummy_hrtimer_stop(struct snd_pcm_substream *substream)
+{
+ struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
+
+ atomic_set(&dpcm->running, 0);
+ hrtimer_cancel(&dpcm->timer);
+ return 0;
+}
+
+static inline void dummy_hrtimer_sync(struct dummy_hrtimer_pcm *dpcm)
+{
+ tasklet_kill(&dpcm->tasklet);
+}
+
+static snd_pcm_uframes_t
+dummy_hrtimer_pointer(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
+ u64 delta;
+ u32 pos;
+
+ delta = ktime_us_delta(hrtimer_cb_get_time(&dpcm->timer),
+ dpcm->base_time);
+ delta = div_u64(delta * runtime->rate + 999999, 1000000);
+ div_u64_rem(delta, runtime->buffer_size, &pos);
+ return pos;
+}
+
+static int dummy_hrtimer_prepare(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
+ unsigned int period, rate;
+ long sec;
+ unsigned long nsecs;
+
+ dummy_hrtimer_sync(dpcm);
+ period = runtime->period_size;
+ rate = runtime->rate;
+ sec = period / rate;
+ period %= rate;
+ nsecs = div_u64((u64)period * 1000000000UL + rate - 1, rate);
+ dpcm->period_time = ktime_set(sec, nsecs);
+
+ return 0;
+}
+
+static int dummy_hrtimer_create(struct snd_pcm_substream *substream)
+{
+ struct dummy_hrtimer_pcm *dpcm;
+
+ dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
+ if (!dpcm)
+ return -ENOMEM;
+ substream->runtime->private_data = dpcm;
+ hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ dpcm->timer.function = dummy_hrtimer_callback;
+ dpcm->substream = substream;
+ atomic_set(&dpcm->running, 0);
+ tasklet_init(&dpcm->tasklet, dummy_hrtimer_pcm_elapsed,
+ (unsigned long)dpcm);
+ return 0;
+}
+
+static void dummy_hrtimer_free(struct snd_pcm_substream *substream)
+{
+ struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
+ dummy_hrtimer_sync(dpcm);
+ kfree(dpcm);
+}
+
+static struct dummy_timer_ops dummy_hrtimer_ops = {
+ .create = dummy_hrtimer_create,
+ .free = dummy_hrtimer_free,
+ .prepare = dummy_hrtimer_prepare,
+ .start = dummy_hrtimer_start,
+ .stop = dummy_hrtimer_stop,
+ .pointer = dummy_hrtimer_pointer,
+};
+
+#endif /* CONFIG_HIGH_RES_TIMERS */
+
+/*
+ * PCM interface
+ */
+
+static int dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+ struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ return dummy->timer_ops->start(substream);
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ return dummy->timer_ops->stop(substream);
+ }
+ return -EINVAL;
+}
+
+static int dummy_pcm_prepare(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
+
+ snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
+ bytes_to_samples(runtime, runtime->dma_bytes));
+ return dummy->timer_ops->prepare(substream);
+}
+
+static snd_pcm_uframes_t dummy_pcm_pointer(struct snd_pcm_substream *substream)
+{
+ struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
+
+ return dummy->timer_ops->pointer(substream);
+}
+
+static struct snd_pcm_hardware dummy_pcm_hardware = {
+ .info = (SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_INTERLEAVED |
+ SNDRV_PCM_INFO_RESUME |
+ SNDRV_PCM_INFO_MMAP_VALID),
.formats = USE_FORMATS,
.rates = USE_RATE,
.rate_min = USE_RATE_MIN,
@@ -298,135 +494,70 @@
.fifo_size = 0,
};
-static struct snd_pcm_hardware snd_card_dummy_capture =
+static int dummy_pcm_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *hw_params)
{
- .info = (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
- SNDRV_PCM_INFO_RESUME | SNDRV_PCM_INFO_MMAP_VALID),
- .formats = USE_FORMATS,
- .rates = USE_RATE,
- .rate_min = USE_RATE_MIN,
- .rate_max = USE_RATE_MAX,
- .channels_min = USE_CHANNELS_MIN,
- .channels_max = USE_CHANNELS_MAX,
- .buffer_bytes_max = MAX_BUFFER_SIZE,
- .period_bytes_min = 64,
- .period_bytes_max = MAX_PERIOD_SIZE,
- .periods_min = USE_PERIODS_MIN,
- .periods_max = USE_PERIODS_MAX,
- .fifo_size = 0,
-};
-
-static void snd_card_dummy_runtime_free(struct snd_pcm_runtime *runtime)
-{
- kfree(runtime->private_data);
+ return snd_pcm_lib_malloc_pages(substream,
+ params_buffer_bytes(hw_params));
}
-static int snd_card_dummy_hw_params(struct snd_pcm_substream *substream,
- struct snd_pcm_hw_params *hw_params)
-{
- return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
-}
-
-static int snd_card_dummy_hw_free(struct snd_pcm_substream *substream)
+static int dummy_pcm_hw_free(struct snd_pcm_substream *substream)
{
return snd_pcm_lib_free_pages(substream);
}
-static struct snd_dummy_pcm *new_pcm_stream(struct snd_pcm_substream *substream)
+static int dummy_pcm_open(struct snd_pcm_substream *substream)
{
- struct snd_dummy_pcm *dpcm;
-
- dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
- if (! dpcm)
- return dpcm;
- init_timer(&dpcm->timer);
- dpcm->timer.data = (unsigned long) dpcm;
- dpcm->timer.function = snd_card_dummy_pcm_timer_function;
- spin_lock_init(&dpcm->lock);
- dpcm->substream = substream;
- return dpcm;
-}
-
-static int snd_card_dummy_playback_open(struct snd_pcm_substream *substream)
-{
+ struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
- struct snd_dummy_pcm *dpcm;
int err;
- if ((dpcm = new_pcm_stream(substream)) == NULL)
- return -ENOMEM;
- runtime->private_data = dpcm;
- /* makes the infrastructure responsible for freeing dpcm */
- runtime->private_free = snd_card_dummy_runtime_free;
- runtime->hw = snd_card_dummy_playback;
+ dummy->timer_ops = &dummy_systimer_ops;
+#ifdef CONFIG_HIGH_RES_TIMERS
+ if (hrtimer)
+ dummy->timer_ops = &dummy_hrtimer_ops;
+#endif
+
+ err = dummy->timer_ops->create(substream);
+ if (err < 0)
+ return err;
+
+ runtime->hw = dummy_pcm_hardware;
if (substream->pcm->device & 1) {
runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
}
if (substream->pcm->device & 2)
- runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP|SNDRV_PCM_INFO_MMAP_VALID);
- err = add_playback_constraints(runtime);
- if (err < 0)
+ runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_MMAP_VALID);
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ err = add_playback_constraints(substream->runtime);
+ else
+ err = add_capture_constraints(substream->runtime);
+ if (err < 0) {
+ dummy->timer_ops->free(substream);
return err;
-
- return 0;
-}
-
-static int snd_card_dummy_capture_open(struct snd_pcm_substream *substream)
-{
- struct snd_pcm_runtime *runtime = substream->runtime;
- struct snd_dummy_pcm *dpcm;
- int err;
-
- if ((dpcm = new_pcm_stream(substream)) == NULL)
- return -ENOMEM;
- runtime->private_data = dpcm;
- /* makes the infrastructure responsible for freeing dpcm */
- runtime->private_free = snd_card_dummy_runtime_free;
- runtime->hw = snd_card_dummy_capture;
- if (substream->pcm->device == 1) {
- runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
- runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
}
- if (substream->pcm->device & 2)
- runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP|SNDRV_PCM_INFO_MMAP_VALID);
- err = add_capture_constraints(runtime);
- if (err < 0)
- return err;
-
return 0;
}
-static int snd_card_dummy_playback_close(struct snd_pcm_substream *substream)
+static int dummy_pcm_close(struct snd_pcm_substream *substream)
{
+ struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
+ dummy->timer_ops->free(substream);
return 0;
}
-static int snd_card_dummy_capture_close(struct snd_pcm_substream *substream)
-{
- return 0;
-}
-
-static struct snd_pcm_ops snd_card_dummy_playback_ops = {
- .open = snd_card_dummy_playback_open,
- .close = snd_card_dummy_playback_close,
- .ioctl = snd_pcm_lib_ioctl,
- .hw_params = snd_card_dummy_hw_params,
- .hw_free = snd_card_dummy_hw_free,
- .prepare = snd_card_dummy_pcm_prepare,
- .trigger = snd_card_dummy_pcm_trigger,
- .pointer = snd_card_dummy_pcm_pointer,
-};
-
-static struct snd_pcm_ops snd_card_dummy_capture_ops = {
- .open = snd_card_dummy_capture_open,
- .close = snd_card_dummy_capture_close,
- .ioctl = snd_pcm_lib_ioctl,
- .hw_params = snd_card_dummy_hw_params,
- .hw_free = snd_card_dummy_hw_free,
- .prepare = snd_card_dummy_pcm_prepare,
- .trigger = snd_card_dummy_pcm_trigger,
- .pointer = snd_card_dummy_pcm_pointer,
+static struct snd_pcm_ops dummy_pcm_ops = {
+ .open = dummy_pcm_open,
+ .close = dummy_pcm_close,
+ .ioctl = snd_pcm_lib_ioctl,
+ .hw_params = dummy_pcm_hw_params,
+ .hw_free = dummy_pcm_hw_free,
+ .prepare = dummy_pcm_prepare,
+ .trigger = dummy_pcm_trigger,
+ .pointer = dummy_pcm_pointer,
};
static int __devinit snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
@@ -440,8 +571,8 @@
if (err < 0)
return err;
dummy->pcm = pcm;
- snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_card_dummy_playback_ops);
- snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_card_dummy_capture_ops);
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &dummy_pcm_ops);
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &dummy_pcm_ops);
pcm->private_data = dummy;
pcm->info_flags = 0;
strcpy(pcm->name, "Dummy PCM");