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Commit c631d03c authored by Takashi Iwai's avatar Takashi Iwai
Browse files

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: default avatarTakashi Iwai <tiwai@suse.de>
parent 326ba501

sound/drivers/dummy.c

+272 −141
Original line number Diff line number Diff line
@@ -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 enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0}; 
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_param_array(pcm_substreams, int, NULL, 0444); 
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 @@ static struct platform_device *devices[SNDRV_CARDS]; 
#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_dummy_pcm { 
	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);

	spin_unlock(&dpcm->lock);

	return 0;

}



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)

static int dummy_systimer_stop(struct snd_pcm_substream *substream)

{

	struct snd_pcm_runtime *runtime = substream->runtime;

	struct snd_dummy_pcm *dpcm = runtime->private_data;

	int err = 0;



	struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;

	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;

	}

	del_timer(&dpcm->timer);

	spin_unlock(&dpcm->lock);

	return 0;

}



static int snd_card_dummy_pcm_prepare(struct snd_pcm_substream *substream)

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 @@ static int snd_card_dummy_pcm_prepare(struct snd_pcm_substream *substream) 
	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);
@@ -272,36 +274,212 @@ static void snd_card_dummy_pcm_timer_function(unsigned long data) 
		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),

	.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,

	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 struct snd_pcm_hardware snd_card_dummy_capture =

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)

{

	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |

				 SNDRV_PCM_INFO_RESUME | SNDRV_PCM_INFO_MMAP_VALID),

	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,
@@ -316,117 +494,70 @@ static struct snd_pcm_hardware snd_card_dummy_capture = 
	.fifo_size =		0,

};



static void snd_card_dummy_runtime_free(struct snd_pcm_runtime *runtime)

{

	kfree(runtime->private_data);

}



static int snd_card_dummy_hw_params(struct snd_pcm_substream *substream,

static int dummy_pcm_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));

	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)

{

	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)

static int dummy_pcm_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;

	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);

	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;



	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 = 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_capture_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_playback_close(struct snd_pcm_substream *substream)

{

	return 0;

}



static int snd_card_dummy_capture_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 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,

static struct snd_pcm_ops dummy_pcm_ops = {

	.open =		dummy_pcm_open,

	.close =	dummy_pcm_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,

	.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 @@ static int __devinit snd_card_dummy_pcm(struct snd_dummy *dummy, int device, 
	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");