1 files changed, 443 insertions, 0 deletions

diff --git a/sound/pci/ctxfi/cttimer.c b/sound/pci/ctxfi/cttimer.c
new file mode 100644
index 00000000..03fb9090
--- /dev/null
+++ b/sound/pci/ctxfi/cttimer.c
@@ -0,0 +1,443 @@
+/*
+ * PCM timer handling on ctxfi
+ *
+ * This source file is released under GPL v2 license (no other versions).
+ * See the COPYING file included in the main directory of this source
+ * distribution for the license terms and conditions.
+ */
+
+#include <linux/slab.h>
+#include <linux/math64.h>
+#include <linux/moduleparam.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include "ctatc.h"
+#include "cthardware.h"
+#include "cttimer.h"
+
+static bool use_system_timer;
+MODULE_PARM_DESC(use_system_timer, "Force to use system-timer");
+module_param(use_system_timer, bool, S_IRUGO);
+
+struct ct_timer_ops {
+	void (*init)(struct ct_timer_instance *);
+	void (*prepare)(struct ct_timer_instance *);
+	void (*start)(struct ct_timer_instance *);
+	void (*stop)(struct ct_timer_instance *);
+	void (*free_instance)(struct ct_timer_instance *);
+	void (*interrupt)(struct ct_timer *);
+	void (*free_global)(struct ct_timer *);
+};
+
+/* timer instance -- assigned to each PCM stream */
+struct ct_timer_instance {
+	spinlock_t lock;
+	struct ct_timer *timer_base;
+	struct ct_atc_pcm *apcm;
+	struct snd_pcm_substream *substream;
+	struct timer_list timer;
+	struct list_head instance_list;
+	struct list_head running_list;
+	unsigned int position;
+	unsigned int frag_count;
+	unsigned int running:1;
+	unsigned int need_update:1;
+};
+
+/* timer instance manager */
+struct ct_timer {
+	spinlock_t lock;		/* global timer lock (for xfitimer) */
+	spinlock_t list_lock;		/* lock for instance list */
+	struct ct_atc *atc;
+	struct ct_timer_ops *ops;
+	struct list_head instance_head;
+	struct list_head running_head;
+	unsigned int wc;		/* current wallclock */
+	unsigned int irq_handling:1;	/* in IRQ handling */
+	unsigned int reprogram:1;	/* need to reprogram the internval */
+	unsigned int running:1;		/* global timer running */
+};
+
+
+/*
+ * system-timer-based updates
+ */
+
+static void ct_systimer_callback(unsigned long data)
+{
+	struct ct_timer_instance *ti = (struct ct_timer_instance *)data;
+	struct snd_pcm_substream *substream = ti->substream;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct ct_atc_pcm *apcm = ti->apcm;
+	unsigned int period_size = runtime->period_size;
+	unsigned int buffer_size = runtime->buffer_size;
+	unsigned long flags;
+	unsigned int position, dist, interval;
+
+	position = substream->ops->pointer(substream);
+	dist = (position + buffer_size - ti->position) % buffer_size;
+	if (dist >= period_size ||
+	    position / period_size != ti->position / period_size) {
+		apcm->interrupt(apcm);
+		ti->position = position;
+	}
+	/* Add extra HZ*5/1000 to avoid overrun issue when recording
+	 * at 8kHz in 8-bit format or at 88kHz in 24-bit format. */
+	interval = ((period_size - (position % period_size))
+		   * HZ + (runtime->rate - 1)) / runtime->rate + HZ * 5 / 1000;
+	spin_lock_irqsave(&ti->lock, flags);
+	if (ti->running)
+		mod_timer(&ti->timer, jiffies + interval);
+	spin_unlock_irqrestore(&ti->lock, flags);
+}
+
+static void ct_systimer_init(struct ct_timer_instance *ti)
+{
+	setup_timer(&ti->timer, ct_systimer_callback,
+		    (unsigned long)ti);
+}
+
+static void ct_systimer_start(struct ct_timer_instance *ti)
+{
+	struct snd_pcm_runtime *runtime = ti->substream->runtime;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ti->lock, flags);
+	ti->running = 1;
+	mod_timer(&ti->timer,
+		  jiffies + (runtime->period_size * HZ +
+			     (runtime->rate - 1)) / runtime->rate);
+	spin_unlock_irqrestore(&ti->lock, flags);
+}
+
+static void ct_systimer_stop(struct ct_timer_instance *ti)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ti->lock, flags);
+	ti->running = 0;
+	del_timer(&ti->timer);
+	spin_unlock_irqrestore(&ti->lock, flags);
+}
+
+static void ct_systimer_prepare(struct ct_timer_instance *ti)
+{
+	ct_systimer_stop(ti);
+	try_to_del_timer_sync(&ti->timer);
+}
+
+#define ct_systimer_free	ct_systimer_prepare
+
+static struct ct_timer_ops ct_systimer_ops = {
+	.init = ct_systimer_init,
+	.free_instance = ct_systimer_free,
+	.prepare = ct_systimer_prepare,
+	.start = ct_systimer_start,
+	.stop = ct_systimer_stop,
+};
+
+
+/*
+ * Handling multiple streams using a global emu20k1 timer irq
+ */
+
+#define CT_TIMER_FREQ	48000
+#define MIN_TICKS	1
+#define MAX_TICKS	((1 << 13) - 1)
+
+static void ct_xfitimer_irq_rearm(struct ct_timer *atimer, int ticks)
+{
+	struct hw *hw = atimer->atc->hw;
+	if (ticks > MAX_TICKS)
+		ticks = MAX_TICKS;
+	hw->set_timer_tick(hw, ticks);
+	if (!atimer->running)
+		hw->set_timer_irq(hw, 1);
+	atimer->running = 1;
+}
+
+static void ct_xfitimer_irq_stop(struct ct_timer *atimer)
+{
+	if (atimer->running) {
+		struct hw *hw = atimer->atc->hw;
+		hw->set_timer_irq(hw, 0);
+		hw->set_timer_tick(hw, 0);
+		atimer->running = 0;
+	}
+}
+
+static inline unsigned int ct_xfitimer_get_wc(struct ct_timer *atimer)
+{
+	struct hw *hw = atimer->atc->hw;
+	return hw->get_wc(hw);
+}
+
+/*
+ * reprogram the timer interval;
+ * checks the running instance list and determines the next timer interval.
+ * also updates the each stream position, returns the number of streams
+ * to call snd_pcm_period_elapsed() appropriately
+ *
+ * call this inside the lock and irq disabled
+ */
+static int ct_xfitimer_reprogram(struct ct_timer *atimer, int can_update)
+{
+	struct ct_timer_instance *ti;
+	unsigned int min_intr = (unsigned int)-1;
+	int updates = 0;
+	unsigned int wc, diff;
+
+	if (list_empty(&atimer->running_head)) {
+		ct_xfitimer_irq_stop(atimer);
+		atimer->reprogram = 0; /* clear flag */
+		return 0;
+	}
+
+	wc = ct_xfitimer_get_wc(atimer);
+	diff = wc - atimer->wc;
+	atimer->wc = wc;
+	list_for_each_entry(ti, &atimer->running_head, running_list) {
+		if (ti->frag_count > diff)
+			ti->frag_count -= diff;
+		else {
+			unsigned int pos;
+			unsigned int period_size, rate;
+
+			period_size = ti->substream->runtime->period_size;
+			rate = ti->substream->runtime->rate;
+			pos = ti->substream->ops->pointer(ti->substream);
+			if (pos / period_size != ti->position / period_size) {
+				ti->need_update = 1;
+				ti->position = pos;
+				updates++;
+			}
+			pos %= period_size;
+			pos = period_size - pos;
+			ti->frag_count = div_u64((u64)pos * CT_TIMER_FREQ +
+						 rate - 1, rate);
+		}
+		if (ti->need_update && !can_update)
+			min_intr = 0; /* pending to the next irq */
+		if (ti->frag_count < min_intr)
+			min_intr = ti->frag_count;
+	}
+
+	if (min_intr < MIN_TICKS)
+		min_intr = MIN_TICKS;
+	ct_xfitimer_irq_rearm(atimer, min_intr);
+	atimer->reprogram = 0; /* clear flag */
+	return updates;
+}
+
+/* look through the instance list and call period_elapsed if needed */
+static void ct_xfitimer_check_period(struct ct_timer *atimer)
+{
+	struct ct_timer_instance *ti;
+	unsigned long flags;
+
+	spin_lock_irqsave(&atimer->list_lock, flags);
+	list_for_each_entry(ti, &atimer->instance_head, instance_list) {
+		if (ti->running && ti->need_update) {
+			ti->need_update = 0;
+			ti->apcm->interrupt(ti->apcm);
+		}
+	}
+	spin_unlock_irqrestore(&atimer->list_lock, flags);
+}
+
+/* Handle timer-interrupt */
+static void ct_xfitimer_callback(struct ct_timer *atimer)
+{
+	int update;
+	unsigned long flags;
+
+	spin_lock_irqsave(&atimer->lock, flags);
+	atimer->irq_handling = 1;
+	do {
+		update = ct_xfitimer_reprogram(atimer, 1);
+		spin_unlock(&atimer->lock);
+		if (update)
+			ct_xfitimer_check_period(atimer);
+		spin_lock(&atimer->lock);
+	} while (atimer->reprogram);
+	atimer->irq_handling = 0;
+	spin_unlock_irqrestore(&atimer->lock, flags);
+}
+
+static void ct_xfitimer_prepare(struct ct_timer_instance *ti)
+{
+	ti->frag_count = ti->substream->runtime->period_size;
+	ti->running = 0;
+	ti->need_update = 0;
+}
+
+
+/* start/stop the timer */
+static void ct_xfitimer_update(struct ct_timer *atimer)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&atimer->lock, flags);
+	if (atimer->irq_handling) {
+		/* reached from IRQ handler; let it handle later */
+		atimer->reprogram = 1;
+		spin_unlock_irqrestore(&atimer->lock, flags);
+		return;
+	}
+
+	ct_xfitimer_irq_stop(atimer);
+	ct_xfitimer_reprogram(atimer, 0);
+	spin_unlock_irqrestore(&atimer->lock, flags);
+}
+
+static void ct_xfitimer_start(struct ct_timer_instance *ti)
+{
+	struct ct_timer *atimer = ti->timer_base;
+	unsigned long flags;
+
+	spin_lock_irqsave(&atimer->lock, flags);
+	if (list_empty(&ti->running_list))
+		atimer->wc = ct_xfitimer_get_wc(atimer);
+	ti->running = 1;
+	ti->need_update = 0;
+	list_add(&ti->running_list, &atimer->running_head);
+	spin_unlock_irqrestore(&atimer->lock, flags);
+	ct_xfitimer_update(atimer);
+}
+
+static void ct_xfitimer_stop(struct ct_timer_instance *ti)
+{
+	struct ct_timer *atimer = ti->timer_base;
+	unsigned long flags;
+
+	spin_lock_irqsave(&atimer->lock, flags);
+	list_del_init(&ti->running_list);
+	ti->running = 0;
+	spin_unlock_irqrestore(&atimer->lock, flags);
+	ct_xfitimer_update(atimer);
+}
+
+static void ct_xfitimer_free_global(struct ct_timer *atimer)
+{
+	ct_xfitimer_irq_stop(atimer);
+}
+
+static struct ct_timer_ops ct_xfitimer_ops = {
+	.prepare = ct_xfitimer_prepare,
+	.start = ct_xfitimer_start,
+	.stop = ct_xfitimer_stop,
+	.interrupt = ct_xfitimer_callback,
+	.free_global = ct_xfitimer_free_global,
+};
+
+/*
+ * timer instance
+ */
+
+struct ct_timer_instance *
+ct_timer_instance_new(struct ct_timer *atimer, struct ct_atc_pcm *apcm)
+{
+	struct ct_timer_instance *ti;
+
+	ti = kzalloc(sizeof(*ti), GFP_KERNEL);
+	if (!ti)
+		return NULL;
+	spin_lock_init(&ti->lock);
+	INIT_LIST_HEAD(&ti->instance_list);
+	INIT_LIST_HEAD(&ti->running_list);
+	ti->timer_base = atimer;
+	ti->apcm = apcm;
+	ti->substream = apcm->substream;
+	if (atimer->ops->init)
+		atimer->ops->init(ti);
+
+	spin_lock_irq(&atimer->list_lock);
+	list_add(&ti->instance_list, &atimer->instance_head);
+	spin_unlock_irq(&atimer->list_lock);
+
+	return ti;
+}
+
+void ct_timer_prepare(struct ct_timer_instance *ti)
+{
+	if (ti->timer_base->ops->prepare)
+		ti->timer_base->ops->prepare(ti);
+	ti->position = 0;
+	ti->running = 0;
+}
+
+void ct_timer_start(struct ct_timer_instance *ti)
+{
+	struct ct_timer *atimer = ti->timer_base;
+	atimer->ops->start(ti);
+}
+
+void ct_timer_stop(struct ct_timer_instance *ti)
+{
+	struct ct_timer *atimer = ti->timer_base;
+	atimer->ops->stop(ti);
+}
+
+void ct_timer_instance_free(struct ct_timer_instance *ti)
+{
+	struct ct_timer *atimer = ti->timer_base;
+
+	atimer->ops->stop(ti); /* to be sure */
+	if (atimer->ops->free_instance)
+		atimer->ops->free_instance(ti);
+
+	spin_lock_irq(&atimer->list_lock);
+	list_del(&ti->instance_list);
+	spin_unlock_irq(&atimer->list_lock);
+
+	kfree(ti);
+}
+
+/*
+ * timer manager
+ */
+
+static void ct_timer_interrupt(void *data, unsigned int status)
+{
+	struct ct_timer *timer = data;
+
+	/* Interval timer interrupt */
+	if ((status & IT_INT) && timer->ops->interrupt)
+		timer->ops->interrupt(timer);
+}
+
+struct ct_timer *ct_timer_new(struct ct_atc *atc)
+{
+	struct ct_timer *atimer;
+	struct hw *hw;
+
+	atimer = kzalloc(sizeof(*atimer), GFP_KERNEL);
+	if (!atimer)
+		return NULL;
+	spin_lock_init(&atimer->lock);
+	spin_lock_init(&atimer->list_lock);
+	INIT_LIST_HEAD(&atimer->instance_head);
+	INIT_LIST_HEAD(&atimer->running_head);
+	atimer->atc = atc;
+	hw = atc->hw;
+	if (!use_system_timer && hw->set_timer_irq) {
+		snd_printd(KERN_INFO "ctxfi: Use xfi-native timer\n");
+		atimer->ops = &ct_xfitimer_ops;
+		hw->irq_callback_data = atimer;
+		hw->irq_callback = ct_timer_interrupt;
+	} else {
+		snd_printd(KERN_INFO "ctxfi: Use system timer\n");
+		atimer->ops = &ct_systimer_ops;
+	}
+	return atimer;
+}
+
+void ct_timer_free(struct ct_timer *atimer)
+{
+	struct hw *hw = atimer->atc->hw;
+	hw->irq_callback = NULL;
+	if (atimer->ops->free_global)
+		atimer->ops->free_global(atimer);
+	kfree(atimer);
+}
+