1 files changed, 89 insertions, 0 deletions
diff --git a/sound/pci/emu10k1/timer.c b/sound/pci/emu10k1/timer.c
new file mode 100644
index 0000000000..bb24783193
--- /dev/null
+++ b/sound/pci/emu10k1/timer.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Lee Revell <rlrevell@joe-job.com>
+ *                   Clemens Ladisch <clemens@ladisch.de>
+ *                   Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
+ *
+ *  Routines for control of EMU10K1 chips
+ */
+
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/emu10k1.h>
+
+static int snd_emu10k1_timer_start(struct snd_timer *timer)
+{
+	struct snd_emu10k1 *emu;
+	unsigned int delay;
+
+	emu = snd_timer_chip(timer);
+	delay = timer->sticks - 1;
+	if (delay < 5 ) /* minimum time is 5 ticks */
+		delay = 5;
+	snd_emu10k1_intr_enable(emu, INTE_INTERVALTIMERENB);
+	outw(delay & TIMER_RATE_MASK, emu->port + TIMER);
+	return 0;
+}
+
+static int snd_emu10k1_timer_stop(struct snd_timer *timer)
+{
+	struct snd_emu10k1 *emu;
+
+	emu = snd_timer_chip(timer);
+	snd_emu10k1_intr_disable(emu, INTE_INTERVALTIMERENB);
+	return 0;
+}
+
+static unsigned long snd_emu10k1_timer_c_resolution(struct snd_timer *timer)
+{
+	struct snd_emu10k1 *emu = snd_timer_chip(timer);
+
+	if (emu->card_capabilities->emu_model &&
+	    emu->emu1010.word_clock == 44100)
+		return 22676;  // 1 sample @ 44.1 kHz = 22.675736...us
+	else
+		return 20833;  // 1 sample @ 48 kHz = 20.833...us
+}
+
+static int snd_emu10k1_timer_precise_resolution(struct snd_timer *timer,
+					       unsigned long *num, unsigned long *den)
+{
+	struct snd_emu10k1 *emu = snd_timer_chip(timer);
+
+	*num = 1;
+	if (emu->card_capabilities->emu_model)
+		*den = emu->emu1010.word_clock;
+	else
+		*den = 48000;
+	return 0;
+}
+
+static const struct snd_timer_hardware snd_emu10k1_timer_hw = {
+	.flags = SNDRV_TIMER_HW_AUTO,
+	.ticks = 1024,
+	.start = snd_emu10k1_timer_start,
+	.stop = snd_emu10k1_timer_stop,
+	.c_resolution = snd_emu10k1_timer_c_resolution,
+	.precise_resolution = snd_emu10k1_timer_precise_resolution,
+};
+
+int snd_emu10k1_timer(struct snd_emu10k1 *emu, int device)
+{
+	struct snd_timer *timer = NULL;
+	struct snd_timer_id tid;
+	int err;
+
+	tid.dev_class = SNDRV_TIMER_CLASS_CARD;
+	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	tid.card = emu->card->number;
+	tid.device = device;
+	tid.subdevice = 0;
+	err = snd_timer_new(emu->card, "EMU10K1", &tid, &timer);
+	if (err >= 0) {
+		strcpy(timer->name, "EMU10K1 timer");
+		timer->private_data = emu;
+		timer->hw = snd_emu10k1_timer_hw;
+	}
+	emu->timer = timer;
+	return err;
+}