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-rw-r--r--arch/m68k/amiga/amisound.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/arch/m68k/amiga/amisound.c b/arch/m68k/amiga/amisound.c
new file mode 100644
index 0000000..cb5d9363
--- /dev/null
+++ b/arch/m68k/amiga/amisound.c
@@ -0,0 +1,113 @@
+/*
+ * linux/arch/m68k/amiga/amisound.c
+ *
+ * amiga sound driver for Linux/m68k
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/config.h>
+#include <linux/jiffies.h>
+#include <linux/timer.h>
+#include <linux/init.h>
+#include <linux/string.h>
+
+#include <asm/system.h>
+#include <asm/amigahw.h>
+
+static unsigned short *snd_data;
+static const signed char sine_data[] = {
+ 0, 39, 75, 103, 121, 127, 121, 103, 75, 39,
+ 0, -39, -75, -103, -121, -127, -121, -103, -75, -39
+};
+#define DATA_SIZE (sizeof(sine_data)/sizeof(sine_data[0]))
+
+ /*
+ * The minimum period for audio may be modified by the frame buffer
+ * device since it depends on htotal (for OCS/ECS/AGA)
+ */
+
+volatile unsigned short amiga_audio_min_period = 124; /* Default for pre-OCS */
+
+#define MAX_PERIOD (65535)
+
+
+ /*
+ * Current period (set by dmasound.c)
+ */
+
+unsigned short amiga_audio_period = MAX_PERIOD;
+
+static unsigned long clock_constant;
+
+void __init amiga_init_sound(void)
+{
+ static struct resource beep_res = { .name = "Beep" };
+
+ snd_data = amiga_chip_alloc_res(sizeof(sine_data), &beep_res);
+ if (!snd_data) {
+ printk (KERN_CRIT "amiga init_sound: failed to allocate chipmem\n");
+ return;
+ }
+ memcpy (snd_data, sine_data, sizeof(sine_data));
+
+ /* setup divisor */
+ clock_constant = (amiga_colorclock+DATA_SIZE/2)/DATA_SIZE;
+
+ /* without amifb, turn video off and enable high quality sound */
+#ifndef CONFIG_FB_AMIGA
+ amifb_video_off();
+#endif
+}
+
+static void nosound( unsigned long ignored );
+static struct timer_list sound_timer = TIMER_INITIALIZER(nosound, 0, 0);
+
+void amiga_mksound( unsigned int hz, unsigned int ticks )
+{
+ unsigned long flags;
+
+ if (!snd_data)
+ return;
+
+ local_irq_save(flags);
+ del_timer( &sound_timer );
+
+ if (hz > 20 && hz < 32767) {
+ unsigned long period = (clock_constant / hz);
+
+ if (period < amiga_audio_min_period)
+ period = amiga_audio_min_period;
+ if (period > MAX_PERIOD)
+ period = MAX_PERIOD;
+
+ /* setup pointer to data, period, length and volume */
+ custom.aud[2].audlc = snd_data;
+ custom.aud[2].audlen = sizeof(sine_data)/2;
+ custom.aud[2].audper = (unsigned short)period;
+ custom.aud[2].audvol = 32; /* 50% of maxvol */
+
+ if (ticks) {
+ sound_timer.expires = jiffies + ticks;
+ add_timer( &sound_timer );
+ }
+
+ /* turn on DMA for audio channel 2 */
+ custom.dmacon = DMAF_SETCLR | DMAF_AUD2;
+
+ } else
+ nosound( 0 );
+
+ local_irq_restore(flags);
+}
+
+
+static void nosound( unsigned long ignored )
+{
+ /* turn off DMA for audio channel 2 */
+ custom.dmacon = DMAF_AUD2;
+ /* restore period to previous value after beeping */
+ custom.aud[2].audper = amiga_audio_period;
+}
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