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-rw-r--r--arch/m68k/atari/atasound.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/arch/m68k/atari/atasound.c b/arch/m68k/atari/atasound.c
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+++ b/arch/m68k/atari/atasound.c
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+/*
+ * linux/arch/m68k/atari/atasound.c
+ *
+ * ++Geert: Moved almost all stuff to linux/drivers/sound/
+ *
+ * The author of atari_nosound, atari_mksound and atari_microwire_cmd is
+ * unknown. (++roman: That's me... :-)
+ *
+ * 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.
+ *
+ * 1998-05-31 ++andreas: atari_mksound rewritten to always use the envelope,
+ * no timer, atari_nosound removed.
+ *
+ */
+
+
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/major.h>
+#include <linux/fcntl.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+
+#include <asm/atarihw.h>
+#include <asm/irq.h>
+#include <asm/atariints.h>
+
+
+/*
+ * stuff from the old atasound.c
+ */
+
+void atari_microwire_cmd (int cmd)
+{
+ tt_microwire.mask = 0x7ff;
+ tt_microwire.data = MW_LM1992_ADDR | cmd;
+
+ /* Busy wait for data being completely sent :-( */
+ while( tt_microwire.mask != 0x7ff)
+ ;
+}
+EXPORT_SYMBOL(atari_microwire_cmd);
+
+
+/* PSG base frequency */
+#define PSG_FREQ 125000
+/* PSG envelope base frequency times 10 */
+#define PSG_ENV_FREQ_10 78125
+
+void atari_mksound (unsigned int hz, unsigned int ticks)
+{
+ /* Generates sound of some frequency for some number of clock
+ ticks. */
+ unsigned long flags;
+ unsigned char tmp;
+ int period;
+
+ local_irq_save(flags);
+
+
+ /* Disable generator A in mixer control. */
+ sound_ym.rd_data_reg_sel = 7;
+ tmp = sound_ym.rd_data_reg_sel;
+ tmp |= 011;
+ sound_ym.wd_data = tmp;
+
+ if (hz) {
+ /* Convert from frequency value to PSG period value (base
+ frequency 125 kHz). */
+
+ period = PSG_FREQ / hz;
+
+ if (period > 0xfff) period = 0xfff;
+
+ /* Set generator A frequency to hz. */
+ sound_ym.rd_data_reg_sel = 0;
+ sound_ym.wd_data = period & 0xff;
+ sound_ym.rd_data_reg_sel = 1;
+ sound_ym.wd_data = (period >> 8) & 0xf;
+ if (ticks) {
+ /* Set length of envelope (max 8 sec). */
+ int length = (ticks * PSG_ENV_FREQ_10) / HZ / 10;
+
+ if (length > 0xffff) length = 0xffff;
+ sound_ym.rd_data_reg_sel = 11;
+ sound_ym.wd_data = length & 0xff;
+ sound_ym.rd_data_reg_sel = 12;
+ sound_ym.wd_data = length >> 8;
+ /* Envelope form: max -> min single. */
+ sound_ym.rd_data_reg_sel = 13;
+ sound_ym.wd_data = 0;
+ /* Use envelope for generator A. */
+ sound_ym.rd_data_reg_sel = 8;
+ sound_ym.wd_data = 0x10;
+ } else {
+ /* Set generator A level to maximum, no envelope. */
+ sound_ym.rd_data_reg_sel = 8;
+ sound_ym.wd_data = 15;
+ }
+ /* Turn on generator A in mixer control. */
+ sound_ym.rd_data_reg_sel = 7;
+ tmp &= ~1;
+ sound_ym.wd_data = tmp;
+ }
+ local_irq_restore(flags);
+}