patch-1.3.94 linux/arch/m68k/atari/atasound.c

• Lines: 151
• Date: Thu Apr 18 02:04:17 1996
• Orig file: v1.3.93/linux/arch/m68k/atari/atasound.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.93/linux/arch/m68k/atari/atasound.c linux/arch/m68k/atari/atasound.c
@@ -0,0 +1,150 @@
+/*
+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 README.legal in the main directory of this archive
+for more details.
+
+*/
+
+
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/major.h>
+#include <linux/config.h>
+#include <linux/fcntl.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+
+#include <asm/atarihw.h>
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/pgtable.h>
+#include <asm/atariints.h>
+#include <asm/bootinfo.h>
+
+
+/*
+ * stuff from the old atasound.c
+ */
+
+
+static void atari_nosound (unsigned long ignored)
+{
+	unsigned char	tmp;
+	unsigned long flags;
+	
+	/* turn off generator A in mixer control */
+	save_flags(flags);
+	cli();
+	sound_ym.rd_data_reg_sel = 7;
+	tmp = sound_ym.rd_data_reg_sel;
+	sound_ym.wd_data = tmp | 0x39;
+	restore_flags(flags);
+}	
+		
+
+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)
+		;
+}
+
+
+#define	PC_FREQ		1192180
+#define	PSG_FREQ	125000
+
+
+void atari_mksound (unsigned int count, unsigned int ticks)
+{
+	static struct timer_list sound_timer = { NULL, NULL, 0, 0,
+						     atari_nosound };
+	/*
+	 * Generates sound of some count for some number of clock ticks
+	 * [count = 1193180 / frequency]
+	 */
+	unsigned long flags;
+	unsigned char tmp;
+
+	save_flags(flags);
+	cli();
+
+	if (count == 750 && ticks == HZ/8) {
+		/* Special case: These values are used by console.c to
+		 * generate the console bell. They are catched here and the
+		 * sound actually generated is somehow special: it uses the
+		 * generator B and an envelope. No timer is needed therefore
+		 * and the bell doesn't disturb an other ongoing sound.
+		 */
+
+		/* set envelope duration to 492 ms */
+		sound_ym.rd_data_reg_sel = 11;
+		sound_ym.wd_data = 0;
+		sound_ym.rd_data_reg_sel = 12;
+		sound_ym.wd_data = 15;
+		/* envelope form: max -> min single */
+		sound_ym.rd_data_reg_sel = 13;
+		sound_ym.wd_data = 9;
+		/* set generator B frequency to 2400 Hz */
+		sound_ym.rd_data_reg_sel = 2;
+		sound_ym.wd_data = 52;
+		sound_ym.rd_data_reg_sel = 3;
+		sound_ym.wd_data = 0;
+		/* set volume of generator B to envelope control */
+		sound_ym.rd_data_reg_sel = 9;
+		sound_ym.wd_data = 0x10;
+		/* enable generator B in the mixer control */
+		sound_ym.rd_data_reg_sel = 7;
+		tmp = sound_ym.rd_data_reg_sel;
+		sound_ym.wd_data = (tmp & ~0x02) | 0x38;
+
+		restore_flags(flags);
+		return;
+	}
+
+	del_timer( &sound_timer );
+
+	if (!count) {
+		atari_nosound( 0 );
+	}
+	else {
+
+		/* convert from PC counter value (base frequency 1.193 MHz)
+		 * to PSG period value (base frequency 125 kHz).
+		 */
+		int period = (PSG_FREQ * count + PC_FREQ/2) / PC_FREQ;
+
+		if (period > 0xfff) period = 0xfff;
+
+		/* set generator A frequency to 0 */
+		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;
+		/* turn on generator A in mixer control (but not noise
+		 * generator!) */
+		sound_ym.rd_data_reg_sel = 7;
+		tmp = sound_ym.rd_data_reg_sel;
+		sound_ym.wd_data = (tmp & ~0x01) | 0x38;
+		/* set generator A level to maximum, no envelope */
+		sound_ym.rd_data_reg_sel = 8;
+		sound_ym.wd_data = 15;
+		
+		if (ticks) {
+			sound_timer.expires = jiffies + ticks;
+			add_timer( &sound_timer );
+		}
+	}
+
+	restore_flags(flags);
+}