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-rw-r--r--firmware/asm/m68k/pcm-mixer.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/firmware/asm/m68k/pcm-mixer.c b/firmware/asm/m68k/pcm-mixer.c
new file mode 100644
index 0000000000..d8318fffaf
--- /dev/null
+++ b/firmware/asm/m68k/pcm-mixer.c
@@ -0,0 +1,134 @@
+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id$
+ *
+ * Copyright (C) 2011 by Michael Sevakis
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#define MIXER_OPTIMIZED_MIX_SAMPLES
+#define MIXER_OPTIMIZED_WRITE_SAMPLES
+static struct emac_context
+{
+ unsigned long r[4];
+} emac_context IBSS_ATTR;
+
+/* Save emac context affected in ISR */
+static FORCE_INLINE void save_emac_context(void)
+{
+ asm volatile (
+ "move.l %%macsr, %%d0 \n"
+ "move.l %%accext01, %%d1 \n"
+ "movclr.l %%acc0, %%a0 \n"
+ "movclr.l %%acc1, %%a1 \n"
+ "movem.l %%d0-%%d1/%%a0-%%a1, (%0) \n"
+ :
+ : "a"(&emac_context)
+ : "d0", "d1", "a0", "a1");
+}
+
+/* Restore emac context affected in ISR */
+static FORCE_INLINE void restore_emac_context(void)
+{
+ asm volatile (
+ "movem.l (%0), %%d0-%%d1/%%a0-%%a1 \n"
+ "move.l %%a1, %%acc1 \n"
+ "move.l %%a0, %%acc0 \n"
+ "move.l %%d1, %%accext01 \n"
+ "move.l %%d0, %%macsr \n"
+ :
+ : "a"(&emac_context)
+ : "d0", "d1", "a0", "a1");
+}
+
+/* Mix channels' samples and apply gain factors */
+static FORCE_INLINE void mix_samples(void *out,
+ void *src0,
+ int32_t src0_amp,
+ void *src1,
+ int32_t src1_amp,
+ size_t size)
+{
+ uint32_t s0, s1, s2, s3;
+ save_emac_context();
+ coldfire_set_macsr(EMAC_ROUND | EMAC_SATURATE);
+
+ asm volatile (
+ "move.l (%1)+, %5 \n"
+ "1: \n"
+ "movea.w %5, %4 \n"
+ "asr.l %10, %5 \n"
+ "mac.l %4, %8, %%acc0 \n"
+ "mac.l %5, %8, (%2)+, %5, %%acc1 \n"
+ "movea.w %5, %4 \n"
+ "asr.l %10, %5 \n"
+ "mac.l %4, %9, %%acc0 \n"
+ "mac.l %5, %9, (%1)+, %5, %%acc1 \n"
+ "movclr.l %%acc0, %6 \n"
+ "movclr.l %%acc1, %7 \n"
+ "swap.w %6 \n"
+ "move.w %6, %7 \n"
+ "move.l %7, (%0)+ \n"
+ "subq.l #4, %3 \n"
+ "bhi.b 1b \n"
+ : "+a"(out), "+a"(src0), "+a"(src1), "+d"(size),
+ "=&a"(s0), "=&d"(s1), "=&d"(s2), "=&d"(s3)
+ : "r"(src0_amp), "r"(src1_amp), "d"(16)
+ );
+
+ restore_emac_context();
+}
+
+/* Write channel's samples and apply gain factor */
+static FORCE_INLINE void write_samples(void *out,
+ void *src,
+ int32_t amp,
+ size_t size)
+{
+ if (LIKELY(amp == MIX_AMP_UNITY))
+ {
+ /* Channel is unity amplitude */
+ memcpy(out, src, size);
+ }
+ else
+ {
+ /* Channel needs amplitude cut */
+ uint32_t s0, s1, s2, s3;
+ save_emac_context();
+ coldfire_set_macsr(EMAC_ROUND | EMAC_SATURATE);
+
+ asm volatile (
+ "move.l (%1)+, %4 \n"
+ "1: \n"
+ "movea.w %4, %3 \n"
+ "asr.l %8, %4 \n"
+ "mac.l %3, %7, %%acc0 \n"
+ "mac.l %4, %7, (%1)+, %4, %%acc1 \n"
+ "movclr.l %%acc0, %5 \n"
+ "movclr.l %%acc1, %6 \n"
+ "swap.w %5 \n"
+ "move.w %5, %6 \n"
+ "move.l %6, (%0)+ \n"
+ "subq.l #4, %2 \n"
+ "bhi.b 1b \n"
+ : "+a"(out), "+a"(src), "+d"(size),
+ "=&a"(s0), "=&d"(s1), "=&d"(s2), "=&d"(s3)
+ : "r"(amp), "d"(16)
+ );
+
+ restore_emac_context();
+ }
+}