From 3c17f28eca86ff3ee9e7cef6c4d5198c27b7c03c Mon Sep 17 00:00:00 2001
From: Thomas Martitz <kugel@rockbox.org>
Date: Fri, 6 Jan 2012 06:26:48 +0100
Subject: Move pcm_mixer helper routines to firmware/asm.

---
 firmware/asm/m68k/pcm-mixer.c | 134 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 firmware/asm/m68k/pcm-mixer.c

(limited to 'firmware/asm/m68k/pcm-mixer.c')

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();
+    }     
+}
-- 
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