1 files changed, 144 insertions, 0 deletions

diff --git a/lib/rbcodec/dsp/pga.c b/lib/rbcodec/dsp/pga.c
new file mode 100644
index 0000000000..c2c29ccfc0
--- /dev/null
+++ b/lib/rbcodec/dsp/pga.c
@@ -0,0 +1,144 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2005 Magnus Holmgren
+ * Copyright (C) 2012 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.
+ *
+ ****************************************************************************/
+#include "config.h"
+#include "system.h"
+#include "dsp.h"
+#include "dsp-util.h"
+#include "fixedpoint.h"
+#include "fracmul.h"
+#include "dsp_proc_entry.h"
+
+/* Implemented here or in target assembly code */
+void pga_process(struct dsp_proc_entry *this, struct dsp_buffer **buf_p);
+
+#define DEFAULT_PGA_GAIN (PGA_UNITY >> 1) /* s8.23 format */
+
+static struct pga_data
+{
+    int32_t gain;                 /* 00h: Final gain in s8.23 format */
+    uint32_t enabled;             /* Mask of enabled gains */
+    int32_t gains[PGA_NUM_GAINS]; /* Individual gains in s7.24 format */
+} pga_data =
+{
+    .gain = DEFAULT_PGA_GAIN,
+    .enabled = 0,
+    .gains[0 ... PGA_NUM_GAINS-1] = PGA_UNITY,
+};
+
+/* Combine all gains to a global gain and enable/disable the amplifier if
+   the overall gain is not unity/unity */
+static void pga_update(void)
+{
+    int32_t gain = PGA_UNITY;
+
+    /* Multiply all gains with one another to get overall amp gain */
+    for (int i = 0; i < PGA_NUM_GAINS; i++)
+    {
+        if (pga_data.enabled & BIT_N(i)) /* Only enabled gains factor in */
+            gain = fp_mul(gain, pga_data.gains[i], 24);
+    }
+
+    gain >>= 1; /* s7.24 -> s8.23 format */
+
+    if (gain == pga_data.gain)
+        return;
+
+    struct dsp_config *dsp = dsp_get_config(CODEC_IDX_AUDIO);
+    pga_data.gain = gain;
+    dsp_proc_enable(dsp, DSP_PROC_PGA, gain != DEFAULT_PGA_GAIN);
+    dsp_proc_activate(dsp, DSP_PROC_PGA, true);
+}
+
+
+/** Amp controls **/
+
+/* Set a particular gain value - doesn't have to be enabled */
+void pga_set_gain(enum pga_gain_ids id, int32_t value)
+{
+    if (value == pga_data.gains[id])
+        return;
+
+    pga_data.gains[id] = value;
+
+    if (BIT_N(id) & pga_data.enabled)
+        pga_update();
+}
+
+/* Enable or disable the specified gain stage */
+void pga_enable_gain(enum pga_gain_ids id, bool enable)
+{
+    uint32_t bit = BIT_N(id);
+
+    if (enable != !(pga_data.enabled & bit))
+        return;
+
+    pga_data.enabled ^= bit;
+    pga_update();
+}
+
+
+/** DSP interface **/
+
+#if !defined(CPU_COLDFIRE) && !defined(CPU_ARM)
+/* Apply a constant gain to the samples (e.g., for ReplayGain). */
+void pga_process(struct dsp_proc_entry *this, struct dsp_buffer **buf_p)
+{
+    int32_t gain = ((struct pga_data *)this->data)->gain;
+    struct dsp_buffer *buf = *buf_p;
+    unsigned int channels = buf->format.num_channels;
+
+    for (unsigned int ch = 0; ch < channels; ch++)
+    {
+        int32_t *d = buf->p32[ch];
+        int count = buf->remcount;
+
+        for (int i = 0; i < count; i++)
+            d[i] = FRACMUL_SHL(d[i], gain, 8);
+    }
+
+    (void)this;
+}
+#endif /* CPU */
+
+/* DSP message hook */
+static intptr_t pga_configure(struct dsp_proc_entry *this,
+                              struct dsp_config *dsp,
+                              unsigned int setting,
+                              intptr_t value)
+{
+    switch (setting)
+    {
+    case DSP_PROC_INIT:
+        if (value != 0)
+            break; /* Already initialized */
+        this->data = (intptr_t)&pga_data;
+        this->process[0] = pga_process;
+        break;
+    }
+
+    return 1;
+    (void)dsp;
+}
+
+/* Database entry */
+DSP_PROC_DB_ENTRY(PGA,
+                  pga_configure);