From 5df7abc86573d8e66e3de781214520ea27ec166e Mon Sep 17 00:00:00 2001
From: jethead71 <jethead71@a1c6a512-1295-4272-9138-f99709370657>
Date: Tue, 11 May 2010 04:02:45 +0000
Subject: [PATCH] MRobe100, HD200, Gigabeat F/X (anything with wm8750 or
 wm8751). Properly prescale bass and treble controls to avoid clipping.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25940 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/drivers/audio/wm8751.c | 14 ++++++++++++++
 firmware/export/wm8751.h        |  8 ++++----
 firmware/sound.c                |  7 +++----
 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/firmware/drivers/audio/wm8751.c b/firmware/drivers/audio/wm8751.c
index 18441826d..e7c0b18da 100644
--- a/firmware/drivers/audio/wm8751.c
+++ b/firmware/drivers/audio/wm8751.c
@@ -61,6 +61,8 @@ const struct sound_settings_info audiohw_settings[] = {
 /* We use linear treble control with 4 kHz cutoff */
 #define TREBCTRL_BITS   (TREBCTRL_TC)
 
+static int prescaler = 0;
+
 /* convert tenth of dB volume (-730..60) to master volume register value */
 int tenthdb2master(int db)
 {
@@ -173,6 +175,10 @@ void audiohw_postinit(void)
                   PWRMGMT2_ROUT2);
 #endif
 
+    /* Full -0dB on the DACS */
+    wmcodec_write(LEFTGAIN, 0xff);
+    wmcodec_write(RIGHTGAIN, RIGHTGAIN_RDVU | 0xff);
+
     wmcodec_write(ADDITIONAL1, ADDITIONAL1_TSDEN | ADDITIONAL1_TOEN |
                     ADDITIONAL1_DMONOMIX_LLRR | ADDITIONAL1_VSEL_DEFAULT);
 
@@ -249,6 +255,14 @@ void audiohw_set_treble(int value)
         TREBCTRL_TREB(tone_tenthdb2hw(value)));
 }
 
+void audiohw_set_prescaler(int value)
+{
+    prescaler = 2 * value;
+    wmcodec_write(LEFTGAIN, 0xff - (prescaler & LEFTGAIN_LDACVOL));
+    wmcodec_write(RIGHTGAIN, RIGHTGAIN_RDVU |
+                  (0xff - (prescaler & RIGHTGAIN_RDACVOL)));
+}
+
 /* Nice shutdown of WM8751 codec */
 void audiohw_close(void)
 {
diff --git a/firmware/export/wm8751.h b/firmware/export/wm8751.h
index fb7532bfd..8992c8807 100644
--- a/firmware/export/wm8751.h
+++ b/firmware/export/wm8751.h
@@ -25,7 +25,7 @@
 #define VOLUME_MIN -730
 #define VOLUME_MAX  60
 
-#define AUDIOHW_CAPS (BASS_CAP | TREBLE_CAP)
+#define AUDIOHW_CAPS (BASS_CAP | TREBLE_CAP | PRESCALER_CAP)
 
 extern int tenthdb2master(int db);
 
@@ -96,12 +96,12 @@ void audiohw_set_recsrc(int source, bool recording);
 #define CLOCKING_BCLK_DIV2          (1 << 7)
 
 #define LEFTGAIN                    0x0a
-#define LEFTGAIN_LDACVOL(x)         ((x) & 0xff)
+#define LEFTGAIN_LDACVOL            0xff
 #define LEFTGAIN_LDVU               (1 << 8)
 
 #define RIGHTGAIN                   0x0b
-#define RIGHTGAIN_LDACVOL(x)        ((x) & 0xff)
-#define RIGHTGAIN_LDVU              (1 << 8)
+#define RIGHTGAIN_RDACVOL           0xff
+#define RIGHTGAIN_RDVU              (1 << 8)
 
 #define BASSCTRL                    0x0c
 #define BASSCTRL_BASS(x)            ((x) & 0xf)
diff --git a/firmware/sound.c b/firmware/sound.c
index 4f95b6ed5..2973721e1 100644
--- a/firmware/sound.c
+++ b/firmware/sound.c
@@ -189,8 +189,7 @@ static void set_prescaled_volume(void)
  */
 #if defined(HAVE_SW_TONE_CONTROLS) || !(defined(HAVE_WM8975) \
     || defined(HAVE_WM8711) || defined(HAVE_WM8721) || defined(HAVE_WM8731) \
-    || defined(HAVE_WM8751) || defined(HAVE_WM8758) || defined(HAVE_WM8985) \
-    || defined(HAVE_UDA1341))
+    || defined(HAVE_WM8758) || defined(HAVE_WM8985) || defined(HAVE_UDA1341))
 
     prescale = MAX(current_bass, current_treble);
     if (prescale < 0)
@@ -297,7 +296,7 @@ void sound_set_bass(int value)
 
 #if !defined(AUDIOHW_HAVE_CLIPPING)
 #if defined(HAVE_WM8750) || defined(HAVE_WM8751)
-    current_bass = value;
+    current_bass = value / 15;
 #else
     current_bass =  value * 10;
 #endif
@@ -321,7 +320,7 @@ void sound_set_treble(int value)
 
 #if !defined(AUDIOHW_HAVE_CLIPPING)
 #if defined(HAVE_WM8750) || defined(HAVE_WM8751)
-    current_treble = value;
+    current_treble = value / 15;
 #else
     current_treble = value * 10;
 #endif
-- 
2.11.4.GIT