Sansa AMS PCM : replace buggy and confusing one-liner

The bits which are not divider (i2si/i2so enable and clock selection)
would be unset.
This is not a problem in the current code since this function was always
called before starting playback (and setting those bits) but this might
be a problem when recording is enabled.

Finally it is simpler to read.

Thanks to Fred Bauer for pointing this.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@23156 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 8 insertions, 3 deletions

diff --git a/firmware/target/arm/as3525/pcm-as3525.c b/firmware/target/arm/as3525/pcm-as3525.c
index 4f9e18523d..20579806c0 100644
--- a/firmware/target/arm/as3525/pcm-as3525.c
+++ b/firmware/target/arm/as3525/pcm-as3525.c
@@ -150,9 +150,14 @@ void pcm_dma_apply_settings(void)
     if(divider < 0 || divider > 511)
         panicf("unsupported frequency %ld", frequency);
 
-    CGU_AUDIO &= ~(((511 ^ divider) << 2) /* I2SOUT */
-            /*| ((511 ^ divider) << 14) */ /* I2SIN */
-            );
+    int cgu_audio = CGU_AUDIO;  /* read register */
+    cgu_audio &= ~(511 << 2);   /* clear i2sout divider */
+    cgu_audio |= divider << 2;  /* set new i2sout divider */
+#if 0
+    cgu_audio &= ~(511 << 14);  /* clear i2sin divider */
+    cgu_audio |= divider << 14; /* set new i2sin divider */
+#endif
+    CGU_AUDIO = cgu_audio;      /* write back register */
 }
 
 size_t pcm_get_bytes_waiting(void)