From d52bea8a90a4888efae8a8716d0025d3f4238733 Mon Sep 17 00:00:00 2001
From: Jens Arnold <amiconn@rockbox.org>
Date: Thu, 29 May 2008 21:41:47 +0000
Subject: [PATCH] Fix FS #8840 for irivers by slowing down the driver some
 more. Signal quality is obviously varying a lot among the iriver remotes.
 Speed is now around halfway between pre-r16832 and r17006 when boosted.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17657 a1c6a512-1295-4272-9138-f99709370657
---
 .../coldfire/iriver/lcd-remote-as-iriver.S    | 42 +++++++++++++------
 .../coldfire/iriver/lcd-remote-iriver.c       |  4 +-
 2 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/firmware/target/coldfire/iriver/lcd-remote-as-iriver.S b/firmware/target/coldfire/iriver/lcd-remote-as-iriver.S
index 0325e5176c..df7447a03a 100644
--- a/firmware/target/coldfire/iriver/lcd-remote-as-iriver.S
+++ b/firmware/target/coldfire/iriver/lcd-remote-as-iriver.S
@@ -81,31 +81,47 @@
     eor.l   %d6, %d0            /* invert data bit */
     move.l  %d0, (%a1)          /*   output data bit7 */
     nop
+    nop
 1:
 
 .macro bit_out
+    move.l  %d2, (%a0)          /* Bit7: set CLK = 1 */
+    nop
     lsl.l   #1, %d4             /* Invert data line for bit6 ? */
     bcc.s   1f                  /*   no: skip */
     eor.l   %d6, %d0            /* Invert data bit */
-    move.l  %d2, (%a0)          /* Bit7: set CLK = 1 */
     move.l  %d1, (%a0)          /*       set CLK = 0 */
     move.l  %d0, (%a1)          /* Output data bit6 */
-    bra.s   2f                  /* slower than trapf.l - required here */
-1:                              /*   else */
-    move.l  %d2, (%a0)          /* Bit7: set CLK = 1 */
+    .word   0x51fa              /* trapf.w - shadow next insn */
+1:
     move.l  %d1, (%a0)          /*       set CLK = 0 */
-2:
 .endm
-    bit_out
-    bit_out
-    bit_out
-    bit_out
-    bit_out
-    bit_out
-    bit_out
 
-    nop                         /* Let data line settle */
+    bit_out
+    nop
+    nop
+    bit_out
+    nop
+    nop
+    bit_out
+    nop
+    nop
+    bit_out
+    nop
+    nop
+    bit_out
+    nop
+    nop
+    bit_out
+    nop
+    nop
+    bit_out
+    nop
+    nop
+
     move.l  %d2, (%a0)          /* Bit0: Set CLK = 1 */
+    nop
+    nop
     move.l  %d1, (%a0)          /*       Set CLK = 0 */
 
     move.w  %d3, %sr            /* Restore interrupt level */
diff --git a/firmware/target/coldfire/iriver/lcd-remote-iriver.c b/firmware/target/coldfire/iriver/lcd-remote-iriver.c
index 83b7a022e5..e291771e90 100644
--- a/firmware/target/coldfire/iriver/lcd-remote-iriver.c
+++ b/firmware/target/coldfire/iriver/lcd-remote-iriver.c
@@ -299,7 +299,7 @@ void lcd_remote_update(void)
 
 #ifdef HAVE_REMOTE_LCD_TICKING
     /* Adjust byte delay for emi reduction. */
-    remote_byte_delay = emireduce ? cpu_frequency / 192800 - 100: 0;
+    remote_byte_delay = emireduce ? cpu_frequency / 206200 - 85: 0;
 #endif
 
     /* Copy display bitmap to hardware */
@@ -333,7 +333,7 @@ void lcd_remote_update_rect(int x, int y, int width, int height)
 
 #ifdef HAVE_REMOTE_LCD_TICKING
     /* Adjust byte delay for emi reduction */
-    remote_byte_delay = emireduce ? cpu_frequency / 192800 - 100: 0;
+    remote_byte_delay = emireduce ? cpu_frequency / 206200 - 85: 0;
 #endif
 
     /* Copy specified rectange bitmap to hardware */