From 05fdb1ad30bbeeabe3cb74f4f5d366a53c8f3cef Mon Sep 17 00:00:00 2001
From: Miika Pekkarinen <miipekk@ihme.org>
Date: Sat, 19 Nov 2005 07:58:20 +0000
Subject: [PATCH] Added option to reduce (and almost prevent) the remote lcd
 ticking problem with a cost slightly more CPU usage.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7985 a1c6a512-1295-4272-9138-f99709370657
---
 apps/lang/english.lang             |  7 +++++++
 apps/settings.c                    |  4 ++++
 apps/settings.h                    |  2 ++
 apps/settings_menu.c               | 13 ++++++++++++-
 firmware/drivers/lcd-h100-remote.c | 18 +++++++++++++++---
 firmware/export/lcd-remote.h       |  1 +
 6 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/apps/lang/english.lang b/apps/lang/english.lang
index 58ec145a29..5e49b95708 100644
--- a/apps/lang/english.lang
+++ b/apps/lang/english.lang
@@ -3454,3 +3454,10 @@ desc: Custom themes menu
 eng: "Browse Themes"
 voice: "Browse Themes"
 new:
+
+id: LANG_REDUCE_TICKING
+desc: in remote lcd settings menu
+eng: "Reduce ticking"
+voice: "Reduce ticking"
+new:
+
diff --git a/apps/settings.c b/apps/settings.c
index 36bd332ae3..02fa6ee69f 100644
--- a/apps/settings.c
+++ b/apps/settings.c
@@ -277,6 +277,10 @@ static const struct bit_entry rtc_bits[] =
     {1, S_O(bidi_support), false, "bidi hebrew/arabic", off_on },
 #endif
 
+#ifdef HAVE_REMOTE_LCD /* move to REMOTE_LCD next time we bump version */
+    {1, S_O(remote_reduce_ticking), false, "remote reduce ticking", off_on },
+#endif
+
     /* new stuff to be added here */
     /* If values are just added to the end, no need to bump the version. */
 
diff --git a/apps/settings.h b/apps/settings.h
index c41ee1d8e3..0dd9789991 100644
--- a/apps/settings.h
+++ b/apps/settings.h
@@ -343,6 +343,8 @@ struct user_settings
     int remote_backlight_timeout;  /* backlight off timeout:  0-18 0=never,
                                1=always,
                                then according to timeout_values[] */
+    bool remote_reduce_ticking; /* 0=normal operation,
+                                   1=EMI reduce on with cost more CPU. */
 #endif
     
     bool next_folder; /* move to next folder */
diff --git a/apps/settings_menu.c b/apps/settings_menu.c
index 27e24347a3..05fcacf77a 100644
--- a/apps/settings_menu.c
+++ b/apps/settings_menu.c
@@ -120,6 +120,16 @@ static bool remote_flip_display(void)
 
     return rc;
 }
+
+static bool remote_reduce_ticking(void)
+{
+    bool rc = set_bool( str(LANG_REDUCE_TICKING),
+                        &global_settings.remote_reduce_ticking);
+    
+    lcd_remote_emireduce(global_settings.remote_reduce_ticking);
+
+    return rc;
+}
 #endif
 
 #ifdef CONFIG_BACKLIGHT
@@ -1540,7 +1550,8 @@ static bool lcd_remote_settings_menu(void)
         { ID2P(LANG_CONTRAST),        remote_contrast },
         { ID2P(LANG_INVERT),          remote_invert },
         { ID2P(LANG_FLIP_DISPLAY),    remote_flip_display },
-    };
+        { ID2P(LANG_REDUCE_TICKING),  remote_reduce_ticking },
+};
 
     m=menu_init( items, sizeof(items) / sizeof(*items), NULL,
                  NULL, NULL, NULL);
diff --git a/firmware/drivers/lcd-h100-remote.c b/firmware/drivers/lcd-h100-remote.c
index aaf8a1efd6..221338b2d9 100644
--- a/firmware/drivers/lcd-h100-remote.c
+++ b/firmware/drivers/lcd-h100-remote.c
@@ -61,7 +61,11 @@
 #define RS_HI      or_l(0x00010000, &GPIO_OUT)
 
 /* delay loop */
-#define DELAY   do { int _x; for(_x=0;_x<3;_x++);} while (0)
+#define DELAY_DEFAULT   do { int _x = 0; for (_x = 0;_x < 2;_x++); } while (0)
+#define DELAY_EMIREDUCE do { int _x = cpu_frequency >> 21; while (_x--); } \
+                            while (0)
+#define DELAY   do { if (emireduce) DELAY_EMIREDUCE; \
+                    else DELAY_DEFAULT; } while (0)
 
 #define SCROLLABLE_LINES 13
 
@@ -77,6 +81,9 @@ static int curfont = FONT_SYSFIXED;
 #ifndef SIMULATOR
 static int xoffset; /* needed for flip */
 
+/* If set to true, will prevent "ticking" to headphones. */
+static bool emireduce = false;
+
 /* remote hotplug */
 static int countdown;  /* for remote plugging debounce */
 static bool last_remote_status = false;
@@ -177,7 +184,7 @@ void lcd_remote_write_data(const unsigned char* p_bytes, int count)
                 CLK_HI;
                 data <<= 1;
                 DELAY;
-            
+                
                 CLK_LO;
             }
         }
@@ -343,6 +350,11 @@ int lcd_remote_default_contrast(void)
 
 #ifndef SIMULATOR
 
+void lcd_remote_emireduce(bool state)
+{
+    emireduce = state;
+}
+
 void lcd_remote_powersave(bool on)
 {
     if (remote_initialized)
@@ -476,7 +488,7 @@ static void remote_tick(void)
             }
         }
     }
-}  
+}
 #endif /* !SIMULATOR */
 
 /* LCD init */
diff --git a/firmware/export/lcd-remote.h b/firmware/export/lcd-remote.h
index bc7f84ca83..6d5091fc66 100644
--- a/firmware/export/lcd-remote.h
+++ b/firmware/export/lcd-remote.h
@@ -34,6 +34,7 @@ extern void lcd_remote_backlight_on(void);
 extern void lcd_remote_backlight_off(void);
 extern int  lcd_remote_default_contrast(void);
 extern void lcd_remote_set_contrast(int val);
+extern void lcd_remote_emireduce(bool state);
 
 extern void lcd_remote_clear_display(void);
 extern void lcd_remote_puts(int x, int y, const unsigned char *string);