Patch FS#5712 by Michael Sevakis - X5 Backlight brightness improvement/fix

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10322 a1c6a512-1295-4272-9138-f99709370657

6 files changed, 32 insertions, 19 deletions

diff --git a/apps/settings.c b/apps/settings.c
index db3b45d..b3623f2 100644
--- a/apps/settings.c
+++ b/apps/settings.c
@@ -349,7 +349,7 @@ static const struct bit_entry hd_bits[] =
         "remote caption backlight", off_on },
 #endif
 #ifdef HAVE_BACKLIGHT_BRIGHTNESS
-    {4, S_O(brightness), 9, "brightness", NULL },
+    {4, S_O(brightness), DEFAULT_BRIGHTNESS_SETTING, "brightness", NULL },
 #endif
 #ifdef HAVE_BACKLIGHT_PWM_FADING
     /* backlight fading */
diff --git a/docs/CREDITS b/docs/CREDITS
index fa6ec5d..e71ae8c 100644
--- a/docs/CREDITS
+++ b/docs/CREDITS
@@ -216,3 +216,4 @@ Daniel Ankers
 Paul Louden
 Rainer Sinsch
 Plácido Revilla
+Michael Sevakis
diff --git a/firmware/backlight.c b/firmware/backlight.c
index 8285ff8..1e72c6a 100644
--- a/firmware/backlight.c
+++ b/firmware/backlight.c
@@ -659,28 +659,26 @@ bool is_remote_backlight_on(void) {return true;}
 void backlight_set_brightness(int val)
 {
 #ifndef SIMULATOR
-    /* set H300 brightness by changing the PWM
-       accepts 0..15 but note that 0 and 1 give a black display! */
+    /* set brightness by changing the PWM
+     * accepts 0..15 but note that 0 and 1 give a black display on H300!
+     * 0 is black on the X5.
+     */
 
     /* disable IRQs while bitbanging */
     int old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
 
-    val &= 0x0F;
+    /* Clamp setting to range */
     if(val<MIN_BRIGHTNESS_SETTING)
         val=MIN_BRIGHTNESS_SETTING;
+    else if(val>MAX_BRIGHTNESS_SETTING)
+        val=MAX_BRIGHTNESS_SETTING;
 
-    /* shift one bit left */
-    val <<= 1;
-
-    /* enable PWM */
-    val |= 0x01;
-
-    pcf50606_write(0x35, val);
+    pcf50606_write(0x35, (val << 1) | 0x01); /* 512Hz, Enable PWM */
 
     /* enable IRQs again */
     set_irq_level(old_irq_level);
 #else
-	val=0;
+    val=0;
 #endif
 }
 #endif
diff --git a/firmware/export/backlight.h b/firmware/export/backlight.h
index c1a7ade..09960b7 100644
--- a/firmware/export/backlight.h
+++ b/firmware/export/backlight.h
@@ -53,7 +53,16 @@ void sim_remote_backlight(int value);
 #endif
 
 #ifdef HAVE_BACKLIGHT_BRIGHTNESS
-#define MIN_BRIGHTNESS_SETTING      2
-#define MAX_BRIGHTNESS_SETTING      15
+#ifdef IAUDIO_X5
+/* PFC50506 can output 0%-100% duty cycle but D305A expects %15-100%. */
+#define MIN_BRIGHTNESS_SETTING      1  /* 15/16 (93.75%) */
+#define MAX_BRIGHTNESS_SETTING      13 /*  3/16 (18.75%) */
+#define DEFAULT_BRIGHTNESS_SETTING  8  /*  8/16 (50.00%) = x5 boot default */
+#else
+#define MIN_BRIGHTNESS_SETTING      2  /*  2/16 (12.50%) */
+#define MAX_BRIGHTNESS_SETTING      15 /* 15/16 (93.75%) */
+#define DEFAULT_BRIGHTNESS_SETTING  9  /*  9/16 (56.25%) */
+#endif /* HAVE_BACKLIGHT_BRIGHTNESS */
+
 void backlight_set_brightness(int val);
 #endif
diff --git a/firmware/target/coldfire/iaudio/x5/backlight-x5.c b/firmware/target/coldfire/iaudio/x5/backlight-x5.c
index e48e55d..2b09d14 100755
--- a/firmware/target/coldfire/iaudio/x5/backlight-x5.c
+++ b/firmware/target/coldfire/iaudio/x5/backlight-x5.c
@@ -25,14 +25,13 @@
 void __backlight_on(void)
 {
     int level = set_irq_level(HIGHEST_IRQ_LEVEL);
-    pcf50606_write(0x38, 0x30); /* Backlight ON */
+    pcf50606_write(0x38, 0xb0); /* Backlight ON, GPO1INV=1, GPO1ACT=011 */
     set_irq_level(level);
 }
 
 void __backlight_off(void)
 {
     int level = set_irq_level(HIGHEST_IRQ_LEVEL);
-    pcf50606_write(0x38, 0x70); /* Backlight OFF */
+    pcf50606_write(0x38, 0x80); /* Backlight OFF, GPO1INV=1, GPO1ACT=000 */
     set_irq_level(level);
 }
-
diff --git a/firmware/target/coldfire/iaudio/x5/pcf50606-x5.c b/firmware/target/coldfire/iaudio/x5/pcf50606-x5.c
index da13f1d..158e0fb 100644
--- a/firmware/target/coldfire/iaudio/x5/pcf50606-x5.c
+++ b/firmware/target/coldfire/iaudio/x5/pcf50606-x5.c
@@ -169,6 +169,12 @@ void pcf50606_init(void)
     pcf50606_write(0x39, 0x00); /* GPOOD0 = green led OFF */
     pcf50606_write(0x3a, 0x00); /* GPOOD1 = red led OFF */
 
-    pcf50606_write(0x35, 0xf1); /* Backlight PWM = 7kHz 8/16 */
-    pcf50606_write(0x38, 0x30); /* Backlight ON */
+    /* D305A datasheet says PWM clock frequency should be 400Hz - 2000Hz so
+     * I changed it from 7kHz to 512Hz. The lower frequency looks the same.
+     * GPO1 is also inverted so that display brightness increases with PWM
+     * setting which also lets the X5 share the H300's
+     * set_backlight_brightness code.
+     */
+    pcf50606_write(0x35, 0x11); /* Backlight PWM = 512Hz, 8/16, Active */
+    pcf50606_write(0x38, 0xb0); /* Backlight ON, GPO1INV=1, GPO1ACT=011 */
 }