Implement PWM backlight driver for the Meizus. Update Meizu M3 bootloader to control brightness with the touch strip.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21478 a1c6a512-1295-4272-9138-f99709370657

8 files changed, 126 insertions, 69 deletions

diff --git a/bootloader/meizu_m3.c b/bootloader/meizu_m3.c
index 2fb0b551a0..84961228b7 100644
--- a/bootloader/meizu_m3.c
+++ b/bootloader/meizu_m3.c
@@ -43,7 +43,7 @@
 #include "rbunicode.h"
 #include "usb.h"
 #include "qt1106.h"
-#include "rockboxlogo.h"
+#include "bitmaps/rockboxlogo.h"
 
 
 #include <stdarg.h>
@@ -108,7 +108,7 @@ void main(void)
     int oldval = PCON0;
     PCON0 = ((oldval & ~(3 << 4)) | (1 << 4));
     PDAT0 |= (1 << 2);
-
+    
     //power on
 //    oldval = PCON1;
 //    PCON1 = ((oldval & ~(0xf << 12)) | (1 << 12));
@@ -128,6 +128,7 @@ void main(void)
     EINTMSK = 0x11;
     asm volatile("msr cpsr_c, #0x13\n\t"); // enable interrupts
         
+    backlight_init();
     lcd_init();
     lcd_update();
 
@@ -157,6 +158,8 @@ void main(void)
         if(slider & 0x008000)
             bl_debug_count(((slider&0xff)) + 1);
         */
+        
+        _backlight_set_brightness(slider & 0xFF);
     }
 
     //power off
diff --git a/firmware/SOURCES b/firmware/SOURCES
index a7741c1870..0eff012660 100644
--- a/firmware/SOURCES
+++ b/firmware/SOURCES
@@ -1241,6 +1241,7 @@ target/arm/s5l8700/meizu-m6sp/lcd-m6sp.c
 #endif /* MEIZU_M6SP */
 
 #ifdef MEIZU_M3
+target/arm/s5l8700/backlight-meizu.c
 target/arm/s5l8700/meizu-m3/lcd-m3.c
 drivers/qt1106.c
 #ifndef SIMULATOR
diff --git a/firmware/export/config-meizu-m3.h b/firmware/export/config-meizu-m3.h
index 2ad20550d0..9e2d6cbf4e 100644
--- a/firmware/export/config-meizu-m3.h
+++ b/firmware/export/config-meizu-m3.h
@@ -178,8 +178,7 @@
 #define DEFAULT_CONTRAST_SETTING    19 /* Match boot contrast */
 
 /* Main LCD backlight brightness range and defaults */
-/* PCF50506 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 */
+#define MIN_BRIGHTNESS_SETTING      0
+#define MAX_BRIGHTNESS_SETTING      255
+#define DEFAULT_BRIGHTNESS_SETTING  200
 
diff --git a/firmware/target/arm/s5l8700/backlight-meizu.c b/firmware/target/arm/s5l8700/backlight-meizu.c
new file mode 100644
index 0000000000..43cbb16a2d
--- /dev/null
+++ b/firmware/target/arm/s5l8700/backlight-meizu.c
@@ -0,0 +1,111 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2009 by Bertrik Sikken
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include <stdbool.h>
+
+#include "config.h"
+#include "backlight.h"
+#include "backlight-target.h"
+#include "system.h"
+
+/*
+    Interrupt-driven backlight driver using the PWM mode of a hardware timer.
+    
+    Backlight brightness is implemented by configuring one of the timers in
+    the SoC for PWM mode. In this mode, two interrupts are generated for each
+    cycle, one at the start of the cycle and another one sometime between the
+    first interrupt and the start of the next cycle. The backlight is switched
+    on at the first interrupt and switched off at the second interrupt. This
+    way, the position in time of the second interrupt determines the duty cycle
+    and thereby the brightness of the backlight.
+    The backlight is switched on and off by means of a GPIO pin.
+ */
+
+void INT_TIMERA(void)
+{
+    unsigned int tacon = TACON;
+    
+    /* clear interrupts */
+    TACON = tacon;
+
+    /* TA_INT1, start of PWM cycle: enable backlight */
+    if (tacon & (1 << 17)) {
+        PDAT0 |= (1 << 2);
+    }
+    
+    /* TA_INT0, disable backlight until next cycle */
+    if (tacon & (1 << 16)) {
+        PDAT0 &= ~(1 << 2);
+    }
+}
+
+void _backlight_set_brightness(int brightness)
+{
+    if (brightness == MIN_BRIGHTNESS_SETTING) {
+        /* turn backlight fully off and disable interrupt */
+        PDAT0 &= ~(1 << 2);
+        INTMSK &= ~(1 << 5);
+    }
+    else if (brightness == MAX_BRIGHTNESS_SETTING) {
+        /* turn backlight fully on and disable interrupt */
+        PDAT0 |= (1 << 2);
+        INTMSK &= ~(1 << 5);
+    }
+    else {
+        /* set PWM width and enable interrupt */
+        TADATA0 = brightness;
+        INTMSK |= (1 << 5);
+    }
+}
+
+void _backlight_on(void)
+{
+    _backlight_set_brightness(backlight_brightness);
+}
+
+void _backlight_off(void)
+{
+    _backlight_set_brightness(MIN_BRIGHTNESS_SETTING);
+}
+
+bool _backlight_init(void)
+{
+    /* enable backlight pin as GPIO */
+    PCON0 = ((PCON0 & ~(3 << 4)) | (1 << 4));
+
+    /* enable timer clock */
+    PWRCON &= ~(1 << 4);
+
+    /* configure timer */
+    TACMD = (1 << 1);   /* TA_CLR */
+    TACMD = (1 << 0);   /* TA_EN */
+    TACON = (1 << 13) | /* TA_INT1_EN */
+            (1 << 12) | /* TA_INT0_EN */
+            (1 << 11) | /* TA_START */
+            (3 << 8) |  /* TA_CS = PCLK / 64 */
+            (1 << 4);   /* TA_MODE_SEL = PWM mode */
+    TADATA1 = MAX_BRIGHTNESS_SETTING;   /* set PWM period */
+    TAPRE = 100;    /* prescaler */
+   
+    _backlight_on();
+
+    return true;
+}
+
diff --git a/firmware/target/arm/s5l8700/meizu-m3/backlight-target.h b/firmware/target/arm/s5l8700/backlight-target.h
index 91579b080d..91579b080d 100644
--- a/firmware/target/arm/s5l8700/meizu-m3/backlight-target.h
+++ b/firmware/target/arm/s5l8700/backlight-target.h
diff --git a/firmware/target/arm/s5l8700/meizu-m6sl/backlight-target.h b/firmware/target/arm/s5l8700/meizu-m6sl/backlight-target.h
deleted file mode 100644
index 91579b080d..0000000000
--- a/firmware/target/arm/s5l8700/meizu-m6sl/backlight-target.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id$
- *
- * Copyright (C) 2008 by Marcoen Hirschberg
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
- * KIND, either express or implied.
- *
- ****************************************************************************/
-#ifndef BACKLIGHT_TARGET_H
-#define BACKLIGHT_TARGET_H
-
-bool _backlight_init(void);
-void _backlight_on(void);
-void _backlight_off(void);
-void _backlight_set_brightness(int brightness);
-
-#endif
diff --git a/firmware/target/arm/s5l8700/meizu-m6sp/backlight-target.h b/firmware/target/arm/s5l8700/meizu-m6sp/backlight-target.h
deleted file mode 100644
index 91579b080d..0000000000
--- a/firmware/target/arm/s5l8700/meizu-m6sp/backlight-target.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id$
- *
- * Copyright (C) 2008 by Marcoen Hirschberg
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
- * KIND, either express or implied.
- *
- ****************************************************************************/
-#ifndef BACKLIGHT_TARGET_H
-#define BACKLIGHT_TARGET_H
-
-bool _backlight_init(void);
-void _backlight_on(void);
-void _backlight_off(void);
-void _backlight_set_brightness(int brightness);
-
-#endif
diff --git a/firmware/target/arm/s5l8700/system-s5l8700.c b/firmware/target/arm/s5l8700/system-s5l8700.c
index c535a0d955..48c50645e9 100644
--- a/firmware/target/arm/s5l8700/system-s5l8700.c
+++ b/firmware/target/arm/s5l8700/system-s5l8700.c
@@ -95,12 +95,13 @@ void irq_handler(void)
     asm volatile(   "stmfd sp!, {r0-r7, ip, lr} \n"   /* Store context */
                     "sub   sp, sp, #8           \n"); /* Reserve stack */
 
-    int irq_no = INTOFFSET;   /* Read clears the corresponding IRQ status */
+    int irq_no = INTOFFSET;
     
-    if ((irq_no & (1<<31)) == 0)  /* Ensure invalid flag is not set */
-    {
-        irqvector[irq_no]();
-    }
+    irqvector[irq_no]();
+
+    /* clear interrupt */
+    SRCPND = (1 << irq_no);
+    INTPND = INTPND;
     
     asm volatile(   "add   sp, sp, #8           \n"   /* Cleanup stack   */
                     "ldmfd sp!, {r0-r7, ip, lr} \n"   /* Restore context */