Sansa AMS: implement set_cpu_frequency()

Use a 24MHz peripheral clock instead of 64MHz for battery life

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19234 a1c6a512-1295-4272-9138-f99709370657

firmware/target/arm/as3525/sansa-e200v2/system-target.h

@@ -1,30 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id$
- *
- * Copyright (C) 2008 ??
- *
- * 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 SYSTEM_TARGET_H
-#define SYSTEM_TARGET_H
-
-#include "system-arm.h"
-
-#define CPUFREQ_MAX    250000000
-#define CPUFREQ_DEFAULT 250000000
-#define CPUFREQ_NORMAL 250000000
-
-#endif /* SYSTEM_TARGET_H */

firmware/target/arm/as3525/sansa-fuze/system-target.h

@@ -1,30 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id$
- *
- * Copyright (C) 2008 ??
- *
- * 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 SYSTEM_TARGET_H
-#define SYSTEM_TARGET_H
-
-#include "system-arm.h"
-
-#define CPUFREQ_MAX    250000000
-#define CPUFREQ_DEFAULT 250000000
-#define CPUFREQ_NORMAL  250000000
-
-#endif /* SYSTEM_TARGET_H */

firmware/target/arm/as3525/sansa-m200v4/system-target.h

@@ -1,30 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id$
- *
- * Copyright (C) 2008 ??
- *
- * 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 SYSTEM_TARGET_H
-#define SYSTEM_TARGET_H
-
-#include "system-arm.h"
-
-#define CPUFREQ_MAX     250000000
-#define CPUFREQ_DEFAULT 250000000
-#define CPUFREQ_NORMAL  250000000
-
-#endif /* SYSTEM_TARGET_H */

firmware/target/arm/as3525/system-as3525.c

@@ -219,6 +219,11 @@ void system_init(void)
     while(!(CGU_INTCTRL & (1<<0))); /* wait until PLLA is locked */
 
     CGU_PROC = (3<<2)|0x01; /* fclk = PLLA*5/8 = 240 MHz */
+#ifndef BOOTLOADER
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    set_cpu_frequency(CPUFREQ_DEFAULT);
+#endif
+#endif
 
     asm volatile(
         "mov r0, #0               \n"
@@ -231,8 +236,6 @@ void system_init(void)
 
     sdram_init();
 
-    CGU_PERI |= (5<<2)|0x01; /* pclk = PLLA / 6 = 64 MHz */
-
     /* enable timer interface for TIMER1 & TIMER2 */
     CGU_PERI |= CGU_TIMERIF_CLOCK_ENABLE;
 
@@ -264,11 +267,19 @@ int system_memory_guard(int newmode)
 }
 
 #ifndef BOOTLOADER
-
 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
 void set_cpu_frequency(long frequency)
 {
-    /* TODO */
+    int divider = CPUFREQ_MAX / frequency;
+
+    if(divider > 16)
+        divider = 16;
+    else if(divider < 1)
+        divider = 1;
+
+    cpu_frequency = CPUFREQ_MAX / divider;
+
+    CGU_PROC &= ~(0xf << 4) /* clear divider bits */ ^ ((divider-1) << 4);
 }
 #endif /* HAVE_ADJUSTABLE_CPU_FREQ */
 #endif /* BOOTLOADER */

firmware/target/arm/as3525/system-target.h

@@ -7,7 +7,7 @@
  *                     \/            \/     \/    \/            \/
  * $Id$
  *
- * Copyright (C) 2008 ??
+ * Copyright (C) 2008 Rafaël Carré
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -23,8 +23,8 @@
 
 #include "system-arm.h"
 
-#define CPUFREQ_MAX     250000000
+#define CPUFREQ_MAX     240000000
-#define CPUFREQ_DEFAULT 250000000
+#define CPUFREQ_DEFAULT 24000000
-#define CPUFREQ_NORMAL  250000000
+#define CPUFREQ_NORMAL  30000000
 
 #endif /* SYSTEM_TARGET_H */