FS#10344 - AMSSansa Dynamically adjust core voltage to extend playtime.

Lower CVDD core voltage to 1.10 volts when the frequency is less than 200 MHz.

 

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21577 a1c6a512-1295-4272-9138-f99709370657

3 files changed, 30 insertions, 7 deletions

diff --git a/firmware/target/arm/as3525/ascodec-target.h b/firmware/target/arm/as3525/ascodec-target.h
index c31a1bab0c..3464bbaa51 100644
--- a/firmware/target/arm/as3525/ascodec-target.h
+++ b/firmware/target/arm/as3525/ascodec-target.h
@@ -27,6 +27,20 @@
 
 #include "as3514.h"
 
+/*  Charge Pump and Power management Settings  */
+#define AS314_CP_DCDC3_SETTING    \
+               ((0<<7) |  /* CP_SW  Auto-Switch Margin 0=200/300 1=150/255 */  \
+                (0<<6) |  /* CP_on  0=Normal op 1=Chg Pump Always On  */       \
+                (0<<5) |  /* LREG_CPnot  Always write 0 */                     \
+                (0<<3) |  /* DCDC3p  BVDD setting 3.6/3.2/3.1/3.0  */          \
+                (1<<2) |  /* LREG_off 1=Auto mode switching 0=Length Reg only*/\
+                (0<<0) )  /* CVDDp  Core Voltage Setting 1.2/1.15/1.10/1.05*/
+
+#define CVDD_1_20          0
+#define CVDD_1_15          1
+#define CVDD_1_10          2
+#define CVDD_1_05          3
+
 void ascodec_init(void);
 
 int ascodec_write(unsigned int index, unsigned int value);
diff --git a/firmware/target/arm/as3525/debug-as3525.c b/firmware/target/arm/as3525/debug-as3525.c
index 39f590302d..aade54ca38 100644
--- a/firmware/target/arm/as3525/debug-as3525.c
+++ b/firmware/target/arm/as3525/debug-as3525.c
@@ -28,6 +28,7 @@
 #include "sprintf.h"
 #include "cpu.h"
 #include "pl180.h"
+#include "ascodec-target.h"
 
 #define _DEBUG_PRINTF(a,varargs...) do { \
         snprintf(buf, sizeof(buf), (a), ##varargs); lcd_puts(0,line++,buf); \
@@ -280,7 +281,10 @@ bool __dbg_hw_info(void)
         _DEBUG_PRINTF("SD  :%3dkHz    %3dkHz", AS3525_SD_IDENT_FREQ/1000,calc_freq(CLK_SD_IDENT_NAND)/1000);
         _DEBUG_PRINTF("MSD :%3dkHz    %3dkHz", AS3525_SD_IDENT_FREQ/1000,calc_freq(CLK_SD_IDENT_MSD)/1000);
         _DEBUG_PRINTF("USB:           %3dMHz", calc_freq(CLK_USB)/1000000);
-        _DEBUG_PRINTF("MMU:   %s", (read_cp15() & CP15_MMU) ? " op" : "nop");
+        ascodec_write(AS3514_ADC_0, 4<<4);            /* ADC Source = CVDD */
+        _DEBUG_PRINTF("MMU:   %s CVDDP:%4d", (read_cp15() & CP15_MMU) ? " op" : "nop",
+                                             ((ascodec_read(AS3514_ADC_1) |
+                                             ((ascodec_read(AS3514_ADC_0) & 3)<<8)) * 25));
         _DEBUG_PRINTF("Icache:%s Dcache:%s",(read_cp15() & CP15_IC)  ? " op" : "nop",
                                             (read_cp15() & CP15_DC)  ? " op" : "nop");
 
diff --git a/firmware/target/arm/as3525/system-as3525.c b/firmware/target/arm/as3525/system-as3525.c
index ecb9736f78..b77f3dee9b 100644
--- a/firmware/target/arm/as3525/system-as3525.c
+++ b/firmware/target/arm/as3525/system-as3525.c
@@ -271,7 +271,6 @@ void system_init(void)
                   AS3525_PCLK_SEL);
 
     asm volatile(
-        "mov r0, #0               \n"
         "mrc p15, 0, r0, c1, c0   \n"      /* control register */
         "bic r0, r0, #3<<30       \n"      /* clears bus bits : sets fastbus */
         "mcr p15, 0, r0, c1, c0   \n"
@@ -295,10 +294,8 @@ void system_init(void)
     ascodec_init();
 
 #ifndef BOOTLOADER
-    /* Disable fast hardware power-off, to use power button normally
-     * We don't need the power button in the bootloader. */
-    ascodec_write(AS3514_CVDD_DCDC3, ascodec_read(AS3514_CVDD_DCDC3) & (1<<2));
-
+    /*  Initialize power management settings */
+    ascodec_write(AS3514_CVDD_DCDC3, AS314_CP_DCDC3_SETTING);
 #ifdef CONFIG_TUNER
     fmradio_i2c_init();
 #endif
@@ -331,7 +328,12 @@ void set_cpu_frequency(long frequency)
 {
     if(frequency == CPUFREQ_MAX)
     {
-
+        /* Increasing frequency so boost voltage before change */
+        ascodec_write(AS3514_CVDD_DCDC3, (AS314_CP_DCDC3_SETTING | CVDD_1_20));
+        /* Confirm voltage is at least 1.20v before making fclk > 200 MHz */
+        ascodec_write(AS3514_ADC_0, 4<<4);            /* ADC Source = CVDD */
+        while (ascodec_read(AS3514_ADC_1) < 0xe0);    /* 0x1e0 *.0025 = 1.20  */
+                                                      /* e0 = 8LSB's of 0x1e0 */
         asm volatile(
             "mrc p15, 0, r0, c1, c0  \n"
 
@@ -355,6 +357,9 @@ void set_cpu_frequency(long frequency)
             "mcr p15, 0, r0, c1, c0  \n"
             : : : "r0" );
 
+        /* Decreasing frequency so reduce voltage after change */
+        ascodec_write(AS3514_CVDD_DCDC3, (AS314_CP_DCDC3_SETTING | CVDD_1_10));
+
         cpu_frequency = CPUFREQ_NORMAL;
     }
 }