Enable frequency scaling on AMSv2 devices.

Voltage scaling is not yet enabled, but will follow once we are sure
these changes are stable.  Preliminary testing suggests a large
increase in battery life, which will be further improved by voltage
scaling.  Patch by Mihail Zenkov with help from myself and others on
the forums.

Change-Id: I171d20bbee19a48c13cd14efb0d023883cc8c687

2 files changed, 23 insertions, 46 deletions

diff --git a/firmware/target/arm/as3525/clock-target.h b/firmware/target/arm/as3525/clock-target.h
index 97d6edb3d1..f4bb5568fb 100644
--- a/firmware/target/arm/as3525/clock-target.h
+++ b/firmware/target/arm/as3525/clock-target.h
@@ -70,11 +70,8 @@
  * - bit 12  = unknown (always set to 1)
  * Fpll = Fin * F / (R * OD), where Fin = 12 MHz
  */
-#define AS3525_PLLA_FREQ        240000000
-#define AS3525_PLLA_SETTING     0x113B
-
-#define AS3525_PLLB_FREQ        192000000   /* allows 44.1kHz with 0.04% error*/
-#define AS3525_PLLB_SETTING     0x155F
+#define AS3525_PLLA_FREQ        192000000   /* allows 44.1kHz with 0.04% error*/
+#define AS3525_PLLA_SETTING     0x155F
 
 #define AS3525_FCLK_PREDIV      0
 #define AS3525_FCLK_FREQ        AS3525_PLLA_FREQ
@@ -86,13 +83,9 @@
  * Also note that CGU_PERI is based on fclk, not PLLA
  */
 
-#ifdef SANSA_FUZEV2
-/* display is unbearably slow at 24MHz
- * 34285715 HZ works ok but 40MHz works even better*/
-#define AS3525_DRAM_FREQ        40000000    /* Initial DRAM frequency  */
-#else
-#define AS3525_DRAM_FREQ        24000000    /* Initial DRAM frequency  */
-#endif /* SANSA_FUZEV2 */
+
+
+#define AS3525_DRAM_FREQ        96000000    /* Initial DRAM frequency  */
 
 #else
 /* AS3525v1 */
@@ -131,8 +124,8 @@
 
 /* Tell the software what frequencies we're running */
 #define CPUFREQ_MAX              AS3525_FCLK_FREQ
-#define CPUFREQ_DEFAULT          AS3525_PCLK_FREQ
-#define CPUFREQ_NORMAL           AS3525_PCLK_FREQ
+#define CPUFREQ_DEFAULT          38400000
+#define CPUFREQ_NORMAL           CPUFREQ_DEFAULT
 
 /* FCLK */
 #define AS3525_FCLK_SEL          AS3525_CLK_PLLA
@@ -145,21 +138,8 @@
 #endif /* CONFIG_CPU == AS3525v2 */
 
 /* MCLK */
-#if CONFIG_CPU == AS3525v2
-/* on AMSv2 we can enable PLLB for MCLK to increase PCM sample rate accuracy
-   with no significant impact on battery life */
-#define AS3525_MCLK_SEL          AS3525_CLK_PLLB
-#else
 #define AS3525_MCLK_SEL          AS3525_CLK_PLLA
-#endif /* CONFIG_CPU == AS3525v2 */
-
-#if (AS3525_MCLK_SEL==AS3525_CLK_PLLA)
 #define AS3525_MCLK_FREQ         AS3525_PLLA_FREQ
-#elif (AS3525_MCLK_SEL==AS3525_CLK_PLLB)
-#define AS3525_MCLK_FREQ         AS3525_PLLB_FREQ
-#else
-#error Choose either PLLA or PLLB for MCLK!
-#endif
 
 /* PCLK */
 
diff --git a/firmware/target/arm/as3525/system-as3525.c b/firmware/target/arm/as3525/system-as3525.c
index 51b6755601..4de111d00f 100644
--- a/firmware/target/arm/as3525/system-as3525.c
+++ b/firmware/target/arm/as3525/system-as3525.c
@@ -306,8 +306,6 @@ void system_init(void)
 
     CGU_PERI |= CGU_ROM_ENABLE; /* needed for rebooting */
 
-    set_cpu_frequency(CPUFREQ_DEFAULT);
-
 #if 0 /* the GPIO clock is already enabled by the dualboot function */
     CGU_PERI |= CGU_GPIO_CLOCK_ENABLE;
 #endif
@@ -335,10 +333,8 @@ void system_init(void)
     ascodec_write_pmu(0x18, 1, 0x35);
     /* AVDD17:    set AVDD17 power supply to 2.5V */
     ascodec_write_pmu(0x18, 7, 0x31);
-#ifdef SANSA_CLIPZIP
-    /* CVDD2:     set CVDD2 power supply to 2.8V */
-    ascodec_write_pmu(0x17, 2, 0xF4);
-#endif
+    /* CVDD2:     set CVDD2 power supply (digital for DAC/SD/etc) to 2.65V */
+    ascodec_write_pmu(0x17, 2, 0x80 | 113);
 #else /* HAVE_AS3543 */
     ascodec_write(AS3514_CVDD_DCDC3, AS314_CP_DCDC3_SETTING);
 #endif /* HAVE_AS3543 */
@@ -460,23 +456,18 @@ void set_cpu_frequency(long frequency)
     }
 }
 #else   /* as3525v2  */
-/* FIXME : disabled for now, seems to cause buggy memory accesses
- * Disabling MMU or putting the function in uncached memory seems to help? */
 void set_cpu_frequency(long frequency)
 {
-    int oldstatus = disable_irq_save();
-
-    /* We only have 2 settings */
-    cpu_frequency = (frequency == CPUFREQ_MAX) ? frequency : CPUFREQ_NORMAL;
-
     if(frequency == CPUFREQ_MAX)
     {
-        /* Change PCLK while FCLK is low, so it doesn't go too high */
-        CGU_PERI = (CGU_PERI & ~(0xF << 2)) | (AS3525_PCLK_DIV0 << 2);
+        /* Set CVDD1 power supply */
+        /*ascodec_write_pmu(0x17, 1, 0x80 | 47);*/
 
         CGU_PROC = ((AS3525_FCLK_POSTDIV << 4) |
                     (AS3525_FCLK_PREDIV  << 2) |
                     AS3525_FCLK_SEL);
+
+        cpu_frequency = CPUFREQ_MAX;
     }
     else
     {
@@ -484,11 +475,17 @@ void set_cpu_frequency(long frequency)
                     (AS3525_FCLK_PREDIV  << 2) |
                     AS3525_FCLK_SEL);
 
-        /* Change PCLK after FCLK is low, so it doesn't go too high */
-        CGU_PERI = (CGU_PERI & ~(0xF << 2)) | (AS3525_PCLK_DIV0_UNBOOSTED << 2);
-    }
+        cpu_frequency = CPUFREQ_NORMAL;
 
-    restore_irq(oldstatus);
+        /* Set CVDD1 power supply */
+        /*
+#ifdef SANSA_CLIPZIP
+        ascodec_write_pmu(0x17, 1, 0x80 | 19);
+#else
+        ascodec_write_pmu(0x17, 1, 0x80 | 22);
+#endif
+        */
+    }
 }
 #endif