From e94d1b0ab0042b71a4e0c7609b412185c53dcded Mon Sep 17 00:00:00 2001
From: Marcin Bukat <marcin.bukat@gmail.com>
Date: Tue, 24 Jan 2012 11:53:22 +0100
Subject: MPIO HD200/HD300: Decrease ADC scanrate.

The adclk is decreased 4x. This solves problems with battery
readout drop during system startup.

Change-Id: I46d7c4b9ffcfdc812a6dd2a932c9e397d33c1168
---
 firmware/target/coldfire/mpio/adc-mpio.c    | 30 +++++------------------------
 firmware/target/coldfire/mpio/system-mpio.c | 12 ++++++------
 2 files changed, 11 insertions(+), 31 deletions(-)

(limited to 'firmware/target')

diff --git a/firmware/target/coldfire/mpio/adc-mpio.c b/firmware/target/coldfire/mpio/adc-mpio.c
index 92b9479279..4c796d5d15 100644
--- a/firmware/target/coldfire/mpio/adc-mpio.c
+++ b/firmware/target/coldfire/mpio/adc-mpio.c
@@ -28,17 +28,11 @@
 
 volatile unsigned short adc_data[NUM_ADC_CHANNELS] IBSS_ATTR;
 
-/* Reading takes 4096 adclk ticks
- * 1) tick task is created that enables ADC interrupt
- * 2) On interrupt single channel is readed and
- *    ADC is prepared for next channel
- * 3) When all 4 channels are scanned ADC interrupt is disabled
- */
-
 void ADC(void) __attribute__ ((interrupt_handler,section(".icode")));
 void ADC(void)
 {
     static unsigned char channel IBSS_ATTR;
+
     /* read current value */
     adc_data[(channel&0x03)] = ADVALUE;
 
@@ -48,15 +42,10 @@ void ADC(void)
      * ADCONFIG is 16bit wide so we have to shift data by 16bits left
      * thats why we shift <<24 instead of <<8
      */
-
     channel++;
 
     and_l(~(0x03<<24),&ADCONFIG);
     or_l( (((channel&0x03) << 8 )|(1<<7))<<16, &ADCONFIG);
-    
-    if ( (channel & 0x03) == 0 )
-        /* disable ADC interrupt */
-        and_l((~(1<<6))<<16,&ADCONFIG);
 }
 
 unsigned short adc_scan(int channel)
@@ -65,12 +54,6 @@ unsigned short adc_scan(int channel)
     return adc_data[(channel&0x03)];
 }
 
-void adc_tick(void)
-{
-    /* enable ADC interrupt */
-    or_l( ((1<<6))<<16, &ADCONFIG);
-}
-
 void adc_init(void)
 {
     /* GPIO38 GPIO39 */
@@ -79,19 +62,16 @@ void adc_init(void)
     /* ADOUT_SEL = 01
      * SOURCE SELECT = 000
      * CLEAR INTERRUPT FLAG
-     * ENABLE INTERRUPT = 0
+     * ENABLE INTERRUPT = 1
      * ADOUT_DRIVE = 00
-     * ADCLK_SEL = 011 (busclk/8)
+     * ADCLK_SEL = 011 (busclk/64)
      */
 
-    ADCONFIG = (1<<10)|(1<<8)|(1<<7)|0x03;
+    ADCONFIG = (1<<10)|(1<<7)|(1<<6)|0x06;
 
     /* ADC interrupt level 4.0 */
     or_l((4<<28), &INTPRI8);
 
-    /* create tick task which enables ADC interrupt */
-    tick_add_task(adc_tick);
-
     /* let the interrupt handler fill readout array */
-    sleep(2);
+    sleep(HZ/10);
 }
diff --git a/firmware/target/coldfire/mpio/system-mpio.c b/firmware/target/coldfire/mpio/system-mpio.c
index ef291dbe0d..846f77b56e 100644
--- a/firmware/target/coldfire/mpio/system-mpio.c
+++ b/firmware/target/coldfire/mpio/system-mpio.c
@@ -80,8 +80,8 @@ void cf_set_cpu_frequency(long frequency)
                     /* BUFEN2 enable on /CS2 | CS2Post 1 clock| CS2Pre 3 clocks*/
         IDECONFIG2 = (1<<18)|(1<<16)|(1<<8)|(1<<0); /* TA /CS2 enable + CS2wait */
 
-        and_l(~(0x07<<16), &ADCONFIG);
-        or_l((0x05)<<16, &ADCONFIG); /* adclk = busclk/32 */
+        and_l(~(0x0f<<16), &ADCONFIG);
+        or_l((0x08)<<16, &ADCONFIG); /* adclk = busclk/256 */
         break;
 
     case CPUFREQ_NORMAL:
@@ -100,8 +100,8 @@ void cf_set_cpu_frequency(long frequency)
         IDECONFIG1 = (1<<28)|(1<<20)|(1<<18)|(1<<13)|(1<<10);
         IDECONFIG2 = (1<<18)|(1<<16);
 
-        and_l(~(0x07<<16), &ADCONFIG);
-        or_l((0x03)<<16, &ADCONFIG); /* adclk = busclk/8 */
+        and_l(~(0x0f<<16), &ADCONFIG);
+        or_l((0x06)<<16, &ADCONFIG); /* adclk = busclk/64 */
         break;
 
     default:
@@ -118,8 +118,8 @@ void cf_set_cpu_frequency(long frequency)
         IDECONFIG1 = (1<<28)|(1<<20)|(1<<18)|(1<<13)|(1<<10);
         IDECONFIG2 = (1<<18)|(1<<16);
 
-        and_l(~(0x07<<16), &ADCONFIG);
-        or_l((0x01)<<16, &ADCONFIG); /* adclk = busclk/2 */
+        and_l(~(0x0f<<16), &ADCONFIG);
+        or_l((0x04)<<16, &ADCONFIG); /* adclk = busclk/16 */
         break;
     }
 }
-- 
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