Minor fixes in AT91 ADC module.

Improve documentation and fix macros in order to
always use a frequency compliant with ADC specifications.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3908 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/cfg/cfg_adc.h b/bertos/cfg/cfg_adc.h
index dd65e134e8f0ac3711f0bd8a929ee2b2c53089bc..35e5866188083612981dd9564c00c186b7d833e7 100644 (file)
--- a/bertos/cfg/cfg_adc.h
+++ b/bertos/cfg/cfg_adc.h
@@ -57,9 +57,12 @@
 
 /**
  * Clock Frequency for ADC conversion.
+ * This frequency will be rounded down to an integer
+ * submultiple of CPU_FREQ.
  *
  * $WIZ$ type = "int"
  * $WIZ$ supports = "at91"
+ * $WIZ$ max = 5000000
  */
 #define CONFIG_ADC_CLOCK        4800000UL
 
@@ -67,16 +70,16 @@
  * Minimum time for starting up a conversion [us].
  *
  * $WIZ$ type = "int"
- * $WIZ$ min = 0
+ * $WIZ$ min = 20
  * $WIZ$ supports = "at91"
  */
 #define CONFIG_ADC_STARTUP_TIME 20
 
 /**
- * Minimum time for sample and hold [us].
+ * Minimum time for sample and hold [ns].
  *
  * $WIZ$ type = "int"
- * $WIZ$ min = 0
+ * $WIZ$ min = 600
  * $WIZ$ supports = "at91"
  */
 #define CONFIG_ADC_SHTIME       834

diff --git a/bertos/cpu/arm/drv/adc_at91.c b/bertos/cpu/arm/drv/adc_at91.c
index fadaa4bebeec70a37fba9506af604ec1f05a3ecb..4ac358616a89a49821c20dfd1b620f7d8e54f360 100644 (file)
--- a/bertos/cpu/arm/drv/adc_at91.c
+++ b/bertos/cpu/arm/drv/adc_at91.c
@@ -184,6 +184,7 @@ void adc_hw_init(void)
        #endif
        /* \} */
 
+       LOG_INFO("Computed ADC_CLOCK %ld\n", ADC_COMPUTED_CLOCK);
        LOG_INFO("prescaler[%ld], stup[%ld], shtim[%ld]\n",ADC_COMPUTED_PRESCALER, ADC_COMPUTED_STARTUPTIME,  ADC_COMPUTED_SHTIME);
 
 
@@ -201,7 +202,7 @@ void adc_hw_init(void)
        ADC_MR &= ~ADC_SHTIME_MASK;
        ADC_MR |= ((ADC_COMPUTED_SHTIME << ADC_SHTIME_SHIFT) & ADC_SHTIME_MASK);
        LOG_INFO("shtime[%ld]\n", (ADC_COMPUTED_SHTIME << ADC_SHTIME_SHIFT) & ADC_SHTIME_MASK);
-
+       
        #if CONFIG_KERN
                //Register and enable irq for adc.
                adc_enable_irq();

diff --git a/bertos/cpu/arm/drv/adc_at91.h b/bertos/cpu/arm/drv/adc_at91.h
index 07ef6a40927cd99e98d302d9f9ccb5036d006635..2ec0cdb595af0f676a6ab3b2b13f91c4ad1f1f72 100644 (file)
--- a/bertos/cpu/arm/drv/adc_at91.h
+++ b/bertos/cpu/arm/drv/adc_at91.h
@@ -57,9 +57,10 @@
  * Macro for computing correct value to write into ADC
  * register.
  */
-#define ADC_COMPUTED_PRESCALER    ((CPU_FREQ/(2 * CONFIG_ADC_CLOCK)) - 1)
-#define ADC_COMPUTED_STARTUPTIME  (((CONFIG_ADC_STARTUP_TIME * CONFIG_ADC_CLOCK)/ 8000000UL) - 1)
-#define ADC_COMPUTED_SHTIME       (((CONFIG_ADC_SHTIME * CONFIG_ADC_CLOCK)/1000000000UL) - 1)
+#define ADC_COMPUTED_PRESCALER    (DIV_ROUNDUP(CPU_FREQ, 2 * CONFIG_ADC_CLOCK) - 1)
+#define ADC_COMPUTED_CLOCK        (CPU_FREQ / ((ADC_COMPUTED_PRESCALER + 1) * 2))
+#define ADC_COMPUTED_STARTUPTIME  (((CONFIG_ADC_STARTUP_TIME * ADC_COMPUTED_CLOCK) / 8000000UL) - 1)
+#define ADC_COMPUTED_SHTIME       ((uint32_t)((CONFIG_ADC_SHTIME * (uint64_t)ADC_COMPUTED_CLOCK) / 1000000000UL) - 1)
 
 /**
  * Init pins macro for adc.