From: batt <batt@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Wed, 9 Jun 2010 11:01:15 +0000 (+0000)
Subject: Minor fixes in AT91 ADC module.
X-Git-Tag: 2.5.0~9
X-Git-Url: https://codewiz.org/gitweb?p=bertos.git;a=commitdiff_plain;h=c860c4c4a186878d3623df87be5e6577c59ad31f

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 dd65e134..35e58661 100644
--- 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 fadaa4be..4ac35861 100644
--- 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 07ef6a40..2ec0cdb5 100644
--- 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.