From 7decfee86464f40465ac16eee700e7a688004d22 Mon Sep 17 00:00:00 2001
From: Simon Brummer <brummer.simon@googlemail.com>
Date: Tue, 25 Nov 2014 20:16:15 +0100
Subject: [PATCH] dac driver implementation squashed
---
boards/stm32f4discovery/Makefile.features | 3 +-
cpu/stm32f4/periph/dac.c | 115 +++++++++++++---------
drivers/include/periph/dac.h | 15 ++-
3 files changed, 77 insertions(+), 56 deletions(-)
diff --git a/boards/stm32f4discovery/Makefile.features b/boards/stm32f4discovery/Makefile.features
index 282e770a43a11..f7ed95610a9c3 100644
--- a/boards/stm32f4discovery/Makefile.features
+++ b/boards/stm32f4discovery/Makefile.features
@@ -1,2 +1 @@
-FEATURES_PROVIDED += periph_gpio periph_spi periph_i2c periph_pwm periph_random periph_adc cpp
-
+FEATURES_PROVIDED += periph_gpio periph_spi periph_i2c periph_pwm periph_random periph_adc periph_dac cpp
diff --git a/cpu/stm32f4/periph/dac.c b/cpu/stm32f4/periph/dac.c
index c833ee1ca987f..81b2d348ed68e 100644
--- a/cpu/stm32f4/periph/dac.c
+++ b/cpu/stm32f4/periph/dac.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2014 Freie Universität Berlin
+ * Copyright (C) 2014 Simon Brummer
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
@@ -13,7 +13,7 @@
* @file
* @brief Low-level DAC driver implementation
*
- * @author Simon Brummer(simon.brummer@haw-hamburg.de)
+ * @author Simon Brummer<simon.brummer@haw-hamburg.de>
*
* @}
*/
@@ -35,78 +35,87 @@ dac_config_t dac_config[DAC_NUMOF];
int8_t dac_init(dac_t dev, dac_precision_t precision)
{
-
DAC_TypeDef *dac = 0;
dac_poweron(dev);
switch (dev) {
#if DAC_0_EN
- case DAC_0:
- dac = DAC_0_DEV;
- DAC_0_PORT_CLKEN();
- // Set Mode to analoge out, disable Pullup Pulldown Resistors for both channels
- DAC_0_PORT->MODER |= (3 << (DAC_0_CH0_PIN * 2) | 3 << (DAC_0_CH1_PIN * 2));
- DAC_0_PORT->PUPDR &= ~(3 << (DAC_0_CH0_PIN * 2) | 3 << (DAC_0_CH1_PIN * 2));
- break;
+ case DAC_0:
+ dac = DAC_0_DEV;
+ DAC_0_PORT_CLKEN();
+ /* Set Mode to analoge out, disable Pullup Pulldown Resistors for both channels */
+ DAC_0_PORT->MODER |= (3 << (DAC_0_CH0_PIN * 2) | 3 << (DAC_0_CH1_PIN * 2));
+ DAC_0_PORT->PUPDR &= ~(3 << (DAC_0_CH0_PIN * 2) | 3 << (DAC_0_CH1_PIN * 2));
+ break;
#endif
+ default:
+ /* Unknown Device */
+ return -1;
}
- // Select Shift value to normalize given Value
+ /* Select Shift value to normalize given Value */
switch(precision) {
- case DAC_RES_6BIT:
- dac_config[dev].shift_mod = 0x06; // 2^6 << 6 = 2^12
- break;
- case DAC_RES_8BIT:
- dac_config[dev].shift_mod = 0x04; // 2^8 << 4 = 2^12
- break;
- case DAC_RES_10BIT:
- dac_config[dev].shift_mod = 0x02; // 2^10 << 2 = 2^12
- break;
- case DAC_RES_12BIT:
- dac_config[dev].shift_mod = 0x00; // 2^12 << 0 = 2^12
- break;
- // Not Supported Resolutions
- case DAC_RES_14BIT:
- case DAC_RES_16BIT:
- dac_poweroff(dev);
- return -1;
+ case DAC_RES_6BIT:
+ dac_config[dev].shift_mod = 0x06; /* 2^6 << 6 = 2^12 */
+ break;
+ case DAC_RES_8BIT:
+ dac_config[dev].shift_mod = 0x04; /* 2^8 << 4 = 2^12 */
+ break;
+ case DAC_RES_10BIT:
+ dac_config[dev].shift_mod = 0x02; /* 2^10 << 2 = 2^12 */
+ break;
+ case DAC_RES_12BIT:
+ dac_config[dev].shift_mod = 0x00; /* 2^12 << 0 = 2^12 */
+ break;
+ /* Not Supported Resolutions */
+ case DAC_RES_14BIT:
+ case DAC_RES_16BIT:
+ default:
+ dac_poweroff(dev);
+ return -2;
break;
}
- // Enable Channels, Clear Output
+ /* Enable Channels, Clear Output */
dac->CR = 0;
dac->CR |= (DAC_CR_EN1 | DAC_CR_EN2);
dac->DHR12R1 = 0;
dac->DHR12R2 = 0;
return 0;
-
}
int8_t dac_write(dac_t dev, uint8_t channel, uint16_t value)
{
- DAC_TypeDef *dac = 0;
- uint16_t val = value << dac_config[dev].shift_mod;
+ DAC_TypeDef* __attribute__((unused)) dac = 0;
+ uint16_t __attribute__((unused)) val = value << dac_config[dev].shift_mod;
switch(dev){
#if DAC_0_EN
case DAC_0:
dac = DAC_0_DEV;
- // Check if given value is in Range.
if( DAC_MAX_12BIT < val ){
- return -1;
+ /* Value out of Range */
+ return -3;
}
switch(channel){
- case 0: dac->DHR12R1 = val; break;
- case 1: dac->DHR12R2 = val; break;
- // Unknown Channel
- default:
- return -2;
+ case 0:
+ dac->DHR12R1 = val;
+ break;
+ case 1:
+ dac->DHR12R2 = val;
+ break;
+ /* Invalid Channel */
+ default:
+ return -2;
}
break;
#endif
+ /* Unknown Device */
+ default:
+ return -1;
}
return 0;
}
@@ -115,31 +124,39 @@ int8_t dac_poweron(dac_t dev)
{
switch (dev){
#if DAC_0_EN
- case DAC_0:
- DAC_0_CLKEN();
- return 0;
+ case DAC_0:
+ DAC_0_CLKEN();
+ break;
#endif
+ default:
+ /* Unknown Device */
+ return -1;
}
- return -1;
+ return 0;
}
int8_t dac_poweroff(dac_t dev)
{
switch (dev) {
#if DAC_0_EN
- case DAC_0:
- DAC_0_CLKDIS();
- return 0;
+ case DAC_0:
+ DAC_0_CLKDIS();
+ break;
#endif
+ default:
+ /* Unknown Device */
+ return -1;
}
- return -1;
+ return 0;
}
-uint16_t dac_map(dac_t dev, int value, int min, int max){
+uint16_t dac_map(dac_t dev, int value, int min, int max)
+{
return dac_mapf(dev, (int) value, (int) min, (int) max);
}
-uint16_t dac_mapf(dac_t dev, float value, float min, float max){
+uint16_t dac_mapf(dac_t dev, float value, float min, float max)
+{
uint16_t val_12_bit = ((value - min) * DAC_MAX_12BIT)/(max-min);
return val_12_bit >> dac_config[dev].shift_mod;
}
diff --git a/drivers/include/periph/dac.h b/drivers/include/periph/dac.h
index eeda6e2e7bcd9..b673769bd529f 100644
--- a/drivers/include/periph/dac.h
+++ b/drivers/include/periph/dac.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2014 Freie Universität Berlin
+ * Copyright (C) 2014 Simon Brummer
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
@@ -74,7 +74,8 @@ typedef enum {
* @param[in] precision the precision to use for conversion
*
* @return 0 on success
- * @return -1 on precision not available
+ * @return -1 on unknown DAC Device
+ * @return -2 on precision not available
*/
int8_t dac_init(dac_t dev, dac_precision_t precision);
@@ -86,8 +87,9 @@ int8_t dac_init(dac_t dev, dac_precision_t precision);
* @param[in] value the value to write onto DAC.
*
* @return 0 on success
- * @return -1 if value is out of range.
+ * @return -1 on unknown DAC Device
* @return -2 on invalid channel
+ * @return -3 if value is out of range.
*/
int8_t dac_write(dac_t dev, uint8_t channel, uint16_t value);
@@ -124,7 +126,7 @@ int8_t dac_poweroff(dac_t dev);
* @param[in] min the lower bound of the target interval
* @param[in] max the upper bound of the target interval
*
- * @return the mapped value
+ * @return the mapped value, in valid DAC range
*/
uint16_t dac_map(dac_t dev, int value, int min, int max);
@@ -138,11 +140,14 @@ uint16_t dac_map(dac_t dev, int value, int min, int max);
* @param[in] min the lower bound of the target interval
* @param[in] max the upper bound of the target interval
*
- * @return the mapped value
+ * @return the mapped value, in valid DAC range
*/
uint16_t dac_mapf(dac_t dev, float value, float min, float max);
#endif/* DAC_NUMOF */
+#ifdef __cplusplus
+}
+#endif
#endif /* __DAC_H */
/** @} */