From f6517f7816206f9d4509a21242f330aa59360119 Mon Sep 17 00:00:00 2001
From: mfm <github@mmone.de>
Date: Thu, 31 May 2018 11:14:28 +0200
Subject: [PATCH] stm32: adc common  v2: add circular dma mode

Tested only on the F3 so far.
---
 .../libopencm3/stm32/common/adc_common_v2.h   |  3 ++-
 lib/stm32/common/adc_common_v2.c              | 20 +++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/include/libopencm3/stm32/common/adc_common_v2.h b/include/libopencm3/stm32/common/adc_common_v2.h
index afe23c39..fe4095c8 100644
--- a/include/libopencm3/stm32/common/adc_common_v2.h
+++ b/include/libopencm3/stm32/common/adc_common_v2.h
@@ -205,7 +205,8 @@ bool adc_get_overrun_flag(uint32_t adc);
 void adc_clear_overrun_flag(uint32_t adc);
 uint32_t adc_read_regular(uint32_t adc);
 void adc_start_conversion_regular(uint32_t adc);
-
+void adc_enable_dma_circular_mode(uint32_t adc);
+void adc_disable_dma_circular_mode(uint32_t adc);
 END_DECLS
 
 #endif
diff --git a/lib/stm32/common/adc_common_v2.c b/lib/stm32/common/adc_common_v2.c
index fb22d273..5ad85c6a 100644
--- a/lib/stm32/common/adc_common_v2.c
+++ b/lib/stm32/common/adc_common_v2.c
@@ -389,4 +389,24 @@ void adc_start_conversion_regular(uint32_t adc)
 	ADC_CR(adc) |= ADC_CR_ADSTART;
 }
 
+/** @brief Enable circular mode for DMA transfers
+ *
+ * For this to work it needs to be ebabled on the DMA side as well.
+ *
+ * @param[in] adc Unsigned int32. ADC base address (@ref adc_reg_base)
+ */
+void adc_enable_dma_circular_mode(uint32_t adc)
+{
+	ADC_CFGR1(adc) |= ADC_CFGR1_DMACFG;
+}
+
+/** @brief Disable circular mode for DMA transfers
+ *
+ * @param[in] adc Unsigned int32. ADC base address (@ref adc_reg_base)
+ */
+void adc_disable_dma_circular_mode(uint32_t adc)
+{
+	ADC_CFGR1(adc) &= ~ADC_CFGR1_DMACFG;
+}
+
 /**@}*/