3 files changed, 26 insertions, 2 deletions
diff --git a/src/stm/ao_adc_stm.c b/src/stm/ao_adc_stm.c
index d758e629..729551c4 100644
--- a/src/stm/ao_adc_stm.c
+++ b/src/stm/ao_adc_stm.c
@@ -221,5 +221,7 @@ ao_adc_init(void)
 	/* Clear any stale status bits */
 	stm_adc.sr = 0;
 	ao_adc_ready = 1;
+
+	ao_dma_alloc(STM_DMA_INDEX(STM_DMA_CHANNEL_ADC1));
 	ao_cmd_register(&ao_adc_cmds[0]);
 }
diff --git a/src/stm/ao_arch_funcs.h b/src/stm/ao_arch_funcs.h
index a42fe10f..7dc576d1 100644
--- a/src/stm/ao_arch_funcs.h
+++ b/src/stm/ao_arch_funcs.h
@@ -62,6 +62,9 @@ void
 ao_dma_abort(uint8_t index);
 
 void
+ao_dma_alloc(uint8_t index);
+
+void
 ao_dma_init(void);
 
 #endif /* _AO_ARCH_FUNCS_H_ */
diff --git a/src/stm/ao_dma_stm.c b/src/stm/ao_dma_stm.c
index 785235a8..21390748 100644
--- a/src/stm/ao_dma_stm.c
+++ b/src/stm/ao_dma_stm.c
@@ -26,6 +26,7 @@ struct ao_dma_config {
 uint8_t ao_dma_done[NUM_DMA];
 
 static struct ao_dma_config ao_dma_config[NUM_DMA];
+static uint8_t ao_dma_allocated[NUM_DMA];
 static uint8_t ao_dma_mutex[NUM_DMA];
 static uint8_t ao_dma_active;
 
@@ -60,7 +61,12 @@ ao_dma_set_transfer(uint8_t 		index,
 		    uint16_t		count,
 		    uint32_t		ccr)
 {
-	ao_mutex_get(&ao_dma_mutex[index]);
+	if (ao_dma_allocated[index]) {
+		if (ao_dma_mutex[index])
+			ao_panic(AO_PANIC_DMA);
+		ao_dma_mutex[index] = 1;
+	} else
+		ao_mutex_get(&ao_dma_mutex[index]);
 	ao_arch_critical(
 		if (ao_dma_active++ == 0)
 			stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_DMA1EN);
@@ -93,7 +99,10 @@ ao_dma_done_transfer(uint8_t index)
 		if (--ao_dma_active == 0)
 			stm_rcc.ahbenr &= ~(1 << STM_RCC_AHBENR_DMA1EN);
 		);
-	ao_mutex_put(&ao_dma_mutex[index]);
+	if (ao_dma_allocated[index])
+		ao_dma_mutex[index] = 0;
+	else
+		ao_mutex_put(&ao_dma_mutex[index]);
 }
 
 void
@@ -103,6 +112,14 @@ ao_dma_abort(uint8_t index)
 }
 
 void
+ao_dma_alloc(uint8_t index)
+{
+	if (ao_dma_allocated[index])
+		ao_panic(AO_PANIC_DMA);
+	ao_dma_allocated[index] = 1;
+}
+
+void
 ao_dma_init(void)
 {
 	int	index;
@@ -110,6 +127,8 @@ ao_dma_init(void)
 	for (index = 0; index < STM_NUM_DMA; index++) {
 		stm_nvic_set_enable(STM_ISR_DMA1_CHANNEL1_POS + index);
 		stm_nvic_set_priority(STM_ISR_DMA1_CHANNEL1_POS + index, 4);
+		ao_dma_allocated[index] = 0;
+		ao_dma_mutex[index] = 0;
 	}
 	
 }