altos/stmf0: Re-implement fast ADC code for stmf0

[fw/altos] / src / stmf0 / ao_adc_fast.c

diff --git a/src/stmf0/ao_adc_fast.c b/src/stmf0/ao_adc_fast.c
index 5885ae4fba748379d22bb2f120f803a4952812d6..be9b5986778d51ff95310a1e72f2f9884bd33eb0 100644 (file)
--- a/src/stmf0/ao_adc_fast.c
+++ b/src/stmf0/ao_adc_fast.c
@@ -18,7 +18,10 @@
 #include <ao.h>
 #include <ao_adc_fast.h>
 
-static uint8_t                 ao_adc_done;
+uint16_t ao_adc_ring[AO_ADC_RING_SIZE];
+
+uint16_t ao_adc_ring_head, ao_adc_ring_tail;
+uint8_t ao_adc_running;
 
 /*
  * Callback from DMA ISR
@@ -28,22 +31,30 @@ static uint8_t                      ao_adc_done;
 static void ao_adc_dma_done(int index)
 {
        (void) index;
-       ao_adc_done = 1;
-       ao_wakeup(&ao_adc_done);
+       ao_adc_ring_head += AO_ADC_RING_CHUNK;
+       if (ao_adc_ring_head == AO_ADC_RING_SIZE)
+               ao_adc_ring_head = 0;
+       ao_adc_running = 0;
+       ao_wakeup(&ao_adc_ring_head);
+       ao_dma_done_transfer(STM_DMA_INDEX(STM_DMA_CHANNEL_ADC_1));
 }
 
-/*
- * Start the ADC sequence using the DMA engine
- */
 void
-ao_adc_read(uint16_t *dest, int len)
+_ao_adc_start(void)
 {
-       ao_adc_done = 0;
+       uint16_t        *buf;
+
+       if (ao_adc_running)
+               return;
+       if (_ao_adc_space() < AO_ADC_RING_CHUNK)
+               return;
+       ao_adc_running = 1;
+       buf = ao_adc_ring + ao_adc_ring_head;
        stm_adc.isr = 0;
        ao_dma_set_transfer(STM_DMA_INDEX(STM_DMA_CHANNEL_ADC_1),
                            &stm_adc.dr,
-                           dest,
-                           len,
+                           buf,
+                           AO_ADC_RING_CHUNK,
                            (0 << STM_DMA_CCR_MEM2MEM) |
                            (STM_DMA_CCR_PL_HIGH << STM_DMA_CCR_PL) |
                            (STM_DMA_CCR_MSIZE_16 << STM_DMA_CCR_MSIZE) |
@@ -56,16 +67,6 @@ ao_adc_read(uint16_t *dest, int len)
        ao_dma_start(STM_DMA_INDEX(STM_DMA_CHANNEL_ADC_1));
 
        stm_adc.cr |= (1 << STM_ADC_CR_ADSTART);
-       ao_arch_block_interrupts();
-       while (!ao_adc_done)
-               ao_sleep(&ao_adc_done);
-       ao_arch_release_interrupts();
-
-       ao_dma_done_transfer(STM_DMA_INDEX(STM_DMA_CHANNEL_ADC_1));
-
-       stm_adc.cr |= (1 << STM_ADC_CR_ADSTP);
-       while ((stm_adc.cr & (1 << STM_ADC_CR_ADSTP)) != 0)
-               ;
 }
 
 void
@@ -185,4 +186,5 @@ ao_adc_init(void)
        stm_syscfg.cfgr1 &= ~(1 << STM_SYSCFG_CFGR1_ADC_DMA_RMP);
 
        ao_dma_alloc(STM_DMA_INDEX(STM_DMA_CHANNEL_ADC_1));
+       ao_dma_set_isr(STM_DMA_INDEX(STM_DMA_CHANNEL_ADC_1), ao_adc_dma_done);
 }