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

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

diff --git a/src/stmf0/ao_adc_fast.h b/src/stmf0/ao_adc_fast.h
index a2408d147914c3b471d3db455e50013beebb27a3..eec4550539390a75c14ee3e4ea90ced163d0bafe 100644 (file)
--- a/src/stmf0/ao_adc_fast.h
+++ b/src/stmf0/ao_adc_fast.h
@@ -24,4 +24,66 @@ ao_adc_read(uint16_t *dest, int len);
 void
 ao_adc_init(void);
 
 void
 ao_adc_init(void);
 

+/* Total ring size in samples */
+#define AO_ADC_RING_SIZE       256
+/* Number of samples fetched per ao_adc_start call */
+#define AO_ADC_RING_CHUNK      (AO_ADC_RING_SIZE >> 1)
+
+extern uint16_t        ao_adc_ring[AO_ADC_RING_SIZE];
+
+#define ao_adc_ring_step(pos,inc)      (((pos) + (inc)) & (AO_ADC_RING_SIZE - 1))
+
+extern uint16_t        ao_adc_ring_head, ao_adc_ring_tail;
+extern uint8_t ao_adc_running;
+
+void
+_ao_adc_start(void);
+
+static inline uint16_t
+_ao_adc_remain(void)
+{
+       if (ao_adc_ring_tail > ao_adc_ring_head)
+               return AO_ADC_RING_SIZE - ao_adc_ring_tail;
+       return ao_adc_ring_head - ao_adc_ring_tail;
+}
+
+static inline uint16_t
+_ao_adc_space(void)
+{
+       if (ao_adc_ring_head == ao_adc_ring_tail)
+               return AO_ADC_RING_SIZE;
+       if (ao_adc_ring_head > ao_adc_ring_tail)
+               return AO_ADC_RING_SIZE - ao_adc_ring_head;
+       return ao_adc_ring_tail - ao_adc_ring_head;
+}
+
+static inline uint16_t *
+ao_adc_get(uint16_t n)
+{
+       if (ao_adc_ring_tail + n > AO_ADC_RING_SIZE)
+               ao_panic(AO_PANIC_ADC);
+       ao_arch_block_interrupts();
+       while (_ao_adc_remain() < n) {
+               if (!ao_adc_running)
+                       _ao_adc_start();
+               ao_sleep(&ao_adc_ring_head);
+       }
+       ao_arch_release_interrupts();
+       return &ao_adc_ring[ao_adc_ring_tail];
+}
+
+static inline void
+ao_adc_ack(uint16_t n)
+{
+       if (ao_adc_ring_tail + n > AO_ADC_RING_SIZE)
+               ao_panic(AO_PANIC_ADC);
+       ao_arch_block_interrupts();
+       ao_adc_ring_tail += n;
+       if (ao_adc_ring_tail == AO_ADC_RING_SIZE)
+               ao_adc_ring_tail = 0;
+       if (!ao_adc_running && _ao_adc_space() >= AO_ADC_RING_CHUNK)
+               _ao_adc_start();
+       ao_arch_release_interrupts();
+}
+

 #endif /* _AO_ADC_FAST_H_ */
 #endif /* _AO_ADC_FAST_H_ */