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_ */