#define AO_PANIC_BUFIO 15 /* Mis-using bufio API */
#define AO_PANIC_EXTI 16 /* Mis-using exti API */
#define AO_PANIC_FAST_TIMER 17 /* Mis-using fast timer API */
+#define AO_PANIC_ADC 18 /* Mis-using ADC interface */
#define AO_PANIC_SELF_TEST_CC1120 0x40 | 1 /* Self test failure */
#define AO_PANIC_SELF_TEST_HMC5883 0x40 | 2 /* Self test failure */
#define AO_PANIC_SELF_TEST_MPU6000 0x40 | 3 /* Self test failure */
#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
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) |
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
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);
}
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_ */
ao_trng_fetch(void)
{
static uint16_t *buffer[2];
- static uint32_t adc_in[AO_USB_IN_SIZE/2]; /* twice as many as we need */
uint32_t kbytes = 1;
uint32_t count;
int usb_buf_id;
ao_led_on(AO_LED_GREEN);
while (count--) {
- ao_adc_read((uint16_t *) adc_in, AO_USB_IN_SIZE);
- rnd = adc_in;
buf = buffer[usb_buf_id];
+// printf ("before get: head %3d tail %3d running %d\n", ao_adc_ring_head, ao_adc_ring_tail, ao_adc_running); flush();
+ rnd = (uint32_t *) ao_adc_get(AO_USB_IN_SIZE); /* one 16-bit value per output byte */
+// printf ("after get: head %3d tail %3d running %d\n", ao_adc_ring_head, ao_adc_ring_tail, ao_adc_running); flush();
for (i = 0; i < 32; i++)
*buf++ = ao_crc_in_32_out_16(*rnd++);
+ ao_adc_ack(AO_USB_IN_SIZE);
+// printf ("after ack: head %3d tail %3d running %d\n", ao_adc_ring_head, ao_adc_ring_tail, ao_adc_running); flush();
ao_led_toggle(AO_LED_GREEN|AO_LED_RED);
ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE);
ao_led_toggle(AO_LED_GREEN|AO_LED_RED);
usb_buf_id = 1-usb_buf_id;
}
ao_led_off(AO_LED_GREEN|AO_LED_RED);
- ao_usb_flush();
+ flush();
}
static const struct ao_cmds usbtrng_cmds[] = {