altos-avr: Completely replace the spi slave code

[fw/altos] / src-avr / ao_spi_slave.c

diff --git a/src-avr/ao_spi_slave.c b/src-avr/ao_spi_slave.c
index 5f1990d5cd767bfdcac6cf218a616f385fc7e1ef..8e01f586ed5d959d16485cc8d0e47371291903dd 100644 (file)
--- a/src-avr/ao_spi_slave.c
+++ b/src-avr/ao_spi_slave.c
@@ -16,83 +16,85 @@
  */
 
 #include "ao.h"
+#include "ao_product.h"
 
-__xdata struct ao_fifo ao_spi_slave_rx_fifo;
-__xdata struct ao_fifo ao_spi_slave_tx_fifo;
+static struct ao_companion_command     ao_companion_command;
+static const struct ao_companion_setup ao_companion_setup = {
+       .board_id               = AO_idProduct_NUMBER,
+       .board_id_inverse       = ~AO_idProduct_NUMBER,
+       .update_period          = 50,
+       .channels               = NUM_ADC
+};
 
-static volatile uint8_t        ao_spi_slave_tx_started;
-
-static void
-ao_spi_slave_tx_start(void)
+static void ao_spi_slave_recv(void)
 {
-       if (!ao_spi_slave_tx_started && !ao_fifo_empty(ao_spi_slave_tx_fifo)) {
-               ao_spi_slave_tx_started = 1;
-               ao_fifo_remove(ao_spi_slave_tx_fifo, SPDR);
-       }
-}
+       uint8_t *buf;
+       uint8_t len;
 
-ISR(SPI_STC_vect)
-{
-       uint8_t spsr;
+       len = sizeof (ao_companion_command);
+       buf = (uint8_t *) &ao_companion_command;
+       while (len--) {
+               while (!(SPSR & (1 << SPIF)))
+                       ;
+               *buf++ = SPDR;
+       }
 
-       spsr = SPSR;
-       if (SPIF & (1 << SPIF)) {
-               uint8_t byte = SPDR;
-               if (!ao_fifo_full(ao_spi_slave_rx_fifo))
-                       ao_fifo_insert(ao_spi_slave_rx_fifo, byte);
-               ao_spi_slave_tx_started = 0;
-               ao_spi_slave_tx_start();
-               ao_wakeup(&ao_spi_slave_rx_fifo);
-               ao_wakeup(&ao_spi_slave_tx_fifo);
+       /* Figure out the outbound data */
+       switch (ao_companion_command.command) {
+       case AO_COMPANION_SETUP:
+               buf = (uint8_t *) &ao_companion_setup;
+               len = sizeof (ao_companion_setup);
+               break;
+       case AO_COMPANION_FETCH:
+               buf = (uint8_t *) &ao_adc_ring[ao_adc_ring_prev(ao_adc_head)].adc;
+               len = NUM_ADC * sizeof (uint16_t);
+               break;
+       default:
+               return;
        }
-}
 
-static void
-ao_spi_slave_put(uint8_t b) __critical
-{
-       cli();
-       while (ao_fifo_full(ao_spi_slave_tx_fifo))
-               ao_sleep(&ao_spi_slave_tx_fifo);
-       ao_fifo_insert(ao_spi_slave_tx_fifo, b);
-       ao_spi_slave_tx_start();
-       sei();
+       /* Send the outbound data */
+       while (len--) {
+               SPDR = *buf++;
+               while (!(SPSR & (1 << SPIF)))
+                       ;
+       }
+       (void) SPDR;
 }
 
-static uint8_t
-ao_spi_slave_get(void) __critical
-{
-       uint8_t b;
-
-       cli();
-       while (ao_fifo_empty(ao_spi_slave_rx_fifo))
-               ao_sleep(&ao_spi_slave_rx_fifo);
-       ao_fifo_remove(ao_spi_slave_rx_fifo, b);
-       sei();
-       return b;
-}
+static uint8_t ao_spi_slave_running;
 
-void
-ao_spi_slave_read(uint8_t *data, int len)
+ISR(PCINT0_vect)
 {
-       while (len--) {
-               ao_spi_slave_put(0);
-               *data++ = ao_spi_slave_get();
+       if ((PINB & (1 << PINB0)) == 0) {
+               if (!(PCMSK0 & (1 << PCINT1)))
+                       PCMSK0 |= (1 << PCINT1);
+               else {
+                       PCMSK0 &= ~(1 << PCINT1);
+                       cli();
+                       if (!ao_spi_slave_running) {
+                               ao_spi_slave_running = 1;
+                               ao_spi_slave_recv();
+                       }
+                       sei();
+               }
+       } else {
+               ao_spi_slave_running = 0;
        }
 }
 
-void
-ao_spi_slave_write(uint8_t *data, int len)
-{
-       while (len--) {
-               ao_spi_slave_put(*data++);
-               (void) ao_spi_slave_get();
-       }
+void ao_spi_slave_debug(void) {
+       printf ("slave running %d\n", ao_spi_slave_running);
 }
 
 void
 ao_spi_slave_init(void)
 {
-       SPCR = (1 << SPIE) |            /* Enable SPI interrupts */
+       PCMSK0 |= (1 << PCINT0);        /* Enable PCINT0 pin change */
+       PCICR |= (1 << PCIE0);          /* Enable pin change interrupt */
+
+       DDRB = (DDRB & 0xf0) | (1 << 3);
+       SPCR = (0 << SPIE) |            /* Disable SPI interrupts */
                (1 << SPE) |            /* Enable SPI */
                (0 << DORD) |           /* MSB first */
                (0 << MSTR) |           /* Slave mode */