int rf69_set_fifo_threshold(struct spi_device *spi, u8 threshold)
{
int retval;
#ifdef DEBUG
dev_dbg(&spi->dev, "set: fifo threshold");
#endif
// check input value
if (threshold & 0x80) {
dev_dbg(&spi->dev, "set: illegal input param");
return -EINVAL;
}
// write value
retval = WRITE_REG(REG_FIFO_THRESH, (READ_REG(REG_FIFO_THRESH) & ~MASK_FIFO_THRESH_VALUE) | threshold);
if (retval)
return retval;
// access the fifo to activate new threshold
return rf69_read_fifo(spi, (u8 *)&retval, 1); // retval used as buffer
}
static int
pi433_receive(void *data)
{
struct pi433_device *dev = data;
struct spi_device *spi = dev->spi;
int bytes_to_read, bytes_total;
int retval;
dev->interrupt_rx_allowed = false;
/* wait for any tx to finish */
dev_dbg(dev->dev, "rx: going to wait for any tx to finish");
retval = wait_event_interruptible(dev->rx_wait_queue, !dev->tx_active);
if (retval) {
/* wait was interrupted */
dev->interrupt_rx_allowed = true;
wake_up_interruptible(&dev->tx_wait_queue);
return retval;
}
/* prepare status vars */
dev->free_in_fifo = FIFO_SIZE;
dev->rx_position = 0;
dev->rx_bytes_dropped = 0;
/* setup radio module to listen for something "in the air" */
retval = pi433_start_rx(dev);
if (retval)
return retval;
/* now check RSSI, if low wait for getting high (RSSI interrupt) */
while (!rf69_get_flag(dev->spi, rssi_exceeded_threshold)) {
/* allow tx to interrupt us while waiting for high RSSI */
dev->interrupt_rx_allowed = true;
wake_up_interruptible(&dev->tx_wait_queue);
/* wait for RSSI level to become high */
dev_dbg(dev->dev, "rx: going to wait for high RSSI level");
retval = wait_event_interruptible(dev->rx_wait_queue,
rf69_get_flag(dev->spi,
rssi_exceeded_threshold));
if (retval) /* wait was interrupted */
goto abort;
dev->interrupt_rx_allowed = false;
/* cross check for ongoing tx */
if (!dev->tx_active)
break;
}
/* configure payload ready irq */
retval = rf69_set_dio_mapping(spi, DIO0, DIO_PAYLOAD_READY);
if (retval < 0)
goto abort;
dev->irq_state[DIO0] = DIO_PAYLOAD_READY;
irq_set_irq_type(dev->irq_num[DIO0], IRQ_TYPE_EDGE_RISING);
/* fixed or unlimited length? */
if (dev->rx_cfg.fixed_message_length != 0) {
if (dev->rx_cfg.fixed_message_length > dev->rx_buffer_size) {
retval = -1;
goto abort;
}
bytes_total = dev->rx_cfg.fixed_message_length;
dev_dbg(dev->dev, "rx: msg len set to %d by fixed length",
bytes_total);
} else {
bytes_total = dev->rx_buffer_size;
dev_dbg(dev->dev, "rx: msg len set to %d as requested by read",
bytes_total);
}
/* length byte enabled? */
if (dev->rx_cfg.enable_length_byte == OPTION_ON) {
retval = wait_event_interruptible(dev->fifo_wait_queue,
dev->free_in_fifo < FIFO_SIZE);
if (retval) /* wait was interrupted */
goto abort;
rf69_read_fifo(spi, (u8 *)&bytes_total, 1);
if (bytes_total > dev->rx_buffer_size) {
retval = -1;
goto abort;
}
dev->free_in_fifo++;
dev_dbg(dev->dev, "rx: msg len reset to %d due to length byte",
bytes_total);
}
/* address byte enabled? */
if (dev->rx_cfg.enable_address_filtering != filtering_off) {
u8 dummy;
bytes_total--;
retval = wait_event_interruptible(dev->fifo_wait_queue,
dev->free_in_fifo < FIFO_SIZE);
if (retval) /* wait was interrupted */
goto abort;
rf69_read_fifo(spi, &dummy, 1);
dev->free_in_fifo++;
dev_dbg(dev->dev, "rx: address byte stripped off");
}
/* get payload */
while (dev->rx_position < bytes_total) {
if (!rf69_get_flag(dev->spi, payload_ready)) {
retval = wait_event_interruptible(dev->fifo_wait_queue,
dev->free_in_fifo < FIFO_SIZE);
if (retval) /* wait was interrupted */
goto abort;
}
/* need to drop bytes or acquire? */
if (dev->rx_bytes_to_drop > dev->rx_bytes_dropped)
bytes_to_read = dev->rx_bytes_to_drop -
dev->rx_bytes_dropped;
else
bytes_to_read = bytes_total - dev->rx_position;
/* access the fifo */
if (bytes_to_read > FIFO_SIZE - dev->free_in_fifo)
bytes_to_read = FIFO_SIZE - dev->free_in_fifo;
retval = rf69_read_fifo(spi,
&dev->rx_buffer[dev->rx_position],
bytes_to_read);
if (retval) /* read failed */
goto abort;
dev->free_in_fifo += bytes_to_read;
/* adjust status vars */
if (dev->rx_bytes_to_drop > dev->rx_bytes_dropped)
dev->rx_bytes_dropped += bytes_to_read;
else
dev->rx_position += bytes_to_read;
}
/* rx done, wait was interrupted or error occurred */
abort:
dev->interrupt_rx_allowed = true;
if (rf69_set_mode(dev->spi, standby))
pr_err("rf69_set_mode(): radio module failed to go standby\n");
wake_up_interruptible(&dev->tx_wait_queue);
if (retval)
return retval;
else
return bytes_total;
}