示例#1
0
文件: rf69.c 项目: val2k/linux
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
}
示例#2
0
文件: pi433_if.c 项目: avagin/linux
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;
}