static int hdq_read_byte()

in masters/omap_hdq.c [308:359]

• 42 lines of code
• 5 McCabe index (conditional complexity)

static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
{
	int ret = 0;
	u8 status;

	ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
	if (ret < 0) {
		ret = -EINTR;
		goto rtn;
	}

	if (pm_runtime_suspended(hdq_data->dev)) {
		ret = -EINVAL;
		goto out;
	}

	if (!(hdq_data->hdq_irqstatus & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
		hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
			OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO,
			OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
		/*
		 * The RX comes immediately after TX.
		 */
		wait_event_timeout(hdq_wait_queue,
				   (hdq_data->hdq_irqstatus
				    & (OMAP_HDQ_INT_STATUS_RXCOMPLETE |
				       OMAP_HDQ_INT_STATUS_TIMEOUT)),
				   OMAP_HDQ_TIMEOUT);
		status = hdq_reset_irqstatus(hdq_data,
					     OMAP_HDQ_INT_STATUS_RXCOMPLETE |
					     OMAP_HDQ_INT_STATUS_TIMEOUT);
		hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, 0,
			OMAP_HDQ_CTRL_STATUS_DIR);

		/* check irqstatus */
		if (!(status & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
			dev_dbg(hdq_data->dev, "timeout waiting for"
				" RXCOMPLETE, %x", status);
			ret = -ETIMEDOUT;
			goto out;
		}
	} else { /* interrupt had occurred before hdq_read_byte was called */
		hdq_reset_irqstatus(hdq_data, OMAP_HDQ_INT_STATUS_RXCOMPLETE);
	}
	/* the data is ready. Read it in! */
	*val = hdq_reg_in(hdq_data, OMAP_HDQ_RX_DATA);
out:
	mutex_unlock(&hdq_data->hdq_mutex);
rtn:
	return ret;

}