static void r592_execute_tpc()

in host/r592.c [454:561]

• 79 lines of code
• 22 McCabe index (conditional complexity)

static void r592_execute_tpc(struct r592_device *dev)
{
	bool is_write;
	int len, error;
	u32 status, reg;

	if (!dev->req) {
		message("BUG: tpc execution without request!");
		return;
	}

	is_write = dev->req->tpc >= MS_TPC_SET_RW_REG_ADRS;
	len = dev->req->long_data ?
		dev->req->sg.length : dev->req->data_len;

	/* Ensure that FIFO can hold the input data */
	if (len > R592_LFIFO_SIZE) {
		message("IO: hardware doesn't support TPCs longer that 512");
		error = -ENOSYS;
		goto out;
	}

	if (!(r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_PRSNT)) {
		dbg("IO: refusing to send TPC because card is absent");
		error = -ENODEV;
		goto out;
	}

	dbg("IO: executing %s LEN=%d",
			memstick_debug_get_tpc_name(dev->req->tpc), len);

	/* Set IO direction */
	if (is_write)
		r592_set_reg_mask(dev, R592_IO, R592_IO_DIRECTION);
	else
		r592_clear_reg_mask(dev, R592_IO, R592_IO_DIRECTION);


	error = r592_test_fifo_empty(dev);
	if (error)
		goto out;

	/* Transfer write data */
	if (is_write) {
		error = r592_transfer_fifo_dma(dev);
		if (error == -EINVAL)
			error = r592_transfer_fifo_pio(dev);
	}

	if (error)
		goto out;

	/* Trigger the TPC */
	reg = (len << R592_TPC_EXEC_LEN_SHIFT) |
		(dev->req->tpc << R592_TPC_EXEC_TPC_SHIFT) |
			R592_TPC_EXEC_BIG_FIFO;

	r592_write_reg(dev, R592_TPC_EXEC, reg);

	/* Wait for TPC completion */
	status = R592_STATUS_RDY;
	if (dev->req->need_card_int)
		status |= R592_STATUS_CED;

	error = r592_wait_status(dev, status, status);
	if (error) {
		message("card didn't respond");
		goto out;
	}

	/* Test IO errors */
	error = r592_test_io_error(dev);
	if (error) {
		dbg("IO error");
		goto out;
	}

	/* Read data from FIFO */
	if (!is_write) {
		error = r592_transfer_fifo_dma(dev);
		if (error == -EINVAL)
			error = r592_transfer_fifo_pio(dev);
	}

	/* read INT reg. This can be shortened with shifts, but that way
		its more readable */
	if (dev->parallel_mode && dev->req->need_card_int) {

		dev->req->int_reg = 0;
		status = r592_read_reg(dev, R592_STATUS);

		if (status & R592_STATUS_P_CMDNACK)
			dev->req->int_reg |= MEMSTICK_INT_CMDNAK;
		if (status & R592_STATUS_P_BREQ)
			dev->req->int_reg |= MEMSTICK_INT_BREQ;
		if (status & R592_STATUS_P_INTERR)
			dev->req->int_reg |= MEMSTICK_INT_ERR;
		if (status & R592_STATUS_P_CED)
			dev->req->int_reg |= MEMSTICK_INT_CED;
	}

	if (error)
		dbg("FIFO read error");
out:
	dev->req->error = error;
	r592_clear_reg_mask(dev, R592_REG_MSC, R592_REG_MSC_LED);
	return;
}