static int __devinit xilinx_spi_of_probe(struct of_device *ofdev,
	const struct of_device_id *match)
{
	struct spi_master *master;
	struct xspi_platform_data *pdata;
	struct resource r_mem;
	struct resource r_irq;
	int rc = 0;
	const u32 *prop;
	int len;

	rc = of_address_to_resource(ofdev->node, 0, &r_mem);
	if (rc) {
		dev_warn(&ofdev->dev, "invalid address\n");
		return rc;
	}

	rc = of_irq_to_resource(ofdev->node, 0, &r_irq);
	if (rc == NO_IRQ) {
		dev_warn(&ofdev->dev, "no IRQ found\n");
		return -ENODEV;
	}

	ofdev->dev.platform_data =
		kzalloc(sizeof(struct xspi_platform_data), GFP_KERNEL);
	pdata = ofdev->dev.platform_data;
	if (!pdata)
		return -ENOMEM;

	/* number of slave select bits is required */
	prop = of_get_property(ofdev->node, "xlnx,num-ss-bits", &len);
	if (!prop || len < sizeof(*prop)) {
		dev_warn(&ofdev->dev, "no 'xlnx,num-ss-bits' property\n");
		return -EINVAL;
	}
	pdata->num_chipselect = *prop;
	pdata->bits_per_word = 8;
	master = xilinx_spi_init(&ofdev->dev, &r_mem, r_irq.start, -1);
	if (!master)
		return -ENODEV;

	dev_set_drvdata(&ofdev->dev, master);

	/* Add any subnodes on the SPI bus */
	of_register_spi_devices(master, ofdev->node);

	return 0;
}
static int __init xilinx_spi_of_probe(struct of_device *ofdev,
					const struct of_device_id *match)
{
	struct spi_master *master;
	struct xilinx_spi *xspi;
	struct resource r_irq_struct;
	struct resource r_mem_struct;

	struct resource *r_irq = &r_irq_struct;
	struct resource *r_mem = &r_mem_struct;
	int rc = 0;
	const u32 *prop;
	int len;

	/* Get resources(memory, IRQ) associated with the device */
	master = spi_alloc_master(&ofdev->dev, sizeof(struct xilinx_spi));

	if (master == NULL) {
		return -ENOMEM;
	}

	dev_set_drvdata(&ofdev->dev, master);

	rc = of_address_to_resource(ofdev->node, 0, r_mem);
	if (rc) {
		dev_warn(&ofdev->dev, "invalid address\n");
		goto put_master;
	}

	rc = of_irq_to_resource(ofdev->node, 0, r_irq);
	if (rc == NO_IRQ) {
		dev_warn(&ofdev->dev, "no IRQ found\n");
		goto put_master;
	}

	xspi = spi_master_get_devdata(master);
	xspi->bitbang.master = spi_master_get(master);
	xspi->bitbang.chipselect = xilinx_spi_chipselect;
	xspi->bitbang.setup_transfer = xilinx_spi_setup_transfer;
	xspi->bitbang.txrx_bufs = xilinx_spi_txrx_bufs;
	xspi->bitbang.master->setup = xilinx_spi_setup;
	init_completion(&xspi->done);

	xspi->irq = r_irq->start;

	if (!request_mem_region(r_mem->start,
			r_mem->end - r_mem->start + 1, XILINX_SPI_NAME)) {
		rc = -ENXIO;
		dev_warn(&ofdev->dev, "memory request failure\n");
		goto put_master;
	}

	xspi->regs = ioremap(r_mem->start, r_mem->end - r_mem->start + 1);
	if (xspi->regs == NULL) {
		rc = -ENOMEM;
		dev_warn(&ofdev->dev, "ioremap failure\n");
		goto put_master;
	}
	xspi->irq = r_irq->start;

	/* dynamic bus assignment */
	master->bus_num = -1;

	/* number of slave select bits is required */
	prop = of_get_property(ofdev->node, "xlnx,num-ss-bits", &len);
	if (!prop || len < sizeof(*prop)) {
		dev_warn(&ofdev->dev, "no 'xlnx,num-ss-bits' property\n");
		goto put_master;
	}
	master->num_chipselect = *prop;

	/* SPI controller initializations */
	xspi_init_hw(xspi->regs);

	/* Register for SPI Interrupt */
	rc = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi);
	if (rc != 0) {
		dev_warn(&ofdev->dev, "irq request failure: %d\n", xspi->irq);
		goto unmap_io;
	}

	rc = spi_bitbang_start(&xspi->bitbang);
	if (rc != 0) {
		dev_err(&ofdev->dev, "spi_bitbang_start FAILED\n");
		goto free_irq;
	}

	dev_info(&ofdev->dev, "at 0x%08X mapped to 0x%08X, irq=%d\n",
			(unsigned int)r_mem->start, (u32)xspi->regs, xspi->irq);

	/* Add any subnodes on the SPI bus */
	of_register_spi_devices(master, ofdev->node);

	return rc;

free_irq:
	free_irq(xspi->irq, xspi);
unmap_io:
	iounmap(xspi->regs);
put_master:
	spi_master_put(master);
	return rc;
}
/*
 * OF Platform Bus Binding
 */
static int __devinit mpc52xx_spi_probe(struct of_device *op,
				       const struct of_device_id *match)
{
	struct spi_master *master;
	struct mpc52xx_spi *ms;
	void __iomem *regs;
	u8 ctrl1;
	int rc, i = 0;
	int gpio_cs;

	/* MMIO registers */
	dev_dbg(&op->dev, "probing mpc5200 SPI device\n");
	regs = of_iomap(op->node, 0);
	if (!regs)
		return -ENODEV;

	/* initialize the device */
	ctrl1 = SPI_CTRL1_SPIE | SPI_CTRL1_SPE | SPI_CTRL1_MSTR;
	out_8(regs + SPI_CTRL1, ctrl1);
	out_8(regs + SPI_CTRL2, 0x0);
	out_8(regs + SPI_DATADIR, 0xe);	/* Set output pins */
	out_8(regs + SPI_PORTDATA, 0x8);	/* Deassert /SS signal */

	/* Clear the status register and re-read it to check for a MODF
	 * failure.  This driver cannot currently handle multiple masters
	 * on the SPI bus.  This fault will also occur if the SPI signals
	 * are not connected to any pins (port_config setting) */
	in_8(regs + SPI_STATUS);
	out_8(regs + SPI_CTRL1, ctrl1);

	in_8(regs + SPI_DATA);
	if (in_8(regs + SPI_STATUS) & SPI_STATUS_MODF) {
		dev_err(&op->dev, "mode fault; is port_config correct?\n");
		rc = -EIO;
		goto err_init;
	}

	dev_dbg(&op->dev, "allocating spi_master struct\n");
	master = spi_alloc_master(&op->dev, sizeof *ms);
	if (!master) {
		rc = -ENOMEM;
		goto err_alloc;
	}

	master->bus_num = -1;
	master->setup = mpc52xx_spi_setup;
	master->transfer = mpc52xx_spi_transfer;
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;

	dev_set_drvdata(&op->dev, master);

	ms = spi_master_get_devdata(master);
	ms->master = master;
	ms->regs = regs;
	ms->irq0 = irq_of_parse_and_map(op->node, 0);
	ms->irq1 = irq_of_parse_and_map(op->node, 1);
	ms->state = mpc52xx_spi_fsmstate_idle;
	ms->ipb_freq = mpc5xxx_get_bus_frequency(op->node);
	ms->gpio_cs_count = of_gpio_count(op->node);
	if (ms->gpio_cs_count > 0) {
		master->num_chipselect = ms->gpio_cs_count;
		ms->gpio_cs = kmalloc(ms->gpio_cs_count * sizeof(unsigned int),
				GFP_KERNEL);
		if (!ms->gpio_cs) {
			rc = -ENOMEM;
			goto err_alloc;
		}

		for (i = 0; i < ms->gpio_cs_count; i++) {
			gpio_cs = of_get_gpio(op->node, i);
			if (gpio_cs < 0) {
				dev_err(&op->dev,
					"could not parse the gpio field "
					"in oftree\n");
				rc = -ENODEV;
				goto err_gpio;
			}

			rc = gpio_request(gpio_cs, dev_name(&op->dev));
			if (rc) {
				dev_err(&op->dev,
					"can't request spi cs gpio #%d "
					"on gpio line %d\n", i, gpio_cs);
				goto err_gpio;
			}

			gpio_direction_output(gpio_cs, 1);
			ms->gpio_cs[i] = gpio_cs;
		}
	} else {
		master->num_chipselect = 1;
	}

	spin_lock_init(&ms->lock);
	INIT_LIST_HEAD(&ms->queue);
	INIT_WORK(&ms->work, mpc52xx_spi_wq);

	/* Decide if interrupts can be used */
	if (ms->irq0 && ms->irq1) {
		rc = request_irq(ms->irq0, mpc52xx_spi_irq, 0,
				  "mpc5200-spi-modf", ms);
		rc |= request_irq(ms->irq1, mpc52xx_spi_irq, 0,
				  "mpc5200-spi-spif", ms);
		if (rc) {
			free_irq(ms->irq0, ms);
			free_irq(ms->irq1, ms);
			ms->irq0 = ms->irq1 = 0;
		}
	} else {
		/* operate in polled mode */
		ms->irq0 = ms->irq1 = 0;
	}

	if (!ms->irq0)
		dev_info(&op->dev, "using polled mode\n");

	dev_dbg(&op->dev, "registering spi_master struct\n");
	rc = spi_register_master(master);
	if (rc)
		goto err_register;

	of_register_spi_devices(master, op->node);
	dev_info(&ms->master->dev, "registered MPC5200 SPI bus\n");

	return rc;

 err_register:
	dev_err(&ms->master->dev, "initialization failed\n");
	spi_master_put(master);
 err_gpio:
	while (i-- > 0)
		gpio_free(ms->gpio_cs[i]);

	kfree(ms->gpio_cs);
 err_alloc:
 err_init:
	iounmap(regs);
	return rc;
}