/*
   * SPI OF support routines
   * Copyright (C) 2008 Secret Lab Technologies Ltd.
   *
   * Support routines for deriving SPI device attachments from the device
   * tree.
   */

  #include <linux/module.h>

  #include <linux/of.h>
  #include <linux/device.h>
  #include <linux/spi/spi.h>

  #include <linux/of_irq.h>

  #include <linux/of_spi.h>
  
  /**
   * of_register_spi_devices - Register child devices onto the SPI bus
   * @master:	Pointer to spi_master device

   *

   * Registers an spi_device for each child node of master node which has a 'reg'

   * property.
   */

  void of_register_spi_devices(struct spi_master *master)

  {
  	struct spi_device *spi;
  	struct device_node *nc;

  	const __be32 *prop;

  	int rc;
  	int len;

  	if (!master->dev.of_node)
  		return;
  
  	for_each_child_of_node(master->dev.of_node, nc) {

  		/* Alloc an spi_device */
  		spi = spi_alloc_device(master);
  		if (!spi) {
  			dev_err(&master->dev, "spi_device alloc error for %s
  ",
  				nc->full_name);
  			spi_dev_put(spi);
  			continue;
  		}
  
  		/* Select device driver */
  		if (of_modalias_node(nc, spi->modalias,
  				     sizeof(spi->modalias)) < 0) {
  			dev_err(&master->dev, "cannot find modalias for %s
  ",
  				nc->full_name);
  			spi_dev_put(spi);
  			continue;
  		}
  
  		/* Device address */
  		prop = of_get_property(nc, "reg", &len);
  		if (!prop || len < sizeof(*prop)) {
  			dev_err(&master->dev, "%s has no 'reg' property
  ",
  				nc->full_name);
  			spi_dev_put(spi);
  			continue;
  		}

  		spi->chip_select = be32_to_cpup(prop);

  
  		/* Mode (clock phase/polarity/etc.) */
  		if (of_find_property(nc, "spi-cpha", NULL))
  			spi->mode |= SPI_CPHA;
  		if (of_find_property(nc, "spi-cpol", NULL))
  			spi->mode |= SPI_CPOL;

  		if (of_find_property(nc, "spi-cs-high", NULL))
  			spi->mode |= SPI_CS_HIGH;

  
  		/* Device speed */
  		prop = of_get_property(nc, "spi-max-frequency", &len);
  		if (!prop || len < sizeof(*prop)) {
  			dev_err(&master->dev, "%s has no 'spi-max-frequency' property
  ",
  				nc->full_name);
  			spi_dev_put(spi);
  			continue;
  		}

  		spi->max_speed_hz = be32_to_cpup(prop);

  
  		/* IRQ */
  		spi->irq = irq_of_parse_and_map(nc, 0);
  
  		/* Store a pointer to the node in the device structure */
  		of_node_get(nc);

  		spi->dev.of_node = nc;

  
  		/* Register the new device */
  		request_module(spi->modalias);
  		rc = spi_add_device(spi);
  		if (rc) {
  			dev_err(&master->dev, "spi_device register error %s
  ",
  				nc->full_name);
  			spi_dev_put(spi);
  		}
  
  	}
  }
  EXPORT_SYMBOL(of_register_spi_devices);