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/*
* SPI OF support routines
* Copyright (C) 2008 Secret Lab Technologies Ltd.
*
* Support routines for deriving SPI device attachments from the device
* tree.
*/
#include <linux/of.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/of_spi.h>
/**
* of_register_spi_devices - Register child devices onto the SPI bus
* @master: Pointer to spi_master device
* @np: parent node of SPI device nodes
*
* Registers an spi_device for each child node of 'np' which has a 'reg'
* property.
*/
void of_register_spi_devices(struct spi_master *master, struct device_node *np)
{
struct spi_device *spi;
struct device_node *nc;
const __be32 *prop;
int rc;
int len;
for_each_child_of_node(np, nc) {
/* Alloc an spi_device */
spi = spi_alloc_device(master);
if (!spi) {
dev_err(&master->dev, "spi_device alloc error for %s\n",
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\n",
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\n",
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\n",
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;
spi->dev.archdata.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\n",
nc->full_name);
spi_dev_put(spi);
}
}
}
EXPORT_SYMBOL(of_register_spi_devices);
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