1/*
2 * SPI OF support routines
3 * Copyright (C) 2008 Secret Lab Technologies Ltd.
4 *
5 * Support routines for deriving SPI device attachments from the device
6 * tree.
7 */
8
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/device.h>
12#include <linux/spi/spi.h>
13#include <linux/of_irq.h>
14#include <linux/of_spi.h>
15
16/**
17 * of_register_spi_devices - Register child devices onto the SPI bus
18 * @master:	Pointer to spi_master device
19 *
20 * Registers an spi_device for each child node of master node which has a 'reg'
21 * property.
22 */
23void of_register_spi_devices(struct spi_master *master)
24{
25	struct spi_device *spi;
26	struct device_node *nc;
27	const __be32 *prop;
28	int rc;
29	int len;
30
31	if (!master->dev.of_node)
32		return;
33
34	for_each_child_of_node(master->dev.of_node, nc) {
35		/* Alloc an spi_device */
36		spi = spi_alloc_device(master);
37		if (!spi) {
38			dev_err(&master->dev, "spi_device alloc error for %s\n",
39				nc->full_name);
40			spi_dev_put(spi);
41			continue;
42		}
43
44		/* Select device driver */
45		if (of_modalias_node(nc, spi->modalias,
46				     sizeof(spi->modalias)) < 0) {
47			dev_err(&master->dev, "cannot find modalias for %s\n",
48				nc->full_name);
49			spi_dev_put(spi);
50			continue;
51		}
52
53		/* Device address */
54		prop = of_get_property(nc, "reg", &len);
55		if (!prop || len < sizeof(*prop)) {
56			dev_err(&master->dev, "%s has no 'reg' property\n",
57				nc->full_name);
58			spi_dev_put(spi);
59			continue;
60		}
61		spi->chip_select = be32_to_cpup(prop);
62
63		/* Mode (clock phase/polarity/etc.) */
64		if (of_find_property(nc, "spi-cpha", NULL))
65			spi->mode |= SPI_CPHA;
66		if (of_find_property(nc, "spi-cpol", NULL))
67			spi->mode |= SPI_CPOL;
68		if (of_find_property(nc, "spi-cs-high", NULL))
69			spi->mode |= SPI_CS_HIGH;
70
71		/* Device speed */
72		prop = of_get_property(nc, "spi-max-frequency", &len);
73		if (!prop || len < sizeof(*prop)) {
74			dev_err(&master->dev, "%s has no 'spi-max-frequency' property\n",
75				nc->full_name);
76			spi_dev_put(spi);
77			continue;
78		}
79		spi->max_speed_hz = be32_to_cpup(prop);
80
81		/* IRQ */
82		spi->irq = irq_of_parse_and_map(nc, 0);
83
84		/* Store a pointer to the node in the device structure */
85		of_node_get(nc);
86		spi->dev.of_node = nc;
87
88		/* Register the new device */
89		request_module(spi->modalias);
90		rc = spi_add_device(spi);
91		if (rc) {
92			dev_err(&master->dev, "spi_device register error %s\n",
93				nc->full_name);
94			spi_dev_put(spi);
95		}
96
97	}
98}
99EXPORT_SYMBOL(of_register_spi_devices);
100