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