Merge branch 'x86/spinlocks' into x86/xen
[linux-2.6] / drivers / of / of_spi.c
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_spi.h>
13
14 /**
15  * of_register_spi_devices - Register child devices onto the SPI bus
16  * @master:     Pointer to spi_master device
17  * @np:         parent node of SPI device nodes
18  *
19  * Registers an spi_device for each child node of 'np' which has a 'reg'
20  * property.
21  */
22 void of_register_spi_devices(struct spi_master *master, struct device_node *np)
23 {
24         struct spi_device *spi;
25         struct device_node *nc;
26         const u32 *prop;
27         int rc;
28         int len;
29
30         for_each_child_of_node(np, nc) {
31                 /* Alloc an spi_device */
32                 spi = spi_alloc_device(master);
33                 if (!spi) {
34                         dev_err(&master->dev, "spi_device alloc error for %s\n",
35                                 nc->full_name);
36                         spi_dev_put(spi);
37                         continue;
38                 }
39
40                 /* Select device driver */
41                 if (of_modalias_node(nc, spi->modalias,
42                                      sizeof(spi->modalias)) < 0) {
43                         dev_err(&master->dev, "cannot find modalias for %s\n",
44                                 nc->full_name);
45                         spi_dev_put(spi);
46                         continue;
47                 }
48
49                 /* Device address */
50                 prop = of_get_property(nc, "reg", &len);
51                 if (!prop || len < sizeof(*prop)) {
52                         dev_err(&master->dev, "%s has no 'reg' property\n",
53                                 nc->full_name);
54                         spi_dev_put(spi);
55                         continue;
56                 }
57                 spi->chip_select = *prop;
58
59                 /* Mode (clock phase/polarity/etc.) */
60                 if (of_find_property(nc, "spi-cpha", NULL))
61                         spi->mode |= SPI_CPHA;
62                 if (of_find_property(nc, "spi-cpol", NULL))
63                         spi->mode |= SPI_CPOL;
64
65                 /* Device speed */
66                 prop = of_get_property(nc, "spi-max-frequency", &len);
67                 if (!prop || len < sizeof(*prop)) {
68                         dev_err(&master->dev, "%s has no 'spi-max-frequency' property\n",
69                                 nc->full_name);
70                         spi_dev_put(spi);
71                         continue;
72                 }
73                 spi->max_speed_hz = *prop;
74
75                 /* IRQ */
76                 spi->irq = irq_of_parse_and_map(nc, 0);
77
78                 /* Store a pointer to the node in the device structure */
79                 of_node_get(nc);
80                 spi->dev.archdata.of_node = nc;
81
82                 /* Register the new device */
83                 request_module(spi->modalias);
84                 rc = spi_add_device(spi);
85                 if (rc) {
86                         dev_err(&master->dev, "spi_device register error %s\n",
87                                 nc->full_name);
88                         spi_dev_put(spi);
89                 }
90
91         }
92 }
93 EXPORT_SYMBOL(of_register_spi_devices);