of/promtree: no longer call prom_ functions directly; use an ops structure
[linux-2.6.git] / 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_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  */
22 void 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 }
98 EXPORT_SYMBOL(of_register_spi_devices);