of/gpio: Implement of_get_gpio_flags()
[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_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                 if (of_find_property(nc, "spi-cs-high", NULL))
65                         spi->mode |= SPI_CS_HIGH;
66
67                 /* Device speed */
68                 prop = of_get_property(nc, "spi-max-frequency", &len);
69                 if (!prop || len < sizeof(*prop)) {
70                         dev_err(&master->dev, "%s has no 'spi-max-frequency' property\n",
71                                 nc->full_name);
72                         spi_dev_put(spi);
73                         continue;
74                 }
75                 spi->max_speed_hz = *prop;
76
77                 /* IRQ */
78                 spi->irq = irq_of_parse_and_map(nc, 0);
79
80                 /* Store a pointer to the node in the device structure */
81                 of_node_get(nc);
82                 spi->dev.archdata.of_node = nc;
83
84                 /* Register the new device */
85                 request_module(spi->modalias);
86                 rc = spi_add_device(spi);
87                 if (rc) {
88                         dev_err(&master->dev, "spi_device register error %s\n",
89                                 nc->full_name);
90                         spi_dev_put(spi);
91                 }
92
93         }
94 }
95 EXPORT_SYMBOL(of_register_spi_devices);