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284b0189 GL |
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); |