Commit | Line | Data |
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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 | ||
48a9e412 | 9 | #include <linux/module.h> |
284b0189 GL |
10 | #include <linux/of.h> |
11 | #include <linux/device.h> | |
12 | #include <linux/spi/spi.h> | |
e3873444 | 13 | #include <linux/of_irq.h> |
284b0189 GL |
14 | #include <linux/of_spi.h> |
15 | ||
16 | /** | |
17 | * of_register_spi_devices - Register child devices onto the SPI bus | |
18 | * @master: Pointer to spi_master device | |
284b0189 | 19 | * |
12b15e83 | 20 | * Registers an spi_device for each child node of master node which has a 'reg' |
284b0189 GL |
21 | * property. |
22 | */ | |
12b15e83 | 23 | void of_register_spi_devices(struct spi_master *master) |
284b0189 GL |
24 | { |
25 | struct spi_device *spi; | |
26 | struct device_node *nc; | |
33714881 | 27 | const __be32 *prop; |
284b0189 GL |
28 | int rc; |
29 | int len; | |
30 | ||
12b15e83 AG |
31 | if (!master->dev.of_node) |
32 | return; | |
33 | ||
34 | for_each_child_of_node(master->dev.of_node, nc) { | |
284b0189 GL |
35 | /* Alloc an spi_device */ |
36 | spi = spi_alloc_device(master); | |
37 | if (!spi) { | |
38 | dev_err(&master->dev, "spi_device alloc error for %s\n", | |
39 | nc->full_name); | |
40 | spi_dev_put(spi); | |
41 | continue; | |
42 | } | |
43 | ||
44 | /* Select device driver */ | |
45 | if (of_modalias_node(nc, spi->modalias, | |
46 | sizeof(spi->modalias)) < 0) { | |
47 | dev_err(&master->dev, "cannot find modalias for %s\n", | |
48 | nc->full_name); | |
49 | spi_dev_put(spi); | |
50 | continue; | |
51 | } | |
52 | ||
53 | /* Device address */ | |
54 | prop = of_get_property(nc, "reg", &len); | |
55 | if (!prop || len < sizeof(*prop)) { | |
56 | dev_err(&master->dev, "%s has no 'reg' property\n", | |
57 | nc->full_name); | |
58 | spi_dev_put(spi); | |
59 | continue; | |
60 | } | |
33714881 | 61 | spi->chip_select = be32_to_cpup(prop); |
284b0189 GL |
62 | |
63 | /* Mode (clock phase/polarity/etc.) */ | |
64 | if (of_find_property(nc, "spi-cpha", NULL)) | |
65 | spi->mode |= SPI_CPHA; | |
66 | if (of_find_property(nc, "spi-cpol", NULL)) | |
67 | spi->mode |= SPI_CPOL; | |
f618ebfc WO |
68 | if (of_find_property(nc, "spi-cs-high", NULL)) |
69 | spi->mode |= SPI_CS_HIGH; | |
284b0189 GL |
70 | |
71 | /* Device speed */ | |
72 | prop = of_get_property(nc, "spi-max-frequency", &len); | |
73 | if (!prop || len < sizeof(*prop)) { | |
74 | dev_err(&master->dev, "%s has no 'spi-max-frequency' property\n", | |
75 | nc->full_name); | |
76 | spi_dev_put(spi); | |
77 | continue; | |
78 | } | |
33714881 | 79 | spi->max_speed_hz = be32_to_cpup(prop); |
284b0189 GL |
80 | |
81 | /* IRQ */ | |
82 | spi->irq = irq_of_parse_and_map(nc, 0); | |
83 | ||
84 | /* Store a pointer to the node in the device structure */ | |
85 | of_node_get(nc); | |
d706c1b0 | 86 | spi->dev.of_node = nc; |
284b0189 GL |
87 | |
88 | /* Register the new device */ | |
89 | request_module(spi->modalias); | |
90 | rc = spi_add_device(spi); | |
91 | if (rc) { | |
92 | dev_err(&master->dev, "spi_device register error %s\n", | |
93 | nc->full_name); | |
94 | spi_dev_put(spi); | |
95 | } | |
96 | ||
97 | } | |
98 | } | |
99 | EXPORT_SYMBOL(of_register_spi_devices); |