diff options
author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
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committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
commit | fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch) | |
tree | a57612d1888735a2ec7972891b68c1ac5ec8faea /drivers/of/of_spi.c | |
parent | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff) |
Diffstat (limited to 'drivers/of/of_spi.c')
-rw-r--r-- | drivers/of/of_spi.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/drivers/of/of_spi.c b/drivers/of/of_spi.c new file mode 100644 index 00000000000..1dbce58a58b --- /dev/null +++ b/drivers/of/of_spi.c | |||
@@ -0,0 +1,98 @@ | |||
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); | ||