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authorGrant Likely <grant.likely@secretlab.ca>2008-05-16 13:37:09 -0400
committerGrant Likely <grant.likely@secretlab.ca>2008-07-25 22:34:40 -0400
commit284b01897340974000bcc84de87a4e1becc8a83d (patch)
tree9d2f38c9d2d39601d615f738c337c5af14a6b344 /drivers/of
parentdc87c98e8f635a718f1abb2c3e15fc77c0001651 (diff)
spi: Add OF binding support for SPI busses
This patch adds support for populating an SPI bus based on data in the OF device tree. This is useful for powerpc platforms which use the device tree instead of discrete code for describing platform layout. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/Kconfig6
-rw-r--r--drivers/of/Makefile1
-rw-r--r--drivers/of/of_spi.c93
3 files changed, 100 insertions, 0 deletions
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 1d7ec3129349..f821dbc952a4 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -13,3 +13,9 @@ config OF_I2C
13 depends on PPC_OF && I2C 13 depends on PPC_OF && I2C
14 help 14 help
15 OpenFirmware I2C accessors 15 OpenFirmware I2C accessors
16
17config OF_SPI
18 def_tristate SPI
19 depends on OF && PPC_OF && SPI
20 help
21 OpenFirmware SPI accessors
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 548772e871fd..4c3c6f8e36f5 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -2,3 +2,4 @@ obj-y = base.o
2obj-$(CONFIG_OF_DEVICE) += device.o platform.o 2obj-$(CONFIG_OF_DEVICE) += device.o platform.o
3obj-$(CONFIG_OF_GPIO) += gpio.o 3obj-$(CONFIG_OF_GPIO) += gpio.o
4obj-$(CONFIG_OF_I2C) += of_i2c.o 4obj-$(CONFIG_OF_I2C) += of_i2c.o
5obj-$(CONFIG_OF_SPI) += of_spi.o
diff --git a/drivers/of/of_spi.c b/drivers/of/of_spi.c
new file mode 100644
index 000000000000..b01eec026f68
--- /dev/null
+++ b/drivers/of/of_spi.c
@@ -0,0 +1,93 @@
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 */
22void 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}
93EXPORT_SYMBOL(of_register_spi_devices);