aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/devicetree/bindings/spi/spi-bus.txt
diff options
context:
space:
mode:
authorGreg Kroah-Hartman <gregkh@suse.de>2011-02-24 14:36:31 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2011-02-24 14:36:31 -0500
commitf227e08b71b9c273eaa29a57370a3a5b833aa382 (patch)
tree9f1483776a2bde3bb1a6bd744e69acf19f6f3428 /Documentation/devicetree/bindings/spi/spi-bus.txt
parentfec38d1752c01ad72789bac9f1a128f7e933735d (diff)
parentf5412be599602124d2bdd49947b231dd77c0bf99 (diff)
Merge 2.6.38-rc6 into tty-next
This was to resolve a merge issue with drivers/char/Makefile and drivers/tty/serial/68328serial.c Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/devicetree/bindings/spi/spi-bus.txt')
-rw-r--r--Documentation/devicetree/bindings/spi/spi-bus.txt57
1 files changed, 57 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
new file mode 100644
index 000000000000..e782add2e457
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -0,0 +1,57 @@
1SPI (Serial Peripheral Interface) busses
2
3SPI busses can be described with a node for the SPI master device
4and a set of child nodes for each SPI slave on the bus. For this
5discussion, it is assumed that the system's SPI controller is in
6SPI master mode. This binding does not describe SPI controllers
7in slave mode.
8
9The SPI master node requires the following properties:
10- #address-cells - number of cells required to define a chip select
11 address on the SPI bus.
12- #size-cells - should be zero.
13- compatible - name of SPI bus controller following generic names
14 recommended practice.
15No other properties are required in the SPI bus node. It is assumed
16that a driver for an SPI bus device will understand that it is an SPI bus.
17However, the binding does not attempt to define the specific method for
18assigning chip select numbers. Since SPI chip select configuration is
19flexible and non-standardized, it is left out of this binding with the
20assumption that board specific platform code will be used to manage
21chip selects. Individual drivers can define additional properties to
22support describing the chip select layout.
23
24SPI slave nodes must be children of the SPI master node and can
25contain the following properties.
26- reg - (required) chip select address of device.
27- compatible - (required) name of SPI device following generic names
28 recommended practice
29- spi-max-frequency - (required) Maximum SPI clocking speed of device in Hz
30- spi-cpol - (optional) Empty property indicating device requires
31 inverse clock polarity (CPOL) mode
32- spi-cpha - (optional) Empty property indicating device requires
33 shifted clock phase (CPHA) mode
34- spi-cs-high - (optional) Empty property indicating device requires
35 chip select active high
36
37SPI example for an MPC5200 SPI bus:
38 spi@f00 {
39 #address-cells = <1>;
40 #size-cells = <0>;
41 compatible = "fsl,mpc5200b-spi","fsl,mpc5200-spi";
42 reg = <0xf00 0x20>;
43 interrupts = <2 13 0 2 14 0>;
44 interrupt-parent = <&mpc5200_pic>;
45
46 ethernet-switch@0 {
47 compatible = "micrel,ks8995m";
48 spi-max-frequency = <1000000>;
49 reg = <0>;
50 };
51
52 codec@1 {
53 compatible = "ti,tlv320aic26";
54 spi-max-frequency = <100000>;
55 reg = <1>;
56 };
57 };