aboutsummaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/spi/spi-bus.txt
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2011-02-19 19:17:35 -0800
committerDavid S. Miller <davem@davemloft.net>2011-02-19 19:17:35 -0800
commitda935c66bacb3ed9ada984b053297f87c2dff63a (patch)
tree46278da2b312c73f1375b830d7e5912bf23abd78 /Documentation/devicetree/bindings/spi/spi-bus.txt
parent9435eb1cf0b76b323019cebf8d16762a50a12a19 (diff)
parent2205a6ea93fea76f88b43727fea53f3ce3790d6f (diff)
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts: Documentation/feature-removal-schedule.txt drivers/net/e1000e/netdev.c net/xfrm/xfrm_policy.c
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 00000000000..e782add2e45
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -0,0 +1,57 @@
+SPI (Serial Peripheral Interface) busses
+
+SPI busses can be described with a node for the SPI master device
+and a set of child nodes for each SPI slave on the bus. For this
+discussion, it is assumed that the system's SPI controller is in
+SPI master mode. This binding does not describe SPI controllers
+in slave mode.
+
+The SPI master node requires the following properties:
+- #address-cells - number of cells required to define a chip select
+ address on the SPI bus.
+- #size-cells - should be zero.
+- compatible - name of SPI bus controller following generic names
+ recommended practice.
+No other properties are required in the SPI bus node. It is assumed
+that a driver for an SPI bus device will understand that it is an SPI bus.
+However, the binding does not attempt to define the specific method for
+assigning chip select numbers. Since SPI chip select configuration is
+flexible and non-standardized, it is left out of this binding with the
+assumption that board specific platform code will be used to manage
+chip selects. Individual drivers can define additional properties to
+support describing the chip select layout.
+
+SPI slave nodes must be children of the SPI master node and can
+contain the following properties.
+- reg - (required) chip select address of device.
+- compatible - (required) name of SPI device following generic names
+ recommended practice
+- spi-max-frequency - (required) Maximum SPI clocking speed of device in Hz
+- spi-cpol - (optional) Empty property indicating device requires
+ inverse clock polarity (CPOL) mode
+- spi-cpha - (optional) Empty property indicating device requires
+ shifted clock phase (CPHA) mode
+- spi-cs-high - (optional) Empty property indicating device requires
+ chip select active high
+
+SPI example for an MPC5200 SPI bus:
+ spi@f00 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "fsl,mpc5200b-spi","fsl,mpc5200-spi";
+ reg = <0xf00 0x20>;
+ interrupts = <2 13 0 2 14 0>;
+ interrupt-parent = <&mpc5200_pic>;
+
+ ethernet-switch@0 {
+ compatible = "micrel,ks8995m";
+ spi-max-frequency = <1000000>;
+ reg = <0>;
+ };
+
+ codec@1 {
+ compatible = "ti,tlv320aic26";
+ spi-max-frequency = <100000>;
+ reg = <1>;
+ };
+ };