Messages in this thread | | | Date | Fri, 16 May 2008 13:47:20 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH 3/4] spi: Add OF binding support for SPI busses |
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On Fri, 16 May 2008 13:36:13 -0600 Grant Likely wrote:
> diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt > index 1d2a772..452c242 100644 > --- a/Documentation/powerpc/booting-without-of.txt > +++ b/Documentation/powerpc/booting-without-of.txt > @@ -2870,6 +2871,66 @@ platforms are moved over to use the flattened-device-tree model. > reg = <0xe8000000 32>; > }; > > + s) 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 > + - max-speed - (optional) Maximum SPI clocking speed of device in Hz > + - spi,cpol - (optional) Device requires inverse clock polarity > + - spi,cpha - (optional) Device requires shifted clock phase > + - linux,modalias - (optional, Linux specific) Force binding of SPI device > + to a particular spi_device driver. Useful for changing > + driver binding between spidev and a kernel spi driver. ~~~
Hi, You mostly capitalize "SPI" in sentences (i.e., when it's not part of a function name or OF data), so could the 3 underlined instances of it also be all caps?
Thanks, --- ~Randy
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