> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > On Behalf Of Grant Likely > Sent: 2008?7?3? 9:03 > To: linuxppc-dev@ozlabs.org; > [EMAIL PROTECTED]; [EMAIL PROTECTED] > Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: [PATCH v2 3/5] of-bindings: Add binding > documentation for SPI bussesand devices > > From: Grant Likely <[EMAIL PROTECTED]> > > Add documentation about how to describe SPI busses in the device tree. > > Signed-off-by: Grant Likely <[EMAIL PROTECTED]> > --- > > Documentation/powerpc/booting-without-of.txt | 60 > ++++++++++++++++++++++++++ > 1 files changed, 60 insertions(+), 0 deletions(-) > > diff --git a/Documentation/powerpc/booting-without-of.txt > b/Documentation/powerpc/booting-without-of.txt > index 1d2a772..7d3564f 100644 > --- a/Documentation/powerpc/booting-without-of.txt > +++ b/Documentation/powerpc/booting-without-of.txt > @@ -58,6 +58,7 @@ Table of Contents > o) Xilinx IP cores > p) Freescale Synchronous Serial Interface > q) USB EHCI controllers > + t) SPI busses > > VII - Marvell Discovery mv64[345]6x System Controller chips > 1) The /system-controller node > @@ -2870,6 +2871,65 @@ platforms are moved over to use the > flattened-device-tree model. > reg = <0xe8000000 32>; > }; > > + t) 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 - (required) 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. > +
How about adding a "model" property to describe actual devie type. Such as using a "sst25vf040b" device with spi-interface, we can use model="sst25vf040b" to describe it. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
