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-rw-r--r--Documentation/devicetree/bindings/spi/spi-davinci.txt30
1 files changed, 30 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-davinci.txt b/Documentation/devicetree/bindings/spi/spi-davinci.txt
index f80887bca0d6..12ecfe9e3599 100644
--- a/Documentation/devicetree/bindings/spi/spi-davinci.txt
+++ b/Documentation/devicetree/bindings/spi/spi-davinci.txt
@@ -1,5 +1,10 @@
Davinci SPI controller device bindings
+Links on DM:
+Keystone 2 - http://www.ti.com/lit/ug/sprugp2a/sprugp2a.pdf
+dm644x - http://www.ti.com/lit/ug/sprue32a/sprue32a.pdf
+OMAP-L138/da830 - http://www.ti.com/lit/ug/spruh77a/spruh77a.pdf
+
Required properties:
- #address-cells: number of cells required to define a chip select
address on the SPI bus. Should be set to 1.
@@ -24,6 +29,30 @@ Optional:
cs-gpios = <0>, <0>, <0>, <&gpio1 30 0>, <&gpio1 31 0>;
where first three are internal CS and last two are GPIO CS.
+Optional properties for slave devices:
+SPI slave nodes can contain the following properties.
+Not all SPI Peripherals from Texas Instruments support this.
+Please check SPI peripheral documentation for a device before using these.
+
+- ti,spi-wdelay : delay between transmission of words
+ (SPIFMTn.WDELAY, SPIDAT1.WDEL) must be specified in number of SPI module
+ clock periods.
+
+ delay = WDELAY * SPI_module_clock_period + 2 * SPI_module_clock_period
+
+Below is timing diagram which shows functional meaning of
+"ti,spi-wdelay" parameter.
+
+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+
+SPI_CLK | | | | | | | | | | | | | | | |
+ +----------+ +-+ +-+ +-+ +-+ +---------------------------+ +-+ +-+ +-
+
+SPI_SOMI/SIMO+-----------------+ +-----------
+ +----------+ word1 +---------------------------+word2
+ +-----------------+ +-----------
+ WDELAY
+ <-------------------------->
+
Example of a NOR flash slave device (n25q032) connected to DaVinci
SPI controller device over the SPI bus.
@@ -43,6 +72,7 @@ spi0:spi@20BF0000 {
compatible = "st,m25p32";
spi-max-frequency = <25000000>;
reg = <0>;
+ ti,spi-wdelay = <8>;
partition@0 {
label = "u-boot-spl";