Documentation/devicetree/bindings/spi/spi-davinci.txt

   1 Davinci SPI controller device bindings
   2
   3 Links on DM:
   4 Keystone 2 - http://www.ti.com/lit/ug/sprugp2a/sprugp2a.pdf
   5 dm644x - http://www.ti.com/lit/ug/sprue32a/sprue32a.pdf
   6 OMAP-L138/da830 - http://www.ti.com/lit/ug/spruh77a/spruh77a.pdf
   7
   8 Required properties:
   9 - #address-cells: number of cells required to define a chip select
  10         address on the SPI bus. Should be set to 1.
  11 - #size-cells: should be zero.
  12 - compatible:
  13         - "ti,dm6441-spi" for SPI used similar to that on DM644x SoC family
  14         - "ti,da830-spi" for SPI used similar to that on DA8xx SoC family
  15         - "ti,keystone-spi" for SPI used similar to that on Keystone2 SoC
  16                 family
  17 - reg: Offset and length of SPI controller register space
  18 - num-cs: Number of chip selects. This includes internal as well as
  19         GPIO chip selects.
  20 - ti,davinci-spi-intr-line: interrupt line used to connect the SPI
  21         IP to the interrupt controller within the SoC. Possible values
  22         are 0 and 1. Manual says one of the two possible interrupt
  23         lines can be tied to the interrupt controller. Set this
  24         based on a specifc SoC configuration.
  25 - interrupts: interrupt number mapped to CPU.
  26 - clocks: spi clk phandle
  27
  28 Optional:
  29 - cs-gpios: gpio chip selects
  30         For example to have 3 internal CS and 2 GPIO CS, user could define
  31         cs-gpios = <0>, <0>, <0>, <&gpio1 30 0>, <&gpio1 31 0>;
  32         where first three are internal CS and last two are GPIO CS.
  33
  34 Optional properties for slave devices:
  35 SPI slave nodes can contain the following properties.
  36 Not all SPI Peripherals from Texas Instruments support this.
  37 Please check SPI peripheral documentation for a device before using these.
  38
  39 - ti,spi-wdelay : delay between transmission of words
  40         (SPIFMTn.WDELAY, SPIDAT1.WDEL) must be specified in number of SPI module
  41         clock periods.
  42
  43         delay = WDELAY * SPI_module_clock_period + 2 * SPI_module_clock_period
  44
  45 Below is timing diagram which shows functional meaning of
  46 "ti,spi-wdelay" parameter.
  47
  48              +-+ +-+ +-+ +-+ +-+                           +-+ +-+ +-+
  49 SPI_CLK      | | | | | | | | | |                           | | | | | |
  50   +----------+ +-+ +-+ +-+ +-+ +---------------------------+ +-+ +-+ +-
  51
  52 SPI_SOMI/SIMO+-----------------+                           +-----------
  53   +----------+ word1           +---------------------------+word2
  54              +-----------------+                           +-----------
  55                                           WDELAY
  56                                 <-------------------------->
  57
  58 Example of a NOR flash slave device (n25q032) connected to DaVinci
  59 SPI controller device over the SPI bus.
  60
  61 spi0:spi@20BF0000 {
  62         #address-cells                  = <1>;
  63         #size-cells                     = <0>;
  64         compatible                      = "ti,dm6446-spi";
  65         reg                             = <0x20BF0000 0x1000>;
  66         num-cs                          = <4>;
  67         ti,davinci-spi-intr-line        = <0>;
  68         interrupts                      = <338>;
  69         clocks                          = <&clkspi>;
  70
  71         flash: n25q032@0 {
  72                 #address-cells = <1>;
  73                 #size-cells = <1>;
  74                 compatible = "st,m25p32";
  75                 spi-max-frequency = <25000000>;
  76                 reg = <0>;
  77                 ti,spi-wdelay = <8>;
  78
  79                 partition@0 {
  80                         label = "u-boot-spl";
  81                         reg = <0x0 0x80000>;
  82                         read-only;
  83                 };
  84
  85                 partition@1 {
  86                         label = "test";
  87                         reg = <0x80000 0x380000>;
  88                 };
  89         };
  90 };