xref: /linux/Documentation/devicetree/bindings/spi/spi-davinci.txt (revision bd628c1bed7902ec1f24ba0fe70758949146abbe) 
1Davinci SPI controller device bindings
2
3Links on DM:
4Keystone 2 - http://www.ti.com/lit/ug/sprugp2a/sprugp2a.pdf
5dm644x - http://www.ti.com/lit/ug/sprue32a/sprue32a.pdf
6OMAP-L138/da830 - http://www.ti.com/lit/ug/spruh77a/spruh77a.pdf
7
8Required 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 specific SoC configuration.
25- interrupts: interrupt number mapped to CPU.
26- clocks: spi clk phandle
27          For 66AK2G this property should be set per binding,
28          Documentation/devicetree/bindings/clock/ti,sci-clk.txt
29
30SoC-specific Required Properties:
31
32The following are mandatory properties for Keystone 2 66AK2G SoCs only:
33
34- power-domains:	Should contain a phandle to a PM domain provider node
35			and an args specifier containing the SPI device id
36			value. This property is as per the binding,
37
38Optional:
39- cs-gpios: gpio chip selects
40	For example to have 3 internal CS and 2 GPIO CS, user could define
41	cs-gpios = <0>, <0>, <0>, <&gpio1 30 0>, <&gpio1 31 0>;
42	where first three are internal CS and last two are GPIO CS.
43
44Optional properties for slave devices:
45SPI slave nodes can contain the following properties.
46Not all SPI Peripherals from Texas Instruments support this.
47Please check SPI peripheral documentation for a device before using these.
48
49- ti,spi-wdelay : delay between transmission of words
50	(SPIFMTn.WDELAY, SPIDAT1.WDEL) must be specified in number of SPI module
51	clock periods.
52
53	delay = WDELAY * SPI_module_clock_period + 2 * SPI_module_clock_period
54
55Below is timing diagram which shows functional meaning of
56"ti,spi-wdelay" parameter.
57
58             +-+ +-+ +-+ +-+ +-+                           +-+ +-+ +-+
59SPI_CLK      | | | | | | | | | |                           | | | | | |
60  +----------+ +-+ +-+ +-+ +-+ +---------------------------+ +-+ +-+ +-
61
62SPI_SOMI/SIMO+-----------------+                           +-----------
63  +----------+ word1           +---------------------------+word2
64             +-----------------+                           +-----------
65                                          WDELAY
66                                <-------------------------->
67
68Example of a NOR flash slave device (n25q032) connected to DaVinci
69SPI controller device over the SPI bus.
70
71spi0:spi@20bf0000 {
72	#address-cells			= <1>;
73	#size-cells			= <0>;
74	compatible			= "ti,dm6446-spi";
75	reg				= <0x20BF0000 0x1000>;
76	num-cs				= <4>;
77	ti,davinci-spi-intr-line	= <0>;
78	interrupts			= <338>;
79	clocks				= <&clkspi>;
80
81	flash: n25q032@0 {
82		#address-cells = <1>;
83		#size-cells = <1>;
84		compatible = "st,m25p32";
85		spi-max-frequency = <25000000>;
86		reg = <0>;
87		ti,spi-wdelay = <8>;
88
89		partition@0 {
90			label = "u-boot-spl";
91			reg = <0x0 0x80000>;
92			read-only;
93		};
94
95		partition@1 {
96			label = "test";
97			reg = <0x80000 0x380000>;
98		};
99	};
100};
101