mirror of
https://github.com/torvalds/linux.git
synced 2024-12-18 00:53:40 +00:00
fa466c9197
Currently the pre-scaler limit is incorrect. The value differs slightly for various devices so a single value can't be used. Using the compatible field select the correct pre-scaler limit. Add new compatible field value for Keystone devices to support their unique pre-scaler limit value. Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com> Reviewed-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Mark Brown <broonie@kernel.org>
91 lines
3.0 KiB
Plaintext
91 lines
3.0 KiB
Plaintext
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.
|
|
- #size-cells: should be zero.
|
|
- compatible:
|
|
- "ti,dm6441-spi" for SPI used similar to that on DM644x SoC family
|
|
- "ti,da830-spi" for SPI used similar to that on DA8xx SoC family
|
|
- "ti,keystone-spi" for SPI used similar to that on Keystone2 SoC
|
|
family
|
|
- reg: Offset and length of SPI controller register space
|
|
- num-cs: Number of chip selects. This includes internal as well as
|
|
GPIO chip selects.
|
|
- ti,davinci-spi-intr-line: interrupt line used to connect the SPI
|
|
IP to the interrupt controller within the SoC. Possible values
|
|
are 0 and 1. Manual says one of the two possible interrupt
|
|
lines can be tied to the interrupt controller. Set this
|
|
based on a specifc SoC configuration.
|
|
- interrupts: interrupt number mapped to CPU.
|
|
- clocks: spi clk phandle
|
|
|
|
Optional:
|
|
- cs-gpios: gpio chip selects
|
|
For example to have 3 internal CS and 2 GPIO CS, user could define
|
|
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.
|
|
|
|
spi0:spi@20BF0000 {
|
|
#address-cells = <1>;
|
|
#size-cells = <0>;
|
|
compatible = "ti,dm6446-spi";
|
|
reg = <0x20BF0000 0x1000>;
|
|
num-cs = <4>;
|
|
ti,davinci-spi-intr-line = <0>;
|
|
interrupts = <338>;
|
|
clocks = <&clkspi>;
|
|
|
|
flash: n25q032@0 {
|
|
#address-cells = <1>;
|
|
#size-cells = <1>;
|
|
compatible = "st,m25p32";
|
|
spi-max-frequency = <25000000>;
|
|
reg = <0>;
|
|
ti,spi-wdelay = <8>;
|
|
|
|
partition@0 {
|
|
label = "u-boot-spl";
|
|
reg = <0x0 0x80000>;
|
|
read-only;
|
|
};
|
|
|
|
partition@1 {
|
|
label = "test";
|
|
reg = <0x80000 0x380000>;
|
|
};
|
|
};
|
|
};
|