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authorMaxime Ripard <maxime.ripard@bootlin.com>2019-05-20 16:50:33 +0200
committerMark Brown <broonie@kernel.org>2019-05-21 21:25:08 +0100
commit0a1b929356830257568f9547e173f0e7498060ea (patch)
tree3fabbb5e1f4bc79dd373ad46eed42f097ad2e634 /Documentation/devicetree/bindings/spi/spi-bus.txt
parent9783da2384c5623d376e4641bbce9339be1001eb (diff)
downloadlinux-0a1b929356830257568f9547e173f0e7498060ea.tar.gz
spi: Add YAML schemas for the generic SPI options
The SPI controllers have a bunch of generic options that are needed in a device tree. Add a YAML schemas for those. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'Documentation/devicetree/bindings/spi/spi-bus.txt')
-rw-r--r--Documentation/devicetree/bindings/spi/spi-bus.txt112
1 files changed, 1 insertions, 111 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index 1f6e86f787ef..e07783505498 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -1,111 +1 @@
-SPI (Serial Peripheral Interface) busses
-
-SPI busses can be described with a node for the SPI controller device
-and a set of child nodes for each SPI slave on the bus. The system's SPI
-controller may be described for use in SPI master mode or in SPI slave mode,
-but not for both at the same time.
-
-The SPI controller node requires the following properties:
-- compatible - Name of SPI bus controller following generic names
- recommended practice.
-
-In master mode, the SPI controller node requires the following additional
-properties:
-- #address-cells - number of cells required to define a chip select
- address on the SPI bus.
-- #size-cells - should be zero.
-
-In slave mode, the SPI controller node requires one additional property:
-- spi-slave - Empty property.
-
-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.
-
-Optional properties (master mode only):
-- cs-gpios - gpios chip select.
-- num-cs - total number of chipselects.
-
-If cs-gpios is used the number of chip selects will be increased automatically
-with max(cs-gpios > hw cs).
-
-So if for example the controller has 2 CS lines, and the cs-gpios
-property looks like this:
-
-cs-gpios = <&gpio1 0 0>, <0>, <&gpio1 1 0>, <&gpio1 2 0>;
-
-Then it should be configured so that num_chipselect = 4 with the
-following mapping:
-
-cs0 : &gpio1 0 0
-cs1 : native
-cs2 : &gpio1 1 0
-cs3 : &gpio1 2 0
-
-
-SPI slave nodes must be children of the SPI controller node.
-
-In master mode, one or more slave nodes (up to the number of chip selects) can
-be present. Required properties are:
-- compatible - Name of SPI device following generic names recommended
- practice.
-- reg - Chip select address of device.
-- spi-max-frequency - Maximum SPI clocking speed of device in Hz.
-
-In slave mode, the (single) slave node is optional.
-If present, it must be called "slave". Required properties are:
-- compatible - Name of SPI device following generic names recommended
- practice.
-
-All slave nodes can contain the following optional properties:
-- spi-cpol - Empty property indicating device requires inverse clock
- polarity (CPOL) mode.
-- spi-cpha - Empty property indicating device requires shifted clock
- phase (CPHA) mode.
-- spi-cs-high - Empty property indicating device requires chip select
- active high.
-- spi-3wire - Empty property indicating device requires 3-wire mode.
-- spi-lsb-first - Empty property indicating device requires LSB first mode.
-- spi-tx-bus-width - The bus width (number of data wires) that is used for MOSI.
- Defaults to 1 if not present.
-- spi-rx-bus-width - The bus width (number of data wires) that is used for MISO.
- Defaults to 1 if not present.
-- spi-rx-delay-us - Microsecond delay after a read transfer.
-- spi-tx-delay-us - Microsecond delay after a write transfer.
-
-Some SPI controllers and devices support Dual and Quad SPI transfer mode.
-It allows data in the SPI system to be transferred using 2 wires (DUAL) or 4
-wires (QUAD).
-Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is
-only 1 (SINGLE), 2 (DUAL) and 4 (QUAD).
-Dual/Quad mode is not allowed when 3-wire mode is used.
-
-If a gpio chipselect is used for the SPI slave the gpio number will be passed
-via the SPI master node cs-gpios property.
-
-SPI example for an MPC5200 SPI bus:
- spi@f00 {
- #address-cells = <1>;
- #size-cells = <0>;
- compatible = "fsl,mpc5200b-spi","fsl,mpc5200-spi";
- reg = <0xf00 0x20>;
- interrupts = <2 13 0 2 14 0>;
- interrupt-parent = <&mpc5200_pic>;
-
- ethernet-switch@0 {
- compatible = "micrel,ks8995m";
- spi-max-frequency = <1000000>;
- reg = <0>;
- };
-
- codec@1 {
- compatible = "ti,tlv320aic26";
- spi-max-frequency = <100000>;
- reg = <1>;
- };
- };
+This file has moved to spi-controller.yaml.