diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 14:12:21 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 14:12:21 -0700 |
commit | 87840a2b7e048018d18d60bdac5c09224de85370 (patch) | |
tree | 87e9f8a2317e39358f5ea189d79ef2158de5faf8 /Documentation/devicetree | |
parent | 2ab704a47e0f27df758840a589aec3298dbb98dd (diff) | |
parent | 662786a5429c3a992c6f884a647ee32424822358 (diff) |
Merge branch 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
"Here is the 4.9 pull request from I2C including:
- centralized error messages when registering to the core
- improved lockdep annotations to prevent false positives
- DT support for muxes, gates, and arbitrators
- bus speeds can now be obtained from ACPI
- i2c-octeon got refactored and now supports ThunderX SoCs, too
- i2c-tegra and i2c-designware got a bigger bunch of updates
- a couple of standard driver fixes and improvements"
* 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (71 commits)
i2c: axxia: disable clks in case of failure in probe
i2c: octeon: thunderx: Limit register access retries
i2c: uniphier-f: fix misdetection of incomplete STOP condition
gpio: pca953x: variable 'id' was used twice
i2c: i801: Add support for Kaby Lake PCH-H
gpio: pca953x: fix an incorrect lockdep warning
i2c: add a warning to i2c_adapter_depth()
lockdep: make MAX_LOCKDEP_SUBCLASSES unconditionally visible
i2c: export i2c_adapter_depth()
i2c: rk3x: Fix variable 'min_total_ns' unused warning
i2c: rk3x: Fix sparse warning
i2c / ACPI: Do not touch an I2C device if it belongs to another adapter
i2c: octeon: Fix high-level controller status check
i2c: octeon: Avoid sending STOP during recovery
i2c: octeon: Fix set SCL recovery function
i2c: rcar: add support for r8a7796 (R-Car M3-W)
i2c: imx: make bus recovery through pinctrl optional
i2c: meson: add gxbb compatible string
i2c: uniphier-f: set the adapter to master mode when probing
i2c: uniphier-f: avoid WARN_ON() of clk_disable() in failure path
...
Diffstat (limited to 'Documentation/devicetree')
7 files changed, 127 insertions, 12 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt index 71191ff0e781..248a155414c2 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt @@ -44,8 +44,7 @@ Required properties: - our-claim-gpio: The GPIO that we use to claim the bus. - their-claim-gpios: The GPIOs that the other sides use to claim the bus. Note that some implementations may only support a single other master. -- Standard I2C mux properties. See i2c-mux.txt in this directory. -- Single I2C child bus node at reg 0. See i2c-mux.txt in this directory. +- I2C arbitration bus node. See i2c-arb.txt in this directory. Optional properties: - slew-delay-us: microseconds to wait for a GPIO to go high. Default is 10 us. @@ -63,8 +62,6 @@ Example: i2c-arbitrator { compatible = "i2c-arb-gpio-challenge"; - #address-cells = <1>; - #size-cells = <0>; i2c-parent = <&{/i2c@12CA0000}>; @@ -74,8 +71,7 @@ Example: wait-retry-us = <3000>; wait-free-us = <50000>; - i2c@0 { - reg = <0>; + i2c-arb { #address-cells = <1>; #size-cells = <0>; diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb.txt b/Documentation/devicetree/bindings/i2c/i2c-arb.txt new file mode 100644 index 000000000000..59abf9277bdc --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-arb.txt @@ -0,0 +1,35 @@ +Common i2c arbitration bus properties. + +- i2c-arb child node + +Required properties for the i2c-arb child node: +- #address-cells = <1>; +- #size-cells = <0>; + +Optional properties for i2c-arb child node: +- Child nodes conforming to i2c bus binding + + +Example : + + /* + An NXP pca9541 I2C bus master selector at address 0x74 + with a NXP pca8574 GPIO expander attached. + */ + + arb@74 { + compatible = "nxp,pca9541"; + reg = <0x74>; + + i2c-arb { + #address-cells = <1>; + #size-cells = <0>; + + gpio@38 { + compatible = "nxp,pca8574"; + reg = <0x38>; + #gpio-cells = <2>; + gpio-controller; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/i2c/i2c-gate.txt b/Documentation/devicetree/bindings/i2c/i2c-gate.txt new file mode 100644 index 000000000000..1846d236e656 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-gate.txt @@ -0,0 +1,41 @@ +An i2c gate is useful to e.g. reduce the digital noise for RF tuners connected +to the i2c bus. Gates are similar to arbitrators in that you need to perform +some kind of operation to access the i2c bus past the arbitrator/gate, but +there are no competing masters to consider for gates and therefore there is +no arbitration happening for gates. + +Common i2c gate properties. + +- i2c-gate child node + +Required properties for the i2c-gate child node: +- #address-cells = <1>; +- #size-cells = <0>; + +Optional properties for i2c-gate child node: +- Child nodes conforming to i2c bus binding + + +Example : + + /* + An Invensense mpu9150 at address 0x68 featuring an on-chip Asahi + Kasei ak8975 compass behind a gate. + */ + + mpu9150@68 { + compatible = "invensense,mpu9150"; + reg = <0x68>; + interrupt-parent = <&gpio1>; + interrupts = <18 1>; + + i2c-gate { + #address-cells = <1>; + #size-cells = <0>; + + ax8975@c { + compatible = "ak,ak8975"; + reg = <0x0c>; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/i2c/i2c-meson.txt b/Documentation/devicetree/bindings/i2c/i2c-meson.txt index 682f9a6f766e..386357d1aab0 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-meson.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-meson.txt @@ -1,7 +1,7 @@ Amlogic Meson I2C controller Required properties: - - compatible: must be "amlogic,meson6-i2c" + - compatible: must be "amlogic,meson6-i2c" or "amlogic,meson-gxbb-i2c" - reg: physical address and length of the device registers - interrupts: a single interrupt specifier - clocks: clock for the device diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux.txt b/Documentation/devicetree/bindings/i2c/i2c-mux.txt index af84cce5cd7b..212e6779dc5c 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mux.txt @@ -2,19 +2,32 @@ Common i2c bus multiplexer/switch properties. An i2c bus multiplexer/switch will have several child busses that are numbered uniquely in a device dependent manner. The nodes for an i2c bus -multiplexer/switch will have one child node for each child -bus. +multiplexer/switch will have one child node for each child bus. -Required properties: +Optional properties: +- #address-cells = <1>; + This property is required is the i2c-mux child node does not exist. + +- #size-cells = <0>; + This property is required is the i2c-mux child node does not exist. + +- i2c-mux + For i2c multiplexers/switches that have child nodes that are a mixture + of both i2c child busses and other child nodes, the 'i2c-mux' subnode + can be used for populating the i2c child busses. If an 'i2c-mux' + subnode is present, only subnodes of this will be considered as i2c + child busses. + +Required properties for the i2c-mux child node: - #address-cells = <1>; - #size-cells = <0>; -Required properties for child nodes: +Required properties for i2c child bus nodes: - #address-cells = <1>; - #size-cells = <0>; - reg : The sub-bus number. -Optional properties for child nodes: +Optional properties for i2c child bus nodes: - Other properties specific to the multiplexer/switch hardware. - Child nodes conforming to i2c bus binding diff --git a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt index 5f0cb502b1db..239632a0d709 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt @@ -11,6 +11,7 @@ Required properties: "renesas,i2c-r8a7793" "renesas,i2c-r8a7794" "renesas,i2c-r8a7795" + "renesas,i2c-r8a7796" - reg: physical base address of the controller and length of memory mapped region. - interrupts: interrupt specifier. diff --git a/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt b/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt new file mode 100644 index 000000000000..0fbbc6970ec5 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt @@ -0,0 +1,29 @@ +* NXP PCA9541 I2C bus master selector + +Required Properties: + + - compatible: Must be "nxp,pca9541" + + - reg: The I2C address of the device. + + The following required properties are defined externally: + + - I2C arbitration bus node. See i2c-arb.txt in this directory. + + +Example: + + i2c-arbitrator@74 { + compatible = "nxp,pca9541"; + reg = <0x74>; + + i2c-arb { + #address-cells = <1>; + #size-cells = <0>; + + eeprom@54 { + compatible = "at,24c08"; + reg = <0x54>; + }; + }; + }; |