diff options
Diffstat (limited to 'Documentation')
7 files changed, 234 insertions, 152 deletions
diff --git a/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml b/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml index ff57c5416ebc..9f1d35ce1fe8 100644 --- a/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml +++ b/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml @@ -48,6 +48,9 @@ properties: default: 16 enum: [2, 4, 8, 16, 32, 64, 128, 256] + power-domains: + maxItems: 1 + required: - compatible - reg diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt deleted file mode 100644 index 548a73cde796..000000000000 --- a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt +++ /dev/null @@ -1,82 +0,0 @@ -GPIO-based I2C Arbitration Using a Challenge & Response Mechanism -================================================================= -This uses GPIO lines and a challenge & response mechanism to arbitrate who is -the master of an I2C bus in a multimaster situation. - -In many cases using GPIOs to arbitrate is not needed and a design can use -the standard I2C multi-master rules. Using GPIOs is generally useful in -the case where there is a device on the bus that has errata and/or bugs -that makes standard multimaster mode not feasible. - -Note that this scheme works well enough but has some downsides: -* It is nonstandard (not using standard I2C multimaster) -* Having two masters on a bus in general makes it relatively hard to debug - problems (hard to tell if i2c issues were caused by one master, another, or - some device on the bus). - - -Algorithm: - -All masters on the bus have a 'bus claim' line which is an output that the -others can see. These are all active low with pull-ups enabled. We'll -describe these lines as: - -- OUR_CLAIM: output from us signaling to other hosts that we want the bus -- THEIR_CLAIMS: output from others signaling that they want the bus - -The basic algorithm is to assert your line when you want the bus, then make -sure that the other side doesn't want it also. A detailed explanation is best -done with an example. - -Let's say we want to claim the bus. We: -1. Assert OUR_CLAIM. -2. Waits a little bit for the other sides to notice (slew time, say 10 - microseconds). -3. Check THEIR_CLAIMS. If none are asserted then the we have the bus and we are - done. -4. Otherwise, wait for a few milliseconds and see if THEIR_CLAIMS are released. -5. If not, back off, release the claim and wait for a few more milliseconds. -6. Go back to 1 (until retry time has expired). - - -Required properties: -- compatible: i2c-arb-gpio-challenge -- 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. -- 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. -- wait-retry-us: we'll attempt another claim after this many microseconds. - Default is 3000 us. -- wait-free-us: we'll give up after this many microseconds. Default is 50000 us. - - -Example: - i2c@12ca0000 { - compatible = "acme,some-i2c-device"; - #address-cells = <1>; - #size-cells = <0>; - }; - - i2c-arbitrator { - compatible = "i2c-arb-gpio-challenge"; - - i2c-parent = <&{/i2c@12CA0000}>; - - our-claim-gpio = <&gpf0 3 1>; - their-claim-gpios = <&gpe0 4 1>; - slew-delay-us = <10>; - wait-retry-us = <3000>; - wait-free-us = <50000>; - - i2c-arb { - #address-cells = <1>; - #size-cells = <0>; - - i2c@52 { - // Normal I2C device - }; - }; - }; diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.yaml b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.yaml new file mode 100644 index 000000000000..b618b5a3433a --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.yaml @@ -0,0 +1,135 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/i2c/i2c-arb-gpio-challenge.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: GPIO-based I2C Arbitration Using a Challenge & Response Mechanism + +maintainers: + - Doug Anderson <dianders@chromium.org> + - Peter Rosin <peda@axentia.se> + +description: | + This uses GPIO lines and a challenge & response mechanism to arbitrate who is + the master of an I2C bus in a multimaster situation. + + In many cases using GPIOs to arbitrate is not needed and a design can use the + standard I2C multi-master rules. Using GPIOs is generally useful in the case + where there is a device on the bus that has errata and/or bugs that makes + standard multimaster mode not feasible. + + Note that this scheme works well enough but has some downsides: + * It is nonstandard (not using standard I2C multimaster) + * Having two masters on a bus in general makes it relatively hard to debug + problems (hard to tell if i2c issues were caused by one master, another, + or some device on the bus). + + Algorithm: + All masters on the bus have a 'bus claim' line which is an output that the + others can see. These are all active low with pull-ups enabled. We'll + describe these lines as: + * OUR_CLAIM: output from us signaling to other hosts that we want the bus + * THEIR_CLAIMS: output from others signaling that they want the bus + + The basic algorithm is to assert your line when you want the bus, then make + sure that the other side doesn't want it also. A detailed explanation is + best done with an example. + + Let's say we want to claim the bus. We: + 1. Assert OUR_CLAIM. + 2. Waits a little bit for the other sides to notice (slew time, say 10 + microseconds). + 3. Check THEIR_CLAIMS. If none are asserted then the we have the bus and we + are done. + 4. Otherwise, wait for a few milliseconds and see if THEIR_CLAIMS are released. + 5. If not, back off, release the claim and wait for a few more milliseconds. + 6. Go back to 1 (until retry time has expired). + +properties: + compatible: + const: i2c-arb-gpio-challenge + + i2c-parent: + $ref: /schemas/types.yaml#/definitions/phandle + description: + The I2C bus that this multiplexer's master-side port is connected to. + + our-claim-gpios: + maxItems: 1 + description: + The GPIO that we use to claim the bus. + + slew-delay-us: + default: 10 + description: + Time to wait for a GPIO to go high. + + their-claim-gpios: + minItems: 1 + maxItems: 8 + description: + The GPIOs that the other sides use to claim the bus. Note that some + implementations may only support a single other master. + + wait-free-us: + default: 50000 + description: + We'll give up after this many microseconds. + + wait-retry-us: + default: 3000 + description: + We'll attempt another claim after this many microseconds. + + i2c-arb: + type: object + $ref: /schemas/i2c/i2c-controller.yaml + unevaluatedProperties: false + description: + I2C arbitration bus node. + +required: + - compatible + - i2c-arb + - our-claim-gpios + - their-claim-gpios + +additionalProperties: false + +examples: + - | + #include <dt-bindings/gpio/gpio.h> + #include <dt-bindings/interrupt-controller/irq.h> + + i2c-arbitrator { + compatible = "i2c-arb-gpio-challenge"; + i2c-parent = <&i2c_4>; + + our-claim-gpios = <&gpf0 3 GPIO_ACTIVE_LOW>; + their-claim-gpios = <&gpe0 4 GPIO_ACTIVE_LOW>; + slew-delay-us = <10>; + wait-retry-us = <3000>; + wait-free-us = <50000>; + + i2c-arb { + #address-cells = <1>; + #size-cells = <0>; + + sbs-battery@b { + compatible = "sbs,sbs-battery"; + reg = <0xb>; + sbs,poll-retry-count = <1>; + }; + + embedded-controller@1e { + compatible = "google,cros-ec-i2c"; + reg = <0x1e>; + interrupts = <6 IRQ_TYPE_LEVEL_HIGH>; + interrupt-parent = <&gpx1>; + pinctrl-names = "default"; + pinctrl-0 = <&ec_irq>; + wakeup-source; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb.txt b/Documentation/devicetree/bindings/i2c/i2c-arb.txt deleted file mode 100644 index 59abf9277bdc..000000000000 --- a/Documentation/devicetree/bindings/i2c/i2c-arb.txt +++ /dev/null @@ -1,35 +0,0 @@ -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-mux-pca954x.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml index 9f1726d0356b..2d7bb998b0e9 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml @@ -4,21 +4,29 @@ $id: http://devicetree.org/schemas/i2c/i2c-mux-pca954x.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# -title: NXP PCA954x I2C bus switch +title: NXP PCA954x I2C and compatible bus switches maintainers: - Laurent Pinchart <laurent.pinchart@ideasonboard.com> description: - The binding supports NXP PCA954x and PCA984x I2C mux/switch devices. - -allOf: - - $ref: /schemas/i2c/i2c-mux.yaml# + The NXP PCA954x and compatible devices are I2C bus + multiplexer/switches that share the same functionality + and register layout. + The devices usually have 4 or 8 child buses, which are + attached to the parent bus by using the SMBus "Send Byte" + command. properties: compatible: oneOf: - enum: + - maxim,max7356 + - maxim,max7357 + - maxim,max7358 + - maxim,max7367 + - maxim,max7368 + - maxim,max7369 - nxp,pca9540 - nxp,pca9542 - nxp,pca9543 @@ -59,10 +67,34 @@ properties: description: if present, overrides i2c-mux-idle-disconnect $ref: /schemas/mux/mux-controller.yaml#/properties/idle-state + vdd-supply: + description: A voltage regulator supplying power to the chip. On PCA9846 + the regulator supplies power to VDD2 (core logic) and optionally to VDD1. + required: - compatible - reg +allOf: + - $ref: /schemas/i2c/i2c-mux.yaml# + - if: + not: + properties: + compatible: + contains: + enum: + - maxim,max7367 + - maxim,max7369 + - nxp,pca9542 + - nxp,pca9543 + - nxp,pca9544 + - nxp,pca9545 + then: + properties: + interrupts: false + "#interrupt-cells": false + interrupt-controller: false + unevaluatedProperties: false examples: @@ -74,11 +106,13 @@ examples: #size-cells = <0>; i2c-mux@74 { - compatible = "nxp,pca9548"; + compatible = "nxp,pca9545"; #address-cells = <1>; #size-cells = <0>; reg = <0x74>; + vdd-supply = <&p3v3>; + interrupt-parent = <&ipic>; interrupts = <17 IRQ_TYPE_LEVEL_LOW>; interrupt-controller; diff --git a/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt b/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt deleted file mode 100644 index 42bfc09c8918..000000000000 --- a/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt +++ /dev/null @@ -1,29 +0,0 @@ -* NXP PCA9541 I2C bus master selector - -Required Properties: - - - compatible: Must be "nxp,pca9541" - - - reg: The I2C address of the device. - - The following required properties are defined externally: - - - I2C arbitration bus node. See i2c-arb.txt in this directory. - - -Example: - - i2c-arbitrator@74 { - compatible = "nxp,pca9541"; - reg = <0x74>; - - i2c-arb { - #address-cells = <1>; - #size-cells = <0>; - - eeprom@54 { - compatible = "atmel,24c08"; - reg = <0x54>; - }; - }; - }; diff --git a/Documentation/devicetree/bindings/i2c/nxp,pca9541.yaml b/Documentation/devicetree/bindings/i2c/nxp,pca9541.yaml new file mode 100644 index 000000000000..b65c25c1a435 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/nxp,pca9541.yaml @@ -0,0 +1,56 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/i2c/nxp,pca9541.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: NXP PCA9541 I2C bus master selector + +maintainers: + - Peter Rosin <peda@axentia.se> + +properties: + compatible: + const: nxp,pca9541 + + reg: + maxItems: 1 + + i2c-arb: + type: object + $ref: /schemas/i2c/i2c-controller.yaml + unevaluatedProperties: false + description: + I2C arbitration bus node. + +required: + - compatible + - reg + - i2c-arb + +additionalProperties: false + +examples: + - | + #include <dt-bindings/gpio/gpio.h> + #include <dt-bindings/interrupt-controller/irq.h> + + i2c { + #address-cells = <1>; + #size-cells = <0>; + + i2c-arbitrator@74 { + compatible = "nxp,pca9541"; + reg = <0x74>; + + i2c-arb { + #address-cells = <1>; + #size-cells = <0>; + + eeprom@54 { + compatible = "atmel,24c08"; + reg = <0x54>; + }; + }; + }; + }; |