Message ID | 20230619153732.46258-2-clamor95@gmail.com |
---|---|
State | Superseded |
Headers | show |
Series | GPIO-based hotplug i2c bus | expand |
On 19/06/2023 17:37, Svyatoslav Ryhel wrote: > Document device tree schema which describes hot-pluggable via GPIO > i2c bus. > > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com> 1. Don't send new version before discussion finishes. v2 after one hour is definitely not enough. Usually one day. 2. Test the patches before sending... What changed here? > --- > .../bindings/i2c/i2c-hotplug-gpio.yaml | 65 +++++++++++++++++++ > 1 file changed, 65 insertions(+) > create mode 100644 Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml b/Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml > new file mode 100644 > index 000000000000..21f2b74ca6c1 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml > @@ -0,0 +1,65 @@ > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/i2c/i2c-hotplug-gpio.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: GPIO detected hot-plugged I2C bus > + > +maintainers: > + - Michał Mirosław <mirq-linux@rere.qmqm.pl> > + > +description: > + Driver for hot-plugged I2C busses, where some devices on a bus "Driver" so SW? Bindings are for hardware, not for drivers. > + are hot-pluggable and their presence is indicated by GPIO line. > + > +properties: > + compatible: > + items: Drop items. > + - const: i2c-hotplug-gpio > + > + '#address-cells': > + const: 1 > + > + '#size-cells': > + const: 0 > + > + interrupts-extended: I missed last time - this is wrong. Just interrupts. > + minItems: 1 maxItems > + > + detect-gpios: > + maxItems: 1 > + > + i2c-parent: > + maxItems: 1 Discussion from v1 stands - this is a software construct, not a real device. > + > +required: > + - compatible > + - '#address-cells' > + - '#size-cells' > + - interrupts-extended > + - detect-gpios > + - i2c-parent > + > +unevaluatedProperties: false instead additionalProperties: false Anyway, don't send v3, before the discussion about the entire concept finishes. You create a software/virtual device, instead of adding these properties to bindings for a real hardware. > + > +examples: > + - | > + /* > + * Asus Transformers use I2C hotplug for attachable dock keyboard > + */ > + #include <dt-bindings/gpio/gpio.h> > + #include <dt-bindings/interrupt-controller/irq.h> > + > + i2c-dock { > + compatible = "i2c-hotplug-gpio"; > + > + #address-cells = <1>; > + #size-cells = <0>; > + > + interrupts-extended = <&gpio 164 IRQ_TYPE_EDGE_BOTH>; > + detect-gpios = <&gpio 164 GPIO_ACTIVE_LOW>; I don't think you can have both interrupt and GPIO on the same line. > + > + i2c-parent = <&gen2_i2c>; > + }; > +... Best regards, Krzysztof
On Mon, Jun 19, 2023 at 05:53:24PM +0200, Krzysztof Kozlowski wrote: > On 19/06/2023 17:37, Svyatoslav Ryhel wrote: > > Document device tree schema which describes hot-pluggable via GPIO > > i2c bus. > > > > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com> [...] > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml > > @@ -0,0 +1,65 @@ > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/i2c/i2c-hotplug-gpio.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: GPIO detected hot-plugged I2C bus > > + > > +maintainers: > > + - Michał Mirosław <mirq-linux@rere.qmqm.pl> > > + > > +description: > > + Driver for hot-plugged I2C busses, where some devices on a bus > > "Driver" so SW? Bindings are for hardware, not for drivers. [...] > > + detect-gpios: > > + maxItems: 1 > > + > > + i2c-parent: > > + maxItems: 1 > > Discussion from v1 stands - this is a software construct, not a real device. [...] > Anyway, don't send v3, before the discussion about the entire concept > finishes. You create a software/virtual device, instead of adding these > properties to bindings for a real hardware. Hi, In this case it's hard for me to tell the difference if this is real or virtual hardware. The Transformers have a connector that's used for USB, charging or for attaching a keyboard (called a dock; it also has a battery and a touchpad). This connector probably (I don't have the means to verify that) has an I2C bus lines and a "detect" line (pulled low on the dock side) among the pins. I guess there is either no additional chip or a transparent bridge/buffer chip, but nothing that could be controlled by software. For DT this setup could be modelled like an I2C gate or 2-port mux with enable joining two I2C busses (one "closer" to the CPU -- parent). > > + > > +examples: > > + - | > > + /* > > + * Asus Transformers use I2C hotplug for attachable dock keyboard > > + */ > > + #include <dt-bindings/gpio/gpio.h> > > + #include <dt-bindings/interrupt-controller/irq.h> > > + > > + i2c-dock { > > + compatible = "i2c-hotplug-gpio"; > > + > > + #address-cells = <1>; > > + #size-cells = <0>; > > + > > + interrupts-extended = <&gpio 164 IRQ_TYPE_EDGE_BOTH>; > > + detect-gpios = <&gpio 164 GPIO_ACTIVE_LOW>; > > I don't think you can have both interrupt and GPIO on the same line. This actually works as expected. There are multiple devices (and drivers) that depend on this, e.g. matrix-keypad and gpio-keys. Best Regards Michał Mirosław
diff --git a/Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml b/Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml new file mode 100644 index 000000000000..21f2b74ca6c1 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml @@ -0,0 +1,65 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/i2c/i2c-hotplug-gpio.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: GPIO detected hot-plugged I2C bus + +maintainers: + - Michał Mirosław <mirq-linux@rere.qmqm.pl> + +description: + Driver for hot-plugged I2C busses, where some devices on a bus + are hot-pluggable and their presence is indicated by GPIO line. + +properties: + compatible: + items: + - const: i2c-hotplug-gpio + + '#address-cells': + const: 1 + + '#size-cells': + const: 0 + + interrupts-extended: + minItems: 1 + + detect-gpios: + maxItems: 1 + + i2c-parent: + maxItems: 1 + +required: + - compatible + - '#address-cells' + - '#size-cells' + - interrupts-extended + - detect-gpios + - i2c-parent + +unevaluatedProperties: false + +examples: + - | + /* + * Asus Transformers use I2C hotplug for attachable dock keyboard + */ + #include <dt-bindings/gpio/gpio.h> + #include <dt-bindings/interrupt-controller/irq.h> + + i2c-dock { + compatible = "i2c-hotplug-gpio"; + + #address-cells = <1>; + #size-cells = <0>; + + interrupts-extended = <&gpio 164 IRQ_TYPE_EDGE_BOTH>; + detect-gpios = <&gpio 164 GPIO_ACTIVE_LOW>; + + i2c-parent = <&gen2_i2c>; + }; +...
Document device tree schema which describes hot-pluggable via GPIO i2c bus. Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com> --- .../bindings/i2c/i2c-hotplug-gpio.yaml | 65 +++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-hotplug-gpio.yaml