I2C interface timing registers are configured using config setting
framework. Document available properties for Tegra I2C controllers.
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
.../bindings/i2c/nvidia,tegra20-i2c.yaml | 104 ++++++++++++++++++
1 file changed, 104 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
index 424a4fc218b6..3b22e75e5aa0 100644
--- a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
@@ -119,6 +119,96 @@ properties:
- const: rx
- const: tx
+ config:
+ description: Config settings for I2C devices enlisted with I2C controller.
+ Config setting is the configuration based on chip/board/system
+ characterization on interface/controller settings. This is needed for
+ - making the controller internal configuration to better perform
+ - making the interface to work proper by setting drive strength, slew
+ rates etc
+ - making the low power leakage.
+ There are two types of recommended configuration settings
+ - Controller register specific for internal operation of controller.
+ - Pad control/Pinmux/pincontrol registers for interfacing.
+ These configurations can further be categorized as static and dynamic.
+ - Static config does not change until a controller is reset.
+ - Dynamic config changes based on mode or condition, controller is
+ operating in.
+ I2C has configuration based on clock speed and has below modes.
+ - common is set on all speeds and can be overridden by speed mode.
+ - high is set when clock mode is high speed.
+ - fastplus is set when clock mode is fast plus.
+ - fast is set when clock mode is fast mode.
+ - standard is set when clock mode is standard mode.
+ $ref: /schemas/misc/nvidia,tegra-config-settings.yaml
+ unevaluatedProperties: false
+ properties:
+ nvidia,i2c-clk-divisor-hs-mode:
+ description: I2C clock divisor for HS mode.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-clk-divisor-fs-mode:
+ description: I2C clock divisor for FS mode.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-hs-sclk-high-period:
+ description: I2C high speed sclk high period.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-hs-sclk-low-period:
+ description: I2C high speed sclk low period.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-hs-stop-setup-time:
+ description: I2C high speed stop setup time.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-hs-start-hold-time:
+ description: I2C high speed start hold time.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-hs-start-setup-time:
+ description: I2C high speed start setup time.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-sclk-high-period:
+ description: I2C sclk high period.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-sclk-low-period:
+ description: I2C sclk low period.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-bus-free-time:
+ description: I2C bus free time.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-stop-setup-time:
+ description: I2C stop setup time.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-start-hold-time:
+ description: I2C start hold time.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+ nvidia,i2c-start-setup-time:
+ description: I2C start setup time.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 0xffff
+
allOf:
- $ref: /schemas/i2c/i2c-controller.yaml
- if:
@@ -189,4 +279,18 @@ examples:
#address-cells = <1>;
#size-cells = <0>;
+ config {
+ common {
+ nvidia,i2c-hs-sclk-high-period = <0x03>;
+ nvidia,i2c-hs-sclk-low-period = <0x08>;
+ };
+ fast {
+ nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+ nvidia,i2c-sclk-high-period = <0x02>;
+ };
+ fastplus {
+ nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+ nvidia,i2c-sclk-high-period = <0x07>;
+ };
+ };
};
--
2.43.2On Tue, 07 May 2024 04:21:32 +0530, Krishna Yarlagadda wrote: > I2C interface timing registers are configured using config setting > framework. Document available properties for Tegra I2C controllers. > > Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> > --- > .../bindings/i2c/nvidia,tegra20-i2c.yaml | 104 ++++++++++++++++++ > 1 file changed, 104 insertions(+) > My bot found errors running 'make dt_binding_check' on your patch: yamllint warnings/errors: dtschema/dtc warnings/errors: Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.example.dts:37.20-50.15: Warning (i2c_bus_reg): /example-0/i2c@7000c000/config: missing or empty reg property doc reference errors (make refcheckdocs): See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20240506225139.57647-5-kyarlagadda@nvidia.com The base for the series is generally the latest rc1. A different dependency should be noted in *this* patch. If you already ran 'make dt_binding_check' and didn't see the above error(s), then make sure 'yamllint' is installed and dt-schema is up to date: pip3 install dtschema --upgrade Please check and re-submit after running the above command yourself. Note that DT_SCHEMA_FILES can be set to your schema file to speed up checking your schema. However, it must be unset to test all examples with your schema.
On 07/05/2024 00:51, Krishna Yarlagadda wrote: > I2C interface timing registers are configured using config setting > framework. Document available properties for Tegra I2C controllers. > > Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> > --- > .../bindings/i2c/nvidia,tegra20-i2c.yaml | 104 ++++++++++++++++++ > 1 file changed, 104 insertions(+) > You called it RFC, so not ready for review, thus just few remarks. Please use subject prefixes matching the subsystem. You can get them for example with `git log --oneline -- DIRECTORY_OR_FILE` on the directory your patch is touching. For bindings, the preferred subjects are explained here: https://www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters > diff --git a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml > index 424a4fc218b6..3b22e75e5aa0 100644 > --- a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml > +++ b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml > @@ -119,6 +119,96 @@ properties: > - const: rx > - const: tx > > + config: > + description: Config settings for I2C devices enlisted with I2C controller. > + Config setting is the configuration based on chip/board/system > + characterization on interface/controller settings. This is needed for > + - making the controller internal configuration to better perform > + - making the interface to work proper by setting drive strength, slew > + rates etc > + - making the low power leakage. > + There are two types of recommended configuration settings > + - Controller register specific for internal operation of controller. > + - Pad control/Pinmux/pincontrol registers for interfacing. > + These configurations can further be categorized as static and dynamic. > + - Static config does not change until a controller is reset. > + - Dynamic config changes based on mode or condition, controller is > + operating in. > + I2C has configuration based on clock speed and has below modes. > + - common is set on all speeds and can be overridden by speed mode. > + - high is set when clock mode is high speed. > + - fastplus is set when clock mode is fast plus. > + - fast is set when clock mode is fast mode. > + - standard is set when clock mode is standard mode. > + $ref: /schemas/misc/nvidia,tegra-config-settings.yaml > + unevaluatedProperties: false > + properties: > + nvidia,i2c-clk-divisor-hs-mode: > + description: I2C clock divisor for HS mode. So you decided to implement clocks in DT? No. > + $ref: /schemas/types.yaml#/definitions/uint32 > + minimum: 0 > + maximum: 0xffff Anyway divisors, clock rates and everything is human-readable so in decimal, not hex. There are also several issues further, like using wrong units (time has a unit), but since this is RFC, I will just NAK. Best regards, Krzysztof
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