| Message ID | 1439066007-13951-11-git-send-email-wsa@the-dreams.de (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
On Sunday 09 August 2015 02:03 AM, Wolfram Sang wrote: > From: Wolfram Sang <wsa+renesas@sang-engineering.com> > > Start a new file which describes the generic bindings used for I2C with > device tree. So we have a central place to look for them, increase > visibility of them, and hopefully reduce the amount of custom properties > introduced. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > --- > Documentation/devicetree/bindings/i2c/i2c.txt | 33 +++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > create mode 100644 Documentation/devicetree/bindings/i2c/i2c.txt > > diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt > new file mode 100644 > index 00000000000000..1175efed4a41b5 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/i2c.txt > @@ -0,0 +1,33 @@ > +Generic device tree bindings for I2C busses > +=========================================== > + > +This document describes generic bindings which can be used to describe I2C > +busses in a device tree. > + > +Required properties > +------------------- > + > +- #address-cells - should be <1>. Read more about addresses below. > +- #size-cells - should be <0>. > +- compatible - name of I2C bus controller following generic names > + recommended practice. > + > +For other required properties e.g. to describe register sets, interrupts, > +clocks, etc. check the binding documentation of the specific driver. > + > +The cells properties above define that an address of children of an I2C bus > +are described by a single value. This is usually a 7 bit address. However, > +flags can be attached to the address. I2C_TEN_BIT_ADDRESS is used to mark a 10 > +bit address. It is needed to avoid the ambiguity between e.g. a 7 bit address > +of 0x50 and a 10 bit address of 0x050 which, in theory, can be on the same bus. > +Another flag is I2C_OWN_SLAVE_ADDRESS to mark addresses on which we listen to > +be devices ourselves. > + > +Optional properties > +------------------- > + > +These properties may not be supported by all drivers. However, if a driver > +wants to support one of the below features, it should adapt the bindings below. > + > +- clock-frequency - frequency of bus clock in Hz > +- wakeup-source - device can be used as a wakeup source. > Thanks for the patch and it looks good to me. Shouldn't we also update/add other generic optional properties? For example, - i2c-sclk-low-time-ns - i2c-sclk-high-time-ns - etc... We need to consolidate all such generic properties in here. Thanks, Vaibhav -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> Thanks for the patch and it looks good to me. Thanks, I interpret this as an Acked-by :) > Shouldn't we also update/add other generic optional properties? > For example, > > - i2c-sclk-low-time-ns > - i2c-sclk-high-time-ns > - etc... Yes, I will do this as an incremental patch once people are happy with this start. Review is usually easier if done in small chunks.
On Sunday 09 August 2015 05:45 PM, Wolfram Sang wrote: > >> Thanks for the patch and it looks good to me. > > Thanks, I interpret this as an Acked-by :) > >> Shouldn't we also update/add other generic optional properties? >> For example, >> >> - i2c-sclk-low-time-ns >> - i2c-sclk-high-time-ns >> - etc... > > Yes, I will do this as an incremental patch once people are happy with > this start. Review is usually easier if done in small chunks. > Agreed. Feel free to add Reviewed-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org> Thanks, Vaibhav -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt new file mode 100644 index 00000000000000..1175efed4a41b5 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c.txt @@ -0,0 +1,33 @@ +Generic device tree bindings for I2C busses +=========================================== + +This document describes generic bindings which can be used to describe I2C +busses in a device tree. + +Required properties +------------------- + +- #address-cells - should be <1>. Read more about addresses below. +- #size-cells - should be <0>. +- compatible - name of I2C bus controller following generic names + recommended practice. + +For other required properties e.g. to describe register sets, interrupts, +clocks, etc. check the binding documentation of the specific driver. + +The cells properties above define that an address of children of an I2C bus +are described by a single value. This is usually a 7 bit address. However, +flags can be attached to the address. I2C_TEN_BIT_ADDRESS is used to mark a 10 +bit address. It is needed to avoid the ambiguity between e.g. a 7 bit address +of 0x50 and a 10 bit address of 0x050 which, in theory, can be on the same bus. +Another flag is I2C_OWN_SLAVE_ADDRESS to mark addresses on which we listen to +be devices ourselves. + +Optional properties +------------------- + +These properties may not be supported by all drivers. However, if a driver +wants to support one of the below features, it should adapt the bindings below. + +- clock-frequency - frequency of bus clock in Hz +- wakeup-source - device can be used as a wakeup source.