| Message ID | 1467191877-26017-7-git-send-email-jonathanh@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jun 29, 2016 at 10:17:52AM +0100, Jon Hunter wrote: > The I2C driver core for boards using device-tree assumes any subnode of > an I2C adapter in the device-tree blob is an I2C slave device. Although > this makes complete sense, some I2C adapters may have subnodes which > are not I2C slaves but subnodes presenting other features. For example > some Tegra devices have an I2C interface which may share its pins with > other devices. In order to share these pins using the pinctrl framework, > it is necessary to add subnodes to the I2C device node that represent > these pins. > > To allow I2C adapters to have non-I2C specific subnodes in device-tree > that are not parsed by the I2C driver core, add support for an optional > 'i2c-bus' subnode where I2C slaves can be placed. If the 'i2c-bus' > subnode is present then all I2C slaves must be placed under this > subnode. > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > Acked-by: Thierry Reding <treding@nvidia.com> > Acked-by: Rob Herring <robh@kernel.org> Acked-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt index f31b2ad1552b..5fa691e6f638 100644 --- a/Documentation/devicetree/bindings/i2c/i2c.txt +++ b/Documentation/devicetree/bindings/i2c/i2c.txt @@ -32,6 +32,14 @@ wants to support one of the below features, it should adapt the bindings below. - clock-frequency frequency of bus clock in Hz. +- i2c-bus + For I2C adapters that have child nodes that are a mixture of both I2C + devices and non-I2C devices, the 'i2c-bus' subnode can be used for + populating I2C devices. If the 'i2c-bus' subnode is present, only + subnodes of this will be considered as I2C slaves. The properties, + '#address-cells' and '#size-cells' must be defined under this subnode + if present. + - i2c-scl-falling-time-ns Number of nanoseconds the SCL signal takes to fall; t(f) in the I2C specification.