FDT bindings for I2C devices
Grant Likely
grant.likely at secretlab.ca
Sat Oct 20 00:38:09 EST 2007
On 10/19/07, Wolfgang Grandegger <wg at grandegger.com> wrote:
> Hello,
>
> is it forseen to define and configure devices like RTC, temperature
> sensors or EEPROM on the I2C bus with the Flat Device Tree? If yes, how
> would the DTS entries look like?
booting-without-of.txt has some information about describing the controller.
Scott Wood made an attempt at defining a device binding for I2C
devices, but it has not been merged into booting-without-of.txt yet.
I've copied what he wrote below. I would add to his definition the
following:
- If compatible is missing, driver should *not* fall back to the device name.
- 'compatible' list should include the exact device in the form "<mfg>,<part>"
Cheers,
g.
Here's the thread and an excerpt from Scott's original post:
http://patchwork.ozlabs.org/linuxppc/patch?id=11223
+ e2) I2C Devices
+
+ Required properties :
+
+ - reg : Unshifted 7-bit I2C address for the device
+
+ Recommended properties :
+
+ - compatible : The name of the Linux device driver that
+ handles this device. If unspecified, the name of the
+ node will be used.
+ - interrupts : <a b> where a is the interrupt number and b is a
+ field that represents an encoding of the sense and level
+ information for the interrupt. This should be encoded based on
+ the information in section 2) depending on the type of interrupt
+ controller you have.
+ - interrupt-parent : the phandle for the interrupt controller that
+ services interrupts for this device.
+
+ Example :
+
+ rtc at 68 {
+ device_type = "rtc";
+ compatible = "ds1374";
+ reg = <68>;
+ interrupts = <13 8>;
+ interrupt-parent = <700>;
+ };
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
grant.likely at secretlab.ca
(403) 399-0195
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