[PATCH 1/4] powerpc: Document device nodes for I2C devices.

[PATCH 1/4] powerpc: Document device nodes for I2C devices.

[Scott Wood]

Document the use of device trees to describe devices on an I2C bus, which
will be used with David Brownell's "new style" I2C binding patches.

Signed-off-by: Scott Wood <scottwood@freescale.com>
---
 Documentation/powerpc/booting-without-of.txt |   34 ++++++++++++++++++++++++++
 1 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index 27b457c..092b8f3 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -1277,6 +1277,8 @@ platforms are moved over to use the flat
 
    e) I2C
 
+   e1) I2C Controller
+
    Required properties :
 
     - device_type : Should be "i2c"
@@ -1297,6 +1299,10 @@ platforms are moved over to use the flat
       a digital filter sampling rate register
     - fsl5200-clocking : boolean; if defined, indicated that this device
       uses the FSL 5200 clocking mechanism.
+    - #address-cells : should exist and be 1 if I2C devices are declared
+      in the device tree.
+    - #size-cells : should exist and be 0 if I2C devices are declared
+      in the device tree.
 
    Example :
 
@@ -1309,6 +1315,34 @@ platforms are moved over to use the flat
 		dfsrr;
 	};
 
+   e2) I2C Devices
+
+   Required properties :
+
+    - reg : 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@68 {
+		device_type = "rtc";
+		compatible = "ds1374";
+		reg = <68>;
+		interrupts = <13 8>;
+		interrupt-parent = <700>;
+	};
 
    f) Freescale SOC USB controllers
 
-- 
1.4.2.3

Re: [PATCH 1/4] powerpc: Document device nodes for I2C devices.

[Kumar Gala]

On Dec 7, 2006, at 11:33 AM, Scott Wood wrote:

> Document the use of device trees to describe devices on an I2C bus,  
> which
> will be used with David Brownell's "new style" I2C binding patches.
>
> Signed-off-by: Scott Wood <scottwood@freescale.com>
> ---
>  Documentation/powerpc/booting-without-of.txt |   34 +++++++++++++++ 
> +++++++++++
>  1 files changed, 34 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/powerpc/booting-without-of.txt b/ 
> Documentation/powerpc/booting-without-of.txt
> index 27b457c..092b8f3 100644
> --- a/Documentation/powerpc/booting-without-of.txt
> +++ b/Documentation/powerpc/booting-without-of.txt
> @@ -1277,6 +1277,8 @@ platforms are moved over to use the flat
>
>     e) I2C
>
> +   e1) I2C Controller
> +
>     Required properties :
>
>      - device_type : Should be "i2c"
> @@ -1297,6 +1299,10 @@ platforms are moved over to use the flat
>        a digital filter sampling rate register
>      - fsl5200-clocking : boolean; if defined, indicated that this  
> device
>        uses the FSL 5200 clocking mechanism.
> +    - #address-cells : should exist and be 1 if I2C devices are  
> declared
> +      in the device tree.
> +    - #size-cells : should exist and be 0 if I2C devices are declared
> +      in the device tree.
>
>     Example :
>
> @@ -1309,6 +1315,34 @@ platforms are moved over to use the flat
>  		dfsrr;
>  	};
>
> +   e2) I2C Devices
> +
> +   Required properties :
> +
> +    - reg : I2C address for the device

Is this a 7-bit or 8-bit padded address?

- kumar

Re: [PATCH 1/4] powerpc: Document device nodes for I2C devices.

[Scott Wood]

Kumar Gala wrote:
> On Dec 7, 2006, at 11:33 AM, Scott Wood wrote:
>> +    - reg : I2C address for the device
> 
> 
> Is this a 7-bit or 8-bit padded address?

It's a 7-bit address.

-Scott

Re: [PATCH 1/4] powerpc: Document device nodes for I2C devices.

[Kumar Gala]

On Dec 8, 2006, at 11:56 AM, Scott Wood wrote:

> Kumar Gala wrote:
>> On Dec 7, 2006, at 11:33 AM, Scott Wood wrote:
>>> +    - reg : I2C address for the device
>> Is this a 7-bit or 8-bit padded address?
>
> It's a 7-bit address.

Was chatting with Ben about this and we should try to mimic the  
behavior of I2C in the device-tree that exists on Apple HW.  He was  
going to look at a tree and let us know if they use 7-bit or 8-bit  
addresses.

- k