Re: [PATCH v4 3/3] powerpc: doc/dts-bindings: update doc of FSL I2C bindings

[Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

On Tue, Feb 9, 2010 at 12:23 PM, Wolfgang Grandegger <wg-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org> wrote:
> Wolfgang Grandegger wrote:
>> Hi Grant,
>>
>> Grant Likely wrote:
>>> On Thu, Jan 28, 2010 at 6:25 AM, Wolfgang Grandegger <wg@grandegger.com> wrote:
>>>> From: Wolfgang Grandegger <wg-ynQEQJNshbs@public.gmane.org>
>>>>
>>>> This patch adds the MPC5121 to the list of supported devices,
>>>> enhances the doc of the "clock-frequency" property and removes
>>>> the obsolete "cell-index" property from the example nodes.
>>>> Furthermore and example for the MPC5121 has been added.
>>>>
>>>> Signed-off-by: Wolfgang Grandegger <wg-ynQEQJNshbs@public.gmane.org>
>>> Thanks Wolfgang.  Comments below.
>>>
>>>> ---
>>>>  Documentation/powerpc/dts-bindings/fsl/i2c.txt |   30 +++++++++++++++++++----
>>>>  1 files changed, 24 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/Documentation/powerpc/dts-bindings/fsl/i2c.txt b/Documentation/powerpc/dts-bindings/fsl/i2c.txt
>>>> index b6d2e21..2f62dae 100644
>>>> --- a/Documentation/powerpc/dts-bindings/fsl/i2c.txt
>>>> +++ b/Documentation/powerpc/dts-bindings/fsl/i2c.txt
>>>> @@ -9,8 +9,9 @@ Recommended properties :
>>>>
>>>>  - compatible : compatibility list with 2 entries, the first should
>>>>    be "fsl,CHIP-i2c" where CHIP is the name of a compatible processor,
>>>> -   e.g. mpc8313, mpc8543, mpc8544, mpc5200 or mpc5200b. The second one
>>>> -   should be "fsl-i2c".
>>>> +   e.g. mpc8313, mpc8543, mpc8544, mpc5121, mpc5200 or mpc5200b. The
>>>> +   second one should be "fsl-i2c". For the mpc5121, an additional node
>>>> +   "fsl,mpc5121-i2c-ctrl" is required as shown in the example below.
>>> While you're editing this line; drop the requirement for the second
>>> value to be 'fsl-i2c'.  We don't use it anymore, and only preserve it
>>> for backwards compatibility with old trees.
>>
>> OK.
>>
>>>>  - 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
>>>> @@ -20,29 +21,46 @@ Recommended properties :
>>>>    services interrupts for this device.
>>>>  - fsl,preserve-clocking : boolean; if defined, the clock settings
>>>>    from the bootloader are preserved (not touched).
>>>> - - clock-frequency : desired I2C bus clock frequency in Hz.
>>>> + - clock-frequency : desired I2C bus clock frequency in Hz.  If this
>>>> +   property and "fsl,preserve-clocking" is not defined, a safe fixed
>>>> +   clock divider value is used (resulting in a small clock frequency).
>>> Nah, leave this as is.  Don't make it sound like omitting both
>>> properties is a valid option.  The driver may (and should!) handle the
>>> situation gracefully, but that fact does not need to be documented.
>>
>> The safe value is not a good choice, indeed. Then it will also change
>> MPC_I2C_CLOCK_SAFE to MPC_I2C_CLOCK_LEGACY in i2c-mpc.c.
>>
>> I will also fix the other issues you commented on.
>
> And I will also remove the "device_type" line from:
>
>  -------------
>  Required properties :
>
>  - device_type : Should be "i2c"
>  - reg : Offset and length of the register set for the device

Yes, please.

Hmmm.  compatible should also be in the 'required properties' section.

Thanks,
g.