[PATCH v4 3/3] powerpc: doc/dts-bindings: update doc of FSL I2C bindings
Grant Likely
grant.likely at secretlab.ca
Wed Feb 10 09:15:02 EST 2010
On Tue, Feb 9, 2010 at 12:23 PM, Wolfgang Grandegger <wg at grandegger.com> wrote:
> Wolfgang Grandegger wrote:
>> Hi Grant,
>>
>> Grant Likely wrote:
>>> On Thu, Jan 28, 2010 at 6:25 AM, Wolfgang Grandegger <wg at grandegger.com> wrote:
>>>> From: Wolfgang Grandegger <wg at denx.de>
>>>>
>>>> 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 at denx.de>
>>> 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.
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