[PATCH v4 3/3] powerpc: doc/dts-bindings: update doc of FSL I2C bindings
Wolfgang Grandegger
wg at grandegger.com
Wed Feb 10 06:23:04 EST 2010
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
-------------
Wolfgang.
More information about the Linuxppc-dev
mailing list