Re: [RESEND PATCH v4 1/2] dt-bindings: at24: Add address-width property

From: Bartosz Golaszewski
Date: Tue Jul 17 2018 - 04:01:21 EST


2018-07-09 10:52 GMT+02:00 Bartosz Golaszewski <brgl@xxxxxxxx>:
> 2018-07-09 5:12 GMT+02:00 Chiang, AlanX <alanx.chiang@xxxxxxxxx>:
>> Hi Robert,
>>
>>> -----Original Message-----
>>> From: Robert P. J. Day [mailto:rpjday@xxxxxxxxxxxxxx]
>>> Sent: Friday, July 6, 2018 4:24 AM
>>> To: Rob Herring <robh@xxxxxxxxxx>
>>> Cc: Chiang, AlanX <alanx.chiang@xxxxxxxxx>; linux-i2c@xxxxxxxxxxxxxxx; Yeh,
>>> Andy <andy.yeh@xxxxxxxxx>; sakari.ailus@xxxxxxxxxxxxxxx;
>>> andriy.shevchenko@xxxxxxxxxxxxxxx; Shevchenko, Andriy
>>> <andriy.shevchenko@xxxxxxxxx>; Mani, Rajmohan
>>> <rajmohan.mani@xxxxxxxxx>; andy.shevchenko@xxxxxxxxx;
>>> tfiga@xxxxxxxxxxxx; jcliang@xxxxxxxxxxxx; brgl@xxxxxxxx;
>>> mark.rutland@xxxxxxx; arnd@xxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx;
>>> linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx
>>> Subject: Re: [RESEND PATCH v4 1/2] dt-bindings: at24: Add address-width
>>> property
>>>
>>> On Thu, 5 Jul 2018, Rob Herring wrote:
>>>
>>> > On Mon, Jul 02, 2018 at 05:12:19PM +0800, alanx.chiang@xxxxxxxxx wrote:
>>> > > From: Alan Chiang <alanx.chiang@xxxxxxxxx>
>>> > >
>>> > > The AT24 series chips use 8-bit address by default. If some chips
>>> > > would like to support more than 8 bits, the at24 driver should be
>>> > > added the compatible field for specfic chips.
>>> > >
>>> > > Provide a flexible way to determine the addressing bits through
>>> > > address-width in this patch.
>>> > >
>>> > > Signed-off-by: Alan Chiang <alanx.chiang@xxxxxxxxx>
>>> > > Signed-off-by: Andy Yeh <andy.yeh@xxxxxxxxx>
>>> > > Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
>>> > >
>>> > > ---
>>> > > since v1:
>>> > > -- Remove the address-width field in the example.
>>> > > since v2:
>>> > > -- Remove redundant space.
>>> > > since v3:
>>> > > -- Add Acked-by.
>>> > >
>>> > > ---
>>> > > Documentation/devicetree/bindings/eeprom/at24.txt | 2 ++
>>> > > 1 file changed, 2 insertions(+)
>>> >
>>> > Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
>>>
>>> "... should be added the compatible field ..."??
>>>
>>> rday
>>
>> Maybe I should modify the sentence as below that makes it clear.
>> "The compatible field should be added in the at24.c for specific chips.".
>>
>> I quote Andy's words in patch v2:
>> "The current at24 driver has no address width support, thus, reusing same
>> (allocated) IDs (non-DT case) is hard."
>>
>> This is the reason that I submitted the patch.
>>
>> Thanks
>>
>
> Make it something like:
>
> Currently the only way to use a variant of a supported model with
> a different address width is to define a new compatible string and the
> corresponding chip data structure.
>
> Provide a flexible way to specify the size of the address pointer by
> defining a new property: address-width.
>
> Best regards,
> Bartosz Golaszewski
>
>>>
>>> --
>>>
>>> ==========================================================
>>> ==============
>>> Robert P. J. Day Ottawa, Ontario, CANADA
>>> http://crashcourse.ca/dokuwiki
>>>
>>> Twitter: http://twitter.com/rpjday
>>> LinkedIn: http://ca.linkedin.com/in/rpjday
>>> ==========================================================
>>> ==============

Hi,

I will soon be sending my pull request to Wolfram, so if you still
want that applied for 4.19 - please resend with the commit message
fixed.

Thanks,
Bart