Re: [PATCH] mtd: rawnand: ams-delta: Drop board specific partition info

[H. Nikolaus Schaller]

Hi,

> Am 24.03.2019 um 19:59 schrieb Aaro Koskinen <aaro.koskinen@xxxxxx>:
> 
> Hi,
> 
> On Sun, Mar 24, 2019 at 05:48:22PM +0100, Janusz Krzysztofik wrote:
>> Hi Aaro,
>> 
>> Thanks for your review.
>> 
>> On Wednesday, March 20, 2019 2:16:30 AM CET Aaro Koskinen wrote:
>>> On Tue, Mar 19, 2019 at 11:37:18PM +0100, Janusz Krzysztofik wrote:
>>>> After recent modifications, only a hardcoded partition info makes
>>>> the driver device specific.  Other than that, the driver uses GPIO
>>>> exclusively and can be used on any hardware.
>>>> 
>>>> Drop the partition info and use MTD partition parser with default
>>>> list of partition types instead.
>>>> 
>>>> Amstrad Delta users should append the followig partition info to their
>>>                                        ^^^^^^^^
>>> Should be "following".
>>> 
>>>> kernel command line, possibly by embedding it in CONFIG_CMDLINE:
>>>> mtdparts=ams-delta-nand:3584k(Kernel),256k(u-boot),256k(u-boot_params),\
>>>> 256k(Amstrad_LDR),27m(File_system),768k(PBL_reserved).  For their
>>>> convenience, select CONFIG_MTD_CMDLINE_PARTS  symbol from that board
>>>> Kconfig automatically if this NAND driver is also selected.
>>>> 
>>>> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx>
>>>> Cc: Tony Lindgren <tony@xxxxxxxxxxx>
>>> 
>>> Could we move the fixed partition setup to the board file
>>> instead? Otherwise this kind of change is not really nice for the users,
>>> as it will likely break existing setups. The default partition layout
>>> should remain the same.
>> 
>> I'm wondering if it would be acceptable to pass partition info from a .dts 
>> file.  I think that would be a better, more modern approach than adding a new 
>> header under include/linux/platform_data.
> 
> Hmm, I thought there was some generic way to define partitions without
> adding any new headers. But if that is not possible, then I guess your
> CMDLINE proposal is the preferred one..

I am not sure what you exactly need, but partitions can be defined in
the DTS as children of some NAND drivers. Example:
arch/arm/boot/dts/omap3-beagle.dts
So this design pattern could be copied instead of using CMDLINE.