[u-boot][PATCH 1/3] scripts: Makefile.spl: Enable memory drivers to be built for SPL

[Roger Quadros]

Simon,

On 29/09/2022 21:06, Simon Glass wrote:
> Hi Roger,
> 
> On Thu, 29 Sept 2022 at 01:03, Roger Quadros <rogerq at kernel.org> wrote:
>>
>> Hi Simon,
>>
>> On 28/09/2022 19:27, Simon Glass wrote:
>>> Hi Roger,
>>>
>>> On Wed, 28 Sept 2022 at 06:12, Roger Quadros <rogerq at kernel.org> wrote:
>>>>
>>>> We will need ti-gpmc driver for SPL. Allow memory drivers
>>>> do be built for SPL.
>>>>
>>>> Signed-off-by: Roger Quadros <rogerq at kernel.org>
>>>> ---
>>>>  scripts/Makefile.spl | 1 +
>>>>  1 file changed, 1 insertion(+)
>>>
>>> Please can you use the existing drivers/ram directory?
>>
>> The ti-gpmc driver is not actually a RAM only controller. Although it can support SRAM.
>> It is a more general purpose controller that can support different peripherals.
>> It is similar to the drivers already existing in the divers/memory directory.
>>
>> I was just trying to keep the file layout similar to that in the Linux kernel.
>>
>> Do you still see a problem with it?
> 
> Well in this case perhaps the RAM device would be a child of this one?

That's right.
> 
> But there is no uclass for your new device. One of the drivers in that
> dir uses UCLASS_NOP and your one seems to use UCLASS_SIMPLE_BUS
> 
> So let's add a uclass for it and describe exactly what it is for.

Why isn't UCLASS_SIMPLE_BUS sufficient?
By itself, the GPMC driver doesn't offer any usable functionality.
It just configures the bus interface and then populates the children.

cheers,
-roger