Re: [PATCH V2 3/9] ARM: stm32: prepare stm32 family to welcome armv7 architecture

[Arnd Bergmann]

On Tue, Dec 19, 2017 at 3:43 PM, Ludovic BARRE <ludovic.barre@xxxxxx> wrote:
>
>
> On 12/18/2017 09:24 PM, Arnd Bergmann wrote:
>>
>> On Mon, Dec 18, 2017 at 4:17 PM, Ludovic Barre <ludovic.Barre@xxxxxx>
>> wrote:
>>>
>>> From: Ludovic Barre <ludovic.barre@xxxxxx>
>>>
>>> This patch prepares the STM32 machine for the integration of Cortex-A
>>> based microprocessor (MPU), on top of the existing Cortex-M
>>> microcontroller family (MCU). Since both MCUs and MPUs are sharing
>>> common hardware blocks we can keep using ARCH_STM32 flag for most of
>>> them. If a hardware block is specific to one family we can use either
>>> ARM_SINGLE_ARMV7M or ARCH_MULTI_V7 flag.
>>>
>>> Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
>>
>>
>> Looks good overall. Two more small comments:
>>
>>
>>>
>>> +if ARCH_STM32
>>> +
>>>   config MACH_STM32F429
>>> -       bool "STMicrolectronics STM32F429"
>>> -       depends on ARCH_STM32
>>> +       bool "STMicroelectronics STM32F429"
>>> +       depends on ARM_SINGLE_ARMV7M
>>>          default y
>>
>>
>> Instead of the explicit dependency for each board, I'd leave the
>> surrounding
>> 'if ARM_SINGLE_ARMV7M'. I think you had in v1.
>
>
> As you suggest, I follow mach-at91 example.
> The point is on "depends on ARM_SINGLE_ARMV7M" ?
> You prefer this way:
> config MACH_STM32F429
>         bool "STMicroelectronics STM32F429" if ARM_SINGLE_ARMV7M
>         default y
>

No, that would be wrong, that way you would always enable
MACH_STM32F429 when ARM_SINGLE_ARMV7M is turned
off, which is exactly the wrong way round. What I meant is

if ARCH_STM32

if ARM_SINGLE_ARMV7M

config MACH_STM32F429
         bool "STMicrolectronics STM32F429"

config MACH_STM32...
          ...

endif # ARMv7-M

if ARCH_MULTI_V7

config MACH_STM32...
          ...

endif # ARMv7-A

endif # STM32

       Arnd