[U-Boot] [PATCH v4 10/14] OMAP3 SPL: Add identify_nand_chip function

[Igor Grinberg <grinberg@compulab.co.il>]

On 11/21/11 16:12, Tom Rini wrote:
> On Mon, Nov 21, 2011 at 12:04 AM, Igor Grinberg <grinberg@compulab.co.il> wrote:
>> On 11/20/11 16:26, Tom Rini wrote:
>>> On Sun, Nov 20, 2011 at 12:36 AM, Igor Grinberg <grinberg@compulab.co.il> wrote:
>>>> Hi Tom,
>>>>
>>>> On 11/19/11 00:48, Tom Rini wrote:
>>>>> A number of boards are populated with a PoP chip for both DDR and NAND
>>>>> memory.  Other boards may simply use this as an easy way to identify
>>>>> board revs.  So we provide a function that can be called early to reset
>>>>> the NAND chip and return the result of NAND_CMD_READID.  All of this
>>>>> code is put into spl_id_nand.c and controlled via CONFIG_SPL_OMAP3_ID_NAND.
>>>>>
>>>>> Signed-off-by: Tom Rini <trini@ti.com>
>>>>> ---
>>>>>  arch/arm/cpu/armv7/omap3/Makefile           |    3 +
>>>>>  arch/arm/cpu/armv7/omap3/spl_id_nand.c      |   87 +++++++++++++++++++++++++++
>>>>>  arch/arm/include/asm/arch-omap3/sys_proto.h |    1 +
>>>>>  3 files changed, 91 insertions(+), 0 deletions(-)
>>>>>  create mode 100644 arch/arm/cpu/armv7/omap3/spl_id_nand.c
>>>>>
>>>>> diff --git a/arch/arm/cpu/armv7/omap3/Makefile b/arch/arm/cpu/armv7/omap3/Makefile
>>>>> index 8e85891..4b38e45 100644
>>>>> --- a/arch/arm/cpu/armv7/omap3/Makefile
>>>>> +++ b/arch/arm/cpu/armv7/omap3/Makefile
>>>>> @@ -31,6 +31,9 @@ COBJS       += board.o
>>>>>  COBJS        += clock.o
>>>>>  COBJS        += mem.o
>>>>>  COBJS        += sys_info.o
>>>>> +ifdef CONFIG_SPL_BUILD
>>>>> +COBJS-$(CONFIG_SPL_OMAP3_ID_NAND)    += spl_id_nand.o
>>>>> +endif
>>>>
>>>> You haven't responded to my question on the above stuff.
>>>> Otherwise all the series look good to me.
>>>
>>> Missed that, sorry!
>>>
>>>>
>>>> Original version available at:
>>>> http://www.mail-archive.com/u-boot at lists.denx.de/msg68828.html
>>>>
>>>> Here is the relevant part:
>>>>
>>>>>>> diff --git a/arch/arm/cpu/armv7/omap3/Makefile b/arch/arm/cpu/armv7/omap3/Makefile
>>>>>>>>>> index 8e85891..772f3d4 100644
>>>>>>>>>> --- a/arch/arm/cpu/armv7/omap3/Makefile
>>>>>>>>>> +++ b/arch/arm/cpu/armv7/omap3/Makefile
>>>>>>>>>> @@ -31,6 +31,9 @@ COBJS += board.o
>>>>>>>>>>  COBJS  += clock.o
>>>>>>>>>>  COBJS  += mem.o
>>>>>>>>>>  COBJS  += sys_info.o
>>>>>>>>>> +ifdef CONFIG_SPL_BUILD
>>>>>>>>>> +COBJS-$(CONFIG_SPL_OMAP3_POP_PROBE)    += spl_pop_probe.o
>>>>>>>>>> +endif
>>>>>>>>
>>>>>>>> Can't CONFIG_SPL_OMAP3_..._PROBE symbol default to "no"
>>>>>>>> and depend on CONFIG_SPL_BUILD, so you don't need to enclose
>>>>>>>> it in #ifdef?
>>>>>>
>>>>>> But then it would build for both SPL and non-SPL cases.
>>>>
>>>> No, it should not.
>>>> What do you think of the following:
>>>> In the Makefile have only:
>>>> COBJS-$(CONFIG_SPL_OMAP3_POP_PROBE)     += spl_pop_probe.o
>>>>
>>>> Then in the spl_pop_probe.c have this type of check:
>>>> #ifndef CONFIG_SPL_BUILD
>>>> # error CONFIG_SPL_OMAP3_POP_PROBE requires CONFIG_SPL_BUILD
>>>> #endif
>>>>
>>>> This way, you require the CONFIG_SPL_OMAP3_POP_PROBE symbol
>>>> be a part of the CONFIG_SPL_BUILD symbols group.
>>>
>>> Well, if we always link this, but then #error, U-Boot won't build :)
>>
>> No you do not always link this... please, read more carefully...
>> Only when CONFIG_SPL_OMAP3_POP_PROBE symbol is defined, the file will
>> be compiled, but if CONFIG_SPL_OMAP3_POP_PROBE defined without
>> CONFIG_SPL_BUILD being defined, then it will emit an error.
> 
> So make the config file do:
> #ifdef CONFIG_SPL_BUILD
> #define CONFIG_SPL_OMAP3_POP_PROBE
> #endif
> ?  That's now how the rest of the SPL code works.

Well, yes I think it makes sense for all SPL related config options
to do something like:
#ifdef CONFIG_SPL_BUILD
#define CONFIG_SPL_OMAP3_POP_PROBE
#define CONFIG_SPL_...
#define CONFIG_SPL_...
#endif

And the error message, I have proposed above, will prevent
people from doing stupid things, like defining
CONFIG_SPL_OMAP3_POP_PROBE without the CONFIG_SPL_BUILD.
At least for now, until we have Kbuild with dependencies and stuff...

-- 
Regards,
Igor.