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

Tue Nov 22 16:39:30 CET 2011

On 11/22/2011 07:51 AM, Tom Rini wrote:
> On 11/22/2011 07:33 AM, Igor Grinberg wrote:
>> On 11/21/11 17:33, Tom Rini wrote:
>>> On 11/21/2011 07:41 AM, Igor Grinberg wrote:
>>>> On 11/21/11 16:12, Tom Rini wrote:
>>>>> On Mon, Nov 21, 2011 at 12:04 AM, Igor Grinberg <grinberg at 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 at 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 at 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-$(CONFIG_SPL_OMAP3_ID_NAND)    += spl_id_nand.o
>>>>>>>>> +endif
>>>>>>>>
>>>>>>>> You haven't responded to my question on the above stuff.
>>>>>>>> Otherwise all the series look good to me.
>>>>>>>
>>>>>>> Missed that, sorry!
>>>>>>>
>>>>>>>>
>>>>>>>> Original version available at:
>>>>>>>> http://www.mail-archive.com/u-boot@lists.denx.de/msg68828.html
>>>>>>>>
>>>>>>>> Here is the relevant part:
>>>>>>>>
>>>>>>>>>>> diff --git a/arch/arm/cpu/armv7/omap3/Makefile b/arch/arm/cpu/armv7/omap3/Makefile
>>>>>>>>>>>>>> index 8e85891..772f3d4 100644
>>>>>>>>>>>>>> --- a/arch/arm/cpu/armv7/omap3/Makefile
>>>>>>>>>>>>>> +++ b/arch/arm/cpu/armv7/omap3/Makefile
>>>>>>>>>>>>>> @@ -31,6 +31,9 @@ COBJS += board.o
>>>>>>>>>>>>>>  COBJS  += clock.o
>>>>>>>>>>>>>>  COBJS  += mem.o
>>>>>>>>>>>>>>  COBJS  += sys_info.o
>>>>>>>>>>>>>> +ifdef CONFIG_SPL_BUILD
>>>>>>>>>>>>>> +COBJS-$(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...
>>>
>>> Well, I guess the point I'd try and make is that it's not how SPL is
>>> done today.  Really following the existing format would be (in the
>>> Makefile):
>>> ifdef CONFIG_SPL_BUILD
>>> ifdef CONFIG_SPL_OMAP3_ID_NAND
>>> COBJS-y += spl_id_nand.o
>>> endif
>>> endif
>>
>> This is bad!
>> We don't want the code to look like the above crap, do we?
>> Because next thing will be even worth:
>> ifdef CONFIG_SPL_BUILD
>> ifdef CONFIG_SPL_OMAP3_ID_NAND 
>> ifdef CONFIG_SPL_OMAP3_ID_NAND_SHIT...
>> COBJS-y += spl_id_nand_shit...o
>> endif
>> endif
>> endif
>>
>>>
>>> I can see the point you're making but I'm asking if we need to change
>>> everyone around to your suggested way of building before we can merge
>>> these changes in?  Thanks!
>>
>> Ok. I understand your point. No, I don't think we should.
>> The real question is, do we want it look like the above crap?
>> If not, then please, do it right in this patch and all the rest
>> can be changed later.
>> Also would be nice to make all future patches do the right thing.
> 
> OK, will do.  Thanks!

Well, there's a problem.  spl/Makefile both sets CONFIG_SPL_BUILD and
then says "here's a bunch of core stuff" we need.  So... we can't hide
most CONFIG choices under a CONFIG_SPL_BUILD check.  We can in the
Makefiles however do more:
ifdef CONFIG_SPL_BUILD
COBJS-$(CONFIG_SPL_...) += spl_foo.o
endif
than we do today.

-- 
Tom