[U-Boot] [PATCH] samsung: move DRAM parameters
Minkyu Kang
promsoft at gmail.com
Thu Nov 5 12:24:19 CET 2009
Dear Seunghyeon Rhee,
please do not top posting.
2009/11/5 "Seunghyeon Rhee (이승현)" <seunghyeon at lpmtec.com>:
> Dear Minkyu Kang,
>
> What causes the current ambiguity is, in my opinion, the "parameters"
> themselves and "the way of setting them." As you know, DRAM controller
> is integrated in the SoC while the parameters required to set them are
> dependent on the external components, DRAM chips.
>
> In this respect, cpu_init.S - I don't like the name because all it does is
> set up the memory controller. mem_setup.S is more appropriate - don't
> need to be moved to board description stuffs. The memory controller (the
> hardware logic in the SoC) is not changeable according to the board design.
> Neither does the way of setting it, which is in charge of cpu_init.S.
> What is
> changed from board to board is not cpu_init.S but the parameters. If we
> move it to board directory, we have to add redundant code - actually
> several copies of the same file - every time we add support for a new board
> with the same SoC.
>
> Thererfore, I think cpu_init.S(or mem_setup.S) would better be placed with
> SoC stuffs like it is now while DRAM parameters be moved to board
> description stuffs. We can make the function for setting up the DRAM
> controller completely independent of board design by introducing more
> macro definitions if necessary. All we have to do for adding support for
> new boards then will be reduced to creating the new board's description.
> No redundant codes, no repeated modification of the SoC description will
> be required.
Agreed.
But, I'm not sure that move it to board configuration file.
let's figure out and discuss.. including regard your suggestion.
>
> Best regards,
> Seunghyeon
>
> Seunghyeon Rhee, Ph.D. / Director
> LPM Technology Inc.
> T +82-70-8255-6007 F +82-2-6442-6462
> M +82-10-2790-0657
>
>
>
> Minkyu Kang 쓴 글:
>> Dear Seunghyeon Rhee,
>>
>> 2009/11/4 "Seunghyeon Rhee (이승현)" <seunghyeon at lpmtec.com>:
>>
>>> Move the definitions of DRAM parameters from SoC description
>>> (s3c6400.h) to board description (smdk6400.h). DRAM parameters
>>> are rather board-specific than SoC specific. According to the
>>> current source, one may have to change the definitions in
>>> s3c6400.h in addition to creating the new board description
>>> whenever he wants to add support for a new board based on
>>> s3c6400. I don't think this meets the U-Boot policy of
>>> separating SoC description and board description.
>>> There will be no observable changes in operation. It's just
>>> to make it easier to add support for new boards.
>>>
>>> Signed-off-by: Seunghyeon Rhee <seunghyeon at lpmtec.com>
>>> ---
>>> include/configs/smdk6400.h | 21 +++++++++++++++++++++
>>> include/s3c6400.h | 21 ---------------------
>>> 2 files changed, 21 insertions(+), 21 deletions(-)
>>>
>>> diff --git a/include/configs/smdk6400.h b/include/configs/smdk6400.h
>>> index f6e1221..a2b46fd 100644
>>> --- a/include/configs/smdk6400.h
>>> +++ b/include/configs/smdk6400.h
>>> @@ -309,4 +309,25 @@
>>> # error "usb_ohci.c is currently broken with MMU enabled."
>>> #endif
>>>
>>> +/*-----------------------------------------------------------------------
>>> + * Physical Memory Map
>>> + */
>>> +#define DMC1_MEM_CFG 0x80010012 /* Chip1, Burst4, Row/Column bit */
>>> +#define DMC1_MEM_CFG2 0xB45
>>> +#define DMC1_CHIP0_CFG 0x150F8 /* 0x4000_0000 ~ 0x43ff_ffff (64MB) */
>>> +#define DMC_DDR_32_CFG 0x0 /* 32bit, DDR */
>>> +
>>> +/* Memory Parameters */
>>> +/* DDR Parameters */
>>> +#define DDR_tREFRESH 7800 /* ns */
>>> +#define DDR_tRAS 45 /* ns (min: 45ns)*/
>>> +#define DDR_tRC 68 /* ns (min: 67.5ns)*/
>>> +#define DDR_tRCD 23 /* ns (min: 22.5ns)*/
>>> +#define DDR_tRFC 80 /* ns (min: 80ns)*/
>>> +#define DDR_tRP 23 /* ns (min: 22.5ns)*/
>>> +#define DDR_tRRD 15 /* ns (min: 15ns)*/
>>> +#define DDR_tWR 15 /* ns (min: 15ns)*/
>>> +#define DDR_tXSR 120 /* ns (min: 120ns)*/
>>> +#define DDR_CASL 3 /* CAS Latency 3 */
>>> +
>>> #endif /* __CONFIG_H */
>>> diff --git a/include/s3c6400.h b/include/s3c6400.h
>>> index e527c08..34d0d15 100644
>>> --- a/include/s3c6400.h
>>> +++ b/include/s3c6400.h
>>> @@ -814,27 +814,6 @@
>>> #endif
>>>
>>>
>>> -/*-----------------------------------------------------------------------
>>> - * Physical Memory Map
>>> - */
>>> -#define DMC1_MEM_CFG 0x80010012 /* Chip1, Burst4, Row/Column bit */
>>> -#define DMC1_MEM_CFG2 0xB45
>>> -#define DMC1_CHIP0_CFG 0x150F8 /* 0x4000_0000 ~ 0x43ff_ffff (64MB) */
>>> -#define DMC_DDR_32_CFG 0x0 /* 32bit, DDR */
>>> -
>>> -/* Memory Parameters */
>>> -/* DDR Parameters */
>>> -#define DDR_tREFRESH 7800 /* ns */
>>> -#define DDR_tRAS 45 /* ns (min: 45ns)*/
>>> -#define DDR_tRC 68 /* ns (min: 67.5ns)*/
>>> -#define DDR_tRCD 23 /* ns (min: 22.5ns)*/
>>> -#define DDR_tRFC 80 /* ns (min: 80ns)*/
>>> -#define DDR_tRP 23 /* ns (min: 22.5ns)*/
>>> -#define DDR_tRRD 15 /* ns (min: 15ns)*/
>>> -#define DDR_tWR 15 /* ns (min: 15ns)*/
>>> -#define DDR_tXSR 120 /* ns (min: 120ns)*/
>>> -#define DDR_CASL 3 /* CAS Latency 3 */
>>> -
>>> /*
>>> * mDDR memory configuration
>>> */
>>> --
>>> 1.6.2.5
>>>
>>>
>>> --
>>> Seunghyeon Rhee, Ph.D. / Director
>>> LPM Technology Inc.
>>> T +82-70-8255-6007 F +82-2-6442-6462
>>> M +82-10-2790-0657
>>> _______________________________________________
>>> U-Boot mailing list
>>> U-Boot at lists.denx.de
>>> http://lists.denx.de/mailman/listinfo/u-boot
>>>
>>>
>>
>> yes,
>> DRAM parameters are board specific.
>> But I think it is not good way to move DRAM parameters to board
>> configuration file.
>> At first, we need to move cpu/arm1176/s3c64xx/cpu_init.S to board
>> directory. (please see smdkc100/mem_setup.S)
>> And.. let's think about where to move DRAM parameters.
>> Please give your opinion.
>>
>> Thanks
>> Minkyu Kang
>>
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>
Thanks
Minkyu Kang
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