[U-Boot] [PATCH 03/10] mx23evk: Adjust DRAM control register to use full 128MB of RAM

Otavio Salvador
2013-01-30T16:00:15Z

On Wed, Jan 30, 2013 at 1:55 PM, Marek Vasut <marex@denx.de> wrote:
> Dear Otavio Salvador,
>
>> On Wed, Jan 30, 2013 at 1:38 PM, Marek Vasut <marex@denx.de> wrote:
>> > Dear Otavio Salvador,
>> >
>> >> On Wed, Jan 30, 2013 at 12:12 PM, Marek Vasut <marex@denx.de> wrote:
>> >> > Dear Otavio Salvador,
>> >> >
>> >> >> Adjust HW_DRAM_CTL14 to enable the chip selects to allow usage of
>> >> >> full 128MB of RAM.
>> >> >>
>> >> >> Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
>> >> >
>> >> > Just enable the full set for all in the generic memory register set
>> >> > (dram_vals)?
>> >>
>> >> Per datasheet description it shouldn't be done for LQFP;
>> >
>> > LQFP package is missing pinmux for the other pins, so that's ok.
>> >
>> >> so the safest
>> >> setting is to the default we're using as it will work for new boards
>> >> and the chip select can be adjusted when need.
>> >
>> > And since the block inside the CPU is the same, just missing the pinmux,
>> > it is also safe to enable all CS lines for default operation.
>>
>> If this is the case why they added the CS selector?
>
> CS selector?
>
>> The datasheet is
>> clear about the different setting in BGA and LQFP.
>
> It'd be nice if you gave a ref. into the datasheet where I can find such
> information.
>
>> I'd prefer if
>> someone from Freescale could check if it would be safe to enable them
>> all or not. Fabio? :-)
>
> According to table 12-36 and 37.4 , EMI has two CE lines max (CE0N and CE1N). If
> CE1 is not present on the smaller package, it's not a problem, since whenever
> asserted, the MUX won't let the signal go further. Moreover, the CE line is
> asserted only when particular memory area is accessed.
>
> Thus, CS_MAP shall be 0x3 in default setup.
>
> btw. this patch is misconfiguring INTAREF field which is not documented in the
> commit message.

It is not changing the value of it but setting to the same used in
default setup. So I did not include it in commit log.

I will give it a test in mx23_olinuxino and then if it does work fine
I do the change for v2.

--
Otavio Salvador O.S. Systems
E-mail: otavio at ossystems.com.br http://www.ossystems.com.br
Mobile: +55 53 9981-7854 http://projetos.ossystems.com.br