[U-Boot] [[PATCH v2]pandaboard: 1/1] Modification of Elpida DDR2 RAM for Pandaboard-ES Rev B3

[Tom Rini <trini@ti.com>]

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On 11/14/2013 01:43 PM, Hardik Patel wrote:
> 
> 
> On Thu, Nov 14, 2013 at 10:02 PM, Tom Rini <trini@ti.com
> <mailto:trini@ti.com>> wrote:
> On 11/14/2013 11:28 AM, Michael Trimarchi wrote:
>>>> Hi
>>>>
>>>> On Thu, Nov 14, 2013 at 5:19 PM, Tom Rini <trini@ti.com
>> <mailto:trini@ti.com>> wrote:
>>>> On 11/14/2013 05:06 AM, Hardik wrote:
>>>>>>> From: Hardik Patel <hardik.patel@volansystech.com
>> <mailto:hardik.patel@volansystech.com>>
>>>>>>>
>>>>>>> Signed-off-by: Hardik Patel <hardik.patel@volansystech.com
>> <mailto:hardik.patel@volansystech.com>>
>>>>>>> ---
>>>>>>>  arch/arm/cpu/armv7/omap4/sdram_elpida.c |    2 +-
>>>>>>>  board/ti/panda/panda.c                  |   24
>> ++++++++++++++++++++++++
>>>>>>>  2 files changed, 25 insertions(+), 1 deletion(-)
>>>>>>>
>>>>>>> diff --git a/arch/arm/cpu/armv7/omap4/sdram_elpida.c
>> b/arch/arm/cpu/armv7/omap4/sdram_elpida.c
>>>>>>> index e4c8316..9fbdeea 100644
>>>>>>> --- a/arch/arm/cpu/armv7/omap4/sdram_elpida.c
>>>>>>> +++ b/arch/arm/cpu/armv7/omap4/sdram_elpida.c
>>>>>>> @@ -123,7 +123,7 @@ static void emif_get_reg_dump_sdp(u32 emif_nr,
>> const struct emif_regs **regs)
>>>>>>>               *regs = &emif_regs_elpida_200_mhz_2cs;
>>>>>>>       else if (omap4_rev == OMAP4430_ES2_3)
>>>>>>>               *regs = &emif_regs_elpida_400_mhz_1cs;
>>>>>>> -     else if (omap4_rev < OMAP4470_ES1_0)
>>>>>>> +     else if (omap4_rev < OMAP4470_ES1_0 && !is_panda_es_rev_b3())
>>>>>>>               *regs = &emif_regs_elpida_400_mhz_2cs;
>>>>>>>       else
>>>>>>>               *regs = &emif_regs_elpida_400_mhz_1cs;
>>>>>>> diff --git a/board/ti/panda/panda.c b/board/ti/panda/panda.c
>>>>>>> index c104024..5a7f80a 100644
>>>>>>> --- a/board/ti/panda/panda.c
>>>>>>> +++ b/board/ti/panda/panda.c
>>>>>>> @@ -122,6 +122,30 @@ int get_board_revision(void)
>>>>>>>       return board_id;
>>>>>>>  }
>>>>>>>
>>>>>>> +/*
>>>>>>> +* Routine: is_panda_es_rev_b3
>>>>>>> +* Description: Detect if we are running on B3 version of ES panda
>> board,
>>>>>>> +*              This can be done by reading the level of GPIO 171
>>>>>>> +*              and checking the processor revisions.
>>>>>>> +*              GPIO171: 1 => Panda ES Rev B3
>>>>>>> +*/
>>>>>>> +u8 is_panda_es_rev_b3(void)
>>>>>>> +{
>>>>>>> +        int processor_rev = omap_revision();
>>>>>>> +        int ret = 0;
>>>>>>> +
>>>>>>> +        if ((processor_rev >= OMAP4460_ES1_0 &&
>>>>>>> +             processor_rev <= OMAP4460_ES1_1)) {
>>>>>>> +
>>>>>>> +                /* Setup the mux for the common board ID pins
>> (gpio 171) */
>>>>>>> +                writew((IEN | M3),
>> (*ctrl)->control_padconf_core_base + UNIPRO_TX0);
>>>>>>> +
>>>>>>> +                /* if processor_rev is panda ES and GPIO171 is 1,
>> it is rev b3 */
>>>>>>> +                ret = gpio_get_value(PANDA_BOARD_ID_2_GPIO);
>>>>>>> +        }
>>>>>>> +        return ret;
>>>>>>> +}
>>>>>>> +
>>>>>>>  /**
>>>>>>>   * @brief misc_init_r - Configure Panda board specific configurations
>>>>>>>   * such as power configurations, ethernet initialization as phase2 of
>>>>
>>>> This isn't right.  What I was saying is that board/ti/panda/panda.c
>>>> needs to provide its own emif_get_reg_dump function, which will (as
>>>> designed) override the current one from
>>>> arch/arm/cpu/armv7/omap4/sdram_elpida.c
>>>>
>>>>
>>>>> Any problem to have visibility of emif_regs array of lpddr?
> 
> Things that need exposing so that we can do what was intended before
> should be exposed, in <asm/arch-omap4/sys_proto.h> I think.
> 
> 
> Hi Tom, Michel,
> 
> Thanks for your feedback on this.
> 
> We had implemented override of "emif_get_reg_dump" function in panda.c.
> However, we thought checking detection of pandaboard in sdram_elpida.c
> be smaller change and it was also under omap4. However, now I realized
> after discussing that this may break in case of non panda.c OMAP4 boards.
> 
> Based on your feedback,we are going to correct it like below. I am
> trying to explain it in brief:
> 
> 1) We are going to extern emif_regs in <asm/arch-omap4/sys_proto.h>, so
> that we can access them in panda.c
> #ifdef CONFIG_SYS_EMIF_PRECALCULATED_TIMING_REGS
> extern const struct emif_regs emif_regs_elpida_200_mhz_2cs;
> extern const struct emif_regs emif_regs_elpida_380_mhz_1cs;
> extern const struct emif_regs emif_regs_elpida_400_mhz_1cs;
> extern const struct emif_regs emif_regs_elpida_400_mhz_2cs;
> #endif

Minor nit, don't protect externs with #ifdef, that's not required.
Otherwise, sounds like a good plan, thanks.

- -- 
Tom
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