[PATCH v4] imx: add i.MX8MN DDR3L evk board support

[Heiko Thiery]

Hi,

Am So., 19. Juni 2022 um 07:59 Uhr schrieb Michael Nazzareno Trimarchi
<michael at amarulasolutions.com>:
>
> Hi
>
> Il sab 18 giu 2022, 23:56 Heiko Thiery <heiko.thiery at gmail.com> ha scritto:
>>
>> Hi Michael, Hi Marek,
>>
>> Am Mi., 15. Juni 2022 um 08:43 Uhr schrieb Michael Nazzareno Trimarchi
>> <michael at amarulasolutions.com>:
>> >
>> > Hi Heiko
>> >
>> > On Wed, Jun 15, 2022 at 8:23 AM Heiko Thiery <heiko.thiery at gmail.com> wrote:
>> > >
>> > > Hi Marek,
>> > >
>> > > [SNIP]
>> > >
>> > > > > diff --git a/board/freescale/imx8mn_evk/spl.c b/board/freescale/imx8mn_evk/spl.c
>> > > > > index 14cb51368f..0d9909a662 100644
>> > > > > --- a/board/freescale/imx8mn_evk/spl.c
>> > > > > +++ b/board/freescale/imx8mn_evk/spl.c
>> > > > > @@ -83,6 +83,15 @@ int power_init_board(void)
>> > > > >  #ifdef CONFIG_IMX8MN_LOW_DRIVE_MODE
>> > > > >         /* Set VDD_SOC/VDD_DRAM to 0.8v for low drive mode */
>> > > > >         pmic_reg_write(dev, PCA9450_BUCK1OUT_DVS0, 0x10);
>> > > > > +#elif defined(CONFIG_TARGET_IMX8MN_DDR3L_EVK)
>> > > > > +       /* Set VDD_SOC to 0.85v for DDR3L at 1600MTS */
>> > > > > +       pmic_reg_write(dev, PCA9450_BUCK1OUT_DVS0, 0x14);
>> > > > > +
>> > > > > +       /* Disable the BUCK2 */
>> > > > > +       pmic_reg_write(dev, PCA9450_BUCK2CTRL, 0x48);
>> > > > > +
>> > > > > +       /* Set NVCC_DRAM to 1.35v */
>> > > > > +       pmic_reg_write(dev, PCA9450_BUCK6OUT, 0x1E);
>> > > > >  #else
>> > > >
>> > > > All this part is not done by the spl pmic driver?
>> > >
>> > > I saw that you added the PCA9450 driver. Do you know if this
>> > > initialization can be done by the driver when CONFIG_SPL_DM_REGULATOR
>> > > is enabled? If I see this correctly, it can't be done. Is that
>> > > correct?
>> >
>> > +&i2c1 {
>> > +       u-boot,dm-spl;
>> > +};
>> > +
>> > +&{/soc at 0/bus at 30800000/i2c at 30a20000/pmic at 4b} {
>> > +       u-boot,dm-spl;
>> > +};
>> > +
>> > +&{/soc at 0/bus at 30800000/i2c at 30a20000/pmic at 4b/regulators} {
>> > +       u-boot,dm-spl;
>> > +};
>> > +
>> > +&pinctrl_i2c1 {
>> > +       u-boot,dm-spl;
>> > +};
>> > +
>> > +&pinctrl_pmic {
>> > +       u-boot,dm-spl;
>> > +};
>> > +
>> >
>> > Maybe something like this should work. Now question is about should be
>> > done in pre-reloc or not
>>
>> It took me a little while to understand what was meant by this. In the
>> meantime I could
>> change the PMIC/Regulator initialization to DT/DM and can make the setting so.
>> What is not clear to me yet is at which point this should be done
>> (regulators_enable_boot_on()). Currently I do it in the board/spl
>> specific board_init_f().
>>
>> Do any of you have any advice here?
>
>
> After having a discussion with you, i found that maybe i have some problem and some of the setting should be done before ddr inizialization. I will take a look on it on afternoon. I know marek was working on some way to probe driver during binding and we need even to be sure that this can happen before memory training.
>

Currently I added it in  board_init_f() right before spl_dram_init()
[1] and it works. I also tried to put it in power_init_board() [2] but
this does not work.

[1] https://elixir.bootlin.com/u-boot/v2022.04/source/board/freescale/imx8mn_evk/spl.c#L162
[2] https://elixir.bootlin.com/u-boot/v2022.04/source/board/freescale/imx8mn_evk/spl.c#L62

--
Heiko

> Michael
>>
>>
>> Thanks
>> --
>> Heiko
>>
>> > Michael
>> > >
>> > > --
>> > > Heiko
>> >
>> >
>> >
>> > --
>> > Michael Nazzareno Trimarchi
>> > Co-Founder & Chief Executive Officer
>> > M. +39 347 913 2170
>> > michael at amarulasolutions.com
>> > __________________________________
>> >
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