[U-Boot] DM-SERIAL-SPL on MX6

[Hannes Schmelzer <hannes@schmelzer.or.at>]

HI
>> thanks for this hint, i also tried this. But unfortunately without success.
>> But it is good to know that this way on your side works.
>>
>> what i've done to try make it work:
>>
>> add to my dts:
>>      chosen {
>>          stdout-path = &uart1;
>>      };
>>
>> &uart1 {
>>      u-boot,dm-spl;
>>      u-boot,dm-preloc;
>>      status = "okay";
>> };
> Don't you need pins muxing properties in uart1 ( pinctrl-names /
> pinctrl-0 ) ?
No, pinmux is done with:

static iomux_v3_cfg_t const board_pads_spl[] = {
     /* UART#1 PADS */
     MUXDESC(PAD_CSI0_DAT10__UART1_TX_DATA,    UART_PAD_CTRL),
     MUXDESC(PAD_CSI0_DAT11__UART1_RX_DATA,    UART_PAD_CTRL),
}

SETUP_IOMUX_PADS(board_pads_spl);

SPL console output is fine working once DM_SERIAL for SPL is disabled.
But with this option enabled i get no output during spl stage.
Once the full u-boot payload is loaded the console works with DM as 
excpected.

In:    serial at 02020000
Out:   serial at 02020000
Err:   serial at 02020000

=> dm tree
  Class      Probed  Driver      Name
----------------------------------------
  root       [ + ]   root_drive  root_driver
  simple_bus [ + ]   generic_si  |-- soc
  simple_bus [ + ]   generic_si  |   |-- aips-bus at 02000000
  simple_bus [ + ]   generic_si  |   |   |-- spba-bus at 02000000
  spi        [ + ]   mxc_spi     |   |   |   |-- ecspi at 02008000
  spi_flash  [ + ]   spi_flash_  |   |   |   |   `-- spi_flash at 0:1
  serial     [ + ]   serial_mxc  |   |   |   `-- serial at 02020000

>> so the device should be present during spl stage and console should be
>> set to it.
>>
>> # Serial drivers
>> #
>> CONFIG_BAUDRATE=115200
>> CONFIG_SERIAL_PRESENT=y
>> CONFIG_SPL_SERIAL_PRESENT=y
>> CONFIG_DM_SERIAL=y
>> CONFIG_SPL_DM_SERIAL=y
>> CONFIG_MXC_UART=y
>>
>> maybe i'm still missing something.
>>
>
cheers,
Hannes