soft_spi does not get probed in DM

[Fabio Estevam]

Hi Jagan,

On a mx7dsabresd board I am not being able to probe the soft_spi
driver using DM with mainline U-Boot.

Device tree used is the same one as used in the kernel (imx7d-sdb.dts).

soft_spi driver is used to communicate with a I/O expander (supported
via CONFIG_DM_74X164), but it can't get probed:

 spi           0  [   ]   soft_spi              |-- spi4

which causes the the I/O expander to not get probed as well.

What needs to be done for soft_spi to get probed in DM?

The "spi-gpio" compatible is present, CONFIG_SPI_SOFT is enabled.

We need to use the I/O expander to reset the Ethernet PHY and bring
Ethernet functionality back.

Thanks,

Fabio Estevam