[U-Boot] pre_probe under struct driver

[Simon Glass]

Hi Keerthy,

On Tue, 4 Jun 2019 at 14:01, Keerthy <j-keerthy at ti.com> wrote:
>
> Hi Simon/Tom,
>
> I am looking at the device_probe function in drivers/core/device.c
>
> ret = uclass_pre_probe_device(dev);
>          if (ret)
>                  goto fail;
>
>          if (dev->parent && dev->parent->driver->child_pre_probe) {
>                  ret = dev->parent->driver->child_pre_probe(dev);
>                  if (ret)
>                          goto fail;
>          }
>
>          if (drv->ofdata_to_platdata && dev_has_of_node(dev)) {
>                  ret = drv->ofdata_to_platdata(dev);
>                  if (ret)
>                          goto fail;
>          }
>
>          /* Process 'assigned-{clocks/clock-parents/clock-rates}'
> properties */
>          ret = clk_set_defaults(dev);
>
> In case of a device like MPU we would like setup voltage before setting
> the clocks and i was looking if we can have a pre_probe for a driver
> to do things before driver gets probed. Neither uclass_pre_probe_device
> nor dev->parent->driver->child_pre_probe benefit me in this case.
>
> Does my situation warrant adding a new hook to struct driver? Or are
> there instances of such handling already in u-boot.

For now, is it enough to probe the power driver from the clock driver?

Regards,
Simon