Re: [PATCH v5 04/12] spi: add ti-ssp spi master driver

[Mark Brown <broonie@opensource.wolfsonmicro.com>]

On Tue, Nov 16, 2010 at 12:47:04AM -0700, Grant Likely wrote:
> On Tue, Nov 16, 2010 at 12:22 AM, Grant Likely

> > Instead, it is now incumbent on the board support code to ensure that
> > any device that depends on another device (including i2c or spi
> > regulators) will defer registration until the prerequisite devices are
> > bound to drivers.

You did also say you were going to write helpers to make this easier - I
do fear that we're going to end up with far too much boiler plate code
in machine drivers if we have to open code this.  I guess device tree is
going to need the helpers anyway :)

> > I don't *think* this change will affect anything in this particular
> > patch series, but if it does then let me know and I'll help you work out
> > how to fix it using a bus notifier.

> Oh, wait, spoke too soon.  You do add a regulator in this series, so
> this change will require a fixup.  The solution is to register an
> bus_notifier to the spi bus type before you start registering devices.

> It also requires deferring the musb_hdrc.1 and tps6116x registrations
> until the bus_notifier callback gets called with an indication that
> the regulator is bound.  It will look something like this:

Did you come up with a way of handling situations like cpufreq where we
have no device to wait for?