[06/10,V2] spi: Add SPI driver for mx233/mx28

[Shawn Guo]

On Wed, Aug 01, 2012 at 09:38:07AM +0200, Lothar Waßmann wrote:
> Shawn Guo writes:
> > On Wed, Aug 01, 2012 at 08:45:19AM +0200, Marek Vasut wrote:
> > > > I must be missing something.  Why do almost all spi drivers call it in the
> > > > error path, even if there is no call to spi_master_get ?
> > > 
> > > To push the refcounting to 0, to deallocate the device, I'd say ...
> > > 
> > It's not going to work if spi_master_put is called without
> > spi_master_get being called before that.
> > 
> spi_alloc_master() calls device_initialize() which resuires a
> device_put() (called from spi_master_put()) to free the device.
> 
Ah, indeed.  I missed that kref_init() will initialize the refcount
to 1.

Thanks,
Shawn