On Thu, Jan 03, 2013 at 12:05:20PM +0300, Dan Carpenter wrote:

On Wed, Jan 02, 2013 at 06:31:53PM +1300, Tony Prisk wrote:

quoted

Why should a _consumer_ of a clock care?  It is _very_ important that
people get this idea - to a consumer, the struct clk is just an opaque
cookie.  The fact that it appears to be a pointer does _not_ mean that
the driver can do any kind of dereferencing on that pointer - it should
never do so.

Thread can be viewed here:
https://lkml.org/lkml/2012/12/20/105

Ah.  Grand.  Thanks...

Btw. The documentation for clk_get() really should include some of
this information.

It *does* contain this information.  The problem is that driver authors
_ARE_ stupid, lazy morons who don't bother to read documentation.

/**
 * clk_get - lookup and obtain a reference to a clock producer.
 * @dev: device for clock "consumer"
 * @id: clock consumer ID
 *
 * Returns a struct clk corresponding to the clock producer, or
 * valid IS_ERR() condition containing errno.  The implementation
 * uses @dev and @id to determine the clock consumer, and thereby
 * the clock producer.  (IOW, @id may be identical strings, but
 * clk_get may return different clock producers depending on @dev.)
 *
 * Drivers must assume that the clock source is not enabled.
 *
 * clk_get should not be called from within interrupt context.
 */