<linux/clk.h> should be included to get the base API prototypes.

This fixes the following sparse warnings:

  arch/arm/common/clkdev.c:65:12:
    warning: symbol 'clk_get_sys' was not declared. Should it be static?

  arch/arm/common/clkdev.c:79:12:
    warning: symbol 'clk_get' was not declared. Should it be static?

  arch/arm/common/clkdev.c:87:6:
    warning: symbol 'clk_put' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This can be used for other arm platforms too as discussed
on the linux-arm-kernel list.

Also check the return value with IS_ERR and return PTR_ERR
as suggested by Russell King.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This adds clk_get_sys to get a clock without the associated struct
device.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

The old matching algorithm was too fuzzy, causing false positives.
For example, when asked for device D connection C1 and we only find
device D connection C2, we return that as a valid match despite the
connection names being different.

Change the algorithm such that:
  An entry with a NULL ID is assumed to be a wildcard.
  If an entry has a device ID, it must match
  If an entry has a connection ID, it must match

However, we maintain the order of precidence while still only doing
a single pass over all entries: dev+con > dev only > con only.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Add some generic infrastructure to assist looking up struct clks
for the ARM architecture.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>