More and more devices feature PLLs and FLLs with the ability to select
between multiple input clocks. In order to better support these devices
a new argument, source, has been added to the set_pll() configuration
API. Using set_clkdiv() is often difficult due to the need to stop the
PLL/FLL before any reconfiguration can be done.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The WM8993 provides digital sidetone paths and also allows each
channel on the audio interface to be routed separtately to the
DACs and ADCs.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Note that the number of slots used internally is specified in terms
of stereo slots while the external API works with mono slots.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

When used without the PLL we were accidentally clearing the MCLK/2
divider, resulting in a double rate SYSCLK when the divider should
have been used.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The WM8993 analogue control is shared with other devices in the same
product line.  Since this is a very substantial proportion of the
driver move the definitions of these controls into a new wm_hubs module
which allows them to be shared between the two.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We need to use the best value we picked, not the last value we
looked at.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The WM8993 is a highly integrated ultra-low power hi-fi CODEC designed
for portable devices such as multimedia phones.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>