clk: add DT clock binding support

Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant
Likely, this patch adds support to clk_get to allow drivers to retrieve
clock data from the device tree.

Platforms scan for clocks in DT with of_clk_init and a match table, and
the register a provider through of_clk_add_provider. The provider's
clk_src_get function will be called when a device references the
provider's OF node for a clock reference.

v6 (Rob Herring):
    - Return error values instead of NULL to match clock framework
      expectations

v5 (Rob Herring):
    - Move from drivers/of into common clock subsystem
    - Squashed "dt/clock: add a simple provider get function" and
      "dt/clock: add function to get parent clock name"
    - Rebase to 3.4-rc1
    - Drop CONFIG_OF_CLOCK and just use CONFIG_OF
    - Add missing EXPORT_SYMBOL to various functions
    - s/clock-output-name/clock-output-names/
    - Define that fixed-clock binding is a single output

v4 (Rob Herring):
    - Rework for common clk subsystem
    - Add of_clk_get_parent_name function

v3: - Clarified documentation

v2: - fixed errant ';' causing compile error
    - Editorial fixes from Shawn Guo
    - merged in adding lookup to clkdev
    - changed property names to match established convention. After
      working with the binding a bit it really made more sense to follow the
      lead of 'reg', 'gpios' and 'interrupts' by making the input simply
      'clocks' & 'clock-names' instead of 'clock-input-*', and to only use
      clock-output* for the producer nodes. (Sorry Shawn, this will mean
      you need to change some code, but it should be trivial)
    - Add ability to inherit clocks from parent nodes by using an empty
      'clock-ranges' property.  Useful for busses.  I could use some feedback
      on the new property name, 'clock-ranges' doesn't feel right to me.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
clk: add DT fixed-clock binding support

Add support for DT "fixed-clock" binding to the common fixed rate clock
support.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
[Rob Herring] Rework and move into common clock infrastructure
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
iio:axi_adc: Fix CHAN_SEL register address

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
arch: mb: enable COMMOM_CLK infrastructure

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
iio: adc: avoid possible false trigger and simplify dco calibrate routine

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
iio: frequency: cf_axi_dds miscellaneous changes

Remove mem init and wave data. (no longer supported by HDL)
Add debugfs access to PCORE registers.
Add support for 3x HW interpolation.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
iio: frequency: New driver AD9517 SPI Clock Generator with integrated VCO

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
spi: New Analog Devices AD9250-FMC-250EBZ SPI-SPI-bridge driver

This driver adds support for the SPI-SPI bridge CPLD found on the
Analog Devices AD9250-FMC-250EBZ and 4DSP FMC176 and FMX230 FMC cards.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
spi: of_register_spi_devices: add support for SPI_3WIRE

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
iio: adc: Analog Devices AXI-JESD204B Interface Module add clk support

Clocks must be present and stable before the interface is setup.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
iio: adc: AD9250: clocks must be present and stable before device init.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
arch: microblaze: add support for AD9250-FMC-250EBZ

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
arch: microblaze: update ML605 xcomm settings

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>