Some driver is using this type of DT bindings for clock (more detail,
see ${LINUX}/Documentation/devicetree/bindings/sound/simple-card.txt).

	sound_soc {
		...
		cpu {
			clocks = <&xxx>;
			...
		};
		codec {
			clocks = <&xxx>;
			...
		};
	};

Current driver in this case uses of_clk_get() for each node, but there
is no devm_of_clk_get() today.
OTOH, the problem of having devm_of_clk_get() is that it encourages the
use of of_clk_get() when clk_get() is more desirable.

Thus, this patch adds new devm_get_clk_from_chile() which explicitly
reads as get a clock from a child node of this device.
By this function, we can also use this type of DT bindings

	sound_soc {
		clocks = <&xxx>, <&xxx>;
		clock-names = "cpu", "codec";
		clock-ranges;
		...
		cpu {
			...
		};
		codec {
			...
		};
	};

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
[sboyd@codeurora.org: Rename subject to clk + add API]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Pull clk updates from Michael Turquette:
 "The bulk of the changes are updates and fixes to existing clk provider
  drivers, along with a pretty standard number of new drivers.  The core
  recieved a small number of updates as well.

  Core changes of note:
   - removed CLK_IS_ROOT flag

  New clk provider drivers:
   - Renesas r8a7796 clock pulse generator / module standby and
     software reset
   - Allwinner sun8i H3 clock controller unit
   - AmLogic meson8b clock controller (rewritten)
   - AmLogic gxbb clock controller
   - support for some new ICs was added by simple changes to static
     data tables for chips sharing the same family

  Driver updates of note:
   - the Allwinner sunxi clock driver infrastucture was rewritten to
     comform to the state of the art at drivers/clk/sunxi-ng.  The old
     implementation is still supported for backwards compatibility with
     the DT ABI"

* tag 'clk-for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (162 commits)
  clk: Makefile: re-sort and clean up
  Revert "clk: gxbb: expose CLKID_MMC_PCLK"
  clk: samsung: Allow modular build of the Audio Subsystem CLKCON driver
  clk: samsung: make clk-s5pv210-audss explicitly non-modular
  clk: exynos5433: remove CLK_IGNORE_UNUSED flag from SPI clocks
  clk: oxnas: Add hardware dependencies
  clk: imx7d: do not set parent of ethernet time/ref clocks
  ARM: dt: sun8i: switch the H3 to the new CCU driver
  clk: sunxi-ng: h3: Fix Kconfig symbol typo
  clk: sunxi-ng: h3: Fix audio clock divider offset
  clk: sunxi-ng: Add H3 clocks
  clk: sunxi-ng: Add N-K-M-P factor clock
  clk: sunxi-ng: Add N-K-M Factor clock
  clk: sunxi-ng: Add N-M-factor clock support
  clk: sunxi-ng: Add N-K-factor clock support
  clk: sunxi-ng: Add M-P factor clock support
  clk: sunxi-ng: Add divider
  clk: sunxi-ng: Add phase clock support
  clk: sunxi-ng: Add mux clock support
  clk: sunxi-ng: Add gate clock support
  ...

The clk notifier symbols are hidden by COMMON_CLK.  However on some
platforms HAVE_CLK might be set while COMMON_CLK not which leads to
compile test build errors like:

$ make.cross ARCH=sh
   drivers/devfreq/tegra-devfreq.c: In function 'tegra_actmon_rate_notify_cb':
>> drivers/devfreq/tegra-devfreq.c:391:16: error: 'POST_RATE_CHANGE' undeclared (first use in this function)
     if (action != POST_RATE_CHANGE)
                   ^
   drivers/devfreq/tegra-devfreq.c: In function 'tegra_devfreq_probe':
>> drivers/devfreq/tegra-devfreq.c:654:8: error: implicit declaration of function 'clk_notifier_register' [-Werror=implicit-function-declaration]
     err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb);
           ^

Export the macros and data type declarations outside of COMMON_CLK ifdef
and provide stubs to fix the compile testing.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

When compiling with the COMPILE_TEST option set, the clps711x does not
compile because of the clk_get_sys() noop stub missing.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Michael Turquette <mturquette@baylibre.com>

clk_add_alias() is provided by clkdev, and is not part of the clk API.
Howver, it is prototyped in two locations: linux/clkdev.h and
linux/clk.h.  This is a mess.  Get rid of the redundant and unnecessary
version in linux/clk.h.

Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The idea is that rate = clk_round_rate(clk, r) is equivalent to:

	clk_set_rate(clk, r);
	rate = clk_get_rate(clk);

except that clk_round_rate() does not change the hardware in any way.

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

Some drivers compare struct clk pointers as a means of knowing
if the two pointers reference the same clock hardware. This behavior is
dubious (drivers must not dereference struct clk), but did not cause any
regressions until the per-user struct clk patch was merged. Now the test
for matching clk's will always fail with per-user struct clk's.

clk_is_match is introduced to fix the regression and prevent drivers
from comparing the pointers manually.

Fixes: 035a61c314eb ("clk: Make clk API return per-user struct clk instances")
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[arnd@arndb.de: Fix COMMON_CLK=N && HAS_CLK=Y config]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[sboyd@codeaurora.org: const arguments to clk_is_match() and
remove unnecessary ternary operation]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Adds a way for clock consumers to set maximum and minimum rates. This
can be used for thermal drivers to set minimum rates, or by misc.
drivers to set maximum rates to assure a minimum performance level.

Changes the signature of the determine_rate callback by adding the
parameters min_rate and max_rate.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
[sboyd@codeaurora.org: set req_rate in __clk_init]
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: min/max rate for sun6i_ahb1_clk_determine_rate
                        migrated clk-private.h changes to clk.c]

This new function is similar to clk_set_parent(), except that it doesn't
actually change the parent. It merely checks that the given parent clock
can be a parent for the given clock.

A situation where this is useful is to check that a particular setup is
valid before switching to it. One specific use-case for this is atomic
modesetting in the DRM framework where setting a mode is divided into a
check phase where a given configuration is validated before applying
changes to the hardware.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

Pull clock tree updates from Mike Turquette:
 "The clk tree changes for 3.18 are dominated by clock drivers.  Mostly
  fixes and enhancements to existing drivers as well as new drivers.
  This tag contains a bit more arch code than I usually take due to some
  OMAP2+ changes.  Additionally it contains the restart notifier
  handlers which are merged as a dependency into several trees.

  The PXA changes are the only messy part.  Due to having a stable tree
  I had to revert one patch and follow up with one more fix near the tip
  of this tag.  Some dead code is introduced but it will soon become
  live code after 3.18-rc1 is released as the rest of the PXA family is
  converted over to the common clock framework.

  Another trend in this tag is that multiple vendors have started to
  push the complexity of changing their CPU frequency into the clock
  driver, whereas this used to be done in CPUfreq drivers.

  Changes to the clk core include a generic gpio-clock type and a
  clk_set_phase() function added to the top-level clk.h api.  Due to
  some confusion on the fbdev mailing list the kernel boot parameters
  documentation was updated to further explain the clk_ignore_unused
  parameter, which is often required by users of the simplefb driver.

  Finally some fixes to the locking around the clock debugfs stuff was
  done to prevent deadlocks when interacting with other subsystems."

* tag 'clk-for-linus-3.18' of git://git.linaro.org/people/mike.turquette/linux: (99 commits)
  clk: pxa clocks build system fix
  Revert "arm: pxa: Transition pxa27x to clk framework"
  clk: samsung: register restart handlers for s3c2412 and s3c2443
  clk: rockchip: add restart handler
  clk: rockchip: rk3288: i2s_frac adds flag to set parent's rate
  doc/kernel-parameters.txt: clarify clk_ignore_unused
  arm: pxa: Transition pxa27x to clk framework
  dts: add devicetree bindings for pxa27x clocks
  clk: add pxa27x clock drivers
  arm: pxa: add clock pll selection bits
  clk: dts: document pxa clock binding
  clk: add pxa clocks infrastructure
  clk: gpio-gate: Ensure gpiod_ APIs are prototyped
  clk: ti: dra7-atl-clock: Mark the device as pm_runtime_irq_safe
  clk: ti: LLVMLinux: Move __init outside of type definition
  clk: ti: consider the fact that of_clk_get() might return an error
  clk: ti: dra7-atl-clock: fix a memory leak
  clk: ti: change clock init to use generic of_clk_init
  clk: hix5hd2: add I2C clocks
  clk: hix5hd2: add watchdog0 clocks
  ...