This patch adds a common clock driver for Silicon Labs Si5351a/b/c
i2c programmable clock generators. Currently, the driver does not
support VXCO feature of si5351b. Passing platform_data or DT bindings
selectively allows to overwrite stored Si5351 configuration which is
very helpful for clock generators with empty eeprom configuration.
Corresponding device tree binding documentation is also added.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Michal Bachraty <michal.bachraty@streamunlimited.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Add support for DT "fixed-factor-clock" binding to the common fixed
factor clock support.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Notifiers may return NOTIFY_(OK|DONE|STOP|BAD). The CCF uses an
inconsistent mix of checking against NOTIFY_STOP or NOTIFY_BAD.
This inconsistency leaves errors undetected in some cases:
clk_set_parent() calls __clk_speculate_rates(), which stops when it
hits a NOTIFIER_BAD (STOP is ignored), and passes this value back to the
caller.
clk_set_parent() compares this return value against NOTIFY_STOP only,
ignoring NOTIFY_BAD returns.

Use NOTIFY_STOP_MASK to detect a negative notifier return value and
document all four return value options.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

The patch setups the first version of the clock tree for ab850x, which
is used by u8500 platforms. Mainly sysctrl clocks are used.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

The abx500 sysctrl clocks are using the ab8500 sysctrl driver to
modify the clock hardware. Sysctrl clocks are represented by a
ab8500 sysctrl register and with a corresponding bitmask.

The sysctrl clocks are slow path clocks, which means clk_prepare
and clk_unprepare will be used to gate|ungate these clocks.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

cpu_freq_select is used as array subscript, thus the valid value range
is 0 ... ARRAY_SIZE() - 1.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up trivial merge issues]

Updating the clock tree topology must be protected with the spinlock
when doing clk_set_parent, otherwise we can not handle the migration
of the enable_count in a safe manner.

While issuing the .set_parent callback to make the clk-hw perform the
switch to the new parent, we can not hold the spinlock since it is must
be allowed to be slow path. This complicates error handling, but is still
possible to achieve.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Fixup the broken feature of allowing reparent of a clk to the
orhpan list and vice verse. When operating on a single-parent
clk, the .set_parent callback for the clk hw is optional to
implement, but for a multi-parent clk it is mandatory.

Moreover improve the errorhandling by verifying the prerequisites
before triggering clk notifiers. This will prevent unnecessary
rollback with ABORT_RATE_CHANGE.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Split __clk_reparent into three pieces, one for doing the actual
reparent for updating the clock tree topology, one for the
COMMON_CLK_DEBUG code and one for doing the rate recalculation.

This patch also makes it possible to hold the spinlock over the
update of the clock tree topology, which could not be done before
when both debugfs updates and clock rate updates was done within
the same function.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk_register will copy this information, so we can just use a normal
array and do one less dynamic allocation.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

This flag was in place to prevent important clocks from getting gated
while they had no users. Now that the UART driver supports clocks
properly, we can drop this.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

This patchset adds DT support for all the AXI, AHB, APB0 and APB1
gates present on sunxi SoCs.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Dividers which have CLK_DIVIDER_ONE_BASED set have a redundant state,
being a divider value of zero. Some hardware implementations allow a
zero divider which simply doesn't alter the frequency. I.e. it acts like
a divide by one or bypassing the divider.
This flag is used to handle such HW in the clk-divider model.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

The use common of_clk_init() function simplifies the clock initialization
and adds handling of the DT "fixed-clock".
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed $SUBJECT to reflect correct file path]

The kerneldoc comment for struct clk_mux documented the non-existent
num_clks instead of flags. Correct this.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Reentrancy into the clock framework is necessary for clock operations
that result in nested calls to the clk api.  A common example is a clock
that is prepared via an i2c transaction, such as a clock inside of a
discrete audio chip or a power management IC.  The i2c subsystem itself
will use the clk api resulting in a deadlock:

clk_prepare(audio_clk)
	i2c_transfer(..)
		clk_prepare(i2c_controller_clk)

The ability to reenter the clock framework prevents this deadlock.

Other use cases exist such as allowing .set_rate callbacks to call
clk_set_parent to achieve the best rate, or to save power in certain
configurations.  Yet another example is performing pinctrl operations
from a clk_ops callback.  Calls into the pinctrl subsystem may call
clk_{un}prepare on an unrelated clock.  Allowing for nested calls to
reenter the clock framework enables both of these use cases.

Reentrancy is implemented by two global pointers that track the owner
currently holding a global lock.  One pointer tracks the owner during
sleepable, mutex-protected operations and the other one tracks the owner
during non-interruptible, spinlock-protected operations.

When the clk framework is entered we try to hold the global lock.  If it
is held we compare the current task against the current owner; a match
implies a nested call and we reenter.  If the values do not match then
we block on the lock until it is released.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Create locking helpers for the global mutex and global spinlock.  The
definitions of these helpers will be expanded upon in the next patch
which introduces reentrancy into the locking scheme.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Include zynq clk header where init function is declared.

It removes this sparse warning:
drivers/clk/clk-zynq.c:373:13: warning: symbol
'xilinx_zynq_clocks_init' was not declared. Should it be static?
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

During the introduction of the Allwinner SoC platforms, sunxi was
initially meant as a generic name for all the variants of the Allwinner
SoC.

It was ok at the time of the support of only the A10 and A13 that
look pretty much the same; but it's beginning to be troublesome with
the future addition of the Allwinner A31 (sun6i) that is quite
different, and would introduce some weird logic, where sunxi would
actually mean in some case sun4i and sun5i but without sun6i...

Moreover, it makes the compatible strings naming scheme not consistent
with other architectures, where usually for this kind of compability, we
just use the oldest SoC name that has this IP, so let's do just this.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

This patch contains useful bits of information about the sunxi clocks
that may help and/or be interesting for current and future developers.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

This commit implements the base CPU clocks for sunxi devices. It has
been tested using a slightly modified cpufreq driver from the
linux-sunxi 3.0 tree.

Additionally, document the new bindings introduced by this patch.

Idling:
    / # cat /sys/kernel/debug/clk/clk_summary
       clock                        enable_cnt  prepare_cnt  rate
    ---------------------------------------------------------------------
     osc32k                         0           0            32768
     osc24M_fixed                   0           0            24000000
        osc24M                      0           0            24000000
           apb1_mux                 0           0            24000000
              apb1                  0           0            24000000
           pll1                     0           0            60000000
              cpu                   0           0            60000000
                 axi                0           0            60000000
                    ahb             0           0            60000000
                       apb0         0           0            30000000
     dummy                          0           0            0

After "yes >/dev/null &":
    / # cat /sys/kernel/debug/clk/clk_summary
       clock                        enable_cnt  prepare_cnt  rate
    ---------------------------------------------------------------------
     osc32k                         0           0            32768
     osc24M_fixed                   0           0            24000000
        osc24M                      0           0            24000000
           apb1_mux                 0           0            24000000
              apb1                  0           0            24000000
           pll1                     0           0            1008000000
              cpu                   0           0            1008000000
                 axi                0           0            336000000
                    ahb             0           0            168000000
                       apb0         0           0            84000000
     dummy                          0           0            0
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

In clk_reg_prcmu(), clk->hw.init field is assigned with a
reference local to clk_reg_prcmu() function.

This patch replaces references to clk->hw.init with calls
to __clk_get_name when called after clock registration.

This patch applies on top of v3.9-rc4.
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: resolved trivial merge issues]

Commit ce4f3313 (clk: add table lookup to mux) caused the following build
error on imx_v4_v5_defconfig/imx_v6_v7_defconfig:

arch/arm/mach-imx/clk-busy.c:172:11: error: 'struct clk_mux' has no member named 'width'

Fix it by passing the 'mask' field.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: shortened $SUBJECT line]

Not all clocks are required to be decomposed into basic clock
types but at the same time want to use the functionality
provided by these basic clock types instead of duplicating.

For example, Tegra SoC has ~100 clocks which can be decomposed
into Mux -> Div -> Gate clock types making the clock count to
~300. Also, parent change operation can not be performed on gate
clock which forces to use mux clock in driver if want to change
the parent.

Instead aggregate the basic clock types functionality into one
clock and just use this clock for all operations. This clock
type re-uses the functionality of basic clock types and not
limited to basic clock types but any hardware-specific
implementation.
Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Add a table lookup feature to the mux clock. Also allow arbitrary masks
instead of the width. This will be used by some clocks on Tegra114. Also
adapt the tegra periph clk because it uses struct clk_mux directly.
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Return type of function clk_propagate_rate_change is a pointer.
But 0 was being returned. Change it to NULL.
Silences the following warning:
drivers/clk/clk.c:977:24: warning: Using plain integer as NULL pointer
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Pankaj Jangra <jangra.pankaj9@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

In case of error, the function clk_get() returns ERR_PTR()
not NULL. The NULL test in the return value check should
be replaced with IS_ERR().
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: added missing parenthesis to fix compile break]

This patch corrects wrongly configured parent clock for following
devices:

   * Video enc/decoder
   * Video ip
   * Pin control
   * ACP
   * camx
Signed-off-by: Vipul Kumar Samar <vipulkumar.samar@st.com>
Reviewed-by: Shiraz Hashim <shiraz.hashim@st.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Correcting misspelling inside the clk.txt.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

This driver adds support for the AXI clkgen pcore to the common clock framework.
The AXI clkgen pcore is a AXI front-end to the MMCM_ADV frequency synthesizer
commonly found in Xilinx FPGAs.

The AXI clkgen pcore is used in Analog Devices' reference designs targeting
Xilinx FPGAs.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

To be able to gate unused prcmu clocks from the clk_disable_unused sequence,
clk-prcmu now implements the is_prepared callback.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

An unprepare_unused callback is introduced due to the same reasons to
why the disable_unused callback was added.

During the clk_disable_unused sequence, those clk_hw that needs specific
treatment with regards to being unprepared, shall implement the
unprepare_unused callback.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

The unused ungated fast clocks are already being disabled from
clk_disable_unused at late init. This patch extend this sequence
to the slow unused prepared clocks to be unprepared.

Unless the optional .is_prepared callback is implemented by a
clk_hw the clk_disable_unused sequence will not unprepare any
unused clocks, since it will fall back to use the software
prepare counter.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed hlist accessors per b67bfe0d]

To reflect whether a clk_hw is prepared the clk_hw may implement
the optional is_prepared callback. If not implemented we fall back
to use the software prepare counter.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Fix the following sparse warnings:

drivers/clk/mxs/clk.c:17:1: warning: symbol 'mxs_lock' was not declared. Should it be static?
drivers/clk/mxs/clk.c:19:5: warning: symbol 'mxs_clk_wait' was not declared. Should it be static?
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Commit 1d9d8639 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") introduces a link failure since
perf_restore_debug_store() is only defined for CONFIG_CPU_SUP_INTEL:

	arch/x86/power/built-in.o: In function `restore_processor_state':
	(.text+0x45c): undefined reference to `perf_restore_debug_store'

Fix it by defining the dummy function appropriately.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 1d9d8639 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") fixed a crash when doing PEBS performance profiling
after resuming, but in using init_debug_store_on_cpu() to restore the
DS_AREA mtrr it also resulted in a new WARN_ON() triggering.

init_debug_store_on_cpu() uses "wrmsr_on_cpu()", which in turn uses CPU
cross-calls to do the MSR update.  Which is not really valid at the
early resume stage, and the warning is quite reasonable.  Now, it all
happens to _work_, for the simple reason that smp_call_function_single()
ends up just doing the call directly on the CPU when the CPU number
matches, but we really should just do the wrmsr() directly instead.

This duplicates the wrmsr() logic, but hopefully we can just remove the
wrmsr_on_cpu() version eventually.
Reported-and-tested-by: Parag Warudkar <parag.lkml@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull btrfs fixes from Chris Mason:
 "Eric's rcu barrier patch fixes a long standing problem with our
  unmount code hanging on to devices in workqueue helpers.  Liu Bo
  nailed down a difficult assertion for in-memory extent mappings."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix warning of free_extent_map
  Btrfs: fix warning when creating snapshots
  Btrfs: return as soon as possible when edquot happens
  Btrfs: return EIO if we have extent tree corruption
  btrfs: use rcu_barrier() to wait for bdev puts at unmount
  Btrfs: remove btrfs_try_spin_lock
  Btrfs: get better concurrency for snapshot-aware defrag work

Users report that an extent map's list is still linked when it's actually
going to be freed from cache.

The story is that

a) when we're going to drop an extent map and may split this large one into
smaller ems, and if this large one is flagged as EXTENT_FLAG_LOGGING which means
that it's on the list to be logged, then the smaller ems split from it will also
be flagged as EXTENT_FLAG_LOGGING, and this is _not_ expected.

b) we'll keep ems from unlinking the list and freeing when they are flagged with
EXTENT_FLAG_LOGGING, because the log code holds one reference.

The end result is the warning, but the truth is that we set the flag
EXTENT_FLAG_LOGGING only during fsync.

So clear flag EXTENT_FLAG_LOGGING for extent maps split from a large one.
Reported-by: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>