The __clk_get_flags() symbol is exported immediately following the
clk_unprepare_unused_subtree() function. This is unusual, since a symbol
export typically follows body of the function that it exports.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Commit 71472c0c (clk: add support for clock reparent on set_rate) added a
dereference of the new_parent pointer in clk_reparent(), but as detected
by smatch clk_reparent() later checks whether new_parent is NULL.

The dereference was in order to clear the new parent's new_child pointer
to avoid duplicate POST_RATE_CHANGE notifications, so clearly isn't
necessary if the new parent is NULL, so move it inside the "if
(new_parent)" block.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Currently of_clk_init() finds a matching device node while holding
the device tree spinlock.  When a matching device node is found, the
lock is dropped and then re-acquired in order to get a reference
to the matching device id structure.

Acquiring the spinlock twice is unnecessary (and it opens a
vulnerable window that could conceivably lead to errors).

There already exists an interface for both finding and taking a
reference to a device id under lock, so use it.
Signed-off-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NChristian Daudt <csd@broadcom.com>
Reviewed-by: NMarkus Mayer <markus.mayer@linaro.org>
Reviewed-by: NMatt Porter <matt.porter@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

At some point changes to clk_set_rate and clk_set_parent introduced a
bug whereby NULL struct clk pointers were treated as an error. This is
in violation of the API in include/linux/clk.h. Reintroduce graceful
handling of NULL clk's by bailing from clk_set_rate and clk_set_parent
with return codes of zero.
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Implement clk-mux remuxing if the CLK_SET_RATE_NO_REPARENT flag isn't
set. This implements determine_rate for clk-mux to propagate to each
parent and to choose the best one (like clk-divider this chooses the
parent which provides the fastest rate <= the requested rate).

The determine_rate op is implemented as a core helper function so that
it can be easily used by more complex clocks which incorporate muxes.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Add core support to allow clock implementations to select the best
parent clock when rounding a rate, e.g. the one which can provide the
closest clock rate to that requested. This is by way of adding a new
clock op, determine_rate(), which is like round_rate() but has an extra
parameter to allow the clock implementation to optionally select a
different parent clock. The core then takes care of reparenting the
clock when setting the rate.

The parent change takes place with the help of some new private data
members. struct clk::new_parent specifies a clock's new parent (NULL
indicates no change), and struct clk::new_child specifies a clock's new
child (whose new_parent member points back to it). The purpose of these
are to allow correct walking of the future tree for notifications prior
to actually reparenting any clocks, specifically to skip child clocks
who are being reparented to another clock (they will be notified via the
new parent), and to include any new child clock. These pointers are set
by clk_calc_subtree(), and the new_child pointer gets cleared when a
child is actually reparented to avoid duplicate POST_RATE_CHANGE
notifications.

Each place where round_rate() is called, determine_rate() is checked
first and called in preference. This restructures a few of the call
sites to simplify the logic into if/else blocks.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Move some parent related functions up in clk.c so they can be used by
the modifications in the following patch which enables clock reparenting
during set_rate. No other changes are made so this patch makes no
functional difference in isolation. This is separate from the following
patch primarily to ease readability of that patch.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Abstract access to the clock parent cache by defining
clk_get_parent_by_index(clk, index). This allows access to parent
clocks from clock drivers.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Signed-off-by: NPeter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

A clock's notifier count only reflects notifiers which are registered
directly for that clock. A reparent operation though affects the whole
subtree because of a potential rate change.
When issuing the pre rate change notifications only the notifier count
for the clock to be changed is considered and notifiers for subclocks
may never be called. Resulting in clocks in the subtree which have
registered notifiers, may receive a POST_- or ABORT_RATE_CHANGE
notification, without a PRE_RATE_CHANGE_NOTIFICATION.
Therefore always traverse the whole subtree when issueing pre rate
change notifications during a reparent operation.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

clk_set_rate() uses clk->rate directly. This causes problems if the clock
is marked as CLK_GET_RATE_NOCACHE. Hence call clk_get_rate() to get the
current rate.
Signed-off-by: NPeter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

debugfs uses the rate field directly. However this ignores the
CLK_GET_RATE_NOCACHE flag. Call clk_get_rate() instead.
Tested-by: NMark Zhang <markz@nvidia.com>
Signed-off-by: NPeter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

The @cn is stay in @clk_notifier_list after it is freed, it cause
memory corruption.

Example, if @clk is registered(first), unregistered(first),
registered(second), unregistered(second).

The freed @cn will be used when @clk is registered(second),
and the bug will be happened when @clk is unregistered(second):

[  517.040000] clk_notif_dbg clk_notif_dbg.1: clk_notifier_unregister()
[  517.040000] Unable to handle kernel paging request at virtual address 00df3008
[  517.050000] pgd = ed858000
[  517.050000] [00df3008] *pgd=00000000
[  517.060000] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
[  517.060000] Modules linked in: clk_notif_dbg(O-) [last unloaded: clk_notif_dbg]
[  517.060000] CPU: 1 PID: 499 Comm: modprobe Tainted: G           O 3.10.0-rc3-00119-ga93cb29a-dirty #85
[  517.060000] task: ee1e0180 ti: ee3e6000 task.ti: ee3e6000
[  517.060000] PC is at srcu_readers_seq_idx+0x48/0x84
[  517.060000] LR is at srcu_readers_seq_idx+0x60/0x84
[  517.060000] pc : [<c0052720>]    lr : [<c0052738>]    psr: 80070013
[  517.060000] sp : ee3e7d48  ip : 00000000  fp : ee3e7d6c
[  517.060000] r10: 00000000  r9 : ee3e6000  r8 : 00000000
[  517.060000] r7 : ed84fe4c  r6 : c068ec90  r5 : c068e430  r4 : 00000000
[  517.060000] r3 : 00df3000  r2 : 00000000  r1 : 00000002  r0 : 00000000
[  517.060000] Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[  517.060000] Control: 18c5387d  Table: 2d85804a  DAC: 00000015
[  517.060000] Process modprobe (pid: 499, stack limit = 0xee3e6238)
[  517.060000] Stack: (0xee3e7d48 to 0xee3e8000)
....
[  517.060000] [<c0052720>] (srcu_readers_seq_idx+0x48/0x84) from [<c0052790>] (try_check_zero+0x34/0xfc)
[  517.060000] [<c0052790>] (try_check_zero+0x34/0xfc) from [<c00528b0>] (srcu_advance_batches+0x58/0x114)
[  517.060000] [<c00528b0>] (srcu_advance_batches+0x58/0x114) from [<c0052c30>] (__synchronize_srcu+0x114/0x1ac)
[  517.060000] [<c0052c30>] (__synchronize_srcu+0x114/0x1ac) from [<c0052d14>] (synchronize_srcu+0x2c/0x34)
[  517.060000] [<c0052d14>] (synchronize_srcu+0x2c/0x34) from [<c0053a08>] (srcu_notifier_chain_unregister+0x68/0x74)
[  517.060000] [<c0053a08>] (srcu_notifier_chain_unregister+0x68/0x74) from [<c0375a78>] (clk_notifier_unregister+0x7c/0xc0)
[  517.060000] [<c0375a78>] (clk_notifier_unregister+0x7c/0xc0) from [<bf008034>] (clk_notif_dbg_remove+0x34/0x9c [clk_notif_dbg])
[  517.060000] [<bf008034>] (clk_notif_dbg_remove+0x34/0x9c [clk_notif_dbg]) from [<c02bb974>] (platform_drv_remove+0x24/0x28)
[  517.060000] [<c02bb974>] (platform_drv_remove+0x24/0x28) from [<c02b9bf8>] (__device_release_driver+0x8c/0xd4)
[  517.060000] [<c02b9bf8>] (__device_release_driver+0x8c/0xd4) from [<c02ba680>] (driver_detach+0x9c/0xc4)
[  517.060000] [<c02ba680>] (driver_detach+0x9c/0xc4) from [<c02b99c4>] (bus_remove_driver+0xcc/0xfc)
[  517.060000] [<c02b99c4>] (bus_remove_driver+0xcc/0xfc) from [<c02bace4>] (driver_unregister+0x54/0x78)
[  517.060000] [<c02bace4>] (driver_unregister+0x54/0x78) from [<c02bbb44>] (platform_driver_unregister+0x1c/0x20)
[  517.060000] [<c02bbb44>] (platform_driver_unregister+0x1c/0x20) from [<bf0081f8>] (clk_notif_dbg_driver_exit+0x14/0x1c [clk_notif_dbg])
[  517.060000] [<bf0081f8>] (clk_notif_dbg_driver_exit+0x14/0x1c [clk_notif_dbg]) from [<c00835e4>] (SyS_delete_module+0x200/0x28c)
[  517.060000] [<c00835e4>] (SyS_delete_module+0x200/0x28c) from [<c000edc0>] (ret_fast_syscall+0x0/0x48)
[  517.060000] Code: e5973004 e7911102 e0833001 e2881002 (e7933101)

Cc: stable@kernel.org
Reported-by: NSören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Tested-by: NSören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: shortened $SUBJECT]

With deferred probing, late_initcall() is too soon to declare a clock as
unused. Wait for deferred probing to finish before declaring a clock as
unused. Since deferred probing is done in late_initcall(), do the unused
check to late_initcall_sync.
Signed-off-by: NSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Without this patch, the following race condition is possible.
* clk-A has two parents - clk-X and clk-Y.
* All three are disabled and clk-X is current parent.
* Thread A: clk_set_parent(clk-A, clk-Y).
* Thread A: <snip execution flow>
* Thread A: Grabs enable lock.
* Thread A: Sees enable count of clk-A is 0, so doesn't enable clk-Y.
* Thread A: Updates clk-A SW parent to clk-Y
* Thread A: Releases enable lock.
* Thread B: clk_enable(clk-A).
* Thread B: clk_enable() enables clk-Y, then enabled clk-A and returns.

clk-A is now enabled in software, but not clocking in hardware since the
hardware parent is still clk-X.

The only way to avoid race conditions between clk_set_parent() and
clk_enable/disable() is to ensure that clk_enable/disable() calls don't
require changes to hardware enable state between changes to software clock
topology and hardware clock topology.

The options to achieve the above are:
1. Grab the enable lock before changing software/hardware topology and
   release it afterwards.
2. Keep the clock enabled for the duration of software/hardware topology
   change so that any additional enable/disable calls don't try to change
   the hardware state. Once the topology change is complete, the clock can
   be put back in its original enable state.

Option (1) is not an acceptable solution since the set_parent() ops might
need to sleep.

Therefore, this patch implements option (2).

This patch doesn't violate any API semantics. clk_disable() doesn't
guarantee that the clock is actually disabled. So, no clients of a clock
can assume that a clock is disabled after their last call to clk_disable().
So, enabling the clock during a parent change is not a violation of any API
semantics.

This also has the nice side effect of simplifying the error handling code.
Signed-off-by: NSaravana Kannan <skannan@codeaurora.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up whitespace issue]

This is primarily useful when there's a driver that doesn't claim clocks
properly, but the bootloader leaves them on. It's not expected to be used
in normal cases, but for bringup and debug it's very useful to have the
option to not gate unclaimed clocks that are still on.
Signed-off-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up trivial merge issue]

The common clock api provides some helpers for clk-providers but does
not export these helpers. This hinders clk-providers to be built as modules.
This patch adds __clk_get_flags() to the list of exported symbols.
Signed-off-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: NMike 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: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

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: NUlf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: NMike 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: NUlf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: NMike 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: NUlf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: NMike 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: NMike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NUlf 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: NMike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NUlf Hansson <ulf.hansson@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: NSachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: NPankaj Jangra <jangra.pankaj9@gmail.com>
Signed-off-by: NMike 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: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMike 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: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMike 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: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Modify of_clk_init function so that it will determine which
driver to initialize based on device tree instead of each driver
registering to it.

Based on a similar patch for drivers/irqchip by Thomas Petazzoni and
drivers/clocksource by Stephen Warren.
Signed-off-by: NPrashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: NTony Prisk <linux@prisktech.co.nz>
Tested-by: NPawel Moll <pawel.moll@arm.com>
Tested-by: NRob Herring <rob.herring@calxeda.com>
Tested-by: NJosh Cartwright <josh.cartwright@ni.com>
Reviewed-by: NJosh Cartwright <josh.cartwright@ni.com>
Acked-by: NMaxime Ripard <maxime.ripard@anandra.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: merge conflict from missing CLKSRC_OF_TABLES()]
Signed-off-by: NMike Turquette <mturquette@linaro.org>

On non-out case 'return ret;' is equivalent to 'return 0;' as the ret
variable is initialized at 0 and never changed.
Signed-off-by: NNestor Ovroy <novroy@riseup.net>

Clock information is dumped in JSON format which is easy
for machines to parse.

Each clock is represented as an object which has same name as
clock and following properties
	- enable_count
	- prepare_count
	- rate

Output is verified using online JSON editor.
Signed-off-by: NPrashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Adds debug file "clk_summary" in /sys/kernel/debug/clk dir.
It helps to view all the clock registered in human-readable format.

For example:
   clock                        enable_cnt  prepare_cnt  rate
---------------------------------------------------------------------
 i2s0_sync                      0           0            24000000
 spdif_in_sync                  0           0            24000000
    spdif_mux                   0           0            24000000
       spdif                    0           0            24000000
          spdif_doubler         0           0            48000000
             spdif_div          0           0            48000000
                spdif_2x        0           0            48000000
 clk_32k                        2           2            32768
    blink_override              1           1            32768
       blink                    1           1            32768
 clk_m                          2           2            12000000
    clk_out_3_mux               0           0            12000000
       clk_out_3                0           0            12000000
    pll_ref                     3           3            12000000
       pll_e_mux                0           0            12000000
          pll_e                 0           0            100000000
             cml0               0           0            100000000
             cml1               0           0            100000000
             pciex              0           0            100000000
       pll_d2                   0           0            1000000
          pll_d2_out0           0           0            500000
       pll_d                    0           0            1000000
          pll_d_out0            0           0            500000
             dsib_mux           0           0            500000
                dsib            0           0            500000
             dsia               0           0            500000
Signed-off-by: NPrashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

This fixes the following error when building for arm-imx:
> ERROR: "__clk_get_name" [drivers/staging/imx-drm/ipu-v3/imx-ipu-v3.ko] undefined!
> make[1]: *** [__modpost] Error 1
> make: *** [modules] Error 2

There are valid usecases to get the name of a clock, be it for debugging
purposes or to register a children of a clock like done in this IPU driver.
Therefore exporting __clk_get_name() and make it available for others makes
sense.
Reported-by: NPeter Robinson <pbrobinson@gmail.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
CC: Mike Turquette <mturquette@linaro.org>
Signed-off-by: NNiels de Vos <ndevos@redhat.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removal of inline made redundant by 65800b2c]

The helper functions that access the opaque struct clk should
not be marked inline since they are contained in clk.c, but expected
to be used by other compilation units. This causes compile errors
under gcc-4.7

In file included from arch/arm/mach-omap2/clockdomain.c:25:0:
arch/arm/mach-omap2/clockdomain.c: In function ‘clkdm_clk_disable’:
include/linux/clk-provider.h:338:12: error: inlining failed in call to always_inline ‘__clk_get_enable_count’: function body not available
arch/arm/mach-omap2/clockdomain.c:1001:28: error: called from here
make[1]: *** [arch/arm/mach-omap2/clockdomain.o] Error 1
make: *** [arch/arm/mach-omap2] Error 2
Signed-off-by: NRuss Dill <Russ.Dill@ti.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removed fixes made redundant by commit 93532c8a]
[mturquette@linaro.org: improved $SUBJECT]

Some gate clocks have special needs which must be handled during the
disable-unused clocks sequence.  These needs might be driven by software
due to the fact that we're disabling a clock outside of the normal
clk_disable path and a clk's enable_count will not be accurate.  On the
other hand a specific hardware programming sequence might need to be
followed for this corner case.

This change is needed for the upcoming OMAP port to the common clock
framework.  Specifically, it is undesirable to treat the disable-unused
path identically to the normal clk_disable path since other software
layers are involved.  In this case OMAP's clockdomain code throws WARNs
and bails early due to the clock's enable_count being set to zero.  A
custom callback mitigates this problem nicely.

Cc: Paul Walmsley <paul@pwsan.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

When a clock, C is initialised any orphan clocks listing C as
a possible parent are reparented to it regardless of the
parent requested by the orphan's get_parent() operation.

This means that multiplexers registered before their parents
are reparented to the first parent subsequently declared,
regardless of the selection made by the hardware registers.

For example:
	static const char *sel[] = { "srcA", "srcB", "dummy", "srcC" };

	child = clk_register_mux(NULL, "child",  sel, ARRAY_SIZE(sel), ...);
	clk_register_fixed(NULL, "dummy", ...);
	clk_register_fixed(NULL, "srcA", ...);
	clk_register_fixed(NULL, "srcB", ...);
	clk_register_fixed(NULL, "srcC", ...);

Causes child's parent to always be "dummy".

To fix this, when an orphanned clock has a get_parent() operation,
only reparent to the clock indicated by get_parent().
Signed-off-by: NMartin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: improve $SUBJECT]

Some clock drivers can be simplified if devres takes care of
unregistering any registered clocks along error paths. Introduce
devm_clk_register() so that clock drivers get unregistration for
free along with simplified error paths.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Some of the helper functions return negative error codes if
passed a NULL clock. This can lead to confusing behavior when the
expected return value is unsigned. Fix up these accessors so that
they return unsigned values (or bool in the case of is_enabled).
This way we can't interpret NULL clocks as having valid and
interesting values.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

For those SoCs that have hundreds of clock outputs, their clock
DT bindings could reasonably define #clock-cells as 1 and require
the client device specify the index of the clock it consumes in the
cell of its "clocks" phandle.

Add a generic of_clk_src_onecell_get() function for this purpose.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Reviewed-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

By using CLK_GET_RATE_NOCACHE flag, we tell the clk_get_rate API to
issue the hw for an updated clock rate. This can be used for a clock
which rate may be updated without a client necessary modifying it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>